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This feed contains articles for bioRxiv Subject Collection "Microbiology"
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<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.15.725383v1?rss=1">
<title>
<![CDATA[
Glyphosate, a herbicide, and fosfomycin, an antibiotic in clinical use- evidence of common selectable genotypes 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.15.725383v1?rss=1
</link>
<description><![CDATA[
The emergence of antimicrobial resistance (AMR) is increasingly linked to metabolic adaptation, yet the evolutionary routes underlying cross-resistance between structurally related compounds remain poorly understood. Here, whole genome sequencing (WGS) was used to analyse Klebsiella pneumoniae mutants evolved under sub-lethal glyphosate (GLP) or fosfomycin (FOS) exposure to determine how these stresses shape resistance and physiology. Sub-lethal GLP exposure increased FOS resistance, demonstrating cross-resistance between the two phosphonates. FOS-evolved mutants achieved high-level resistance through the accumulation of multiple mutations affecting the antibiotic target MurA, transport systems, and global metabolic regulation, producing a layered FOS resistance phenotype. In contrast, GLP-evolved mutants acquired similar functional classes of mutations but exhibited lower baseline FOS resistance, suggesting trade-offs between resistance and metabolic fitness. Further, analysis of FOS-evolved and GLP-evolved mutants across known bacterial GLP resistance mechanisms demonstrated a strong overlap. Comparative genomic analysis revealed a small, recurrent set of genes under selection in both evolutionary trajectories, with identical genomic loci repeatedly targeted, consistent with convergent evolution. Many of these changes were linked to central metabolism, redox balance, and cell surface regulation. For some isolates, a hypermutator phenotype was necessary to offset the potentially lethal effects of primary-target mutations through compensatory genomic adaptation. In conclusion, GLP and FOS select for shared adaptive networks that couple metabolic rewiring with AMR, revealing cross-resistance as an emergent property of global physiological reprogramming and providing mechanistic insight into ecological models of co-selection in environmental systems.
]]></description>
<dc:creator><![CDATA[ Fanning, S., Wall, K. D., Campbell, A., Marmion, M., Kilroy, A., Doyle, C., Marshall, H. ]]></dc:creator>
<dc:date>2026-05-26</dc:date>
<dc:identifier>doi:10.64898/2026.05.15.725383</dc:identifier>
<dc:title><![CDATA[Glyphosate, a herbicide, and fosfomycin, an antibiotic in clinical use- evidence of common selectable genotypes]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-26</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.24.727525v1?rss=1">
<title>
<![CDATA[
Antigenic characterization of SARS-CoV-2 variants BA.3.2.1 and BA.3.2.2 in three animal models 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.24.727525v1?rss=1
</link>
<description><![CDATA[
BA.3.2 is a variant of SARS-CoV-2 containing ~40 mutations to its spike protein compared to its nearest ancestor, which has spread globally since its first detection in South Africa in November 2024. Here, we report antigenic characterization of BA.3.2 viruses in three naive animal models, and visualize its antigenic phenotype in the context of SARS-CoV-2 evolution using antigenic cartography. We find that: (1) BA.3.2 is substantially antigenically divergent from existing SARS-CoV-2 variants; (2) infection with BA.3.2 in hamster and mouse animal models produces sera with lower homologous titer than infection with other variants. Both of these results may have implications for the selection of vaccine antigens.
]]></description>
<dc:creator><![CDATA[ Turner, S. A., Olivier, J., Ellis, M. L., Floyd, K. A., Lai, L., Scheaffer, S. M., Hastings, I., Darling, T. L., Miller, B. A., Patel, C. J., Peck, H., Vanover, D., Santangelo, P. J., Diamond, M. S., Suthar, M. S., Boon, A. C. M., Smith, D. J. ]]></dc:creator>
<dc:date>2026-05-26</dc:date>
<dc:identifier>doi:10.64898/2026.05.24.727525</dc:identifier>
<dc:title><![CDATA[Antigenic characterization of SARS-CoV-2 variants BA.3.2.1 and BA.3.2.2 in three animal models]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-26</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.26.727115v1?rss=1">
<title>
<![CDATA[
First evaluation of a human DPP4 transgenic hamster model for MERS-CoV pathogenesis and transmission 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.26.727115v1?rss=1
</link>
<description><![CDATA[
MERS-CoV poses a constant pandemic risk, as its viral lineages continue evolving, and zoonotic spillover events could lead to random viral polymorphisms that might lead to human adapted variants. Currently, no small animal model reliably recapitulates both disease progression and transmission dynamics, which are critical aspects for counter-viral measures like vaccine development. Although the Syrian hamster is an optimal animal model for SARS-CoV-2 infection and transmission, it is naturally resistant to MERS-CoV infection. Dipeptidyl peptidase-4 (DPP4) is the functional receptor for MERS-CoV infection, and is highly expressed in human kidney, intestine, liver, and lung tissues. Here, we evaluated the suitability of a human DPP4 (hDPP4) transgenic Syrian hamster model for MERS-CoV research. We used two different MERS-CoV strains (EMC/2012 and D10540/2023) for intranasal inoculation of hamsters. Both strains replicated efficiently, led to comparable severe clinical outcomes, and had similar viral transmission efficiencies. MERS-CoV RNA and nucleoprotein antigen were mainly detected in the brain and the respiratory tract. In summary, we validated a novel hDPP4-transgenic hamster as a suitable model for MERS-CoV infection enabling vaccine and transmission research.
]]></description>
<dc:creator><![CDATA[ Schön, J., Liu, Y., Halwe, N. J., Britzke, T., Codjia Risch, M.-C. B., Li, R., Merrill, N., Ulrich, L., Rodon, J., Bork, J., Bösel, D., Beyer, A., Müller, M. A., Drosten, C., Breithaupt, A., Hoffmann, D., Wang, Z., Beer, M. ]]></dc:creator>
<dc:date>2026-05-26</dc:date>
<dc:identifier>doi:10.64898/2026.05.26.727115</dc:identifier>
<dc:title><![CDATA[First evaluation of a human DPP4 transgenic hamster model for MERS-CoV pathogenesis and transmission]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-26</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.26.725122v1?rss=1">
<title>
<![CDATA[
Transgenic human dipeptidyl peptidase-4 Syrian hamsters support MERS coronavirus infection and contact transmission 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.26.725122v1?rss=1
</link>
<description><![CDATA[
Middle East respiratory syndrome coronavirus (MERS-CoV) is a global health concern due to a high fatality rate associated with human infections and no approved vaccines or therapeutics. While Syrian hamsters are a value animal model for coronavirus research, including SARS-CoV-2, MERS-CoV does not infect wild-type hamsters. Here, we generated transgenic Syrian hamsters expressing human dipeptidyl peptidase-4 (hDPP4), the cellular receptor for MERS-CoV., MERS-CoV replicated efficiently in the respiratory tract tissues of hDPP4 hamsters, causing lethal disease. Treatment with the 3CLpro inhibitor nirmatrelvir significantly reduced viral titers in the lower respiratory tract of infected hDPP4 hamsters. While airborne transmission was not observed, direct contact transmission was observed in all contact hDPP4 hamsters cohoused with infected cage mates. Immunization with purified MERS receptor-binding domain protein reduced virus replication and disease severity but did not prevent direct contact transmission. Collectively, our findings demonstrate that hDPP4 transgenic Syrian hamsters are useful for studying MERS-CoV pathogenesis, transmission, and countermeasure efficacy.
]]></description>
<dc:creator><![CDATA[ Wang, T., Liu, Y., Li, R., Merrill, N., Wang, Z., Halfmann, P. ]]></dc:creator>
<dc:date>2026-05-26</dc:date>
<dc:identifier>doi:10.64898/2026.05.26.725122</dc:identifier>
<dc:title><![CDATA[Transgenic human dipeptidyl peptidase-4 Syrian hamsters support MERS coronavirus infection and contact transmission]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-26</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.727690v1?rss=1">
<title>
<![CDATA[
Dynamic partitioning shapes the in vivo organization of the E. coli RNA degradosome 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.727690v1?rss=1
</link>
<description><![CDATA[
Macromolecular scaffolds are often viewed as fully assembled molecular machines with fixed stoichiometry. Here, we show that the Escherichia coli RNA degradosome follows a more dynamic organizational principle. Using live-cell single-molecule imaging, we quantified the spatial distribution, diffusion, and stoichiometry of RNase E and its accessory factors RhlB, PNPase, and enolase in vivo. The membrane-associated stoichiometry of RhlB and PNPase was broadly consistent with canonical expectation, whereas enolase was underrepresented in the membrane-bound degradosome. In contrast to the near-complete membrane association of RhlB, PNPase partitioned substantially between membrane-associated and cytoplasmic pools, and this partitioning shifted with RNA availability and growth condition. Using lacZ reporters with different translation initiation strengths, we further show that RhlB and PNPase preferentially promote degradation of weakly translated transcripts, whereas strongly translated transcripts are largely insensitive to their loss. Together, these results support a model in which the E. coli RNA degradosome is a membrane-anchored but dynamically assembled complex, with accessory factors contributing differently across physiological states and RNA substrate classes.
]]></description>
<dc:creator><![CDATA[ Troyer, L., Wang, Y.-H., Wu, K., Kim, S., Kim, S. ]]></dc:creator>
<dc:date>2026-05-26</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.727690</dc:identifier>
<dc:title><![CDATA[Dynamic partitioning shapes the in vivo organization of the E. coli RNA degradosome]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-26</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.22.727251v1?rss=1">
<title>
<![CDATA[
Substrate and target selectivity of 4'-fluoroadenosine against viral and host polymerases 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.22.727251v1?rss=1
</link>
<description><![CDATA[
Developing safe and effective treatments against emerging RNA viruses is an important goal in pandemic preparedness efforts. 4'-fluorouridine (4'-FlU) is a broad-spectrum antiviral that was shown to inhibit viral RNA-dependent RNA polymerases (RdRps). Given its notable range of antiviral activity, this class of nucleoside analogs warrants further investigation. Here, we studied the antiviral activity and underlying mechanism of inhibition of 4'-fluoroadenosine (4'-FlA). Like 4'-FlU, 4'-FlA demonstrates a broad-spectrum of antiviral activity against eight prototypic viruses representing diverse families. Enzyme kinetics show that the triphosphate (4'-FlA-TP) is efficiently incorporated by viral RdRps. A cryo-EM structure of RdRp of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in complex with double-stranded RNA and the incorporated monophosphate (4'-FlA-MP) characterizes interactions at the active site. The incorporated analog elicits heterogeneous inhibition patterns in primer extension reactions. In contrast, templates with embedded 4'-FlA-MP inhibit incorporation of complementary UTP across the viral RdRps. However, incorporation of 4'-FIA-TP is not limited to viral polymerases and likewise includes human mitochondrial RNA polymerase. These results demonstrate the general potential for 4'-fluorinated nucleotides as antiviral drugs and guide the development of more selective derivatives for medical use in appropriate settings.
]]></description>
<dc:creator><![CDATA[ Walker, S. M., Loutan, A. J., Tchesnokov, E. P., Kocincova, D., Gordon, C. J., Escobedo, R. A., Jackson, N., Vogel, O. A., Morsheimer, K., Park, S., Gharpure, A., Urbano, I., Heacock, M., Cheng, Z., Pathak, K., Wolff, K. C., Huerta, L., Bakowski, M. A., Riva, L., Gupta, A. K., Yu, C., Das, K., Martinez-Sobrido, L., Basler, C. F., Davey, R. A., Wilson, I. A., Ward, A. B., Chanda, S., Chatterjee, A. K., Gotte, M. ]]></dc:creator>
<dc:date>2026-05-26</dc:date>
<dc:identifier>doi:10.64898/2026.05.22.727251</dc:identifier>
<dc:title><![CDATA[Substrate and target selectivity of 4'-fluoroadenosine against viral and host polymerases]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-26</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.26.727833v1?rss=1">
<title>
<![CDATA[
A fungal pathogen effector that shapes host plant microbiota kills bacteria through lipoteichoic acid binding and membrane disruption 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.26.727833v1?rss=1
</link>
<description><![CDATA[
Antimicrobial proteins are ancient and widespread molecules that contribute to survival across all domains of life. We previously showed that fungal plant pathogens secrete antimicrobial proteins to suppress antagonistic members of the host microbiota and thereby promote host colonization. The soil-borne plant pathogen Verticillium dahliae employs the bactericidal protein VdAve1 for this purpose. Here, we elucidate the mode of action of VdAve1 and define its mechanism as a distinct type of antimicrobial activity. Nuclear magnetic resonance (NMR) analysis revealed that VdAve1 adopts a jelly-roll barrel-like fold. Functionally, VdAve1 disrupts bacterial plasma membranes, and synthetic peptides derived from its positively charged regions retain antimicrobial activity, indicating that these regions contribute to its function. We further show that the bacterial model system Bacillus subtilis responds to VdAve1 by modifying teichoic acids, and that loss of these modifications increases bacterial sensitivity. Consistent with this, VdAve1 binds lipoteichoic acid (LTA), a major component of the Gram-positive cell wall. Together, our findings support a model in which VdAve1 binds LTA to localize at the bacterial surface, where it perturbs the plasma membrane, leading to membrane collapse and cell death.
]]></description>
<dc:creator><![CDATA[ Petti, G., Snelders, N., Rout, A., Wang, B., Koenig, K., Siersma, T., Biboy, J., Vollmer, W., Hamoen, L. W., Mesters, J., Friedrich, D., Mallagaray, A., Thomma, B. ]]></dc:creator>
<dc:date>2026-05-26</dc:date>
<dc:identifier>doi:10.64898/2026.05.26.727833</dc:identifier>
<dc:title><![CDATA[A fungal pathogen effector that shapes host plant microbiota kills bacteria through lipoteichoic acid binding and membrane disruption]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-26</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.26.727599v1?rss=1">
<title>
<![CDATA[
Beyond the Billion: Dose-Response Immunophenotyping and Machine Learning Classification of Live versus Heat-Inactivated Gram-Positive Probiotic Strains in Human Peripheral Blood Mononuclear Cells 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.26.727599v1?rss=1
</link>
<description><![CDATA[
Probiotic research is constrained by three pervasive yet insufficiently challenged assumptions: the requirement for a minimum of one billion colony-forming units for efficacy, the necessity for gut colonization, and the inherent superiority of live over inactivated preparations. This study addresses these gaps through a fully factorial experimental design evaluating ten Gram-positive probiotic strains in both viable (Active Fluorescent Units, AFU) and heat-inactivated (Total Fluorescent Units, TFU) forms across three flow cytometry-verified concentrations (105, 106, 107 cells/well per ISO 19344:2015) in primary human peripheral blood mononuclear cells (PBMC) from a single healthy male Caucasian donor (58 years), with simultaneous quantification of 17 cytokines by BioPlex suspension array. Viable preparations induced profoundly greater absolute cytokine responses than heat-inactivated preparations across 14 of 17 analytes, heat-inactivated preparations demonstrated stronger dose-response correlations (mean within-strain Spearman {rho} up to 1.00) for 13 of 17 cytokines, a finding we attribute to the uncontrolled proliferation of live bacteria during 24-hour co-culture compressing the effective concentration range. Six of ten viable strains exhibited monotonically increasing profiles; two strains displayed non-monotonic bell-shaped kinetics with peak activity at 106 AFU/well and significant attenuation at 107, directly falsifying the assumption that dose escalation uniformly increases immunological activity. MCP-1 was the sole cytokine showing no significant difference between viability states (p = 0.61, fold-change 1.1), providing an internal methodological control. In this single-donor model, unsupervised hierarchical clustering identified three immunological phenotype clusters, requiring multi-donor validation before these groupings can be treated as generalizable biological phenotypes, with Random Forest classification achieving 86.7% internal partition-recovery consistency (clusters derived from the same data; not an estimate of generalization to novel strains) versus 33.3% chance; In this single-donor experiment, IL-13, IL-12p70, and IFN-{gamma}, not IL-6 or IL-1{beta}, were the primary discriminators of strain identity; generalizability of this ranking requires multi-donor validation. Heat-inactivated preparations achieved [&ge;]70% functional equivalence relative to viable preparations at 107 TFU/well for the majority of responsive strains (Functional Equivalence Dose, FED70), while one strain remained immunologically inert in heat-inactivated form across all concentrations, a finding subject to the caveat that no positive control stimulus was included to formally verify PBMC functional competence on the experimental day. These findings establish a methodological framework integrating flow cytometric standardization, multiplex immunophenotyping, and machine learning for evidence-based dose characterization, postbiotic functional equivalence assessment, and data-driven strain classification in probiotic research (all p-values are descriptive within a single-donor experimental context).
]]></description>
<dc:creator><![CDATA[ Deusebio, G., Visciglia, A., Amoruso, A., Pane, M. ]]></dc:creator>
<dc:date>2026-05-26</dc:date>
<dc:identifier>doi:10.64898/2026.05.26.727599</dc:identifier>
<dc:title><![CDATA[Beyond the Billion: Dose-Response Immunophenotyping and Machine Learning Classification of Live versus Heat-Inactivated Gram-Positive Probiotic Strains in Human Peripheral Blood Mononuclear Cells]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-26</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.24.727512v1?rss=1">
<title>
<![CDATA[
Genome-resolved house microbiome exhibits location-specific metabolic partitioning, and harbors hosts with clinically relevant antibiotic resistance genes 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.24.727512v1?rss=1
</link>
<description><![CDATA[
Residential indoor surfaces are recognized as diverse microbial ecosystems, while their genome-based organization and functional repertoires remain understudied. We recovered 2304 metagenome-assembled genomes (MAGs) from shotgun metagenomic sequencing of 10 houses in New Delhi, India. Genome-resolved analysis revealed a highly structured microbial community and substantial unexplored diversity, with 60% Species-level Genome Bins (SGBs) (629/1014) unclassified at the species level. Metabolism reveals a conserved metabolic core, along with spatial functional enrichment: the living area was significantly different from the bathroom and kitchen areas. The prevalent MAG species of the house microbiome, Paracoccus marcusii, Ottowia sp. 018060485, and Kocuria palustris, showed strain-level diversity with no stratification by house, but a subtle location-wise grouping. Potential pathogens, along with a wide range of antimicrobial resistance genes (ARGs), were identified across the MAGs, with 64 ARGs associated with mobile elements. Phylogenomic analysis of Escherichia coli MAGs indicated a split between commensal-like fecal lineages and pathotype-associated clusters, like Intestinal Pathogenic E. coli (InPEC). These results suggest that residential house microbiomes harbor microbial communities with both diverse metabolic capacity and clinical relevance. Together, these findings establish a reference for future indoor microbiome research and provide a foundation for antimicrobial resistance surveillance and the development of bio-informed building-infrastructures.
]]></description>
<dc:creator><![CDATA[ Awasthi, S., Sharma, R. ]]></dc:creator>
<dc:date>2026-05-26</dc:date>
<dc:identifier>doi:10.64898/2026.05.24.727512</dc:identifier>
<dc:title><![CDATA[Genome-resolved house microbiome exhibits location-specific metabolic partitioning, and harbors hosts with clinically relevant antibiotic resistance genes]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-26</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.24.727567v1?rss=1">
<title>
<![CDATA[
Purine and pyrimidine analogues differentially regulate cell wall precursor biosynthesis to control β-lactam susceptibility in methicillin resistant Staphylococcus aureus 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.24.727567v1?rss=1
</link>
<description><![CDATA[
Maintaining the efficacy of {beta}-lactam antibiotics against Staphylococcus aureus is a clinical priority given the prevalence of methicillin-resistant S. aureus (MRSA). We previously showed that the pyrimidine analogues 5-fluorouracil (5-FU) and 5-fluorouridine (5-FUrd) synergize with {beta}-lactams. Here, we extended this by evaluating additional nucleotide metabolism-targeting agents. Gemcitabine (Gem) and mitomycin C (Mito), like 5-FU and 5-FUrd, exhibited intrinsic anti-MRSA activity and potentiated {beta}-lactams, whereas the purine analogue 6-thioguanine (6-TG) showed distinct, often antagonistic effects. Transcriptomic analysis revealed that pyrimidine-targeting agents repress lysine and glutamate biosynthesis, while 6-TG induced these pathways, implicating amino acid metabolism in {beta}-lactam potentiation. Consistent with this, pyrimidine analogues also suppressed GlmS expression, potentially limiting UDP-GlcNAc production required for cell wall synthesis, and synergized with fosfomycin. Fluorescence microscopy confirmed that the potentiation of oxacillin activity by pyrimidine-targeting agents, but not 6-TG, was accompanied by impaired peptidoglycan synthesis. Additionally, glutathione-mediated attenuation of killing implicated reactive oxygen species in the bactericidal activity of cloxacillin combinations. Finally, these agents displayed strong anti-biofilm activity, further enhanced in combination with daptomycin and rifampicin. Together, these findings highlight the potential of pyrimidine analogues to potentiate cell wall-targeting antibiotics and identify an important role for modulation of cell wall precursor pathways in this anti-MRSA activity.
]]></description>
<dc:creator><![CDATA[ Nolan, A. C., Byrne, S., Zeden, M. S., O'Gara, J. P. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.24.727567</dc:identifier>
<dc:title><![CDATA[Purine and pyrimidine analogues differentially regulate cell wall precursor biosynthesis to control β-lactam susceptibility in methicillin resistant Staphylococcus aureus]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.727442v1?rss=1">
<title>
<![CDATA[
Evaluation of orange pulping residues as an alternative growth medium for Thraustochytrium sp. 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.727442v1?rss=1
</link>
<description><![CDATA[
In this study, the lipid content produced by Thraustochytrium sp. in a medium prepared from orange pulp residue was compared with that obtained in a conventional medium. The pulp residue was subjected to freezing, blending, and filtration in seawater to prepare three treatments: conventional medium (T1), filtrate (T2), and filtrate supplemented with KNO (T3). A growth curve was performed over six days, after which biomass and lipid content were analyzed. The results showed that T2 exhibited the highest cell growth and biomass yield (5.24 g/L). However, lipid content was higher in the conventional medium (38.75%), whereas the treatments containing orange extract showed lower values. These findings suggest that the medium prepared from orange pulp residue is feasible for the growth of Thraustochytrium sp., but requires optimization to enhance lipid accumulation and its potential use in sustainable bioprocesses.
]]></description>
<dc:creator><![CDATA[ Ramos Cespedes, J., Castillo Fernandez-Davila, S., Navarro Segura, R., Dumet Poma, Y., Munoz Titto, S. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.727442</dc:identifier>
<dc:title><![CDATA[Evaluation of orange pulping residues as an alternative growth medium for Thraustochytrium sp.]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.23.727450v1?rss=1">
<title>
<![CDATA[
Heterologous expression in E. coli reveals the bicarbonate transporter BicA2 drives carbon uptake in marine Prochlorococcus spp. 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.23.727450v1?rss=1
</link>
<description><![CDATA[
The widespread oceanic cyanobacterial Prochlorococcus genus is a major contributor to global carbon fixation, yet mechanisms enabling this lineage to elevate intracellular inorganic carbon as a substrate for photosynthesis remain unresolved. Cyanobacterial CO2 concentrating mechanisms typically rely on membrane-bound bicarbonate (HCO3-) transporters SbtA1, SbtA2, BicA and BCT1, and CO2-to-HCO3- conversion uptake systems (CO2 pumps; NDH-I3 and NDH-I4), to elevate a cellular HCO3- pool for use by Rubisco-containing carboxysomes. Evidence suggests Prochlorococcus harbours carboxysomes with a low-CO2-specificity Rubisco, implying a functional CCM dependent on active HCO3- uptake. However, canonical CO2 pumps are absent, leaving distant HCO3- transporter homologues, BicA2 and SbtA2, as prime candidates for HCO3- transport in this group. Yet these have not been functionally characterised. Here we demonstrate that BicA2 from P. marinus CCMP1375 mediates Na+-dependent HCO3- uptake in E. coli, while BicA2 from P. marinus CCMP1986 is inactive in its native form but acquired transport function through a single amino acid substitution during adaptive laboratory evolution. These findings confirm BicA2 as a low-affinity, Na+-dependent bicarbonate transporter with variable flux, revealing a previously uncharacterized CCM component in Prochlorococcus. This mechanistic insight reshapes our understanding of carbon acquisition strategies in the most abundant photosynthetic organism on Earth and highlights evolutionary plasticity in transporter function with implications for global biogeochemical cycles.
]]></description>
<dc:creator><![CDATA[ Rourke, L. M., Byrt, C. S., Price, G. D., Long, B. M. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.23.727450</dc:identifier>
<dc:title><![CDATA[Heterologous expression in E. coli reveals the bicarbonate transporter BicA2 drives carbon uptake in marine Prochlorococcus spp.]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.24.727406v1?rss=1">
<title>
<![CDATA[
Computational prediction resolves thousands of homooligomeric phage protein structures 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.24.727406v1?rss=1
</link>
<description><![CDATA[
Bacteriophages (phages) play essential roles in microbial systems, yet most phage proteins remain poorly characterised. Protein tertiary and quaternary structure information contributes valuable information about protein function. As many phage proteins function as homooligomers, complexes that consist of multiple identical subunits, there is great interest in computationally predicting their configurations. Here we present a computational framework, the Phage Homomer Level Estimate and Generation Method (PHLEGM) for inferring homooligomeric states directly from the protein sequence by combining AlphaFold-Multimer modelling with inter-subunit interface quality assessment. We proceeded to experimentally validate two out of nine predicted homooligomers using size exclusion chromatography and complementary hydrodynamic techniques. These efforts confirmed our predictions for a dimer and a trimer, highlighting the value of experimentally benchmarked computational predictions and showing the challenges of heterologous phage protein production. Applied to >22,000 phage protein sequences in the PHROGs database, our approach revealed extensive diversity in phage homooligomeric protein complexes. Benchmarking against protein language model-based predictors on a curated reference set of known phage homooligomers demonstrated superior accuracy of our structure-based method, achieving robust performance in classifying protein homooligomeric states, with the highest accuracy observed for trimers and higher-order complexes. These results highlight the value of computational predictions to decipher the complexities of the vast viral sequence space. All predicted complex structures and functional inferences are made publicly available to support structural and functional studies of phage proteins.
]]></description>
<dc:creator><![CDATA[ Grigson, S. R., Geliashvili, N., Schubert, T., Bouras, G., Mallawaarachchi, V., Bogacz, M., Hellmich, U., Edwards, R. A., Dutilh, B. E. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.24.727406</dc:identifier>
<dc:title><![CDATA[Computational prediction resolves thousands of homooligomeric phage protein structures]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.23.727404v1?rss=1">
<title>
<![CDATA[
Identification of Novel Gamma Radiation-Responsive Genes in the Thiosulfate-Oxidizing Bacterium Limnobacter thiooxidans 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.23.727404v1?rss=1
</link>
<description><![CDATA[
Ionizing radiation induces DNA damage and oxidative stress; however, the genes and molecular mechanisms involved in bacterial stress responses have not been sufficiently identified. In this study, we used Limnobacter thiooxidans strain CS-K2, which is the closest relative to the bacteria detected in torus room water at the Fukushima Daiichi Nuclear Power Plant according to 16S rRNA gene sequences, and evaluated its response to {gamma}-ray irradiation using integrated transcriptomic and proteomic analyses. We identified three previously uncharacterized genes (LT3105, LT3115, and LT3126) that were strongly induced at the mRNA and protein levels. These genes exhibited low basal expression but were markedly upregulated by {gamma}-ray irradiation. Notably, LT3126 encodes a protein containing VIT (vault protein inter--trypsin) and VWA (von Willebrand factor type A) domains and showed the strongest induction. Overexpression of LT3126 increased survival after 500 Gy irradiation by approximately 200-fold compared with the control bacteria, demonstrating a direct contribution to survival under high-dose stress. Comparative genomic analysis showed that these genes are not widely conserved across bacteria but are unevenly distributed among specific lineages. Taken together, this study identified a novel set of {gamma}-ray-responsive genes and demonstrated a functional role for LT3126 in radiation resistance, providing new insights into molecular adaptation in radiation-associated environments.
]]></description>
<dc:creator><![CDATA[ Warashina, T., Sato, A., Dotsuta, Y., Kitagaki, T., Masuda, T., Ikeda, H., Kataoka, M., Morita, T., Kanai, A. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.23.727404</dc:identifier>
<dc:title><![CDATA[Identification of Novel Gamma Radiation-Responsive Genes in the Thiosulfate-Oxidizing Bacterium Limnobacter thiooxidans]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.23.727376v1?rss=1">
<title>
<![CDATA[
A billion-year-old bacterial machinery replicates plastid DNA and supports kleptoplastidy 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.23.727376v1?rss=1
</link>
<description><![CDATA[
The endosymbiotic evolution of plastids and mitochondria was central to the origin and success of eukaryotes. One of the most prominent molecular machineries thought to have disappeared early in eukaryote evolution is the multi-subunit bacterial DNA polymerase III (DNApol-III), which is the principal enzyme complex supporting DNA replication in bacteria. Here, we combined worldwide metagenomics and cultivation to characterise the mosaic genomic landscape of abundant phytoplankton lineages of Teleaulax (Cryptophyceae), which contain an endosymbiotically-derived nucleomorph genome. Unexpectedly, the nuclear, plastid and nucleomorph genomes of Teleaulax contain ubiquitously expressed genes for plastid-targeted DNApol-III subunits. These genes shed light on the functioning of Teleaulax genomes when sequestered by the ciliate Mesodinium during its kleptoplastidic photosynthetic activity. In particular, the alpha subunit gene (encoding the polymerase activity), which resides in the nucleomorph genome, is continuously expressed in Mesodinium in controlled laboratory experiments. This provides a mechanistic explanation for the replication of Teleaulax plastid genomes weeks after the nuclear genome is lost. Beyond Teleaulax and close relatives, we also identified genes encoding plastid-targeted DNApol-III subunits (including alpha) in nuclear genomes of unicellular and multicellular lineages of Archaeplastida that form, along with those of Cryptophyceae, monophyletic clades firmly positioned within Cyanobacteria. Together, our results reveal a previously overlooked retention of bacterial DNA replication machinery from plastid primary endosymbiosis in Archaeplastida, its acquisition by Cryptophyceae during secondary endosymbiosis, and its direct role in contemporary plankton as a facilitator of kleptoplastidic photosynthetic activity by heterotrophic ciliates.
]]></description>
<dc:creator><![CDATA[ Antoine, T., Burki, F., Archibald, J. M., Pelletier, E., Delmont, T. O. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.23.727376</dc:identifier>
<dc:title><![CDATA[A billion-year-old bacterial machinery replicates plastid DNA and supports kleptoplastidy]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.23.720832v1?rss=1">
<title>
<![CDATA[
Growth rate dependent DNA methylation patterns along bacterial chromosomes 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.23.720832v1?rss=1
</link>
<description><![CDATA[
DNA methylation plays critical roles in gene regulation in bacteria, from regulating essential processes like the cell cycle to phenotypes of practical interest like pathogenicity and motility. Synthetic manipulation of global methylation levels has broad impacts on cellular physiology, changing expression patterns of hundreds of genes. However, whether or how environmental variation in natural settings similarly impacts DNA methylation patterns has been unclear. In this work, using the alphaproteobacteria Methylobacterium extorquens and Caulobacter crescentus as model systems, we discover the methylome is highly fluid in response to environmental variation, with different environments leading to distinct patterns of increased or decreased methylation levels along the chromosome. Despite a heterogeneous effect of different environments on methylation patterns, we find a general principle where the dependence of methylation states on position in the genome decreases in proportion to growth rate. A simple model that considers the methylation state through different phases of the cell cycle as a function of distance from an origin provides a framework to interpret the effects of different stressors upon the observed environmental responsiveness of the methylation patterns. Our work highlights how sequencing data alone can shed light on important aspects of microbial physiology.
]]></description>
<dc:creator><![CDATA[ Mall, A., Abbaspour, M. H., Mathes, D. J., Udekwu, K. I., Marx, C. J. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.23.720832</dc:identifier>
<dc:title><![CDATA[Growth rate dependent DNA methylation patterns along bacterial chromosomes]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.727595v1?rss=1">
<title>
<![CDATA[
Environmental context reveals a conditional role of the Tol-Pal system in envelope organization in Acinetobacter baumannii 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.727595v1?rss=1
</link>
<description><![CDATA[
Gram-negative bacteria must coordinate remodeling of the peptidoglycan cell wall with invagination of the outer membrane to preserve envelope integrity during growth and division. The conserved Tol-Pal system has been implicated in coordinating these processes, yet its physiological contribution to envelope organization remains unclear and may depend on environmental context. Here, we examined the role of Tol-Pal in coordinating envelope remodeling in Acinetobacter baumannii across distinct growth environments. Loss of Tol-Pal did not cause a major population growth defect, and septal peptidoglycan incorporation remained largely preserved under standard laboratory growth conditions. In contrast, under specific environmental conditions-including nutrient-rich media, altered osmotic conditions, and host-like environments-Tol-Pal deficiency disrupted the spatial organization of cell division and cell morphology. Tol-Pal mutants also exhibited modest but reproducible reductions in outer membrane barrier robustness and decreased fitness in environmental and host-associated contexts. Together, these findings demonstrate that Tol-Pal is not an essential component of the core division machinery but instead contributes to the coordinated organization of the Gram-negative envelope under conditions that impose additional physiological demands. More broadly, our results highlight how environmental context can reveal conditional roles for conserved envelope systems that are not apparent during standard laboratory growth.
]]></description>
<dc:creator><![CDATA[ Olea-Ozuna, R. J., Furlan, B., Tiwari, S., Gong, H., Hunt-Serracin, A. C., Whalen, M., Massidda, O., Dillon, N. A., Boll, J. M. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.727595</dc:identifier>
<dc:title><![CDATA[Environmental context reveals a conditional role of the Tol-Pal system in envelope organization in Acinetobacter baumannii]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.23.727409v1?rss=1">
<title>
<![CDATA[
Genomic Decoding of Specialized Aromatic Hydrocarbon Degradation in Mangrove-Derived Gordonia sp. B7 2 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.23.727409v1?rss=1
</link>
<description><![CDATA[
Petroleum pollution has increased worldwide, driving the search for microorganisms with efficient hydrocarbon-degrading capabilities. Here, we report a novel bacterium, Gordonia sp. B7-2, isolated from mangrove sediments in Hainan, China. Phylogenetic analysis based on the 16S rRNA gene and whole-genome sequences, together with digital DNA?DNA hybridization and average nucleotide identity values, supported its classification as a new species within the genus Gordonia. The complete genome of strain B7-2 consists of a single circular chromosome of 5.39 Mb with a G+C content of 65.99%, and encodes 4,887 protein-coding genes. Genomic annotation revealed a complete pathway for aromatic hydrocarbon degradation, including genes encoding protocatechuate 3,4-dioxygenase and biphenyl-2,3-diol 1,2-dioxygenase, whereas genes involved in the initial oxidation of alkanes were absent. Consistent with these genomic predictions, strain B7-2 degraded 64.33% of crude oil (300 mg/L) within 28 days, with rapid degradation during the initial 14 days, followed by a slower phase thereafter, reflecting the dynamics of complex hydrocarbon mixtures. Together, these results demonstrate that strain B7-2 is specialized for the degradation of aromatic hydrocarbons and highlight its potential for targeted petroleum bioremediation.
]]></description>
<dc:creator><![CDATA[ Jiang, F., Shi, H., Lu, M., Zhao, Z., Xu, X., Feng, H. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.23.727409</dc:identifier>
<dc:title><![CDATA[Genomic Decoding of Specialized Aromatic Hydrocarbon Degradation in Mangrove-Derived Gordonia sp. B7 2]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.24.727467v1?rss=1">
<title>
<![CDATA[
Diabetes and Immunosuppression Drive Distinct Patterns of Candidozyma auris Skin Colonization and Dissemination in Mice 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.24.727467v1?rss=1
</link>
<description><![CDATA[
Candidozyma auris is an emerging, multidrug-resistant (MDR) fungal pathogen that persistently colonizes human skin and disproportionately causes invasive infections in patients with metabolic or immune dysfunction. Despite strong epidemiological links to diabetes and immunosuppression, how these host conditions shape skin colonization, immune defense, and dissemination remain poorly defined. Here, we establish complementary murine model of C. auris skin colonization under immunocompetent, immunosuppressed, and diabetic ketoacidosis (DKA) conditions. DKA mice exhibited significantly increased skin fungal burden, impaired clearance, and frequent systemic dissemination. Notably, DKA permitted dissemination despite preserved granulocyte and neutrophil recruitment to the skin, indicating a functional rather than quantitative defect in innate immunity. Consistent with this, phagocytes from DKA mice displayed impaired antifungal activity characterized by reduced phagocytosis and killing despite elevated reactive oxygen species production. Hyperglycemic and ketone-rich conditions (BHB) remodel the C. auris cell wall, reducing mannan, increasing chitin, and upregulating adhesins, thereby enhancing adhesion and inflammatory activation while impairing neutrophil killing. Together, these findings reveal host metabolic dysfunction as a primary driver of persistent C. auris skin colonization and dissemination, identify qualitative defects in innate antifungal immunity as a key determinant of invasive risk, and highlight metabolic condition as a critical target for infection prevention strategies.
]]></description>
<dc:creator><![CDATA[ Gupta, K. D., Quintanilla, D., Youssef, E. G., Gupta, K., Ibrahim, A. S., Singh, S. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.24.727467</dc:identifier>
<dc:title><![CDATA[Diabetes and Immunosuppression Drive Distinct Patterns of Candidozyma auris Skin Colonization and Dissemination in Mice]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.727636v1?rss=1">
<title>
<![CDATA[
Prophage and metabolic determinants of Staphylococcus aureus survival to vancomycin identified via TraDIS screening 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.727636v1?rss=1
</link>
<description><![CDATA[
Reduced vancomycin susceptibility phenotypes in Staphylococcus aureus contribute to treatment failure, yet the genetic determinants of survival under inhibitory vancomycin exposure remain incompletely defined. We performed transposon directed insertion-site sequencing (TraDIS) on a methicillin resistant S. aureus (MRSA) ST398 mutant library following exposure to vancomycin at its minimum inhibitory concentration, identifying 52 genes whose disruption was associated with loss of population survival at inhibitory drug concentrations. Prophage associated loci were the largest functional group, spanning predicted structural and regulatory genes as well as multiple conserved hypothetical proteins. Targeted testing of defined transposon mutants in a USA300 background confirmed that disruption of selected loci impaired growth under vancomycin exposure. Our results highlight the contribution of diverse physiological processes, including metabolism, stress responses, and a prominent role for prophage-associated functions, rather than discrete resistance pathways. Together, these findings indicate that vancomycin tolerance is shaped by the general physiological state of the bacterial cell, including metabolic capacity and stress adaptation.
]]></description>
<dc:creator><![CDATA[ Zborowsky, S., Lapinska, U., O'Neill, P., Farbos, A., Jeffries, A., Ba, X., Holmes, M. A., Laabei, M., Zhang, B., Blaskovich, M. A. T., Grant, A. J., Pagliara, S. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.727636</dc:identifier>
<dc:title><![CDATA[Prophage and metabolic determinants of Staphylococcus aureus survival to vancomycin identified via TraDIS screening]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.727712v1?rss=1">
<title>
<![CDATA[
Microbial cross-feeding interactions reshape evolutionary trajectories of consumers by preserving motility. 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.727712v1?rss=1
</link>
<description><![CDATA[
Cross-feeding interactions, in which a producer species release by-products that serve as resources for a consumer species, play an important role in shaping microbial community diversity. Producers create opportunities for consumers by supplying high-energy resources that are often scarce in the environment. However, they also exert strong top-down effects by releasing metabolites in pulses and generating spatial gradients of resource availability. How these spatiotemporal constraints shape consumer evolution remains poorly understood. To address this question, we used a two-species cross-feeding system in which Acinetobacter johnsonii excretes benzoate (a by-product of benzyl alcohol oxidation) into the external environment where it is consumed by Pseudomonas putida. To assess how the origin of benzoate (externally supplied or produced by cross-feeding) shapes consumer evolution, we evolved P. putida for 200 generations in monoculture or in co-culture with A. johnsonii. Populations evolved in monoculture exhibited improved growth relative to the ancestor, whereas populations evolved under cross-feeding showed little to no growth improvement. Whole-genome sequencing revealed pervasive loss-of-function mutations in flagellar genes among populations evolved in monoculture, but not under cross-feeding conditions. High-throughput imaging assays showed that populations evolved under cross-feeding not only maintained but also enhanced functional motility. Competition experiments with single mutants revealed context-dependent fitness effects: loss-of-function mutations were highly beneficial when benzoate was externally supplied but deleterious when benzoate was supplied by A. johnsonii, highlighting the importance of motility in cross-feeding interactions. Together, our results show that resource origin fundamentally reshapes selective pressures and alters evolutionary outcomes in microbial communities.
]]></description>
<dc:creator><![CDATA[ Rosazza, T., Al-Tameemi, Z., Rodriguez-Verdugo, A. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.727712</dc:identifier>
<dc:title><![CDATA[Microbial cross-feeding interactions reshape evolutionary trajectories of consumers by preserving motility.]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.727648v1?rss=1">
<title>
<![CDATA[
Early-life canine gut microbiome maturation follows a shared age-diet trajectory within persistent host-specific structure 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.727648v1?rss=1
</link>
<description><![CDATA[
Early-life gut microbiome maturation remains poorly resolved in dogs. We analyzed 146 fecal samples from 19 Pumi puppies across four dietary stages using paired shotgun metagenomics and Oxford Nanopore full-length 16S sequencing. Bacterial communities shifted from Escherichia-rich facultative assemblages during breastfeeding to anaerobe-rich communities after the transition to solid food, with the strongest compositional change occurring during dietary diversification. Functional profiles changed most strongly at the start of complementary feeding, while viral profiles showed increasing phage richness and stage-dependent predicted phage-host associations. Despite this shared dietary trajectory, host identity explained a substantial fraction of microbiome variation and produced persistent dog-specific abundance patterns. Long-read 16S profiles recovered the main developmental signal despite platform-dependent taxonomic bias, and 16S-based functional inference captured pathway-level contrasts concordant with matched metagenomes. These results identify early-life canine gut microbiome maturation as an age-diet-associated but host-constrained ecological process involving coordinated bacterial, viral, and functional restructuring.
]]></description>
<dc:creator><![CDATA[ Jaray, T., Gulyas, G., Asaduzzaman, M., Dormo, A., Csabai, Z., Kakuk, B., Boldogkoi, Z., Tombacz, D. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.727648</dc:identifier>
<dc:title><![CDATA[Early-life canine gut microbiome maturation follows a shared age-diet trajectory within persistent host-specific structure]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.727589v1?rss=1">
<title>
<![CDATA[
Genetic profiling via a novel PCR-RFLP method enabled identification of four genera of anaerobic gut fungi isolated from nyala, giraffe, and zebra hosts 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.727589v1?rss=1
</link>
<description><![CDATA[
Herbivore gut microbiomes may contain a diversity of anaerobic gut fungi (AGF, phylum Neocallimastigomycota), important for fibre degradation. To perform functional studies and elucidate niches of different AGF species, representative fungal isolates must be obtained into axenic culture, which is a resource-intensive process. Here we leverage the integration of morphological and functional assessments of AGF isolates with a newly developed PCR-RFLP strategy, to distinguish and identify isolates of interest from faecal samples from zoo-housed animals. In silico prediction of PCR-RFLP profiles of cultured genera, followed by experimental validation, confirmed that LSU-based PCR-RFLP with AluI and Hyp188I digestion was effective in identification of fungi of distinct genera. Together our workflow resulted in isolation of a so far uncultured Piromyces (NY08) species and Neocallimastix cameroonii from nyala samples, as well as Feramyces austinii from giraffe and Khoyollomyces ramosus from zebra. Amplicon sequencing confirmed that these species dominated AGF communities in their hosts, likely benefiting isolation success, and we identified enrichment conditions which also affected cultivability. The workflow developed here aids efficient AGF isolations, which are instrumental in expanding opportunities for functional studies that provide insight into the physiology and ecology of these fungi and help realise applications in white and green biotechnology.
]]></description>
<dc:creator><![CDATA[ Edge, L., Duan, P., Kerangart, S., Buckner, A. M., van Munster, J. M. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.727589</dc:identifier>
<dc:title><![CDATA[Genetic profiling via a novel PCR-RFLP method enabled identification of four genera of anaerobic gut fungi isolated from nyala, giraffe, and zebra hosts]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.23.727408v1?rss=1">
<title>
<![CDATA[
OxyR regulates the oxidative stress response in Zymomonas mobilis during oxic growth and anoxic biofuel fermentation 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.23.727408v1?rss=1
</link>
<description><![CDATA[
The bacterium Zymomonas mobilis is widely studied for its potential as an industrial biofuel producer. Anoxic fermentation by Z. mobilis in lignocellulosic hydrolysate can generate bioethanol from renewable plant biomass. In this study, we deleted a gene from the Z. mobilis genome encoding a homolog of OxyR, a transcription factor that activates an oxidative stress response in bacteria to reduce reactive oxygen species (ROS). Deletion of this transcription factor inhibited growth of Z. mobilis in oxic, but not anoxic, conditions in laboratory media. A ROS probe revealed that the oxyR response is required to reduce intracellular ROS during oxic growth. Importantly for biofuel production, the absence of oxyR inhibited growth and delayed ethanol production during anoxic hydrolysate fermentation. To determine the source of oxidative stress in hydrolysate, we grew {Delta}oxyR in a synthetic hydrolysate containing known inhibitors found in hydrolysate. There was no growth defect in {Delta}oxyR in the synthetic hydrolysate, indicating that known inhibitory compounds are not the source of anoxic oxidative stress. We determined that Ammonia-Fiber Expansion (AFEX) switchgrass hydrolysate contains significant peroxide concentrations. Addition of catalase to hydrolysate improves growth of both {Delta}oxyR and wild-type Z. mobilis in hydrolysate. This study uncovers an important source of stress to Z. mobilis during biofuel fermentation.
]]></description>
<dc:creator><![CDATA[ Boismer, E., Felczak, M. M., Myers, K. S., TerAvest, M. A. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.23.727408</dc:identifier>
<dc:title><![CDATA[OxyR regulates the oxidative stress response in Zymomonas mobilis during oxic growth and anoxic biofuel fermentation]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.727578v1?rss=1">
<title>
<![CDATA[
Genomic Diagnostics for Drug-Resistant Mycobacterium tuberculosis: Computational Prediction of Antimicrobial Resistance 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.727578v1?rss=1
</link>
<description><![CDATA[
Tuberculosis remains a leading cause of infectious disease mortality, and the continued emergence of drug-resistant Mycobacterium tuberculosis strains threatens the effectiveness of standard treatment regimens. Culture-based antibiotic susceptibility testing remains the clinical reference standard for resistance determination but typically requires six to eight weeks, delaying initiation of optimized therapy for patients with drug-resistant disease. Whole-genome sequencing-based approaches provide a rapid alternative for predicting antimicrobial resistance directly from genomic data and are increasingly being incorporated into diagnostic workflows. This survey reviews computational approaches for genomic resistance prediction in Mycobacterium tuberculosis, focusing on two major classes of methods: catalog-based tools that identify established resistance-conferring variants, and de novo machine learning approaches that infer resistance from genome-wide sequence features. We examine the strengths and limitations of these approaches with respect to interpretability, scalability, computational requirements, and concordance with phenotypic testing. We further discuss emerging directions in quantitative minimum inhibitory concentration prediction, challenges in pyrazinamide susceptibility testing, and the limited availability of resistant isolates for newer and repurposed drugs used in multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis treatment regimens. Continued expansion of paired phenotypic and genomic datasets, standardized minimum inhibitory concentration testing protocols, and rigorous lineage-aware evaluation frameworks will be essential for improving the clinical reliability and global deployment of genomic resistance prediction for tuberculosis diagnostics.
]]></description>
<dc:creator><![CDATA[ Serajian, M., Han, Y., Boucher, C. A. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.727578</dc:identifier>
<dc:title><![CDATA[Genomic Diagnostics for Drug-Resistant Mycobacterium tuberculosis: Computational Prediction of Antimicrobial Resistance]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.727575v1?rss=1">
<title>
<![CDATA[
Cryptococcus gattii responds to mycobacterial exposure through coordinated remodelling of population dynamics and cell surface architecture, enhancing pulmonary persistence in a co-infection model 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.727575v1?rss=1
</link>
<description><![CDATA[
Cryptococcus neoformans and Cryptococcus gattii are major causes of fungal pneumonia and meningitis, frequently co-occurring with Mycobacterium tuberculosis in endemic regions, where co-infection is associated with increased mortality. Yet, how Cryptococcus adapts to mycobacterial co-presence within the lung remains poorly understood. Here, we show that mycobacterial cues trigger a conserved adaptive programme in C. gattii, mirroring responses previously observed in C. neoformans. Increasing exposure to mycobacteria drives cell and capsule enlargement and promotes titan cell formation, accompanied by dose-dependent remodelling of chitin and chitosan. Importantly, in vivo exposure to heat-killed mycobacteria increases C. gattii pulmonary burden, linking structural remodelling to enhanced persistence. These findings identify mycobacterial co-presence as a driver of fungal phenotypic plasticity and reveal pathogen-pathogen interactions as critical regulators of disease outcome, highlighting a previously unrecognised axis of co-infection relevant to C. gattii pathogenesis and therapeutic strategy.
]]></description>
<dc:creator><![CDATA[ Irere, H., San, Z. N., Mukaremera, L., Dambuza, I. M. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.727575</dc:identifier>
<dc:title><![CDATA[Cryptococcus gattii responds to mycobacterial exposure through coordinated remodelling of population dynamics and cell surface architecture, enhancing pulmonary persistence in a co-infection model]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.726231v1?rss=1">
<title>
<![CDATA[
Structure of an eDNA-scaffolded Scp-like protease filament from Streptococcus sanguinis 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.726231v1?rss=1
</link>
<description><![CDATA[
C5a peptidases are surface-associated serine proteases that enable pathogenic streptococci to evade innate immunity by degrading neutrophil chemoattractants. These enzymes are canonically anchored to the bacterial cell wall via an LPXTG motif and have only been characterized as monomers. Here, we report the cryo-EM structure of an unexpected supramolecular assembly from Streptococcus sanguinis, in which an Streptococcal C5a peptidase-like (ScpH) oligomerizes into an extended filament scaffolded on extracellular DNA (eDNA). The 3.1 A resolution structure reveals that this protease forms interlocked dimers through reciprocal contacts between the Ig and protease-Fn domains, and that these dimers propagate into a double-rowed filament via three additional inter-protomer interfaces. The central eDNA strand is engaged by an electropositive cleft formed by the C-terminal FIVAR3 domain and the DNA-binding tail, which replace the LPXTG anchor found in characterized orthologs. AlphaFold3 predictions indicate that both dimerization and eDNA binding are conserved across a subfamily of streptococcal species that are prominent oral colonizers and eDNA producers. The catalytic triad is structurally intact and a co-purified peptide occupies the active site, although proteolytic activity remains to be demonstrated. This structure reveals a previously unknown mechanism of biofilm functionalization in which a putative immune evasion protease is assembled directly onto eDNA, transforming a passive structural component of the biofilm matrix into a potential catalytic platform.
]]></description>
<dc:creator><![CDATA[ Fronzes, R., Anger, R., Pieulle, L., Vallart, A., Baudeau, L., Pelicic, V. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.726231</dc:identifier>
<dc:title><![CDATA[Structure of an eDNA-scaffolded Scp-like protease filament from Streptococcus sanguinis]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.727494v1?rss=1">
<title>
<![CDATA[
Effects of sulfide on the activity of the ammonia-oxidizing archaeon Nitrosopumilus maritimus SCM1 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.727494v1?rss=1
</link>
<description><![CDATA[
Ammonia-oxidizing archaea (AOA) are frequently found in oxygen-depleted marine environments with permanent or temporal presence of sulfide (HS-). However, it remains unexplored how sulfide affects the activity of ammonia-oxidizing archaea. We studied the capability of Nitrosopumilus maritimus SCM1 to oxidize ammonia when exposed to HS-. Ammonia oxidation remained active even after exposure to sulfidic spikes in the lower micromolar range, albeit at reduced rates compared to the absence of HS-. However, 90 {micro}M HS- completely inhibited ammonia oxidation. We found no evidence of NO-dismutation under oxygen depletion and presence of HS- (20 {micro}M): the formation of oxygen, nitrous oxide and dinitrogen did not occur. All in all, we confirmed ammonia oxidation in N. maritimus SCM1 under oxic conditions after sulfide additions, but no evidence of NO-dismutation under sulfidic conditions. Our findings suggest that AOA can recover ammonia-oxidation activity after oxygen re-exposure in regions with periodic sulfide accumulation. However, in permanently sulfidic areas, ammonia oxidation recovery seems unlikely, as NO-dismutation does not appear to be a viable mechanism.
]]></description>
<dc:creator><![CDATA[ Garcia Otero, P., Kraft, B. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.727494</dc:identifier>
<dc:title><![CDATA[Effects of sulfide on the activity of the ammonia-oxidizing archaeon Nitrosopumilus maritimus SCM1]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.25.727473v1?rss=1">
<title>
<![CDATA[
Deciphering the Acetaldehyde Signaling Network Underlying Bacterial Escape from Protozoan Predators 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.25.727473v1?rss=1
</link>
<description><![CDATA[
Entamoeba histolytica (Eh) is a formidable intestinal pathogen, yet the ecological principles governing its invasion of the gut microbiome remain elusive. Upon colonization, Eh encounters resident bacteria typically sequestered within aggregates and biofilms. While Eh utilizes cysteine proteinases to degrade biofilm matrices and access bacterial prey, the strategies bacteria employ to sense and evade this predation are largely unknown. Here, we identify a metabolic signalling axis that allows the probiotic bacterium Bacillus subtilis to perceive and respond to predatory Eh. In the absence of mitochondria, Eh relies on fermentative glycolysis, using alcohol dehydrogenase to produce distinct metabolic byproducts. Using quantitative proteomics and single-cell imaging, we demonstrate that B. subtilis detects the Eh-derived metabolite acetaldehyde as a proxy for predator presence. By mapping the acetaldehyde-responsive regulatory network, we show how this metabolic input is transduced to control the motility machinery, while our data suggest that the broader predatory secretome acts as a multi-modal signal influencing multiple bacterial physiological programs. This chemical cue triggers a rapid phenotypic switch in B. subtilis, driving a transition towards a motile, planktonic "flight" response. Our findings reveal that commensal bacteria exploit the unique metabolic signature of anaerobic parasites to coordinate defensive behaviours, highlighting how inter-kingdom signalling shapes microbiome architecture during infection.
]]></description>
<dc:creator><![CDATA[ Murugan, P. A., Mahapatra, S., Liberty, A., Trebicz-Geffen, M., Ankri, S., Kolodkin-Gal, I. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.25.727473</dc:identifier>
<dc:title><![CDATA[Deciphering the Acetaldehyde Signaling Network Underlying Bacterial Escape from Protozoan Predators]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
<item rdf:about="https://www.biorxiv.org/content/10.64898/2026.05.22.727170v1?rss=1">
<title>
<![CDATA[
The Cu-induced ScsD reductase is a membrane-bound redox partner of ScsB in the Salmonella envelope 
]]>
</title>
<link>
https://www.biorxiv.org/content/10.64898/2026.05.22.727170v1?rss=1
</link>
<description><![CDATA[
The intracellular environment Salmonella confronts during infection is characterized by multiple redox stressors including reactive oxygen species (ROS) and copper (Cu) ions. Under these conditions, alternative systems of thiol oxidoreductases such as the Cu induced Scs system are required to protect and repair periplasmic proteins. The scsABCD operon encodes three Dsb-like enzymes, ScsB, ScsC, and ScsD, and an accessory protein, ScsA. These proteins are required both for Cu resistance and H2O2 tolerance. ScsB and ScsC function analogously to the canonical DsbD/DsbC redox pair of thiol oxidoreductases. The absence of ScsC was shown to affect the folding/activity of periplasmic proteins involved in amino acid transport and redox homeostasis. Here, we focus in ScsD, the least characterized member of this system. Upon Cu-induced expression, ScsD localizes to the inner membrane, enabling its predicted C-terminal Dsb-like domain to be exposed to the periplasm. Functional analysis indicates that ScsD exists in a reduced state in the Salmonella envelope and serves as a redox partner of ScsB. ScsD exhibits in vivo disulfide reductase activity and restores a deficient disulfide reduction pathway in Salmonella. Similar to ScsC and ScsB, ScsD binds Cu(I) via the Cys residues of its Dsb-like domain; however, this metal interaction appears to lack relevance in Cu detoxification as no impact on intracellular Cu levels was observed. Our results define ScsD as a specialized membrane-bound thiol-disulfide reductase in the Salmonella envelope and highlight the versatility of the Scs system in maintaining periplasmic proteostasis when canonical pathways are compromised by host-imposed Cu stress.

ImportanceCopper is a key component of the innate immune system, serving as a primary defense against pathogens like Salmonella. Copper overload targets the bacterial envelope, specifically attacking protein sulfhydryl groups. This causes protein misfolding and inactivation, disrupting essential processes like metabolism, transport and virulence. To survive this stress and restore thiol homeostasis, Salmonella utilizes the scsABCD operon. While the ScsB-ScsC redox pair is well-documented and some protein substrates identified, the role of ScsD remains undefined. This work characterizes ScsD as an inner-membrane-anchored thiol reductase and a new redox partner for ScsB. The ScsD/ScsB pair expands the bacteriums protein quality control capacity, allowing Salmonella to maintain envelope homeostasis within the hostile, copper-rich environment of the host.
]]></description>
<dc:creator><![CDATA[ Mendez, A. A. E., Reinero, J. J., Zhao, Z., Bertonati, B., Argüello, J. M., Soncini, F. C., Checa, S. K. ]]></dc:creator>
<dc:date>2026-05-25</dc:date>
<dc:identifier>doi:10.64898/2026.05.22.727170</dc:identifier>
<dc:title><![CDATA[The Cu-induced ScsD reductase is a membrane-bound redox partner of ScsB in the Salmonella envelope]]></dc:title>
<dc:publisher>Cold Spring Harbor Laboratory</dc:publisher>
<prism:publicationDate>2026-05-25</prism:publicationDate>
<prism:section></prism:section>
</item>
</rdf:RDF>
