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1. Genome sequence of Pyrococcus woesei DSM 3773 ^T —an anaerobic, hyperthermophilic archaeum from heated marine solfataras

   https://doi.org/10.1128/mra.00528-25  

   Drew, Suzie; St_John, Emily; Bartlett, Michael (October 2025, Microbiology Resource Announcements)

   Stewart, Frank J (Ed.)

   ABSTRACT Here, we report the circularized complete genome ofPyrococcus woeseiDSM 3773^T(1,856,505 bp, G + C 40.7%). This genome contains 1,955 protein-coding regions and 46 tRNAs.P. woeseiis the closest known relative to the archaeal model organismP. furiosus. 

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2. Draft genome sequence of Paenibacillus turicensis DSM 14349 ^T from cerebrospinal fluid of a patient in Switzerland

   https://doi.org/10.1128/mra.01373-25  

   Berzansky, Marion; Handojo, Mia; Pukall, Rüdiger; Göker, Markus; Woyke, Tanja; Seshadri, Rekha; Luna_Lopez, Carlos; Read, Betsy (April 2026, Microbiology Resource Announcements)

   Van_Tyne, Daria (Ed.)

   ABSTRACT We report the draft genome of the gram-positive bacteriumPaenibacillus turicensisDSM 14349^T,isolated from the cerebrospinal fluid of a male patient. The 4.8 Mbp genome encodes 4,551 genes, including 4,423 protein-coding sequences, some of which may contribute to its ability to survive in a nutrient-poor environment. 

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3. Azomycin produced by Pseudomonas has both phytotoxic and anti-oomycete activity

   https://doi.org/10.1128/jb.00292-25  

   Morales_Moreira, Zayda P; Kak, Kareena; Wei, Zi-Wang; Yanez-Ortuno, Daniela; Wang, Nicole R; Hedges, Jason B; Chen, Melissa Y; Geissmann, Quentin; Zhang, Wentao; Chatterton, Syama; et al (December 2025, Journal of Bacteriology)

   O'Toole, George (Ed.)

   ABSTRACT Members of the genusPseudomonassynthesize diverse natural products that contribute to their versatility in free-living and host-associated lifestyles. Here, we characterized thein vivofunctions of the nitroimidazole antibiotic azomycin in the genusPseudomonas. We found that genes with similarity to azomycin biosynthesis genesrohPQRSTare prevalent within thePseudomonas syringaespecies complex and rarely present in thePseudomonas fluorescensspecies complex. Azomycin production was detectable in culture by biocontrol strainsPseudomonasspp. DF41 and CMR5a.Pseudomonassp. DF41 exhibited anti-oomycete activity that was lost in a∆rohPQRSTmutant. Purified azomycin was sufficient to kill the oomycete pathogensAphanomycesandPhytophthora. Although DF41 has been studied for its role in biocontrol of plant pathogens, we found that azomycin exhibited phytotoxicity againstPisum sativum(pea) plants at similar concentrations to those that inhibited oomycetes. However, consistent with its use as a biocontrol agent,Pseudomonassp. DF41 only produced azomycinin plantawhen pea plants were infected with the oomycete pathogenAphanomyces euteiches. Our findings suggest dual roles for azomycin inPseudomonas,functioning both as a biocontrol agent of oomycete pathogens, as well as a phytotoxic molecule with a potential role in plant virulence.IMPORTANCEWhile many natural products are studied for their roles in the treatment of plant or human disease, the ecological functions of natural products are understudied. We found that an antibiotic, azomycin, is produced byPseudomonasspecies and has toxicity against both plants and oomycete pathogens. Our findings suggest a complex ecological role of azomycin production byPseudomonasin both the amelioration and exacerbation of plant disease. 

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4. Hybridization capture sequencing for Vibrio spp. and associated virulence factors

   https://doi.org/10.1128/mbio.00516-25  

   Brumfield, Kyle D; Enke, Sana; Swan, Brandon K; Carrasquilla, Lakeshia; Lee, Michael D; Stern, David B; Gieser, Linn; Hasan, Nur A; Usmani, Moiz; Jutla, Antarpreet S; et al (August 2025, mBio)

   Hinton, Deborah (Ed.)

   ABSTRACT Proliferation ofVibriospp. in aquatic ecosystems is associated with climate change and, concomitantly, increased incidence of vibriosis. They are autochthonous to aquatic environments globally, but traditional metagenomic methods for detecting and typing pathogenicVibriospp. are challenged by their presence in relatively low abundance and ability to persist in a viable but nonculturable state. In the study reported here, hybridization capture sequencing (HCS) was employed to profile low-abundanceVibriospp. in environmental samples. The HCS panel targeted a family of molecular chaperones (CPN60) specific to 69Vibriospp. and 162Vibrio-specific virulence factors. This approach was evaluated in parallel with traditional whole-community shotgun sequencing in a metagenomic analysis of water and oyster samples collected from the Chesapeake Bay. In addition,Vibrio parahaemolyticusandVibrio vulnificusstrains isolated from the samples were subjected to whole-genome sequencing to determine the genetic characteristics of pathogenicVibriospp. circulating in an aquatic environment. HCS, employed to determine the incidence and characterization of specificVibriospp., yielded significantly greater metagenomic insight, notably a variety of otherVibriospp., including detection ofVibrio cholerae,Vibrio fluvialis, andVibrio aestuarianus, in addition toVibrio parahaemolyticusandVibrio vulnificus, and also important virulence factors not detectable using traditional molecular methods. Thus, pathogenicVibriospp. in aquatic ecosystems may be far more common than currently understood. It is concluded that environmental surveillance should include HCS, a valuable tool for the detection and characterization of pathogenic agents in aquatic ecosystems, notably vibrios.IMPORTANCEThe increasing prevalence of pathogenicVibriospp. in aquatic ecosystems, driven by climate change, is closely linked to a rise in cholera and vibriosis cases, emphasizing the need for improved environmental surveillance. Vibrios are naturally occurring in aquatic environments globally, but traditional metagenomic methods for detecting and typing pathogenicVibriospp. are challenged by their presence in relatively low abundance and ability to persist in a viable but nonculturable state. In the study reported here, hybridization capture sequencing was employed to profile low-abundanceVibriospp. in metagenomic samples, namely water and oysters collected from the Chesapeake Bay. This approach was evaluated in parallel with traditional whole-community shotgun sequencing and whole-genome sequencing ofVibrio parahaemolyticusandVibrio vulnificusstrains isolated from the samples. Results suggest pathogenicVibriospp. in aquatic ecosystems may be far more common than currently understood, when multiple methods are considered for environmental surveillance. 

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5. Dissecting the role of flagellar subunits in C. difficile mucosal colonization

   https://doi.org/10.1128/jb.00428-25  

   Biswas, Baishakhi; Do, Thi_Van Thanh; Perdomo, Justin G; Auchtung, Jennifer M; Piepenbrink, Kurt H (December 2025, Journal of Bacteriology)

   Champion, Patricia A (Ed.)

   ABSTRACT Clostridioides difficileis a common cause of acute gastrointestinal (GI) inflammation in mammals, which can have detrimental effects on host health.C. difficile-associated disease requires the secretion of high-molecular-weight toxins after colonization of the GI tract. The molecular mechanisms of GI colonization byC. difficileinclude potential interactions with host cells and the mucus layer formed from secreted mucin glycoproteins.C. difficileassociates with the mucus layerin vivoand will associate with both epithelial cells and mucosal surfacesin vitro. Previously, we found a substantial defect in binding to mucosal surfaces for mutants of the major flagellar subunit,fliC, while mutation of the major subunit of type IV pili,pilA1, showed increased adhesion. To elucidate the mechanisms by whichC. difficileinteracts withex vivomucosal surfaces, we have measured swimming motility, mucosal adhesion, and levels of flagellation by transmission electron microscopy for mutants of flagellar and T4P genes inC. difficileR20291. We discovered that thepilA1mutant showed increased flagellation, while decreases in flagellation were found forfliC, fliD,andflg-Δ3 OFF (a phase-locked mutant with low transcription of the F3 flagellar operon), which were associated with both low swimming motility and low adhesion to mucosal surfaces. However, the reversedflg-Δ3 ON mutant showed increased flagellation without a significant increase in adhesion. We also found that thefliCmutant was defective in binding to mucus-secreting HT-29 MTX cells, and that decreased binding was not observed for other mutants with reduced flagellation. These results imply that at least two molecular pathways contribute toC. difficilemucosal adhesion. In addition to their direct roles encoding T4P and flagellar subunits,pilA1andfliCmay contribute to regulatory networks governing other proteins relevant to mucosal adhesion.IMPORTANCEIn the context of previous work onClostridioides difficilehost adhesion by our groups and others, our results suggest that (i) at least two mechanisms exist for mucosal adhesion byC. difficile, potentially direct adhesion by flagella and another lectin-like adhesion regulated by flagellar components; (ii) mucosal binding can also contribute toC. difficileadhesion in 2D cell culture and could explain previous defects fromfliCmutants; and (iii) levels of flagellation are largely insensitive tofliCtranscription, implying that other factors limit flagellar production and that FliC levels may be regulated independently as part of regulatory networks withinC. difficile. 

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