Key limitations of GM modulation in influencing lung diseases.

#MicrobiologyMonday: By shaping immune responses and producing metabolites, the gut‑lung axis offers possibilities for microbiome‑based therapies for respiratory diseases—though more research is needed to turn promise into practice. #IAIJournal: asm.social/2RZ

Pregnancy-associated shifts in maternal microbiota across multiple body sites can signal to the placenta, influencing its function and fetal development.

Maternal microbial ecosystems are key in shaping reproductive physiology and pregnancy outcomes. While the gut microbiota has been extensively studied, the roles of microbes in other body regions are less clear. This #IAIJournal review provides insights: asm.social/2OQ

Prominent programmed cell death pathways include the major sources of extracellular metabolite release. Bacteria/metabolites that can exploit/modulate these pathways are given in red with arrows facing away, lines indicating inhibition and arrows pointing towards bacteria indicate utilization. Table 1 provides further details and references. DAMP; danger-associated molecular pattern. PAMP; pathogen-associated molecular pattern. MOMP; mitochondrial outer membrane permeabilization. AMPs; antimicrobial peptides. GSH; glutathione. Panx1; Pannexin-1 membrane channel.

#MicrobiologyMonday: Cells can die in a lot of ways. Bacteria modulate and are modulated by host cell death. Insights on the mechanisms underlying these interactions can offer potential routes to control microbiota-associated diseases. #IAIJournal: asm.social/2MJ

Intracellular clusters of E. faecalis within neutrophils in the murine wound bed at 24 h p.i. Mice were wounded and infected with 106 CFU of E. faecalis OG1RF.

Enterococcus faecalis is one of the most commonly isolated pathogens from chronic wounds. In #IAIJournal, researchers report that the bacterium survives and replicates intracellularly within neutrophils, which may contribute to its ability to persist. asm.social/2KO

Per decade increase of antimicrobial resistance genes among B. fragilis strains. The percentage of strains with the indicated antimicrobial resistance gene, as identified by whole genome sequencing, is shown by decade of isolation: 1970s or earlier (n = 6), 1980s (n = 37), 1990s (n = 9), 2000s (n = 28), 2010s, (n = 182), and 2020s (n = 132). Antimicrobial resistance genes are displayed on the X axis along with antibiotic class, and decade of isolation on the Y axis.

Despite its beneficial roles in the gut, Bacteroides fragilis is also the most commonly isolated anaerobe in clinical infections. This #IAIJournal study suggests AMR is widespread among intestinal and extra-intestinal B. fragilis clinical isolates: asm.social/2Ik

Effect of EFs-Lc application prior to GBS infection. (A) Schematic depicts the experimental design where VK2/E6E7 transwells were treated with EFs-Lc, blank EFs, free L. crispatus (Lc), or mock treatment (PBS) for 24 hours before GBS or mock (PBS) infection. Created in BioRender. Doster, R. (n.d.) https://BioRender.com/judciyo (B) SEM images of VK2/E6E7 transwells following treatments with EFs, EFs-Lc, L. crispatus (Lc), or mock treatment alone (left) or followed by GBS infection (right). Yellow measurement bar represents 10 m, and yellow triangles denote areas of colocalization of GBS and L. crispatus. (C, D) Quantification of L. crispatus (C) and GBS (D) from the apical transwell chamber after treatment and 24 hours of GBS infection. (E, F) Quantification of IL-8 (E) and IL-1RA (F) from transwell basal supernatants. Bars represent the mean of four biological replicates ±SEM.

Vaginal colonization with Lactobacilli protect against group B Streptococcus (GBS). Notably, delivering L. crispatus to vaginal epithelial cells via electrospun nanofibers modulates inflammatory signaling during established GBS infection. #IAIJournal: asm.social/2AG

Drivers of microbial community dynamics in host-associated environments. Environmental factors, such as nutrient availability, oxygen, pH, and tissue topography, collectively shape the composition and microbiome metabolism of microbial communities within the host. The central panel represents a snapshot of a microbial community at a given time. The right panel illustrates community dynamics, including temporal shifts in microbial populations and interactions between community members that drive community composition and the microbiome metabolism. Microbial interactions are categorized as cooperative (blue) or competitive (red), reflecting the ecological forces that influence microbial stability, succession, and pathogenicity. This conceptual map emphasizes the context-dependent nature of microbial behavior and the importance of studying communities within physiologically relevant environments. Created in BioRender. Arriaga, S. (2025)

Microbes rarely exist alone; instead, they live in dynamic communities. In #IAIJournal, researchers discuss the interplay between the host environment & microbiome metabolism & the impacts on disease progression in host-associated polymicrobial communities. asm.social/2yf

Type I IFNs contribute to PD-L1 upregulation during C. trachomatis infection in vivo.

Chlamydia trachomatis infection triggers production and secretion of type I IFNs that induce PD-L1 upregulation, which may contribute to the intracellular bacterium's evasion of adaptive immune responses. Learn more in #IAIJournal: asm.social/2kS

Electron microscopy of P. aeruginosa after treatment with sphingosine. P. aeruginosa ATCC 27853 were treated with 20 µM sphingosine (SPH) for 10 min or 30 min or left untreated, fixed, embedded, and analyzed by electron microscopy. A higher concentration of sphingosine was used because 108 CFU P. aeruginosa were used in these experiments to obtain a pellet, which we were able to process. Shown is each a representative picture from at least 50 visualized cells. The arrows in the images in the upper row indicate some of the membrane blebs, and the arrows in the image in the lower row indicate typical membrane rolls. Scale bar sizes in the images: left column (both images) and middle and right column (upper images), each 200 nm; middle column (lower image), 50 nm; right column (lower image), 100 nm.

Sphingosine, found on epithelial cells but undetectable in cystic fibrosis patients, kills P. aeruginosa via degradation of cardiolipin, leading to severe membrane changes; mammalian cells lack membranous cardiolipin & remain unharmed. #IAIJournal: journals.asm.org/doi/10.1128/...

Quantification of AafA expression and biofilm formation in a panel of AafA variants with single amino acid substitutions.

Enteroaggregative Escherichia coli (EAEC) adherence is mediated by aggregative adherence fimbriae (AAFs). Research in #IAIJournal provides insights into the structural features determining AAF/II binding to mucin, sialic acid & human intestinal cells. asm.social/2jG

Prolonged infection of Calu-3 cells with P. aeruginosa in the presence of tobramycin.

Using a reproducible human cell-based airway infection model, researchers illustrate the complex scenario of prolonged airway colonization, emphasizing the remarkable adaptability of P. aeruginosa to challenging infection environments. #IAIJournal: journals.asm.org/doi/10.1128/...

Isolation and characterization of Salmonella strains from wastewater samples. (A) A total of 120 Salmonella isolates were collected from qPCR-invA-positive wastewater samples in Gainesville. The isolation process involved an initial enrichment phase in TSB, followed by selection on MSRV plates and further biochemical confirmation on XLD plates. Serotyping and sequencing were performed by the State of Florida Department of Health using SeqSero2, with successful serotyping of 21 isolates. (B) Phylogenetic analysis indicating the taxonomy and evolutionary distance between the selected Salmonella isolates.

Scientists evaluated the efficacy of a small extracellular vesicle-based vaccine against circulating strains of Salmonella isolated from wastewater, providing a strategy for developing effective preventative measures against infection. #IAIJournal: asm.social/2fW

The morphogenetic PBP2 is required for SPI-1 T3SS activity. (A) Coomassie staining of whole cell-associated proteins and secreted proteins of the indicated strains grown in LB pH 5.8 to stationary phase. The position of the SPI-1 proteins SipA, SipB, SipC, and SipD is indicated, as well as flagellins FliC and FljB. Positions and size (in kDa) of molecular weight markers are shown. (B) Levels of SipC detected by Western blotting in whole cell-associated and secreted protein extracts of the indicated isogenic mutants. The volumes loaded of whole cell and supernatant extracts in panels (A) and (B) correspond to 2.75 × 107 and 2.75 × 109 bacteria, respectively. Coomassie staining of the PVDF membrane used in the Western blot is shown as loading control; (C) Levels of the SPI-1 structural protein PrgK in mutants lacking PBP2 or PBP2SAL grown overnight in LB pH 5.8. A null prgK mutant was run in parallel as negative control. Asterisks denote non-specific bands; (D) Secretion of SipC is not altered in the absence of the major PG synthases PBP1A or PBP1B. The Coomassie staining of the same samples run on a gel is shown as loading control; (E) Motility assay of S. Typhimurium mutants lacking morphogenetic PBPs. Shown are the motility halos observed after 6 h of growth in semi-solid motility medium pH 4.6 (see Materials and Methods). Data are representative of two biological replicates.

In Salmonella, penicillin-binding protein (PBP) 2 is required for proper function of the pathogenicity island-1 (SPI-1) T3SS but is dispensable for motility, whereas the lack of any of the morphogenetic PBPs increases SPI-2 T3SS activity. #IAIJournal: asm.social/2fr

Bioluminescence imaging of B. burgdorferi in living mice. Groups of C3H mice were injected intradermally with OY444 (WT), the bb0689 mutant OY470 (Mut), or the complemented strain OY601 (Com) at a dose of 10,000 spirochetes per mouse. At various time points post infection, mice were injected with D-luciferin and analyzed using a Perkin Elmer IVIS imaging system. To obtain a global assessment of di

Expression of bb0689, an RpoS-regulated gene encoding an outer surface lipoprotein with unknown function, is a key contributor to the optimal infection of Borrelia burgdorferi in animals. Learn more in #IAIJournal: journals.asm.org/doi/10.1128/...