Diclofenac sensitizes multi-drug resistant Acinetobacter baumannii to colistin.

Acinetobacter baumannii causes life-threatening infections that are becoming difficult to treat due to increasing rates of multi-drug resistance (MDR) among clinical isolates. This has led the World Health Organization and the CDC to categorize MDR A. baumannii as a top priority for the research and development of new antibiotics.

Unraveling the role of UilS, a urea-induced acyl-homoserine lactonase that enhances fitness, interbacterial competition, and urinary tract infection.

Unlabelled: , a member of the Enterobacteriaceae family, is an opportunistic human pathogen and a frequent cause of urinary tract infections. Clinical isolates often exhibit resistance to multiple antibiotics, posing challenges for successful treatment. Understanding its pathogenic mechanisms is crucial for elucidating new potential targets to develop effective therapeutic interventions and manage infections.

A chronic murine model of pulmonary infection enabling the investigation of late virulence factors, long-term antibiotic treatments, and polymicrobial infections.

can cause prolonged infections that disproportionately affect immunocompromised populations. Our understanding of respiratory pathogenesis relies on an acute murine infection model with limited clinical relevance that employs an unnaturally high number of bacteria and requires the assessment of bacterial load at 24-36 hours post-infection. Here, we demonstrate that low intranasal inoculums in immunocompromised mice with a mutation leads to reduced inflammation, allowing for persistent infections lasting at least 3 weeks.

Screening for Genes Involved in Outer Membrane Vesicle Biogenesis in Bacteroides thetaiotaomicron.

Bacteroides spp. are prominent gut commensals that are believed to modulate the intestinal environment, in part, by producing outer membrane vesicles (OMVs). Bacteroides OMVs have been ascribed many functions in vitro, but the genetic underpinnings behind OMV biogenesis and regulation are unclear.

Identification and Characterization of the Lipoprotein -acyltransferase in .

Members of the Bacteroidota compose a large portion of the human gut microbiota, contributing to overall gut health via the degradation of various polysaccharides. This process is facilitated by lipoproteins, globular proteins anchored to the cell surface by a lipidated N-terminal cysteine. Despite their importance, lipoprotein synthesis by these bacteria is understudied.

Diclofenac sensitizes multi-drug resistant to colistin.

causes life-threatening infections that are becoming difficult to treat due to increasing rates of multi-drug resistance (MDR) among clinical isolates. This has led the World Health Organization and the CDC to categorize MDR as a top priority for the research and development of new antibiotics. Colistin is the last-resort antibiotic to treat carbapenem-resistant .

Dual membrane-spanning anti-sigma factors regulate vesiculation in .

Bacteroidota are abundant members of the human gut microbiota that shape the enteric landscape by modulating host immunity and degrading dietary- and host-derived glycans. These processes are mediated in part by uter embrane esicles (OMVs). Here, we developed a high-throughput screen to identify genes required for OMV biogenesis and its regulation in ().

The tRNA methyltransferase TrmB is critical for stress responses and pulmonary infection.

As deficiencies in tRNA modifications have been linked to human diseases such as cancer and diabetes, much research has focused on the modifications' impacts on translational regulation in eukaryotes. However, the significance of tRNA modifications in bacterial physiology remains largely unexplored. In this paper, we demonstrate that the mG tRNA methyltransferase TrmB is crucial for a top-priority pathogen, , to respond to stressors encountered during infection, including oxidative stress, low pH, and iron deprivation.

Dual Membrane-spanning Anti-Sigma Factors Regulate Vesiculation in Gut Bacteroidota.

Bacteroidota are abundant members of the human gut microbiota that shape the enteric landscape by modulating host immunity and degrading dietary- and host-derived glycans. These processes are at least partially mediated by O uter M embrane V esicles (OMVs). In this work, we developed a high-throughput screen to identify genes required for OMV biogenesis and its regulation in ( ).

Human gut bacteria tailor extracellular vesicle cargo for the breakdown of diet- and host-derived glycans.

Extracellular vesicles are produced in all three domains of life, and their biogenesis has common ancient origins in eukaryotes and archaea. Although bacterial vesicles were discovered several decades ago and multiple roles have been attributed to them, no mechanism has been established for vesicles biogenesis in bacteria. For this reason, there is a significant level of skepticism about the biological relevance of bacterial vesicles.

Replicative Acinetobacter baumannii strains interfere with phagosomal maturation by modulating the vacuolar pH.

Bacterial pneumonia is a common infection of the lower respiratory tract that can afflict patients of all ages. Multidrug-resistant strains of Acinetobacter baumannii are increasingly responsible for causing nosocomial pneumonias, thus posing an urgent threat. Alveolar macrophages play a critical role in overcoming respiratory infections caused by this pathogen.

ATCC 17978 encodes a microcin system with antimicrobial properties for contact-independent competition.

is a multidrug-resistant opportunistic pathogen that persists in the hospital environment and causes various clinical infections, primarily affecting immunocompromised patients. has evolved a wide range of mechanisms to compete with neighbouring bacteria. One such competition strategy depends on small secreted peptides called microcins, which exert antimicrobial effects in a contact-independent manner.

Human gut bacteria tailor extracellular vesicle cargo for the breakdown of diet- and host-derived glycans.

Extracellular vesicles (EV) are produced in all three domains of life, and their biogenesis have common ancient origins in eukaryotes and archaea. Although bacterial vesicles were discovered several decades ago and multiple roles have been attributed to them, no mechanism has been established for vesicles biogenesis in bacteria. For this reason, there is a significant level of skepticism about the biological relevance of bacterial vesicles.

Lipidome of the Genus Containing New Peptidolipid and Sphingolipid Families Revealed by Multiple-Stage Mass Spectrometry.

The anaerobic bacteria of the group including , , and in genus are among the most commonly found human gut microbiota. They are generally commensal but are also opportunistic pathogens. Both the inner and outer membranes of the cell envelope contain abundant lipids with diversified structures, and dissection of the lipid composition of the inner and outer membrane fractions is important for understanding the biogenesis of this multilaminate wall structure.

Replicative strains interfere with phagosomal maturation by modulating the vacuolar pH.

Bacterial pneumonia is a common infection of the lower respiratory tract that can afflict patients of all ages. Multidrug-resistant strains of are increasingly responsible for causing nosocomial pneumonias, thus posing an urgent threat. Alveolar macrophages play a critical role in overcoming respiratory infections caused by this pathogen.

Structure-function correlates of fibrinogen binding by adhesins critical in catheter-associated urinary tract infections.

Multidrug-resistant  infections are an urgent clinical problem and can cause difficult-to-treat nosocomial infections. During such infections, like catheter-associated urinary tract infections (CAUTI), rely on adhesive, extracellular fibers, called chaperone-usher pathway (CUP) pili for critical binding interactions. The uropathogenic strain, UPAB1, and the pan-European subclone II isolate, ACICU, use the CUP pili Abp1 and Abp2 (previously termed Cup and Prp, respectively) in tandem to establish CAUTIs, specifically to facilitate bacterial adherence and biofilm formation on the implanted catheter.

Catheterization of mice triggers resurgent urinary tract infection seeded by a bladder reservoir of .

The antibiotic-resistant bacterium is a leading cause of hospital-associated infections. Despite surveillance and infection control efforts, new strains are regularly isolated from health care facilities worldwide. In a mouse model of urinary tract infection, we found that mice infected with displayed high bacterial burdens in urine for several weeks.

Immunogenicity and protective efficacy of a prototype pneumococcal bioconjugate vaccine.

Capsular polysaccharides (CPSs), with which most pathogenic bacterial surfaces are decorated, have been used as the main components of glycoconjugate vaccines against bacterial diseases in clinical practice worldwide. Pneumococcal conjugate vaccines (PCVs) are administered globally to prevent invasive pneumococcal disease (IPD). While PCVs have played important roles in controlling IPD in all age groups, their empirical, and labor-intensive chemical conjugation yield poorly characterized, heterogeneous, and variably immunogenic vaccines, with poor immune responses in high-risk populations such as the elderly and patients with weak immune systems.

Evolutionarily stable gene clusters shed light on the common grounds of pathogenicity in the Acinetobacter calcoaceticus-baumannii complex.

Nosocomial pathogens of the Acinetobacter calcoaceticus-baumannii (ACB) complex are a cautionary example for the world-wide spread of multi- and pan-drug resistant bacteria. Aiding the urgent demand for novel therapeutic targets, comparative genomics studies between pathogens and their apathogenic relatives shed light on the genetic basis of human-pathogen interaction. Yet, existing studies are limited in taxonomic scope, sensing of the phylogenetic signal, and resolution by largely analyzing genes independent of their organization in functional gene clusters.

InvL, an Invasin-Like Adhesin, Is a Type II Secretion System Substrate Required for Acinetobacter baumannii Uropathogenesis.

Acinetobacter baumannii is an opportunistic pathogen of growing concern, as isolates are commonly multidrug resistant. While A. baumannii is most frequently associated with pulmonary infections, a significant proportion of clinical isolates come from urinary sources, highlighting its uropathogenic potential.

Lipidomics Analysis of Outer Membrane Vesicles and Elucidation of the Inositol Phosphoceramide Biosynthetic Pathway in Bacteroides thetaiotaomicron.

Approximately one-third of the human colonic microbiome is formed by bacteria from the genus . These bacteria produce a large amount of uniformly sized outer membrane vesicles (OMVs), which are equipped with hydrolytic enzymes that play a role in the degradation of diet- and host-derived glycans. In this work, we characterize the lipid composition of membranes and OMVs from Bacteroides thetaiotaomicron VPI-5482.

Development and Immunogenicity of a Prototype Multivalent Group B Bioconjugate Vaccine.

Group B (GBS) is a leading cause of neonatal infections and invasive diseases in nonpregnant adults worldwide. Developing a protective conjugate vaccine targeting the capsule of GBS has been pursued for more than 30 years; however, it has yet to yield a licensed product. In this study, we present a novel bioconjugation platform for producing a prototype multivalent GBS conjugate vaccine and its subsequent analytical and immunological characterizations.

Killing of Gram-negative and Gram-positive bacteria by a bifunctional cell wall-targeting T6SS effector.

The type VI secretion system (T6SS) is a powerful tool deployed by Gram-negative bacteria to antagonize neighboring organisms. Here, we report that ATCC 17978 (Ab17978) secretes D-lysine (D-Lys), increasing the extracellular pH and enhancing the peptidoglycanase activity of the T6SS effector Tse4. This synergistic effect of D-Lys on Tse4 activity enables Ab17978 to outcompete Gram-negative bacterial competitors, demonstrating that bacteria can modify their microenvironment to increase their fitness during bacterial warfare.