ABSTRACT In the lipopolysaccharides of Escherichia coli there are five distinct core oligosaccharide (core OS) structures, designated K-12 and R1 to R4. The objective this work was determine prevalences these OS types within species. Unique sequences in waa biosynthesis) gene operon were used develop a PCR-based system that facilitated unequivocal determination isolates E. . This applied 72 ECOR collection, compilation is considered be broadly representative genetic diversity Fifty (69.4%)...

Campylobacter jejuni is a highly prevalent human pathogen for which pathogenic and stress survival strategies remain relatively poorly understood. We previously found that C. strain 81-176 mutant defective key virulence attributes was also hyper-biofilm hyperreactive to the UV fluorescent dye calcofluor white (CFW). hypothesized screening CFW mutants would identify additional genes required pathogenesis properties. Surprisingly, two such harbored lesions in lipooligosaccharide (LOS) (waaF...

The impact of bacterial morphology on virulence and transmission attributes pathogens is poorly understood. prevalent enteric pathogen Campylobacter jejuni displays a helical shape postulated as important for colonization host interactions. However, this had not previously been demonstrated experimentally. C. thus good organism exploring the role factors modulating pathogenesis. We identified an uncharacterized gene, designated pgp1 (peptidoglycan peptidase 1), in calcofluor white-based...

Despite the importance of Campylobacter jejuni as a pathogen, little is known about fundamental aspects its peptidoglycan (PG) structure and factors modulating helical morphology. A PG dl-carboxypeptidase Pgp1 essential for maintenance C. shape was recently identified. Bioinformatic analysis revealed CJJ81176_0915 gene product co-occurring with in several organisms. Deletion cjj81176_0915 (renamed pgp2) resulted straight morphology, representing second affecting cell shape. The Δpgp2 mutant...

The diarrheal pathogen Campylobacter jejuni and other gastrointestinal bacteria encounter changes in osmolarity the environment, through exposure to food processing, upon entering host organisms, where osmotic adaptation can be associated with virulence. In this study, growth profiles, transcriptomics, phenotypic, mutant, single-cell analyses were used explore effects of hyperosmotic stress on C. jejuni. Increased inhibition correlated increased concentration, both ionic nonionic stressors...

ABSTRACT The enteric pathogen Campylobacter jejuni is a highly prevalent yet fastidious bacterium. Biofilms and surface polysaccharides participate in stress survival, transmission, virulence C. ; thus, the identification characterization of novel genes involved each process have important implications for pathogenesis. We found that reacts with calcofluor white (CFW), indicating presence harboring β1-3 and/or β1-4 linkages. CFW reactivity increased extended growth, under 42°C anaerobic...

ABSTRACT Campylobacter jejuni is a helix-shaped enteric bacterial pathogen and common cause of gastroenteritis. We recently developed mouse model for this human utilizing the SIGIRR-deficient strain, which exhibits significant intestinal inflammation in response to C. infection. In current study, was used define whether 's characteristic helical shape plays role its ability colonize elicit intestine. Mice were infected with previously characterized straight-rod Δ pgp1 pgp2 mutant strains,...

Campylobacter jejuni is a prevalent enteric pathogen that changes morphology from helical to coccoid under unfavorable conditions. Bacterial peptidoglycan maintains cell shape. As C. transformed coccoid, dipeptides increased and tri- tetrapeptides decreased. The DL-carboxypeptidase Pgp1 important for putative N-acetylmuramoyl-L-alanyl amidase AmiA were both involved in the transition. Mutants pgp1 amiA showed reduced formation, with ∆pgp1∆amiA producing minimal coccoids. Both ∆amiA...

Campylobacter jejuni is a Gram-negative helical bacterium. Its morphology, maintained by the peptidoglycan (PG) layer, plays key role in its transmission environment, colonization, and pathogenic properties. The previously characterized PG hydrolases Pgp1 Pgp2 are important for generating C. with deletion mutants being rod-shaped showing alterations their muropeptide profiles comparison to wild type. Homology searches bioinformatics were used identify additional gene products involved...

Campylobacter jejuni is a leading cause of bacterial gastroenteritis in the developed world. Despite its prevalence, mechanisms pathogenesis are poorly understood. Peptidoglycan (PG) important for helical shape, colonization, and host-pathogen interactions C. jejuni. Therefore, changes PG greatly impact physiology this organism. O-acetylation peptidoglycan (OAP) phenomenon proposed to be proper cell growth, characterized by acetylation C6 hydroxyl group N-acetylmuramic acid glycan backbone....

The waa gene cluster is responsible for the biosynthesis of lipopolysaccharide (LPS) core region in Escherichia coli and Salmonella: Homologs waaZ product are encoded by clusters Salmonella enterica E. strains with K-12 R2 types. Overexpression WaaZ S. led to a modified LPS structure showing truncations (where relevant) reduction amount O-polysaccharide side chains. Mass spectrometry nuclear magnetic resonance spectroscopy were used determine predominant structures an isolate R1 (waaZ...

In the Enterobacteriaceae, core oligosaccharide provides junction between highly conserved lipid A and remarkably diverse polysaccharide O antigen. The basic structure of inner (lipid A-proximal) is well conserved, perhaps reflecting constraints imposed by its involvement in structural integrity outer membrane. However, non-stoichiometric modifications do create some variants. may show more variation. Efforts to develop immunoprophylactic strategies based on require a detailed understanding...

The core oligosaccharide region of Klebsiella pneumoniae lipopolysaccharide contains some novel features that distinguish it from the corresponding in other members Enterobacteriaceae family, such as Escherichia coli and Salmonella. conserved outer unusual trisaccharide 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo)-(2,6)-GlcN-(1,4)-GalUA. In general, Kdo residues are normally found inner core, but K. pneumoniae, this residue provides ligation site for O polysaccharide. can also be...

In the Enterobacteriaceae, outer membrane is primarily comprised of lipopolysaccharides. The lipopolysaccharide molecule important in mediating interactions between bacterium and its environment those regions extending further away from cell surface show a higher amount structural diversity. hydrophobic lipid A highly conserved, due to role integrity membrane. Attached region core oligosaccharide. inner oligosaccharide (lipid proximal) backbone also well conserved. However,...

Campylobacter jejuni helical shape is important for colonization and host interactions with straight mutants having altered biological properties. Passage on calcofluor white (CFW) resulted in C. 81-176 isolates morphology changes: either a from frameshift mutations single nucleotide polymorphisms peptidoglycan hydrolase genes pgp1 or pgp2 reduction curvature due mutation cjj81176_1105, putative endopeptidase. Shape defects were restored by complementation. Whole genome sequencing of...

Phenotypic variation is prevalent in the zoonotic pathogen Campylobacter jejuni, leading agent of enterocolitis developed world. Heterogeneity enhances survival and adaptive malleability bacterial populations because variable phenotypes may allow some cells to be protected against future stress. Exposure hyperosmotic stress previously revealed differences growth between C. jejuni strain 81-176 colonies due resistant or sensitive phenotypes, these isolated continued produce progeny with...

Helicobacter pylori and Campylobacter jejuni are human pathogens causative agents of gastric ulcers/cancer gastroenteritis, respectively. Recent studies have uncovered a series proteases that responsible for maintaining the helical shape these organisms. The H. metalloprotease Csd4 its C. homologue Pgp1 cleave amide bond between meso-diaminopimelate iso-d-glutamic acid in truncated peptidoglycan side chains. Deletion either csd4 or pgp1 results bacteria with straight rod phenotype, reduced...

In Escherichia coli and Salmonella enterica, the core oligosaccharide backbone of lipopolysaccharide is modified by phosphoryl groups. The negative charges provided these residues are important in maintaining barrier function outer membrane. contrast, Klebsiella pneumoniae lacks groups its but instead contains galacturonic acid that proposed to serve a similar membrane stability. Gla(KP) UDP-galacturonic C4-epimerase provides for synthesis, enzyme was biochemically characterized because...