Multiplex Determination of K-Antigen and Colanic Acid Capsule Variants of .

is associated with the ingestion of contaminated reconstituted powdered infant formula (PIF), resulting in necrotizing enterocolitis, sepsis and meningitis in neonatal infants. Potential virulence determinants include the variable capsular polysaccharides; K-antigen and colanic acid (CA). Strains encoding for the capsule variant K2:CA2 have been strongly associated with neonatal meningitis cases.

extracellular vesicles harboring cytolethal distending toxin bind host cell glycans and induce cell cycle arrest in host cells.

Unlabelled: Cytolethal distending toxins (CDTs) are released by Gram-negative pathogens into the extracellular medium as free toxin or associated with extracellular vesicles (EVs), commonly known as outer membrane vesicles (OMVs). CDT production by the gastrointestinal pathogen has been implicated in colorectal tumorigenesis. Despite CDT being a major virulence factor for , little is known about the EV-associated form of this toxin.

A Guideline for Assessment and Characterization of Bacterial Biofilm Formation in the Presence of Inhibitory Compounds.

jejuni, a zoonotic foodborne pathogen, is the worldwide leading cause of acute human bacterial gastroenteritis. Biofilms are a significant reservoir for survival and transmission of this pathogen, contributing to its overall antimicrobial resistance. Natural compounds such as essential oils, phytochemicals, polyphenolic extracts, and D-amino acids have been shown to have the potential to control biofilms formed by bacteria, including spp.

Diverse Sensory Repertoire of Paralogous Chemoreceptors Tlp2, Tlp3, and Tlp4 in .

Campylobacter jejuni responds to extracellular stimuli via transducer-like chemoreceptors (Tlps). Here, we describe receptor-ligand interactions of a unique paralogue family of dCache_1 (double lcium channels and motaxis) chemoreceptors: Tlp2, Tlp3, and Tlp4. Phylogenetic analysis revealed that Tlp2, Tlp3, and Tlp4 receptors may have arisen through domain duplications, followed by a divergent evolutionary drift, with Tlp3 emerging more recently, and unexpectedly, responded to glycans, as well as multiple organic and amino acids with overlapping specificities.

Extracellular c-di-GMP Plays a Role in Biofilm Formation and Dispersion of .

Cyclic diguanosine monophosphate (c-diGMP) is a ubiquitous second messenger involved in the regulation of many signalling systems in bacteria, including motility and biofilm formation. Recently, it has been reported that c-di-GMP was detected in C. jejuni DRH212; however, the presence and the role of c-di-GMP in other C.

A Review of the Advantages, Disadvantages and Limitations of Chemotaxis Assays for spp.

Reproducible qualitative and quantitative assessment of bacterial chemotactic motility, particularly in response to chemorepellent effectors, is experimentally challenging. Here we compare several established chemotaxis assays currently used to investigate chemotaxis, with the aim of improving the correlation between different studies and establishing the best practices. We compare the methodologies of capillary, agar, and chamber-based assays, and discuss critical technical points, in terms of reproducibility, accuracy, and the advantages and limitations of each.

Biofilms: Potential of Natural Compounds to Disrupt Transmission.

Microbial biofilms occur naturally in many environmental niches and can be a significant reservoir of infectious microbes in zoonotically transmitted diseases such as that caused by , the leading cause of acute human bacterial gastroenteritis world-wide. The greatest challenge in reducing the disease caused by this organism is reducing transmission of to humans from poultry via the food chain. Biofilms enhance the stress tolerance and antimicrobial resistance of the microorganisms they harbor and are considered to play a crucial role for spp.

The dCache Chemoreceptor TlpA of Helicobacter pylori Binds Multiple Attractant and Antagonistic Ligands via Distinct Sites.

The Helicobacter pylori chemoreceptor TlpA plays a role in dampening host inflammation during chronic stomach colonization. TlpA has a periplasmic dCache_1 domain, a structure that is capable of sensing many ligands; however, the only characterized TlpA signals are arginine, bicarbonate, and acid. To increase our understanding of TlpA's sensing profile, we screened for diverse TlpA ligands using ligand binding arrays.

The chemoreceptor Tlp10 has a bimodal ligand-binding domain and specificity for multiple classes of chemoeffectors.

is a bacterial pathogen that is a common cause of enteritis in humans. We identified a previously uncharacterized type of sensory domain in the periplasmic region of the chemoreceptor Tlp10, termed the DAHL domain, that is predicted to have a bimodular helical architecture. Through two independent ligand-binding sites in this domain, Tlp10 responded to molecular aspartate, isoleucine, fumarate, malate, fucose, and mannose as attractants and to arginine, galactose, and thiamine as repellents.

Inhibition of Biofilm Formation by D-Amino Acids.

The ability of bacterial pathogens to form biofilms is an important virulence mechanism in relation to their pathogenesis and transmission. Biofilms play a crucial role in survival in unfavorable environmental conditions, acting as reservoirs of microbial contamination and antibiotic resistance. For intestinal pathogen , biofilms are considered to be a contributing factor in transmission through the food chain and currently, there are no known methods for intervention.

New approach to distinguishing chemoattractants, chemorepellents and catabolised chemoeffectors for Campylobacter jejuni.

Unlabelled: Chemotactic behaviour is an important part of the lifestyle of motile bacteria and enables cells to respond to various environmental stimuli. The Hard Agar Plug (HAP) method is used to study the chemotactic behaviour of bacteria, including the fastidious microaerophile Campylobacter jejuni, an intestinal pathogen of humans. However, the traditional HAP assay is not quantitative, is unsuitable for chemotaxis observation over short time periods and for the investigation of repellent taxis, and is prone to false-positive and -negative results.

Lighting up my life: a LOV-based fluorescent reporter for Campylobacter jejuni.

In this study, a LOV-based fluorescent reporter (light, oxygen, or voltage-sensing domains of phototropin), termed iLOV, was adapted for Campylobacter jejuni and used to investigate promoter activity via monitoring fluorescence intensity and to study the localisation of two chemotaxis proteins. The pC46 complementation vector contains coding sequence from cj0046, a C. jejuni NCTC11168 pseudo-gene and is used to integrate cloned genes onto the C.