Re-sequencing of a virulent strain of Campylobacter jejuni NCTC11168 reveals potential virulence factors.

In vitro passage of Campylobacter jejuni strains results in phenotypic changes and a general loss of virulence, as is the case with the genome-sequenced strain C. jejuni NCTC11168. Re-sequencing of a virulent strain of NCTC11168 identified 41 SNPs or indels involving 20 genes, four intergenic regions and three pseudogenes.

The Campylobacter jejuni Dps homologue is important for in vitro biofilm formation and cecal colonization of poultry and may serve as a protective antigen for vaccination.

In this work, we investigated the Campylobacter jejuni dps (DNA binding protein from starved cells) gene for a role in biofilm formation and cecal colonization in poultry. In vitro biofilm formation assays were conducted with stationary-phase cells in cell culture plates under microaerophilic conditions. These studies demonstrated a significant (>50%) reduction in biofilm formation by the C.

Investigations of Salmonella enterica serovar newport infections of oysters by using immunohistochemistry and knockout mutagenesis.

The consumption of raw oysters is an important risk factor in the acquisition of food-borne disease, with Salmonella being one of a number of pathogens that have been found in market oysters. Previous work by our lab found that Salmonella was capable of surviving in oysters for over 2 months under laboratory conditions, and this study sought to further investigate Salmonella's tissue affinity and mechanism of persistence within the oysters. Immunohistochemistry was used to show that Salmonella was capable of breaching the epithelial barriers, infecting the deeper connective tissues of the oysters, and evading destruction by the oysters' phagocytic hemocytes.

A Campylobacter jejuni Dps homolog has a role in intracellular survival and in the development of campylobacterosis in neonate piglets.

Iron acquisition is an absolute requirement by most microorganisms for host survival. In this work, we investigated the Campylobacter jejuni iron binding Dps protein for a potential role in virulence. In vitro assays using J774A.

Prevalence and characterization of Salmonella serovars isolated from oysters served raw in restaurants.

To determine if Salmonella-contaminated oysters are reaching consumer tables, a survey of raw oysters served in eight Tucson restaurants was performed from October 2007 to September 2008. Salmonella spp. were isolated during 7 of the 8 months surveyed and were present in 1.

Survival of Salmonella Newport in oysters.

Salmonella enterica is the leading cause of laboratory-confirmed foodborne illness in the United States and raw shellfish consumption is a commonly implicated source of gastrointestinal pathogens. A 2005 epidemiological study done in our laboratory by Brands et al., showed that oysters in the United States are contaminated with Salmonella, and in particular, a specific strain of the Newport serovar.

Antimicrobial edible apple films inactivate antibiotic resistant and susceptible Campylobacter jejuni strains on chicken breast.

Unlabelled: Campylobacter jejuni is the leading cause of bacterial diarrheal illness worldwide. Many strains are now becoming multidrug resistant. Apple-based edible films containing carvacrol and cinnamaldehyde were evaluated for bactericidal activity against antibiotic resistant and susceptible C.

Complete genome sequence of Campylobacter jejuni strain S3.

Campylobacter jejuni is one of the leading causes of bacterial gastroenteritis in the world; however, there is only one complete genome sequence of a poultry strain to date. Here we report the complete genome sequence and annotation of the second poultry strain, C. jejuni strain S3.

Carvacrol and cinnamaldehyde inactivate antibiotic-resistant Salmonella enterica in buffer and on celery and oysters.

The emergence of antibiotic-resistant Salmonella is of concern to food processors. The objective of this research was to identify antimicrobial activities of cinnamaldehyde and carvacrol against antibiotic-resistant Salmonella enterica in phosphate-buffered saline (PBS) and on celery and oysters. Twenty-three isolates were screened for resistance to seven antibiotics.

Analysis of the pan genome of Campylobacter jejuni isolates recovered from poultry by pulsed-field gel electrophoresis, multilocus sequence typing (MLST), and repetitive sequence polymerase chain reaction (rep-PCR) reveals different discriminatory capabilities.

Campylobacter jejuni is one of the leading bacterial causes of food-borne illness in the USA. Molecular typing methods are often used in food safety for identifying sources of infection and pathways of transmission. Moreover, the identification of genetically related isolates (i.

Comparison of in vitro virulence factors of Campylobacter jejuni to in vivo lesion production.

Campylobacter jejuni is recognized as one of the most common agents of food-borne bacterial gastroenteritis in humans. Previous work has shown that C. jejuni isolates vary in their ability to invade and survive in laboratory grown cells.

Comparative metagenomics reveals host specific metavirulomes and horizontal gene transfer elements in the chicken cecum microbiome.

Background: The complex microbiome of the ceca of chickens plays an important role in nutrient utilization, growth and well-being of these animals. Since we have a very limited understanding of the capabilities of most species present in the cecum, we investigated the role of the microbiome by comparative analyses of both the microbial community structure and functional gene content using random sample pyrosequencing. The overall goal of this study was to characterize the chicken cecal microbiome using a pathogen-free chicken and one that had been challenged with Campylobacter jejuni.

Plant-derived compounds inactivate antibiotic-resistant Campylobacter jejuni strains.

Sixty-three Campylobacter jejuni isolates were screened for their resistance to the antibiotics ampicillin, cefaclor, ciprofloxacin, erythromycin, gentamycin, tetracycline, and trimethoprim-sulfamethoxazole. Based on this screen, the resistant strains D28a and H2a and the nonresistant strain A24a were selected for evaluation of their resistance and susceptibility to inactivation by cinnamaldehyde and carvacrol, the main constituents of plant-derived cinnamon and oregano oils, respectively. Different concentrations (0.

Characterization of genetically matched isolates of Campylobacter jejuni reveals that mutations in genes involved in flagellar biosynthesis alter the organism's virulence potential.

Phenotypic and genotypic evidence suggests that not all Campylobacter jejuni isolates are pathogenic for humans. We hypothesized that differences in gene content or gene expression alter the degree of pathogenicity of C. jejuni isolates.

Characterization of Campylobacter jejuni biofilms under defined growth conditions.

Campylobacter jejuni is a major cause of human diarrheal disease in many industrialized countries and is a source of public health and economic burden. C. jejuni, present as normal flora in the intestinal tract of commercial broiler chickens and other livestock, is probably the main source of human infections.

Human and animal enteric caliciviruses in oysters from different coastal regions of the United States.

Food-borne diseases are a major cause of morbidity and hospitalization worldwide. Enteric caliciviruses are capable of persisting in the environment and in the tissues of shellfish. Human noroviruses (HuNoVs) have been implicated in outbreaks linked to shellfish consumption.

Genotypes and antibiotic resistance of salmonella newport isolates from U.S. market oysters.

The consumption of raw oysters contributes to food-borne diseases such as salmonellosis. Prevalence studies in our laboratory have shown that Salmonella spp. were present in 7.

Potential virulence and antimicrobial susceptibility of Campylobacter jejuni isolates from food and companion animals.

Infection in humans with Campylobacter jejuni is commonly associated with exposure to food animal fecal material. In this study, we report on the recovery, potential for virulence and antimicrobial resistance levels of C. jejuni isolated from food and companion animals.

Prevalence of Salmonella spp. in oysters in the United States.

Food-borne diseases such as salmonellosis can be attributed, in part, to the consumption of raw oysters. To determine the prevalence of Salmonella spp. in oysters, oysters harvested from 36 U.

FeoB is not required for ferrous iron uptake in Campylobacter jejuni.

Among strains of Campylobacter jejuni, levels of ferrous iron (Fe2+) uptake was comparable. However, C. jejuni showed a lower level of ferrous iron uptake than Escherichia coli.

The pathogenesis of Campylobacter jejuni-mediated enteritis.

Campylobacter jejuni, a gram-negative spiral shaped bacterium, is a frequent cause of gastrointestinal food-borne illness in humans throughout the world. Illness with C. jejuni ranges from mild to severe diarrheal disease.

Cloning and characterization of a Campylobacter jejuni iron-uptake operon.

We report that C. jejuni modifies its outer membrane protein (OMP) repertoire when cultivated under iron-limiting conditions such as during incubation with epithelial cells. To identify genes encoding de novo expressed OMPs, a C.

Role of catalase in Campylobacter jejuni intracellular survival.

The ability of Campylobacter jejuni to penetrate normally nonphagocytic host cells is believed to be a key virulence determinant. Recently, kinetics of C. jejuni intracellular survival have been described and indicate that the bacterium can persist and multiply within epithelial cells and macrophages in vitro.

Analysis of the lytic activity of the Serpulina hyodysenteriae hemolysin.

The hemolysins of Serpulina hyodysenteriae are active at 27 to 40 degrees C and pH 3 to 9 and are unaffected by enzymatic inhibitors. Pore formation was demonstrated by the inhibition of hemolysis with molecules of 2.0 to 2.

Induction of gross and microscopic lesions of porcine proliferative enteritis by Lawsonia intracellularis.

Objective: To evaluate experimental induction of porcine proliferative enteritis (PPE), using cell cultured Lawsonia intracellularis (ileal symbiont intracellularis), and to determine whether dexamethasone administration or age of the host or both affects susceptibility to L intracellularis infection.

Animals: Thirty-two 3- or 7-week-old pigs.

Procedures: Lawsonia intracellularis was extracted from tissue with lesions of PPE and was subcultured in a continuous Henle 407 cell line at 37 C under an atmosphere of 5% CO2.