Detection of Seven Virulence and Toxin Genes of Campylobacter jejuni Isolates from Danish Turkeys by PCR and Cytolethal Distending Toxin Production of the Isolates

Abstract

A total of 117 Campylobacter jejuni isolates from Danish turkeys were tested for the presence of seven virulence and toxin genes by PCR. One hundred seventeen (100%) isolates were positive for flaA, cadF, and ceuE gene primers. One hundred three (88%) isolates were positive for cdt gene cluster PCR detection (cdt gene cluster-PCR), whereas 101 (86.3%), 102 (87.2%), and 110 (94%) isolates were positive for cdtA-, cdtB-, and cdtC-PCR, respectively. Only 39 (33.3%) isolates were positive for virB11. Of 117 isolates, 114 (97.4%) produced cytolethal distending toxin (CDT) in Vero cell assays, 105 (89.7%) in Colon 205 assays, and 109 (93.2%) in chicken embryo cell assays. The CDT titers were determined in Vero cell assays. Of 117 isolates, 50 (42.7%) produced a CDT titer of 1:100, 29 (24.8%) of 1:50, and 27 (23%) of 1:5 to 1:10; 8 (6.8%) produced a CDT titer at undiluted supernatants and 3 (2.6%) produced no toxin. Twenty-nine C. jejuni isolates that were PCR negative for one or more individual cdt toxin genes also produced low or no CDT toxin. The high prevalence of the seven virulence and toxin genes demonstrates that these putative pathogenic determinants are widespread among Campylobacter isolates from turkeys and calls for further investigation for the elimination of Campylobacter infection in industrial turkey production and in industrial food chains.

PCR Detection of Four Virulence-Associated Genes of Campylobacter jejuni Isolates from Thai Broilers and Their Abilities of Adhesion to and Invasion of INT-407 Cells

“…The gene dnaJ was detected in all strains of Campylobacter caecal isolates. Only 76% of cadF genes were detected in all 49 chicken isolates which is contrary to the 100% detection of cadF genes from the isolates of Danish turkeys [4,5]. This result may be caused by geographic and species differences.…”

C57BL/6 and Congenic Interleukin-10-Deficient Mice Can Serve as Models ofCampylobacter jejuniColonization and Enteritis

“…These traits are suggestive of genomic and phenotypic plasticity responsive to a dynamic environment, especially the GI tract (21,69). Genetic variation in genes associated with virulence has also been demonstrated in collections of field isolates of C. jejuni (2,3,10). The outcome of C. jejuni infection likely depends on many factors including the strain, dose, number, and timing of challenges; innate and adaptive immune status; passive immunity from the mother; and the presence of other enteric pathogens, commensals, and concurrent systemic infections.…”

Molecular diagnostic protocols for bovine genital campylobacteriosis using comparative genomics and virulence studies

“…Other studies investigated the prevalence of cadF in C. coli and/or C. jejuni isolates and all examined strains (respectively n=117; n=40; n=46) were found positive by either PCR or immunoblot further suggesting that CadF may play an important role in Campylobacter virulence (Bang et al, 2003(Bang et al, , 2004Konkel et al, 1999).…”

“…By studying C. coli and C. jejuni, virulence factors associated with pathogenicity have been identified including flagellar motility, adherence of bacterial cells to mucosa, leading to host cell invasion and production of toxins (Bang et al, 2004;Bang et al, 2003;Ketley, 1997;Wassenaar, 1997). In the absence of extensive information for C. fetus pathogenesis, these factors can be investigated in other Campylobacter spp..…”

“…Likewise, flaA was amplified in all C. coli and C. jejuni porcine and bovine strains (n=40) tested and in a large number (n=117) of C. jejuni turkey strains using primers reported by Nachamkin et al (1993), confirming the presence of this flagellin gene in many Campylobacter spp. field isolates (Bang et al, 2003(Bang et al, , 2004 .…”