By means of the gentamicin HEp-2 cell invasion assay, it was demonstrated that 82% of the Campylobacters tested were cell-invasive, including 83% of isolates from bloody diarrhoea and 80% of isolates from watery diarrhoea. The large number of invasive strains from watery diarrhoea suggests the possible role of invasiveness in the production of watery diarrhoea. Whether this stage can progress further to more severe symptoms such as bloody diarrhoea remains to be elucidated. Whether this progression to bloody diarrhoea occurs as a result of toxin production is still debatable. In Vero cells, invasion was less efficient and intracellular multiplication was not observed.
Campylobacter is reported as a major cause of foodborne illness worldwide. Consumption of contaminated chicken meat is considered a significant risk factor of Campylobacter infection in humans. This study investigated the occurrence of non-Campylobacter jejuni-Campylobacter coli, in broiler chickens (n = 210) and chicken meat (n = 109). The samples were collected from seven broiler chicken farms (n = 210 cloacal swabs), 11 markets (n = 84 chicken meat), and 5 supermarkets (n = 25 chicken meat) located in different districts of Selangor State. Campylobacter were isolated from cloacal swabs using the Cape Town Protocol and from meat samples using the method of Duffy et al. (2007) with some modifications for Campylobacter isolations which were reported effective in the isolation of non-C. jejuni-C. coli Campylobacter species. The isolates were identified by Gram staining for cellular morphology, wet mount for motility and biochemical tests. Confirmation of presumed Campylobacter isolates was carried out using multiplex PCR (mPCR). One hundred seven (107/210) or 50.9% and twenty-nine (29/109) or 26.6% of chickens and chicken meat samples respectively were positive for Campylobacter species. Among the Campylobacter isolates from chickens, C. jejuni was the most predominantly isolated species (69.5%), followed by C. coli (16.2%). Campylobacter fetus and C. upsaliensis were the non-C. jejuni-C. coli Campylobacter species isolated in this study, at 9.3% and 2.5% respectively. Overall, the findings indicated broiler chickens were colonized not only by the common Campylobacter species but also by other Campylobacter species. We found the Cape Town Protocol useful to detect the occurrence of non-C. jejuni-C. coli isolates in chickens.
Eight-five clinical and 15 poultry isolates of Campylobacter species were characterised by biotyping, serotyping and by using a radiolabelled DNA probe. A total of 80% of the isolates from both sources were identified as C. jejuni. Also amongst the clinical strains were 5 c. jejuni subsp. doylei, 7 C. coli, 3 C. lari and 8 were untypable. The similarity in the distribution of C. jejuni in the clinical and poultry isolates adds credibility to published reports of chickens being the most common source of Campylobacter infections. Although the gold standard for identification of C. jejuni is the DNA probe, serotyping is more discriminating while biotyping is the most feasible method in most laboratories.
Given that Campylobacter jejuni is recognized as the most common cause of bacterial gastroenteritis worldwide, recent findings showing comparable levels of Campylobacter concisus in patients with gastroenteritis would suggest that this bacterium is clinically important. The prevalence and abundance of Campylobacter concisus in stool samples collected from patients with acute gastroenteritis was examined using quantitative real-time PCR. The associated virulence determinants exotoxin 9 and zonula occludens toxin DNA were detected for Campylobacter concisus-infected samples using real-time PCR. Campylobacter concisus was detected at high prevalence in patients with gastroenteritis (49.7 %), higher than that observed for Campylobacter jejuni (∼5 %). The levels of Campylobacter concisus were putatively classified into clinically relevant and potentially transient subgroups based on a threshold developed using Campylobacter jejuni levels, as the highly sensitive real-time PCR probably detected transient passage of the bacterium from the oral cavity. A total of 18 % of patients were found to have clinically relevant levels of Campylobacter concisus, a significant number of which also had high levels of one of the virulence determinants. Of these patients, 78 % were found to have no other gastrointestinal pathogen identified in the stool, which strongly suggests a role for Campylobacter concisus in the aetiology of gastroenteritis in these patients. These results emphasize the need for diagnostic laboratories to employ identification protocols for emerging Campylobacter species. Clinical follow-up in patients presenting with high levels of Campylobacter concisus in the intestinal tract is needed, given that it has been associated with more chronic sequelae.
The importance of Campylobacter and Salmonella as foodborne pathogens is well recognised globally. A recent work in Penang found ducks in commercial farms were infected with these organisms. The aim of the study was to detect the presence of Campylobacter and Salmonella in ducks and Salmonella in duck eggs in farms in a small part of Selangor. Cloacal swabs were obtained from 75 ducks and 30 duck eggs from three farms. The isolation and identification of Campylobacter and Salmonella were done using conventional methods. Twelve percent of Campylobacter and 16.0% of Salmonella were isolated from the ducks sampled. Salmonella was absent on and in eggs. Campylobacter isolates consisted of 22% Campylobacter jejuni and the remaining was Campylobacter coli. Three Salmonella serovars identified were Salmonella Agona, S. Braenderup and S. Corvallis. The presence of Campylobacter and Salmonella in ducks may cause contamination of the meat during processing and handling which can constitute public health hazard. Moreover, the farm workers may be exposed to the organisms through contact with the infected animals.