The colonization of broiler chickens with Campylobacter jejuni: some epidemiological investigations.

Between June 1990 and July 1991, broiler chickens from 49 flocks from 23 farms were examined for the carriage of Campylobacter jejuni at slaughter. Thirty-seven flocks (76%) were campylobacter-positive. Prevalence of campylobacter-colonization was not associated with any of a variety of factors such as water source and broiler house floor structure. There was also no apparent seasonal variation in carriage. Investigations on one farm indicated that dipping boots in disinfectant before workers entered broiler houses either delayed or prevented colonization with C. jejuni.     

Evaluation of a Campylobacter jejuni N-glycan-ExoA glycoconjugate vaccine to reduce C. jejuni colonisation in chickens

Campylobacter jejuni is the leading bacterial cause of human gastroenteritis worldwide and handling or consumption of contaminated poultry meat is the key source of infection. Glycoconjugate vaccines containing the C. jejuni N-glycan have been reported to be partially protective in chickens. However, our previous studies with subunit vaccines comprising the C. jejuni FlpA or SodB proteins with up to two or three C. jejuni N-glycans, respectively, failed to elicit significant protection. In this study, protein glycan coupling technology was used to add up to ten C. jejuni N-glycans onto a detoxified form of Pseudomonas aeruginosa exotoxin A (ExoA). The glycoprotein, G-ExoA, was evaluated for efficacy against intestinal colonisation of White Leghorn chickens by C. jejuni strains M1 and 11168H relative to unglycosylated ExoA. Chickens were challenged with the minimum dose required for reliable colonisation, which was 10² colony-forming units (CFU) for strain M1 and and 10⁴ CFU for strain 11168H. Vaccine-specific serum IgY was detected in chickens vaccinated with both ExoA and G-ExoA. However, no reduction in caecal colonisation by C. jejuni was observed. While the glycan dose achieved with G-ExoA was higher than FlpA- or SodB-based glycoconjugates that were previously evaluated, it was lower than that of glycoconjugates where protection against C. jejuni has been reported, indicating that protection may be highly sensitive to the amount of glycan presented and/or study-specific variables.     

The heat-sensitivity of Campylobacter jejuni in milk.

It is now established that milk can be a vehicle for the spread of enteritis due to Campylobacter jejuni. By determining the lethal effect of heat on six isolates it has been shown that C. jejuni is unlikely to survive pasteurization.     

The isolation of Campylobacter jejuni from flies.

Living flies collected from three locations were cultured on selective medium for Campylobacter spp. Campylobacter jejuni was isolated from five (2.4%) of 210 flies examined. These results suggest that the potential hazard to health from the transmission of campylobacters from animals to human food by flies is small.     

Long-lasting Campylobacter jejuni contamination of milk associated with gastrointestinal illness in a farming family

This report describes an outbreak of gastroenteritis of 5 months' duration in a farming family, associated with the consumption of unpasteurized cows' milk, where Campylobacter jejuni was implicated. A total of six individuals in the family acquired the illness, and two had several episodes of diarrhoea within the 5-month period. Identical PFGE genotypes of C. jejuni were isolated from human and bovine faeces, and bulk tank milk samples. Incompletely sealed rubber liners fitted to a milking machine shortly before the outbreak started was the probable reason, allowing faecal material to contaminate the milk over the period concerned.     

Faecal contamination of a municipal drinking water distribution system in association with Campylobacter jejuni infections

After heavy rains Campylobacter jejuni together with high counts of Escherichia coli, other coliforms and intestinal enterococci were detected from drinking water of a municipal distribution system in eastern Finland in August 2004. Three patients with a positive C. jejuni finding, who had drunk the contaminated water, were identified and interviewed. The pulsed-field gel electrophoresis (PFGE) genotypes from the patient samples were identical to some of the genotypes isolated from the water of the suspected contamination source. In addition, repetitive DNA element analysis (rep-PCR) revealed identical patterns of E. coli and other coliform isolates along the distribution line. Further on-site technical investigations revealed that one of the two rainwater gutters on the roof of the water storage tower had been in an incorrect position and rainwater had flushed a large amount of faecal material from wild birds into the drinking water. The findings required close co-operation between civil authorities, and application of cultivation and genotyping techniques strongly suggested that the municipal drinking water was the source of the infections. The faecal contamination associated with failures in cleaning and technical management stress the importance of instructions for waterworks personnel to perform maintenance work properly.     

Epidemiological aspects of Campylobacter jejuni enteritis.

An epidemiological study on Campylobacter jejuni enterocolitis was performed in an urban Swedish community. The study included 55 patients gathered during a six-month period. Forty-one of the 55 patients (75%) were infected outside Sweden. Campylobacter enterocolitis was rare among children within the country. Patients infected in Sweden had eaten chicken significantly more often than a corresponding control group. Seven out of nine chicken consuming campylobacter patients also had prepared the fresh chicken alone, and none of their family members became ill. Thus the preparation of food contaminated with Campylobacter seems to elevate the risk for contracting the disease. Sick household pets transmitted the campylobacter infection to two patients. Forty-six of the patients had a total of 85 close household members. Three definite secondary cases were found. There was no evidence of transmission of Campylobacter by food prepared by two cooks who were working while still being asymptomatic excreters. Clinical reinfection with Campylobacter was observed in one patient. No patients became long-term carriers of Campylobacter.     

Extended phage-typing scheme for Campylobacter jejuni and Campylobacter coli.

The extended phage-typing scheme described for Campylobacter jejuni and Campylobacter coli has established 46 different phage types using 19 typing phages. Altogether 754 campylobacter isolates, 672 C. jejuni and 82 C. coli, isolated from human and non-human sources received from 17 different countries were phage-typed. Overall, 80.6% of the total isolates were typable. Among typable strains, 9 phage types (3, 5, 10, 11, 18, 19, 23, 26 and 44) represented 57.0% of the strains, 21.3% of the strains belonged to another 37 phage types and the remaining 2.3% of isolates were designated atypical. The most common phage type 11 (140/754) was frequently observed among C. jejuni isolates from human (113/561) and non-human sources (18/111), whereas type 44 was frequent among C. coli isolates from human (22/59) and from non-human sources (8/23). A study of the animal host-associations of common phage types showed that contaminated cattle and poultry appear to be the most common sources of human infection. The greatest variety of phage types was observed in Canada (24 phage types), followed by Portugal (17 types) and the UK (14 types), reflecting the larger sample sizes from these countries. Phage type 11 was encountered in 12 different countries and prevalence of other phage types varied from one country to another. The number of isolates typable with the scheme varied from 93.2% (261/280) in Canada to 61% (47/77) in Thailand. However, the number and diversity of phage types makes phage typing the method of choice in epidemiological studies of campylobacter infections.     

Superoxide dismutase SodB is a protective antigen against Campylobacter jejuni colonisation in chickens

Campylobacter is the leading cause of foodborne diarrhoeal illness in the developed world and consumption or handling of contaminated poultry meat is the principal source of infection. Strategies to control Campylobacter in broilers prior to slaughter are urgently required and are predicted to limit the incidence of human campylobacteriosis. Towards this aim, a purified recombinant subunit vaccine based on the superoxide dismutase (SodB) protein of C. jejuni M1 was developed and tested in White Leghorn birds. Birds were vaccinated on the day of hatch and 14 days later with SodB fused to glutathione S-transferase (GST) or purified GST alone. Birds were challenged with C. jejuni M1 at 28 days of age and caecal Campylobacter counts determined at weekly intervals. Across three independent trials, the vaccine induced a statistically significant 1 log₁₀ reduction in caecal Campylobacter numbers in vaccinated birds compared to age-matched GST-vaccinated controls. Significant induction of antigen-specific serum IgY was detected in all vaccinated birds, however the magnitude and timing of SodB-specific IgY did not correlate with lower numbers of C. jejuni. Antibodies from SodB-vaccinated chickens detected the protein in the periplasm and not membrane fractions or on the bacterial surface, suggesting that the protection observed may not be strictly antibody-mediated. SodB may be useful as a constituent of vaccines for control of C. jejuni infection in broiler birds, however modest protection was observed late relative to the life of broiler birds and further studies are required to potentiate the magnitude and timing of protection.     

An outbreak of Campylobacter jejuni gastroenteritis linked to meltwater contamination of a municipal well

A large outbreak of Campylobacter jujuni gastroenteritis attributed to contamination of an unchlorinated municipal water system was investigated. Unlike most previous summer outbreaks, this one began in early spring and was attributed to meltwater entering one or more municipal wells. 241 suspected cases were documented, but retrospective information from local health care workers suggested a much larger outbreak. 45 laboratory-confirmed cases participated in a case-control study which showed a significant association between infection and amount of town water consumed. Stool specimens from 29 patients were studied with detailed serotyping by the method of Lior, with eight known serotypes and one previously unknown one identified. It is concluded that intensive surveillance of water quality during periods of spring runoff is essential, and that timely reporting of disease outbreak patterns in emergency department settings is necessary to protect the public's health.     

Campylobacter jejuni strains from patients with Guillain-Barr�� syndrome.

Guillain-Barré syndrome (GBS), an acute demyelinating peripheral neuropathy, may be triggered by an acute infectious illness; infection with Campylobacter jejuni is the most frequently reported antecedent event. In Japan, O:19 is the most common serotype among GBS-associated C. jejuni strains. To determine whether serotype O:19 occurs among GBS-associated strains in the United States and Europe, we serotyped seven such strains and found that two (29%) of seven GBS-associated strains from patients in the United States and Germany were serotype O:19. To determine whether GBS-associated strains may be resistant to killing by normal human serum (NHS), we studied the serum susceptibility of 17 GBS- and 27 enteritis-associated strains (including many O:19 and non-O:19 strains) using C. jejuni antibody positive (pool 1) or negative (pool 2) human serum. Using pool 1 serum we found that one (6%) of 18 serotype O:19 strains compared with 11 (42%) of 26 non-O:19 strains were killed; results using pool 2 serum were nearly identical. Finally, 8 O:19 and 8 non-O:19 strains were not significantly different in their ability to bind complement component C3. Serotype O:19 C. jejuni strains were overrepresented among GBS-associated strains in the United States and Germany and were significantly more serum-resistant than non-O:19 strains. The mechanism of this resistance appears unrelated to C3 binding.     

The virulence of clinical and environmental isolates of Campylobacter jejuni.

The virulence of Campylobacter jejuni and C. coli isolated from various water sources was compared with that of clinical strains by in vitro assays of adhesion, invasion and cytotoxicity to HeLa cells. Variation in degree of attachment was observed, but this did not appear to be related to strain source, However, water strains were less invasive and less cytotoxic to HeLa cells than clinical strains as shown by immunofluorescence and electron microscopy. These differences were particularly evident between clinical and water isolates of the same serotype and biotype implicated in an outbreak of campylobacter enteritis in a school. The enhanced virulence of the clinical isolates, possibly induced by passage, was confirmed by colonization tests on infant mice.     

人类空肠弯曲菌感染的流行病学

八十年代以来,随着对空肠弯曲菌感染研究的不断深入,有关本病的流行病学也获得了较全面的认识[1]。     

Experimental colonization of broiler chicks with Campylobacter jejuni

Minimal colonization inocula for two broiler strains of Campylobacter jejuni were determined in broiler chicks aged 2-3 days and 2 weeks. Individually housed chicks were exposed to a single oral or cloacal challenge. Diarrhoeal symptoms were absent in all 380 chicks included in the study. Chick susceptibility to the two C. jejuni strains varied. Colonization was effected by less than 10(2)-10(4) colony forming units (c.f.u.) via cloacal challenge and 10(4)-10(6) c.f.u. via the oral route. Colonization inocula for 2- to 3-day and 2-week-old chicks were similar. Treatment of 1-day-old chicks with fresh adult caecal flora or an anaerobic broth culture of adult caecal flora did not inhibit colonization after challenge with low-dose C. jejuni. Susceptible chicks were colonized rapidly. C. jejuni was detected in 167 of 189 (88%) colonized chicks within 3 days of challenge and persisted during the 2-week monitoring period. Our data suggest that colonization of broiler chicks with C. jejuni is effected more easily by the cloacal than the oral route and is independent of age.     

Campylobacter jejuni enteritis mistaken for ulcerative colitis.

Campylobacter jejuni is the most common bacterial cause of gastroenteritis and is often missed by routine stool cultures. Patients may present with a clinical syndrome and endoscopic findings that are similar to acute ulcerative colitis. Ciprofloxacin is currently the recommended antibiotic therapy.     

Campylobacter jejuni enteritis associated with raw goat's milk

During a three-week period in July 1983, six cases of Campylobacter jejuni enteritis in King County, Washington were associated with a dairy that produced raw goat's milk. Four patients consumed the dairy's milk, and the other two patients comprised an employee of the dairy and her infant son. Two case-control studies confirmed that, at the time the cases occurred, consumption of the dairy's milk was a risk factor for C. jejuni enteritis in King County. C. jejuni was isolated from the intestinal tract of three of the dairy's goats. Two of the three isolates, as well as those from five of the patients (all of those tested), were Lior serotype 36. That serotype was not encountered among 14 other C. jejuni isolates from King County during the period of the outbreak, including three isolates from goats at another inspected dairy. The study shows that raw goat's milk may transmit C. jejuni infection from animals to humans, as other investigators have shown for unpasteurized cow's milk.     

Evaluation of flagellum-related proteins FliD and FspA as subunit vaccines against Campylobacter jejuni colonisation in chickens

Campylobacter is the leading cause of food-borne diarrhoea in humans in the developed world and consumption of contaminated poultry meat is the main source of infection. Vaccination of broilers could reduce carcass contamination and zoonotic infections. Towards this aim, we evaluated recombinant anti-Campylobacter subunit vaccines based on the flagellum-capping protein FliD and the flagellum-secreted protein FspA as they are immunogenic in chickens and the flagellum is vital for colonisation. In three studies, a recombinant FliD vaccine induced a transient but reproducible and statistically significant decrease of c. 2 log₁₀ CFU/g in caecal colonisation levels at 49 days post-primary vaccination on the day of hatch. Levels of serum IgY specific to FliD positively correlated with caecal bacterial counts in individual birds, indicating that such antibodies may not play a role in protection. The data add to the limited repertoire of candidate antigens for the control of a key foodborne zoonosis.     

Experimental infection of the bovine udder with Campylobacter coli/jejuni.

Five quarters of the udders of two lactating cows were infected by intramammary inoculation with Campylobacter coli/jejuni in doses ranging from 2.6 colony-forming units (c.f.u.) to 3.8 X 10(9) c.f.u. The infected quarters developed clinical mastitis and the campylobacters were reisolated in large numbers from the milk. The milk from the uninfected quarters, and blood and faeces remained free of the organisms. The campylobacters could only be isolated by incubation of culture plates in a microaerobic atmosphere. The results showed that C. coli/jejuni can cause mastitis in the cow and that the bovine udder is a potential source of C. coli/jejuni in raw milk.     

The protection of infant mice from colonization with Campylobacter jejuni by vaccination of the dams.

Intraperitoneal vaccination of female mice, before mating, with a whole cell, heat-killed (62 degrees C) vaccine of Campylobacter jejuni allowed the mother to confer immunity to her young, challenged orally 4-6 days after birth with the homologous strain. There was no protection against a strain of another serotype. Heating the vaccine to 100 degrees C destroyed its protective properties. A vaccine prepared from an aflagellate variant of the original strain was as protective as the original vaccine against challenge with the flagellated strain. Anti-flagellar serum antibody titres of the dams did not correlate with protection of their young.