Domestic poultry is a natural reservoir of Campylobacter, the host–pathogen interaction being predominantly asymptomatic. This study investigated whether chickens remain asymptomatic partly because of lactic acid bacteria (LAB).

Introduction: Campylobacter jejuni is one of the most frequently reported causes of foodborne bacterial enteric disease worldwide. The main source of these microorganisms is contaminated food, especially of poultry origin. There are several molecular methods for differentiation of Campylobacter isolates at the subgenus level, and one of these is porA-typing based on the sequencing of the major outer-membrane protein (MOMP) encoding gene. The aim of the study was to test the molecular relationship of C. jejuni strains isolated at different points along the poultry food chain and assess the population structure of the isolates. Material and Methods: A total of 451 C. jejuni were used in the study, and a DNA fragment of 630 bp of the MOMP encoding gene was amplified and sequenced. Results: One hundred and ten sequence types were identified, with 69 (62.7%) unique to the isolates' origin and 30 not present in the database. The most prevalent nucleotide variant 1 was detected in 37 (8.2%) strains. These isolates were identified in all poultry sources tested, especially in faeces (15 isolates) but also in poultry carcasses and meat (11 isolates in each). Conclusion: The porA typing method was highly discriminative for C. jejuni of poultry origin since the Simpson's diversity index (D) achieved a value of 0.876, indicating considerable diversity in the bacterial population tested. The method may be further used for epidemiological investigation purposes.

Introduction:Campylobacter jejuni is one of the most frequently reported causes of foodborne bacterial enteric disease worldwide. The main source of these microorganisms is contaminated food, especially of poultry origin. There are several molecular methods for differentiation of Campylobacter isolates at the subgenus level, and one of these is porA-typing based on the sequencing of the major outer-membrane protein (MOMP) encoding gene. The aim of the study was to test the molecular relationship of C. jejuni strains isolated at different points along the poultry food chain and assess the population structure of the isolates.

Domestic poultry is a natural reservoir of Campylobacter, the host–pathogen interaction being predominantly asymptomatic. This study investigated whether chickens remain asymptomatic partly because of lactic acid bacteria (LAB). Campylobacter spp. and LAB were isolated from the gut of poultry chickens using enrichment and screening assays and were identified via rDNA sequencing. The C. jejuni DC3 isolate was grown in different cell-free supernatants (CFS) generated from a priority LAB isolate. An in vivo challenge involving the C. jejuni and LAB isolates using a chicken model was performed to confirm the in vitro findings. Twelve presumptive LAB isolates had anti-C. jejuni activity based on cross-streak and agar plug assays, with Lactobacillus sakei L14 isolate exhibiting the highest activity. Inhibition by L. sakei L14 CFS of the growth of C. jejuni occurred in a dose-dependent manner. Campylobacter jejuni DC3 inhibition was most evident in CFS harvested at 72 h and produced by co-culture with the pathogen. Neutralisation of the CFS abrogated the observed inhibition. Co-infection with C. jejuni DC3 and L. sakei L14 in vivo, however, failed to inhibit C. jejuni colonisation in chickens. The results suggest that the anti-C. jejuni effect of L. sakei L14 in chickens may be due to mechanisms other than direct inhibition of growth.

Objective-To compare efficacy of 2 commercial ovine Campylobacter vaccines and an experimental bacterin in guinea pigs following IP inoculation with Campylobacter jejuni IA3902. Animals-51 female guinea pigs. Procedures-Pregnant and nonpregnant animals were randomly assigned to 1 of 4 treatment groups and administered a commercial Campylobacter vaccine labeled for prevention of campylobacteriosis in sheep via two 5-mL doses 14 days apart (vaccine A; n = 13), another labeled for prevention of campylobacteriosis via two 2-mL doses (vaccine B; 12), an experimental bacterin prepared from the challenge strain (12), or a sham vaccine (14). Ten days later, animals were challenged IP with C jejuni IA3902; 48 hours later, animals were euthanized, complete necropsy was performed, and blood and tissue samples were obtained for bacteriologic culture. Results-Administration of vaccine B or the experimental bacterin, but not vaccine A, significantly reduced 48-hour infection rates versus administration of the sham vaccine. A significantly reduced 48-hour infection rate was associated with administration of vaccine B independent of pregnancy status. Conclusions and Clinical Relevance-Administration of vaccine B significantly reduced infection in guinea pigs challenged with C jejuni IA3902, similar to a homologous bacterin. Results suggested that vaccine B or an autogenous product may be effective in controlling ovine campylobacteriosis caused by this emergent abortifacient strain. Bacteriologic culture of blood, liver, bile, and uterus in nonpregnant guinea pigs 48 hours after inoculation may be a useful screening tool for comparing efficacy of C jejuni vaccines.

Rectal swab specimens were collected from 362 apparently healthy dogs of different origin, age, breed, and sex. Specimens were obtained in summer, autumn, and winter. Ninety-five thermophilic Campylobacter spp were isolated: C jejuni biotype I, n = 57, C jejuni biotype II, n = 1, C coli, n = 36, and C laridis, n = 1. Biotypes of C jejuni recovered were the same as those associated with Campylobacter-induced enteritis in human beings. Prevalence of C jejuni was significantly (P < 0.05) greater: in dogs < 6 months old than in adult dogs; in dogs living under high density and cohabitation housing conditions for long periods; and in autumn.

Forty 3- to 17-week old domestic ferrets, including 2 gnotobiotes, were inoculated orally and/or rectally with 10(6), to 10(9) colony-forming units of 1 or more of 4 strains of Campylobacter jejuni, 3 of mink and 1 of human origin. Feeding or gavage of any of the 4 strains, in milk or broth, with or without preinoculation sodium bicarbonate treatment to neutralize stomach acid, induced colonization in 38/40 ferrets; diarrhea lasted 2 to 4 days in conventional kits, 6 days in gnotobiotes. Bacteremia was detected in 4 of 18 tested, 2 to 5 days after inoculation. Two strains caused no more severe disease or prolonged colonization after 3 serial IV passages in kits than they did before passage. Multiple inoculations with a given strain resulted in progressively briefer colonization and milder disease, but subsequent inoculation with a different strain induced colonization and gastrointestinal disease similar to a primary infection. Five kits inoculated rectally after 4 previous homologous inoculations were resistant to colonization as well as to disease. Agglutinin titers of ferrets inoculated orally or rectally once were low or undetectable, but increased in response to repeated inoculation. Pretreatment with a 1% formalin enema caused mild colon irritation without clinical or histologic evidence of proliferative colitis in ferrets concurrently inoculated orally and/or rectally, whether or not they had preexisting antibodies to any strain of C jejuni. Histologic examination of tissues revealed leukocytic infiltration of intestinal lamina propria in 29 of 35 infected kits and 5 of 8 noninfected controls, and cryptosporidiosis in 5 infected kits plus 1 control. Examination of silver-stained sections of intestine from 15 infected ferrets revealed Campylobacter-like organisms on the surface of, but never inside, epithelial cells. The lack of characteristic gross or histologic lesions suggested that C jejuni is not, by itself, responsible for proliferative colitis in ferrets.

Twenty-four isolates representing 6 species of Campylobacter were screened for plasmids. A large plasmid with an approximate molecular weight of 38 Mdal was detected in 5 C jejuni isolates originally recovered from diarrheic human beings, in one isolate of C coli recovered from diarrheic pigs, and in 1 isolate of C sputorum ssp mucosalis and 2 isolates of C hyointestinalis recovered from pigs with proliferative enteritis. One isolate of C coli and 1 isolate of C hyointestinalis contained an additional smaller plasmid with an approximate molecular weight of 1.6 Mdal; this plasmid was partially mapped by restriction endonuclease digestion. Fifteen Campylobacter isolates contained no detectable plasmids: 2 C coli, 2 C sputorum ssp mucosalis, 2 C fecalis, 1 C fetus ssp fetus, and 8 C hyointestinalis isolates. In summary, 37.5% of the Campylobacter isolates contained a 38-Mdal plasmid, with 8% having both 38 Mdal and 1.6-Mdal plasmids; 62.5% contained no detectable plasmids.

OBJECTIVE To evaluate the efficacy of tulathromycin for prevention of abortion in pregnant ewes when administered within 24 hours after experimental inoculation with Campylobacter jejuni. ANIMALS 20 pregnant ewes between 72 and 92 days of gestation. PROCEDURES All ewes were inoculated with a field strain of C jejuni (8.5 × 108 to 10.6 × 108 CFUs, IV). Eighteen hours later, ewes received either tulathromycin (1.1 mL/45 kg [2.4 mg/kg], SC; n = 10) or sterile saline (0.9% NaCl) solution (1.1 mL/45 kg, SC; sham; 10). Ewes were euthanized immediately after observation of vaginal bleeding, abortion, or completion of a 21-day observation period. Necropsy was performed on all ewes, and tissue specimens were obtained for bacterial culture and histologic examination. RESULTS 1 sham-treated ewe and 1 tulathromycin-treated ewe developed signs of severe endotoxemia and were euthanized within 24 hours after C jejuni inoculation. Seven sham-treated and 2 tulathromycin-treated ewes developed vaginal bleeding or aborted and were euthanized between 4 and 21 days after C jejuni inoculation. The proportion of tulathromycin-treated ewes that developed vaginal bleeding or aborted during the 21 days after C jejuni inoculation (2/9) was significantly less than that for the sham-treated ewes (7/9). CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that administration of tulathromycin to pregnant ewes following exposure to C jejuni was effective in decreasing the number of C jejuni–induced abortions. Because of concerns regarding the development of macrolide resistance among Campylobacter strains, prophylactic use of tulathromycin in sheep is not recommended.

Feral pigeons (Columbia livia) can harbor a range of zoonotic pathogens. A transversal study was undertaken to estimate the prevalence of feral pigeons infected by various pathogens in public areas in Montreal, Quebec. Cloacal swabs from captured birds were cultured for Salmonella spp. and Campylobacter spp. and tested by real-time polymerase chain reaction (RT-PCR) for the detection of Coxiella burnetii. An oropharyngeal swab was also submitted to real-time reverse-transcription polymerase chain reaction (RRT-PCR) for the detection of Newcastle disease virus. Among the 187 pigeons tested from 10 public areas, 9.1% (95% CI: 3.0 to 15.2) were positive for Campylobacter spp. with all strains identified as Campylobacter jejuni. The Campylobacter status of birds was not associated with individual characteristics of birds, with the exception of body score. None of the pigeons tested positive for the other pathogens. Direct or indirect contacts with feral pigeons may constitute a potential risk for Campylobacter infection in humans.