Histopathology and Spatial Distribution of Putative Growth Factors in Relation to Bacterial Localization of Campylobacter jejuni Within the Ovine Gallbladder.

Campylobacter jejuni is an important zoonotic pathogen that is the leading cause of both human foodborne bacterial gastroenteritis worldwide and ovine abortion in the United States. Previous studies have demonstrated that the gallbladder of ruminants is often positive on culture for Campylobacter sp., suggesting that this environment may serve as a chronic nidus of infection for maintenance of disease within populations. The objective of this study was to determine if previously identified putative growth promoting factors of C. jejuni are present within the gallbladder mucosa of sheep and to evaluate for bacterial co-localization of C. jejuni with these compounds following experimental inoculation. Direct gallbladder inoculation with C. jejuni sheep abortion (SA) clone clinical isolate IA3902 followed by immunohistochemical analysis and scanning electron microscopy allowed for identification of C. jejuni at the gallbladder mucosal surface and within the gallbladder submucosal glands. Histochemistry identified several putative Campylobacter growth promoting factors including neutral and acid mucins as well as L-fucose to be present both on the mucosal surface as well as in the gallbladder submucosal glands. In summary, following experimental inoculation of the ovine gallbladder, C. jejuni IA3902 was identified in direct contact with the gallbladder mucosal surface and deep mucosal glands in the same location as several putative growth promoting factors. This suggests the yet to be tested hypothesis that under natural conditions of infection, the gallbladder submucosal glands have the potential to provide a protected niche for chronic carriage of C. jejuni in animal hosts.

Investigating the Suitability of a Laboratory Mouse Model to Study the Pathogenesis of Abortifacient Campylobacter jejuni.

The aim of this study was to assess whether pregnant mice represent a useful model to study the reproductive pathology of Campylobacter jejuni IA3902 using the end point of positive microbial culture of the organism from the fetoplacental unit. Pregnant BALB/c and CD-1 mice (14 days' gestation) were inoculated orally and intraperitoneally (IP) with 1 × 109 colony-forming units/ml of C. jejuni IA3902. The organism was recovered by microbial culture from the fetoplacental unit in 10 of 10 BALB/c and 10 of 10 CD-1 IP-inoculated pregnant mice and in 29% (2/7) BALB/c and 38% (3/8) CD-1 orally inoculated pregnant mice. Gross reproductive lesions included necrosuppurative placentitis, fetal resorption, intrauterine fetal death, stillborn pups (dead neonates), and multifocal hepatitis. Histological changes consisted of locally extensive neutrophilic and necrotizing placentitis with intralesional bacterial colonies of C. jejuni, ulcerative endometritis, random multifocal hepatitis, and rare cholecystitis. Immunohistochemistry for the major outer membrane protein of C. jejuni revealed moderate to large numbers of the organism at the periphery of the placental discs, within trophoblasts and extracellularly, with invasion into the placental disc largely via the vascular network. The organism is trophic for neutral mucin, iron, and L-fucose within the murine placenta. C. jejuni IA3902 has affinity for the murine reproductive tract, specifically the fetoplacental unit, where it results in a necrotizing placentitis with positive microbial recovery after both IP and oral challenge in BALB/c and CD-1 pregnant mice.

Prevalence of antimicrobial residues in table eggs in Trinidad.

The prevalence of antimicrobial residues in pooled table eggs from layer farms, shopping malls, and supermarkets in Trinidad was determined. A total of 23 layer farms and 14 shopping malls were sampled twice, 1 month apart, whereas 102 supermarkets were each sampled once. For each farm, 25 eggs were randomly collected and pooled to constitute a composite sample, whereas six eggs from each farm source available at sale outlets were randomly sampled from malls and supermarkets to constitute a composite sample. Questionnaires were administered at the farms to determine the occurrence of risk factors for contamination of antimicrobial residues in eggs and at sale outlets to determine storage conditions. The Charm II test was used to qualitatively detect antimicrobial residues (beta-lactams, macrolides, sulfonamides, and tetracyclines). Of 46 composite eggs tested from farms, 3 (6.5%) were contaminated with residues compared with 5 (16.1%) of 31 and 16 (15.0%) of 107 mall and supermarket eggs, respectively, but the difference was not statistically significant (P > 0.05). The residues detected were as follows: sulfonamides, 12 (6.5%) of 184; macrolides, 7 (3.8%) of 184; tetracycline, 5 (2.7%) of 184; and beta-lactam, 0 (0.0%) of 184. The difference was statistically significant (P < 0.05). The use of medicated feeds on farm, claim of adherence to the antimicrobial withdrawal period, and temperature of egg storage did not significantly (P > 0.05) affect the prevalence of residues in eggs. It was concluded that the presence of antimicrobial residues, particularly sulfonamides, in table eggs could be of public health significance to the consumer.

Prevalence of antimicrobial residues in table eggs in Trinidad

The prevalence of antimicrobial residues in pooled table eggs from layer farms, shopping malls, and supermarkets in Trinidad was determined. A total of 23 layer farms and 14 shopping malls were sampled twice, 1 month apart, whereas 102 supermarkets were each sampled once. For each farm, 25 eggs were randomly collected and pooled to constitute a composite sample, whereas six eggs from each farm source available at sale outlets were randomly sampled from malls and supermarkets to constitute a composite sample. Questionnaires were administered at the farms to determine the occurrence of risk factors for contamination of antimicrobial residues in eggs and at sale outlets to determine storage conditions. The Charm II test was used to qualitatively detect antimicrobial residues (-lactams, macrolides, sulfonamides, and tetracyclines). Of 46 composite eggs tested from farms, 3 (6.5%) were contaminated with residues compared with 5 (16.1%) of 31 and 16 (15.0%) of 107 mall and supermarket eggs, respectively, but the difference was not statistically significant (P > 0.05). The residues detected were as follows: sulfonamides, 12 (6.5%) of 184; macrolides, 7 (3.8%) of 184; tetracycline, 5 (2.7%) of 184; and -lactam, 0 (0.0%) of 184. The difference was statistically significant (P < 0.05). The use of medicated feeds on farm, claim of adherence to the antimicrobial withdrawal period, and temperature of egg storage did not significantly (P > 0.05) affect the prevalence of residues in eggs. It was concluded that the presence of antimicrobial residues, particularly sulfonamides, in table eggs could be of public health significance to the consumer