Date of Award

1988

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biomedical and Veterinary Medical Sciences - Veterinary Clinical Sciences

First Advisor

Simon M. Shane

Abstract

A study was conducted to determine the prevalence of Campylobacter jejuni in various avian species and humans. Cloacal swabs derived from birds submitted to the Louisiana Veterinary Medical Diagnostic Laboratory for necropsy examination during the period February 1987 through July 1988 were routinely cultured for C. jejuni using Butzler's selective medium. Campylobacter jejuni was isolated from 10.1% of the cases examined. The isolation rate was 25.2% in Galliformes, 12.9% in Anseriformes, 8.3% in Columbiformes, 7.7% in Falconiformes, and 0.6% in Psittaciformes. None of the other orders of birds examined yielded C. jejuni. Prevalence data demonstrated that Galliformes are important reservoirs of C. jejuni infection for humans and that Psittacines do not represent any significant risk to human contacts. Prevalence of C. jejuni in diarrheic patients was studied during a one-year period, from August 1987 through July 1988. Of a total 1423 fecal samples cultured, 38 yielded C. jejuni giving an isolation rate of 2.7%. This is comparable to the 2.6% prevalence rate obtained in a similar study in Texas. Prevalence rate for Salmonella spp. during the same study was 2.0%. Seasonal fluctuation in prevalence of C. jejuni in humans was demonstrated, with a peak in Summer and a smaller increase in Winter. A high incidence was observed in children under 5 years, and in adults aged 21 to 25 and 31 to 40 years. The Penner serotyping system was able to classify 91.1% of the isolates obtained from human patients and 96.7% from avian species. Fourteen of the 16 serotypes considered in the present study were identified among the isolates. Eight of the serotypes were common to both avian species and humans indicating the potential for zoonotic transmission of C. jejuni infection from birds. Serotype Penner 1 was isolated only from avian species indicating the low risk this serotype poses for humans while serotype Penner 10 was isolated mainly from humans suggesting that this serotype is transmitted by direct contact or acquired from non-avian species. Two serotypes (Penner 5 and 10) showed consistent production of enterotoxins. Toxin was produced by 75% of human and 85% of avian isolates demonstrating the considerable potential for human infection with toxigenic strains of C. jejuni.

Pages

173

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