RESUMO
The diversity and genetic interrelation of Campylobacter jejuni and C. coli isolated from Swiss poultry were assessed by three independent typing methods. Samples were derived prior to slaughter from 100 randomly selected flocks (five birds per flock) raised on three different farm types. The observed flock prevalence was 54% in total, with 50% for conventional and 69% for free-range farms. Birds held on farms with a confined roaming area had the lowest prevalence of 37%. Campylobacter isolates were characterized by amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism of flaA PCR fragments (flaA-RFLP), and disk diffusion testing for eight antimicrobial agents that are commonly used in veterinary or human medicine in Switzerland. Analysis of the genotypic results indicates that the Campylobacter population in Swiss poultry is genetically highly diverse. Nevertheless, occasionally, isolates with identical or nearly identical characteristics were isolated from different farms or farm types in different locations. Genetic typing by AFLP and flaA-RFLP was found to be complementary. The majority of isolates (67%) were susceptible to all tested antibiotics; however, single, double, and triple resistances were observed in 7%, 23%, and 2% of the strains, respectively. There was no correlation between genotype and antibiotic resistance. Surprisingly, sulfonamide resistance was frequently found together with streptomycin resistance. Our findings illustrate the results of common genetic exchange in the studied bacterial population.
Assuntos
Campylobacter coli/classificação , Campylobacter jejuni/classificação , Farmacorresistência Bacteriana , Variação Genética , Doenças das Aves Domésticas/epidemiologia , Criação de Animais Domésticos , Animais , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Infecções por Campylobacter/veterinária , Campylobacter coli/efeitos dos fármacos , Campylobacter coli/genética , Campylobacter coli/isolamento & purificação , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/genética , Campylobacter jejuni/isolamento & purificação , Galinhas/microbiologia , Flagelina/genética , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Doenças das Aves Domésticas/microbiologia , Prevalência , Suíça/epidemiologiaRESUMO
Efficiency of animal waste sterilization prescribed by the European Union and Switzerland was verified using a pork-based ELISA and two PCR assays (tRNA(Glu)/cytochrome b specific for vertebrates; bovine species-specific cytochrome b mitochondrial genome). A total of 204 samples of feedingstuffs were analysed including reference materials subjected to known heat treatments. Both ELISA and PCR assays were able to detect poorly heat-treated feedingstuffs if there was enough pork-based material present. The proposed species-specific PCR test, however, showed a higher sensitivity and specificity as it specifically detected bovine material. Nevertheless, the PCR assay will not detect bovine material in properly heat-treated feeds as the DNA is too fragmented. It is, however, very useful as a rapid, sensitive, and specific method for the routine screening of animal meals with regard to prophylaxis of BSE.
