Résumé:
This study determined the prevalence of pathogenic enterobacteria and identified the main risk factors, in farms, slaughterhouses and butcheries in eastern Algeria, during a twoyear period. Thus, a crosssectional study was conducted, using a simple random sampling method to target 20 farms, 10 slaughterhouses and 5 butcheries. A structured questionnaire was used to assess the hygienic status of the farms, slaughterhouses and butcheries. In addition, 265 samples were collected from walls, soil, litter, feed, water and animal samples consisting mainly of white and red meat, neck skin and liver.
aerobic microbial count, Enterobacteriaceae, fecal coliforms and Salmonella were enumerated and selected colonies were identified on the basis of biochemical characteristics and confirmed by MALDI TOF.
On the other hand, in order to investigate the use of antibiotics by veterinarians in Algeria, a prospective survey was conducted through a questionnaire. In addition, fifteen antibiotics (15) were used to evaluate the sensitivity of the identified bacteria (n=82). Multiresistant strains (MDR) were tested for resistance genes to betalactams, sulfonamides and quinolones by PCR.
The results showed that the prevalence of Enterobacteriaceae is 68.68%. While the prevalence of Escherichia coli and Salmonella spp. is 57.69% and 19.23% respectively. The highest contamination rate was in poultry farms (30.77%), red meat slaughterhouses (18.13%), white meat slaughterhouses (15.38%) and butcher shops (14.84%), followed by beef (13.19%) and sheep (7.69%), farms.
The results of the questionnaire showed that the antibiotics often used in cattle and sheep farms are ß lactams, sulfonamides and tetracyclines. In contrast, in poultry farms, sulfonamides, quinolones and colistin are the most prescribed antibiotics. While the results of the antibiogram recorded an overall resistance rate of enterobacteria strains of 77.92% (60/77). The observed resistance rates showed high levels for amoxicillinclavulanic acid, oxytetracycline and trimethoprimsulfonamides. Low levels of resistance were noted for fosfomycin, colistin and gentamicin. Furthermore, for betalactams, our results showed that 3.03% of multiresistant enterobacteria carry the CMY-2 gene. On the other hand, for sulfonamides, 50% carry the Sul1 gene, 75% the Sul2 gene, and 25% the Sul3 gene. Moreover, for quinolones, no strain was positive.
This study highlighted the multifactorial effects of pathogenic enterobacteria contamination on farms such as animal density, hygiene and litter scraping, manure storage, water, pest control, contact with other animals, and the decontamination process. Overall, these results indicate a high rate of contamination and antibiotic resistance by enterobacteria in the food chain.
Further studies are needed to determine all potential risk factors associated with contamination and transmission of antibiotic resistance in order to assess the remedial effects of these factors. Thus, the establishment of surveillance and control systems could also help to improve the quality of products intended for human consumption and to preserve public health.
