Advanced Studies on Salmonellosis in Sheep and Goats

Abstract

This study was conducted to assess the frequency of salmonellosis occurrence in diarrheic sheep and goats raised in mixed reared flocks in Giza governorate in Egypt, identifying the management factors associated with perpetuation of Salmonella spp. pathogen among diarrheic animals in the investigated flocks, investigate role of enterotoxin (Stn) gene in development of diarrhea, and investigate different antimicrobial alternatives to control salmonellosis. A total number of 518 rectal swabs were collected from 325 diarrheic sheep and 193 diarrheic goats belonged to seven mixed reared flocks in Giza governorate, Egypt. A systematic approach was used to evaluate and identify the factors associated with disease occurrence in the investigated flocks. Bacteriological examination of samples using conventional methods for isolation of Salmonella spp. showed the prevalence was 4% (13/325) in diarrheic sheep and 3.63% (7/193) in diarrheic goats, and the overall prevalence in diarrheic sheep and goats was 3.86% (20/518). The point prevalence in different flocks were 7.55%, 4.21%, 0, 4.05%, 5.26%, 0% and 0% in flocks 1, 2, 3, 4, 5, 6 and 7, respectively. Serotyping of 20 Salmonella spp. isolates using slide agglutination tests evidenced different serotypes, and their prevalence was 1.93% for S. Mississippi, 0.39% for each of S. Durham and S. Enteritidis, and 0.19% for each of S. Ferruch, S. Paratyphi A, S. Allerton, S. Bonariensis, S. Kottbus, and S. Stanleyville. The phenotypic antimicrobial sensitivity pattern of the recovered strains to 10 antimicrobials was evaluated by both minimum inhibitory concentration (MIC) and disc diffusion methods. Regarding MIC method results, all isolates were resistant to colistin, doxycycline, and oxytetracycline and all were sensitive to amikacin and enrofloxacin, and moreover, showed variable patterns to the other 5 antimicrobials. The resistance rates were 95%, 70%, 60%, 15% and 5% for sulfamethoxazole-trimethoprim, amoxicillin, ciprofloxacin, florfenicol and gentamycin, respectively. All 20 isolates had an index range of 0.4–0.7, which identified as MDR Salmonella spp.,