Résumé
The present investigation showed that the incidence of salmonellae in sheep and lambs was [4.49%] and [9.18%] respectively. The incidence in sheep differed according to age and health conditions as it was higher in lamb than in adult and in diseased than apparently healthy as it was [12.73%] and [4.65%] in diseased and apparently healthy lambs. Meanwhile, it was [6.67%] and [3.39%] in diseased and apparently healthy adults sheep respectively. The prevalence of salmonellae in slaughtered sheep was [4.44%] and it was higher in intestines [6.67%] than in livers and lymph nodes [3.33%] each. The prevalence of salmonellae in dead lambs was [11.76%] and this incidence was similar in the examined livers, intestines and lymph nodes [11.76%] each. The incidences in feedstuffs, water, soil, waste samples and swabs from workers' hands in environment of living sheep, lambs and dead lambs were [5.71%, 2.86%, 8.57%, 22.22% and 11.11%] respectively. While, the incidences from drain water, swabs from walls and workers' hands in environment of slaughtered sheep were [10%, 12.5% and 6.67%] respectively. The isolated salmonellae were belonged to 7 serovars and S. Typhimurium was most predominant isolate. Also S. Arizonae, S. Cerro, S. Enteritidis, S. Ferruch, S. Montevideo and S. Sandiego were isolated. S. Arizonae, S. Ferruch, S. Montevido, S. Sandiego and S. Typhimurium harboured the virulence associated gene. While, S. Cerro, S. Enteritidis, S. Typhimurium [from slaughtered sheep] didn't harbour this gene. S. Arizonae, S. Cerro, and S. Ferruch yielded [100%] mortality rate in each, followed by S. Sandiego [80%] then S. Typhimurium, S. Typhimurium [from slaughtered sheep] and S. Enteritidis [60%] each, while S. Montevideo yielded lower mortality rate [40%]. It was clear that [95.24%] of the isolates were susceptible to ciprofloxacin and enrofloxacin then, [90.48%], were susceptible to flumequine and [83.33%] were susceptible to amikacin. On the other hand the lower susceptibility incidences were observed to streptomycin [19.05%] and cefadroxil [23.81%]. Enrofloxacin gave the highest inhibitory effect as its MIC was 0.195-312 micro g/ml for sensitive isolates followed by ciprofloxacin and flumequine with MIC: 0.39-3.12 micro g/ml for sensitive isolates while chloramphenical gave the lowest effect on the isolates as its MIC was 3.12-12.5 micro g/ml for sensitive isolates