Abstract:
Two hundred and twenty specimens from diseased and freshly dead chickens gathered under complete aseptic conditions and transported to the laboratory of Faculty of Veterinary Medicine-Assiut University. Samples were processed for bacteriological and biochemical examinations; suspected Salmonella isolates were serologically identified. Standard disc diffusion technique was used for antibacterial sensitivity testing of the isolated Salmonella.
Minimum antibacterial inhibitory concentration (MIC) was also determined.
11.36% (25/220) out of the examined chicken samples were infected with Salmonella. The infection was more prevalent in two-weeks old chickens (20%) than 4weeks-old (5%). Salmonella was frequent in liver and spleen (13.33%, 11.26%, respectively) than caecum and yolk sac (9.3%, 6.25%, respectively). The isolated Salmonellae were serotyped as S. Kentucky (27.77%), S. Enteritidis (22.22%), S. Typhimurium (16.66%), S. Molade (11.11%), while S. Inganda, S. Papuana, S. Wingrove and S. Larochelle encountered in the same percent (5.55%). These obtained isolates exhibited complete antibacterial resistance to amoxicillin and ampicillin (100%), but (88.88%) resistance to cefotaxime and oxytetracycline, (83.33%) to erythromycin, (72.22%) to doxycycline, (66.66%) to neomycin and (61.11%) resistance to amikacin. Somewhat, antibacterial sensitivity was noticed to colistin (55.55%), spectinomycin (44.44%) and norfloxacin (33.33%). Based on MIC, colistin and florfenicol were the most sensitive antibacterial at a lower MIC value (<2μg/ml).