Serotyping and antimicrobial resistance of Salmonella spp. isolated from commercial flocks of laying hens in R. Macedonia

摘要

In the period from October to December 2011, 61 isolates of Salmonella were isolated from flocks of laying hens providing eggs for human consumption. Most of the isolates belonged to the serovars Enteritidis (n=35; 57.38%), Typhimurium (n=17; 27.87%) and other (n=9; 14.75%). These isolates were tested for antimicrobial resistance to ampicillin, cefotaxime, chloramphenicol, ciprofloxacin, nalidixic acid, sulfamethoxazole, tetracycline, gentamicin and streptomycin. All of the tested Salmonella were sensitive to cefotaxime, chloramphenicol and ciprofl oxacin. The highest resistance rate was shown to tetracycline with eight (13,11%) and streptomycin with nine (14,75%) isolates, three (4,92%) isolates were resistant to nalidixic acid, and one isolate (1,63%) exhibited resistance to ampicillin, sulfamethoxazole and gentamicin. Forty four isolates (72,13%) were sensitive to all antimicrobials. i.e. 17 (27,87%) isolates showed resistance to at least one antimicrobial of which 12 isolates showed resistance to one, four isolates showed resistance to two antimicrobials and one isolate showed resistance on three antimicrobials. When results of resistance levels of Salmonella spp. were compared with the offi cial data from the European Union reported by EFSA, it was concluded that the Salmonella spp. isolated from flocks of laying hens providing eggs for human consumption in R. Macedonia have low resistance to antimicrobial drugs.