OCCURENCE AND ANTIBIOGRAM OF SALMONELLA SPP. IN RAW AND FERMENTED MILK IN ZARIA AND ENVIRONS

Abstract

Salmonellosis is an important food-borne disease affecting both humans and animals. The aim of this study was to determine the occurrence and antibiogram of Salmonella species from raw and fermented milk. The results showed that out of the 350 milk samples examined 14 (4.0%) were positive for salmonella. The prevalence of Salmonella is higher in raw milk (4.6%) than in fermented milk (3.4%) with no statistical difference (P>0.05) between them. The prevalence of both raw (75.0%) and fermented milk (83.33%) is significantly higher (P<0.05) in SabonGari LGA than in Giwa LGA with 25.0% and 16.67% respectively. No salmonella was isolated from the all the 50 raw and 78 fermented milk examined from Zaria LGA. The antibiotic susceptibility test showed that ciprofloxacin and gentamicin were 100% susceptible, while chloramphenicol, kanamycin, nalidixic acid showed 93% susceptible each. Others are streptomycin and tetracycline (64.3%), amoxicillin (21.4%), ampicillin and erythromycin (14.3%) and lincomycin (0%). This connotes that all the Salmonella isolates were 100% resistance to lincomycin, 85.7% to erythromycin, 85.7% to ampicillin and 78.6% to amoxicillin. The antibiotic resistance pattern of 14 Salmonella isolates from raw and fermented milk showed 9 different resistance patterns of the11 antimicrobial agents used. The Minimum Inhibitory Concentration (MIC) test showed that only 1(7.1%) of the isolate was sensitive to Amoxicillin with < 0.12 while the remaining 9 (98.9%) were resistant to the two antibiotics used (AML and E) with >256.