Distribution and antimicrobial resistance of Salmonella serotypes in minced beef, calves and humans in Bishoftu and Addis Ababa, Ethiopia

Abstract

This study was conducted to determine the prevalence and antimicrobial profile of Salmonella in 102 beef, 384 stool and 107 calf faecal samples. The beef samples were collected from 34 randomly selected supermarkets in Addis Ababa, stool samples were collected from Bishoftu General Hospital and calf faecal samples were from randomly selected dairy farms in Bishoftu. Of the total 102 minced beef, 384 stool and 107 faecal samples examined, 9.8, 3.4 and 1.9%, respectively, were positive for Salmonella. Twenty-five Salmonella isolates comprising of 14 different serotypes were identified. Among the different serotypes, S. Typhimurium was predominant (28%) followed by S. Uganda (20%) and S. Bovismorbificans (8%). The other serotypes identified were S. Anatum, S. Blockley, S. Braenderup, S. Enteritidis, S. Hadar, S. Havana, S. Livingstone, S. Mikawasima, S. Muenchen, S. Saintpaul and S. Typhimurium var. Copenhagen totally comprising 44%. Salmonella Mikawasima was reported for the first time in Ethiopia. Assay of antimicrobial resistance revealed that 20% of the isolates were resistant to three or more of the 24 antimicrobials checked. Resistance to 15 antimicrobials was recognized. The most common resistance was to nitrofurantion, streptomycin and tetracycline. Most of the antimicrobial resistant Salmonella isolates were from the meat samples. Result of the present study indicate that Salmonella isolates are diverse in serotype with significant antimicrobial resistance in the samples tested which could be potential sources of drug resistant Salmonella infections. Key words: Addis Ababa, Bishoftu, calf, Ethiopia, human, minced beef, Salmonella.