Antimicrobial susceptibility of non-sorbitol fermenting Escherichia coli isolated from cattle feaces and milk samples

Abstract

The objective was to determine the antimicrobial susceptibility of the non-sorbitol fermenting Escherichia coli colonies from cattle feaces and milk samples collected from Dagoretti division in Nairobi. A total of 285 feacal and 260 milk were collected from urban dairy farming households while non-dairy households provided 137 milk samples. The samples were used for culture and isolation of E. coli and the colonies isolated using standard microbiological methods. 23% (66) and 8.8% (23) of feacal and milk samples from urban dairy farming households had non sorbitol fermenting colonies, while 8.8% (12) of non-dairy farming household neighbours had non sorbitol fermenting colonies in milk samples. Antibiotic susceptibility patterns showed that isolates of E. coli were resistant to various antibiotics. There was a high percentage resistance to sulphamethoxazole in feacal samples isolates (14.4%), milk sample isolates (10%) from dairy farming household and milk sample isolates (11.7%) nondairy households. The feacal isolates had a low resistance to ampicilin (1.4%), but the resistance in isolates from milk samples of urban dairy household (6.5%) and non-dairy household’s milk samples (7.3%) were high. The other antibiotics showed varied resistance pattern with feacal isolates having a high percentage resistance to tetracyclines (6.7%) while most bacterial isolates were susceptible to gentamicin. Multiple antibiotic resistances was observed in feacal sample isolates (6.7%), dairy farming household milk isolates (4.2%) and non- dairy farming household milk isolates (7.3%). Non-sorbitol fermenting E. coli colonies from cattle feaces and milk samples were resistant to most of the antibiotics tested and the higher percentage resistance to sulphamethoxazole, ampicilin and tetracyclines requires further investigation to isolate, identify and compare the genes responsible for development of resistance.