The prevalence of antibiotic-resistant faecalEscherichia coli in healthy volunteers in Venezuela

Faecal samples were collected from healthy volunteers in two regions in Venezuela, the village of Grulla (n=195) and the city of Mérida (n=181), and analysed for the prevalence of antibiotic resistant faecalEscherichia coli as well as the antibiotic susceptibility of the strains isolated. The highest prevalences of resistance were observed for amoxicillin, oxytetracycline, sulfamethoxazole and trimethoprim. The percentages found for Grulla were 46, 38, 44 and 30%, respectively; for Mérida 39, 65, 56 and 36%, respectively. In Mérida, a significantly higher prevalence of resistance for oxytetracycline was found (P<0.05). Significant differences in the distribution of the MIC values between Grulla and Mérida were observed for amoxicillin, chloramphenicol and oxytetracycline (P<0.05). In Grulla, the most frequent pattern was resistance to amoxicillin only and in Mérida to oxytetracycline only. Amoxicillin resistance was due to production of TEM1 β-lactamase.