Molecular determination of antimicrobial resistance in Escherichia coli isolated from raw meat in Addis Ababa and Bishoftu, Ethiopia.

Background: Consumption of meat contaminated by E. coli causes a serious illness and even death to affected individuals. Recently the emerging of antibiotic resistant foodborne E. coli poses serious public health risks worldwide. However, little is known about the antibiotic resistance profile of E. coli in Ethiopia. This study aimed to determine the prevalence and Antimicrobial resistance (AMR) status of E. coli isolated from different type of meat.

Methods: Overall 292 samples were collected from December 2015 to April 2016 from slaughterhouses to determine the prevalence and AMR of E. coli isolated from raw beef, mutton, chevon and chicken meat from Addis Ababa and Bishoftu, Ethiopia. The isolates were screened for AMR against commonly used antibiotics circulating in the Ethiopian market. Both phenotypic and genotypic approach were employed for AMR detection using disc diffusion test and PCR respectively.

Results: The prevalence of E. coli was 63 (21.6%), indicating one sample in every five samples harbors E. coli. Among these, the highest E. coli isolates was observed in chicken meat samples (37.0%; 27), followed by mutton (23.3%; 17), chevon (20.6%; 15) and beef (5.5%; 4). Results of disk diffusion test on the 63 isolates showed that only 4.8% of them were not resistance to all antimicrobials tested. Multiple drug resistance (resistance to ≥3 drugs) was 46.0%. Significantly high resistance to ampicillin (71.4%) and tetracycline (47.6%) was observed. Identification of genes associated with AMR was also done using PCR. The prevalence of E. coli isolates harboring resistance gene responsible for tetracycline (tet(A)), beta lactams (blaCMY) and sulphanamide (sulI) antibiotics were found 65.1, 65.1 and 54.0%, respectively. Twenty-five out of the 63 (39.7% %) E. coli isolates have got antimicrobial resistance gene to three or more classes of drugs. The associations of antimicrobial resistance phenotypes and resistance genes was also determined. The detection of resistance trait against tetracycline, sulphametazole and chloramphenicol measured either phenotypically or genotypically were high.

Conclusions: The rising levels of resistance E. coli to multiple antimicrobial dictate the urgent need to regulate and monitor antimicrobial use in both animals and humans.