Prevalence and distribution of antimicrobial resistance determinants of Escherichia coli isolates obtained from meat in South Africa

Abstract

ObjectiveThis study aimed to characterise antibiotics resistance of Escherichia coli isolates from the formal meat sector (FMS) and informal meat sectors (INMS).\n\nMethodA total of 162 and 102 E. coli isolates from the FMS, and INMS respectively were isolated by standard culture-based, and biochemical reactions. The isolates were further confirmed by polymerase chain reaction (PCR). The disc diffusion method was used to screen for antimicrobial susceptibility against 19 different antibiotics. The presence of class 1-2 integrons in each E. coli isolates was assessed using [Formula] and [Formula] regions specific primers.\n\nResultAmong the 19 antimicrobials, resistance to tetracyclines, aminoglycosides, cephalosporins, and nitrofurans were found to be more frequent than carbapenems and phenicol with a noticeable increase in the number of multi-drug resistance ranging from three to ten antimicrobials. A total of 20 resistance determinants were assessed with their prevalence and distributions obtained as follows for FMS and INMS respectively; [aminoglycosides: aadA (40.6%; 31.9%), aacC2 (21.4%; 31%), aphA1 (20.8%; 15.1%), aphA2 (37.7%; 18.9%) and strA (6.5%; 9.4%)], [{beta}-lactams: ampC (20%; 45%), blaTEM, (4.4%; 13.3), and blaZ (8.9%; 2.2%)], [Chloramphenicol: catI (1.7%; 1.7%), and cmIA1 (1.7%; 1.7%)] and [tetracyclines: tetA (7.7%; 15.4%), tetB (11.5%; 24%), and tetM, (1.9%; 8.7%)], and [sulfonamides: sul1 (22.2%; 26.7%), sul2 (17.8%; 6.7%)].\n\nConclusionMultiple antibiotic resistance (MAR) indexes ranged from 0.2 - 0.5. The results reveal a high prevalence of multidrug-resistant E. coli isolates and resistance determinants suggesting that consumers and handlers of such meat are at risk of contracting antibiotic resistant E. coli-related foodborne disease.