Assessment of multidrug-resistant phenotypes and detection of ampicillin-resistant determinants among Escherichia coli isolates of groundwater origin: case study—Osogbo, Southwest Nigeria

摘要

Abstract Multidrug resistance in groundwater contaminants is becoming a major health concern in developing countries, especially the ampicillin-resistant Escherichia coli. This study aimed at profiling antibiotic resistance and possible detection of ampicillin-resistant genes in Escherichia coli obtained from forty groundwater samples (20 each of boreholes and wells) in Osogbo metropolis, Southwest Nigeria. Grab sampling was done using 1L sterile plastic bottles, isolation of E. coli was performed using pour plate technique on eosin methylene blue agar and their identity confirmed by polymerase chain reaction (PCR) using uidA gene. Antibiotics susceptibility test of the isolates to ten commercially available antibiotics was done following Kirby–Bauer disc diffusion technique. Multiple antibiotic resistant phenotypes (MARPs) and indexing (MARI) were estimated accordingly. The possible presence of Ctx-M, SHV, ampC, and TEM-H resistant genes in all ampicillin-resistant E. coli were checked for using PCR. All the 55 presumptive E. coli isolates, 35 from 10 boreholes and 20 from 7 wells, were uidA positive. Overall, 50 (91) of the E. coli were resistant to ampicillin, followed by trimethoprim and ertapenem 43 (78), doxycycline 40 (73), ceftazidime 38 (69), and tetracycline 37 (67). Of the 55 E. coli isolates, only 1 was resistant to 2 drugs (AK-AMP), others were multi-resistant, ranging from 4 to 9 drugs, with the highest MARP (9) being AMP–CAZ–ETP–S–AK–DO–TE–W–C. MARI also between 0.4 and 0.9, above the 0.2 acceptable limit. Exactly 24 (48) of the phenotypically ampicillin-resistant E. coli isolates harboured TEM-H only. The existence of multidrug-resistant E. coli and TEM-H resistant?gene in the groundwater pose a huge threat to all and sundry who rely heavily on this source of water for diverse?purposes. Hence, adequate monitoring and antimicrobial resistance?surveillance of?groundwater bodies is advocated to safeguard public health.