Abstract
BACKGROUND: Additional antimicrobial resistance to extended-spectrum β-lactamase (ESBL)-producing E. coli exhausts treatment options. We investigated allele distribution and resistance to ciprofloxacin and gentamicin among ESBL-producing E. coli isolates from the urine, stool, animals, and environments of presumptive urinary tract infection (UTI) patients, in order to gain a crucial insight toward devising prevention and control measures and treatment guidelines. METHODS: Archived ESBL-producing E. coli isolates from the urine, stool, animals, and surrounding environments of presumptive UTI patients were retrieved. Antimicrobial susceptibility profiles for ciprofloxacin and gentamicin were done followed by multiplex Polymerase chain reaction (PCR) for bla(CTX-M) , bla(TEM) , and bla(SHV) , to determine ESBL allele distribution. Data were analyzed using STATA version 17. RESULTS: A total of 472 confirmed ESBL-producing E. coli isolates from Mwanza 243 (51.5%), Kilimanjaro 143 (30.3%), and Mbeya 86 (18.2%) were analyzed. Of these, 75 (15.9%) were from urine, 199 (42.2%) from stool, 58 (12.3%) from rectal/cloaca swabs of animals, and 140 (29.7%) from surrounding environments. Out of the 472 ESBL-producing E. coli, 98.9% (467) had at least one ESBL allele. The most frequent allele was bla(CTX-M) , which was detected in 88.1% (416/472) of isolates, followed by the bla(TEM) allele, which was detected in 51.5% (243/472) of isolates. A total of 40.7% (192/472) of isolates harbored dual bla(CTX-M) + bla(TEM) alleles and only 0.2% (1/472) of isolates had dual bla(CTX-M) + bla(SHV) alleles, whereas 2.3% (11/472) of isolates had a combination of all three alleles (bla(CTX-M) + bla(TEM) + bla(SHV) ). None of the isolates harbored a combination of bla(TEM) + bla(SHV) only. Resistance to ciprofloxacin and gentamicin was observed in 70.8% (334/472) and 46.0% (217/472) of isolates, respectively. There was a significant difference in the distribution of resistance to ciprofloxacin as well as gentamicin among ESBL-producing E. coli isolated from various sources (p-value < 0.001 and 0.002, respectively). CONCLUSION: Almost all ESBL-producing E. coli isolates carry bla(CTX-M) , bla(TEM) , and bla(SHV) either alone or in combination, with the most common allele being bla(CTX-M.) The resistance to ciprofloxacin and gentamicin, which are frontline antibiotics for UTIs among ESBL-producing E. coli, is high. This implies the need to continually revise the local guidelines used for optimal empirical therapy for UTIs, and for continual research and surveillance using one health approach.