The evaluation of antimicrobial resistance rates in infections caused by uropathogenic Escherichia coli strains collected from the south of Lebanon

Abstract

Background and objectives: Uropathogenic Escherichia coli (UPEC) is a leading cause of urinary tract infections, which are a significant public health concern worldwide. Antibiotic resistance among UPEC isolates is an increasing challenge, necessitating a better understanding of the resistance patterns and underlying genetic mechanisms. This study examined the prevalence of antibiotic resistance phenotypes and the detection of specific resistance genes among patients with UPEC infections in Sheikh Ragheb Harb University Hospital in south Lebanon.

Materials and methods: Antimicrobial resistance phenotype of 104 urine samples was tested to determine the resistance percentages for various antibiotics including ampicillin, gentamicin, ciprofloxacin, tetracycline, bactrim, meropenem, and imipenem using disk diffusion test. Additionally, molecular analysis like polymerase chain reaction (PCR) was performed to detect the presence of bla _SHV, qnrA, tetA, dfrA1, aac3, bla _OXA and bla _IMP resistance genes.

Results: The antimicrobial resistance testing revealed the following resistance percentages for various antibiotics: ampicillin (100%), gentamicin (15.38%), ciprofloxacin (34.61%), tetracycline (48.07%), bactrim (17.3%), meropenem (0.96%) and imipenem (0.96%). The analysis of resistance genes showed the presence of bla _SHV (7.96%), qnrA (0.96%), tetA (20.19%), and dfrA1 (0.96%) genes, while the aac3, bla _OXA, and bla _IMP genes were not detected.

Conclusion: The high rates of antibiotic resistance observed, particularly to ampicillin and tetracycline, highlight the need for more judicious antibiotic use and the development of alternative treatment strategies to combat UPEC infections. These results can inform antimicrobial stewardship programs and guide the selection of appropriate empiric therapy for urinary tract infections.

Keywords: Antibiotic resistance; Polymerase chain reaction; Resistance genes; Urinary tract infection; Uropathogenic Escherichia coli.

Fig. 1.

Percentages of antibiotic resistance phenotype among patients.

Fig. 2.

Percentages of antibiotic resistance genes among patients.

Fig. 3.

DNA bands observation of patients suffering from tetracycline resistance phenotype. An agarose gel (1.5%) was run at 80–120 volts for 30 minutes. Molecular weight ladder (Solis BioDyne) is indicated in lane L, while samples 1,2,3 and 4 show amplification products at approximately 577 bp. The gel was stained with Ethidium Bromide for visualization. L: ladder DNA (100bp to 1000bp), 1–6: tested patients, NC: negative control.