Characterization of urinary Escherichia coli isolates in HIV-seropositive women with asymptomatic bacteriuria in Western Ghana.

BACKGROUND

Asymptomatic bacteriuria (ASB), a precursor of urinary tract infection (UTI), is highly prevalent among people living with HIV (PLHIV). In this study, we characterized urinary Escherichia coli isolated from PLHIV with asymptomatic bacteriuria.

METHODS

Urine samples from women living with HIV (WLHIV) were cultured, and bacteria isolates were identified using MALDI TOF biotyper. Antimicrobial susceptibility test was performed on isolates and genes encoding virulence factors and integrases were screened using Multiplex PCR and gel imaging. Patients' predictor variables like WHO disease staging, Highly Active Antiretroviral Therapy (HAART) duration and viral load were extracted from patient folders using a structured questionnaire.

RESULTS

The mean age of our 400 participants was 43.5 ± 12 years, 78.5% had viral loads < 1000 copies/ml, 53.8% had been on HAART for 1-5 years and 62.5% were classified as having WHO stage III disease. 85 of 400 (21.2%) urine samples cultured positive, and the most prevalent organism was E. coli (69.4%, 59/85), all being multidrug-resistant. None of the patients' predictor variables reached statistical significance; WHO disease stage (OR = 0.953, 95%CI = 0.683-1.330, p = 0.777), age (OR = 0.1.207, 95%CI = 0.971-1.499, p = 0.090), HAART duration (OR = 1.233, 95%CI = 0.923-1.648, p = 0.156, and viral load (OR = 0.915, 95%CI = 0.774-1.082, p = 0.298). Lower resistance rates were recorded for meropenem and fosfomycin (1.7%), nitrofurantoin (6.8%, 4/59) and amikacin (8.5%, 5/59). The most common virulence genes identified were chuA (66.1%, 39/59), papC (57.6%, 34/59) and cnf1 (50.8%, 30/59). Integrons identified were intI 42% (25/59) and intII 20% (12/59).

CONCLUSION

ASB is common in our HIV- seropositive participants, indicating that WLHIV are at a higher risk of developing complications from UTIs. Though fosfomycin may be useful in managing UTIs in this population group, the high prevalence of multidrug-resistant, E. coli harbouring diverse virulence genes, warrants surveillance of ASB among this vulnerable group.