Fluoroquinolone Resistance in Relation to Phylogenetic Background and Iron Uptake Associated Virulence Profile among Urinary Escherichia coli Isolates from HIV and Non-HIV Patients

Introduction: Urinary tract infection is a major cause of morbidity among HIV patients and is more
often underestimated in developing countries. Urinary Escherichia coli isolated from HIV and non-HIV
patients in South India were analyzed to determine the virulence profile and phylogenetic distribution
and their correlation with fluoroquinolone (FQ) resistance.
Methods: This study aimed to assess the difference in the incidence of iron uptake associated
virulence genes among urinary E. coli isolated from HIV (n= 76) and non-HIV antenatal patients
(n=42). We compared the incidence of virulence associated genes (VAGs) among the E. coli isolates
in relation to FQ resistance, phylogeny and host immunocompromise.
Results: fyuA was higher among the isolates from HIV than from non-HIV patients (P=0.00024).
E. coli isolates from HIV, non-HIV patients primarily belonged to the phylogroups D and B2
respectively. Q and FQ resistance were higher among isolates from HIV patients compared to non-
HIV patients (P=0.000414, P<0.0001 respectively). PhylogroupB2 strains were predominant among
the FQ susceptible than FQ-resistant strains (P=0.000652). fyuA and iutA was higher among the Qresistant
isolates than their susceptible counterparts (P<0.0001; P=0.000132). FQ resistant isolates
harboured fyuA, iutA than the susceptible isolates (P=0.0063; P=0.000478). Hly+ phenotype was
significantly associated with FQ-susceptible isolates (P=0.003253).
Discussion: Our results establish the relative predominance of non-hemolytic, fyuA+, Q, FQ resistant
E. coli isolates primarily of phylogroup-D among the HIV patients and there by suggests that non-B2
strains with lower virulence but with increased antibiotic resistance establish infection in HIV patients.