Molecular Epidemiology of Multidrug-resistant Escherichia coli from Urinary Tract Infections

Objectives: The purpose of this study was to investigate the phylogenetic groups, antibiotic resistance, antibiotic resistance genes (ARGs), integrons, extraintestinal virulence genes and genetic diversity of Escherichia coli isolates from human urinary tract infection. Methods: A total of 100 E. coli isolates were collected from patients with urinary tract infections in Kerala, South India. Antibiotic susceptibility testing of all E. coli isolates against different antibiotics was determined by the disc diffusion method. Phylogenetic groups, extraintestinal virulence genes, ARGs, and integrons were detected by PCR. Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) was used to check the genetic relatedness among E. coli isolates. Results: E. coli isolates have mainly belonged to phylogenetic group B2. Resistance to ampicillin was most frequent among the E. coli isolates followed by resistance to cefoxitin, cefpodoxime, nalidixic acid, trimethoprim, and co-trimoxazole. Among E. coli isolates, 96% were multidrug-resistant (MDR), and 86% and 32% harbored ARGs and integrase 1 (int1) respectively. Seventy-nine percent of the isolates were extraintestinal pathogenic E. coli (ExPEC), and 86% of them (n = 68) harbored ARGs. One extensively drug-resistant (XDR) ExPEC was obtained in this study. The present study revealed a significant association between the presence of virulence genes and antibiotic resistance. A high degree of genetic diversity was observed among the ARGs-harboring E. coli isolates. Conclusion: Understanding the association between extraintestinal virulence genes and antibiotic resistance genes would result in the proper treatment of urinary tract infections. J Microbiol Infect Dis 2021; 11(2):66-73.