Serogroup Distribution, Diversity of Exotoxin Gene Profiles, and Phylogenetic Grouping of Ctx-M-1- Producing Uropathogenic Escherichia Coli Publisher Pubmed



Shokouhi Mostafavi SK¹ ; Najarpeerayeh S¹ ; Mohabbati Mobarez A¹ ; Kardoust Parizi M² Show Affiliations
Source: Comparative Immunology# Microbiology and Infectious Diseases Published:2019

Abstract

The emergence of CTX-M-1 producing Uropathogenic Escherichia coli (UPEC) has become a serious challenge. In addition to antimicrobial resistance, a number of virulence factors have been shown. Therefore, this study was designed to determine the prevalence of O- serogroups, phylogenetic groups, exotoxin genes, and antimicrobial resistance properties of CTX-M-1- producing UPEC. A total of 248 UPEC isolates were collected. The antibiotic resistance was performed, and PCR was used to detect the blaCTX-M1, exotoxins, serogroups and phylogroups of UPEC. Of 248 isolates, 95 (38.3%) harbored blaCTX-M-1. Of them, serogroups O1 and O25 were predominant, accounting for 20% and 13.7%, respectively. The hlyA was the dominant exotoxin gene (32.6%), followed by sat (28.4%), vat (22.1%), cnf (13.7%), picU (8.4%), and cdt (2.1%). The hlyA gene was significantly associated with pyelonephritis (P = 0.003). Moreover, almost half of the isolates (45.4%) belonged to phylogenetic group B2. Most of exotoxin genes were present in significantly higher proportions in group B2 isolates except cdt gene (P < 0.05). All of the isolates were susceptible to imipenem, nitrofurantoin, and fosfomycin. The CTX-M-1-producing UPEC strains causing nosocomial infections are more likely to harbor certain exotoxin genes, raising the possibility that this increase in virulence genes may result in an increased risk of complicated UTI. © 2019 Elsevier Ltd