Prevalence of Integrons, bla_CTX-M and bla_TEM Resistance Markers among ESBL-Producing Uropathogenic Escherichia coli Isolates: First Report of Genomic bla_CTX-M from India

Abstract

Integrons have been observed to be frequently associated with uropathogenic bacteria. This study aimed at 1) determining the prevalence of class 1 integrons among eSbl-producing uropathogenic Escherichia coli, and 2) analyzing resistance genes associated with different phylogenetic groups of the integron-positive isolates with special reference to bla _CTX-M and blatem. Twenty-three ESBL-producing E. coli were studied. Enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) displayed 14 major patterns. Pulse field Gel electrophoresis-typing of 8 randomly selected integron-positive strains ruled out any correlation between genotype and antibiotype. Genomic DNA from 14 strains was PCR-positive for class 1 integronsbla _CTX-M-15 and bla _TEM-1-like genes. Integron-sequencing revealed “aadA5-dfrA17-dfrA7” as the most prevalent gene cassette. Our findings unveil the increasing role of the bla-_CTX-M genes in antibiotic resistance and emphasize on the significance of appropriate empirical treatment for Urinary tract infections. Moreover, this is the first study which reports bla _CTX-M located on genomic DNA of bacteria from india.

Keywords:

• Antibiotic resistance
• CTX M
• extended Spectrum beta lactamases
• Genomic DNA
• integrons
• Urinary tract infection