Prophage and Plasmid-Mediated Beta-Lactamases in Multidrug-Resistant Extraintestinal Escherichia coli

Abstract Objectives  Antibiotic resistance can arise as a mutation to adapt to stress or be mediated by horizontal gene transfer. This study aimed at identifying the resistance determinants present in the mobile genetic elements of prophages and plasmids within multidrug-resistant (MDR) extraintestinal Escherichia coli . Materials and Methods  Thirty-five anonymized MDR E. coli isolates of nonintestinal infections were confirmed for their antimicrobial resistance to six categories of antimicrobials by the disk diffusion test. Genes coding for beta-lactamases and carbapenemases in bacterial genome, plasmid, and prophage fractions were separately determined by polymerase chain reaction. Transducing ability of prophages carrying resistance genes was determined. Results  Twenty-six isolates were positive for the gene bla CTX-M , nine for bla TEM , one each for bla KPC and bla VIM , thirteen for bla NDM, and seven for bla OXA . A majority of these isolates carried these determinants in plasmids and prophage fractions. Twenty-one percent of the prophage fractions (4 of 19) were able to successfully transfer resistance to sensitive isolates. Conclusions  This study indicates bla CTX-M , bla TEM, and bla NDM genes that are reported most frequently in MDR isolates are more frequent in the plasmid and prophage fractions thus supporting for increased mobility.