Genetic Characterization Among Carbapenem-resistant Escherichia coli Strains Using Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR) Fingerprinting in South Africa

Abstract Background Carbapenems belong to beta-lactam class of antibiotics usually considered as the last line of defense because they can be effective against severe infections caused by prevalent multidrug-resistant (MDR) pathogens. However, carbapenems can be deactivated by bacteria that produce carbapenemase (beta-lactamase). This study was conducted to screen for carbapenem-resistance genes (CRGs) harbored by pathogenic strains of Escherichia coli recovered from different environmental samples. We also assessed the genetic relatedness among selected E. coli pathotypes using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR).Method: Molecular identification and characterization of the presumptive isolates were performed using PCR and isolates that exhibited antimicrobial resistance (AMR) phenotypically were further screened for some relevant CRGs (blaNDM−1, blaKPC and blaOXA−48−like). Furthermore, ERIC-PCR was used to determine the similarity and diversity of 31 E. coli strains which were randomly selected from the different sources analyzed in this study.Result Our findings revealed a total of 238 presumptive E. coli isolates, out of which 192 were confirmed positive for uidA gene. Further screening revealed 77 (40%) isolates belong to six key E. coli pathotypes and 70 of them exhibited phenotypic AMR. Additionally, twenty-nine (41%) of the 70 MDR pathogenic E. coli strains harbored CRGs; with 24 strains harboring blaNDM−1, 8 harboring blaKPC and 2 harboring blaOXA−48−like genes.Conclusion Findings also suggest that the selected E. coli pathotypes belonged to different genomic clusters, while the cluster analysis showed a possible genetic diversity among aquatic and farm isolates. Proper treatment of final effluents before discharge as well as the development of more effective strategies to control and manage the use of antimicrobial agents were strongly recommended.