Analysis of the presence of the bla_CTX-M genes in Escherichia coli isolated from downstream of the Bekasi River

Environmental Engineering Study Program, Department of Civil Engineering, University of Indonesia, Depok, West Java, 16424, Indonesia

^* Corresponding author: lathifah.hana@ui.ac.id

Abstract

Antimicrobial resistance (AMR) is a global public health threat caused by antibiotic resistance genes (ARGs), such as bla_CTX-M. The bla_CTX-M is one of the most common ARGs that confers cephalosporin resistance. This study aimed to investigate the concentrations of cefotaxime-resistant Escherichia coli (E. coli) and the presence of the bla_CTX-M in E. coli isolated from downstream of the Bekasi River. The results of this study provided some information on AMR in reservoir environmental bacteria. This study used polymerase chain reaction (PCR) to amplify DNA and gel electrophoresis to visualize the target genes. The results are downstream of the Bekasi River had an average concentration of non-selective E. coli (2,3 ± 0,4) × 10⁴ CFU/100mL and the average concentration of cefotaxime-resistant E. coli (2,1 ± 0,6) × 10³ CFU/100 mL. The ratio of antibiotic-resistant E. coli to non-selective E. coli was 9.4%. The bla_CTX-M genes were detected in 80% of E. coli isolates, with blaCTX-M group 1 genes predominating, which includes the bla_{CTX-M -1}, bla_CTX-M-3, and bla_CTX-M-15 genes.