Occurrence of extended-spectrum beta-lactamase producing escherichia coli in groundwater

¹ Environmental Engineering Study Program, Department of Civil Engineering, Faculty of Engineering, Universitas Indonesia, Depok, Jawa Barat, 16424, Indonesia
² Research Center for Advanced Science and Technology, The University of Tokyo, Japan

^* Corresponding author: rahmatika.iftita@gmail.com

Abstract

Groundwater is a vital source of clean water globally. The presence of E.coli, specifically ESBL-producing E.coli (ESBL-Ec), in groundwater can pose a significant risk to human health. This study aimed to analyze the concentrations of E.coli and ESBL-Ec in five groundwater samples (A1-A5) near the Cipayung landfill, as well as one groundwater (A6) from a residential area. Morevorer, one septic tank sample located near A6 was also collected (ST). Characterization of the the bla_CTX-M gene associated with cefotaxime resistance were conducted. Phenotypic analysis involved the Double Disk Sinergy Test to confirm ESBL enzyme activity against antibiotics, while genotypic analysis utilized the Multiplex PCR to characterize the bla_CTX-M gene. Results indicated that the E. coli concentrations in groundwater ranged from (4.0 ± 2.0) × 10^-1 CFU/100 mL to (4.0 ± 0.3) × 10³ CFU/100 mL. ESBL-Ec was consistently detected at A1, A2, A4, and ST with average concentrations of (6.5 ± 3.0) × 10⁰ CFU/100 mL, (1.3 ± 0.5) × 10⁰ CFU/100 mL, (1.1 ± 0.1) × 10¹ CFU/100 mL, and (7.2 ± 1.1) × 10³ CFU/100 mL, respectively. Multiplex PCR revealed the presence of bla_CTX-M group 1 and group 2 genes at samples A1, A2, A4, and ST. This study highlighted the need for preventive measures to minimize ESBL-Ec spread in groundwater.