Antibiotic resistance determinants among carbapenemase producing bacteria isolated from wastewaters of Kathmandu, Nepal

Sudeep K C; Santosh Khanal; Tista Prasai Joshi; Deegendra Khadka; Reshma Tuladhar; Dev Raj Joshi

doi:10.1016/j.envpol.2023.123155

Antibiotic resistance determinants among carbapenemase producing bacteria isolated from wastewaters of Kathmandu, Nepal

Environ Pollut. 2024 Feb 15:343:123155. doi: 10.1016/j.envpol.2023.123155. Epub 2023 Dec 17.

Authors

Sudeep K C¹, Santosh Khanal², Tista Prasai Joshi³, Deegendra Khadka⁴, Reshma Tuladhar⁵, Dev Raj Joshi⁶

Affiliations

¹ Central Department of Microbiology, Tribhuvan University, Kirtipur, Nepal; Environment Research Laboratory, Faculty of Science, Nepal Academy of Science and Technology (NAST), Lalitpur, Nepal.
² Central Department of Microbiology, Tribhuvan University, Kirtipur, Nepal; Environment Research Laboratory, Faculty of Science, Nepal Academy of Science and Technology (NAST), Lalitpur, Nepal; Department of Microbiology, Tri-Chandra Multiple Campus, Tribhuvan University, Kathmandu, Nepal.
³ Environment Research Laboratory, Faculty of Science, Nepal Academy of Science and Technology (NAST), Lalitpur, Nepal.
⁴ Molecular Biotechnology, Faculty of Science, Nepal Academy of Science and Technology (NAST), Lalitpur, Nepal.
⁵ Central Department of Microbiology, Tribhuvan University, Kirtipur, Nepal.
⁶ Central Department of Microbiology, Tribhuvan University, Kirtipur, Nepal. Electronic address: dev.joshi@cdmi.tu.edu.np.

PMID: 38114055
DOI: 10.1016/j.envpol.2023.123155

Abstract

The emergence of carbapenem resistant bacteria (CRB) possesses a remarkable threat to the health of humans. CRB and carbapenem resistance genes (CRGs) have frequently been reported in clinical isolates from hospitals, however, their occurrence and distribution in wastewaters from various sources and river water have not been emphasized in Nepal. So, this study aimed to detect carbapenem resistant bacterial isolates and their resistance determinants in river water and different types of wastewaters. River water and both untreated and treated wastewater samples from hospitals, pharmaceutical industries, and municipal sewage were collected in summer and winter seasons. From 68 grab wastewater samples, CRB were detected only in 16 samples, which included eight hospital wastewater, and four each from untreated municipal sewage and river water. A total of 25 CRB isolates were detected with dominance of E. coli (44.0%) and K. pneumoniae (24.0%). The majority of the isolates harbored bla_NDM-1 (76.0%), followed by bla_OXA (36.0%) and bla_KPC (20.0%) genes. Hospital wastewater majorly contributed to the presence of bla_NDM-1, bla_KPC, and bla_OXA along with intI1 genes compared to river water and untreated municipal sewage, especially during the winter season. However, CRB were not detected in treated effluents of hospitals and municipal sewage, and both influents and effluents from pharmaceutical industries. The combined presence of each bla_NDM-1 & bla_OXA and bla_KPC & bla_OXA occurred in 16.0% of the bacterial isolates. The increased minimum inhibitory concentration (MIC) of meropenem was significantly associated with the presence of CRGs. The results of this study highlight the significance of carbapenem resistance in bacteria isolated from wastewater and river water, and underscore the necessity for efficient monitoring and control strategies to prevent the dispersion of carbapenem resistance in the environment and its potential consequences on human health.

Keywords: Antimicrobial resistance; Carbapenem resistance genes; Integrons; River water; Wastewater.

MeSH terms

Anti-Bacterial Agents* / pharmacology
Bacterial Proteins / genetics
Carbapenems / pharmacology
Drug Resistance, Microbial
Escherichia coli
Humans
Klebsiella pneumoniae / genetics
Microbial Sensitivity Tests
Nepal
Sewage
Wastewater*
Water
beta-Lactamases / genetics

Substances

carbapenemase
Anti-Bacterial Agents
Wastewater
Sewage
Bacterial Proteins
beta-Lactamases
Carbapenems
Water