Biology subjects

Joshi, D. R.

Publications and source records attributed to Joshi, D. R..

2 recordsLinked to original sources

bioRxiv2024

Prevalence of Class 1 integron in disease-causing carbapenem-resistant Escherichia coli in a tertiary hospital in Kathmandu, Nepal

BackgroundHigh prevalence of carbapenem resistance genes have been abundantly reported within clinical E. coli in Nepal but their co-prevalence with class-1 integron is poorly documented. These Class I Integrons play pivotal role in evolution and spread of antimicrobial resistance (AMR). Therefore, it is necessary to highlight their epidemiological significance, so this study determined the prevalence of Class 1 integrons within Carbapenem resistance Escherichia coli (CREc) population. MethodsFifty-two clinical E. coli with confirmed resistance to Meropenem were collected between January 2020-April 2022 in Kathmandu Model Hospital, and undergone antimicrobial susceptibility testing for 11 antimicrobial classes. Carbapenemase production was confirmed by eCIM and mCIM methods. Presence of Class I integron and carbapenemase genes, blaNDM-1, blaKPC, blaIMP, blaVIM, blaOXA-23, blaOXA-48, was confirmed by PCR method. ResultsThe result revealed 92.3% (n=48/52) of the isolates harbored intI1 gene. Among integron-positive population, 97.9% (n=47/48) were carbapenemase producers which were further identified as metallo {beta}-lactamase (MBL) producers (82.9%, n=39/47) and serine {beta}-lactamase (SBL) producer (17%, n=8/47). Carbapenemase gene blaNDM-1 (79.2%, n=38/48) was highly prevalent within integron-positive isolates, followed by blaOXA-23 (62.5%, n=30/48) and blaOXA-48 (54.2%, n=26/48). All integron-positive CREc isolates were resistant to minimum 16 antibiotics tested, but were susceptible to Colistin, Polymixin B, and Tigecycline. ConclusionIn conclusion, Class 1 integrons were highly prevalent within clinical CREc in Nepal, and their co-prevalence with other CRE gene is concerning due to possibility of wider spread. Therefore, an in-depth genomic analysis of Class 1 integrons is needed to understand the integron mediated AMR in high risk clones like CREc and inform intervention measures to stop spread of such pathogens.

microbiology↗

bioRxiv2023

Emergence of ISAba1-linked oxacillinase genes among carbapenem resistant Acinetobacter baumannii isolates in a tertiary cardiac center, Nepal

Insertion sequence contributes to the emergence of carbapenem resistance by dissemination of carbapenemase genes and providing promoter for their overexpression. This study aims to ascertain the occurrence of ISAba1-linked OXA carbapenemase genes and its relevance to carbapenem resistance level in Acinetobacter baumannii. This hospital based descriptive study was conducted at Shahid Gangalal National Heart Center, Kathmandu, Nepal. An overall of 1,291 clinical specimens received for routine culture and antibiotic susceptibility testing throughout the study period were included in this study. Identification of Acinetobacter baumannii was validated through detection of intrinsic blaOXA-51-like gene by polymerase chain reaction (PCR). Antibiotic susceptibility was tested by Kirby-Bauer disc diffusion approach and minimum inhibitory concentration (MIC) of meropenem was assessed through agar dilution method. Uniplex PCR assays were performed to detect genes encoding oxacillinases and ISAba1. Upstream association of insertion element, ISAba1 to oxacillinase genes was assessed through PCR mapping strategy using ISAba1F and OXA-51R/OXA-23R primers. Out of the 340 bacteria isolated, only 40 (11.8%) were Acinetobacter baumannii. All isolates were resistant against meropenem with MIC value ranging from 16-256 g/ml. blaOXA-23-like genes was present in every isolate but blaOXA-58 in just two isolates (5%). All isolates had ISAba1 either above blaOXA-23-like or blaOXA-51-like gene. Higher MIC90 value of meropenem (243.20 g/ml) was found in A. baumannii cluster with ISAba1-linked upstream to both blaOXA-23-like and blaOXA-51-like genes, thus depicting their eminent role to enhanced carbapenem resistance. Acinetobacter baumannii isolates with ISAba1-linked oxacillinase genes are rapidly emerging in clinical settings of Nepal. Thus, medical communities need to be prepared and enable targeted approaches for managing burgeoning problem of carbapenem resistance.

microbiology↗