Genetyping of Carbapenem-resistant Organisms Isolated from Clinical Isolates Received from Tertiary Care Hospitals of Ahmedabad, Gujarat

Abstract

The world is seeing a continuous rise in the levels of antibiotic resistance1. Organisms develop new resistance mechanisms, emerge, and spread the resistance worldwide, making it challenging to treat common infectious diseases. In the current study, clinical isolates received between the years 2017 to 2020 were cultured and the isolated organisms were screened for antibiotic resistance; isolates with multiple drug resistance were further subjected to confirmatory screening through Combined Disc Test (CDT) and Modified Hodge Test (M.H.T.), and molecular characterization to be finally tested for gene expression analysis. Molecular characterization involved screening of genes blaVIM-2, blaKPC-3, blaNDM-1, and blaIMP-11 responsible for imparting carbapenem drug resistance2. From the laboratories of tertiary care hospitals, a total of 1452 clinical isolates were collected and identified. The organisms were subjected to antibiotic susceptibility screening and carbapenem resistance screening. The isolates found positive in the screenings were subjected to molecular characterization for genes, blaVIM-2, blaKPC-3, blaNDM-1, and blaIMP-11, responsible for imparting carbapenem drug resistance. Most of the isolates were resistant variably to aminoglycosides but were found to be resistant to fluoroquinolones and β-lactams group of antibiotics. Carbapenem activity was detected in twelve percent of total isolates and 27 percent among multidrug-resistant isolates. blaNDM-1 gene was found present in 77% isolates, and five organisms among the total number of organisms showed pan drug resistance.