Investigation of the blaNDM-1 and armA Genes in Carbapenem-Resistant Klebsiella pneumoniae Isolated from the Clinical Samples in Kathmandu, Nepal.

Abstract

Klebsiella pneumoniae carbapenemase (KPC) and metallo-β-lactamase production are major causes of carbapenem resistance, whereas aminoglycoside resistance is caused by extrinsically acquired 16S-rRNA methyltransferase. K. pneumoniae coharboring resistance genes are serious health care issues that can cause multidrug resistance (MDR). This study aimed to describe the resistance genes (New Delhi metallo-beta-lactamase 1 [blaNDM-1] and armA) in the plasmids of K. pneumoniae from patients visiting the Paropakar Maternity and Women's Hospital, Kathmandu, Nepal. All together, 8,017 clinical specimens were processed following standard microbiological procedures to identify K. pneumoniae. Antibiotic susceptibility testing and detection of phenotypic carbapenemase production in K. pneumoniae isolates were performed using the modified Kirby-Bauer disc diffusion method. The resistance genes were detected by conventional polymerase chain reaction. Of 8,017 clinical specimens, 6.8% (n = 545) had bacterial growth, and 70 were K. pneumoniae. Colistin (100%, n = 70) and imipenem (80%, n = 56) were the most effective antibiotics. Thirty percent (n = 21) of the isolates were MDR, whereas 66.7% (n = 14) were carbapenemase producers, among which 38.1% (n = 8) had a minimum inhibitory concentration of 64 µg/mL to imipenem. Among carbapenemase producers, 23.8% (n = 5) were KPC and 66.7% (n = 14) were metallo-β-lactamase producers. Out of 21 MDR K. pneumoniae, 19.5% (n = 4) harbored the blaNDM-1 and armA genes, and 14.3% (n = 2) had both genes. Detection of the coexistence of the resistance genes from K. pneumoniae reveals that there might be increased antibiotic resistance leading to multidrug resistance and an increased resistance to imipenem. In conclusion, advancing antimicrobial-resistance surveillance in maternity wards and minimizing the use of last-line antibiotics are crucial for safeguarding maternal and neonatal health.