characteristics of colistin-resistant and colistin-sensitive isolates of carbapenem-resistant klebsiella pneumoniae among hospitalized patients in tehran, iran

Background: resistance to antibiotics is a prominent issue in treating infections caused by klebsiella pneumoniae. objectives: the present study aimed to investigate the prevalence of carbapenem and colistin-resistant (colr) k. pneumoniae and their molecular characteristics in a hospitalized patient in tehran, iran. methods: this cross-sectional study was performed on k. pneumoniae isolated from different wards of a hospital during 2020 - 2021. following the biochemical identification of the isolates, their antibiotic resistance was evaluated. genes of blactx-m, blandm, blaoxa-48, blakpc, and mcr-1 were identified in isolates by pcr. the data were analyzed using spss software. results: a total of 380 isolates of k. pneumoniae were collected, of which 275 (72.3%) were extended-spectrum beta-lactamase (esbl) producers, among which 49.4% (n = 136/275) were carbapenemase producers, and 62.5% (n = 85/136) were colr. blaoxa-48 and blandm were the dominant genes. there was a significant correlation between the high prevalence of the blandm gene and colr isolates (p = 0.038). conclusions: our findings revealed the high prevalence of carbapenem-resistant isolates, likely due to the excessive clinical use of carbapenems in hospitals. the high prevalence of the blandm gene in colr carbapenem-resistant klebsiella pneumoniae (crkp) isolates could indicate the high incidence of a specific clone that contributes to the simultaneous acquisition of resistance genes among patients.