MOLECULAR EPIDEMIOLOGY OF KLEBSIELLA PNEUMONIAE BLOOD ISOLATES RESISTANT TO 3RD GENERATION CEPHALOSPORINS AND/OR CARBAPENEMS COLLECTED FROM PATIENTS IN A BULGARIAN UNIVERSITY HOSPITAL

The purpose of this study is to evaluate the epidemiological relationship between carbapenem-resistant (CR) and/or 3rd generation cephalosporin resistant Klebsiella pneumoniae blood isolates collected from patients in the University Hospital in Varna city during the period January 2014 - December 2017 and to characterize the ESBLs and carbapenemase production in these isolates. A total of 41 consecutive 3rd generation cephalosporin and/or carbapenem resistant isolates were investigated. One K. pneumoniae isolated from the hands of a healthcare worker, was also included in this study. Antimicrobial susceptibility was determined by Phoenix (BD) and the results were interpreted according to EUCAST guidelines 2017. The identification of ESBLs and carbapenemase encoding genes was performed by PCR and sequencing. The isolates were genotyped by ERIC PCR and ILST. Bla genes, encoding ESBLs were found in 40 isolates (95.2%). The most widespread ESBL was CTX-M-15, found in 90.5% (n = 38). CTX-3 was found in two isolates only. Twenty-one isolates were resistant to carbapenems. The predominant carbapenemase was KPC-2, detected in 19 of all CR isolates. Two isolates were NDM-1 producers. Ten different ERIC types were detected - MLST 15, 76, 11, 340, 1350, 902, 70, 359, 37 and 35. ST15 (ERIC type A) was predominant, found in 23 isolates during the whole study period. The isolate from the hands of a healthcare worker also demonstrated ST15. ST76 (ERIC B) and ST11 (ERIC C) were presented by five and four isolates, respectively. ST340 and ST1350 types were found in two isolates each. ST 902, 70, 359, 37 and 35 were identified in single isolates. KPC-2 production was associated with ST15, ST76 and ST1350 types. NDM-1 carbapenemase was found in two ST11 isolates. During the four-year study period wide intrahospital dissemination of KPC-2 and/or CTX-M-15 producing Klebsiella pneumoniae was identified. ST15 persisted during the whole period, demonstrating high cross transmission, epidemic and invasive potential.

Automated summary

This study evaluated the epidemiological relationship between carbapenem-resistant (CR) and/or 3rd generation cephalosporin resistant Klebsiella pneumoniae blood isolates collected from patients in the University Hospital in Varna city during the period January 2014 - December 2017. The study also aimed to characterize the ESBLs and carbapenemase production in these isolates. The findings revealed a wide intrahospital dissemination of KPC-2 and/or CTX-M-15 producing Klebsiella pneumoniae, with ST15 persisting throughout the study period, demonstrating high cross transmission, epidemic and invasive potential.