Colistin- and Carbapenem-Resistant Klebsiella pneumoniae Isolated from Blood Cultures Among Neonates in a Regional Hospital in Turkey

Abstract

1. pneumoniae is a cause for concern due to its ability to produce carbapenemases and carry multiple resistance genes, characteristics that define it as a 'difficult-to-treat' pathogen. This study aimed to perform a microbiological analysis of colistin- and carbapenem-resistant Klebsiella pneumoniae strains isolated from blood cultures of neonates in our hospital. Between January 2022 and December 2022, patients with bloodstream infections in the neonatal intensive care units (NICUs) at Van Training and Research Hospital were monitored. All isolates were identified using the Vitek II automated microbiological identification system and conventional biochemical tests. Antibiotic susceptibility and minimum inhibitory concentrations (MICs) were determined using the broth microdilution method. Polymerase chain reaction (PCR) was used to identify the resistance mechanisms of K. pneumoniae isolates. Pulsed-Field Gel Electrophoresis (PFGE) and multilocus sequence typing (MLST) were employed to determine clonal relatedness. Of the 27 neonates diagnosed with bloodstream infections, 10 were preterm and 17 were full-term infants. Confirmation using the Vitek II system identified all 27 samples as positive for K. pneumoniae isolates. Among the environmental samples, the presence of multidrug-resistant K. pneumoniae was detected in the filtered incubator water sample. Antibiotic susceptibility testing results revealed that all isolates, including the environmental one, with the exception of a single isolate, were resistant to first-generation cephalosporins, aminoglycosides, carbapenems, and colistin. K. pneumoniae strains were found to carry various resistance genes. The prioritized detection of such high-risk clones of multidrug-resistant strains, surveillance practices, and appropriate infection control programs are crucial for preventing infections and limiting their further spread into the community.