Molecular Characterization of Carbapenemase Co-Production in Klebsiella Pneumoniae

Carbapenem-resistant Klebsiella pneumoniae represents a serious public health threat due to its high prevalence and therapeutic difficulty. This resistance is often associated with the production of carbapenemases such as KPC, NDM, and OXA-48. The dissemination of these isolates in hospital environments requires continuous surveillance and strict infection control measures. In this context, this study aimed to investigate the prevalence and the genes encoding carbapenemases in carbapenem-resistant clinical isolates of K. pneumoniae from hospitalized patients, as well as to verify carbapenemase co-production in these isolates. This is a cross-sectional study conducted between 2020 and 2023 at a public hospital located in the Zona da Mata region of Minas Gerais, Brazil. Carbapenem-resistant K. pneumoniae strains obtained from clinical samples were analyzed. Initial species identification was performed by phenotypic methods and subsequently confirmed by mass spectrometry. Screening for carbapenem resistance was conducted by phenotypic tests, and detection of the resistance genes blaKPC , blaNDM , blaOXA-48 , blaIMP , and blaVIM was carried out by real-time polymerase chain reaction (qPCR). The study was approved by the Human Research Ethics Committee. A total of 67 carbapenem-resistant clinical isolates of K. pneumoniae were included, 30 from the years 2020 to 2022 and 37 from 2023. Molecular analysis revealed that 56.71% (n = 38) of isolates had only the blaKPC gene, while 10.44% (n = 7) expressed only the blaNDM gene. Co-production of blaKPC and blaNDM was identified in 31.35% (n = 21) of samples, and co-production of blaKPC and blaOXA-48 was detected in 1.5% (n = 1). It was observed that all co-production cases occurred in 2023, totaling 22 of the 37 isolates from that period, corresponding to 59.45% of the strains analyzed that year. The detection of K. pneumoniae with co-production of carbapenemase genes demonstrates the complexity of this species’ resistance profile and its clinical relevance in the dissemination of carbapenem resistance. These findings reinforce the need for more effective control strategies, the maintenance of microbiological surveillance programs, and the continuous development of studies to support targeted clinical interventions.