Avaliação da diversidade clonal de Klebsiella pneumoniae produtoras de KPC provenientes de espécimes clínicos, através das técnicas de PFGE, MLST e MALDI-TOF

Abstract

Species of K. pneumoniae producing carbapenemases have been routinely isolated in hospital environments, especially causing severe infections, in which MDR and XDR isolates pose a serious public health problem. Worldwide, studies have associated epidemic clones with the spread of carbapenemases, highlighting CC11/258 as a significant disseminator of KPC carbapenemase. Therefore, molecular typing of circulating clones carrying the blaKPC gene is crucial for investigating hospital outbreaks as well as for epidemiological surveillance. The aim of this study was to perform a comprehensive evaluation of the clonal diversity of KPC-producing K. pneumoniae strains collected from different Brazilian states and sent for routine analysis at the Laboratório de Bacteriologia Aplicada à Saúde Única e Resistência antimicrobiana (LabSUR). The selected isolates for the study had their species confirmed by MALDI-TOF, and the presence of KPC carbapenemase was investigated by conventional PCR. Molecular typing techniques PFGE and MLST were employed to assess the clonality relationship of the received strains. Additionally, the capability of MALDI-TOF Mass Spectrometry tool to evaluate the clonal diversity of the selected strains for the study was explored. A crucial part of this study involved the direct comparison of results obtained by MALDI-TOF technique with the clonal groups obtained through the PFGE methodology.. For the study, were selected122 KPC-producing K. pneumoniae isolates and the analysis of clonality relationship through PFGE in these isolates revealed 44 clonal groups. By MLST, 16 different sequence types were identified, highlighting CC11 as the most frequent. Typing using MALDI-TOF generated 31 clusters, with cluster 19 standing out with the highest number of grouped isolates, largely composed of PF10 and PF9. When analyzing the clustering profiles obtained by MALDI-TOF and comparing them with the clonal groups obtained by PFGE methodology and the STs obtained by MLST, it was not possible to establish a consistent correlation, necessitating further research to continue investigating the feasibility of applying the MALDI-TOF technique for molecular typing in KPC-producing K. pneumoniae. This could prove to be highly useful in contexts related to outbreak evaluation and monitoring, thus enabling control measure