Molecular typing of KPC variants and clonality assessment of carbapenem-resistant Klebsiella pneumoniae isolates obtained from blood cultures of hospitalized and ICU-admitted patients at the Hospital Universitario Mayor - Méderi in Bogotá D.C.

Abstract

Carbapenem resistance in Klebsiella pneumoniae is mainly associated with the production of KPC. KPC-producing K. pneumoniae (KPC-Kp) represents an urgent threat to global public health given the limited antibiotic therapies available to treat nosocomial infections caused by these strains. Given that Colombia is a KPC endemic country, efforts must be made to monitor and understand the molecular mechanisms involved in blaKPC dissemination. In this study, 73 carbapenem-resistant K. pneumoniae (CRKP) isolates were collected and identified from blood cultures of 28 patients at Hospital Universitario Mayor - Méderi in Bogotá between 2022 and 2023. The blaKPC gene variants were amplified by conventional PCR and identified by capillary sequencing. Clonal relationships among CRKP isolates were determined by Repetitive Extragenic Palindromic PCR (REP-PCR). Molecular typing showed 89.0% of CRKP isolates carrying the blaKPC gene. The blaKPC-3 variant had the highest incidence (78.1%), followed by blaKPC-2 (11.0%). In total, 22 REP-PCR clones were identified, of which 13 were clusters, 9 were singletons and 4 were found circulating between ICU and hospitalization. These findings provide insightful information for therapeutic management guidelines and contribute to local and national KPC surveillance.

La resistencia a carbapenémicos en Klebsiella pneumoniae se asocia principalmente a la producción de KPC. K. pneumoniae productora de KPC (KPC-Kp) representa una amenaza urgente para la salud pública mundial dadas las limitadas terapias antibióticas disponibles para tratar las infecciones nosocomiales causadas por estas cepas. Dado que Colombia es un país endémico para KPC, se deben hacer esfuerzos para monitorear y entender los mecanismos moleculares involucrados en la diseminación de blaKPC. En este estudio, se recolectaron e identificaron 73 aislamientos de K. pneumoniae resistente a carbapenémicos (CRKP) a partir de hemocultivos de 28 pacientes del Hospital Universitario Mayor - Méderi de Bogotá entre 2022 y 2023. Las variantes del gen blaKPC se amplificaron por PCR convencional y se identificaron por secuenciación capilar. Las relaciones clonales entre los aislamientos se determinaron por amplificación de secuencias palindrómicas extragénicas repetitivas (REP-PCR). La tipificación molecular mostró que el 89,0% de los aislamientos CRKP eran portadores del gen blaKPC. La variante blaKPC-3 tuvo la mayor incidencia (78,1%), seguida de blaKPC-2 (11,0%). En total, se identificaron 22 clones REP-PCR, de los cuales 13 eran grupos, 9 eran únicos y 4 se encontraron circulando entre los ambientes de hospitalización y UCI. Estos hallazgos proporcionan información útil para las guías de manejo terapéutico del hospital y contribuyen a la vigilancia local y nacional de KPC.