Resumen Introducción: Existe un incremento de las infecciones por Klebsiella pneumoniae resistente a carbapenémicos (KPRC) en la población pediátrica y los datos epidemiológicos son limitados. Objetivos: Conocer la frecuencia de KPRC en pacientes pediátricos, determinar la actividad in vitro de colistina y detectar el gen mcr-1 en dichos aislados. Materiales y Métodos: Se estudiaron 220 aislados de K. pneumoniae en un hospital pediátrico durante los años 2018 y 2019. La susceptibilidad antimicrobiana se determinó por microdilución en caldo según CLSI y EUCAST. Los genes blaKPC, blaNDM, blaIMP, blaVIM, blaOXA-48 y mcr-1 se analizaron mediante reacción de polimerasa en cadena (RPC). Resultados: El 9,5% (n: 21) de los aislados fueron caracterizados como KPRC, donde se observó una resistencia a colistina de 47,6% (10/21) con valores de CIM50 de 2 μg/mL y CIM90 de > 4 μg/mL. En todos los aislados de KPRC se caracterizó el gen blaKPC y no se detectó el gen mcr-1. El perfil de resistencia observado en otros antimicrobianos fue el siguiente: gentamicina 100% (n: 21), ciprofloxacina 100% (n: 21), cotrimoxazol 100% (n: 21) y amikacina 19% (n: 4). Se observó 100% de sensibilidad a tigeciclina y ceftazidima/avibactam. Conclusión: Este estudio demuestra un valor significativo de la resistencia a colistina en comparación a ceftazidima/avibactam y tigeciclina.

Abstract Background: There is an increase of carbapenem-resistant Klebsiella pneumoniae (CRKP) infections in the pediatric population and epidemiological data are limited. Aim: To calculate the frequency of CRKP in pediatric patients, to determine the in vitro activity of colistin and to detect the presence of mcr-1 gene in said isolates. Methods: 220 isolates of K. pneumoniae were studied in a pediatric hospital between January 2018 and December 2019. Antimicrobial susceptibility was determined by microdilution in broth according to guidelines of CLSI and EUCAST. The genes blaKPC, blaNDM, blaIMP, blaVIM, blaOXA-48 and mcr-1 were detected by polymerase chain reaction (PCR). Results: 9.5% (n: 21) of the isolates were characterized as CRKP, where was observed a resistance to colistin of 47.6% (10/21) with values of MIC50 of 2 μg/mL and MIC90 of ≥ 4 μg/mL. In 100% of CRKP strains the blaKPC gene was detected and the mcr-1 gene was not found. The resistance profile to other antimicrobials was as follow: gentamicin 100% (n: 21), trimethoprim/sulfamethoxazole 100% (n: 21), ciprofloxacin 100% (n: 21), amikacin 19% (n: 4). All of the isolates were sensitive to ceftazidime/avibactam and tigecycline. Conclusion: This study demonstrates a significant value of resistance to colistin in pediatric patients compared to other last line antimicrobial such as ceftazidime/avibactam and tigecycline.

O objetivo deste trabalho foi detectar a presença de Salmonella spp. em ambientes aquáticos para uso recreativo no Nordeste da Argentina e relacioná-la com parâmetros ambientais e das águas. Foram estudados sessenta e oito amostras de água de ambientes aquáticos de lazer nas províncias de Chaco e Corrientes, Argentina. Salmonella spp. foi detectada em seis amostras (8,8%). Salmonella spp. isolados pertenciam às espécies e sorovares S. enterica ser. Give, S. enterica subespécie IV, S. enterica ser. Bredeney, S. enterica ser. Rubislaw e S. enterica ser. Enteritidis (dois isolados). Nenhum dos isolados testados foram resistentes aos antimicrobianos. Não existiam diferenças significativas entre os isolamentos de Salmonella spp. e os locais de amostragem e o restante das variáveis. A presença de Salmonella spp. em nossos ambientes aquáticos para uso recreativo reafirma a necessidade de vigilância, a fim de minimizar os riscos de infecção das pessoas suscetíveis expostas.

The aim of this work was to detect the presence of Salmonella spp. in recreational aquatic environments in the Northeast of Argentina and to relate it with water and environmental parameters. Sixty eight samples of water from recreational aquatic environments in the provinces of Chaco and Corrientes, Argentina, were studied. Salmonellae were detected in 6 samples (8.8%). Salmonella spp. isolates belonged to the following species and serovars: S. enterica serovar Give, S. enterica subespecie IV, S. enterica ser. Bredeney, S. enterica ser. Rubislaw, and S. enterica ser. Enteritidis (two isolates). None of the isolates were resistant to tested antimicrobials. There were no significant differences among sampling sites as a reservoir of bacteria Salmonella spp. and the other variables. The presence of Salmonella spp. in our recreational aquatic environments reaffirms the need for monitoring in order to minimize the risks of infection to exposed persons.