High frequency of colonization by extended-spectrum beta-lactamase-producing Gram-negative bacilli in hemodialysis patients and their household contacts: dissemination between the community and the hospital AbstractObjectives: Increase in colonization by beta-lactam-resistant Gram-negative bacilli (BR-GNB) represent a risk for infections and bacterial resistance spread, not only in hospitals but community. Hemodialysis patients and their household contacts transit constantly between the two environments. This study aims to determine the clinical and epidemiological characteristics of BR-GNB colonization in hemodialysis patients and their household contacts, as well as the genetic relationship between their isolates. Methods:A cross-sectional study was conducted on hemodialysis patients from hospital-associated dialysis center in Medellín-Colombia, and their household contacts. Clinical and epidemiological information was collected. Colonization was assessed from stool or rectal swab samples. Bacterial identification and susceptibility were determined using chromogenic media and Vitek-2. Molecular characterization included beta-lactamase detection by PCR, MLST, PFGE, and identification of E. coli phylogroups by Clermont protocol.Results: This study included thirty-six hemodialysis patients and 90 of their household contacts.Colonization by BR-GNB occurred in 58.3% of patients and 22.2% of household contacts. The main beta-lactamase detected was CTX-M group-1 (40.5%). In three of the nine homes that had more than one colonized individual, a genetic relationship was found. MLST showed a high diversity in E. coli isolates, and the most frequent phylogroups were B1 and B2. Conclusion:These results show a high frequency of colonization in our population, and the presence of potentially pathogenic BR-GBN not only in hospitals but in the community. This highlights the importance of populations in transit between the two environments, and the need to prevent the spread of bacterial resistance outside hospitals.

Introducción: La resistencia bacteriana es una problemática multifactorial, donde otros escenarios diferentes al hospitalario han cobrado gran importancia. Objetivo: Determinar la presencia de bacilos Gram negativos resistentes a betalactámicos de importancia clínica en aguas residuales de un hospital de alta complejidad de la ciudad de Medellín, Antioquia. Materiales y métodos: Estudio descriptivo de corte transversal. Entre noviembre y diciembre de 2018 se realizaron dos muestreos en dos efluentes de agua residual de un hospital de alta complejidad. Las bacterias fueron aisladas empleando medios cromogénicos y posteriormente se realizó caracterización molecular de betalactamasas empleando PCR. La identificación bacteriana y la susceptibilidad se llevaron a cabo por métodos automatizados. Resultados: Noventa aislados fueron obtenidos, de los cuales el 78,90% (n=71) portaban al menos un gen que codificaba para BLEE ó penicilinasas; y el 78,90% (n=71) al menos un gen para carbapenemasas. Citrobacter freundii fue la bacteria predominante (30% n=12), seguida de Klebsiella pneumoniae (25% n=10). En todos los aislados seleccionados se encontró Multidrogorresistencia (MDR) (100% n=40). Conclusión: La alta presencia de bacterias resistentes a betalactámicos en aguas residuales hospitalarias evidencia la necesidad de implementar estrategias de manejo de estos desechos, dado el riesgo potencial para la transmisión y diseminación de bacterias resistentes.