Predictors of rectal carriage of carbapenemase-producing Gram-negative bacteria in general wards: A case–control study

• Transfer from another hospital and ICU stay within six months predicted CPB carriage. • Length of hospitalization and antibiotic use also predicted CPB carriage. • 36% of rectal swabs came from patients without ICU or inter-hospital transfer. • 16.8% had no hospitalization in six months, lacking conventional risk factors. • CPB carriage must be considered in general wards of tertiary care hospitals. Rectal carriage of carbapenemase-producing Gram-negative bacteria (CP-GNB-RC) increases the risk of invasive infections and horizontal transmission. This study aimed to identify predictors of CP-GNB-RC in hospitalized patients. A case–control study was conducted in a 300-bed hospital in Santa Fe, Argentina, between 2022 and 2023. Cases and controls were randomly selected and included in a 1:2 ratio. A multivariate binary logistic regression model was built using variables significant in univariate analysis ( p < 0.05). Among 258 patients, 34.5% yielded at least one CP-GNB. Most isolates were Klebsiella spp. (79.0%) and 56.0% produced KPC. In the multivariate analysis, intensive care admission in the past 6 months (OR 3.61), patient transfer from another hospital (OR 2.89), antibiotic exposure (OR 2.34), and length of hospital stay (OR 1.05) were the only independent predictors of CP-GNB-RC. These findings may inform infection control strategies and antimicrobial stewardship interventions in our region. La colonización rectal por bacterias Gram-negativas productoras de carbapenemasas (CR-BGN-PC) aumenta el riesgo de infecciones invasivas. Se realizó un estudio de casos y controles en un hospital de Santa Fe (Argentina) entre 2022 y 2023 para identificar predictores de CR-BGN-PC. Se seleccionaron casos y controles de forma aleatoria en proporción 1:2. Se construyó un modelo de regresión logística binaria utilizando las variables con p < 0,05 en el análisis univariado. El 34,5% del total de pacientes evaluados (n = 258) presentó al menos una BGN-PC. Klebsiella spp. predominó entre los aislamientos (79,0%) y el 56,0% produjo KPC. En el análisis multivariado, los predictores de CR-BGN-PC fueron la estadía en cuidados críticos (menor de 6 meses; OR 3,61), la derivación desde otro hospital (OR 2,89), la exposición a antibióticos (OR 2,34) y los días de hospitalización (OR 1,05). Esta información podría orientar las estrategias de control de infecciones y de optimización del uso de antimicrobianos en nuestra región.