Macrolides: a novel risk factor for carbapenemase-producing Enterobacterales in intensive care units

Carbapenemase-producing Enterobacterales (CPE) have emerged as a substantial cause of morbi-mortality worldwide, with a prevalence of approximately 5% in areas with high endemicity. However, available data may not be representative of developing countries, such as Ecuador. In this study, the incidence of CPE in Ecuador and risk factors for infection/colonisation were evaluated.

A prospective cohort study was performed from February to April 2016 in seven intensive-care units of Guayaquil, Ecuador. Samples were processed according to the Centers for Disease Control and Prevention laboratory protocol and the CHROMagar mSuper CARBA agar method. Resistance to carbapenems was defined according to Clinical and Laboratory Standards Institute breakpoints. A modified carbapenemase inactivation method was used to identify carbapenamase production phenotypically with molecular confirmation by multiplex polymerase chain reaction.

In total, 640 patients were enrolled. The incidence of CPE was 36.4% (N = 233). A multivariate analysis indicated that several factors were associated with CPE acquisition, included a long intensive care unit stay (OR 1.05; 95% CI 1.03-1.08; p < 0.01), tracheostomy (OR 3.52; 95% CI 1.90-6.75; p < 0.01), hospitalisation 3 months prior to admission (OR 2.07; 95% CI 1.17-3.71; p < 0.01), vancomycin use (OR 3.31; 95% CI 2.02-5.18; p < 0.01), and macrolide use (OR 3.31; 95% CI 1.43-7.76; p < 0.01).

Macrolide use was a risk factor for CPE acquisition. This association should be evaluated further, especially in developing countries.