Microbiological characterization and clinical outcomes of carbapenem-resistant enterobacterales infections in a paediatric hospital in Mexico.

backgroundThe mortality rate in children with carbapenem-resistant Enterobacterales (CRE) infections can exceed 50%, depending on the origin of the infection, antimicrobial resistance, comorbidities, and drug availability. This study aimed to describe the clonal diversity of CRE, as well as the clinical characteristics, treatments, and outcomes of the infections in pediatric patients in a tertiary care hospital in Mexico.

methodsThis single-centre observational study was conducted in a paediatric tertiary care hospital, in which 40 CRE isolates were included; the susceptibility profile and phenotypic and genotypic detection of carbapenemases were determined. The sequence type (ST) was obtained by multilocus sequence typing, and the clinical records were reviewed to obtain clinical information.

resultsKlebsiella spp. and Escherichia coli were the predominant species (35 and 29%, respectively). A total of 57.5% of the isolates were susceptible to ceftazidime-avibactam (CZA). 70% of the isolates were carbapenemase-producing Enterobacterales (CPE). The most frequent enzymes were NDM-like (52%), OXA-48 like (24%), KPC-2 (17%), and VIM-2 (7%); NDM-5 and OXA-48 were detected in an E. coli isolate. 36% of the CRE isolates were considered high-risk clones (HRC); E. coli ST167 and K. pneumoniae ST15 and ST25 were the most frequent clones. The most common infections were pneumonia (25%) and bacteraemia (17.5%). 90% of the patients had some underlying disease. Empirical treatment was administered to 34 patients, 19 in monotherapy and 15 in combined therapy. A total of 47.5% of the patients died. Carbapenemase production was related to admission to the intensive care unit (ICU) (p = 0.043) and the presentation of complications (p = 0.032). Patients who experienced complications required admission to the ICU (p = 0.02) and exhibited higher mortality rates (p = 0.046).

conclusionsK. pneumoniae was the predominant species identified. At least one carbapenemase was detected in 70% of the CRE isolates; the most frequent enzyme was NDM. This study reports the first isolations of E. coli ST167-NDM-5 and K. pneumoniae ST231-NDM-1 in Mexican pediatric patients. Pneumonia was the most frequent infection. The lack of availability of new antimicrobials in our hospital limits therapeutic options, which may have contributed to the high mortality rate (47.5%) observed. CLINICAL TRIAL: Not applicable.