Multidrug-Resistant Organisms Colonization in Pediatric HCT Patients: Prevalence and Outcomes

Background

Infections remain a significant clinical challenge in patients undergoing chemotherapy and hematopoietic cell transplantation (HCT). The emergence of multidrug-resistant organisms (MDROs) has further complicated the management for patients. The aim of the study is to evaluate the prevalence of MDRO colonization by Enterobacterales, Pseudomonas spp and Acinetobacter spp, detected by rectal swab surveillance culture (RSSC), evaluating the clinical characteristics and outcomes of pediatric patients undergoing HCT.

Methods

Retrospective analytic observational study, from January 2019 to December 2023. We included patients who were 0 to 18 years of age, underwent HCT, in our pediatric hospital in Brazil. From the RSSC positive results collected at the HCT unit, we analyzed the epidemiological data and outcomes in the first 30 days after transplantation.

Results

We analyzed 98 positive RSSCs performed in 75 patients, identifying 107 multidrug-resistant organisms (MDROs). The majority of patients were male (65.3%). Allogeneic HCT accounted for 93.3% of cases, predominantly indicated for leukemia (53.3%), followed by hemoglobinopathies and bone marrow aplasia (20%).

Enterobacteriaceae were the most frequently identified bacteria in RSSCs (89.9%), with Escherichia coli (36.7%) and Klebsiella sp. (35.7%) being the most common. Resistance mechanisms most common included the production of extended-spectrum beta-lactamases (ESBL; 68%) and serine-beta-lactamases (17.4%).

Febrile episodes occurred in 93.3% of patients, with blood cultures collected during the febrile period. Among 21 samples with bacterial identification, 85% revealed gram-positive bacteria. Of the gram-negative bacteria cases (33.5%), only two matched the bacteria identified in RSSCs. No deaths were recorded during the study period.

Conclusion

The study highlights the predominance of gram-negative bacteria, particularly Enterobacteriaceae, in positive RSSCs, with significant resistance mechanisms such as ESBL. Despite the presence of MDROs, febrile episodes and bloodstream infections were infrequent, and no mortality was observed during the study period. RSSC results must be carefully interpreted when applying to the management of child with FN.