Stenotrophomonas maltophilia Bloodstream Infections in Children and Clinical Outcomes of CeftazidimeTreatment

Objective: Stenotrophomonas maltophilia can cause opportunistic and healthcare-associated infections in hospitalized patients. It differs from other gram-negative pathogens due to intrinsic resistance to various antimicrobials, especially carbapenems. Treatment of S. maltophilia infections in children is more challenging than in adults due to possible adverse events of most commonly recommended antimicrobials such as trimethoprim-sulfamethoxazole (TMP-SMX) and fluoroquinolones. Studies on the treatment options for S. maltophilia infections in children are limited. This study aimed to evaluate the demographic, clinical characteristics, and mortality rates of S. maltophilia bloodstream infections (BSI) and identify ceftazidime therapy outcomes. Material and Methods: A retrospective study was conducted to evaluate pediatric patients with S. maltophilia BSI between January 2021 and December 2021. Asymptomatic patients who had positive blood cultures for S. maltophilia were excluded because of the possibility of contamination. Results: A total of 33 patients with S. maltophilia BSI were evaluated. Twenty (60.6%) patients were included in the ceftazidime group and 13 (39.4%) patients were included in the other antimicrobials [(TMP-SMX) and ciprofloxacin] group. Median age of the patients was eight months (three days-17.5 years). The most common underlying disease was congenital heart disease (27.3%), followed by chronic neurological/neuromuscular disorders (18.2%) and esophageal atresia (9.1%). Twenty-five (78.8%) patients had a central venous catheter, 14 (42.6%) patients had surgery, and 29 (87.9%) patients had a history of prior pediatric intensive care unit admission. Prior antimicrobial treatment was administered to 26 (78.8%) patients before BSI onset. The rates of ceftazidime, ciprofloxacin, levofloxacin, and TMP-SMX susceptibility were 83.9%, 93.3%, 93.5%, and 65.6%, respectively. In the ceftazidime group, clinical success rate was 93.8% and there were no deaths within 30 days. In the other antimicrobials group, clinical success rate was 84.6% and two patients died within 14 days. However, there were no statistically significant differences in clinical success and mortality rates between groups. Conclusion: S. maltophilia has intrinsic resistance to carbapenems and other antimicrobials, and treatment options for these infections are limited. We suggest that ceftazidime could be an alternative antimicrobial agent in pediatric patients with S. maltophilia BSI when other options could not be used.