The Surveillance of Bloodstream Infections in a German Pediatric Cancer Unit During a 5-Year Period: Microbial Spectrum, Antimicrobial Susceptibility and Effectiveness of Preventive Taurolidine Lock

BACKGROUND: The aim of the study was to evaluate the spectrum and the antimicrobial susceptibility of microorganisms causing bloodstream infections (BSIs) in a cohort of patients of a pediatric cancer unit. In addition, we evaluated the effectiveness of preventive antimicrobial lock therapy with taurolidine-citrate solution in reducing BSI rates. METHODS: We prospectively assessed demographic, clinical and microbiological data of BSIs during a 5-year period from January 2019 to December 2023. Preventive lock treatment with instillation of taurolidine-citrate solution into the central venous catheter (CVC) was performed from January 2019 to April 2022, interrupted from May to December 2022 and, after a suspected increase in BSI episodes, reintroduced from January 2023. RESULTS: In 45 patients, a total of 57 BSI episodes were recorded and 60 microorganisms were cultured. The most frequently isolated bacteria belonged to Staphylococcus spp. (n = 20, 33.3%) and Enterobacterales (n = 17, 28.3%). Regarding the antimicrobial susceptibility, all Gram-positive bacteria were susceptible to vancomycin. Among the Gram-negative bacteria, only 4 isolates (17.4%) showed a resistance against piperacillin/tazobactam and only 1 isolate a resistance against meropenem (4.3%). Incidence of BSIs was highest from May to December 2022 (19.6 per 100 patient months; 95% confidence intervals: 11.0-32.4 per 100 patient months) when CVCs were locked with saline instead of taurolidine-citrate solution. CONCLUSIONS: In this study, Staphylococcus spp. and Enterobacterales were the most frequently isolated microorganisms. The lock of CVCs with taurolidine apparently contributed to the prevention of BSIs in the above-mentioned patients.