Bacteriuria in Paediatric Oncology Patients: Clinical Features, Distribution and Antimicrobial Susceptibility of Bacterial Pathogens at University Hospital Centre Zagreb, Croatia over a 4-Year Period.

Bacteriuria in paediatric oncology patients have not been well studied. This retrospective study analysed clinical features, distribution and antimicrobial susceptibility of bacterial pathogens cultured from urine in paediatric oncology patients over a 4-year period (2019-2022). A total of 143 episodes of bacteriuria were documented in 74 patients. Neutropenia was present in 17.5% (25/143), symptoms in 25.9% (37/143) and urinary catheter in 7.0% (10/143) episodes. Symptomatic bacteriuria episodes were statistically significantly more frequent in patients with neutropenia (p = 0.0232). The most common bacterial pathogens were Escherichia coli (n = 49; 32.2%), Klebsiella spp. (n = 34; 22.4%), Pseudomonas aeruginosa (n = 22; 14.5%) and Enterococcus spp. (n = 21; 13.8%). Extended-spectrum ß-lactamases-producing (ESBL) Enterobacterales were found in 11 episodes (11/143; 7.7%) with the highest proportion among Klebsiella pneumoniae isolates (n = 7/34; 20.6%). No carbapenem-resistant Enterobacterales, multidrug-resistant P. aeruginosa or vancomycin-resistant Enterococcus spp. were found. The most important novelties are demonstrating P. aeruginosa as one of the prominent bacteriuria pathogens in this patient population, presence of ESBL isolates and carbapenem-resistant P. aeruginosa later during hospitalization highlights the need for appropriate antimicrobial treatment. However, because of the small number of symptomatic patients, further studies are needed to clarify the importance of including urine culture in the diagnostic process in patients with febrile neutropenia.

Bloodstream Infections in Pediatric Oncology Patients: Bacterial Pathogen Distribution and Antimicrobial Susceptibility at the University Hospital Centre Zagreb, Croatia-A 5-Year Analysis.

The epidemiology of bacterial pathogens causing bloodstream infections (BSIs) in pediatric hematology/oncology patients is changing and resistance to antimicrobial agents is globally spread. We retrospectively assessed demographic, clinical, and microbiologic data of BSIs during a 5-year period at a pediatric hematology/oncology unit from January 1, 2017, to December 31, 2021, at the University Hospital Centre Zagreb, Zagreb, Croatia. In 66 pediatric patients with malignancies, 93 BSI episodes were registered and 97 bacterial isolates were cultured. The Gram-positive versus Gram-negative ratio was 67 (69.1%) versus 30 (30.9%). Coagulase-negative staphylococci (48; 49.6%) were the most frequent isolates, followed by Enterobacterales (17; 17.5%) and Staphylococcus aureus (6; 6.2%). Multidrug resistance isolates included extended spectrum ß-lactamase producers (n=3). Resistance rates to piperacillin/tazobactam, cefepime, and meropenem in Gram-negative isolates were 15.4%, 14.3%, and 0.0%, respectively. Gram-positive bacteria are the most common cause of BSI in our patients. Resistance rates to piperacillin/tazobactam and cefepime in Gram-negative isolates make meropenem a better choice for empirical antimicrobial treatment. As national and hospital data may differ, the surveillance of pathogen distribution and antimicrobial susceptibility in pediatric hematology/oncology wards is necessary to adjust empirical treatment accordingly.