Retrospective Analysis of Paenibacillus urinalis Cultures Primarily Obtained from Sterile Sites in a Pediatric Population from Turkey

In the literature, there is a limited number of case reports of Paenibacillus urinalis in adults. However, there is no information available regarding P. urinalis infection in children and infants. Paenibacillus growth in blood and sterile site cultures is generally considered contamination; it is unclear whether P. urinalis is the true cause of the infection. In this retrospective study, we aimed to clinically evaluate P. urinalis growth in the blood cultures of children at a tertiary referral hospital over a 5.5-year period, with identification performed using the MALDI-TOF MS method. A total of 170 hospitalized children showed P. urinalis growth in sterile site cultures (blood: 162; catheter: 7; CSF: 1), with forty percent of all growth occurring in only three wards (neonatal intensive care unit, hematology, oncology). Of 170 cultures, 5 (2.9%) showed further P. urinalis growth in control cultures, which could be considered significant. In cases with a second culture, the average growth time (time to positivity) was relatively short, at 24 + 7 h (mean + SD, min-max: 17–33 h). No mortality was observed in any case. Evaluations were conducted by the Hospital Infection Control Committee to determine the source of P. urinalis contamination. P. urinalis growth was detected in 33% of samples taken from clean, packaged linens before use; 53% of ambient air cultures; and 65% of hospitalized patient skin swabs. In conclusion, P. urinalis blood culture growths are primarily considered contamination; however, these growths should be carefully evaluated in risk groups (especially those admitted in neonatal intensive care units and young infants less than 3 months old). In hospitalized patients, clustered growths may be influenced by environmental (such as clean packaged linens and ambient air) and skin colonization.