Associate Professor of Pharmacology and Pediatrics Universite de Montreal Faculty of Medicine Montréal, Quebec, Canada
Background: Prophylactic probiotics is associated with improved outcomes in preterm infants including reduced rates of necrotizing enterocolitis (NEC). However, microorganisms contained in probiotics formulations have the potential of causing bacteremia in highly vulnerable infants. Objective: To describe the incidence and the clinical characteristics of infants presenting with Lactobacillus sp. and Bifidobacterium sp. bacteremia, after having received probiotics. Design/Methods: This single-center retrospective study was conducted at a neonatal intensive care unit within a tertiary pediatric hospital. We included all infants with ≥1 positive Lactobacillus sp. or Bifidobacterium sp. blood culture between Jun 2011 and Dec 2022, and who have received ≥1 dose of FlorababyTM prior to bacteremia. FlorababyTM is a blend of probiotics containing 5 strains of live bacteria and is routinely administered to infants less than 32+6 weeks gestational age or birth weight less than 1,500g. Per our local standard of care, probiotics are started at the first enteral feed until 34 weeks’ postmenstrual age. We estimated the incidence of bacteremia among the total number of infants who were prescribed probiotics during the same period. We have reviewed the selected infants’ charts for clinical and microbiological characteristics, and outcomes. All bacterial isolates were recovered using VersaTREKTM automated blood culture system. Most specie level identification and susceptibility testing were performed in the provincial reference microbiology laboratory. Results: Among 2109 infants who were prescribed probiotics, 12 (0.6%) had ≥1 positive blood culture for either Lactobacillus sp (n=3) or Bifidobacterium sp (n=9). Infants had a median (range) postnatal age of 11 (2-65) days at the time of infection (Table 1). Ten isolates were identified to the specie level showing that the strains were consistent with FlorababyTM’s ingredients (Table 2). Susceptibility testing was performed on 11 isolates and all were susceptible to penicillin. Eight infants (67%) had either a NEC (n=6) or a spontaneous intestinal perforation (n=2) at the time of infection. Two bacteremic infants died following intestinal perforation.
Conclusion(s): Lactobacillus sp. or Bifidobacterium sp. bacteremia was rare in preterm infants who were prescribed probiotics. Infection only affected extremely low birth weight infants and the majority had a concomitant gastrointestinal complication. Our findings suggest that, in preterm infants receiving probiotics, empiric antibiotic coverage for sepsis should include a penicillin derivative.
.png)
.png)