A double-edged sword of probiotic: Alkalihalobacillus clausii bacteremia in a child.

Invasive infections by the probiotic bacteria are a rare occurrence. We report a case of bacteremia by Alkalihalobacillus clausii in a 5-month-old child with leukocyte adhesion defect. The child had developed recurrent infections, and failure to thrive, requiring multiple hospitalizations. He was being treated with probiotics for diarrheal illness and subsequently developed severe respiratory distress, elevated inflammatory markers and marked leukocytosis. Blood culture grew a Gram-positive bacillus identified as Alkalihalobacillus clausii. Child showed symptomatic improvement after antimicrobial therapy. This case highlights cautious use of probiotics in an immunocompromised host, and early detection of probiotic organisms as pathogens in such cases.