Hidden in Plain Sight: Ralstonia mannitolilytica as a Rare Cause of Urinary Tract Infections

Children admitted to hospitals have been shown to frequently suffer from urinary tract infections (UTIs), with Escherichia coli being the most common cause. Ralstonia mannitolilytica is commonly found in plants, soil, and water sources. Since Ralstonia species are resistant to many antimicrobials, such as carbapenems, treating an infection with R. mannitolilytica is challenging. We present an unusual case of a five-month-old infant with a posterior urethral valve whose urine culture showed the growth of a rare organism called R. mannitolilytica. UTIs associated with R. mannitolilytica are still relatively uncommon. With its high mortality rates, despite antibiotic treatment, this unusual organism needs to be considered in the immunocompromised population presenting with rapidly progressing infections.