A rare pathogen caused urinary tract infection in child with congenital anomalies of kidney and urinary tract: case report.

was previously considered an environmental organism in soil, water, and plants. However, several cases of human infection have recently been reported in association with , some of which have been life-threatening. Most cases were in adults with reduced immunity, with few cases in children. To our knowledge, there have only been two reported cases of urinary tract infection (UTI) caused by in children, including one case of cystitis. Here, we present the first case of UTI caused by with congenital anomalies of kidney and urinary tract (CAKUT) in a 4-month-old male infant. The patient presented to the emergency department with fever and was diagnosed with UTI. We started third-generation cephalosporins empirically for gram-negative bacteria in the urine, presuming infection with . On day 1, the patient's fever resolved immediately. On day 2, urine culture was positive for a rare pathogen, , and we narrowed antibiotics to first-generation cephalosporins. The patient's fever did not return and he was discharged on day 7. The patient was seen in the clinic 1 week after discharge, with complete resolution of symptoms. Magnetic resonance urography and dynamic renal scintigraphy performed 2 months after discharge revealed severe bilateral hydronephroureter and obstruction of urine flow in the right kidney. As of 6 months after UTI onset, we have continued low-dose cephalexin (10 mg/kg) to prevent the recurrence of UTI and there has been no recurrence. As in this case, children with UTI caused by may be associated with CAKUT; therefore, we should actively screen to detect CAKUT. Patients with CAKUT are at high risk of UTI recurrence, so long-term use of unnecessary broad-spectrum antibiotics should be avoided to prevent antimicrobial resistance. However, infection is sometimes life-threatening. Hence, it is also important to use sufficiently strong antibiotics for an appropriate period. Although the optimal management of infection in children has not been clearly established, we suggest that we can treat UTI caused by mainly using first-generation cephalosporins.