Article in Japanese

An infant case of urinary tract infection without pyuria caused by Streptococcus agalactiae

Akihiro Umeda^1）, Yui Kajita^1）, Yoshimi Akada^1）, Ikuyou Ito^1）, Hiroyuki Machida^1）, Eri Kiyomiya^1）, Naoko Yoshikawa^1）, Madoka Fujii^1）, Shingo Kobari^1）, Atsushi Isozaki^1）

Streptococcus agalactiae （Group B Streptococcus GBS） is known to cause invasive infections such as sepsis, meningitis, and pneumonia in neonates and infants, but it is rarely a cause of urinary tract infection （UTI）. The patient was a 10-month-old girl who presented with fever. Urinalysis did not reveal pyuria. A catheterized urine smear showed Gram-positive cocci on microscopic examination, leading to suspected UTI, and the girl was admitted for treatment. Later, a urine culture identified GBS, thus confirming that UTI was caused by this organism. During hospitalization, a voiding cystourethrogram （VCUG） revealed bilateral vesicoureteral reflux （VUR）. In cases of UTI caused by Gram-positive bacteria, pyuria may be less apparent. Therefore, even in the absence of pyuria, it is important to perform urine Gram staining and culture when a UTI is suspected.

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1）Department of Pediatrics, Yokohama City Minato Red Cross Hospital

Key words	Streptococcus agalactiae，urinary tract infection, infant
Received	March 30, 2025
Accepted	May 12, 2025

37 (3)：247─251,2025