Pediatric Vulvovaginitis Caused by Extended-Spectrum Beta-Lactamase-Producing Escherichia coli: A Case Report

Abstract

Pediatric vulvovaginitis is one of the most common gynecological problems in prepubertal girls and is often attributed to nonspecific or fungal causes. However, recent evidence shows that multidrug-resistant aerobic enteric bacteria are emerging as significant pathogens, complicating diagnosis and limiting treatment options. Extended-spectrum β-lactamase (ESBL)–producing Escherichia coli is a particular concern because resistance to commonly prescribed antibiotics restricts effective therapy in children.

We report the case of a 10-month-old female who presented with abdominal distension, fever, and purulent greenish vaginal discharge accompanied by erythema and perineal irritation. Initial topical antifungal therapy proved ineffective. Laboratory investigations revealed leukocytosis and elevated inflammatory markers. Vaginal swab microscopy demonstrated abundant polymorphonuclear leukocytes and Gram-negative bacilli. Aerobic culture yielded lactose-fermenting colonies identified as E. coli through biochemical assays, MALDI-TOF mass spectrometry, and 16S rRNA sequencing. Antimicrobial susceptibility testing revealed resistance to third-generation cephalosporins, aminoglycosides, and aztreonam, while maintaining susceptibility to meropenem and ertapenem, confirming ESBL production. The patient responded well to intravenous meropenem combined with oral fluconazole and topical miconazole, showing marked clinical improvement within five days.

This case underscores the susceptibility of prepubertal girls to aerobic vaginitis, the need for accurate microbiological diagnosis, and the therapeutic challenges posed by ESBL-producing organisms. It also highlights broader health implications, emphasizing antimicrobial stewardship, infection prevention, and caregiver education.