Integrating diagnostic approaches in bacterial infant meningitis caused by a non-K1 Escherichia coli: a case report
Infant meningitis, particularly caused by Escherichia coli, remains a life-threatening condition, especially in premature and low-weight infants. Infections of the central nervous system can be fatal, necessitating prompt diagnosis and appropriate treatment. Acute infections caused by various pathogens, including E. coli, often present with similar clinical symptoms. Rapid identification of pathogens and their antimicrobial resistance mechanisms is critical for timely and effective treatment. We report a case of an 8-month-old patient, who presented with fever, diarrhea, and convulsive seizures, subsequently diagnosed with meningitis. Despite initial empirical treatment with ceftriaxone, the patient's condition worsened. At Bambino Gesù Children's Hospital, molecular diagnostic tools, including the FilmArray Meningitis/Encephalitis and Blood Culture Identification panels, were employed. Although the Meningitis Panel did not detect any pathogens due to the lack of the specific bacterial target, the off-label use of the Blood Culture Identification panel identified a non-K1 Escherichia coli strain carrying the CTX-M resistance gene, an extended-spectrum beta-lactamase (ESBL). Despite the rapid diagnostic approach and adjustment of antibiotic therapy, the patient succumbed to the infection due to the strain's high virulence and multidrug resistance. Whole genome sequencing further characterized the strain, revealing its belonging to the ST131 clone, a highly resistant and virulent strain associated with sepsis. This case highlights the importance of integrating advanced molecular diagnostics, such as whole genome sequencing, with traditional methods to improve pathogen detection, especially in cases of emerging resistant strains not covered by standard diagnostic panels. It also emphasizes the need for continuous adaptation of diagnostic tools to include non-K1 E. coli strains for more comprehensive and timely meningitis diagnosis.