Community-Acquired Infection Caused by mcr-1 and blaOXA-48-Producing Escherichia coli: A Case Highlighting Limitations of Selective Susceptibility Testing.

Selective susceptibility testing may fail to detect high-priority resistance in community-acquired Escherichia coli infections, as shown by a case involving mcr-1 and blaOXA-48 producers.

• Why it matters: Accurate detection of antimicrobial resistance is crucial for effective treatment and preventing community spread, but current testing methods may overlook critical resistance markers in high-resistance settings.
• What they did: The study reports a case of necrotic metastatic inguinal lymphadenopathy caused by two E. coli isolates, including one blaOXA-48 producer, with initial testing delaying resistance recognition.
• The result: This case emphasizes the need for context-adapted susceptibility reporting to improve detection of resistance determinants and support both antimicrobial stewardship and resistance surveillance.