Genetic and clinical landscape of methicillin-resistant Staphylococcus aureus isolates lacking the mec gene, in Japan.

ABSTRACT:

Objectives

The present study examines methicillin-resistant Staphylococcus aureus isolates lacking mec (MRLM) phenotypic and genotypic traits and clinical features of patients.

Methods

Between October 2021 and February 2023, 13 MRLM isolates were identified among 867 S. aureus clinical isolates and subjected to WGS.

Results

Ten of the 13 MRLMs were resistant to cefoxitin (MICs >4 mg/L), including two that were also resistant to oxacillin. The remaining three isolates were susceptible to both cefoxitin and oxacillin and exhibited typical growth on CHROMagar MRSA. Seven of the 13 isolates harboured the blaZ gene, but the hyperproduction of the β-lactamase encoded by this gene was not predicted. All isolates exhibited low MICs for cefazolin, c

SUBMITTER: Natori T 

PROVIDER: S-EPMC12848829 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature