Emergence of third‐generation cephalosporin‐resistant Enterobacteriacae in a Japanese critical care setting

Extended‐spectrum beta‐lactamases and AmpC beta‐lactamases give resistance to Enterobacteriaceae against cephalosporins, which are important drugs in various clinical settings. Within 5 days, a total of eight strains of Citrobacter freundii and two strains of Escherichia coli, all of which were resistant to third‐generation cephalosporins, were isolated from six different patients in a critical care center. We carried out epidemiological and genetic studies to confirm the situation to be an outbreak by a single strain or a beta‐lactamase‐producing gene.