ACC-1 β-Lactamase–producing Salmonella enterica Serovar Typhi, India

摘要

To the Editor: Typhoid fever, caused by Salmonella enterica sero-var Typhi, is a serious form of enteric fever. In 2000, the worldwide number of typhoid cases was estimated to be >21,000,000, and there were >200,000 deaths from this disease (1).Cipro. oxacin is the fi rst-line drug of choice for treatment of patients with typhoid fever, but there has been an in-crease in strains resistant to cipro. ox-acin (2) and resistance to third-gen-eration cephalosporins has emerged (3). There are sporadic reports of high resistance to ceftriaxone in typhoidal salmonellae (3,4) in which CTX-M-15 and SHV-12 extended spectrum β-lactamases (ESBLs) have been re-ported. To date, there are no reports of AmpC β-lactamases in typhoidal salmonellae. AmpC β-lactamases con-fer resistance to a broad spectrum of β-lactams, which greatly limits thera-peutic options. We investigated an iso-late of S. Typhi by using serotyping, antimicrobial drug susceptibility test-ing, PCR screening for β–lactamase genes, and sequence analysis to con-fi rm the identity of the isolate and the β–lactamase gene involved in confer-ring resistance to this isolate