Plasmid-mediated extended-spectrum β-lactamase (CTX-M-3 like) from India and gene association with insertion sequence ISEcp1

Abstract

Six non-clonally related enterobacterial isolates producing a same extended-spectrum β-lactamase CTX-M-15 were isolated in 1999 from patients hospitalized in a New Delhi hospital. CTX-M-15 differed from CTX-M-3 by an asparagine to glycine substitution in position ABL238. Its gene was located on large plasmids varying in size. In each case, a same insertion sequence ISEcp1 was identified upstream of the 5′ end of bla_CTX-M-15. Typical −35 and −10 promoter sequences of Enterobacteriaceae were identified in the 3′ end of ISEcp1. The location of ISEcp1 upstream of plasmid-mediated CTX-M-type β-lactamase genes may contribute to their spread or/and their expression.