Plasmid-mediated transfer of CTX-M-55 extended-spectrum beta-lactamase among different strains of Salmonella and Shigella spp. in the Republic of Korea

Abstract We screened 10 CTX-M-55-producing Shigella and Salmonella isolates from a national surveillance in Korea. The bla CTX-M-55 was located on the IncI1 ( n =5), IncA/C ( n =4) and IncZ ( n =1) plasmids, downstream of IS Ecp1 , IS 26 -IS Ecp1 and IS Ecp1 -IS 5 sequences, respectively. These results indicate that CTX-M-55 has disseminated to other bacteria by lateral plasmid transfer.