Effect of spacer sequences between blaCTX-M and ISEcp1 on blaCTX-M expression
Ma, Ling and Siu, Leung Kris and Lu, Po-Liang,, 60, 1787-1792 (2011),
doi = https://doi.org/10.1099/jmm.0.033910-0,
publicationName = Microbiology Society,
issn = 0022-2615,
abstract= Spacer sequences of 42 and 127 bp, respectively, between the ISEcp1 insertion sequence and bla CTX-M have been observed in Klebsiella pneumoniae. However, it is not known whether different spacers upstream of bla CTX-M and a promoter within the 127 bp spacer influence cephalosporin resistance. Three recombinant plasmids with different spacers and with or without ISEcp1 were constructed to compare bla CTX-M-3 expression and susceptibility to cephalosporins. Our experiment revealed enhanced bla CTX-M-3 expression and a relatively high level resistance to cefotaxime and cefepime in recombinant plasmid IS42CTX-M-3, which contained ISEcp1 and the 42 bp spacer. A minor difference in bla CTX-M-3 expression was observed in recombinants IS127CTX-M-3 and 127CTX-M-3, which contained a 127 bp spacer with or without ISEcp1, respectively. In conclusion, the promoter within ISEcp1 and a shorter spacer (42 bp but not 127 bp) between ISEcp1 and bla CTX-M are necessary for high-level bla CTX-M-3 expression.,
language=,
type=