IS Ecp1B -Mediated Transposition of bla _CTX-M in Escherichia coli

Abstract

Several expanded-spectrum ␤-lactamase bla CTX-M genes are associated with ISEcp1-like elements in Enterobacteriaceae. We found that ISEcp1B was able to mobilize the adjacent bla CTX-M-19 gene by a transpositional mechanism in Escherichia coli by recognizing a variety of DNA sequences as right inverted repeats.

Dissemination of Clonally RelatedEscherichia coliStrains Expressing Extended-Spectrum β-Lactamase CTX-M-15

“…An evolutionary convergent relationship among B2 genetic background and IncFII plasmids cannot be ruled out and should be studied because it might explain successful dissemination of CTX-M-15 plasmids within this E. coli lineage. In addition, our study is one of the few that have identifi ed bla ESBL genes in the chromosome, which might respond either to plasmid integration or transposition driven by ISEcp1 located upstream from the bla CTX-M-15 gene (25,39,40). In conclusion, worldwide dissemination of bla CTX-M-15 is driven by B2 or D E. coli clones associated mainly with urinary tract infections or IncFII plasmids containing a multiple antimicrobial drug-resistance platform that contributes to spread of CTX-M-15.…”

Complete Nucleotide Sequences of Plasmids pEK204, pEK499, and pEK516, Encoding CTX-M Enzymes in Three Major Escherichia coli Lineages from the United Kingdom, All Belonging to the International O25:H4-ST131 Clone

“…The ISEcp1-bla CTX-M-3 element of pEK204 was flanked by 5-bp direct repeats of TATTG, consistent with ISEcp1-mediated transposition, which prefers AT-rich target sequences (29). Despite disruption, the Tn3 transposase (tnpA) gene on pEK204 was still predicted to encode a protein of 999 amino acids, comprising 970 (ca.…”

Modes and Modulations of Antibiotic Resistance Gene Expression

“…The contribution of such a promoter by ISEcp1 to the expression of CTX-M-type extended-spectrum ␤-lactamase genes has been reported in several instances. The suggested promoter for bla CTX-M-15 on the right end of ISEcp1 (122) as well as the suggested mode of ISEcp1-supported gene mobilization by one-ended transposition (241a) have been validated experimentally for bla CTX-M-17 (41) and for bla CTX-M-19 (201,203). Considering that ISEcp1 or ISEcp1-like elements are present upstream from genes of multiple other CTX-M-and also CMY-type enzymes in various species of Enterobacteriaceae (see references 36, 73, 150, and 203 and references therein), this element may be among those most largely involved in the expression of extendedspectrum ␤-lactamase genes.…”

“…More recently identified cassettes are associated with genes that mediate resistance to rifampin and quinolones and increasingly also with genes encoding extended-spectrum ␤-lactamases and carbapenemases (82,88,136,200,203,208,261,264). Transcriptional control of resistance gene expression in class 1 integrons.…”