Open Accessβ‐Lactam induction of IS Ecp1B ‐mediated mobilization of the naturally occurring bla CTX‐M β‐lactamase gene of Kluyvera ascorbata
Author(s) -
Nordmann Patrice,
Lartigue MarieFrédérique,
Poirel Laurent
Publication year - 2008
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2008.01359.x
Subject(s) - clavulanic acid , enterobacteriaceae , microbiology and biotechnology , ceftazidime , amoxicillin , plasmid , biology , transposition (logic) , escherichia coli , antibacterial agent , gene , bacteria , antibiotics , pseudomonas aeruginosa , genetics , linguistics , philosophy
IS Ecp1B is an insertion element associated with the emerging expanded‐spectrum β‐lactamase bla CTX‐M genes in Enterobacteriaceae . Because IS Ecp1B ‐ bla CTX‐M positive strains may be identified from humans and animals, the ability of this insertion sequence to mobilize the bla CTX‐M‐2 gene was tested from its progenitor Kluyvera ascorbata to study the effects of amoxicillin/clavulanic and cefquinome as enhancers of transposition. These β‐lactam molecules are administered parenterally to treat infected animals. IS Ecp1B ‐mediated mobilization of the bla CTX‐M‐2 gene from K. ascorbata to a plasmid location in Escherichia coli J53 was studied. Transposition assays were performed with overnight cultures with amoxicillin/clavulanic acid and cefquinome at concentrations expected to mimic those found in feces after parenteral administration (0.4–0.008 mg L −1 and 0.32–0.064 mg L −1 , respectively). Amoxicillin/clavulanic acid and cefquinome did not modify the transposition frequency (1.85±1.7 × 10 −7 ) whereas ceftazidime (0.5 mg L −1 ), used as a control, did (5.2±2.7 × 10 −5 ). Therefore, it is likely that neither amoxicillin/clavulanic acid nor cefquinome concentrations as found in the gut flora may enhance mobilization of the bla CTX‐M genes in Enterobacteriaceae .