Open AccessTwo novel transferable extended‐spectrum β‐lactamases from Klebsiella pneumoniae in Tunisia
Author(s) -
Ben Redjeb S.,
Fournier G.,
Mabilat C.,
Ben Hassen A.,
Philippon A.
Publication year - 1990
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.1574-6968.1990.tb13831.x
Subject(s) - klebsiella pneumoniae , microbiology and biotechnology , klebsiella , biology , escherichia coli , genetics , gene
Two novel β‐lactamases conferring multiresistance to antibiotics including oxyimino β‐lactams have been identified in two nosocomial K. pneumoniae strains isolated in Tunis in 1986 and 1988. Both enzymes were encoded by ca. 150‐kilobase plasmids. Donor and transconjugant strains producing these enzymes exhibited highly similar pattern of resistance (CTX phenotype) to β‐lactams including penicillins and oxyimino β‐lactams e.g. cefotaxime, ceftriaxone, ceftazidime, and aztreonam. High and variable synergy (16 to 1066‐fold) was obtained when combined to 0.1 μg/ml of clavulance (β‐lactamase inhibitor). The isoelectric points of these two enzymes were 5.4 and 6.4. These β‐lactamases differed from TEM types by hydrolysis for cefotaxime or ceftriaxone but were inhibited by clavulanate and cloxacillin. DNA hybridization studies suggested that the genes of these enzymes may be derived from genes encoding TEM‐type enzymes.