Characterisation of a unique ceftazidime-hydrolysing beta-lactamase, TEM-E2.
A strain of Klebsiella oxytoca, originally isolated in Liverpool in 1982, has been found to produce a novel transferable beta-lactamase, TEM-E2. This enzyme confers resistance to ceftazidime and focused as a doublet band with an iso-electric point (pI) of 5.3. The strain also produced the TEM-1 beta-lactamase. Both TEM-1 and TEM-E2 beta-lactamases were encoded by a transferable 103 kb plasmid; these two enzymes also had similar molecular weights, were inhibited by clavulanic acid, and hydrolysed ampicillin, carbenicillin and cephaloridine at similar rates. However, unlike the TEM-1 enzyme, the TEM-E2 beta-lactamase hydrolysed ceftazidime and cefotaxime with similar efficiency, although it conferred much greater resistance to ceftazidime in the host strain. This is the earliest documented example of a TEM-like enzyme which confers transferable resistance to ceftazidime and related cephalosporins.
Department of Bacteriology, Medical School, University of Edinburgh.
D J
DJ
Payne
M S
MS
Marriott
S G
SG
Amyes
D002439:Cefotaxime / Q000378:metabolism; D002442:Ceftazidime / Q000378:metabolism* / Q000494:pharmacology; D002511:Cephalosporins / Q000378:metabolism / Q000494:pharmacology; D019818:Clavulanic Acid; D002969:Clavulanic Acids / Q000494:pharmacology; D003227:Conjugation, Genetic; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D006801:Humans; D006868:Hydrolysis; D007231:Infant, Newborn; D007709:Klebsiella / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D010406:Penicillins / Q000378:metabolism / Q000494:pharmacology; D010957:Plasmids; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
D002511:Cephalosporins; D002969:Clavulanic Acids; D010406:Penicillins; D065093:beta-Lactamase Inhibitors; D019818:Clavulanic Acid; D002442:Ceftazidime; D001618:beta-Lactamases; C056342:beta-lactamase TEM-2; D002439:Cefotaxime