[Molecular characteristics of beta-lactamase from Klebsiella pneumoniae].
OBJECTIVE
To study the molecular characteristics of beta-lactamase from Klebsiella pneumoniae.


METHODS
Beta-lactamase was prepared from strains of Klebsiella pneumoniae isolated clinically for which the minimal inhibitory concentration (MIC) of cefoperazone had been >or= 8 mg/L and then was reduced by 50% by the addition of sulbatam. The isoelectric points of different beta -lactamases were examined by LKB2117 Multiphor II Electrophoresis System. The molecular weights were examined by polyacrylamide gel electrophoresis. PCR was used to detect the TEM-type genes. The PCR products were sequenced by chemiluminescence.


RESULTS
All four strains of Klebsiella pneumoniae produced more than two kinds of beta-lactamase. TEM-type genes were amplified from all strains. 97% - 98% of the DNA sequence and amino acid sequence of the TEM-type enzymes from 2 strains of Klebsiella pneumoniae were identical with those of TEM-1 enzyme. The isoelectric points of the beta-lactamases ranged from 5.4 to 9.30 and the molecular weights were between 23.0 and 43.0 KD. The beta-lactamases from Klebsiella pneumoniae 99592 and K. pneumoniae 99607 hydrolysed ceftazidine, cefotaxime, and ceftriaxone. The beta-lactamase from K. pneumoniae 99595 had stronger activity against ceftazidime, ceftaxime, and ceftriaxone than that from K. pneumoniae 99607.


CONCLUSIONS
Klebsiella pneumoniae produces TEM-type extended spectrum beta -lactamase against ceftazidine, ceftaxime, and ceftriaxone.
Zhang
Yonglong
Y
Institute of Clinical Pharmacology, Peking University First Hospital, Beijing 100083, China.
Li
Jiatai
J
Zhao
Mingwu
M
D007526:Isoelectric Point; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D008970:Molecular Weight; D016133:Polymerase Chain Reaction; D001618:beta-Lactamases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D001618:beta-Lactamases; C034413:beta-lactamase TEM-1