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A new TEM-derived extended-spectrum beta-lactamase (TEM-91) with an R164C substitution at the omega-loop confers ceftazidime resistance.

ABSTRACT: A new plasmid-mediated TEM-derived extended-spectrum beta-lactamase, TEM-91, was identified in a ceftazidime-resistant (MIC, >128 microg per ml) Escherichia coli strain isolated in 1996 in Japan. TEM-91 has three amino acid substitutions, R164C, M184T, and E240K, compared with TEM-1 penicillinase. The isoelectric point (pI), K(m), and k(cat) of TEM-91 for ceftazidime were 5.7, 179 microM, and 29.0 s(-1), respectively. The K(i) of clavulanic acid for ceftazidime hydrolysis was 30.3 nM.

SUBMITTER: Kurokawa H

PROVIDER: S-EPMC182605 | biostudies-literature | 2003 Sep

REPOSITORIES: biostudies-literature

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A new TEM-derived extended-spectrum beta-lactamase (TEM-91) with an R164C substitution at the omega-loop confers ceftazidime resistance.

Kurokawa Hiroshi H Shibata Naohiro N Doi Yohei Y Shibayama Keigo K Kamachi Kazunari K Yagi Tetsuya T Arakawa Yoshichika Y

Antimicrobial agents and chemotherapy 20030901 9

A new plasmid-mediated TEM-derived extended-spectrum beta-lactamase, TEM-91, was identified in a ceftazidime-resistant (MIC, >128 microg per ml) Escherichia coli strain isolated in 1996 in Japan. TEM-91 has three amino acid substitutions, R164C, M184T, and E240K, compared with TEM-1 penicillinase. The isoelectric point (pI), K(m), and k(cat) of TEM-91 for ceftazidime were 5.7, 179 microM, and 29.0 s(-1), respectively. The K(i) of clavulanic acid for ceftazidime hydrolysis was 30.3 nM. ...[more]

PMID: 12937007

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