Skip Navigation



JAC Advance Access published online on August 2, 2007
Journal of Antimicrobial Chemotherapy, doi:10.1093/jac/dkm275
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
60/4/877    most recent
dkm275v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Perilli, M.
Right arrow Articles by Amicosante, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Perilli, M.
Right arrow Articles by Amicosante, G.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2007. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org

Biochemical analysis of TEM-134, a new TEM-type extended-spectrum ß-lactamase variant produced in a Citrobacter koseri clinical isolate from an Italian hospital

Mariagrazia Perilli1, Giuseppe Celenza1, Marianna Fiore1, Bernardetta Segatore1, Cristina Pellegrini1, Francesco Luzzaro2, Gian Maria Rossolini3 and Gianfranco Amicosante1,*

1 Department of Sciences and Biomedical Technologies, University of L'Aquila, L'Aquila, Italy 2 Laboratory of Microbiology, Ospedale di Circolo, Varese, Italy 3 Department of Molecular Biology, University of Siena, Siena, Italy

Received 2 April 2007; returned 22 April 2007; revised 27 June 2007; accepted 29 June 2007

* Corresponding author. Tel: +39-0862-433455; Fax: +39-0862-433433; E-mail: amicosante{at}cc.univaq.it

Objectives: Kinetic characterization of TEM-134, a new TEM-type extended-spectrum ß-lactamase variant isolated from Citrobacter koseri during an Italian nationwide survey. TEM-134 is a natural derivative of TEM-2 with the following substitutions: E104K, R164H and G238S.

Methods: Recombinant TEM-134 was purified from Escherichia coli HB101 (pMGP-134) by three chromatographic steps (cation-exchange chromatography, gel permeation and fast chromatofocusing). Steady-state kinetic parameters (Km and kcat) were determined by measuring substrate hydrolysis under initial rate conditions using the Hanes linearization of the Michaelis–Menten equation. Modelling was carried out using the software Modeller (version 9.1).

Results: TEM-134 hydrolysed with variable efficiency (kcat/Km ranging from 5 x 103 to 8.0 x 105 M–1 · s–1) penicillins, narrow-spectrum cephalosporins, cefepime, cefotaxime, ceftazidime and aztreonam, which appeared to be the best substrate. Molecular modelling of the enzyme indicated that the R164H substitution may result in a compromised omega loop in TEM-134 and this may be responsible for its narrower spectrum of activity.

Conclusions: Kinetic data and molecular modelling suggested that R164H has a mild detrimental effect on the global activity of the enzyme.

Key Words: Enterobacteriaceae , antibiotic resistance , class A


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Antimicrob. Agents Chemother.Home page
C. H. Jones, A. Ruzin, M. Tuckman, M. A. Visalli, P. J. Petersen, and P. A. Bradford
Pyrosequencing Using the Single-Nucleotide Polymorphism Protocol for Rapid Determination of TEM- and SHV-Type Extended-Spectrum {beta}-Lactamases in Clinical Isolates and Identification of the Novel {beta}-Lactamase Genes blaSHV-48, blaSHV-105, and blaTEM-155
Antimicrob. Agents Chemother., March 1, 2009; 53(3): 977 - 986.
[Abstract] [Full Text] [PDF]

Home page
 Antimicrob. Agents Chemother.Home page
M. Perilli, G. Celenza, F. De Santis, C. Pellegrini, C. Forcella, G. M. Rossolini, S. Stefani, and G. Amicosante
E240V Substitution Increases Catalytic Efficiency toward Ceftazidime in a New Natural TEM-Type Extended-Spectrum {beta}-Lactamase, TEM-149, from Enterobacter aerogenes and Serratia marcescens Clinical Isolates
Antimicrob. Agents Chemother., March 1, 2008; 52(3): 915 - 919.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.