Abstract | OBJECTIVES: METHODS: A S. aureus strain carrying an inducibly expressed erm(C) gene was incubated on agar plates containing inhibitory concentrations of each of the three antimicrobial agents. The erm(C) regulatory region of mutants obtained after overnight incubation was amplified by PCR; selected amplicons were sequenced and compared with the wild-type sequence. RESULTS: Mutants developed in the presence of each of the three antimicrobial agents. Constitutive expression of erm(C) was due to variations in the erm(C) regulatory region. A total of 10 different types of deletions ranging in size between 16 and 121 bp as well as 20 different types of duplications ranging between 24 and 602 bp were detected. The frequencies by which sequence alterations occurred as well as the types of alterations detected varied with regard to the antimicrobial agents used for selection. CONCLUSIONS: All sequence alterations observed explained constitutive erm(C) gene expression by functional inactivation of translational attenuation. In order to prevent the development of constitutively resistant isolates under therapy, the results of this study support the recommendation not to use lincosamides or 16-membered macrolides for the control of staphylococcal infections caused by strains harbouring inducibly expressed erm(C) genes.
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Authors | Petra Lüthje, Stefan Schwarz |
Journal | The Journal of antimicrobial chemotherapy
(J Antimicrob Chemother)
Vol. 59
Issue 1
Pg. 97-101
(Jan 2007)
ISSN: 0305-7453 [Print] England |
PMID | 17085767
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Anti-Bacterial Agents
- Clindamycin
- Spiramycin
- Methyltransferases
- rRNA (adenosine-O-2'-)methyltransferase
- pirlimycin
- Tylosin
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Topics |
- Animals
- Anti-Bacterial Agents
(pharmacology)
- Cattle
- Clindamycin
(analogs & derivatives, pharmacology)
- Genes, Bacterial
- Methyltransferases
(genetics)
- Microbial Sensitivity Tests
- Polymerase Chain Reaction
- Spiramycin
(pharmacology)
- Staphylococcus aureus
(drug effects, genetics)
- Tylosin
(pharmacology)
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