Skip Navigation

This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
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 ISI Web of Science
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 arrow Search for citing articles in:
ISI Web of Science (9)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Kaneko, A.
Right arrow Articles by Kobayashi, I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kaneko, A.
Right arrow Articles by Kobayashi, I.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Journal of Antimicrobial Chemotherapy (2000) 45, 771-775
© 2000 The British Society for Antimicrobial Chemotherapy

Comparison of gyrA and parC mutations and resistance levels among fluoroquinolone-resistant isolates and laboratory-derived mutants of oral streptococci

Akihiro Kanekoa,*, Jiro Sasakia, Mitsunobu Shimadzub, Akiko Kanayamac, Takeshi Saikac and Intetsu Kobayashic

a Department of Oral Surgery, School of Medicine, Tokai University, Bouseidai, Isehara, Kanagawa, 259-1193 Japan; b Department of Genetics, and c Chemotherapy Division, Mitsubishi Kagaku Bio-Clinical Laboratories Inc., 3-30-1 Shimura, Itabashi-ku, Tokyo, 174-8555 Japan

Laboratory-derived fluoroquinolone-resistant mutants were obtained by serial passage of Streptococcus sanguis and Streptococcus anginosus isolates on agar containing increasing concentrations of old and new fluoroquinolones, ofloxacin and DU-6859a, respectively. Sequencing of an S. sanguis isolate exposed to DU-6859a showed that resistance was associated with two mutations in the quinolone resistance determining region (QRDR) of the gyrA gene (Ser83->Phe; Glu87->Lys), and with a mutation in the parC gene (Ser79->Ile). However, different mutations in the gyrA gene (Ser83->Tyr) and parC gene (Ser79->Phe) were found in a S. sanguis isolate exposed to ofloxacin. A fluoroquinolone-resistant isolate, QR-95101, from a dental infection, had a single mutation in the gyrA gene (Ser83->Phe) and in the parC gene (Ser79->Phe). Two fluoroquinolone-resistant mutants, QS-701OFm and QS-701DUm, were obtained from S. anginosus QS-701, by exposure to ofloxacin and DU-6859a, respectively. These mutants showed a common substitution at codon 83 (Ser->Phe) in the gyrA gene but had different substitutions at codon 87 (QS-701OFm, Glu->Gln; QS-701DUm, Glu->Lys). They also had different substitutions at codons 79 and 135 in the parC gene (QS-701OFm, Ser79->Leu but no change at Glu135; QS-701DUm, Ser79->Ile and Glu135->Gln). The resistance levels of the DU-6859a-selected resistant S. sanguis mutant QS-951DUm to DU-6859a, ofloxacin, ciprofloxacin and norfloxacin were higher than those of the ofloxacin-selected resistant mutant QS-951OFm. However, ampicillin susceptibilities of these mutants were not different from the parental strains. In S. anginosus, the DU-6859a-selected fluoroquinolone-resistant mutant QS-701DUm was resistant to all the fluoroquinolones tested, while the ofloxacin-selected mutant QS-701OFm was resistant to three fluoroquinolones, but not DU-6859a. The results indicate that different fluoroquinolones select distinct mutations in the QRDR of the gyrA and parC genes in oral streptococci. The gyrA or parC mutation in oral streptococci may determine the levels of fluoroquinolone resistance.

* Corresponding author. Tel: +81-463-93-1121; Fax: +81-463-91-5902; E-mail: akihiro{at}is.icc.u-tokai.ac.jp


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
K. Kosowska-Shick, K. Smith, T. Bogdanovich, L. M. Ednie, R. N. Jones, and P. C. Appelbaum
Activity of DX-619 Compared to Other Agents against Viridans Group Streptococci, Streptococcus bovis, and Cardiobacterium hominis
Antimicrob. Agents Chemother., December 1, 2006; 50(12): 4191 - 4194.
[Abstract] [Full Text] [PDF]

Home page
 Antimicrob. Agents Chemother.Home page
T. R. Shultz, P. A. White, and J. W. Tapsall
In Vitro Assessment of the Further Potential for Development of Fluoroquinolone Resistance in Neisseria meningitidis
Antimicrob. Agents Chemother., May 1, 2005; 49(5): 1753 - 1760.
[Abstract] [Full Text] [PDF]

Home page
 JCOHome page
M. Cruciani, M. Malena, O. Bosco, S. Nardi, G. Serpelloni, and C. Mengoli
Reappraisal With Meta-Analysis of the Addition of Gram-Positive Prophylaxis to Fluoroquinolone in Neutropenic Patients
J. Clin. Oncol., November 15, 2003; 21(22): 4127 - 4137.
[Abstract] [Full Text] [PDF]

Home page
 J. Clin. Microbiol.Home page
J. J. Millichap, E. Pestova, F. Siddiqui, G. A. Noskin, and L. R. Peterson
Fluoroquinolone Resistance Is a Poor Surrogate Marker for Type II Topoisomerase Mutations in Clinical Isolates of Streptococcus pneumoniae
J. Clin. Microbiol., July 1, 2001; 39(7): 2719 - 2721.
[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.