Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2000 Nov;44(11):3196-8.
doi: 10.1128/AAC.44.11.3196-3198.2000.

Resistance to multiple fluoroquinolones in a clinical isolate of Streptococcus pyogenes: identification of gyrA and parC and specification of point mutations associated with resistance

S S Yan  1 , M L Fox, S M Holland, F Stock, V J Gill, D P Fedorko
Affiliations

Resistance to multiple fluoroquinolones in a clinical isolate of Streptococcus pyogenes: identification of gyrA and parC and specification of point mutations associated with resistance

S S Yan et al. Antimicrob Agents Chemother. 2000 Nov.

Abstract

A strain of Streptococcus pyogenes resistant to multiple fluoroquinolones was isolated from the blood of an immunocompromised patient. Resistance to fluoroquinolones in S. pyogenes has not been previously studied. Compared to 10 sensitive strains of S. pyogenes, the fluoroquinolone-resistant clinical isolate of S. pyogenes presented point mutations in gyrA, predicting that serine-81 was changed to phenylalanine and that methionine-99 was changed to leucine, and in parC, predicting that serine-79 was changed to tyrosine. The mechanism of fluoroquinolone resistance in this isolate of S. pyogenes appears to be analogous to previously reported mechanisms for Streptococcus pneumoniae.

PubMed Disclaimer

Figures

FIG. 1
FIG. 1
Protein tree for the full-length gyrase A and ParC subunit of topoisomerase IV of several bacterial species. The protein sequences are from GenBank. The phylogenetic distance was determined using the unbalanced method provided by the computer program MegAlign. Lengths of branches correspond to sequence divergence. The scale underneath the tree represents the actual number of amino acid substitutions.
See this image and copyright information in PMC

References

    1. Balas D, Fernandez-Moreira E, De La Campa A G. Molecular characterization of the gene encoding the DNA gyrase A subunit of Streptococcus pneumoniae. J Bacteriol. 1998;180:2854–2861. - PMC - PubMed
    1. Blondeau J M. A review of the comparative in-vitro activities of 12 antimicrobial agents, with a focus on five new respiratory quinolones. J Antimicrob Chemother. 1999;43(Suppl. B):1–11. - PubMed
    1. Chen D K, McGeer A, de Azavedo J C, Low E E the Canadian Bacterial Surveillance Network. Decreased susceptibility of Streptococcus pneumoniae to fluoroquinolones in Canada. Canadian Bacterial Surveillance Network. N Engl J Med. 1999;341:233–239. - PubMed
    1. Drlica K. Mechanism of fluoroquinolone action. Curr Opin Microbiol. 1999;2:504–508. - PubMed
    1. Ferraro M J, Craig W A, Dudley M N, Eliopoulos G, Hecht D W, Hindler J, Reller L B, Sheldon A T, Swenson J M, Tenover F C, Testa R T, Weinstein M P, Wikler M A. NCCLS (ed.), Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically. Approved standard, 5th ed. M7-A5 and M100-S10. Wayne, Pa: NCCLS; 2000.

Associated data

LinkOut - more resources