Background: Fluoroquinolone resistance is common in Staphylococcus aureus, is increasing in Streptococcus pneumoniae, and is reported in Streptococcus pyogenes.
Methods: We surveyed 384 clinical isolates of S. pyogenes, isolated during 2002-2003, for susceptibility to ciprofloxacin. We performed nucleotide sequencing of the parC and gyrA genes and determined the M/emm type for selected isolates. Additionally, we analyzed M/emm type 6 S. pyogenes isolated during 1918-2003 from diverse locations.
Results: Of the survey isolates, 10.9% had reduced zones of inhibition to ciprofloxacin in the disk-diffusion test and had elevated minimum inhibitory concentrations to other fluoroquinolones, compared with those of fully susceptible isolates. Of the resistant isolates, 90.5% were M/emm type 6, and all sequenced M/emm type 6 isolates contained a serine-to-alanine substitution at position 79 in parC. Strikingly, the same findings were also present in macrolide-resistant isolates from a recent outbreak of S. pyogenes infection in Pittsburgh and in the Lancefield reference strain of M type 6, which was isolated in 1918, decades before the development of fluoroquinolone antibiotics.
Conclusion: M/emm type 6 S. pyogenes has intrinsic reduced susceptibility to fluoroquinolones, as a result of a polymorphism in parC. This finding was also demonstrated in erythromycin-resistant M/emm type 6 S. pyogenes, which raises concern for the emergence of multidrug-resistant S. pyogenes.
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http://dx.doi.org/10.1086/428856 | DOI Listing |
Vaccine
September 2023
Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, United States; UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, TN 37830, United States.
The M protein of group A streptococci (Strep A) is a major virulence determinant and protective antigen. The N-terminal region of the M protein is variable in sequence, defines the M/emm type, and contains epitopes that elicit opsonic antibodies that protect animals from challenge infections. Although there are >200 M types of Strep A, there is now evidence that structurally related M proteins can be grouped into clusters and that immunity may be cluster-specific in addition to M type-specific.
View Article and Find Full Text PDFJ Med Microbiol
December 2014
Maurice Wilkins Centre, University of Auckland, Auckland, New Zealand.
Group A streptococcus (GAS) is responsible for a wide range of diseases ranging from superficial infections, such as pharyngitis and impetigo, to life-threatening diseases, such as toxic shock syndrome and acute rheumatic fever (ARF). GAS pili are hair-like extensions protruding from the cell surface and consist of highly immunogenic structural proteins: the backbone pilin (BP) and one or two accessory pilins (AP1 and AP2). The protease-resistant BP builds the pilus shaft and has been recognized as the T-antigen, which forms the basis of a major serological typing scheme that is often used as a supplement to M typing.
View Article and Find Full Text PDFClin Infect Dis
December 2010
National Centre for Streptococcus and The Provincial, Laboratory for Public Health Microbiology, Division of Medical Microbiology, Department of Laboratory Medicine and Pathology, Edmonton, Alberta, Canada.
Background: The incidence of invasive group A Streptococcus (GAS) disease can vary over time and geographic region, possibly reflecting the population's susceptibility to particular strains but also variation in the predominant M/emm types. Canadian surveillance documented an epidemic of an uncommon M/emm59 type from 2006 to 2009.
Methods: Invasive GAS isolates are submitted by Public Health Laboratories in Canada to the National Centre for Streptococcus for M/emm typing.
J Clin Microbiol
April 2009
Department of Clinical Microbiology and Immunology, Lund University Hospital (USIL), Lund, Sweden.
In an attempt to compare the epidemiology of severe Streptococcus pyogenes infection within Europe, prospective data were collected through the Strep-EURO program. Surveillance for severe cases of S. pyogenes infection diagnosed during 2003 and 2004 was undertaken in 11 countries across Europe by using a standardized case definition and questionnaire.
View Article and Find Full Text PDFDiagn Microbiol Infect Dis
October 2008
Food and Drug Administration, DHHS, Rockville, MD 20855, USA.
A total of 116 clinical isolates collected in 2003 from a tertiary pediatric hospital and a primary pediatric department in Chicago, IL, were screened for reduced susceptibility to selected fluoroquinolones by disc diffusion. Correlation between reduced susceptibility and point mutations in the quinolone resistance-determining region of parC and gyrA genes was evaluated, and point mutations were compared with other reports of isolates derived from adult or mixed patient populations. Nine percent of isolates had reduced susceptibility to 1 or more of these fluoroquinolones by Etest: ciprofloxacin, levofloxacin, and moxifloxacin.
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