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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
Macrolide resistance in group A streptococci
D Savoia1, C Avanzini, K Bosio
1Department of Clinical and Biological Sciences, University of Torino. Laboratory, Agnelli Hospital, Pinerolo (Torino) Laboratory, Paediatric Hospital, Torino, Italy. savoia@pasteur.sluigi.unito.it
The Journal of Antimicrobial Chemotherapy
|January 11, 2000
Summary
High rates of erythromycin resistance in Streptococcus pyogenes pharyngotonsillitis were observed in Italy. Genetic analysis revealed diverse genomic profiles, indicating resistance isn't due to a single clone or serotype.
Area of Science:
- Microbiology
- Genetics
- Infectious Diseases
Background:
- Streptococcus pyogenes causes pharyngotonsillitis in children.
- Macrolide resistance in S. pyogenes is a growing public health concern.
- Understanding resistance mechanisms is crucial for effective treatment.
Purpose of the Study:
- To evaluate macrolide resistance phenotypes in S. pyogenes isolates from children with pharyngotonsillitis.
- To investigate the genotypic characteristics of resistant strains.
- To determine if resistance is linked to specific T serotypes or clonal spread.
Main Methods:
- Phenotypic testing for macrolide resistance (erythromycin).
- T protein typing and assays for opacity factor (OF) and protease production.
- Pulsed-field gel electrophoresis (PFGE) for genomic profiling of resistant and susceptible strains.
Main Results:
- High prevalence of erythromycin resistance (43.5-51.2%) observed in both study centers.
- Three resistance phenotypes identified: constitutive (CR), inducible (IR), and a novel phenotype (NR).
- PFGE revealed five distinct genomic profiles among resistant strains, with NR strains showing three patterns.
Conclusions:
- S. pyogenes strains exhibit significant genetic heterogeneity.
- The high rate of erythromycin resistance is not attributed to the spread of a single clone.
- Resistance phenotype is related to genomic patterns, with limited association with T serotype.
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