back to 2006, vol. 12, b. 1
Journal of IMAB - Annual Proceeding (Scientific Papers)
Publisher: Peytchinski, Gospodin Iliev
ISSN: 1312 773X (Online)
Issue: 2006, vol. 12, issue 1
Subject Collection: Medicine
Page: 11-15
DOI: 10.5272/jimab.2006121.11
Online date: November 4, 2006

J of IMAB 2006; 12(1):11-15
CHARACTERISTICS OF ERYTHROMYCIN-RESISTANT CLINICAL ISOLATES OF STREPTOCOCCUS PYOGENES.
Antoaneta Decheva1, V. Karjeva1, D. Beshkov1, I. Alexiev1, Simona Bianco2, Daniela Savoia2
1) National Center of Infectious and Parasitic Diseases, Sofia, Bulgaria.
2) Department of Clinical and Biological Sciences, University of Torino, Italy
.

ABSTRACT:
Erythromycin resistance of clinical isolates Streptococcus pyogenes recovered in Bulgaria during 1995-2005 was studied by phenotypic and genetic methods. The frequency of erythromycin resistance was low during the whole period tested (0.5 to 4.1%). Fifty percent of the resistant isolates belonged to the MLS-inducible resistance phenotype, 38.9% were from the M phenotype and 11.1% were from the MLS-constitutive resistance phenotype. Two thirds (63.9%) of the erythromycin-resistant isolates were additionally resistant to tetracycline and / or chloramphenicol. Our data suggest that the resistance itself is not associated with increased pathogenicity of the clinical isolates S. pyogenes. The statistical analysis revealed that there was no difference between resistant and susceptible isolates regarding the following factors tested: production of protease, possession of speA (encoding streptococcal pyrogenic exotoxin A), speF(encoding streptococcal pyrogenic exotoxin F) and prtF1 (encoding protein F1). The MLS-inducibly resistant isolates were more frequently serum-opacity factor positive (81.3%) than susceptible isolates (32.4%) (p<0.05). Emm sequence typing revealed that the erythromycin resistant isolates were a heterogenous group. Overlapping of sequence types between isolates of different resistance phenotypes was very rare. For isolates with the target site modification mechanism of resistance, emm 44/61 was the most frequent sequence type. For isolates with efflux mechanism, emm 12.10 was the most common one. The group of erythromycin-susceptible isolates was also heterogenous as a whole with emm 1, emm 3 and emm 12 being most common types. Overlapping of sequence types between susceptible and resistant isolates was observed for emm 1, emm 12, emm 75 and emm 77.

Key words: Erythromycin resistance, Streptococcus pyogenes.

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Please cite this article as:
Decheva A, Karjeva V, Beshkov D, Alexiev I, Bianco S, Savoia D. CHARACTERISTICS OF ERYTHROMYCIN-RESISTANT CLINICAL ISOLATES OF STREPTOCOCCUS PYOGENES. J of IMAB. 2006; 12(1):11-15; DOI:10.5272/jimab.2006121.11

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