Erythromycin resistance in italian isolates of Streptococcus pyogenes and correlations with pulsed-field gel electrophoresis analysis.
Erythromycin resistance among Streptococcus pyogenes strains has been reported in Italy at high rates during the last few years. A total of 152 erythromycin-resistant isolates of this species from southern Italian regions were characterized for the macrolide-resistance phenotype and screened by PCR for the corresponding genetic determinant. A close correlation was found between these phenotypic/genotypic data concerning macrolide resistance and results of Sma I macrorestriction fragment patterns (PFGE) analysis. In fact, the vast majority of the isolates assigned to individual PFGE classes mostly belonged to a single phenotype of macrolide resistance. All untypeable isolates belonged to the M phenotype. Twenty-two distinct PFGE types were recognized, of which 11 were recorded in only one isolate (one-strain type); about 50% of typeable isolates fell into five type clusters and 70% in seven. The increased erythromycin resistance among Italian isolates of S. pyogenes does not appear to be due to the spread of a single clone, but results indicate that the majority of group A streptococci examined are probably spread from a limited number of clones.
Zampaloni
Claudia
C
Department of MCA Biology, University of Camerino, Italy.
Vitali
Luca A
LA
Prenna
Manuela
M
Toscano
Maria A
MA
Tempera
Gianna
G
Ripa
Sandro
S
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016521:Electrophoresis, Gel, Pulsed-Field; D004917:Erythromycin / Q000494:pharmacology*; D005798:Genes, Bacterial; D006801:Humans; D007558:Italy; D010614:Pharynx / Q000382:microbiology; D010641:Phenotype; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013290:Streptococcal Infections / Q000188:drug therapy* / Q000235:genetics / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000235:genetics
D000900:Anti-Bacterial Agents; D004917:Erythromycin