title: emm Gene distribution among erythromycin-resistant and -susceptible Italian isolates of Streptococcus pyogenes.
abstract: The phenotypes and genetic determinants for macrolide resistance were determined for 167 erythromycin-resistant Streptococcus pyogenes strains. A cMLS phenotype was shown in 18% of the erythromycin-resistant strains, while inducible resistance was apparent in 31% and the M phenotype was apparent in 50%. The emm gene type of this set of resistant isolates and that of 48 erythromycin-sensitive isolates were determined. emm2 and emm48 were recorded only in the resistant strains of the M phenotype, while approximately all of the strains harboring the emm22 gene had the cMLS phenotype. More than 80% of the emm89-positive strains had the iMLS phenotype, and the same portion of emm4 strains presented the M phenotype. emm3 is recorded only among sensitive strains. The distribution of frequencies of the genetic determinant for the virulence factor M protein was significantly different both among organisms of different types of resistance and between resistant and sensitive populations of S. pyogenes under study.
authors.affiliation: Department of Molecular Cellular Animal Biology, University of Camerino, 62032 Camerino, Italy. sandro.ripa@unicam.it
authors.forename: Claudia
authors.initials: C
authors.lastname: Zampaloni
authors.forename: Paola
authors.initials: P
authors.lastname: Cappelletti
authors.forename: Manuela
authors.initials: M
authors.lastname: Prenna
authors.forename: Luca Agostino
authors.initials: LA
authors.lastname: Vitali
authors.forename: Sandro
authors.initials: S
authors.lastname: Ripa
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004917:Erythromycin / Q000494:pharmacology*; D005787:Gene Frequency; D006801:Humans; D007558:Italy; D008565:Membrane Proteins / Q000235:genetics; D008826:Microbial Sensitivity Tests; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; C099983:Emm2 protein, Streptococcus pyogenes; C087175:Emm22 protein,Streptococcus pyogenes; D008565:Membrane Proteins; D004917:Erythromycin