title: emm Types, virulence factors, and antibiotic resistance of invasive Streptococcus pyogenes isolates from Italy: What has changed in 11 years?
abstract: To investigate the epidemiology and characteristics of invasive group A streptococcal (GAS) disease over 11 years in Italy, this study compared the emm types and the superantigen toxin genes speA and speC as well as the erythromycin, clindamycin, and tetracycline susceptibilities of 207 invasive GAS strains collected during two national enhanced surveillance periods (1994 to 1996 and 2003 to 2005) and the time between each set of surveillance periods. The present study demonstrated that emm1 strains were consistently responsible for about 20% of invasive GAS infections, while variations in the frequencies of the other types were noted, although the causes of most cases of invasive infections were restricted to emm1, emm3, emm4, emm6, emm12, and emm18. During the 1994 to 1996 surveillance period, an emm89 epidemic clone spread across the northern part of Italy. A restricted macrolide resistance phenotype-type distribution of the bacteriophage-encoded speA toxin as well as of macrolide resistance genes was noted over time. Indeed, the recent acquisition of macrolide resistance in previously susceptible emm types was observed.
authors.affiliation: Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy. roberta.creti@iss.it
authors.forename: Roberta
authors.initials: R
authors.lastname: Creti
authors.forename: Monica
authors.initials: M
authors.lastname: Imperi
authors.forename: Lucilla
authors.initials: L
authors.lastname: Baldassarri
authors.forename: Marco
authors.initials: M
authors.lastname: Pataracchia
authors.forename: Simona
authors.initials: S
authors.lastname: Recchia
authors.forename: Giovanna
authors.initials: G
authors.lastname: Alfarone
authors.forename: Graziella
authors.initials: G
authors.lastname: Orefici
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D024901:Drug Resistance, Multiple, Bacterial; D005098:Exotoxins / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000235:genetics* / Q000378:metabolism; D013997:Time Factors; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D005098:Exotoxins; D037521:Virulence Factors; C027951:erythrogenic toxin; C014689:streptococcal M protein