title: Internalization-associated proteins among Streptococcus pyogenes isolated from asymptomatic carriers and children with pharyngitis.
abstract: Sixty-two strains of Streptococcus pyogenes isolated from 30 asymptomatic school children and 32 children with pharyngitis were characterized to analyze the involvement of 2 fibronectin-binding proteins (F/SfbI and PrtF2/PfbpI) in S. pyogenes colonizing asymptomatic carriers and to determine the possible association between these proteins and the genes associated with macrolide resistance. In this study, we demonstrated that the proportion of S. pyogenes strains carrying the pfbpI gene was significantly higher among asymptomatic carriers (80%) than among children with pharyngitis (53%; P<.05). With regard to the proportion of prtF1-positive strains, no significant differences were found between the 2 groups (70% vs. 69%, for asymptomatic carriers and children with pharyngitis, respectively). Another important finding is the significant association between macrolide resistance and protein F/SfbI (P<.001) in both groups. These results suggest that the presence of the pfbpI gene can be linked to the ability of S. pyogenes to persist in the throat of asymptomatic carriers.
authors.affiliation: Department of Microbiological and Gynecological Sciences, Section of Microbiology, University of Catania, 95124 Catania, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Musumeci
authors.forename: C Lo
authors.initials: CL
authors.lastname: Bue
authors.forename: I
authors.initials: I
authors.lastname: Milazzo
authors.forename: G
authors.initials: G
authors.lastname: Nicoletti
authors.forename: A
authors.initials: A
authors.lastname: Serra
authors.forename: A
authors.initials: A
authors.lastname: Speciale
authors.forename: G
authors.initials: G
authors.lastname: Blandino
mesh_terms: D018829:Adhesins, Bacterial / Q000032:analysis / Q000235:genetics; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D002353:Carrier State; D002648:Child; D004351:Drug Resistance / Q000235:genetics; D004917:Erythromycin / Q000494:pharmacology; D006801:Humans; D010612:Pharyngitis / Q000382:microbiology*; D013290:Streptococcal Infections / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D018829:Adhesins, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; C078635:fibronectin-binding proteins, bacterial; D004917:Erythromycin