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.

Distribution of fibronectin-binding protein genes (prtF1 and prtF2) and streptococcal pyrogenic exotoxin genes (spe) among Streptococcus pyogenes in Japan

“…12 In the present study, the proportion of isolates carrying the prtF1 gene was higher among strains from noninvasive infections than among strains from invasive infections, although the prevalence of isolates with the prtF1 gene among strains from invasive infections varied between 50% and 65% in other studies. 3,6,8,10,[19][20][21] In contrast, the carriage rate of the prtF2 gene was comparable to the proportion generally reported in other studies. 10,[22][23][24] Isolates carrying the prtF1 and prtF2 genes simultaneously were more prevalent among strains from noninvasive infections than among strains from invasive infections.…”

Detection of Genes Encoding Internalization-Associated Proteins in Streptococcus pyogenes Isolates from Patients with Invasive Diseases and Asymptomatic Carriers

“…In particular, proteins of the series F have been demonstrated to have a role in the pathogenesis of group A streptococcal infections. The proportion of prtF1 gene reported in other studies varies greatly, ranging from more than 70 to 80% (11,25) to 30 to 40% (6,20,27). The only study examining strains from invasive infections (30) reported an extremely low incidence of prtF1 among isolates from invasive infections in Europe, limited to emm6 type isolates; however, we found that the forward primer they used was specific for emm6 and could not detect prtF1 sequences that differed in the specific segment in other emm types (data not shown).…”

Association between Resistance to Erythromycin and the Presence of the Fibronectin Binding Protein F1 Gene, prtF1 , in Streptococcus pyogenes Isolates from German Pediatric Patients

“…Macrolide resistance mechanisms include target site modification, leading to resistance to macrolides, lincosamides, and streptogramin B (MLS phenotype), or an efflux mechanism mediating resistance only to 14-and 15-membered macrolides (M phenotype) (11). Recently, an association between erythromycin resistance and cell invasiveness, as demonstrated by the presence of the fibronectin binding protein F1, encoded by the prtF1 gene, has been observed (8,14). In addition, Cocuzza et al recently demonstrated selection for prtF1-positive strains after ␤-lactam therapy (5).…”