Characterization of Group C and G Streptococcal Strains That Cause Streptococcal Toxic Shock Syndrome

Abstract

Twelve strains (the largest number ever reported) of group C and G 1 streptococci (GCS and GGS, respectively) that caused streptococcal toxic shock syndrome (STSS) were collected and characterized. Eleven strains were identified as Streptococcus dysgalactiae subsp. equisimilis, and one strain was identified as Streptococcus equi subsp. zooepidemicus. We found that it was the first reported case of STSS caused by S. equi subsp. zooepidemicus. Cluster analysis according to the 16S rRNA gene (rDNA) sequences revealed that the S. dysgalactiae strains belonged to clusters I and II, both of which were closely related. The emm types and the restriction patterns of chromosomal DNA measured by pulsed-field gel electrophoresis were highly variable in these strains except BL2719 and N1434. The 16S rDNA sequences and other characteristics of these two strains were indistinguishable, suggesting the clonal dissemination of this particular S. dysgalactiae strain in Japan. As the involvement of superantigens in the pathogenesis of group A streptococcus-related STSS has been suggested, we tried to detect known streptococcal superantigens in GCS and GGS strains. However, only the spegg gene was detected in seven S. dysgalactiae strains, with none of the other superantigen genes being detected in any of the strains. However, the sagA gene was detected in all of the strains except Tokyo1291. In the present study no apparent factor(s) responsible for the pathogenesis of STSS was identified, although close genetic relationships of GCS and GGS strains involved in this disease were suggested.

Molecular emm genotyping and antibiotic susceptibility of Streptococcus dysgalactiae subsp. equisimilis isolated from invasive and non-invasive infections

“…equisimilis strains having group A antigen rather than group C or G antigen have also been reported (Bert & Lambert-Zechovsky, 1997;Brandt et al, 1999;Katsukawa et al, 2002). Many recent studies have reported that this organism causes invasive and systemic streptococcal infections like GAS (Natoli et al, 1996;Wagner et al, 1996; Hirose et al, 1997; Kugi et al, 1998;Barnham et al, 2002;Cohen-Poradosu et al, 2004;Hashikawa et al, 2004). The organism has also been reported to cause a wide variety of human infections such as pharyngitis, cellulitis, sepsis, meningitis and endocarditis (Woo et al, 2001).…”

Antistreptolysin O (ASO) titers and beta-haemolytic streptococcus (BHS) in Children in Calabar, Nigeria.

“…Group C and G Streptococci are reportedly common causes of tonsillitis or pharyngitis in both adults and children in tropical countries [8,9,11] while group A is common in the temperate countries [29]. Other streptococcal groups of D, F and G isolated in this study have previously been implicated in tonsillitis [30].…”

“…The beta haemolytic streptococci group C and G have also been reported as causing acute pharyngitis but their involvement in RF and RHD is still controversial [7,8,9,10]. GAS infection is spread by droplets, thus accounting for it high transmissibility in such situations [11].…”

Soft tissue infection caused by Streptococcus dysgalactiae subsp. equisimilis possessing group Aantigen: a and review of the literature

“…However, some strains are found to induce α-hemolysis or no hemolysis at all, in the abovedescribed standard conditions [20][21][22]. As in the case of S. pyogenes, there exist strains of SDSE which produce oxygen-labile streptolysin O, and no streptolysin S [20,23,24]. The occurrence of such strains has been an incentive to search for media and conditions of incubation which would enhance the activity of streptolysin O [20].…”

“…Both species have antiphagocytic M protein, encoded by emm [10,35,36] and hyaluronic capsule [10,35]. There are, however, marked differences between them: SDSE, for example, lacks the whole set of genes encoding superantigens, which are mostly of phage origin (spe A, spe B, spe C, spe H, spe I, spe J, spe K, spe L, spe M, ssa, smez) [12,15,24,35,[38][39][40][41][42]. However, scarce occurrences of SDSE strains have been described, having one of those genes [32,43].…”