Drug Susceptibility and Analysis Using Pulsed-Field Gel Electrophoresis of Streptococcus pyogenes Strains Isolated from the Patients with Streptococcal Toxic Shock Syndrome (STSS) in Japan

Previously, we have performed T typing of Streptococcus pyogenes strains isolated from patients with streptococcal toxic shock syndrome (STSS) in Japan, and streptococcal pyrogenic exotoxin (SPE) typing for epidemiological examination. In this study, we conducted a drug sensitivity test using these strains, and investigated the results of gene analysis by pulse-field gel electrophoresis (PFGE) of S. pyogenes strains derived from patients with STSS, the patient's family, and patients other than those with STSS. To clarify the relationship between the host and bacterial factors, we investigated the association between clinical symptoms and T typing of the isolated strains/production of streptococcal pyrogenic exotoxin. There were no strains resistant to β-lactams, and only 1 strain was resistant to multiple agents other than β-lactams. The PFGE pattern of T1 type strains was classified into 2; the pattern was consistent between the strains derived from patients with STSS and those derived from the patient's family. The PFGE pattern of T3 type strains was classified into 5 (IV); Pattern I, which was most frequently observed, was detected in both the strains derived from patients with STSS/non-STSS. However, Patterns II and III were detected only in the strains derived from patients with non-STSS.Patterns IV and V were detected only in the strains derived from patients with STSS. When examining the association between clinical symptoms and bacterial factors, disseminated intravascular coagulation (DIC) was associated with Tl-SPE B-producing strains, and pharyngitis was associated with T3-SPE A-producing strains. In the future, the relationship between the host and bacterial factors should be further investigated.