Epidemiological and molecular characteristics of clinical isolates of Streptococcus pyogenes collected between 2005 and 2008 from Chinese children

Abstract

The aim of this study was to explore the epidemiological and molecular characteristics of Streptococcus pyogenes in children from different cities in mainland China who were diagnosed with scarlet fever, impetigo and pharyngitis, as well as to detect asymptomatic carriers, between 2005 and 2008, and to compare the results with isolates from rural Chinese children with acute glomerulonephritis in 2005 and in the 1990s. Susceptibility tests to determine MICs and analysis of the presence of erythromycin-resistant genes (mefA, ermB and ermA) and emm gene typing were performed on 466 S. pyogenes isolates from Beijing, Shanghai, Chongqing and Shenzhen. Superantigen genes (speA and speC) were examined by performing PCR on isolates with the most prevalent emm genotype. All isolates were sensitive to penicillin, cefradine and ofloxacin. The highest rate of resistance was against clarithromycin (98.1 %), followed by erythromycin (97.6 %), azithromycin and clindamycin (both 97.2 %), and tetracycline (94.0 %). Among the 466 isolates, 421 (90.3 %) harboured the ermB gene, 145 (31.1 %) were speA-positive and 273 (58.6 %) were speC-positive. The speA gene was common in emm1.0 (88.8 %) and emm6.5 (83.3 %) genotypes. The speC gene was frequently observed in emm4.0 (90.0 %), emm12.0 (69.6 %), emm18.0 (66.7 %), emm22.0 (75.9 %) and emm80.0 (80.0 %) genotypes. The most prevalent emm genotypes in mainland China in recent years were emm1.0 and emm12.0. All isolates remained sensitive to b-lactams and quinolone.

Prevalence of group A β-haemolytic Streptococcus among children with pharyngitis in Jimma town, Southwest Ethiopia

“…27 However, various levels of resistance to erythromycin and clindamycin were reported in Turkey, 16 Tunisia 28 and China. 29 In the present study, 52.5% GAS isolates were resistant to tetracycline which was comparable with 68% reported in Ethiopia 6 and 50% in Brazil, 27 but much lower than 70% and 94% resistance rates documented in Tunisia 28 and China 29 respectively.…”

Disease Manifestations and Pathogenic Mechanisms of Group A Streptococcus

“…Large-scale epidemiological studies have shown a remarkable difference in the distribution of emm types in geographically and socioeconomically distinct regions of the world (2-4, 31, 32, 42). In industrialized societies, a significant percentage of GAS isolates belong to a few emm types, most notably emm types 1, 3, 12, and 28, which account for approximately 40% of disease in these countries (4,(43)(44)(45)(46)(47). These types are also the types most commonly isolated from asymptomatic carriers (43).…”

Draft Genome Sequences of Two Streptococcus pyogenes Strains Involved in Abnormal Sharp Raised Scarlet Fever in China, 2011

“…The two strains were both cultured from throat swabs of scarlet fever patients who were under 12 years old. Molecular typing studies proved that the two strains both belonged to type emm12, which had been reported to be the predominant emm type in China in previous studies (2,(9)(10)(11).…”