Epidemiological analysis of Group AStreptococcusinfections in a hospital in Beijing, China

摘要

Our study aimed to investigate the epidemiological and molecular characteristics of isolates collected from Group AStreptococcus(GAS) infections in children in Beijing China during the year 2019.Emmtyping, superantigens, and erythromycin resistance genotypes were determined by PCR. Antimicrobial susceptibility testing was performed as recommended by Clinical Laboratory Standards Institute (CLSI). A total of 271 GAS isolates were collected. Thirteen differentemmtypes, including 31 subtypes, were identified. The most prevalentemmtypes wereemm12(52.77%),emm1(36.9%),emm3.1(2.95%), andemm75.0(2.95%). Two variant subtypes,STC36.0andSTG840.2, were identified. There was no difference in the portion ofemm12andemm1isolates in scarlet fever, impetigo, and psoriasis. The majority of superantigens detected weresmeZ(94.46%),speC(91.14%), andssa(74.91%), followed byspeH(56.46%),speI(45.76%),speJ(36.9%), andspeA(34.32%). More scarlet fever isolates harboredspeA(35.6%) andspeJ(38.4%), more psoriasis isolates harboredspeI(57.9%), and more impetigo isolates harboredssa(89.7%). Isolates were universally susceptible to penicillin and resistant to erythromycin (94.83%). Moreover, 89.67% erythromycin resistance isolates harbored theermBgene.The erythromycin resistance rate of the isolates from the three diseases was different. Scarlet fever is the common streptococcal infectious disease in dermatology.Emm12andemm1were the most prevalentemmtypes. The most prevalent superantigens detected weresmeZ,spec, andssa. There is association between diversity of superantigens and disease manifestation. Hence, continuous surveillance of GAS molecular epidemiological characterizations in different diseases is needed.