Molecular typing of β-haemolytic group A Streptococcus isolates in Jinan of Shandong, 2012–2018

ObjectiveTo analyze the emm genotypes of β-haemolytic group A Streptococcus (GAS) isolates in Jinan of Shandong province and provide data for etiologic surveillance for scarlet fever.

MethodsGAS isolates were collected in Jinan from 2012 to 2018. The emm gene was amplified by PCR and the emm genotypes were obtained after the PCR products were sequenced and aligned.

ResultsA total of 143 GAS strains were isoalted, belonging to 5 emm genotypes: emm12 (55.2%, 79/143), emm1 (42.0%, 60/143), and other three genotypes (2.8%, 4/143). Only 11 strains were isolated in 2015 and 2016, all belonged to emm12. Four emm genotypes were found in 116 isolates from patients, in which 97.4% were emm1 (46 strains) and emm12 (67 strains), and 2.6% were emm22 (1 strain) and emm75 (2 strains). The first 3 districts where the isolate numbers were high were Shizhong (85 strains), Huaiyin (35 starins) and Licheng (9 strains).

ConclusionThe main emm genotypes of GAS were emm12 and emm1 in Jinan from 2012 to 2018 and emm1 was predominant in 2013 and 2014, while emm12 was predominant in other years.