title: Molecular characterization of group G Streptococcus dysgalactiae subsp. equisimilis recovered from patients and healthy people in China.
abstract: Beta-Hemolytic group G streptococci cause a considerable invasive disease burden and sometimes disease outbreaks. Little is known about the critical epidemiologic parameter of genetic relatedness between isolates. We determined the emm types of 65 Streptococcus dysgalactiae subsp. equisimilis isolates. We formulated multilocus sequence typing (MLST) primers with 6 of the 7 loci corresponding to the Streptococcus pyogenes MLST scheme. We performed MLST with 69 S. dysgalactiae subsp. equisimilis isolates to represent each emm type identified. These strains were further analyzed by pulsed-field gel electrophoresis (PFGE) typing. Sixteen emm types were observed. Eighteen unique combinations of allelic profiles (sequence types [STs]) were obtained with 12 profiles each accounting for multiple isolates. Forty-one MLST STs were observed. Analysis of the PFGE patterns generated revealed 10 clones. Over 80% of the isolates were distributed in 3 large clones. Isolates within 16 redundantly represented S. dysgalactiae subsp. equisimilis emm types shared identical or nearly identical STs and subtypes of PFGE, demonstrating concordance between the emm type and genetic relatedness. It is conceivable that some particular characteristics in the genomes of these strains are responsible for their predominance in different regions.
authors.affiliation: Key Laboratory of Major Diseases, Capital Medical University, Ministry of Education, Beijing Pediatric Research Institute, Beijing Children's Hospital Affiliated to Capital Medical University, Beijing, 100045, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yin
authors.forename: Sangjie
authors.initials: S
authors.lastname: Yu
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.forename: Lin
authors.initials: L
authors.lastname: Zhou
authors.forename: Lili
authors.initials: L
authors.lastname: Ji
authors.forename: Xuzhuang
authors.initials: X
authors.lastname: Shen
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Yang
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002353:Carrier State / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D002681:China; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D013290:Streptococcal Infections / Q000382:microbiology*; D013291:Streptococcus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; C014689:streptococcal M protein