title: A practical method for subtyping of Streptococcus agalactiae serotype III, of human origin, using rolling circle amplification.
abstract: Group B streptococcus (GBS; Streptococcus agalactiae) serotype III is one of the most common and virulent serotypes of the species. It can be divided into several subtypes, which vary in their distribution among invasive isolates from different patient groups. In this study, we used 91 well-characterized GBS serotype III isolates to compare three subtyping methods, and developed a novel padlock probe and rolling circle amplification (RCA) method to identify informative single nucleotide polymorphisms (SNPs) that define the major subtypes. There was good agreement between partial sequencing of the capsule polysaccharide synthesis (cps) gene cluster, a 3-set genotyping system and multilocus sequence typing (MLST). Serosubtype III-2/multilocus sequence type (ST)-17 represents a virulent clone which is significantly associated with late onset GBS neonatal infections. RCA provides a simple, reproducible method for rapid identification of the two most common GBS serotype III subtypes (III-1/ST-19 and III-2/ST-17).
authors.affiliation: Centre for Infectious Diseases and Microbiology-Public Health, Institute of Clinical Pathology and Medical Research, Westmead Hospital, Darcy Road, Westmead, New South Wales, 2145 Australia.
authors.forename: Zhongsheng
authors.initials: Z
authors.lastname: Tong
authors.forename: Fannrong
authors.initials: F
authors.lastname: Kong
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Xianyu
authors.initials: X
authors.lastname: Zeng
authors.forename: Gwendolyn L
authors.initials: GL
authors.lastname: Gilbert
mesh_terms: D000328:Adult; D016667:Bacterial Capsules / Q000235:genetics; D015373:Bacterial Typing Techniques / Q000379:methods*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D015203:Reproducibility of Results; D017422:Sequence Analysis, DNA; D013290:Streptococcal Infections / Q000382:microbiology*; D013292:Streptococcus agalactiae / Q000145:classification*
chemical_list: D004269:DNA, Bacterial