title: Molecular diagnostics and ITS-based phylogenic analysis of Streptococcus suis serotype 2 in central Vietnam.
abstract: BACKGROUND
  Streptococcus suis (S. suis) serotype 2 has recently become the most prevalent cause of meningitis in adults in many areas of Vietnam. This study provides data on S. suis molecular diagnosis in central Vietnam using a real-time polymerase chain reaction (PCR) assay targeting the S. suis serotype 2 cps2J gene. Additionally, 16S-23S rDNA intragenic spacer (ITS)-based phylogenic analysis of strains isolated from cerebrospinal fluid (CSF) in Thua Thien Hue Province, Vietnam, is presented and discussed.
  
  
  METHODS
  Pathogenic bacteria were isolated from 40 CSF samples, and 18 were identified as S. suis by culture-dependent methods. Capsular serotyping was assessed by real-time PCR. ITS sequences were obtained after traditional PCR and were used in phylogenic analyses.
  
  
  RESULTS
  Pathogenic bacteria were isolated from 36 out of 40 CSF samples. A total of 18 S. suis strains were isolated and assigned to serotype 2 by real-time PCR. One CSF sample, negative when tested by culture-dependent methods, was positive to S. suis serotype 2 by real-time PCR. Pairwise alignments of the 18 ITS sequences did not reveal any variable nucleotide position, and resulted in a single sequence type. Sequences were similar to S. suis serotype 2 reference ITS sequences (> 98.1%), and there was no lack of an ITS spacer region in the isolates.
  
  
  CONCLUSIONS
  S. suis serotype 2 is the most prevalent serotype in central Vietnam. Real-time PCR assay proved to be a reliable diagnostic method for early detection of S. suis 2 in CSF samples.
authors.affiliation: Hue University of Medicine and Pharmacy,University of Hue, Hue, Vietnam. nhbach@huemed-univ.edu.vn.
authors.forename: Bach Hoang
authors.initials: BH
authors.lastname: Nguyen
authors.forename: Dieu Hong Nu
authors.initials: DH
authors.lastname: Phan
authors.forename: Hien Xuan
authors.initials: HX
authors.lastname: Nguyen
authors.forename: An Van
authors.initials: AV
authors.lastname: Le
authors.forename: Alberto
authors.initials: A
authors.lastname: Alberti
mesh_terms: D000328:Adult; D016667:Bacterial Capsules / Q000235:genetics*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D006801:Humans; D016920:Meningitis, Bacterial / Q000175:diagnosis* / Q000382:microbiology; D008969:Molecular Sequence Data; D057089:Pathology, Molecular / Q000379:methods*; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D017422:Sequence Analysis, DNA; D065288:Serogroup; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D017011:Streptococcus suis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D014744:Vietnam
chemical_list: D004269:DNA, Bacterial; D021903:DNA, Ribosomal Spacer