title: Rapid detection of Haemophilus influenzae and Haemophilus parainfluenzae in nasopharyngeal swabs by multiplex PCR.
abstract: OBJECTIVE
  To establish multiplex PCR-based assays for detecting H.influenzae and H.parainfluenzae. And the PCR-based assays were applied to detect the carriage rates of H.influenzae and H.parainfluenzae in nasopharyngeal swab specimens which were collected from healthy children.
  
  
  METHODS
  Multiplex primers for species-specific PCR were designed by using DNAstar soft based on the sequences of 16S rRNA genes from genus Haemophilus to detect H.influenzae and H.parainfluenzae.
  
  
  RESULTS
  The sensitivity of the 16S rRNA PCR assay for detecting H.influenzae and H.parainfluenzae was 97.53% and 100% respectively, and the specificity was 95.89% and 96.63% respectively. Youden's Index on the ability to detect H.influenzae and H.parainfluenzae was 0.9342 and 0.9663 respectively. 666 nasopharyngeal swab specimens were collected from healthy children. The detection rates of H.influenzae and H.parainfluenzae were 14.11% and 16.07% respectively by using isolation and culture methods. The detection rates of H.influenzae and H.parainfluenzae were 43.54% and 57.96% respectively by 16S rRNA PCR assays. The carriage rates of serotypes a, b, c, d, e, f and non-typeable isolates were 0% (0/666), 0.15% (1/666), 1.20% (8/666), 0.15% (1/666), 1.20% (8/666), 1.80% (12/666), 95.50% (636/666) respectively.
  
  
  CONCLUSIONS
  The multiplex PCR assays were very rapid, reliable and feasible methods for detection of H.influenzae and H.parainfluenzae in pharyngeal swab specimens which were compared to conventional isolation and culture methods. 95.5% of H.influenzae strains in healthy children were nontypeable. The encapsulated or typable strains were mainly three serotypes which was c, e, and f serotype.
authors: State Key Laboratory for Infectious Diseases Control and Prevention, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors: Guo Zhong
authors: GZ
authors: Tian
authors: Li Juan
authors: LJ
authors: Zhang
authors: Xiao Lei
authors: XL
authors: Wang
authors: Li
authors: L
authors: Zhang
authors: Shu Feng
authors: SF
authors: Li
authors: Chang Mei
authors: CM
authors: Gu
authors: Jian
authors: J
authors: Sun
authors: Bu Yun
authors: BY
authors: Cui
mesh_terms: D006193:Haemophilus influenzae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D044135:Haemophilus parainfluenzae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods*; D009305:Nasopharynx / Q000382:microbiology*; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012680:Sensitivity and Specificity
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S