Molecular epidemiological study of Haemophilus influenza serotype b strains of tained from children with meningitis.

我们报告了从脑膜炎患儿脑脊液中分离的30株b型流感嗜血杆菌的流行病学研究。对HIB菌株进行生物分型，产β-内酰胺酶试验，并通过长片段核糖体分型、随机扩增多态性DNA分析和脉冲场凝胶电泳法进行基因组限制性片段长度多态性分析。其中22株(73%)为生物型I型。采用长片段聚合酶链式反应-核糖体分型技术对30株Hib菌株进行分型研究，结果表明，30株Hib菌株之间没有明显的多态性，但用两组引物进行的随机扩增多态性分析显示了两个明显的亚型：一个亚型属于生物型II，第二个亚型属于生物型I和IV。每个亚型用PFGE-RFLP结合SmaI酶切分型。临床分离的Hib毒株的基因分型可能有助于阐明社区感染的传播途径、地方性和疫苗失败的原因。

We report an epidemiological study of 30 Haemophilus influenzae serotype b (Hib) strains derived from the cerebrospinal fluid of children with meningitis. The Hib strains were biotyped, tested for β-lactamase production, and genotyped by long PCR-ribotyping, random amplified polymorphic DNA (RAPD) analysis, and genomic DNA restriction fragment length polymorphism (RFLP) analysis by pulsed-field gel electrophoresis (PFGE). The phenotypic study characterized 22 of the strains (73%) as biotype I. A genotypic study using long PCR-ribotyping with HaeIII restriction digestion showed no polymorphisms among these 30 Hib strains, but RAPD analysis with two sets of primers demonstrated two distinctive subtypes : one typical of the strains of biotype group II and the second characteristic of the strains of biotype groups I and IV. Each RAPD group was subtyped into several genotypic groups by PFGE-RFLP with SmaI digestion. The genotyping of clinically isolated Hib strains may help to elucidate transmission routes in community infections, endemicity, and the reasons for vaccine failure.