Detection of type b capsule gene of Haemophilus influenzae by multiplex PCR

Objective To detect Haemophilus influenzae type b strains isolated from children in Hangzhou by multiplex PCR methods.MethodsAll Haemophilus influenzae strains were analyzed by multiplex PCR.BexA-primers and b capsular type-specific gene primers were used as golden standard.ResultsOf all the 399 clinical strains isolated from children during the period from 2001-2002 and 2006-2007,297 strains(74.44%) were nontypeable,while 102 strains(25.56%) were typeable and only 1(0.25%) of them was type b,respectively.PCR results showed that of all the 102 strains which showed positive with the slide agglutination method,101 were positive and only 1 was negative while 2 strains showed positive from the 297 strains which were nontypeable.The results showed consistent with the serotype with the sensitivity of 99.02% and specificity of 99.33%.ConclusionsWith genotyping success rate and detection rate for Hib reaching 100%,the investigation overcame the shortcomings of serotyping by the technology of bex-PCR for b-type joint capsule gene-specific multiplex PCR.