Molecular characterization of isolates of Haemophilus paragallinarum from China by ribotyping

Abstract

Ribotyping profiles were determined for 12 Page serovar A isolates of H. paragallinarum from 5 outbreaks of infectious coryza in commercial layer flocks in Hebei province in China between 1986 and 1993. Four enzymes were used to generate restriction digests of chromosomal DNA: Hae III, Hin dIII, Hpa II and Ssp I. The digests were probed with a digoxigenin-11-dUTP-labelled DNA probe produced by PCR amplification of the 16S rDNA of the type strain of H. paragallinarum . Only one profile was seen among the 12 isolates when using either Hin dIII or Ssp I. Three different ribotype profiles were seen with Hpa II, while 4 different profiles were detected with Hae III. Cluster analysis of the profiles generated by Hpa II and Hae III corresponded with the known epidemiological history of the isolates. This appears to be the first report on molecular characterization of isolates of H. paragallinarum from China.