PCR METHODS AND PLASMID PROFILE ANALYSIS FOR CHARACTERIZATION OF HISTOPHILUS-OVIS STRAINS

The value of polymerase chain reaction (PCR)-based DNA fingerprinting and plasmid profile analysis for differentiation of Histophilus ovis i solates was assessed. Nineteen isolates of H, ovis were typed by PCR-r ibotyping, repetitive extragenic palindromic element (REP)-PCR and ent erobacterial repetitive intergenic consensus (ERIC)-PCR, These methods distinguished five types by PCR-ribotyping, 11 types by REP-PCR and s even types by ERIC-PCR. The ribotyping method produced a relatively si mple pattern and a small number of distinct types and was useful for d ifferentiation of H, ovis from the phenotypically similar organism, Ha emophilus somnus. REP- and ERIC-PCR both produced complex banding patt erns, but increased the discrimination between strains. Plasmids were found in 12 of the 19 isolates and there were four different plasmid p rofiles, A combination of the PCR methods and plasmid profile analysis provided a high resolution typing method for H, ovis.