Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: February 21, 2003
Publication Date: April 20, 2003
Citation: ZEHR, E.S., TABATABAI, L.B. COMPARISON OF HAEMOPHILUS PARASUIS SEROTYPES BY RANDOM AMPLIFICATION OF POLYMORPHIC DNA AND PROTEIN PROFILES. 103rd GENERAL MEETING OF THE AMERICAN SOCIETY FOR MICROBIOLOGY. 2003. Abstract p. 679, #Z-024. Technical Abstract: Background: Haemophilus parasuis (HP) is the causative agent of Glässer's disease and is considered a re-emerging pathogen of swine in high-health status herds. However, an effective commercial vaccine is not available. Historically, classification of HP serotypes has been through pathogenicity studies and the standard culture/biochemical, agar-gel diffusion, and the rapid identification system (RapIDNH) methods. Information on the capsular polysaccharide, lipopolysaccharide, outer membrane proteins, fimbriae, toxins, periplasmic proteins, and DNA of HP is not available. To date, only 16S RNA profiles of HP serotypes have been compared. We initiated this study to compare random amplification of polymorphic DNA (RAPD) analysis and protein profiles of HP serotypes and field isolates. Methods: The DNA and protein profiles of 15 type strains and 6 field isolates of HP were studied by similarity analysis using the Dice algorithm to determine relatedness among the strains and isolates. The RAPD analysis utilized 3 different 10mer primers in 45 cycles of low stringency polymerase chain reaction (PCR) after intact bacterial cell populations were lysed by a "hot start" step. The protein profiles were generated from Coomassie Brilliant Blue-stained SDS-PAGE of cell-free lysates prepared by sonication and centrifugation of HEPES-washed cells. Results: Different and reproducible DNA and protein fingerprints were found among the 21 strains and field isolates studied. Similarities and differences existed among nonvirulent, virulent, and highly virulent strains, grouped according to their pathogenicity. Moreover, some of the field isolates were distinct from their corresponding HP type strains. Two serologically typed field strains maintained in culture for two years were different from their corresponding HP type strains using the RAPD analysis. Conclusion: The RAPD analysis and protein profiles of cell-free lysates may be useful techniques for comparing HP serotypes. Our results confirm other reports that HP undergoes phenotypic changes due to environmental pressures.