COMPARISON OF VARIOUS HEMOPHILUS SOMNUS STRAINS

Google Scholar
  • 1 January 1977
    • journal article
    • research article
    • Vol. 41  (4) , 380-388
Abstract
Sixty-eight H. somnus strains isolated from the bovine in Canada and the USA were compared. In media enriched with 5% ovine serum, 5% bovine serum and 10% yeast extract, H. somnus fermented glucose, levulose, maltose, mannitol, mannose, sorbitol, trehalose and xylose, but failed to ferment arabinose, dulcitol, galactose, inositol, lactose, raffinose, rhamnose, salicin and sucrose. The organisms acidified litmus milk, produced cytochrome oxidase, indole and H2S and reduced nitrates to nitrities. The motility, methyl-red, acetylmethyl-carbinol, urease, catalase, citrate, malonate, lysine, ornithine and arginine tests were negative. H. somnus was resistant to lincomycin, neomycin and triple sulfa, but susceptible to ampicillin, chloramphenicol, streptomycin, penicillin and tetracycline. No antigenic differences were noted between strains when tested against rabbit antisera of 8 strains using agglutination, complement-fixation, immunodiffusion and counterimmunoelectrophoresis tests. Low titer cross-reactions were found in the agglutination tests with some of the anti-H. somnus rabbit sera with Actinobacillus lignieresi and Moraxella bovis. No distinct antigenic similarities to 9 other species of pathogenic bacteria of animal origin were found. No difference was observed between H. somnus isolates from Ontario and those from western Canada and the USA.