GROWTH, VIRULENCE, AND IMMUNOGENICITY OF LEPTOSPIRA-INTERROGANS SEROTYPE SZWAJIZAK

  • 1 January 1977
    • journal article
    • research article
    • Vol. 38  (9) , 1421-1424
Abstract
L. interrogans serotype szwajizak was characterized by its growth in polysorbate 80-bovine albumin medium, its virulence and course of infection in laboratory animals and its immunogenicity. Growth of this organism was continous and vigorous at 29.degree. C and 37.degree. C in liquid medium for 10 serial subcultures. Some specific lots of agar were superior to other agars if tested for the ability to support the growth of small inoculums. Individual colonies resulted from growth of small inoculums on solid polysorbate medium. Virulence of the organisms did not appear to be altered by 10 serial subcultures in liquid medium incubated at 29.degree. C. The estimated median lethal dose of L. interrogans szwajizak for hamsters by the i.p. route was 2 cells. Virulence, infectivity and pathogenicity of L. interrogans szwajizak were shown in the hamster and the guinea pig. Protection results indicate the heat-inactivated L. interrogans szwajizak bacterin was a substantially better immunizing agent than the chemically inactivated bacterin. L. interrogans serotype hardjo bacterins provided hamsters some protection against death if challenge exposed with L. interrogans szwajizak, but afforded no protection against infection.