{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T17:50:41Z","timestamp":1760205041200},"reference-count":0,"publisher":"American Society for Microbiology","issue":"2","license":[{"start":{"date-parts":[[1981,5,1]],"date-time":"1981-05-01T00:00:00Z","timestamp":357523200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Infect Immun"],"published-print":{"date-parts":[[1981,5]]},"abstract":"<jats:p>\n            Rats were examined for their susceptibility to infection with\n            <jats:italic>Legionella pneumophila.<\/jats:italic>\n            Different strains of\n            <jats:italic>L. pneumophila<\/jats:italic>\n            representing serogroups 1 to 4 were tested (Philadelphia 1 and 2, Togus 1, Bloomington 2, Los Angeles 1, and the recently isolated LD-8 from the epidemics in V\u00e4steraas, Sweden). When about 9 \u00d7 10\n            <jats:sup>8<\/jats:sup>\n            bacteria, or 6 \u00d7 10\n            <jats:sup>8<\/jats:sup>\n            colony-forming units, were injected intraperitoneally, only rats infected with the LD-8 strain showed signs of illness. They became ill within 4 to 6 h and usually died within 24 h with septicemia and signs of circulatory collapse. Bacteria killed by heating at 100\u00b0C for 15 min lost their pathogenicity. Rats that were preimmunized with the Philadelphia 1 strain (same serogroup as LD-8), regardless of the route of immunization (subcutaneous, intraperitoneal, or intravenous), developed resistance to subsequent infection with LD-8. This resistance was serogroup specific and could be passively transferred to nonimmune animals with syngeneic immune serum or immunoglobulin fractions of serum. Antiserum or gamma globulin-enriched serum fractions from sheep with specificity for the Philadelphia 1 or Togus 1 strains also protected rats from the lethal effect of strain LD-8. The kinetics of the antibody and blood leukocyte response to immunization with the Philadelphia 1 strain of\n            <jats:italic>L. pneumophila<\/jats:italic>\n            in normal rats was investigated. During week 1 after intravenous injection the rats developed a marked lymphocytosis, which lasted for at least 1 week. The antibody response, as measured by indirect immunofluorescence or by a modification of the microagglutination method which we describe here, reached a peak during week 2 after immunization. Splenectomized rats were also resistant to infection with the Philadelphia 1 strain, but their antibody responses were substantially lower than those of their sham-operated littermates.\n          <\/jats:p>","DOI":"10.1128\/iai.32.2.805-812.1981","type":"journal-article","created":{"date-parts":[[2020,1,1]],"date-time":"2020-01-01T05:26:31Z","timestamp":1577856391000},"page":"805-812","update-policy":"http:\/\/dx.doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":22,"title":["Immune Defenses Against\n            <i>Legionella pneumophila<\/i>\n            in Rats"],"prefix":"10.1128","volume":"32","author":[{"given":"Bent","family":"Rolstad","sequence":"first","affiliation":[{"name":"Norwegian Defense Microbiological Laboratory, Oslo, Norway"},{"name":"Anatomical Institute, University of Oslo, Oslo, Norway"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bj\u00f8rn P.","family":"Berdal","sequence":"additional","affiliation":[{"name":"Norwegian Defense Microbiological Laboratory, Oslo, Norway"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"235","container-title":["Infection and Immunity"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/iai.32.2.805-812.1981","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/iai.32.2.805-812.1981","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,3,5]],"date-time":"2022-03-05T13:34:21Z","timestamp":1646487261000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/iai.32.2.805-812.1981"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1981,5]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1981,5]]}},"alternative-id":["10.1128\/iai.32.2.805-812.1981"],"URL":"https:\/\/doi.org\/10.1128\/iai.32.2.805-812.1981","relation":{},"ISSN":["0019-9567","1098-5522"],"issn-type":[{"value":"0019-9567","type":"print"},{"value":"1098-5522","type":"electronic"}],"subject":[],"published":{"date-parts":[[1981,5]]},"assertion":[{"value":"1981-05-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}