title: Chemical and biological properties of endotoxin from Leptospira interrogans serovars canicola and icterohaemorrhagiae.
abstract: 1. Endotoxin-like activity was extracted with phenol-chloroform-petroleum either (PCP) from Leptospira interrogans serovars icterohaemorrhagiae and canicola. Chemical analysis of leptospiral cells obtained from the PCP extract indicated the following distribution of lipopolysaccharide (LPS), protein and polysaccharide in mg/ml: 3.0, 4.5 and 1.0 for icterohaemorrhagiae and 3.3, 5.6 and 1.5 for canicola. 2. The preparations presented several biological activities: positive Limulus test (1.0 pg/ml) for icterohaemorrhagiae and canicola PCP extract and 0.5 pg/ml for E. coli O111:B4 LPS, lethality for chicken embryos (LD50 45, 25 and 1.0) for icterohaemorrhagiae, canicola and E. coli O111:B4 LPS, pyrogenicity in rabbits with an average increase in rectal temperature of 0.6 degrees C, 0.9 degrees C and 2.2 degrees C for canicola, icterohaemorrhagiae and E. coli O111:B4 LPS, reacted with complement inhibiting the lysis of sheep red blood cells, 62%, 75% and 90% for 2.0 micrograms/ml of icterohaemorrhagiae, canicola PCP extract and E. coli O111:B4 LPS. The PCP extract showed no cytotoxicity on chicken embryo fibroblasts and epithelial cells. 3. These results demonstrate that Leptospira endotoxin activity is similar to E. coli O111:B4 lipopolysaccharide.
authors.affiliation: Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil.
authors.forename: L
authors.initials: L
authors.lastname: De-Souza
authors.forename: M C
authors.initials: MC
authors.lastname: Koury
mesh_terms: D000818:Animals; D002642:Chick Embryo; D015941:Complement Hemolytic Activity Assay; D004731:Endotoxins / Q000032:analysis / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification / Q000633:toxicity; D004926:Escherichia coli; D007114:Immunization; D007921:Leptospira interrogans / Q000145:classification; D041341:Leptospira interrogans serovar canicola / Q000145:classification; D007928:Lethal Dose 50; D008033:Limulus Test; D011817:Rabbits; D012703:Serotyping; D012790:Shwartzman Phenomenon / Q000139:chemically induced
chemical_list: D004731:Endotoxins