title: Death and lysis of leptospirae when cultured in asbestos-filtered growth media.
abstract: Death and lysis of leptospirae, when cultured in asbestos-filtered bovine albumin polysorbate 80 media, was quantitated. The pathogens (virulent and avirulent) required 2 x 10(6) cells/ml to initiate growth in such media, whereas inocula of 2 to 20 cells/ml grew in control medium. Saprophytic leptospirae initiated growth from 2 cells/ml in asbestos-filtered medium as well as control medium. The adverse action of asbestos-filtered medium was not removed by storage of medium for 2 years at 25 C and was not diminished when such medium was frozen at -80 C. Washing with water, HCl and NaHCO(3)-NaCl, citric acid, and medium components did not remove the lytic activity associated with asbestos-filtered culture medium. Continuous subculture in asbestos-filtered medium was possible from large inocula; however, upon subsequent dilution and reinoculation into asbestos-filtered media, there was no evidence of acquired resistance, and all pathogens failed to grow.
mesh_terms: D000372:Agglutination Tests; D000942:Antigens, Bacterial / Q000032:analysis; D001194:Asbestos; D001431:Bacteriological Techniques; D001433:Bacteriolysis; D003470:Culture Media; D003720:Densitometry; D005374:Filtration; D007919:Leptospira / Q000254:growth & development* / Q000276:immunology / Q000472:pathogenicity; D012703:Serotyping; D012710:Serum Albumin, Bovine; D013045:Species Specificity; D013997:Time Factors; D014774:Virulence; D014867:Water
chemical_list: D000942:Antigens, Bacterial; D003470:Culture Media; D014867:Water; D001194:Asbestos; D012710:Serum Albumin, Bovine