title: [Cytopathogenic effect of diphtheria exotoxin in cultured chick embryo fibroblasts].
abstract: One hundred fifty strains of Corynebacterium diphtheriae were studied from patients with symptoms of diphtheria and from healthy persons. 136 strains (90.67%) belonged to the mitis biotype, 12 (8.0%) and 2 (1.33%) to gravis and intermedius biotypes respectively. Toxigenicity was determined by traditional in vivo methods with rabbits and plaque immunodiffusion in KL-virulence medium. From the 136 mitis biotype strains studied, 130 (95.58%) showed positive toxigenicity by both methods and 11 strains (91.66%) from gravis biotype and 2 (100%) of intermedius biotype gave same results. The cellular cytotoxicity of the diphtheriae toxin was tested on culture of chicken embryo fibroblast and were positive in 132 (97.05%) strains of mitis biotype, and in all strains of gravis and intermedius biotypes. These results suggest that the cytotoxicity test seems to be a more sensitive method for detecting diphtheriae toxin production.
authors.affiliation: Instituto de Investigaciones Clínicas, Facultad de Medicina, Universidad de Zulia, Maracaibo, Venezuela.
authors.forename: E
authors.initials: E
authors.lastname: Teruel-López
authors.forename: R
authors.initials: R
authors.lastname: Cárdenas-Cedeño
authors.forename: L
authors.initials: L
authors.lastname: Avila
authors.forename: B
authors.initials: B
authors.lastname: Ramos
mesh_terms: D000818:Animals; D001681:Biological Assay; D002478:Cells, Cultured; D002642:Chick Embryo; D003353:Corynebacterium diphtheriae / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism; D004165:Diphtheria / Q000382:microbiology; D004167:Diphtheria Toxin / Q000032:analysis / Q000633:toxicity*; D005347:Fibroblasts / Q000187:drug effects* / Q000473:pathology; D006801:Humans
chemical_list: D004167:Diphtheria Toxin