title: [Genetic control of the ability of Sh. flexneri to produce a lethal effect on macrophages. I. Study of the possible extrachromosomal nature of the cyt+-determinant].
abstract: It was shown that cyt+-determinant could not be eliminated when the Sh. flexneri cultures were treated with ethidium bromide under the regimen providing the elimination of the F'lac-factor in a part of shigellae population. The cytotoxic Sh. flexneri strains which acquired the R-factor transmitted the multiple drug resistance to the cyt minus -strain of Sh. flexneri, but not the cyt+-properties. There was found no correlation between the cytoxicity of the Sh. flexneri strains and their capacity to mobilize the nontransmissive STr-ex-episome in the triple cross experiments. The results obtained were in favour of the chromosomal nature of cyt+-determinants controlling the capacity of Sh. flexneri to produce the lethal action on the macrophages.
mesh_terms: D004305:Dose-Response Relationship, Drug; D004352:Drug Resistance, Microbial; D004996:Ethidium / Q000494:pharmacology; D005111:Extrachromosomal Inheritance; D008264:Macrophages; D012763:Shigella flexneri / Q000187:drug effects
chemical_list: D004996:Ethidium
vernacular_title: Geneticheskiĭ kontrol' sposobnosti Sh. flexneri okazyvat' letal'noe deĭstvie na makrofagi. Soobshcheni. I. Izuchenie vozmozhnoĭ ékstrakhromosomnoĭ prirody cyt+-determinanta