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M D Krylova

Publications and source records attributed to M D Krylova.

4 recordsLinked to original sources
PubMed1977

[The species C. diphtheriae].

Corynebacteria (C. diphtheriae var. gravis, mitis, minimus, intermedius, C. belfanti, C. ovis, C. ulceraus) producing diphtheria toxin are found as variants sharply differing from one another morphologically (from long branching rods to coccobacilli), culturally, biochemically and by other signs. The toxin synthesis in them was determined by genetically heterogeneous prophages tox+; tox+ virus exchange is possible between the corynebacteria. Since production of specific toxin, the cardinal sign of C. diphtheriae species, is connected with the genoms of genetically heterogeneous viruses tox+, the circle of whose hosts is very wide, it can be supposed that there is no genetically homogeneous taxonomic category "diphtheriae species". Several species of corynebacteria--lysogenized (toxigenic) or capable of being lysogenized (nontoxigenic) with tox+ viruses are included into the composition of the corynebacteria groups which medicine considers as "species" for over 80 years. A possiblity of becoming a diphtheria causative agent is determined by the capacity of corynebacteria to become infected with the circle of viruses tox+ the DNA of which can become stably integrated with the gene of this bacterium. The mentioned approach to taxonomy is possibly applicable to microorganisms in which the pathogenicity signs (the toxin) were determined, as in C. diphtheriae, in the virus genoms (Bac. botulinus).

Bacteriophage Typing↗
PubMed1975

[Use of the corycin test and of bacteriophage typing for genetic marking of corynebacteria with reference to C. diphtheriae of the gravis type].

Nontoxigenic C. diphtheria, fermenting starch, of convertible phage types ABCDFCH, ABCDFG, ABCDF, ABCD, ABD, ACDf, CDf, AF and A, and also strains of nonconvertible bacteriophage types I, H and K proved to be noncoricynogenic in the corycine test and weakly sensitive to bacteriocin of the No. 3463 test strain (a study was made of a total of 502 strains). Strains (383) isolated from 354 patients and carriers--starch-fermenting and toxigenic to the gravis type--were toxigenic were lysed by a combination of bacteriophages O, P, Q, R, S, T produced an active bacteriocine against the test strains No. 23 BC, and were insensitive to bacteriocine of the strain No. 3453. Strains of phage type G(g) were noncorycinogenic. Only one strain of phage type G, which produced corycine, active against the test strain No. 23 BC served as an exception. With the aid of phages A, B, C, D, F, G, H, I, K it was possible to separate 244 strains of the phage type G(g) into 3 phage types--bc, ABfGH and Abg. Strains of phage type ABfGH were noncorycinogenic; the only strain of phage type bG available produced bacteriocine.

Bacteriocins↗