LYSOTYPY (synonym. whether
a zotipirovaniye, phage marking, phage typing) — a method of identification and division of bacteria in a look or serotin (serovar) by means of a set of specific (standard) bacteriophages.
T. — one of sensitive methods of a phage diagnosis (see) pathogenic bacteriums. The method is used in epidemiology for interpretation of bonds between epidemic flashes and separate diseases, detection of sources and ways of transfer of contagiums, duration of a carriage, and also in researches for establishment of identity of various strains of bacteria. Phages type bacteria of the sorts Salmonella, Shigella, Escherichia, Proteus, Vibrio, Pseudomonas, Streptococcus, Staphylococcus, Mycobacterium, Coryneba-cterium, etc. Obviously, opportunity F. exists for all species of bacteria, its implementation depends on variability of receptors of standard phages, features of genetic fund of strains of bacteria.
For the first time F. offered in 1938 Kreygi and Yens (J. Craigie, S. Yen) for differentiation of various strains of the causative agent of a typhoid — Salmonella typhi on sensitivity to 11 standard phages.
T. consists in crops by a lawn of the examinee of a strain of bacteria on a surface of the dense environment and drawing on crops of drops of a phage (see the Bacteriophage). The bacteria sensitive to a phage are determined by a zone of their lysis (emergence of plaques) on site of the put drop of a phage. The phage is put in working test cultivation, i.e. in the maximum tenfold cultivation, at Krom on site of contact of a phage with the test strains of bacteria sowed on a medium confluent (full) or their semi-confluent (incomplete) lysis is formed.
The bacteria of one look or a serotype which are identically reacting (lysing) at interaction with phages of standard set of standard phages in working test cultivations belong to the same fagotip (fagovar). For F. use virulent and moderate a phage. By studying of a range of their action on strains of bacteria of various origin make the scheme F. Specificity of a lytic response of a phage depends on existence on a surface of a cell wall of bacteria of receptors for this phage, to-rye can disappear or appear as a result of changes in the genetic device of bacteria (chromosomes and extra chromosomal factors of heredity). Existence in a bacterium closely related to a standard phage of the prophases (see L an isogeny) repressing (suppressing) its reproduction in cytoplasm is of great importance. Resistance of a bacterial cell to a standard phage can be caused it by specific enzymes — restriktaza-m, destroying phage DNA. Restriktaza of bacteria can be determined by a chromosome, phages or the corresponding plasmids (see).
Interaction of a phage with a bacterium can depend on h-mutations of a genome of a phage, causing changes in structure of its shoots that complicates or facilitates adsorption of a phage on receptors of a cell wall of bacteria.
There are various approaches to creation of schemes of a lysotypy of bacteria. One of such approaches was applied in 1938 by Kreygi and Ian and modified by Anderson and Williams (E. S. Anderson, R. E. Williams) for creation of the scheme of a lysotypy of S. typhi, in a cut are used as standard phages derivatives of one phage of Vi-II of A type. Received a phage designate capital letters of the Latin alphabet or in the Arab figures. In practice for definition of a fagotip results of typing of a strain of bacteria compare to data of the standard table. Determine by standard phages of the International center of a lysotypy fagotip at 80 — 100% of strains of S. typhi.
Other approach is applied to creation of the vast majority of schemes of a lysotypy of other pathogenic bacteriums. In them use standard a phage of a different origin. Fagotipa of bacteria distinguish on a combination of phages, lizpruyu-shchy them in working test cultivations. Fagotip of bacteria determine by the range of its sensitivity recorded in the table to different standard phages and designate randomly in figures, letters, names of settlements where bacteria of these fagovar are for the first time allocated. Ranges of sensitivity of bacteria to phages are presented in tables. The number of fagotip of bacteria can be estimated in several tens. In Felix's scheme — Kallou, offered in 1951, are subdivided by S. schottmuelleri by means of 11 standard phages into 10 fagotip — 1, 2, For, 3al, 3f, Jersey, Beccoles, Taunton, Dundee, BAOR — and 30 subfagotip. In 1959 Shol-tens (R. T. Scholtens) on the basis of this scheme created the scheme of a lysotypy, in a cut interaction of bacteria of a certain fagotip with standard phages is connected with its lysogenic properties (existence in bacteria of prophases).
In the scheme of a lysotypy of plazmokoaguliruyushchy golden stafilokokk (see) fagotip bacteria designate in figures of standard phages, to-rye it lyse in 10 — 100 working test cultivations. E.g., the strain of bacteria lysing with phages 47, 53 and 54 receives the name «fagotip 47/53/54 +» (the sign «+» specifies that the strain poorly lyses with other phages). Exist a phage, to-rye often lyse staphylococcus together with other phages that gave the chance to distinguish from staphylococcal phages and according to fagotip of bacteria 4 groups: I, II, III and IV. It allowed to abolish bulky tables schemes of a lysotypy. The scheme of a lysotypy of stafilokokk is standardized and improved in the International center of a fagotiii-rovaniye. A set of phages of «H» is created, to-ry periodically changes in connection with increase in medicinal stability of stafilokokk. In 1974 set of 21 phages is approved: group I — 29, 52, 52A, 80, II - ZA, ZS, 55, 72, III — 6, 42E, 53, 54, 75, 77, 83, 84, 85, out of groups — 81, 94, 95, 96, on antigenic structure a phage are subdivided into 3 serological groups (And, B and F).
T. stafilokokk it is important for Epi-demiol. the analysis of food poisonings of a staphylococcal etiology and staphylococcal intrahospital infections (see Toxicoinfections food). For hospitals endemic were fagotipa of stafilokokk 80/81, 52/52A/80, 77, 85/85, etc.
The scheme of a lysotypy of toxicogenic causative agents of diphtheria (see) and their not toxicogenic analogs includes the name of a fagotip of bacteria and information on its sensitivity to standard phages, to-rye designate letters of the Latin alphabet. The Fag causing strong reactions are specified by capital letters, weak reactions — lower case. In the name of a fagotip of a letter, corresponding to certain phages, are placed in alphabetical order that allows to reveal relationship or distinction of strains. The strain lysing with phages
And, C and D in the form of a confluent lysis, and a phage of F — in the form of single plaques, receives the name «ACDf».
Bibliography: Akatov A. K. and Zueva of V. S. Stafilokokki, M., 1983;
Krylova M. D. Lysotypy of bacteria, M., 1963, bibliogr.; Covered the island and M. D. and Lysenko A. M. Studying of a homology of DNK group I, II and III So-rynebacterium of diphtheriae v. gravis, Co-rynebacterium ulcerans and Corynebacterium pseudotuberculosis (ovis), Zhurn. mikr., epid. and immun., No 3, page 48, 1984; H and r joint stock company and d z e I. G. and H and N and sh in and l and T. G. Typing of S. typhimurium by means of the selected phages, in the same place, No. 3, page 72, 1974; Yakovleva O. N., Romanov Yu. M. and Petrovsky V. G. Influence of R-plasmids of strains of Salmonella typhimurium of various origin on virulence of salmonellas, in the same place, No. 9, with - 40, 1983; And p-derson E. S. a. Williams R. E-Bacteriophage typing of enteric pathogenes and staphylococci and its use in epidemiology, J. din. Path., v. 9, p. 94, 1956;
Boven C. P. A. Restriction and modification of phages in staphylococcal phage typing, Ann. N. Y. Acad. Sci., v. 236, p. 376, 1974; Craigie J.
Yen of Page H. The demonstration of types of B.
typhosus by means of preparations of type II Vi phage, Canad. pubi. Hlth J., y. 29, p. 448, 1938; Z ierdt of Page H.
o. Computer analysis of Staphylococcus aureus phage typing data from 1957 to 1975, citing epidemiological trends and natural evolution within the phage typing system, Appl. environ. Microbiol., v. 39, p. 623, 1980., M. D. Krylova.