BIFIDOBACTERIA

From Big Medical Encyclopedia

BIFIDOBACTERIA (Latin bifidus divided in two + bacteria) — the anaerobic sporeless lactobacilli inhabiting intestines of the person and animals. They make 95 — 98% of all intestinal microflora. B. for the first time described Tissye (H. Tissier, 1900) as you. bifidus communis. B. represents group of heteromorphic microorganisms for which taxonomical criteria are not finalized.

Bact. bifidum. The branching sticks with club-shaped thickenings on the ends (coloring across Gram; h900).

Oryol Janszen (S. Orla-Jensen, 1924) gave the name to the main representative of this Bacterium bifidum group, from to-rogo the modern name of the sort Bifidobacterium entering in this is made. Lactobacillaceae. H. A. Krasilnikov carries B. to this. Mycobacteriaceae; Prevo (A. R. Prevot, 1961), R. Schuler and soavt. (1968) — to intestinal sporeless actinomycetes; Kandler (O. of Kandler, 1970) defines situation B. as intermediate between lactobacilli and actinomycetes.

The sort B., on classification of Reuters (G. Reuter, 1964), includes 16 types which often have insignificant distinctions on fermentation of separate carbohydrates and abilities to grow at an elevated temperature (43 — 46 °).

For specification of taxonomical situation B. it is recommended to use features of carbohydrate metabolism (fruktozo-6-phosphate, poliglitserol-phosphatides), the sequence of amino acids in structure of murein of a cell wall and feature of nucleotide composition of DNA. According to the last test of 60% of couples of bases entering B. make a guanine + tsitozin (HZ type). Studying of a homology of DNA B. [V. Scardovi et al.] did not give the grounds to definition of interrelationship of separate types.

According to the microbiological characteristic of B. represent sporeless gram-positive sticks 2 — 5 microns long, 0,3 — 0,6 microns wide, polymorphic, often branching, with club-shaped thickenings on the ends (fig). Polymorphism is more sharply expressed in old cultures, in fluid mediums. At special coloring the expressed granularity reminding granules at korinebakteriya is observed in different degree.

B. at primary allocation from native material — strict anaerobe bacterias. At the subsequent cultivation separate types can gain tolerance to oxygen (The sharper, etc., 1968). B. in anaerobic jar are grown up or during the use of inert gases, on the Wednesdays which are usually applied to cultivation of anaerobe bacterias (hepatic, milk, in different modifications), by pH 7,0 — 7,2. Optimum temperature of cultivation 37 °, but some types of B. (Bact. bifidum, Bact, termophylus) can grow at a temperature up to 46,5 ° that is used as one of tests of their identification.

B. ferment carbohydrates with formation of milk and acetic acids, without carbonic acid. On the developed number of carbohydrates including except standard, pectine sugar, cellobiose, melicitose, representatives of separate types are active concerning 2 — 3 carbohydrates (Reuters, 1971). On the nature of fermentation of carbohydrates J. Dennert recommends to differentiate

B. B. biotypes do not produce hemolysins, a catalase, nitrous vitriol, a zhelatinaza, urease; do not form hydrogen sulfide, do not use citrate as a source of carbon; synthesize vitamins B 1 , K. Have antagonistic activity in relation to enteropathogenic and putrefactive bacteria. For the person and animals — a nepatogenna.

B.'s identification is based on the microbiological characteristic — polymorphism, gram-positive coloring in the absence of sporogenesis, growth in strictly anaerobic conditions, fermentation of a certain set of carbohydrates only before formation of acid.

All-biological value B. is defined by their antagonistic and vitaminsinteziruyushchy activity. That circumstance that at the diseases of intestines (nonspecific ulcer colitis, various forms of dyspepsias) accompanied with dysbacteriosis, B.'s number sharply decreases, testifies to their significant role in formation of a normal microbic coenosis.

See also Bifidumbacterium .


Bibliography: Zlatogorov S. I. The doctrine about microorganisms, the p. 3, century 1, page 232, Pg., 1918; P e r e of t of c of JI. G. Znacheniye of normal microflora for a human body, M., 1955; Semenikhinav. E. Biologiya of bifidobacteria, Works Vsesoyuz. nauch. - issled. in-that molochn. prom-st, century 26, page 69, M., 1968; To a n d 1 e of O. of Aminoacid sequence of the murein and taxonomy of the genera Lactobacillus Bifidobacterium, Leuco-nostoc and Pediococcus, Int. J.System. Bact., v. 20, p. 491, 1970, bibliogr.; P of έ at about t A.R. Traite de syst6matique bacterienne, P., 1961; Reuter G. Designation of type strains for Bifidobacterium species, Int. J.system. Bact., v. 21, p. 273, 1971, bibliogr.; S with a r d about v i V. o. Deoxyribonucleic acid homology relationships among species of the genus Bifidobacterium, ibid., p. 276, Schuler R., R up per t A. u. Muller F. Die Mikroorganismen der Bifidusgruppe (Syn. Lactobacillus bifidus), Milchwissenschaft, S. 356, 1968; T i s s i e r H. Recherches sur la flore intestinale des nourrissons, P., 1900.

D. G. Kudlay.

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