MYCOPLASMATACEAE

From Big Medical Encyclopedia

MYCOPLASMATACEAE — family of an order Mycoplasmatales of the class Mollicutes consisting of the sterolzavisimy prokariot deprived of a cell wall, having a three-layered cytoplasmic membrane outside of a cell. Two sorts — Mycoplasma and Ureaplasma concern to family. M grow in a type of the typical colonies known under the name fried-egg (fried eggs, fried eggs) growing into the environment; they differ in polymorphism, consist of branchy, chained, spherical individuals of different optical density and the smallest reproduced individuals of 100 in size — 450 nanometers. Reproduction happens budding, segmentation of branchy and chained forms, division. The cytoplasmic membrane of the mycoplasmas and ureaplasmas entering into this family differs biol, activity; it carries out the major fiziol, functions, reception of toxins, generation of energy, regulation of intracellular metabolism, is responsible for a translocation of substrates in a cell, specific and standard antigenic specificity, adsorption on a membrane of erythrocytes, spermatozoa, epithelial cells, etc.

For specific differentiation of representatives of M. use definition of glycoclastic, arginindezaminazny, ureazny and nukleazny activity, edges it is not identical at different types. Also specific differences on a homology nucleinic to - to t, content of guanine and a tsitozin, electrophoretic mobility of proteins and lipids, abilities of hemadsorption, hemagglutination and hemolysis of erythrocytes of a different origin are noted. Antigenic distinctions depend on the chemical nature of separate antigenic components and on their localization in a cytoplasmic membrane. So, M. have pneumoniae, M. of neurolyticum and nek-ry types of ureaplasmas serological active antigenic components are presented fosfo-and the glycerolipids which are located on a surface layer of a cytoplasmic membrane; at M. active antigenic fractions are connected by hominis with the phosphatidylglycerin located in the depth of a mebranny matrix, and at Acholeplasma laidlawii (the representative of the Acholeplasmataceae family) — with the glycolipids and glycoproteins localized on internal and outside surfaces of membranes.

Mycoplasmas unlike akholeplazm are sensitive to digitonin, Amphotericinum In, polyp-propenyl anisole-sodium sulphonate.

Pathogenicity of mycoplasmas can be caused by toxicogenic functions, the adsorptive capacity and nature of relationship with cells of the owner, and also enzymatic activity.

The mycoplasmas forming ekzo-and endotoxins are known. So, M. neurolyticum produces the exotoxin which is protein with a molecular weight of 200 000, quickly attached to astrocytes of a brain; The M of gallisepticum also produces exotoxin of neurogenic action, M. of mycoides subsp. mycoides et subsp. capri produce the endotoxic substances known under the name of galactan and glucan.

Interaction of mycoplasmas and cells of the owner is caused by their adsorption on a surface of cells and implementation of membrane and other components of mycoplasmas in a cell. As a result can develop acute, hron, or the latent mycoplasmal infection of cells, edges in case of an acute infection is shown in destruction of cells, and in a case hron, or latent infection — in change of barrier and regulatory functions of a membrane of cells of the owner, i.e. transformation of the last in immunological alien [G. J. McGarrity 1978]. In this case mycoplasmas initiate immunopato l. frustration. The latent mycoplasmal infection of cells can influence the chromosomal device of cells, causing various patol, changes.

Numerous fermental systems of mycoplasmas (a nuclease, an argininedeaminase, acid phosphatases, ureases, lactate dehydrogenases, a neuraminidase, etc.) are considered as factors of pathogenicity. So, damages of cells can be result of splitting of arginine of an arginindezaminazama of mycoplasmas of a nukleozidfosforilaz of mycoplasmas; causing destruction of cellular thymidine, suppresses normal cell fission; the neuraminidase (A. pneumoniae, M. of gallisepticum) causes adsorption of mycoplasmas on a surface of erythrocytes or cells of an epithelium of a respiratory path, causing their damage; features of energy balance (M. of pneumoniae, M. of pulmonis, etc.) lead to formation of H 2 O 2 , causing hemolysis of erythrocytes of a ram and Guinea pigs, and also damage of a tracheal and bronchial epithelium.

Mycoplasmas depending on localization caused by them patol, processes it is possible to differentiate on: mycoplasmas — causative agents of respiratory diseases; the mycoplasmas connected with diseases of secretory system, reproductive organs and mammary glands; mycoplasmas — possible causative agents of arthritises; mycoplasmas — possible activators of difficult inflammatory syndromes; the mycoplasmas causing immunopato l. frustration and playing a part in a pathogeny of viral leukoses. The diseases caused by mycoplasmas or which are associated with them are often called mycoplasmoses.

Carry to so-called respiratory mycoplasmoses: contagious pleuropneumonia large and small cattle (M. mycoides subsp. mycoides and subsp. capri), pneumonia of a cattle (M. of arginini, M. of bovirhinis, M. of dispar, A. modicum, Ureaplasma), pneumonia of sheep (M. ovipneumoniae), pigs (M. of hyopneumoniae, M. suipneumoniae), bronchial pneumonia and a bronchietasia of rats and mice (M. pulmonis), acute and hron, respiratory diseases of hens and turkeys (M. of gallisepticum, M. meleagridis), primary atypical pneumonia and acute respiratory diseases of the person (M. pneumoniae which is earlier described under the name «agent of Eton»), pharyngitises and ORZ of the person (M. hominis).

Carry to diseases of the reproductive organs which are associated with mycoplasmas: vulvovaginitis, mastitis, defeats of seed plants (M. bovigenitalium), endometritises, salpingo-oophorites (M. agalactiae subsp. bovis), experimental mastitis (Ureaplasma) at cattle; mastitis of sheep and goats (M. agalactiae subsp. agalactiae); hron, inflammatory processes of the urogenital sphere of the person, pathology of pregnancy and fruit, infertilnost of men, pyelonephritises (M. of hominis, U. urealyticum) person.

The diseases of joints connected with a mycoplasmal infection proceed as acute purulent inflammatory processes and hron, not purulent, having certain lines of looking alike a pseudorheumatism of the person. So, M. agalactiae subsp. bovis and M. mycoides subsp. mycoides (a vaccinal strain) cause damages to fibers and the capsule of synovial fabric at cattle. At goats and sheep the purulent and not purulent injuries of joints and periartikulyarny fabric caused by M. arginini and M. agalactiae subsp are described. agalactiae. At M.'s pigs of hyosynoviae and especially M. hyorhinis induce the defeats similar to a pseudorheumatism at the person. The m of arthritidis causes acute and hron, purulent arthritises of mice and rats. At the person at a pseudorheumatism from synovial fluid and fabric M. are allocated to fermentans and M. to arthritidis, a role to-rykh in a pathogeny of this disease and others immunopatol. frustration is a subject of active studying.

See also Mycoplasmal infections , Mollicutes .


Bibliography: Timakov V. D. and Kagan G. Ya. L-forms of bacteria and the Mycoplasmataceae family in pathology, M., 1973, bibliogr.; Mycoplasma infection in cell cultures, ed. by G. J. McGarrity a. o., N.Y. — L., 1978; The mycoplasmas ed. by M. F. Barile a. o., N. Y., 1979.


G. Ya. Kagan.

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