The definition of mycoplasma

Mycoplasma is 1898 Nocard and so found a similar bacteria but does not have a cell wall of the prokaryotic microorganisms, can be in the absence of artificial growth and reproduction of artificial medium, diameter 50-300nm, through the bacterial filter. Formerly known as pleuropneumonia-like organism (PPLO). In 1967, It was officially named mycoplasma.

Mycoplasma: also known as mycoplasma, is currently found in the smallest of the most simple prokaryotes. The number of genes was 480. Mycoplasma cells in the only visible organelle is the ribosome (mycoplasma is a prokaryotic cell, prokaryotic cell organelles only ribosomes).

The structure of mycoplasma is relatively simple, the majority of spherical, no cell wall, only the three-layer structure of the cell membrane, it has greater variability. Mycoplasma genomes mostly double-stranded DNA, scattered throughout the cells did not form the nucleus or nucleus. This cell contains DNA, RNA and a variety of proteins, including hundreds of enzymes. Mycoplasma can be in a special culture medium on the growth, with this method with clinical diagnosis. And genitourinary tract infection is related to the decomposition of urea mycoplasma and Mycoplasma hominis two, about 20-30% of patients with non-gonococcal urethritis, is caused by the above two kinds of mycoplasma, non-gonococcal urethritis and cervix Inflammation of the second major pathogen. In the adult genitourinary tract decomposition of urea mycoplasma and mycoplasma hominis infection rate mainly related to sexual activity, that is, with the number of sexual intercourse, the number of sexual intercourse objects, regardless of both men and women are so. According to statistics, more female mycoplasma infection rate, indicating that the female reproductive tract easier to grow than the male reproductive tract mycoplasma. n addition, the decomposition of urea mycoplasma infection rate is higher than the infection rate of mycoplasma hominis.

Morphology and structure

Mycoplasma size of 0.1 ~ 0.3um, through the filter, often to the work of cell culture pollution brought about trouble. Colonies small (diameter 0.1 ~ 1.0mm), in the solid medium surface was unique "omelette" -like. No cell wall, can not maintain a fixed form and showing polymorphism, osmotic pressure sensitive to inhibition of cell wall synthesis of antibiotics is not sensitive. Gram stain is not easy to color, it is commonly used Giemsa staining dyed lavender. The content of cholesterol in cell membrane is more than 36%, which has a certain effect on maintaining the integrity of cell membrane. Cell membrane containing sterols, more than other prokaryotic membrane tenacity. Where can act on the cholesterol substances (such as amphotericin B, saponin, etc.) can cause destruction of mycoplasma membrane leaving mycoplasma death.

Mycoplasma genome is a circular to double-stranded DNA, molecular weight (only one-fifth of E. coli), synthesis and metabolism is very limited.

Mycoplasma pneumoniae at one end of a special terminal structure (terminal structure), mycoplasma can adhere to the respiratory mucosa epithelial cell surface, and pathogenicity.

Biochemical reactions and typing

Mycoplasma can generally decompose glucose can not use arginine, can use arginine can not break down glucose, which can be divided into two types of mycoplasma. Ureaplasma urealyticum can not use glucose or arginine, but can make use of urea as energy.

Mycoplasma all have a specific surface antigen structure, there is little cross-reaction, with type-specificity. Mitogen antigens were identified by growth inhibitory test (GIT) and metabolic inhibition test (MIT).

It is widely distributed in nature, there are more than 80 species. Mycoplasma associated with human mycoplasma pneumoniae (M-pneumonie, Mp), Mycoplasma hominis (UU decomposition of urea mycoplasma) and genital mycoplasma (M.genitalium, MG) and so on.

Mycoplasma pneumoniae cause pneumonia. Has been isolated from the human genitourinary tract 7 kinds of mycoplasma, which a high isolation rate and the genitourinary tract diseases, is ureaplasma urealyticum, followed by mycoplasma hominis. Mycoplasma hominis (MH), Ureaplasma urealyticum (UU) and genital mycoplasma (M.genitalium, MG) can cause urinary and reproductive tract infections.

Broadly speaking, L-type bacteria are spontaneous mutations of bacteria or antibiotics, lysozyme and other effects into a cell-wall-type strains, many of its characteristics and mycoplasma similar; strictly speaking, L-type bacteria should specifically refer to those laboratories or in the host body through the spontaneous mutation of genetic traits formed by the stability of the cell wall defect strain, and by artificial methods to the wall after the formation of the lacking cells were called protoplast (completely removed) and the spheroids (partial removal).