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Query: UMLS:C0026936 (Mycoplasma)
 14,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A static ampoule microcalorimeter was used to study the growth of mycoplasmas, acholeplasmas and ureaplasmas. Growth as indicated by thermograms was compared with the results of conventional methods, namely, terminal dilution counts, plate counts, turbidimetric measurements, glucose consumption and pH changes. Removal of oxygen had little effect on mycoplasma growth. The microcalorimetric method is potentially useful for identifying and enumerating the members of the Mycoplasmatales.
J Gen Microbiol 1976 Oct
PMID:Microcalorimetric detection of growth of Mycoplasmatales. 1 Dec 73

The morphology of Ureaplasm urealyticum in broth cultures was studied by phase-contrast microscopy. Most organisms appeared singly or in pairs. Long filaments and long chains of cocci, common in classical mycoplasma cultures, were not observed. On solid medium, U. urealyticum produced "fried-egg" colonies which developed according to the scheme suggested by Razin and Oliver (J. Gen. Microbiol., 1961) for the morphogenesis of the classical mycoplasma colonies. The formation of the peripheral zone of the colonies followed that of the central zone only when growth conditions were adequate, Hence, the appearance of peripheral zones, and consequently the larger colony size, can be taken as an indicator of improved growth conditions. Incubation in an atmosphere of 100% CO2 resulted in significantly larger colonies than in an atmosphere of N2, O2, or air. CO2 acts as a buffer, keeping the pH at the optimal range for Ureaplasma growth (pH 6.0 to 6.5) in the presence of the ammonia produced from the urea hydrolyzed by the organisms. The addition to the medium of 0.01 M urea together with 0.01 M putrescine enabled better growth than with urea alone. Small amounts of phosphate improved growth in an atmosphere of CO2, apparently fulfilling a nutritional role. Under nitrogen, higher phosphate concentrations were required for good growth, apparently serving as a buffer as well as a nutrient. Sodium chloride and sucrose which had been added to increase the tonicity of the medium inhibited growth above 0.1 M. An increase in the agar concentration above 2% resulted in decreased colony size. Likewise, prolonged drying of the agar plates caused a marked decrease in colony size, mostly affecting the peripheral zone. The addition of both urea and putrescine to the growth medium and incubation in a humidified CO2 atmosphere are recommended for improved growth and formation of fried-egg colonies of U. ureaplyticum on agar. It must be emphasized that these experiments were carried out with a laboratory-adapted strain.
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PMID:Morphology of Ureaplasma urealyticum (T-mycoplasma) organisms and colonies. 1 86

Attachment of washed Mycoplasma gallisepticum cells to glass was quantified with organisms in which membrane lipids were labelled with 3H. Siliconization of the test tubes decreased attachment, while centrifugation increased it. Attachment increased with temperature, decreased with increasing pH and ionic strength of the attachment mixture, but was unaffected by Ca2+, Mg2+ and EDTA. This suggests that ionic bonds, but not salt bridges, participate in the attachment process. Glycophorin, the major receptor responsible for M. gallisepticum attachment to erythrocytes, partially inhibited the attachment of the organisms to glass. However, bovine serum albumin also decreased attachment. Extensive pretreatment of the organisms with trypsin decreased their ability to attach to glass by about 35 to 40%. Trypsin and pronase failed to detach the organisms already bound to glass, suggesting that external mycoplasma cell components, other than membrane proteins, also participate in attachment of the organisms to glass.
J Gen Microbiol 1979 Mar
PMID:Adherence of Mycoplasma gallisepticum to glass. 3 84

Cultures of Acholeplasma laidlawii strain M1305/68 were inoculated with Mycoplasmatales virus-laidlawii 3 (MV-L3) and examined by electron microscopy. Particles resembling MV-L3 were observed both intra- and extracellularly in thin sections prepared from MV-L3 infected cultures, but not from uninfected cultures. Similar particles were occasionally observed in uninoculated cultures of A. laidlawii strain BN1 cells, from which a virus (BN1 virus) was subsequently isolated. This virus was morphologically similar but not identical to MV-L3. It also differed serologically from, and in its resistance to, MV-L3 and the other mycoplasma viruses.
J Gen Virol 1979 Feb
PMID:Demonstration by electron microscopy of intracellular virus in Acholeplasma laidlawii infected with either MV-L3 or a similar but serologically distinct virus (BN1 virus). 8 56

Mycoplasma mycoides subsp. mycoides (PG1 and strain Y) proteins were solubilized in Triton X-100, and the antigenic proteins were precipitated from this complex mixture by addition of antiserum and then separated by two-dimensional gel electrophoresis. Of the 300 proteins solubilized, about 10 were precipitated. Proteins of PG1, a slow-growing, small colony (SC) strain, were precipitated by antiserum to PG1 and by antiserum to strain Y, a fast-growing, large colony (LC) strain. Similarly, strain Y proteins were precipitated by antiserum to PG1 and by antiserum to strain Y. The few proteins precipitated in this way gave similar patterns after two-dimensional gel electrophoresis indicating that many of the dominant protein antigens of PG1 and strain Y are shared. Antiserum to Mycoplasma mycoides subsp. capri (PG3) also precipitated some proteins of strain Y. Antiserum to Mycoplasma gallisepticum gave no reaction with any M. mycoides antigens. It was concluded that, in addition to the polysaccharide antigens, there are proteins in M. mycoides that are antigenic and that some of these are found in both the SC and LC strains of subsp. mycoides and also in subsp. capri.
J Gen Microbiol 1979 Nov
PMID:Immunoprecipitation of Triton X-100-solubilized Mycoplasma mycoides proteins. 9 14

The replication of human cytomegalovirus (CMV) and herpes simplex virus (HSV) was studied in three human embryo cell lines (CMV-Mj-HEL-I, CMV-Mj-HEL-2, and CMV-Mj-HEL-2,T-I) transformed in vitro by human CMV. Growth studies revealed that these cells were completely resistant to infection by CMV strains ADI69 and Mj and partially resistant to HSV types I and 2. Neither virus DNA nor virus proteins were synthesized in the transformed cells infected with CMV AD169. The HSV production in CMV-transformed human embryo lung (HEL) cells was delayed when compared to the virus production in normal HEL cells and spread of HSV c.p.e. was slower in the transformed cells. The treatment of normal HEL cells with a crude extract of CMV-transformed HEL cells also resulted in inhibition of the spread of c.p.e. of HSV types I and 2. The inhibitory effect was not due to interferon since vesicular stomatitis virus replication was not affected and several experiments showed that it was not due to mycoplasma. The presence of virus inhibitor molecules in CMV-transformed cells absent in normal HEL cells is postulated.
J Gen Virol 1978 Aug
PMID:Replication of herpesviruses in human cells transformed by cytomegalovirus. 21 Nov 87

The effect of pneumonia induced by Mycoplasma pulmonis in mice on the resistance of the lung to additional bacterial infection was examined. The effect of pneumonia induced by Sendai virus on the resistance of mice to M. pulmonis was also investigated and compared with the effect of Sendai virus on resistance to Staphylococcus aureus. Sendai virus infection decreased subsequent resistance to M. pulmonis in proportion to the virus dose. Decreased resistance to subsequent S. aureus and M. pulmonis infection was greatest at about the same time after inoculation of virus and was related to virus-induced lesions. Besides affecting the resistance of mice to subsequent mycoplasma infection, Sendai virus could enhance an existing mycoplasma infection. Pneumonia induced by M. pulmonis did not decrease resistance to subsequent bacterial infection. The mechanism whereby Sendai virus decreases host resistance is therefore similar for bacteria and mycoplasmas, but pneumonia induced by mycoplasmas does not have the same effect.
J Gen Microbiol 1978 Nov
PMID:The effect of pneumonia induced in mice with Mycoplasma pulmonis on resistance to subsequent bacterial infection and the effect of a respiratory infection with Sendai virus on the resistance of mice to Mycoplasma pulmonis. 21 2

The virulence of five strains of Mycoplasma pulmonis, as judged by their ability to survive in the respiratory tract and induce pneumonia in CBA mice, was related to the ability of viable organisms to persist in the peritoneal cavity. This appeared to be the result of differences in the ability of the strains to resist killing by peritoneal macrophages in vivo. It is suggested that resistance to phagocytosis by macrophages is an important determinant of virulence for M. pulmonis.
J Gen Microbiol 1979 Oct
PMID:Variation in the virulence of strains of Mycoplasma pulmonis related to susceptibility to killing by macrophages in vivo. 23 25

Polyacrylamide gel electrophoresis and isoelectric focusing techniques have been used to compare NAD-dependent L(plus) lactate dehydrogenases (LDH) from ten different strains of Mycoplasma mycoides var. mycoides. The enzymes were not distinguished from one another, or from normal bovine LDH 1 by these methods. The kinetic behaviour of LDH form M. mycoides (T1 vaccine strain) suggested that the enzyme could readily reduce pyruvate or oxidize lactate in a manner which, in vertebrates, requires two different isoenzymes.
J Gen Microbiol 1975 May
PMID:Studies of lactate dehydrogenase of Mycoplasma mycoides var. mycoides. 23 91

Strains of Mycoplasma mycoides subsp. mycoides have been divided into small colony (SC) and large colony (LC) types (Cottew & Yeats, 1978). The protein patterns of representative strains of these two types and of M. mycoides subsp. capri were compared by a high resolution, two-dimensional gel electrophoretic method. The results suggest that the LC strains are more closely related to M. mycoides subsp. capri than to the SC strains of M. mycoides subsp. mycoides.
J Gen Microbiol 1978 Dec
PMID:Relationships between strains of Mycoplasma mycoides subspp. mycoides and capri studied by two-dimensional gel electrophoresis of cell proteins. 37 Mar 43


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