Colonial opacity variation in Mycoplasma pulmonis

Liss, Alan; Heiland, R A

doi:10.1128/iai.41.3.1245-1251.1983

Cited by 6 publications

(4 citation statements)

References 14 publications

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“…These studies address the considerable variation seen in previous studies concerning mycoplasmal virulence factors. Various investigators have suggested a relationship between the colony opacity (19), hemadsorption (2,12), hemolysis (2, 12), or nonspecific mitogenicity (2,4,12) and virulence. Other authors have questioned these relationships (2, 12).…”

Section: Discussionmentioning

confidence: 99%

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Colony opacity, hemadsorption, hemolysis, and mitogenicity are not associated with virulence of Mycoplasma pulmonis

et al. 1988

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Colony opacity, hemadsorption and hemolysis of erythrocytes, and the ability of whole mycoplasmal cells to induce a blastogenic response when incubated with C3H/HeN or C57BL/6 mouse lymphocytes were examined for 18 strains of Mycoplasma pulmonis to determine if any of these characteristics could be associated with virulence in vivo. Although there were differences among strains in each of these characteristics, none of these parameters were associated with virulence. Mycoplasma pulmonis infection is a useful model of respiratory mycoplasmosis in mammalian species (1, 2, 17) and is an important naturally occurring disease of rodents (2, 3, 5, 16, 18). Virulence factors of mycoplasmas are poorly understood (2, 12). Most of the work has been done on Mycoplasma pneumoniae (2), a human pathogen, and it has been well documented that M. pulmonis does not have some of the same factors that seem to be important in M. pneumoniae disease (2, 12). Various investigators have postulated that several characteristics, including hemolysis (2, 12), hemadsorption (2, 12, 20), the amount of colony opacity (19), and nonspecific mitogenicity (2, 4, 12) could play a role in the virulence of M. pulmonis. A total of 18 strains of M. pulmonis that had been tested for virulence in pathogen-free C3H/HeN mice were tested for each of the above characteristics to see if they were associated with virulence. Strains Ml and UAB CT were virulent, as they readily established infections and produced gross lung lesions in mice. Strains UAB 5782C, UAB 6510, UAB 8145D, UAB T, 66, Peter C, Nelson C, and Negroni established infections but did not produce gross lung lesions and were thus considered infective but relatively avirulent. The other eight strains were not recoverable from the mice at 14 days postinoculation and were considered avirulent (8). Although the present studies did not show statistical correlations between colony opacity, hemadsorption, hemolysis, or mitogenicity and either virulence or ability to infect mice, they did suggest certain relationships between these parameters and the study of mycoplasmal virulence when considered in conjunction with previous studies involving these same strains of M. pulmonis. MATERIALS AND METHODS Mycoplasmas. The strains of M. pulmonis used in these studies were UAB 5782C, UAB 6510, UAB 8145D, UAB T,

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Section: Discussionmentioning

confidence: 99%

“…Colony opacity. All mycoplasmal strains were grown on agar and observed at 3, 7, and 10 days, as described by Liss and Heiland (19). All strains were tested in duplicate at concentrations of 101, 102, and 103 CFU.…”

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confidence: 99%

Colony opacity, hemadsorption, hemolysis, and mitogenicity are not associated with virulence of Mycoplasma pulmonis

et al. 1988

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“…Colonial phenotypes, indicative of cell-to-cell association, have been valuable in identifying a variety of cell mutants in eubacteria and mycoplasmas (e.g. Liss & Heiland, 1983). Colonial morphologies were found to be affected by the viral phase.…”

Section: Discussionmentioning

confidence: 99%

Acholeplasma laidlawii Cells Acutely and Chronically Infected with Group 1 Acholeplasmavirus

Liss

Ritter

1985

Microbiology

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Interactions between group 1 acholeplasmaviruses and their host cells were studied. Acutely infected, chronically infected and uninfected cultures of Acholeplasma laidlawii strain JA1 were compared by their growth in broth and on agar, by the sensitivities of the uninfected and chronically infected cells to representatives of each of the three groups of acholeplasmaviruses, and by their SDS-PAGE polypeptide profiles. Acutely infected cells resembled uninfected cells by these criteria, except for the fact that progeny virus was being released. Two types of chronically infected cells were found:rapid growers (the same doubling time as uninfected cells) and slow growers. The latter resembled uninfected cells, except for their slower growth and low-level release of virus, and the former was resistant to group 1 viruses and had a unique polypeptide profile. These biological characterizations help to establish the non-lytic, non-cytocidal cycle of the group 1 acholeplasmaviruses.

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“…1982;Taylor ef al.. 1988) and that a high mutation rate may occur within this group of organisms (Woese et at., 1985). Marked phenotypic and antigenic variation also occurs within several Mycoplasma species (G. Christiansen ef at., 1987;Liss and Heiland, 1983;Watson ef a/., 1988) including Mycoptasma hyorhinis (Gois etat., 1974;Boyerand Wise. 1989).…”

Section: Introductionmentioning

confidence: 99%

A Mycoplasma genetic element resembling prokaryotic insertion sequences

Ferrell

Heidari

Wise

et al. 1989

Molecular Microbiology

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Nucleotide sequence analysis of two Mycoplasma hyopneumoniae-derived copies of a repetitive genetic element revealed structural similarities to typical prokaryotic insertion sequences. This is the first such sequence identified in the class Mollicutes. The element spans approximately 1550bp, with 28bp inverted terminal repeats. Two open reading frames occur within the sequence, one potentially encoding a protein with a size-variant alpha-helical domain containing heptameric leucine periodicity. Hybridization data with several strains from each of two mycoplasma species showed that the repetitive sequence is variably distributed within the M. hyopneumoniae and Mycoplasma hyorhinis chromosomes and indicated that in some cases the repeated sequence is contained within a larger genetic element which may be the result of phage or plasmid insertion.

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Colonial opacity variation in Mycoplasma pulmonis

Cited by 6 publications

References 14 publications

Colony opacity, hemadsorption, hemolysis, and mitogenicity are not associated with virulence of Mycoplasma pulmonis

Colony opacity, hemadsorption, hemolysis, and mitogenicity are not associated with virulence of Mycoplasma pulmonis

Acholeplasma laidlawii Cells Acutely and Chronically Infected with Group 1 Acholeplasmavirus

A Mycoplasma genetic element resembling prokaryotic insertion sequences

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