Susceptibility of Human Mycoplasmata to Ultraviolet and X Irradiations

Furness, G.; Pipes, Florence J.; McMurtrey, Marion J.

doi:10.1093/infdis/118.1.1

Cited by 30 publications

(12 citation statements)

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“…To avoid clumping of cells and loss of cell viability, no centrifugation method was used for harvesting mycoplasma cells in broth cultures in this experiment. Mycoplasma cells were first plated on agar medium and then irradiated by UV light by a method similar to that previously reported by Furness et al (16). Although the data are not shown here, the number of colonies formed on agar plates which had been irradiated by excessive doses of UV light was identical within the experimental error range to that on unirradiated agar plates.…”

Section: Uv Survival Curvessupporting

confidence: 68%

“…1. It has been reported that the UV sensitivity of mycoplasmas is significantly affected by their growth stage (4,13,16). The data described here, therefore, are not sufficient for accuratey comparisons of UV sensitivity among five strains of human mycoplasma Caffeine has been widely used as an effective repair inhibitor since Metzger (23) found with E. coli that caffeine blocks dark reactivation of UV-irradiated cells.…”

Section: Recovery Of the Colony-forming Ability Of Uv-irradiated Cellmentioning

confidence: 80%

“…The other portion was filtered through a membrane filter of 0.65 tun pore size (Toyo TM-1) to remove clumped cells and then the filtrate was diluted as above. Irradiation of mycoplasma cells by UV light was essentially carried out according to the method previously reported by Furness et al (16). Six drops of 10 t.c.1 aliquots from each serial 10-fold dilution were plated on an agar plate in a Petri dish (9 cm in diameter).…”

Section: Methodsmentioning

confidence: 99%

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UV Survival of Human Mycoplasmas: Evidence of Dark Reactivation in Mycoplasma buccale

Aoki

Ito

Watanabe

1979

Microbiology and Immunology

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The inactivation by ultraviolet (UV) light irradiation of mycoplasma cells of five human strains was monitored by investigating the colony-forming ability. The survival curves of five strains tested indicated that the cells of Mycoplasma buccale only are single and homogenously susceptible to UV light. The effect of the repair inhibitor, caffeine, on the colony-forming ability of UV-irradiated cells was investigated with Al. buccale because of its homogenous susceptibility to UV light. The colony formation of irradiated cells was markedly depressed by post-irradiation treatment with caffeine at concentrations that had little or no effect on the colony formation of unirradiated cells. The colony-forming units (CFU) of UV-irradiated cells which were kept in broth without caffeine in the dark increased without a lag as the time in the dark increased. The colony-forming ability of the irradiated cells completely recovered after 3 hr in the dark. However, when irradiated cells were kept in the presence of caffeine, no increase in their CFU was observed. The mode of action of caffeine on UV-irradiated cells closely resembles that described for other organisms which possess dark reactivation systems for UV-induced damage in deoxyribonucleic acid (DNA). Thus, the results obtained provide evidence for the existence of a dark repair function in M. buccale.

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Section: Uv Survival Curvessupporting

confidence: 68%

Section: Recovery Of the Colony-forming Ability Of Uv-irradiated Cellmentioning

confidence: 80%

Section: Methodsmentioning

confidence: 99%

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UV Survival of Human Mycoplasmas: Evidence of Dark Reactivation in Mycoplasma buccale

Aoki

Ito

Watanabe

1979

Microbiology and Immunology

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“…Mycoplasma salivarium strain S 9 teP (ATCC 33130) was isolated from an individual with a normal oral cavity. The methods for preparing media and stock cultures and for obtaining single cell suspensions and making colony counts have been reported (Furness et al 1968;Furness 1969Furness , 1970 …”

Section: Methodsmentioning

confidence: 99%

“…Neither ultracentrifugation nor gel electrophoresis detected plasmid DNA in mycoplasma DNA preparations from mycoplasma cultures which had been enriched with 50 pg uridine/mL broth added 5 h prior to harvesting. Guerry et al (1973) reported a method for increasing the proportion of plasmid DNA in preparations of DNA from E. coli containing plasmids. These authors lysed the cells by shaking the bacteria in a solution containing 1 M NaCl and 1% sodium dodecyl sulfate.…”

Section: Agarose Gel Electrophoresismentioning

confidence: 99%

Attempts to detect by physicochemical methods plasmid DNA in mycoplasmas of human origin before and after transformation to tetracycline resistance

Saha¹,

Cerone²,

Furness³

1982

Can. J. Microbiol.

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Physicochemical methods have been used to compare mycoplasma DNA capable of the genetic transformation of tetracycline resistance with DNA from tetracycline-sensitive mycoplasmas and their transformants. These mycoplasmas were isolated from human patients. The DNA extracted from Mycoplasma hominis tetr resistant to 100 microgram/mL tetracycline transforms tetracycline resistance to sensitive strains of Mycoplasma salivarium tets and Mycoplasma hominis tets but not Mycoplasma fermentans tets. Bulk DNA and DNA extracted by methods which increase the yield of circular DNA moieties were analyzed by cesium chloride and cesium chloride--ethidium bromide buoyant density ultracentrifugation and by horizontal and vertical agarose gel electrophoresis. Extrachromosomal DNA was not detected, which suggests that transformation was mediated by the recombination of chromosomal genes for tetracycline resistance and not by R factors. Moreover, no significant differences were detected in the DNA from the resistant and sensitive species or from their transformants and Mycoplasma fermentans tets which could not be transformed to resistance to 10 micrograms tetracycline/mL medium.

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