STORAGE OF MYCOPLASMA STRAINS

Abstract

Kelton, William H. (National Animal Disease Laboratory, Ames, Iowa). Storage of Mycoplasma strains. J. Bacteriol. 87: 588–592. 1964.—Survival of Mycoplasma strains (19 of avian origin, 3 human, 3 canine, and 1 saprophyte) in the lyophilized state and at various storage temperatures was studied. The effect of alternate freezing and thawing was also studied. All strains survived the freeze-drying process and at least 3 or 4 years of storage in the lyophilized state. At −26 C, they survived for at least 10 months, but changes were noted in colony size and growth rate of cultures stored longer than 10 months. At −65 C, however, there was little loss in viable numbers from 12 months of storage, and no changes in the organisms were apparent. There was considerable variation from strain to strain in resistance to alternate freezing and thawing. Of 16 strains tested, 13 withstood the freezing and thawing better than did the bacterium Escherichia coli . At 5 C, again, there was considerable variation in survival between strains. The saprophytic strain, C-15, showed no apparent loss after 9 weeks at 5 C. Most other strains showed rather rapid loss of viable numbers when stored at 5 C.

Survival of Frozen Mycoplasmas

“…The ability to recover viable mycoplasmas from frozen cultures makes possible the preservation of stock cultures by frozen storage and the provision of readily available standard inocula for physiological studies (1,5,6,14). Yet, until now no detailed investigation has been made of the factors affecting the survival of mycoplasmas during the freezing process and the following storage in the frozen state.…”

Preservation Evaluation of Mycoplasma fermentans in Different Conditions

“…With respect to the two temperature ranges that were used, there was no marked variation, favoring the viability of Mycoplasma fermentans P140 and PG18 during the twelve months of the test, evidencing by means of the culture in SP4 agar with a characteristic colonial growth of mycoplasmas with considerable diameters and abundant growth, as was the case with Mycoplasma fermentans P140 ( Figure 2 panel A and B) and Mycoplasma fermentans PG18 (Figure 2 panel D). Regarding the effect on the variation in the colonial growth of Mycoplasma fermentans P140 and PG18, this behavior is related to the absence of cell wall that characterizes mycoplasmas, an effect that has been reported in other work (Kelton, 1964) and given the diversity intraspecific of the microorganisms, it has been established that not all strains of the same species respond equally to the selection of tests applied to them (24,25).…”

“…It has been reported that variations in conservation temperature and that the freezing and thawing process induce changes in the growth and size of mycoplasma colonies (8). An investigation evaluated the viability of mycoplasma cultures of animal origin during periods of two years at different freezing temperatures and in the lyophilized phase, finding that their viability was favored, but involved more infrastructure and high operating costs, highlighting that there are various reports that study the protocols to maintain the viability of mycoplasmas, the frequently described species being of veterinary interest (9-12).…”

Effects of Storage Time and Thawing Methods on the Recovery of Mycoplasma Species in Milk Samples from Cows with Intramammary Infections

“…Little work has been done in examining the viability of mycoplasma species. In observing avian, human, canine, and saprophytic types of mycoplasma, Kelton (1964) found considerable variation between strains in Original milk sample collected from cows at weekly intervals. A sample was collected from each mammary quarter and a composite sample was collected.…”