RECOVERY, IDENTIFICATION, AND NEUROTOXICITY OF SABIN'S TYPE A AND C MOUSE MYCOPLASMA (PPLO) FROM LYOPHILIZED CULTURES

Correlation of mollicutes and their viruses with multiple sclerosis and other demyelinating diseases

To identify infectious diseases likely involved in MS, the author previously correlated the geographical distribution of MS with the global distribution of tick-borne diseases. Tick-borne infectious agents include mollicutes or mycoplasmas. The current paper reviews evidence that mollicutes, especially spiroplasmas, or their viruses could be the initial exposure that causes MS. Mollicute infections, including the effects of their toxins, can be treated or prevented with gold salts or tetracyclines. If further research recommended by this review finds a role of mycoplasmas in MS, treatment of MS with gold with tetracycline should be evaluated.

Chronic proliferative arthritis of mice induced by Mycoplasma arthritidis. I. Induction of disease and histopathological characteristics

Mice injected intravenously with Mycoplasma arthritidis developed a chronic arthritis which persisted through at least 269 days. Rats similarly treated developed an acute short-term infection. The mouse disease was characterized by periods of remission and exacerbation and was proliferative in nature, gradually spreading to adjacent joints. M. arthritidis strain 158 P10 was found to be less arthritogenic for mice than for rats, but further passage of this strain in mice substantially increased its virulence. Unlike rats, mice appeared to be susceptible to a "toxin" of M. arthritidis and they developed a necrotic spreading abscess after subcutaneous administration of the organisms. Histopathological studies revealed that mice varied greatly in the degree of joint inflammation, destruction, and repair. The disease was characterized by (i) an initial acute phase with infiltration of the articular and periarticular tissues with polymorphonuclear leukocytes and a mild hyperplasia of the synovial membrane; (ii) a mixed acute-chronic phase in which new areas of acute inflammation developed alongside areas of chronic lesions; (iii) a chronic phase followed which was characterized by massive synovial proliferation with mononuclear cell infiltration, irregularity in the articulating cartilage, pannus formation, and "punched out" defects in cortical bone near cartilagenous osseous junctures. The clinical course and histopathological characteristics of the chronic phase of mouse arthritis induced by M. arthritidis closely resembled those of rheumatoid arthritis of man.

Preservation of Mycoplasma strains by freezing in liquid nitrogen and by lyophilization with sucrose

Procedures for maintaining Mycoplasma strains are described. Liquid nitrogen storage provided an adequate means for keeping stock cultures stable. Over 74 strains of approximately 26 species have been preserved in this way, some for as long as 9 years. Mycoplasma strains can also be recovered satisfactorily from the freeze-dried state when the procedure described includes the use of 12% (v/v) sucrose as an additive. Fifteen strains representing 12 or more species were subjected to a freeze-drying program with and without sucrose added to concentrated cell suspensions in growth medium. Cell counts indicate improved survival with sucrose.

Deoxyribonucleic acid base compositions of selected mycoplasmas and L-phase variants

Deoxyribonucleic acid base compositions were determined for 25 Mycoplasma strains and 6 L-phase variant strains. Values obtained correlated well with the results of other investigators.

Serological comparison of ten glycolytic Mycoplasma species

Seventeen strains of mycoplasmata representing 11 named species were compared serologically by three parameters: growth inhibition on agar, double immunodiffusion, and complement fixation. In growth-inhibition studies, a strain labeled Mycoplasma histotropicum was found related to and perhaps best classified as M. pulmonis, a relationship confirmed by double immuno-diffusion studies. A comparison of the remaining 10 species demonstrated that two pairs of species could be shown to be closely related by complement fixation and double immunodiffusion but not by growth inhibition; these were: M. granularum-M. laidlawii and M. felis-M. canis. M. pneumoniae and M. gallisepticum were the most serologically unique organisms in this study, showing very few cross-reactions with each other or other species. Overall, taxonomic groupings obtained by comparative serology appeared to correlate with the groupings obtained when the guanine plus cytosine contents of the deoxyribonucleic acid of mycoplasmata were employed as classification criteria. The group of organisms having a guanine plus cytosine content of 23 to 28% (M. canis, M. fermentans, M. hyorhinis, M. neurolyticum, and M. pulmonis) appeared to be generally serologically related. Thus the remarkable heterogeneity observed in the base composition of the deoxyribonucleic acid of order Mycoplasmatales is also reflected and apparently paralleled by a corresponding serological heterogeneity.

Mycoplasma taxonomy studiedy electrophoresis of cell proteins

The electrophoretic patterns of cell proteins in polyacrylamide gels were used for the study of several taxonomic problems in the Mycoplasmatales. The patterns of five Mycoplasma hominis strains showed marked differences that corresponded with their known serological and nucleic acid heterogeneity. The patterns of three M. mycoides var. mycoides strains isolated in different countries were essentially identical. The electrophoretic patterns of several caprine strains resembled those of M. mycoides var. mycoides, supporting their classification as M. mycoides var. capri. Strain B3, a swine isolate, accordingly was tentatively identified as M. mycoides var. capri. The bovine mastitis strain M. agalactiae var. bovis possessed a pattern basically similar to that of the goat mastitis strain M. agalactiae, supporting the inclusion of both strains in one species. Three M. pulmonis strains isolated from rats or tissue cultures showed nearly identical patterns. The pattern of the toxigenic M. neurolyticum (Sabin A) strain resembled but was not identical with that of the nontoxigenic PG28 strain. The avian Mycoplasma species, M. gallisepticum, M. meleagridis, M. synoviae, M. gallinarum, and M. iners showed easily distinguishable and specific patterns, supporting their present classification in different species. Several improvements in the electrophoretic technique are described, and its advantages and limitations as a taxonomic tool are discussed.

PRODUCTION AND BIOLOGICAL CHARACTERISTICS OF AN EXTRACELLULAR NEUROTOXIN FROM MYCOPLASMA NEUROLYTICUM

Tully, Joseph G. (National Institute of Allergy and Infectious Diseases, Bethesda, Md.). Production and biological characteristics of an extracellular neurotoxin from Mycoplasma neurolyticum . J. Bacteriol. 88: 381–388. 1964.—Toxigenic strains of Mycoplasma neurolyticum were found to produce a potent extracellular neurotoxin for mice under a variety of cultural conditions. The observed biological characteristics of this toxin were quite similar to those originally described by Sabin. The toxin was again found to be readily inactivated by prolonged incubation and, when separated from Mycoplasma cells by filtration, possessed a greater heat resistance than whole cells. Young mice and rats were generally susceptible to neurotoxin, whereas most other experimental animals were resistant. Filtration results confirmed a minimal reproductive unit of 125 to 200 mμ for two neurotoxic Mycoplasma strains, with both cell-free filtrates reproducing the rolling disease syndrome in mice. Twice-washed Mycoplasma cells were also observed to be as neurotoxic as filtrates. Plate counting results revealed an intravenous ld 50 of approximately 3 × 10 8 washed cells for young mice.