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G Furness

Publications and source records attributed to G Furness.

52 records · Page 3Linked to original sources

Binucleate classical mycoplasmas pathogenic for goats.

The growth of three pathogenic goat mycoplasmas, strains Y, KH1 and Mycoplasma mycoides var. capri (PG3), was studied. They formed classical colonies on agar containing 1/500 thallium acetate. They were inactivated during storage at 2 to 4 C and by freezing and thawing but not by shaking. Only KH1 was killed by sonic treatment. Ultraviolet inactivation curves showed that their colony-forming units were single binucleate cells. Details of their growth curves are given. Filtration through 0.45- or 0.3-mum membrane filters removed up to 97% of the cells. Less than 0.003% passed 0.22-mum membranes. In electron micrographs, the cells were seen replicating by budding and most were 0.6 to 0.9 mum in diameter; but cells between 0.1 and 0.2 mum reproduced. They usually multiplied by producing one bud, a form of binary fission. However, two buds were produced by some synchronized cells, indicating that both nuclei had divided simultaneously to form progeny, an alternate method of multiplication.

Animals↗

Differential responses of single cells and aggregates of mycoplasms to ultraviolet irradiation.

Except for Mycoplasma fermentans strain PG 18, single-cell suspensions of M. arthritidis, M. fermentans (ATCC 19989), M. hominis type 1, M. orale types 1 and 2, M. pneumoniae, and M. salivarium were inactivated exponentially by ultraviolet (UV) irradiation, in contrast to broth cultures containing clusters of elementary bodies. The susceptibility of the mycoplasmas was unaffected by storage at 2-4 C and at -70 C, by sonication, and by filtration. The rate of inactivation was dependent on the intensity of the radiations but independent of the concentration of the cells. Therefore, single-cell suspensions of these mycoplasmas could be differentiated from aggregates of cells by exponential inactivation of the colony-forming units (CFU). By this criterion, the CFU of M. arthritidis in the exponential phase of growth consisted of single cells, in contrast to the other species in which the CFU contained two or more elementary bodies. Even though the cultures of M. fermentans (PG 18) were grown from single cells, they were not homogeneous in their susceptibility to UV light. Neither were cultures of M. arthritidis and M. orale type 1 grown from single cells which had survived irradiation.

Cell Aggregation↗