Theodor Rosebury

Isolation and Pure Cultivation of the Smaller Mouth Spirochetes by an Improved Method

Summary Details are given of a method for primary anaerobic cultivation in small plates of spirochetes from human and experimental fuso-spirochetal exudates, and for their pure subculture in plates and tubes. Successful primary plates were obtained in 23 instances out of 29 cases of human infection, and from all of 21 experimentally infected guinea pigs. Eleven strains of spirochetes have been isolated and subcultured in a short period with little difficulty.

Susceptibility to Dental Caries in the Rat VIII. Further Studies of the Influence of Vitamin d aNd of Fats and Fatty Oils

In a previous report (18) we recorded the finding that the incidence of fissure caries produced in rats by feeding a diet containing coarsely ground rice was reduced to a significant degree by adding either corn oil or oily preparations of vitamin D to the diet. The present report deals with an attempt to determine whether the observed effect of the vitamin D preparations on caries was due to their contained oil, and with a study of the effects on caries of oils and fats other than corn oil.

The role of infection in periodontal disease

Abstract There is found in periodontal disease a characteristic and highly complex microflora which appears to represent an overgrowth of microorganisms found in the healthy mouth. This so-called fusospirochetal flora contains many microorganisms in addition to fusiform bacilli and spirochetes. The fusospirochetal flora is capable when injected parenterally of initiating a consistent, transmissible experimental infection in which the characteristic microorganisms per sist. This infection may be benign or fatal depending in part on dosage, and may entail massive invasion of viable tissue by spirochetes. In its microscopic appearance and in its experimental infectivity the fusospirochetal flora appears to be essentially similar in the different clinical entities of periodontal disease. Earlier reports that this flora is constituted by four species of anaerobes have not been confirmed. We have been able to isolate a range of microorganisms that seem to represent the whole flora, all in pure culture except for spirochetes, which were free from other bacteria but may have represented more than one spirochetal species. The dosage of fusospirochetal exudate for guinea pig infection and death has been measured and the proportions of its component morphological groups of microorganisms estimated. Evidence has been obtained that neither viruses nor other forms uncultivable in vitro are members of the fusospirochetal flora. In one exudate passage “strain” at least seventeen apparently distinct varieties of microorganisms were obtained in cultures. These organisms could be grown together in mixed culture through at least ten culture transfers, the mixture retaining its pathogenicity undiminished, but when separated and recombined, pathogenicity was lost.

Studies, in the Rat, of Susceptibility to Dental Caries: II. Effects on Teeth, in Mothers and Young, of Diets Deficient in Calcium and Vitamin D, During Pregnancy, Lactation, and Rearing

In the first report in this series (20), it was noted that enamel hypoplasia occurred in incisors of rats on a low-Ca vitamin-D-free diet, but that apparently only recently formed enamel was affected, molar teeth escaping the deformity. The emphasis placed by Mellanby (15) on possible relationships of enamel defects to dental caries suggested the desirability of attempting to produce defective molar-enamel in rats by dietary means. Since enamel calcification of rat molars is complete at a very early age, it appeared desirable to feed a deficient diet to mothers during pregnancy and lactation, and then to continue the young under the same dietary conditions. Dental effects of this and other conditions, embodying possible factors in caries etiology, form the basis of the present report.

A Preliminary Report on the Relation of Dental Aciduric Bacteria To Lactobacillus Acidophilus

Twenty-one strains of aciduric bacteria isolated from teeth, and nine strains of known Lactobacillus acidophilus, have been studied comparatively in their morphological, biochemical, and serological relations. The dental strains were isolated from the mouths of an unselected group of clinic patients of the School of Dental and Oral Surgery of Columbia University. Inoculations were made into 1 percent glucose meat infusion broth, pH 5.0, and the cultures incubated 48-72 hours at 370C. All cultures showing Gram-positive rods were streaked on casein digest agar and incubated 48 hours. Typical, faint, punctiform colonies were then transferred back into pH 5.0 broth. Three or four platings were necessary in some cases to obtain pure cultures. Nine strains of known L. acidophilus of the intestinal type were obtained from several sources as pure cultures. These, and the 21 pure cultures of dental aciduric organisms, were kept growing uniformly in casein digest broth throughout the course of the work. No consistent difference could be discovered between the groups in any part of this study. On the whole there was indication of a slightly greater homogeneity in the intestinal group than in the dental group. This was, perhaps, to be expected from the conditions under which the two groups were obtained. The appearance of the growth in broth was found to depend more on the age and extent of the growth than on any intrinsic difference in growth tendency between the groups. All of the strains showed uniform turbidity in the broth at the first appearance of growth; most of the strains of both groups

Effects of storage in CO2-ice on the viability of spirochetes and other anaerobic microorganisms isolated from the human mouth☆

Abstract Freezing and storage in solid CO 2 was effective in most instances in preserving the viability of cultures of spirochetes, anaerobic bacteria, and other organisms derived from the human mouth, over periods ranging from five to twenty months. Failure of certain subcultures seemed attributable to the cultures rather than to the method of preservation. Unpurified mixtures of these microorganisms from human lesions were maintained intact in morphology and motility by this means for the short periods required. Fusospirochetal exudates from guinea pigs remained apparently unimpaired in microscopic appearance and in infectivity for as long as thirteen months. Preservation of cultures of oral spirochetes in deep tubes of an agar medium, aerobically under paraffin oil, both at room temperature in the dark and at 37° C., was distinctly less satisfactory than preservation in CO 2 -ice.

Susceptibility to Dental Caries in the Rat: VII. Influence of Mineral Salts, Protein and Sugar, and Relationship of Calcification of Teeth and Bone1

It is apparent that several dietary factors cooperate in the production of experimental dental fissure caries in rats. The lesions are due primarily to the ingestion of particles of coarsely ground raw cereal, such as rice or corn, included in the diet from the time of weaning; but other dietary conditions influence the prevalence of caries in significant degree (7, 8, 9). This report presents the results of further studies of some of these secondary or modifying influences on caries produced with coarse rice and corn diets.