Characterisation of Bacteroides from sheep periodontal disease by SDS-PAGE of outer membrane proteins.

Isolates of Bacteroides species obtained from a longitudinal study of developing periodontal disease in sheep were analysed by SDS-PAGE. Protein profiles of Sarkosyl-insoluble outer membrane extracts were compared within groups of isolates which had already been defined by conventional biochemical techniques. Heterogeneity was exhibited within most groups.

A longitudinal study of the cultivable subgingival anaerobic bacteria isolated from sheep during the development of broken mouth periodontitis.

In a longitudinal bacteriological study of the cultivable subgingival anaerobic flora isolated from developing broken mouth periodontitis in sheep, samples were taken from five sheep on each of three farms on seven occasions over a period of 2.5 years. Ten different bacterial genera were isolated regularly but with fluctuating frequencies.

Preliminary study of the anaerobic bacteria isolated from subgingival plaque from sheep.

A preliminary study was made to determine the genera of cultivable anaerobic bacteria which could be isolated from subgingival plaque of sheep. Samples were taken from 10 sheep on farms with a known record of broken mouth periodontitis. For assessment of the sampling technique, samples were also taken from freshly exposed tooth roots in killed sheep.

Longitudinal study of untreated periodontitis (II). Microbiological findings.

11 volunteer subjects with advanced chronic periodontitis participated in a 1-year longitudinal clinical and microbiological study. Subgingival plaque was collected at each of 7 visits from 148 pre-selected sites in the left jaw quadrants (test sites) and on the first and last visits, only from 117 sites in the left jaw quadrants (control sites). All sites were examined clinically at each of the 7 visits, and the microbiological markers investigated were the % spirochaetes and % black pigmented Bacteroides species in subgingival plaque.

A new method for assessing the % of spirochaetes in subgingival plaque.

A new method for counting the numbers of spirochaetes in subgingival plaque is described. The technique involves the combined use of a negative stained preparation, dark field microscopy, and an image analysing system. Advantages of the method include: smears need not be made until 2 days after sampling, and can be examined microscopically for up to 1 year after preparation; reproducibility of counts are more than 90% and the data can be computerised.