Comparative detection of six putative periodontal pathogens in Sudanese and Norwegian adult periodontitis patients
The aim of this study was to describe the periodontal microflora in the Sudanese and Norwegian population by standard cultivation techniques and by cultivation and DNA analysis. Twenty-five Sudanese and 18 Norwegians with moderate to severe periodontitis were selected for this study. Subjects had at least 4 pockets > 6 mm, no periodontal treatment, and no antibiotics during the last six months. The parameters considered in the examination were plaque index (PI), bleeding on probing (BOP), probing depth (PD), and attachment level (AL).Three to 10 sites per patient were selected. Samples were collected using paper points. Samples were cultured and colonies were characterized by morphology, Gram staining and catalase production. Cultures of P. gingivalis (P.g.), P. intermedius (Pi.), F. nucleatum (F.n.), Capnocytophaga (C.), and A. actinomycetemcomitans (A.a.) were quantified. P.g. was detected 2.4 and 2.7 times more frequently in Norwegians (86.6%) than in Sudanese (70.3%). Similar results were obtained for P i. Ala. was found in 17.2% Sudanese sites versus 16.8% of Norwegian sites. F.n. was detected in 68.0% of the Sudanese subjects and 100% of Norwegians. Capnocytophaga species were detected in significantly higher frequencies in Sudanese than in Norwegians. Enteric rods were found in the Sudanese but were not detected in the Norwegians. More patients and sites showed Pg., P.i., and F.n. when the probe was used. P.g. was detected by cultivation in 36% of the patients versus 96% by the DNA probe. P.i. was detected in 40% of the patients by culture and 76% by DNA. F.n. was found in 68% of the patients by culture versus 100% by DNA probe. Ala. was detected more by cultivation (28%) than by DNA probe (16%).The results showed that most Sudanese and Norwegians tested positive for Pg., Pi., F.n., and Capnocytophaga, while 33% tested positive for Ala. P.g., P.i., and F.n. were found in lower percentages in Sudanese patients when compared to Norwegians.
In conclusion, lower numbers of sites were positive for P.g., Pi., and F.n. when the culture method was used. There was a significantly higher number of positive sites for Capnocytophaga in Sudanese to Norwegians, while Ala. had a similar occurrence in both populations. DNA probes demonstrated that Pg., P i., and F.n. were detected in significantly higher numbers of patients and sites. [c.c.]
Ali R.W.,V. Bakken, R. Nilsen, and N. Skaug, J Periodont, 65:1046,1994