Attachment loss in Moroccan early onset periodontitis patients and infection with the JP2-type of Actinobacillus actinomycetemcomitans

Background: A clone of Actinobacillus actinomycetemcomitans (JP2) with increased leukotoxin production and characterized by a 530-bp deletion in the leukotoxin gene operon is endemically present in Morocco and strongly associated with the presence of early onset periodontitis (EOP). Objectives: To compare patterns of attachment loss among EOP-patients with or without JP2-type of A. actinomycetemcomitans in dental plaque. Material and methods: Among 45 Moroccan adolescents with EOP (i.e. one or more teeth with attachment loss greater than or equal to 3 mm) 39 had cultivable plaque samples. Fifteen (38.5%) were culture-positive for A. actinomycetemcomitans of the JP2-type as determined by PCR, and 24 (61.5%) were not (mean age 16.5 years in both groups). Results: EOP-patients culture-positive for A. actinomycetemcomitans of the JP2-type had significantly more teeth with attachment loss (mean 5.1, median 4.0) than EOP-patients not culture-positive for A. actinomycetemcomitans of the JP2-type (mean 2.8 teeth, median 1.0) (p = 0.02), and higher attachment loss (mean 4.3 mm vs. 3.4 mm; median 4.0 mm vs. 3.0 mm) (p = 0.01). No major differences could be detected between the two groups in the pattern of affected teeth in the dentition. Conclusions: The study demonstrates increased periodontal destruction among EOP-patients culture-positive for A. actinomycetemcomitans of the JP2-type compared with EOP-patients without the JP2-clone.