Distribution of 8 periodontal microorganisms in family members of Chinese patients with aggressive periodontitis

•The red complex bacteria were frequently detected in probands and relatives.•The detection of some bacteria in probands was consistent with their relatives.•Most probands shared the same fimA genotype of P. gingivalis with their relatives.

ObjectiveTo date, no information on the distribution of periodontal microorganisms among family members of Chinese patients with aggressive peridontitis (AgP) is available. The aim of the present study was to investigate the probability of transmission of eight periodontal microorganisms between patients with aggressive periodontitis and their family members.DesignSaliva and pooled subgingival plaque samples were collected from 103 participants from 41 nuclear families (including 41 AgP probands, 19 mothers, 22 fathers, 21 siblings). Eight periodontal microorganisms, including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Campylobacter rectus, Prevotella intermedia, Prevotella nigrescens and Fusobacterium nucleatum were detected in these samples by the polymerase chain reaction (PCR). In addition, the distribution of fimA genotypes was assessed in P. gingivalis-positive individuals by PCR.ResultsP. gingivalis, T. forsythia, T. denticola, C. rectus and F. nucleatum were the most frequently detected species both in AgP probands and in their relatives. Kappa statistical analysis revealed that the detection of A. actinomycetemcomitans (Kappa = 0.503) and F. nucleatum (Kappa = 0.565) in probands was highly consistent with that in their relatives. Most probands shared the identical fimA genotype of P. gingivalis with their relatives.ConclusionsOur results suggested that the intrafamilial transmission of periodontal microorganisms may occur between Chinese patients with aggressive periodontitis and their relatives.