Background: JP2 clone of Aggregatibacter actimycetemcomitans has been mainly recovered from adolescents living in northwestern Africa or African descends. A very strong association between this and Aggressive periodontitis (AgP) specifically its localized form was found among adolescents.

Objectives: The purpose of the current study to evaluate the prevalence of Aggregatibacter actimycetemcomitans (Aa) genotype strains and to determine the effect of presence of these strains on the severity of localized aggressive periodontitis (LAP) patients at base line presentation among the Egyptian population.

Materials and Methods: This study was done on sixty patients (54 females and 6 males) aged (9-26) years diagnosed clinically and radiographically as a LAP patient were selected from examination of 270 periodontitis patients. The presence of Aa (JP2 and non-JP2) strains in the collected microbiological samples were identified by conventional PCR. All clinical parameters including plaque index (PI), gingival index (GI), probing depth (PD) and clinical attachment level (CAL) were taken for all the patients at base line.

Results: This study found that: Aggregatibacter actinomycetemcomitans (JP2 and non-JP2) was identified by PCR in 20/60 patients of the total participants in this study. Presence of Aa specifically its JP2 strain was associated with a significant increase in the estimated clinical parameters, which appeared clinically in the form of more destructive LAP cases at base line presentation.

Conclusion: The identification of Aa in minority of cases excludes the role of Aa as a major bacterial risk factor in LAP. JP2 and non-JP2 strain infection …