CD59 and chronic periodontitis: The frequency of expression of most virulence genes (adhesins, toxins, iron acquisition, protectins and PAIs) was not associated with any of the three diagnoses (gingivitis, moderate periodontitis and chronic periodontitis), however afa was significantly associated with gingivitis and hlyA with gingivitis and chronic periodontitis (Chi-square test p <0.05, Table 1).