This observation is further confirmed in our study where the highest scores were obtained by testing the A. funkei strains with a full extraction protocol. Sequencing of the 16S rRNA gene proved to be a reliable tool for identification of this bacterium, but because of its complexity and higher costs, it may not be available in all laboratories. Bearing in mind the great genetic heterogeneity of the genus Actinomyces [14], the 12 polymorphisms between the investigated strains and the A. funkei type strain (Table 2) brought up the question of discovery of a new Actinomyces species. However, DNA–DNA hybridization confirmed that our investigated strains represent a 16S rRNA gene variant of A. funkei.