Romanian Biotechnological Letters Vol. 20, No. 4, 2015 Copyright © 2015 University of Bucharest Printed in Romania. All rights reserved ORIGINAL PAPER Romanian Biotechnological Letters, Vol. 20, No. 4, 2015 10662 Virulence Profiles of Bacterial Strains Isolated From Periodontal Lesions Received for publication, February 20, 2015 Accepted, July 10, 2015 CRISTIANA ANTIPA 1 , MARCELA POPA 2* , LUMINIȚA MĂRUȚESCU 2 , CORALIA BLEOTU 3 , LAZAR VERONICA 2 , SERBAN BERTESTEANU 4,5 , RALUCA GRIGORE 4,5 , EUGENIA BEZIRTZOGLOU 6 , SIMONA MARIA RUȚA 3 1 Titu Maiorescu University, Faculty of Dental Medicine, Bucharest, Romania ; 2 Department of Microbiology, Faculty of Biology, University of Bucharest, Research Institute of the University of Bucharest-ICUB, Life, Environment and Earth Sciences, Bucharest, Romania ; 3 Ștefan S Nicolau Institute of Virology Bucharest, Romania ; 4 Head & Neck Surgery Clinic, Colţea Clinical Hospital, Bucharest, Romania; 5 University of Medicine and Pharmacy Carol Davila, Bucharest, Romania; 6 Democritus University of Thrace Faculty of Agricultural Development, Department of Food Science and TechnologyLaboratory of Microbiology, Biotechnology and Hygiene, 68200-Orestiada, Greece * Correspondence address: Department of Microbiology, Faculty of Biology, University of Bucharest Aleea Portocalelor 1-3, 60101 Bucharest ; Tel :+4021 318 1576;Email:bmarcelica@yahoo.com Abstract Periodontitis is a chronic inflammatory disease of polymicrobial etiology that could lead to the destruction of bones and tissues that support the teeth. In spite of the growing data on the pathogenic consortia associated with the disease, currently this information is poorly used to improve diagnostics or developing methods for monitoring the treatment outcome. The investigation of the microbial composition of periodontal pocket or the gingival sulcus in 23 patients with periodontal diseases showed that only 39% of the total analysed samples were harbouring microbial strains etiological linked to periodontal disease or frequently encountered in pathological periodontal conditions, i.e. Actinomyces naeslundii, A. viscosus, Prevotella oralis, Fusobacterium mortiferum, Streptococcus mitis and Bacteroides sp. The microbial strains isolated from the periodontal lesions expressed virulence factors that enable them to colonize and damage the host tissues (i.e. ability to adhere to inert and cellular substratum, pore forming toxins, proteases, DN-ase and siderophore-like molecules). Keywords: periodontal disease, microbial strains, dental biofilm Introduction Periodontitis is a chronic inflammatory disease of polymicrobial etiology that can lead to the destruction of bones and tissues that support the teeth including the alveolar bone, periodontal ligament, cementum, and gingiva (1, 2). The treatment of periodontitis involves elimination or at least control of pathogenic bacteria associated with the disease. However, in spite of the growing data on the pathogenic consortia associated with the disease, currently this information is poorly used to improve diagnostics or developeing methods for monitoring the outcomes of treatment success (3). The increased prevalence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus and Treponema sp. in different forms of periodontal disease has earned them the recognition as diagnostic markers in the disease