Distribution of biotypes and leukotoxic activity of Aggregatibacter actinomycetemcomitans isolated from Brazilian patients with chronic periodontitis

Brazilian Journal of Microbiology

Elerson Gaetti-jardim Jr.²  Thais Cristiane Wahasugui¹  Paulo Henrique Tomazinho¹  Márcia Martins Marques¹  Viviane Nakano¹  Mario Julio Avila-campos¹ 

[1] ,Universidade Estadual Paulista Faculdade de Odontologia Laboratório de PatologiaAraçatuba SP ,Brasil

关键词: Aggregatibacter actinomycetemcomitans;    biotype;    leukotoxin;    periodontitis;    Aggregatibacter actinomycetemcomitans;    biótipo;    leucotoxina;    periodontite;   

DOI  :  10.1590/S1517-83822008000400011

来源: SciELO

【 摘 要 】

Aggregatibacter actinomycetemcomitans is an important etiologic agent of the periodontitis and is associated with extra-oral infections. In this study, the detection of the ltxA gene as well as the ltx promoter region from leukotoxic A. actinomycetemcomitans isolated from 50 Brazilian patients with periodontitis and 50 healthy subjects was performed. The leukotoxic activity on HL-60 cells was also evaluated. Leukotoxic activity was determined using a trypan blue exclusion method. The 530 bp deletion in the promoter region was evaluated by PCR using a PRO primer pair. A. actinomycetemcomitans was detected by culture and directly from crude subgingival biofilm by PCR using specific primers. By culture, A. actinomycetemcomitans was detected in nine (18%) of the periodontal patients and one (2%) healthy subject. However, by PCR, this organism was detected in 44% of the periodontal patients and in 16% of the healthy subjects. It was verified a great discrepancy between PCR detection of the ltx operon promoter directly from crude subgingival biofilm and from bacterial DNA. Only one periodontal sample harbored highly leukotoxic A. actinomycetemcomitans. Moreover, biotype II was the most prevalent and no correlation between biotypes and leukotoxic activity was observed. The diversity of leukotoxin expression by A. actinomycetemcomitans suggests a role of this toxin in the pathogenesis of periodontal disease and other infectious diseases.

【 授权许可】

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