RESUMO
Background: Behcet's disease is a chronic, relapsing, multi-system inflammatory disorder, clinically characterized by recurrent oral and genital ulcers, skin lesions, and uveitis. Environmental factors such as infectious agents have also been implicated in its pathogenesis. Aims and Objectives: to isolate different types of bacteria from patients with oral ulceration of Behcet's disease that may contribute in pathogenesis of these oral ulcers and tissue typing was done for those patients. Design: Cross-sectional study. Setting: Al-Karamma Teaching Hospital from January 2000 – Septomber 2000 at Baghdad city. Patients and methods: Study included 40 patients with Behcet's disease (BD). The other set was control group, consisted of 30 healthy volunteer's age- and sex-matched with first group from staff employees. Two swabs were taken from basal area of oral ulcer for direct exam and culture. Human Leukocytes Antigens typing was done for them by serological method.Results : Direct examination of their oral ulcer swabs showed significant difference regarding pus cells 87.5% (p= 0.0001) and red blood cells 75% (p= 0.0001). Gram stain showed significant increased in G+ cocci 95% (p= 0.0001). Other swab was cultured on Blood, Chocolate and MacConkey agar. The isolated bacteria were Streptococcus Pyogenes group A 75% (p= 0.0001)and Staphylococcus aureus 47% (p= 0.0001). HLA typing were done for them and 95% of them were HLA-B5 positive Conclusions: Microbial infection by Streptococci has been implicated in the development of Behçet's disease by trigger cross-reactive autoimmune responses in those patients. The frequency of the HLA-B51 allele is high among patients with Behçet's disease.