microbiological study of the effect of irradiation on the anaerobic oral flora in patients under radiotherapy

ABSTRACT

This work was conducted on 35 patients [27 males and 8 females], their ages were ranging from 20 to 70 years with malignant tumours of the head and neck region. Their salivary glands were free from any pathologic condition, and they were treated by radiation therapy. Salivary stimulated samples were collected aseptically from the patients before, during, immediately after and 6 months after irradiation. Anaerobic bacterial identification and count were done for each specimen. The positive cultures for strict anaerobic microorganisms performed before irradiation included Bacteroides [68%], Veillonella [12%], Peptostreptococci [36%] and Propionobacterium [8%]. There were no significant changes in count of strict anaerobic bacteria during or after irradiation. The disparity of counts necessitated the use of long transformation of data to increase homogenity with remarkable changes in Bacteroides. Also similar changes but of less magnitude were seen in Peptostreptococci and Veillonella, while the level of Fusobacterium slowly increased during treatment and more so 6 months after irradiation. Regarding Propionobacterium, there was a slight rise in the middle of therapy, whereas there was a drop after 6 months and reached the base line