The relationship between halitosis and gram-negative anaerobic bacteria in oral cavity

To assess the association of halitosis and gram-negative anaerobic bacteria in oral cavity. Method & Materials: The study was analytical and case control in which thirty-four patients with halitosis and 27 normal controls, referred to Department of Oral Medicine in Shahid Beheshti Dental School, have been visited by two dentists and studied microbiologically. Samples for micribiological studies were taken from the base of the tongue by a wooden instrument and immediately transported to liquid thioglycollate medium. The samples were cultured in nutrient culture medium, blood agar, MacConkey agar and chocolate agar after incubation at 37°C for 24 hours in anaerobic jar. Appropriate laboratory tests, such as catalase, coagulase, manitol, gellatinase, oxidase and DNase, were used to make differential diagnosis of cultured bacteria. The results were analyzed, using chi square test, Fisher’s exact test, T test and Mann-Whitney U test. All tests were 2-tailed with alpha set at 0.05. Obligate anaerobic bacteria were cultured in 24 of the cases (%70.1) and 11 of the controls (%40.7). This difference was significant (p=0.036, OR=3.5). Thirty-one cases (%91.2) and 24 controls (%88.9) were cultured-positive for either facultative or obligate anaerobic bacteria (p=ns, OR=1.3). There was no statistically significant difference between the two groups according to cultured-positive individuals for fusobacterium, fusiform bacillus, prevotella, veillonella, haemophilus, spirillum and kingella, but tendency to difference for bacteroides (p=0.083, OR=3.3) and Niesseria (p=0.084, OR=0.4). There is an association between halitosis with obligate anaerobic bacteria.