xylosus, S. saprophyticus and S. hominis have been reported in previous studies.

26, 27, 29, 30, 31 and 32 In our results, S. sciuri, S. simulans and S. chromogenes were identified. These species were not found in previous studies of oral samples. Some of these species, although isolated infrequently, may cause infections in humans, such as urinary tract infections, mTOR inhibitor bacteremia, endocarditis, osteomyelitis, cellulitis and cerebral empyema. 33 and 34 Counts of staphylococci were lower in the oral cavities of patients with low viral load (<400 copies/ml), but no difference was observed in relation to CD4 cells. No previous studies were found with which to compare these data. Enterobacteria and pseudomonas were identified in the oral cavities of 77.7% of the HIV-positive group. The control group showed a lower isolation frequency (44.4%) in the oral cavity. The increased oral prevalence of these microorganisms seems to be associated with systemic and local factors. However, data in the literature are still controversial. Jobbins et al.3 reported isolation of coliforms from 49% of patients with malignancy. A low prevalence of these microorganisms in the elderly and mentally disabled patients was reported.17 and 18 Senpuku et al.14 isolated Enterobacteriaceae

from 16% of elderly patients and from 6% of controls. A higher prevalence of enterobacteria in the oral cavity was observed by Santos and Jorge 11 in healthy Brazilian individuals (51%). Hägg et al. 35 reported a significant increase in the prevalence of enterobacteria buy BKM120 after insertion of fixed orthodontic appliances. Zhu et al., 36 studying

stroke Edoxaban patients at three different stages (acute phase, upon discharge from the hospital and 6 months later), observed that the oral carriage rate of coliforms was significantly lower at 6 months after hospital discharge, but found no significant relationship between the presence of coliforms and other variables studied (age, gender, plaque index, bleeding index, DMFT, denture wearing, dysphagia, smoking, diabetes and tooth brushing difficulty). Other studies with HIV-positive patients in different countries found a low prevalence of enterobacteria and/or pseudomonas in the oral cavity. Schmidt-Westhausen et al.37 obtained an enterobacteria prevalence of 22%. Tsang and Samaranayake15 reported the isolation of Enterobacteriaceae (26.3%) and P. aeruginosa (15.1%). The only Brazilian study regarding these microorganisms in the oral cavities of HIV-positive patients was conducted by Figueirêdo et al., 16 who found Enterobaceriaceae in 96.4% of isolates and P. aeruginosa, the only Pseudomonas identified, in 3.6% of isolates. According to Santos and Jorge, 11 some authors have noted discrepancies in the prevalence of these microorganisms in the oral cavities of individuals from developed and developing countries, hypothesizing that the incidence of these microorganisms in the oral cavity may be related to high numbers of coliforms in drinking water and foods.