cloacae and C. luteola were the most prevalent species amongst isolates of Enterobacteriaceae and Pseudomonaceae from both groups. E. cloacae has been frequently identified amongst clinical oral isolates. 11, 12 and 26 However, C. luteola is rarely isolated from the oral cavity, and infections caused by FAK inhibitor this microorganism include sepsis, meningitis, endocarditis, osteomyelitis and peritonitis. 20 and 38 The HIV group showed the greatest diversity of Enterobacteriaceae and Pseudomonas species, many of which can cause opportunistic infections, such as

Escherichia coli infections, gastro-intestinal infections, 39 endocarditis, 40 urinary infections 41 and Klebsiella pneumonia infections that are often involved with aspiration pneumonia. 42 With respect to CD4 cell count, lower counts of enterobacteria and pseudomonas were observed amongst patients in the subgroup with <200 CD4 cells/mm3. This unexpected result warrants further study. The viral load values were distributed equally amongst the subgroups evaluated. Considering that the studies reporting the prevalence of enterobacteria and Pseudomonas in the oral cavities of HIV-positive patients did not correlate their findings with clinical variables, it was not possible to compare our results to the literature. However, increased oral carriage of Gram-negative

bacilli in the HIV group compared to the control group confirms that carriage rates tend to increase in medically compromised individuals, and the presence of such bacteria in the oral cavity as a putative reservoir of infection should be considered. CTLA-4 inhibitor 43 Regarding treatment, it was not possible to have a fixed therapy protocol for all patients because the treatment strategy would change according to the CD4 lymphocyte level and viral load as well as other relevant clinical variables, such as the occurrence of opportunistic diseases and adverse reactions to medication. HAART is correlated

with lower occurrence of oral diseases. It promotes inhibition of viral replication as well as redistribution and restoration of immunity, resulting in an increase in CD4 cell counts. Within the limits of this study, we could not assess the effect of HAART on the oral microflora. The few studies on this subject report that about protease inhibitors may have anti-Candida activity by inhibiting the protease of this microorganism. 1 and 44 Based on the results obtained, it may be concluded that the HIV-positive group showed a higher prevalence of Enterobacteriaceae and Pseudomonadaceae. No difference in staphylococcus counts was found between the studied groups. Funding: Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP (2004/12382-6). Conflict of interest statement: No conflict of interests. Ethical approval: This study was approved by the Local Ethics Committee (protocol number 012-PH/CEP).