Effect of HIV infection on oral microbial colonization and diversity

By the end of 2009, more than 33.3 million people including 2.2 million children worldwide were living with HIV.  A number of studies have demonstrated that individuals with HIV infection are at greater risk for opportunistic oral infection and poor oral health, including progressive gingivitis and periodontitis, candidiasis, oral lesions, and dental caries.  The increased oral diseases may be associated with decreased salivary flow rate and changes in the oral microbiota in saliva of immunocompromised individuals.  Objectives: To characterize quantitatively and qualitatively the bacterial colonization in the saliva of HIV-infected individuals; and to compare the oral microbial diversity profiles of the HIV-infected to the normal healthy controls.  Methods:  Stimulated whole saliva samples were collected from 30 HIV-positive individuals and 40 HIV-negative controls.  The levels of oral bacterial colonization were examined by culture methods.  Meanwhile, total bacterial genomic DNA was isolated from the whole samples.  The microbial diversity was assessed by comparing bacterial 16S rDNA fingerprints generated by PCR and DGGE and analyzed by using BioNumerics and SPSS programs.  Results:   Our results showed that the HIV-positive individuals experienced higher levels of oral bacterial colonization, specifically for total Candida sp., total Lactobacilli sp., and S. mutans.  We also observed that a significant difference in the bacterial 16S rDNA fingerprint profiles and a greater diversity in the HIV-infected individuals compared to the healthy controls.  Conclusion: These preliminary observations suggest that HIV infection may have significant effect on the oral bacterial colonization and the overall composition of bacterial population in saliva.  Thus, final findings of this study could make important contributions to the early diagnosis, prevention and treatment of this disease.  

Supported by research grants U19 DE018385 from the NIDCR/NIH; and New York University Student Research Program.