Differences of Subgingival Microbiota between Young and Elder Rhesus Macaques

Objectives: The rhesus macaque serves as an animal model to study HIV infection and periodontitis. �Previously, we determined that the oral microbiome of the macaque is distinct, albeit similar, to that of the human. �The purpose of this study is to determine similarities between the subgingival plaque of younger vs older animals, who are subject to oral disease.� Methods: Bacterial DNA was isolated from subgingival plaque from 5 young animals (<5 years) and 4 older animals (>12 years), and PCR-amplified using broad range 16S rDNA bacterial primers. �Full-sized amplicons of about 1500 bp were cloned and subsequently sequenced to generate phylogenetic trees for species identification. Results: Based on the analysis of 900 clones, there were 48 predominant species, of which 27 were unique to the macaque.� The remaining species were identified as �human� species.� The most commonly-detected species found in subgingival plaque were Abiotrophia defectiva, Gemella morbillorum �(macaque specific), Streptococcus mitis bv2, and a Lachnospiraceae phylotype.�� �Species of Actinomyces, Veillonella, Eubacterium and related spp., and Prevotella, typically detected in humans, were notably absent in younger monkeys, but present in the older monkeys.� �Conclusions: �The oral microbiome of the subgingival plaque of the rhesus macaque is distinct from that of humans.� Although some macaque species are also found in humans, most are unique to the monkey. �Bacterial profiles of subgingival plaque are age-dependent, with more �typical� periodontal pathogens present in older monkeys.� These findings help to validate using the macaque monkey as a model for human disease. Supported by DE020025.

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