Volatile Sulfur Compounds Produced by the Anaerobic Bacteria Porphyromonas spp. Isolated from the Oral Cavities of Dogs

SIMPLE SUMMARY: Periodontal disease is the most common oral disease in dogs, and their owners usually notice this disorder in their animals via halitosis. The volatile sulfur compounds (VSCs), such as hydrogen sulfide (H(2)S), methyl mercaptan (CH(3)SH), and dimethyl sulfide ((CH(3))(2)S), produced by periodontal-disease-associated bacteria cause halitosis. In addition, VSCs are not only the cause of halitosis, but are also toxic to oral tissues. Porphyromonas gulae is the main pathogenic bacterium in canine periodontal disease. However, the characteristics of the VSCs produced by P. gulae are unknown. The results of the present study demonstrate that P. gulae and other Porphyromonas spp. that were isolated from the oral cavities of dogs with periodontal disease can produce large amounts of H(2)S and CH(3)SH. In particular, the amount of CH(3)SH was dominant. It was suggested that the high levels of H(2)S and CH(3)SH in P. gulae and other Porphyromonas spp. contribute to halitosis and the destruction of periodontal tissues during the progression of periodontal disease in dogs. Appropriate oral care is required to prevent halitosis and the toxic effects of VSCs in dogs with periodontal disease. ABSTRACT: Porphyromonas spp. are oral anaerobic Gram-negative bacteria that form black-pigmented colonies on blood agar and produce volatile sulfur compounds (VSCs), such as hydrogen sulfide (H(2)S), methyl mercaptan (CH(3)SH), and dimethyl sulfide ((CH(3))(2)S), which cause halitosis and the destruction of periodontal tissues. P. gulae is considered the main pathogen involved in periodontal disease in dogs. However, the characteristics of the VSCs produced by P. gulae are unknown. In the present study, VSCs were measured in 26 isolates of P. gulae and some isolates of the other Porphyromonas spp. obtained from the oral cavities of dogs with periodontal disease using an in vitro assay with an Oral Chroma(TM) gas chromatograph. The results demonstrated that P. gulae was able to produce large amounts of H(2)S and CH(3)SH, and the dominant product was CH(3)SH (CH(3)SH/H(2)S was approximately 2.2). Other Porphyromonas spp. that were also obtained from the oral cavities of dogs with periodontal disease indicated similar levels of production of H(2)S and CH(3)SH to those of P. gulae. It is strongly suggested that the high levels of H(2)S and CH(3)SH produced by P. gulae and other Porphyromonas spp. contribute to halitosis and the destruction of periodontal tissues during the progression of periodontal disease in dogs.