Susceptibilities of oral bacteria and yeast to mammalian cathelicidins.

The effects of cathelicidins against oral bacteria and clinically important oral yeasts are not known. We tested the susceptibilities of Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Streptococcus sanguis, Candida krusei, Candida tropicalis and Candida albicans to the following cathelicidins: FALL39, SMAP29, and CAP18. SMAP29 and CAP18 were antimicrobial, whereas FALL39 did not exhibit antimicrobial activity. Future studies are needed to determine the potential use of these antimicrobial peptides in prevention and treatment of oral infections.

Molecular analysis of Peptostreptococcus micros isolates from patients with periodontitis.

BACKGROUND: Recent studies provide strong evidence implicating Peptostreptococcus micros in the pathogenesis of various oral infections, including oropharyngeal abscesses and periodontal disease. To date, very little is known regarding the role of P. micros in periodontal disease. Therefore, a genetic analysis was initiated to differentiate among strains of P. micros infecting periodontal patients. METHODS: Sixty DNA samples of P. micros isolated from 15 patients with periodontal disease were evaluated. Arbitrarily primed polymerase chain reactions (AP-PCR) were performed using primer 3 (AGTCAGCCAC) and primer 13 (CAGCACCCAC). The PCR products were analyzed by gel electrophoresis. RESULTS: The primers produced several unique patterns among the strains tested. Primer 3 resulted in 30 different patterns, whereas primer 13 resulted in 31 different patterns, which were distinct from those seen with primer 3. In 8 of 15 patients, the PCR profile was identical for all isolates cultured from that patient, indicating a clonal infection. In 4 of 15 patients, 2 different genotypes were identified. In the remaining 3 patients, all isolates cultured from these patients exhibited a unique genotype. CONCLUSIONS: While P. micros appears to be heterogeneous throughout a population of periodontal patients, each patient is, for the most part, infected with a limited number of genotypes. These results demonstrate the genetic diversity of P. micros and the usefulness of AP-PCR for future epidemiological studies in understanding the role P. micros plays in periodontal disease pathogenesis.