title: In Situ Anabolic Activity of Periodontal Pathogens Porphyromonas gingivalis and Filifactor alocis in Chronic Periodontitis.
abstract: Porphyromonas gingivalis and Filifactor alocis are fastidious anaerobic bacteria strongly associated with chronic forms of periodontitis. Our understanding of the growth activities of these microorganisms in situ is very limited. Previous studies have shown that copy numbers of ribosomal-RNA precursor (pre-rRNA) of specific pathogen species relative to genomic-DNA (gDNA) of the same species (P:G ratios) are greater in actively growing bacterial cells than in resting cells. The method, so-called steady-state pre-rRNA-analysis, represents a novel culture-independent approach to study bacteria. This study employed this technique to examine the in situ growth activities of oral bacteria in periodontitis before and after non-surgical periodontal therapy. Sub-gingival paper-point samples were taken at initial and re-evaluation appointments. Pre-rRNA and gDNA levels of P. gingivalis and F. alocis were quantified and compared using reverse-transcriptase qPCR. The results indicate significantly reduced growth activity of P. gingivalis, but not F. alocis, after therapy. The P:G ratios of P. gingivalis and F. alocis were compared and a low-strength, but statistically significant inter-species correlation was detected. Our study demonstrates that steady-state pre-rRNA-analysis can be a valuable culture-independent approach to studying opportunistic bacteria in periodontitis.
authors.affiliation: Divison of Periodontics, Department of Stomatology, Medical University of South Carolina, Charleston, SC 29425, USA.|Lieutenant, Dental Corps, Navy Professional Medicine Development Center, Bethesda, MD 20889, USA.
authors.forename: Ralee
authors.initials: R
authors.lastname: Spooner
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA.
authors.forename: Kris M
authors.initials: KM
authors.lastname: Weigel
authors.affiliation: Department of Periodontology, University of Florida, Gainesville, FL 32610, USA.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Harrison
authors.affiliation: Department of Periodontology, University of Florida, Gainesville, FL 32610, USA.
authors.forename: KyuLim
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA.
authors.forename: Gerard A
authors.initials: GA
authors.lastname: Cangelosi
authors.affiliation: Department of Oral Health Sciences, Medical University of South Carolina, Charleston, SC 29425, USA.|Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC 29425, USA.
authors.forename: Özlem
authors.initials: Ö
authors.lastname: Yilmaz
mesh_terms: D000328:Adult; D001421:Bacteria, Anaerobic / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D058491:Bacterial Load; D055113:Chronic Periodontitis / Q000382:microbiology* / Q000628:therapy; D000068016:Eubacteriales / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D005260:Female; D016680:Genome, Bacterial; D006801:Humans; D008297:Male; D008875:Middle Aged; D016966:Porphyromonas gingivalis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D055815:Young Adult