Localization and density of Porphyromonas gingivalis and Tannerella forsythia in gingival and subgingival granulation tissues affected by chronic or aggressive periodontitis.

Porphyromonas gingivalis and Tannerella forsythia have been thought to be associated with periodontitis; however comprehensive histopathological localization of bacteria in affected human periodontal tissues is not well documented. In the present study, we examined formalin-fixed paraffin-embedded gingival and subgingival granulation tissues from 71 patients with chronic periodontitis and 11 patients with aggressive periodontitis, using immunohistochemistry with novel monoclonal antibodies specific to P. gingivalis or T. forsythia, together with quantitative real-time polymerase chain reaction for each bacterial DNA. Immunohistochemisty revealed both bacterial species extracellularly, as aggregates or within bacterial plaque, and intracellularly in stromal inflammatory cells, squamous epithelium, and capillary endothelium of granulation tissue. Combined analysis with the results from polymerase chain reaction suggested that localization and density of T. forsythia is closely associated with those of P. gingivalis, and that bacterial density is a factor responsible for the cell-invasiveness and tissue-invasiveness of these periodontal bacteria. Detection of these bacteria in the capillary endothelium in some samples suggested possible bacterial translocation into the systemic circulation from inflamed gingival and subgingival granulation tissues. Immunohistochemistry with the novel antibodies showed high specificity and sensitivity, and can be used to locate these periodontal bacteria in routinely-used formalin-fixed paraffin-embedded human tissue sections from systemic locations.

Severe lower limb cellulitis: defining the epidemiology and risk factors for primary episodes in a population-based case-control study.

OBJECTIVE: To describe the epidemiology and risk factors for primary episodes of severe lower leg cellulitis (LLC). METHODS: This was a longitudinal cohort study using state-wide data linkage of adults presenting to Western Australian (WA) hospitals with a first ever LLC from January 2002 to December 2013. The study aimed at determining risk factors, medical records from the index patient, together with comparable data from controls matched by age, sex, postcode, and month of admission. RESULTS: During the period, 36 276 patients presented with their first episode of LLC. The incidence increased by 4.7% per annum, reaching 204.8 (95% CI 198.6-211.1) per 100 000 population by December 2013. Analysis of 29 062 case-control pairs showed several conditions with lower limb pathology were independently associated with LLC, including varicose veins (AOR 2.95, 95% CI 2.50-3.48, p < 0.001), lymphoedema (AOR 2.65, 95% CI 1.71-4.10, p < 0.001), tinea pedis (AOR 3.05, 95% CI 1.45-6.42, p 0.003), and saphenous vein harvest during coronary artery bypass grafting (AOR 1.74, 95% CI 1.32-2.30, p < 0.001). Also associated with LLC was obesity (AOR 2.05, 95% CI 1.82-2.31, p < 0.001), renal disease (AOR 1.28, 95% CI 1.14-1.44, p < 0.001), rheumatologic conditions (AOR 2.12, 95% CI 1.72-2.60, p < 0.001), hemiplegia/paraplegia (AOR 1.31, 95% CI 1.13-1.52, p < 0.001), and liver disease (AOR 1.77, 95% CI 1.51-2.06, p < 0.001). CONCLUSIONS: LLC presents a major burden to the health sector and is increasing with an ageing population. Given the high rates of recurrence, long-term morbidity, and economic impact, efforts to reduce primary episodes should be incorporated into the infectious diseases and healthy ageing research agenda.

Possible translocation of periodontal pathogens into the lymph nodes draining the oral cavity.

Numerous publications have reported the presence of periodontopathogenic bacteria in peripheral and central vascular lesions. However, it is unclear how this bacterial translocation occurs. The objective of this study was to investigate whether periodontopathic bacteria are translocated to lymph nodes proximal to the oral cavity. Obtaining lymph node samples is not ethically feasible unless they are excised as part of the surgical management of patients with cancer. This study analyzed formalin-fixed and paraffin-embedded lymph nodes, histologically negative for cancer cell invasion, that were excised from 66 patients with histories of head and neck cancer. Real-time PCR was performed to amplify the 16S ribosomal DNA fragments from Porphyromonas gingivalis, Treponema denticola, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Prevotella intermedia. The relationship between bacterial detection and cancer severity, gender, and the use of anti-cancer therapy was examined by Fisher's exact test. P. gingivalis, T. forsythia, and P. intermedia were present in 17%, 8%, and 8% of the samples of submandibular and submental lymph nodes, respectively. There were no significant relationships between bacterial detection and the cancer disease status, patient gender or use of anticancer therapy. According to these data, it appears that the translocation of periodontopathic bacteria may occur via lymphatic drainage, irrespective of the cancer disease status, gender or anticancer therapy.