The facultative human oral pathogen Prevotella histicola in equine cheek tooth apical/ periapical infection: a case report.

BACKGROUND: Prevotella histicola is a facultative oral pathogen that under certain conditions causes pathologies such as caries and periodontitis in humans. Prevotella spp. also colonize the oral cavity of horses and can cause disease, but P. histicola has not yet been identified. CASE PRESENTATION: A 12-year-old Tinker mare was referred to the clinic for persistent, malodorous purulent nasal discharge and quidding. Conservative antibiotic (penicillin), antiphlogistic (meloxicam), and mucolytic (dembrexine-hydrochloride) treatment prior to referral was unsuccessful and symptoms worsened. Oral examination, radiography, sino-/ rhinoscopy, and standing computed tomography revealed severe apical/ periapical infection of the upper cheek tooth 209 with accompanying unilateral sinonasal inflammation and conchal necrosis. The tooth exhibited extensive subocclusal mesial infundibular cemental hypoplasia and caries, and an occlusal fissure fracture. After mechanical debridement and thermoplastic resin filling of the spacious subocclusal carious infundibular lesion, the tooth was extracted intraorally. The sinusitis and conchal necrosis were treated transendoscopically. Selective bacteriological swab cultures of affected tooth roots and subsequent matrix-assisted laser desorption ionization-time of flight mass spectrometry showed an infection with the obligate anaerobic, Gram-negative bacterium P. histicola. Surgical intervention and adapted antibiotic therapy led to normal healing without complications. CONCLUSIONS: This study provides the first documented case of dental infection in a horse caused by P. histicola at once indicating necessity of more sufficient microbiological diagnostics and targeted antibiotic treatment in equine dental practice. This finding is also conducive to understand species-specific Prevotella diversity and cross-species distribution.

Periodontitis induces endothelial dysfunction in mice.

The treatment of periodontitis has numerous positive effects on established chronic health conditions, including cardiovascular disease and diabetes. However, ethical considerations do limit the establishment of human trials to investigate whether periodontitis promotes the early stages of chronic conditions. Therefore, the aim of this study was to investigate whether periodontitis induces endothelial dysfunction in hyperlipidemic apolipoprotein E gene-deficient (ApoE-/-) mice. Forty-five 8-week-old ApoE-/- mice were challenged by oral lavage with Porphyromonas gingivalis and Streptococcus gordonii for 4 weeks. A subgroup of animals (n = 15-17/group) was placed in a metabolic chamber immediately before euthanasia at 4 weeks to measure VO2/CO2 concentrations and voluntary locomotion. In infected and control animals alveolar bone levels were measured by x-ray imaging and endothelial function was determined by measuring endothelial-dependent vasorelaxation of aortic rings. The mRNA expression levels of serum amyloid A and tumor necrosis factor were determined in liver tissues by qRT PCR and protein concentrations in serum by ELISA. Caecal contents were analysed by sequencing to determine changes to the gut microbiota to investigate linkages between microbiome and systemic changes. The results showed that oral lavage of P. gingivalis and S. gordonii for 4 weeks, initiated periodontitis in ApoE-/- mice, similar to the human situation. The oral inflammation was accompanied by a significant increase in mRNA expression of pro-inflammatory mediators serum amyloid A1 and tumor necrosis factor in the liver. Mice with periodontitis also exhibited impaired endothelial-dependent vasorelaxation responses to acetylcholine. This systemic response was connected to increased energy expenditure, locomotion and respiratory quotient. No differences were detected in caecal microbiota between the infected and control animals. Overall, this is the first report that provide evidence that periodontitis induces endothelial dysfunction in mice. Other systemic responses observed in response to the local reaction need further investigation. The study suggests that early prevention of periodontitis may help limit the early stages of endothelial dysfunction that is linked to atherogenesis in humans.

In-vivo imaging revealed antigen-directed gingival B10 infiltration in experimental periodontitis.

Our previous study demonstrated that IL-10 secreting B (B10) cells alleviate inflammation and bone loss in experimental periodontitis. The purpose of this study is to determine whether antigen-specificity is required for the local infiltration of B10 cells. Experimental periodontitis was induced in the recipient mice by placement of silk ligature with or without the presence of live Porphyromonas gingivalis (P. gingivalis). Donor mice were pre-immunized by intraperitoneal (IP) injection of formalin-fixed P. gingivalis, or PBS as non-immunized control. Spleen B cells were purified and treated with LPS and CpG for 48 h to expand the B10 population in vitro. Fluorescence-labelled B10 cells were transferred into the recipient mice by tail vein injection and were tracked on day 0, 3, 5 and 10 using IVIS Spectrum in vivo imaging system. The number of B10 cells and P. gingivalis-binding B cells were significantly increased after in vitro treatment of LPS and CpG. On day 5, the fluorescence intensity in gingival tissues was the highest in mice transferred with B10 cells from pre-immunized donor mice. Gingival expression of IL-6, TNF-α, RANKL/OPG ratio and periodontal bone loss in recipient mice were significantly reduced, and the expression of IL-10 and the number of CD19+ B cells were significantly increased after pre-immunized B10 cell transfer in the presence of antigen, compared to those with non-immunized B10 cell transfer or no antigen presence. This study suggests that antigen specificity dictate the local infiltration of B10 cells into periodontal tissue and these antigen-specific B10 cells promote anti-inflammatory responses.

Hyperbaric oxygen therapy in a case of cervical abscess extending to anterior mediastinum, with isolation of Prevotella corporis.

We present a case of an odontogenic abscess, first spreading at the lateral cervical level and then in mediastinum. We isolated an anaerobic bacterium, Prevotella corporis, rarely documented in literature. The mortality rates of cervical abscesses secondary to odontogenic infections and complicated by mediastinitis vary from 10% to 40%. Treatment of descending mediastinitis involves multidisciplinary teams such as otorhinolaryngology, thoracic surgeons, infectious disease physicians, anesthetists and intensivists. Due to the combined treatment with surgical drainage within 48 hours of hospitalisation, antibiotics and subsequent hyperbaric oxygen therapy, we have achieved complete recovery of the patient.

The involvement of C5a in the progression of experimental arthritis with Porphyromonas gingivalis infection in SKG mice.

BACKGROUND: Epidemiological evidence to suggest that periodontal disease (PD) is involved in the progression of rheumatoid arthritis (RA) is increasing. The complement system plays a critical role in immune responses. C5a has been implicated in chronic inflammatory diseases, including PD and RA. Porphyromonas gingivalis is the major causative bacteria of PD and can produce C5a. Therefore, it is hypothesized that P. gingivalis infection is involved in the progression of RA by elevating C5a levels. In the present study, P. gingivalis-infected RA model mice were established to investigate the involvement of C5a. METHODS: SKG mice orally infected with P. gingivalis were immunized with intraperitoneal injection of laminarin (LA) to induce arthritis. Arthritis development was assessed by arthritis score (AS), bone destruction on the talus, histology, and serum markers of RA. In order to investigate the effects of serum C5a on bone destruction, osteoclast differentiation of bone marrow mononuclear cells was examined by using serum samples from each group of mice. The relationship between C5a levels and antibody titers to periodontal pathogens in patients with RA was investigated by enzyme-linked immunosorbent assay. RESULTS: P. gingivalis oral infection increased AS, infiltration of inflammatory cells, bone destruction on the talus, and serum markers of RA in mice immunized with LA. The addition of serum from LA-injected mice with the P. gingivalis oral infection promoted osteoclast differentiation, and the addition of a neutralization antibody against C5a suppressed osteoclast differentiation. C5a levels of serum in RA patients with positive P. gingivalis antibody were elevated compared with those in RA patients with negative P. gingivalis antibody. CONCLUSIONS: These results suggest that P. gingivalis infection enhances the progression of RA via C5a.

[The Vulnerable Heel of Achilles: Intratendinous Abscess Following a Cat Bite]. / Die vulnerable Ferse des Achilles ­ intratendinöser Abszess nach Katzenbiss.

An 83-year-old patient suffered a cat bite dorsally to the Achilles tendon. In the further course, he developed an isolated intratendinous abscess of the Achilles tendon, which was surgically revised twice and subsequently healed with antibiotic treatment. In Germany, about 40,000 bite injuries of different origins occur annually. Most of these injuries are cat or dog bites, while human bites are rare. Although the course is often complicated, there are no standard recommendations for treatment. An intratendinous abscess after animal bite injury has not been described in the literature as yet.

Descending necrotizing mediastinitis: a conservative approach.

Descending necrotizing mediastinitis (DNM) is a now-rare complication of dental and pharyngeal infections. Reports in the literature have emphasized the need for early, aggressive surgical intervention. We present a case of DNM with bilateral empyemas that arose secondary to a perforated pharyngeal abscess. The patient was successfully managed conservatively with intravenous antibiotics and intercostal drainage. We conclude that conservative management with antibiotics and image-guided percutaneous pleural drainage may be initially appropriate for the stable patient.

Radiography-based score indicative for the pathogenicity of bacteria in odontogenic infections.

OBJECTIVE: To develop a new radiography-based score to assess the potential of bacteria to cause odontogenic infections derived from the occurrence of bacteria at small or large radiographical lesions. MATERIALS AND METHODS: The patients analyzed were a sub-population from a large randomized clinical trial comparing moxifloxacin and clindamycin in the treatment of inflammatory infiltrates and odontogenic abscesses. Routine radiographs were used to analyze the area of the periapical radiolucent lesions. Lesions were stratified by their radiographically measured area as large (>9 mm(2)) or small (≤9 mm(2)). A risk ratio was calculated for each species from the frequency of their occurrence in large vs in small lesions. RESULTS: Fifty-one patients, 19 with abscesses and 32 with infiltrates, were evaluated. Overall, the radiographical lesion areas ranged from 0.4-46.2 mm(2) (median = 9 mm(2)). An increased risk (risk ratio >1) to occur at large abscess lesions was observed for Prevotella (P.) oralis, P. buccae, P. oris, P. intermedia, Fusobacterium nucleatum and Streptococcus (Strep.) anginosus group. An increased risk to occur at large infiltrate lesions was found for Strep. salivarius, Strep. parasanguis, Strep. anginosus group, Capnocytophaga spp., Neisseria (N.) sicca, Neisseria spp., Staphylococcus (Staph.) aureus, P. intermedia, P. buccae, Prevotella spp. and P. melaninogenica. CONCLUSIONS: The radiography-based score suggests that certain Prevotella spp., F. nucleatum and Strep. anginosus groups play a crucial role in the pathogenesis of odontogenic abscesses, and that various streptococci, Neisseria spp., Capnocytophaga spp., Staph. aureus and Prevotella spp. are involved in the pathogenesis of odontogenic infiltrates.

IL-17 is involved in bone resorption in mouse periapical lesions.

Periapical lesions are induced by bacterial infection of the dental pulp and result in destruction of the surrounding alveolar bone. Although various immunological studies concerning periapical bone resorption have been reported, the role of cytokines in the formation of periapical lesions remains unclear. In this study, the role of IL-17A in periapical lesions in mice was investigated. Normal C57BL/6, IFN-gamma(-/-), TNF-alpha(-/-), and IL-17A(-/-) mice were subjected to pulp exposure and infected with Prevotella intermedia (ATCC25611) and Porphyromonas gingivalis (ATCC33277) in the mandibular first molar. Periapical lesions were determined by muCT on day 21 after infection, and 3D visual construction was performed using 3D picture quantification software. The expression of IL-17A mRNA in periapical lesions was determined by the RT-PCR and real-time RT-PCR method. Periapical lesions developed in wild-type, IFN-gamma(-/-), and TNF-alpha(-/-) mice after infection with P. intermedia and P. gingivalis. However, periapical lesions were not observed in IL-17A(-/-) mice. The expression of IL-17A mRNA was significantly induced in periapical lesions of wild-type mice after infection. These results suggest that IL-17A, but not IFN-gamma or TNF-alpha, plays an important role in the formation of periapical lesions.

Chest wall abscess due to Prevotella bivia.

Prevotella bivia is associated with pelvic inflammatory disease. A 77-year-old man developed a rapidly growing chest wall abscess due to P. bivia within days. He underwent surgical resection of the infected area; his postoperative course was uneventful. This is the first case of chest wall abscess due to P. bivia infection. Its correct diagnosis cannot be underestimated because fulminant infections can occur in aged or immunocompromised patients if treated incorrectly. Prompt, appropriate surgical management, and antibiotic therapy affect treatment outcome.

Topical H2 antagonist prevents periodontitis in a rabbit model.

Cimetidine is a powerful H2 receptor antagonist that eliminates histamine's effects on chemotaxis, phagocytosis, and superoxide anion production by phagocytes. The purpose of this study was to analyze the clinical and histopathological changes associated with experimental periodontitis in rabbits in response to topically applied cimetidine. Experimental periodontitis was induced in 21 New Zealand White rabbits using Porphyromonas gingivalis (10(9) CFU) topically applied three times a week for a 6-week period to previously ligatured teeth. Topical application of cimetidine in a liposome carrier for the prevention of periodontitis was evaluated in four groups of four animals each: 1, 10, and 100 mg/ml and no treatment (positive control). In addition, there was a vehicle group (n = 3) that received liposome preparation (carrier) only, and two animals with ligature application alone served as negative controls. Periodontal disease was quantified by direct visualization and radiographical evaluation of bone loss on defleshed skulls and by histological analyses of sections stained with hematoxylin-eosin and tartrate-resistant acid phosphatase. In the no-treatment (positive control) and liposome (vehicle) groups, direct visualization and radiological measurements revealed statistically significant bone loss compared to the negative control. Application of cimetidine at all concentrations tested inhibited inflammation and bone loss by >90%. Histological findings revealed that ligated sites of the positive control and vehicle groups showed significant reduction in bone level (P < 0.05) compared to the three cimetidine groups, with a marked decrease in inflammation. The findings of this study provide morphological and histological evidence that topically active cimetidine is a potent inhibitor of P. gingivalis-elicited periodontal inflammation, arresting and/or preventing tissue destruction and influencing cell populations present in the inflammatory cell infiltrate.

Lemierre's syndrome: Porphyromonas asaccharolytica as a putative pathogen.

A case of Lemierre's syndrome is reported in which metastatic abscesses resulted from septic thrombophlebitis of the internal jugular vein secondary to bacterial pharyngitis. A 32-year-old male suffering from a painful left-sided neck mass, sore throat, and fever was admitted to our hospital. Computed tomography revealed thrombosis of the left internal jugular vein, septic pulmonary emboli, and a liver abscess. Blood culture showed Porphyromonas asaccharolytica. Although empyema occurred transiently during the treatment, the patient recovered following prolonged antimicrobial therapy. Although Fusobacterium species are a well-known cause of Lemierre's syndrome, cases in whom Porphyromonas species was isolated have scarcely been reported. Moreover, case reports from Japan have been few.

The rim sign in hepatic abscess: case report and review of the literature.

UNLABELLED: We studied a previously healthy patient who presented with a 3-wk history of fever, flu-like symptoms and abdominal pain. METHODS: Blood cultures were positive for Escherichia coli. A computed tomography (CT) scan revealed a 2-cm low-density focus in the right hepatic lobe. A technetium-99m-mebrofenin scan showed a photopenic area in the right hepatic lobe surrounded by a rim of activity greater than the adjacent parenchymal activity. RESULTS: Gallbladder visualization was normal and the diagnosis of hepatic abscess was made. CT-guided percutaneous drainage of the lesion yielded six cc of pus, the culture of which grew E. coli, Prevotella and Bacteroides fragilis. Drainage and a 6-wk course of intravenous antibiotics were followed by clinical improvement and resolution of the abscess by CT. CONCLUSION: The rim sign and its possible mechanism of causation in hepatic abscess are discussed in this report, together with a review of the literature.