Non-oral, aerobic, Gram-negative bacilli in the oral cavity of Thai HIV-positive patients on Highly-active anti-retrovirus therapy medication.

In the present study, we identified and evaluated the antibiotic susceptibility of 96 independent, aerobic, Gram-negative bacillus isolates from 255 Thai HIV-positive adults who were on Highly-active anti-retrovirus therapy (HAART) medication. Another 46 isolates from HIV non-HAART individuals, vertically transmitted HIV-positive individuals, and non-HIV controls were included for comparison. A total of 103 strains were tested for antibiotic susceptibility using disc diffusion for screening and E-test for minimal inhibitory concentration determination, with special attention on extended-spectrum beta-lactamase (ESBL) isolates. Pseudomonas aeruginosa, Pseudomonas luteola, Burkholderia cepacia, Aeromonas hydrophila, Klebsiella, and Enterobacter species were the most common bacteria. All strains were resistant against penicillin, amoxicillin, clindamycin, and metronidazole. No ESBL isolates were found.

Periodontal disease in a remote Asian population: association between clinical and microbiological parameters.

OBJECTIVE: The aim was to clinically and microbiologically describe the periodontal conditions in a remote adult Asian population with poor oral hygiene. METHODS: The subjects were 30-60-year-old adults of Karen Hill tribes with no access to dental care. Eighty-six subjects were selected randomly. Clinical registrations included number of remaining teeth, plaque index (PlI), bleeding on probing (BoP), clinical attachment loss (CAL), and probing pocket depth (PPD). Subgingival plaque samples were collected and analyzed with the checkerboard method. RESULTS: Subjects of the study group had mean number of remaining teeth of 26.5 despite the abundant plaque and a high bleeding score. Severe periodontitis (CAL ≥ 7 mm) was recorded in 12.9% of the youngest age group (30-39 years) while it was significantly higher (52%) in the middle group (40-49 years) and (60%) in the eldest age group (50-60 years). Pathological pocketing (PPD ≥ 7 mm) was significantly lower in all age groups. Age, betel chewing, and a microbiological cluster including at least one of Prevotella tannerae, Filifactor alocis and Porphyromonas endodontalis significantly correlated with the severity of periodontal disease. CONCLUSION: Age, betel chewing, and a new bacterial complex other than the "red complex" correlated to periodontal breakdown in this remote adult Asian population.

[Severe ketoacidosis in breastfeeding woman with low energy and carbohydrate intake]. / Svår ketoacidos hos ammande kvinna med lågt energi- och kolhydratintag.

Ketoacidosis is a life threatening condition usually caused by diabetes mellitus or alcohol. In this case report we present a lactating woman who developed a severe ketoacidosis a few weeks post partum. Her nutritional status was inadequate due to illness and a diet low on carbohydrates. Five case reports regarding ketoacidosis in lactating women have previously been described in the literature. This case report highlights the importance of nutrition during periods of breast feeding.

Microbiome of peri-implant infections: lessons from conventional, molecular and metagenomic analyses.

Osseointegrated dental implants are now a well-established treatment option in the armament of restorative dentistry. These technologically advanced devices are designed to functionally and esthetically replace missing teeth. Despite the revolutionary advances that implants have incurred, they have also provided the oral cavity with new artificial surfaces prone to the formation of oral biofilms, similarly to the hard tissue surfaces of natural teeth. Biofilm formation on the implant surface can trigger the inflammatory destruction of the peri-implant tissue, in what is known as peri-implantitis. The mixed microbial flora of peri-implant infections resembles that of periodontal infections, with some notable differences. These are likely to expand with the ever increasing application of metagenomics and metatrascriptomics in the analysis of oral ecology. This review presents the wealth of knowledge we have gained from microbiological methods used in the characterization of peri-implant microflora and sheds light over potential new benefits, as well as limitations, of the new sequencing technology in our understanding of peri-implant disease pathogenesis.

Peri-implant infections of oral biofilm etiology.

Biofilms are complex microbial communities that grow on various surfaces in nature. The oral micobiota tend to form polymicrobial biofilms, particularly on the hard mineralized surfaces of teeth, which may impact on oral health and disease. They can cause inflammation of the adjacent tooth-supporting (periodontal) tissues, leading to destructive periodontal disease and tooth loss. The emergence of osseointegrated dental implants as a restorative treatment option for replacing missing teeth has also brought along new artificial surfaces within the oral cavity, on which oral bacteria can form biofilms. As in the case of natural teeth, biofilms on implant surfaces may also trigger infection and cause inflammatory destruction of the peri-implant tissue (i.e. peri-implantitis). While there are strong similarities in the composition of the mixed microbial flora between periodontal and peri-implant infections, there are also a few distinctive differences. The immunological events underlying the pathogenesis of peri-implant infections are qualitatively similar, yet more extensive, compared to periodontal infections, resulting in a faster progression of tissue destruction. This chapter summarizes the current knowledge on the microbiology and immunology of peri-implant infections, including findings from the peri-implant crevicular fluid, the inflammatory exudate of the peri-implant tissue. Moreover, it discusses the diagnosis and current approaches for the treatment of oral infections.

The effect of the local use of chlorhexidine in surgical treatment of experimental peri-implantitis in dogs.

AIM: To evaluate the effect of surgical treatment of experimental peri-implantitis at implants with different surface characteristics using different anti-infective procedures. MATERIAL AND METHODS: Four implants with different surface characteristics (A: TiOblast, B: OsseoSpeed, C: AT-I, D: TiUnite) were installed in a randomized order in each side of the mandible in 6 labrador dogs 3 months after tooth extraction. Experimental peri-implantitis was induced 3 months later. Surgical treatment of peri-implantitis was performed. The implants were cleaned with gauze soaked in either saline (control) or chlorhexidine (test). Clinical and radiographical examinations were performed and microbiological samples were taken during a 6-month period after surgery. Biopsies were obtained and prepared for histological analysis. RESULTS: Clinical signs of soft tissue inflammation were reduced after surgical therapy in most test and control sites. While the analysis of bone level alterations in radiographs together with histological and microbiological assessments of resolution of peri-implantitis lesions failed to demonstrate statistically significant differences between test and control procedures, the evaluations disclosed significant differences between implant D and implants A, B and C on treatment outcome. CONCLUSION: It is suggested that (i) the local use of chlorhexidine has minor influence on treatment outcome, (ii) resolution of peri-implantitis following surgical treatment without the adjunctive use of local and systemic antimicrobial agents is possible and (iii) the results are influenced by implant surface characteristics.

Effect of cleansing of biofilm formed on titanium discs.

OBJECTIVES: To study the combined effect of mechanical and chemical cleansing on a 4-day biofilm grown intra-orally on titanium discs with different surface characteristics. MATERIAL AND METHODS: Twenty subjects used a splint with two metal plates in the upper jaw. Each plate was placed in the premolar-molar region and carried four titanium discs with four different surface characteristics (OsseoSpeed(™), TiOblast(™), experimental and turned surface). After 4 days of biofilm growth, the discs were cleaned mechanically and chemically with saline or chlorhexidine. Following cleansing, microbial samples were obtained and analysed by culture. The titanium discs were processed for scanning electron microscope (SEM) analysis. The experiment was repeated 3 days later using delmopinol or a mixture of essential oils during cleansing. RESULTS: The combination of mechanical and chemical cleansing was ineffective in complete biofilm removal from all four titanium discs. The microbiological analysis did not reveal any statistically significant differences between surface types or between cleaning agents regarding logarithmic mean counts of CFU for specific bacteria, aerobes, anaerobes or the TVC. Aerobes were more numerous than anaerobes on all surface types. The SEM analysis disclosed that the remaining biofilm on moderately rough surfaces (OsseoSpeed(™), TiOblast(™) and experimental) was complex and firmly attached, while the biofilm on turned surface had a pattern of spread bacteria forming less clusters. CONCLUSIONS: Cleansing may call for prolonged time of chemomechanical debridement and/or more effective disinfectants to suppress biofilms on dental implant surfaces.

Microbiota in experimental periodontitis and peri-implantitis in dogs.

AIM: To analyze the microbial profile around teeth and implants following ligature removal in experimental periodontitis and peri-implantitis in dogs. MATERIAL AND METHODS: Four implants with similar geometry and with two different surface characteristics (implant A: turned/implant B: TiUnite; NobelBiocare AB) were placed pairwise in the right side of the mandible 3 months after tooth extraction in five dogs. Experimental periodontitis and peri-implantitis were initiated 3 months later by ligature placement around implants and mandibular premolars and plaque formation. The ligatures were removed after 10 weeks. Microbial samples were obtained using paper points immediately after ligature removal, at 10 and 25 weeks after ligature removal. The microbiological analysis was performed by "checkerboard" DNA-DNA hybridization, including a panel of 16 bacterial species. RESULTS: The amount of bone loss that occurred during the period following ligature removal was significantly larger at implants with a modified surface than at implants with a turned surface and at teeth. The microbiological analysis revealed that the total bacterial load increased during the period following ligature removal and established an anaerobic Gram-negative microflora. CONCLUSION: It is suggested that the large variation in regard to the microbial profiles makes interpretation of a correlation between disease progression and microbial profiles difficult.

Bacterial markers vs. clinical markers to predict progression of chronic periodontitis: a 2-yr prospective observational study.

The aim of this study was to identify sites at risk for future progression, during 2 yr of maintenance, in patients with chronic periodontitis (CP), based on longitudinal clinical and microbiological monitoring. At baseline (2003), clinical and microbiological features were recorded in 50 patients with CP. Two microbial samples were obtained from each patient (one from a clinically healthy site and one from a periodontitis site) and these were analyzed using DNA-DNA hybridization involving 25 bacterial species. After non-surgical periodontal therapy, clinical and microbiological re-examinations were performed at the same or similar sites at 2 yr (2006) and 4 yr (2008) of maintenance. Plaque, bleeding on probing (BoP), and the number of sites with periodontitis (≥4 mm) and severe periodontitis (≥6 mm) all showed a significant decrease at 2 and 4 yr of maintenance after non-surgical intervention. Checkerboard analysis revealed that various bacteria with a high colonization score (≥3) corroborated the clinical findings of pathology at 2003, 2006, and 2008. Different clusters of bacteria, not just the 'red complex', were able to predict progression of chronic periodontitis during 2 yr of maintenance (2006-2008). Therefore, quantified bacterial markers (reflecting bacterial load) and the clinical markers BoP and periodontal probing depth show comparable prediction of future disease condition.

Malignant lymphoma in primary Sjögren's syndrome: an update on the pathogenesis and treatment.

OBJECTIVES: Sjögren's syndrome (SS), a chronic autoimmune disorder, particularly compromises the function of exocrine glands. Its association with lymphoma is well documented. Our aim was to systematically review the molecular, clinical, histopathologic, and therapeutic aspects of these SS-related malignant lymphoproliferations. METHODS: The literature was searched for original articles published between 1968 and 2012 focusing on the risk factors for lymphoma development in Sjögren's syndrome using MEDLINE and PubMed. The search terms we used were "Sjögren's syndrome," "lymphoma," and "risk factors." All papers identified were English-language, full-text papers. RESULTS: A low-grade marginal-zone lymphoma related to mucosa-associated lymphoid tissue is the commonest lymphoid neoplasia in SS. The majority of SS-associated lymphomas are characterized by localized stage, indolent clinical course, and recurrence in other extranodal sites. Although the transition from a chronic inflammatory condition to malignant lymphoma is a multistep process that is yet poorly understood, there is increasing evidence that chronic antigenic stimulation by an exoantigen or autoantigens plays an essential role in the development of SS-associated lymphoproliferation. CONCLUSIONS: This review discusses the pathogenetic aspects of lymphomagenesis in SS. Recent advances in the treatment of lymphoma in SS are also stated.

Peptostreptococcus canis sp. nov., isolated from subgingival plaque from canine oral cavity.

A polyphasic taxonomic study was performed on two strains of an unknown Gram-positive, asaccharolytic, nonspore-forming, obligately anaerobic coccus-shaped bacterium isolated from oral subgingival plaque of Labrador retriever dogs. Comparative 16S rRNA gene sequencing confirmed that these isolates were highly related to each other and formed a hitherto unknown linage within the clostridial rRNA XI cluster of organisms. Pairwise analysis demonstrated that the novel organism to be most closely related to members of the genus Peptostreptococcus with 16S rDNA gene sequence similarity values between 92.8% and 96.7%, respectively. The G + C DNA base composition was 30.8 mol% and the major cellular fatty acids included iso-C(14:0,) iso-C(16:0), and iso-C(16:0 DMA). Based on biochemical, chemotaxonomic, and phylogenetic evidence it is proposed that the unknown bacterium be classified as a new species, Peptostreptococcus canis sp. nov. The type strain is CCUG 57081(T).

A follow-up study of peri-implantitis cases after treatment.

AIM: The aim of this retrospective study was to follow patient cases in a longitudinal manner after peri-implantitis treatment. MATERIALS AND METHODS: Two hundred and eighty-one patient cases were selected consecutively from the archives of the Oral Microbiological Diagnostic Laboratory, Gothenburg, Sweden based on microbial analysis of bacterial samples taken from diseased implants. It was feasible to follow-up 245 patients after treatment for a period ranging from 9 months to 13 years. RESULTS: In 54.7% of the patients it was not feasible to arrest progression of peri-implantitis. Smoking and smoking dose were found to be significantly correlated to failure of peri-implantitis treatment (p<0.05). Early disease development was also significantly associated with failure (p<0.05). Bone plasty in conjunction to antibiotics during surgery was significantly associated with arrested lesions (p<0.05). In a multiple regression model disease development was the only independent variable to significantly predict the likelihood of treatment success. CONCLUSIONS: Peri-implant health may not be easy to establish, especially in cases that develop disease early. Homogenous treatment protocols rather than empirical treatment attempts should be adopted.

Autopathogenic correlation of periodontitis and rheumatoid arthritis.

Recently, a number of studies have pointed to a potential relationship between periodontitis (PO) and RA and vice versa. Both diseases are characterized by chronic inflammation, osseous destruction, damage of the supporting soft tissues, similar cellular immune responses and common immunogenetic findings. Although a definite, methodological report associating these diseases is missing from the literature, it is possible that both diseases share a common aetiopathogenic background. This background includes the post-translation modification citrullination, which guides the conversion of the amino acid arginine to citrulline in certain self-proteins, generating neo-epitope structures. This results in reduced self-tolerance, development of autoimmunity and the production of ACPAs. The current hypothesis suggests that certain oral bacteria induce the citrullination of proteins under the action of the enzyme peptidyl arginine deiminase (PAD), which exists in both Porphyromonas gingivalis and inflammatory cells. Antibodies against citrullinated proteins and peptides constitute a common serological finding in both RA and PO. The aim of this review is to map the immunological and serological profiles of PO, and to unveil the parameters that connect PO with the appearance of RA at clinical, prognostic and pathogenetic levels. Until now, there have been no reports sufficiently mapping the immunological profile of PO and defining its aetiopathogenic connection with RA, although a similarity between the immunological profile of PO and RA is highly expected.