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- Role of Porphyromonas gingivalis gingipains in multi-species biofilm formation. [JOURNAL ARTICLE]
- BMC Microbiol 2014 Oct 2; 14(1):258.
BackgroundPeriodontal diseases are polymicrobial diseases that cause the inflammatory destruction of the tooth-supporting (periodontal) tissues. Their initiation is attributed to the formation of subgingival biofilms that stimulate a cascade of chronic inflammatory reactions by the affected tissue. The Gram-negative anaerobes Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola are commonly found as part of the microbiota of subgingival biofilms, and they are associated with the occurrence and severity of the disease. P. gingivalis expresses several virulence factors that may support its survival, regulate its communication with other species in the biofilm, or modulate the inflammatory response of the colonized host tissue. The most prominent of these virulence factors are the gingipains, which are a set of cysteine proteinases (either Arg-specific or Lys-specific). The role of gingipains in the biofilm-forming capacity of P. gingivalis is barely investigated. Hence, this in vitro study employed a biofilm model consisting of 10 ¿subgingival¿ bacterial species, incorporating either a wild-type P. gingivalis strain or its derivative Lys-gingipain and Arg-gingipan isogenic mutants, in order to evaluate quantitative and qualitative changes in biofilm composition.ResultsFollowing 64 h of biofilm growth, the levels of all 10 species were quantified by fluorescence in situ hybridization or immunofluorescence. The wild-type and the two gingipain-deficient P. gingivalis strains exhibited similar growth in their corresponding biofilms. Among the remaining nine species, only the numbers of T. forsythia were significantly reduced, and only when the Lys-gingipain mutant was present in the biofilm. When evaluating the structure of the biofilm by confocal laser scanning microscopy, the most prominent observation was a shift in the spatial arrangement of T. denticola, in the presence of P. gingivalis Arg-gingipain mutant.ConclusionsThe gingipains of P. gingivalis may qualitatively and quantitatively affect composition of polymicrobial biofilms. The present experimental model reveals interdependency between the gingipains of P. gingivalis and T. forsythia or T. denticola.
- Screening and Development of DNA Aptamers Specific to Several Oral Pathogens. [JOURNAL ARTICLE]
- J Microbiol Biotechnol 2014 Oct 1.
Aptamers are composed of single stranded oilgonucleotides which can selectively bind desired molecules. In 1980s, Thomas Cech reported that RNA or DNA could play as not only a genetic messenger but also a catalyst in metabolic pathways. RNA aptamers (average sizes 40-50 bp) are smaller than antibodies and have strong binding capacities to target molecules similar to antigen-antibody interactions. Once an aptamer was selected, it can be readily produced in large quantities at low cost. The objectives of this study are to screen and develop aptamers specific to oral pathogens such as Porphyromonas gingivalis, Treponema denticola and Streptococcus mutans. Bacterial cell pellet was fixed with formaldehyde as a target molecule for the screening of aptamer. SELEX method was used for the screening of aptamers and modified-Western blot analysis was used to verify their specificities. Through SELEX, 40 kinds of aptamers were selected and the specificity of the aptamers to the bacterial cells was confirmed by modified-Western blot analysis. Through SELEX method, 40 aptamers that specifically bind to oral pathogens were screened and isolated. The aptamers showed the possibility as an effective candidate for the detection agents of oral infections.
- Polymerase chain reaction as a prospect for the early diagnosis and prediction of periodontal diseases in adolescents. [JOURNAL ARTICLE]
- Eur Arch Paediatr Dent 2014 Sep 30.
This study was to determine the markers representative of pathogenic periodontal microflora [Prevotella intermedia (P.i), Tannerella forsythia (T.f) [Bacteroides forsythus], Treponema denticola (T.d), Actinobacillus actinomycetemcomitans (A.a), Porphyromonas gingivalis (P.g)] in the dental plaque of adolescents with various degrees of severity of periodontium inflammation.Forty-patients aged 15-16 years of age were examined using PMA, CPI and Green-Vermillion indices (Müller 2001). The hygiene status of each patient was also determined using Durr Dental's Vista Proof intraoral camera (Germany). The polymerase chain reaction (PCR) was performed using a Biometra Thermocycler to detect DNA of pathogenic periodontal bacteria in dental plaque.All marker microorganisms (P.i. + T.f. + T.d. + A.a. + P.g.) were identified in patients diagnosed with periodontitis in dental plaque. A direct correlation between the level of oral hygiene and the severity of the pathological process in it was determined. It was found that the increase in the severity of the disease was accompanied by increased pathogenic periodontal microflora in dental plaque.Identification of periodontal pathogens in dental plaque by PCR greatly enhances the early diagnosis of Cronic cattaral gingivitis (CCG) risk factors in adolescents, and allows for detailed analysis of the relation between each factor and severity of the process. This method may be used for the diagnosis of periodontal diseases, prediction of their future course, and reasonable choice of antimicrobial therapy.
- Presentación del estudio "Links" de hombres que tienes sexo con hombres en Buenos Aires, Argentina. [JOURNAL ARTICLE]
- Actual SIDA 2011 Mar; 19(71):21-25.
Estudios previos en Buenos Aires reportaron altas prevalencias de HIV entre HSH, con valores que oscilan entre 9 y 14% durante casi 10 años de continuo testeo. El objetivo principal de este estudio fue la evaluación de factores relacionados al comportamiento de alto riesgo para transmisión del HIV entre HSH entre los que se incluyen el conocimiento y factores emocionales, socioculturales y ambientales. Por otro lado se realizó la estimación de prevalencia e incidencia de HIV utilizando RDS (Respondent Driven Sampling), así como la presencia de otras infecciones de transmisión sexual. Por último se evaluaron los hábitos de testeo para HIV indagando que factores facilitan o impiden su realización. El estudio constó de dos fases, en primer lugar una fase cualitativa y posteriormente una fase cuantitativa con una duración total de 4 años y medio. Durante la fase cualitativa se realizaron 44 entrevistas individuales en profundidad, 8 grupos focales y 10 observaciones etnográficas (hoteles, baños públicos ("teteras"), cines pornográficos, fiestas privadas, dark rooms y discotecas). Durante la fase cuantitativa del estudio se realizó el reclutamiento de 500 participantes que provinieron de la Ciudad Autónoma de Buenos Aires, así como del Gran Buenos Aires. El reclutamiento se comenzó con 16 participantes llamados semillas. Se realizó el diagnóstico de infección por HIV, hepatitis B y C (HBV y HCV), Treponema pallidum, Virus Papiloma Humano (HPV) y Chlamidias. La colaboración establecida entre los grupos de trabajo enfocados en áreas diversas posibilitó el abordaje conjunto de nuevas estrategias de investigación antes no exploradas en nuestro país. Los resultados más relevantes de esta investigación serán progresivamente publicados en sucesivos números de Actualizaciones en SIDA.
- Acute Cranial Neuropathies Heralding Neurosyphilis in Human Immunodeficiency Virus-Infected Patient. [JOURNAL ARTICLE]
- Am J Case Rep 2014.:411-415.
Background Symptomatic early neurosyphilis with isolated acute multiple cranial nerves palsy as initial manifestation of HIV infection is very rare. It is caused by direct invasion of the central nervous system by the spirochete Treponema pallidum. Case Report A 31-year-old African-American homosexual man presented with bilateral hearing loss, constant vertigo, intermittent horizontal diplopia, and bilateral facial droop, which was associated with occipital headache without fever. Neurological examination revealed bilateral vestibulocochlear and facial nerve palsy. On brain magnetic resonance imaging (MRI) before and after administration of gadolinium, he was found to have extensive isolated basilar meningeal enhancement involving the midbrain, pons along the seven and eight nerves complex bilaterally, consistent with basal meningoencephalitis. Conclusions Neurosyphilis can present as initial manifestation of HIV infection with early involvement of basal meninges and cranial nerves. It is important to understand that neurosyphilis is still a significant disease with complex neurological presentation. Early diagnosis and treatment of neurosyphilis is crucial due to potential persistent disabilities that can be easily treated or even prevented.
- An unusual cause of an ankle mass. [JOURNAL ARTICLE]
- BMJ Case Rep 2014.
We report the case of a patient who presented with a 7-year history of a mass over the medial aspect of his right ankle, which had been gradually increasing in size. He had given up his occupation as a bus driver due to decreased movement of his ankle. An initial diagnosis of endemic syphilis was made after treponemal antibody and treponema pallidum particle agglutination tests were positive. However, following surgical debulking, cultures grew Fusarium solani and the diagnosis was changed to eumycetoma. He received prolonged treatment with antifungal agents and at 18 months follow-up remains well.
- Association between Polycystic Ovary Syndrome, Oral Microbiota and Systemic Antibody Responses. [Journal Article]
- PLoS One 2014; 9(9):e108074.
Polycystic ovary syndrome (PCOS) is a hormonal disorder of women that not only is the leading cause of infertility but also shows a reciprocal link with oral health. This study aimed to investigate the hypothesis that the levels of putative periodontal pathogens in saliva and their antibody response in serum are elevated in PCOS, compared to systemic health. A total of 125 women were included in four groups; 45 women with PCOS and healthy periodontium, 35 women with PCOS and gingivitis, 25 systemically and periodontally healthy women, 20 systemically healthy women with gingivitis. Salivary levels of seven putative periodontal pathogens were analyzed by quantitative real-time polymerase chain reaction and serum antibody levels were analyzed by ELISA. In women with PCOS, salivary Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus oralis and Tannerella forsythia levels were higher than matched systemically healthy women, particularly in the case of gingivitis. Aggregatibacter actinomycetemcomitans and Treponema denticola levels were similar among study groups. The presence of PCOS also enhanced P. gingivalis, Prevotella intermedia and S. oralis serum antibody levels, when gingivitis was also present. Gingival inflammation correlated positively with levels of the studied taxa in saliva, particularly in PCOS. The presence of P. gingivalis and F. nucleatum in saliva also exhibited a strong positive correlation with the corresponding serum antibody levels. In conclusion, as an underlying systemic endocrine condition, PCOS may quantitatively affect the composition of oral microbiota and the raised systemic response to selective members of this microbial community, exerting a confounding role in resultant gingival inflammation and periodontal health. The most consistent effect appeared to be exerted on P. gingivalis.
- Coexistence of congenital syphilis and cytomegalovirus infection: a case report. [Journal Article]
- Acta Dermatovenerol Croat 2014 Sep; 22(3):215-7.
A 22-year-old pregnant woman with an intravenous drug abuse habit delivered a girl in the 26th gestational week with a fetal length and weight of 38 cm/990 g (pc. 75-91). She did not participate in prenatal care that included screening for congenital diseases, syphilis, and human immunodeficiency virus (HIV) infection during the pregnancy. Laboratory examinations revealed positive rapid plasma reagin (RPR) (1:128), Treponema pallidum particle agglutination assay (TPPA) and TpELISA results. Immediately before delivery, labial herpes simplex virus-1 (HSV-1), Streptococcus agalactiae, and genital yeast infections were detected. Hepatitis B surface antigen (HbsAG), HIV, and hepatitis C virus (HCV) serology remained negative. The preterm and immature newborn girl had mild jaundice, minimal edema, and gluteal hematomas with petechiae. The liver and spleen were extremely enlarged (reaching the plevic bones). Increased muscle tone and rigid elbow, knee, and hip joints were found (Figures 1, 2). Additionally, X-ray examination detected multiple jejunal atresia. Brainstem evoked response audiometry ruled out hearing loss. In laboratory investigations anisocytosis, thrombocytopenia, elevated liver enzymes (ASAT: 3850 U/L, ALAT: 558 U/L, GGT: 292 U/L, ALP: 436 U/L), elevated lactate dehydrogenase (LDH) (38180 mmol/L), and creatinine kinase (CK) (7.1 U/L) with elevated bilirubin levels (87.9 μmol/L) were found. In microbiology investigations a high CMV virus number was detected using a quantitative real-time polymerase chain reaction (PCR) method from the urine and blood. Syphilis serology was positive (RPR: 1:16 positive, TPPA, TpELISA, and T. pallidum IgM immunoblot positive). HSV PCR (in the oral mucosa, conjunctiva, and blood) remained negative. Intravenous penicillin-G (100.000 IU/kg/dose for 10 days) therapy was administered. Intravenous ganciclovir was started, but was discontinued after 2 weeks because of progressive thrombocytopenia and elevating liver enzymes. The newborn underwent transfusion due to anemia and extreme thrombocytopenia. Blue light therapy was administered for 3 days because of jaundice. The multiple jejunal atresia was treated by operation (terminoterminal jejuno-jejunostomia and ileal stricturaplastica) in the Semmelweis University Pediatrics Clinic. At the time of writing this report, the girl was 2 months old, growing and developing; her intestinal passage is satisfactory, but the liver enzymes are extremely high due to the CMV infection. Congenital syphilis and congenital CMV are preventable diseases, but they are still the most common causes of perinatal mortality and morbidity worldwide (4,5). Intravenous drug users and mothers of low socioeconomic status belong to the highest risk groups for vertical transmission of infections. Congenital syphilis may induce jaundice, hepatosplenomegaly, wrinkled skin, thrombocytopenia, and anemia, with symptoms that are clinically similar to congenital CMV infection, making the differential diagnosis difficult (1,5,6). Although syphilis screening tests are mandatory in the first trimester of pregnancy in Hungary, at least one congenital syphilis case was observed yearly since the mid-nineties. Therefore, a second syphilis test is strongly recommended after the 28th gestational week or before delivery, particularly in high risk groups (7). The prenatal diagnosis of fetal CMV infection is based on amniocentesis in the 21st gestational week, which is a risky and non-standard method. The widely used ultrasonography examination often yields a uncertain diagnosis (8). Intravenous penicilline-G is effective treatment for congenital syphilis, but there is no gold standard therapy for CMV infection. Treatment with ganciclovir may prevent hearing loss later in life, but it has several severe side effects (neutropenia, anemia, thrombocytopenia, elevated liver enzymes) (9). Furthermore, studies on the effect of prolonged valganciclovir therapy are still ongoing (10). Prevention is the most effective method of reducing the prevalence of congenital CMV: pregnant women should avoid contact with the saliva of young children. In our case, the mother of the newborn belonged to a high risk group and did not participate in the prenatal caring system; mandatory screening tests were not done, so congenital infections were diagnosed only at delivery. The treatment for congenital syphilis was effective, and resulted in decrease of RPR titers. Most of the clinical symptoms did not improve, and the liver enzymes were continuously increased, indicating that CMV infection was a major contributor in clinical manifestation. Further follow up is needed to evaluate the radiological findings of long bones. Our case draws attention to the importance of early and effective prenatal diagnosis, adequate treatment of prenatal infectious diseases, and the necessity of a multidisciplinary approach to congenital infections.
- Bacterial community composition of chronic periodontitis and novel oral sampling sites for detecting disease indicators. [Journal Article]
- Microbiome 2014.:32.
Periodontitis is an infectious and inflammatory disease of polymicrobial etiology that can lead to the destruction of bones and tissues that support the teeth. The management of chronic periodontitis (CP) relies heavily on elimination or at least control of known pathogenic consortia associated with the disease. Until now, microbial plaque obtained from the subgingival (SubG) sites has been the primary focus for bacterial community analysis using deep sequencing. In addition to the use of SubG plaque, here, we investigated whether plaque obtained from supragingival (SupG) and tongue dorsum sites can serve as alternatives for monitoring CP-associated bacterial biomarkers.Using SubG, SupG, and tongue plaque DNA from 11 healthy and 13 diseased subjects, we sequenced V3 regions (approximately 200 bases) of the 16S rRNA gene using Illumina sequencing. After quality filtering, approximately 4.1 million sequences were collapsed into operational taxonomic units (OTUs; sequence identity cutoff of >97%) that were classified to a total of 19 phyla spanning 114 genera. Bacterial community diversity and overall composition was not affected by health or disease, and multiresponse permutation procedure (MRPP) on Bray-Curtis distance measures only supported weakly distinct bacterial communities in SubG and tongue plaque depending on health or disease status (P < 0.05). Nonetheless, in SubG and tongue sites, the relative abundance of Firmicutes was increased significantly from health to disease and members of Synergistetes were found in higher abundance across all sites in disease. Taxa indicative of CP were identified in all three locations (for example, Treponema denticola, Porphyromonas gingivalis, Synergistes oral taxa 362 and 363).For the first time, this study demonstrates that SupG and tongue dorsum plaque can serve as alternative sources for detecting and enumerating known and novel bacterial biomarkers of CP. This finding is clinically important because, in contrast with SubG sampling that requires trained professionals, obtaining plaque from SupG and tongue sites is convenient and minimally-invasive and offers a novel means to track CP-biomarker organisms during treatment outcome monitoring.
- Evaluation of a rapid diagnostic test for yaws infection in a community surveillance setting. [Journal Article]
- PLoS Negl Trop Dis 2014 Sep; 8(9):e3156.
Yaws is a non-venereal treponemal infection caused by Treponema pallidum ssp. pertenue. The WHO has launched a worldwide control programme, which aims to eradicate yaws by 2020. The development of a rapid diagnostic test (RDT) for serological diagnosis in the isolated communities affected by yaws is a key requirement for the successful implementation of the WHO strategy. We conducted a study to evaluate the utility of the DPP test in screening for yaws, utilizing samples collected as part of a community prevalence survey conducted in the Solomon Islands. 415 serum samples were tested using both traditional syphilis serology (TPPA and quantitative RPR) and the Chembio DPP Syphilis Screen and Confirm RDT. We calculated the sensitivity and specificity of the RDT as compared to gold standard serology. The sensitivity of the RDT against TPPA was 58.5% and the specificity was 97.6%. The sensitivity of the RDT against RPR was 41.7% and the specificity was 95.2%. The sensitivity of the DPP was strongly related to the RPR titre with a sensitivity of 92.0% for an RPR titre of >1/16. Wider access to DPP testing would improve our understanding of worldwide yaws case reporting and the test may play a key role in assessing patients presenting with yaws like lesions in a post-mass drug administration (MDA) setting.