Aims To estimate the species richness of gram-positive coccoid morphotypes (GPCM) from untreated and treated root canals of teeth with periapical disease, using partial 16S rRNA gene sequences and biochemical properties for identification. To further characterise the isolates by antibiotic sensitivity profiles and a subset of isolates by 16S-23S intergenic amplicon patterns. Methodology 195 isolates from 20 teeth (GPCM: 117 - untreated teeth; 78 - treated teeth) were investigated. 16S rDNA obtained from all isolates using universal primers was partially sequenced and the sequences aligned with those in databases using RDP and BLAST searches. The process of identity determination was analysed. Biochemical, commercial enzyme, and MIC tests by agar dilution and E-test (8 antibiotics) were also performed. Streptococcus, Staphylococcus, Enterococcus and Lactobacillus strains were evaluated by 16S-23S intergenic amplicon profile. The relatedness of like-strains was compared by: phylogenetic tree reconstruction using sequence data; and dendrograms using biochemical data. The putative identities from different approaches were compared. Results DNA concentration, PCR and sequencing primers, PCR protocol and origin of isolates ("untreated" or "treated") influenced sequence acquisition. The 16S rRNA sequence search method (RDP/BLAST), together with treated/untreated tooth origin, influenced putative strain identity. Thirty-eight percent of "untreated" isolates and half the "treated" isolates were identified with ? 98% sequence homology; the majority of the rest varied between 93%-97%. The 16S-23S intergenic amplicon patterns helped confirm genus designation and strain variation. Biochemical profiles were graded "unacceptable" in 38% of all isolates; a higher proportion was from treated teeth (46%:32%). Biochemical identities matched with 16S rRNA identities to genus level in 72% of isolates, to species level in 45%, and the rest did not match. MICs from agar dilution and E-test were within 2 dilutions in 90% of tests. Frequency distributions of MICs showed NCCLS (2003) breakpoint values to give reliable interpretive categories. Thirty-eight percent of isolates showed resistance, which was more common amongst "treated" isolates (53%:26%). Antibiotic resistance helped confirm or query identities and inform strain variation. Conclusions The 16S rRNA gene sequence, 16S-23S intergenic amplicon patterns and biochemical and MIC profiles gave different perspectives on isolates. Each approach provided accumulative evidence of subspecies strain variation and that strains colonising treated teeth may be influenced by treatment history.

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Antibiotic-resistant bacteria present a serious public health threat and studies investigating the prevalence of antibiotic-resistant bacteria and the genes encoding for antibiotic resistance (GEAR) are essential. Such studies help us to understand how antibiotic-resistant bacteria and GEAR are obtained, transferred and maintained within a population. The aim of this study was to identify the prevalence and maintenance of antibiotic-resistant bacteria in the oral microbiota of children aged 4-6 years who had not previously taken antibiotics. Bacteria resistant to penicillin, ampicillin, tetracycline and erythromycin were widespread among the children studied. Tetracycline-resistant bacteria were found in 98% of the children sampled and the tetracycline resistance determinants most responsible for this resistance were tet(M) and tet(W). The tetracycline-resistant bacteria were maintained within 15 children over a period of twelve months. In three of these children the tet(M) gene was found to persist in a variety of genera and this was found to be contained within a Tn9/6-like element by Southern blot analysis. The tetracycline resistance determinant tet(S) was found for the first time in Streptococcus intermedius . It was found to be transferable to Enterococcus faecalis and other Streptococcus spp. by filter matings. The tet(S) gene was shown to be present on a novel Tn9/f5-like element designated Tn97r5S. The similarities between Tn916 and Tn976S included the presence of conjugative and excision and integration modules. However the tet(M) in Tn976 had been completely replaced by tet(S) in Tn9/f5S. The gene tet(32) was also found for the first time in Streptococcus parasanguinis and Eubacterium saburreum, previously it had been found in a human colonic bacterium K10. The upstream region of the oral tet(32) gene in E. saburreum 41.2T.2 was found to be more closely related to upstream sequences of tet(W) in Roseburia sp. A2-123, upstream sequences of tet(W) within TnB1230 (originally isolated from Butyrivibrio fibrisolvens ) and orf!4, orf25 and orf26 from Tn5397. This work provides further evidence that antibiotic-resistant bacteria are prevalent in the oral microbiota of children and that the genes responsible, especially those encoding resistance to tetracycline, can be maintained in the oral microbiota even when the children have not been directly exposed to antibiotics. These findings show that tetracycline resistance determinants can be mosaic in structure and can be easily transferred due to their containment within conjugative transposons. Such elements then undergo evolutionary changes, whereby recombination of the conjugative transposon modules result in new genetic elements.

Background: The placement of removable dental prostheses produces significant changes in the oral environment that may lead to adverse effects on the integrity of the oral tissues. Denture-induced candidosis, caused by candidal infection of the palatal mucosa, is the most frequent complication (40 %) in removable denture wearers. It predominantly affects immunosuppressed and medically compromised patients. In these high-risk patients the oral cavity may provide a source for Candida causing systemic infection. Oral candidosis has become a significant challenge in patients with persisting risk factors and a recurrent need for antifungal treatment. In addition, denture-induced candidosis is a mixed biofilm infection which provides multiple challenges for its management. Moreover, the persistent fungal colonisation on the fitting surfaces of denture often leads to cross infection and recurrence of mucosal lesions. These considerations highlight the clear need for new effective antifungal treatment modalities.Aims: The aims of this project were to establish a polymeric delivery device based on denture base lining polymer, poly (ethyl methacrylate) and tetrahydrofurfuryl methacrylate (PEM/THFM), for sustained delivery of antifungal agents [chlorhexidine (CHX) and fluconazole (FLU)], for the use in the treatment of denture-induced candidosis and to test the serviceability of the lining under investigation.Methods: A broth microdilution method was used to assess the spectrum of activity of the antifungal agents (CHX powder and FLU powder in two formulations pure and from capsules) against wide range of Candida species. Bioassay method and spectrophotometry were used to evaluate the efficiency of the PEM/THFM denture liner to release the impregnated antifungal agents and to quantify the released concentrations. Bioassay, time-kill studies and biofilm assays were used to verify the antifungal activity of the released antifungal agents. Shear bond test, water absorption, colorimetery and Fourier Transform Infrared Spectroscopy were used to test clinically important physical and mechanical properties for the impregnated liner.Results: It was found that CHX has broad-spectrum antifungal activity also among Candida species highly resistant to FLU. Both CHX and FLU became readily leached from PEM/THFM polymer up to 4 weeks in microbiologically effective concentrations. CHX demonstrated superior antifungal efficacy against planktonic and biofilm lifestyle of Candida compared to FLU. Findings show that the impregnation with antifungal agents has affected all tested properties (shear bond strength, water absorption, degree of conversion and colour stability) but these changes are comparable to other long-term lining materials and are within acceptable ranges.Conclusions: These findings indicate the feasibility of introducing an efficient treatment modality for candidal infections, especially denture-induced candidosis. A polymeric system containing CHX or FLU could assume a very promising treatment option as the drug is effective and directed to the site of pathology. Moreover, the distinct efficacy of CHX against C. albicans biofilms is a promising outcome to overcome the side effects of conventional antifungal agents and their reduced efficacy against biofilm formation.

Orientadora: Profª. Drª. Luciana Reichert Assunção Zanon / Coorientador: Prof. Dr. Fabian Calixto Fraiz / Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Odontologia. Defesa: Curitiba, 2016 / Inclui referências : f. 36-39;41-44 / Área de concentração / Resumo: A doença celíaca é considerada uma enteropatia imunomediata induzida pela ingestão de glúten na dieta e está relacionada a padrões genéticos com características epidemiológicas diferentes em populações específicas. Esta pesquisa analisou a ocorrência e características de manifestações orais em indivíduos sul brasileiros com a doença celíaca (DC). Estudo transversal envolvendo 40 pacientes com DC assistidos no ambulatório de gastropediatria do Hospital de Clínicas da Universidade Federal do Paraná, Curitiba, Brasil. Os indivíduos foram classificados de acordo com o tipo de DC em clássica, não clássica e assintomática. O grupo controle (n=40) sem o diagnóstico da doença, pareados por idade. Os participantes ou seus responsáveis responderam a um questionário pré-testado, com questões relacionadas ao histórico médico e odontológico, frequência de escovação e de consumo de alimentos com potencial cariogênico. Clinicamente, avaliou-se em dentes decíduos e permanentes a presença de defeitos de desenvolvimentos de esmalte (DDE) segundo a classificação de AINE e cárie dentária segundo critérios da OMS por um examinador calibrado (kappa?0,826). Presença de ulcerações aftosas recorrentes (UAR) e boca seca foi obtida por relato dos pacientes. Os dados foram analisados por meio de testes não paramétricos (?=0,05). A mediana da idade dos participantes foi 16,50 e as idades variaram entre 5 e 34 anos. Pacientes celíacos apresentaram 2,83 vezes a chance de ocorrência de DDE que o grupo controle (P=0,045). Quanto ao relato de boca seca, indivíduos com DC mostraram 9,15 vezes a chance desta alteração que no grupo controle (P=0,002). Não houve diferença entre os grupos para a ocorrência de UAR e experiência de cárie não tratada. Houve uma tendência de maior presença de DDE entre celíacos com a forma clássica da doença (P=0,054). DDE do tipo específico, ou seja, com o envolvimento dos quatro quadrantes dentários, foi significativamente maior em indivíduos com DC (P=0,048). Do total de 1962 dentes permanentes avaliados, 59 apresentaram DDE, sendo 71,8% dos casos em pacientes celíacos (P=0,001), com predominância nos molares permanentes (P=0,009). Conclui-se que DC aumentou a chance de desenvolvimento de DDE e sensação de boca seca. O exame clínico bucal é uma ferramenta importante no diagnóstico e monitoramento de casos de DC. Palavras-chave: doença celíaca, hipoplasia do esmalte, manifestações bucais / Abstract: Celiac disease (CD) is considered a imunomediata enteropathy induced by ingestion of gluten in the diet and is related to genetic patterns with different epidemiological characteristics in specific populations. This research examined the occurrence and characteristics of oral manifestations in Brazilian southern individuals with CD. Crosssectional study involving 40 patients with CD assisted at the Pediatric Gastroenterology Clinic at Clinical Hospital of the Federal University of Paraná, Curitiba, Brazil. The subjects were classified according to the type of DC classical, non-classical and asymptomatic. The control group (n = 40) without the diagnosis of the disease, age-matched. The participants or their guardians answered a tested questionnaire with questions related to medical and dental history, frequency of toothbrushing and consumption of food with cariogenic potential. Clinically evaluated in primary and permanente teeth the presence of dental enamel defects (DED) according to the classification of AINE and dental caries according to WHO criteria by a calibrated examiner (kappa?0,826). The presence of recurrent aphthous ulcerations (RAU) and dry mouth was obtained from the reporting of the patients. Data were analyzed using nonparametric tests (? = 0.05). The median age of participants was 16.50 and the ages ranged from 5 to 34 years. Patients with CD had 2.83 times the chance of occureence of DED than the control group (P = 0.045). As for the dry mouth report, individuals with AD showed 9.15 times the chance of this alteration in the control group (P = 0.002). There was no difference between groups for the occurrence of RAU and untreated caries experience. There was a trend toward greater presence of DED between celiacs with the classic form of the disease (P = 0.054). DED specific type, in other words, with the involvement of the four dental quadrants was significantly higher in patients with CD (P = 0.048). Of the total of 1962 evaluated permanent teeth, 59 presented DED, and in 71.8% of the cases was in patients with CD (P = 0.001), especially in permanent molars (P = 0.009). It is concluded that CD increased the chance of DED and dry mouth. The oral clinical examination is an important tool in the diagnosis and monitoring of cases of CD. Key-words: celiac disease, dental enamel hypoplasia, oral manifestations

Bibliography: p. 519-534. / xix, 534 p. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates the social impact of oral disease among older adults in South Australia. / Thesis (Ph.D.)--University of Adelaide, Dept. of Dentistry, 1993