Microbiota of Deciduous Endodontic Infections Analyzed by MDA and Checkerboard DNA-DNA Hybridization

Aims To evaluate the microbiota of endodontic infections in deciduous teeth by checkerboard DNA-DNA hybridization after uniform amplification of DNA in samples by multiple displacement amplification (MDA). Methodology Forty samples from the root canal system of deciduous teeth exhibiting pulp necrosis with or without radiographically detectable periradicular/interadicular bone resorption were collected and 32 were analyzed, with 3 individuals contributing 2 samples; these were MDA- amplified and analyzed by Checkerboard DNA-DNA hybridization for levels of 83 bacterial taxa. Two outcome measures were used: the percentage of teeth colonized by each species; and the mean proportion of each bacterial taxon present across all samples were computed. Results The mean amount of DNA in the samples prior to amplification was 5.2 (± 4.7) ng and 6.1 (± 2.3) μg after MDA. The mean number of species detected per sample was 19 (± 4) (range: 3–66) to the nearest whole number. The most prevalent taxa were Prevotella intermedia (96.9%), Neisseria mucosa (65.6%), Prevotella nigrescens (56.2%) and Tannerella forsythia (56.2%). Aggregatibacter (Haemophilus) aphrophilus and Helicobacter pylori were not detected. P. intermedia (10%), Prevotella tannerae (7%) and Prevotella nigrescens (4.3%) presented the highest mean proportions of the target species averaged across the positive samples. Conclusion Root canals of infected deciduous teeth had a diverse bacterial population. Prevotella sp were commonly found with P. intermedia, Prevotella tannerae and Prevotella nigrescens among the most prominent species detected

Prevalence and associated risk factors of latent tuberculosis infection among undergraduate and postgraduate dental students: A retrospective study

To estimate the prevalence of latent tuberculosis (TB) infection (LTBI) in Italian dental students exposed to the same occupational risks as dental health care personnel and to evaluate potential risk factors, a cross-sectional study was conducted on undergraduate and postgraduate students. After clinical evaluation, students were given a tuberculin skin test; in those found positive, an interferon-γ release assay (IGRA) was conducted. Of the 281 students enrolled, 10 were only TST positive; 8 were TST or/and IGRA positive. We found that participants testing positive at TST and/or IGRA, a group in which the risk of false LTBI positives is minimal, were older and had been studying longer. Although the prevalence of LTBI among dental students in our study was low, a risk of acquiring a work-related infection exists even in a country with a low incidence of TB. Thus, dental students should be screened to catch LTBI early on

Época de nascimento sobre a composição regional e tecidual da carcaça de cordeiros da raça Texel Birth season on regional and tissue carcass composition in Texel breed lambs

Foram avaliados os efeitos de épocas alternativas de nascimento sobre a composição regional e tecidual da carcaça em ovinos. Quarenta e nove cordeiros machos não-castrados da raça Texel, nascidos em duas épocas (agosto e novembro), foram mantidos em regime de pastagem e abatidos com média de idade de 129 e 164 dias, respectivamente. Previamente aos abates foi feita a avaliação da produção forrageira do campo pelo método Botanal. Foram verificadas melhores condições forrageiras para os cordeiros nascidos em agosto, que apresentaram maior peso e proporção na maioria dos cortes, assim como menor proporção de músculo na paleta e perna; apresentando maior conteúdo de tecido adiposo na maioria dos cortes da carcaça. Para os cordeiros nascidos em novembro, ocorreu maior relação músculo:gordura e músculo:osso na paleta e na perna, assim como maior relação músculo:gordura no costilhar. As condições nutricionais são responsáveis pelas diferenças nos pesos e rendimentos dos cortes, assim como na composição tecidual da carcaça, em cordeiros mantidos em regime de pasto, viabilizando o uso de época alternativa de nascimentos para incrementar a oferta de animais para o abate.<br>The effect of alternative birth season on regional and tissue carcass composition of sheep was evaluated. Forty nine (49) Texel intact male lambs, born in two seasons (August and November), were kept under grazing and slaughtered with an average age of 129 and 164 days, respectively. Prior to slaughter forage production was measured using Botanal method. Lambs born in August had more favorable forage conditions, showing higher body weight and proportion in the majority of cuts, as well as lower proportion of shoulder and leg muscles showing higher adipose tissue content in the majority of carcass cuts. For lambs born in November, a higher muscle:fat and muscle:bone rate in shoulder and leg, as well as a higher ribcut muscle:fat rate. Nutritional conditions are responsible for differences in weights and cuts yields, as well as for the tissue carcass composition, in lambs maintained under grazing regime, making feasible the use of alternative birth periods to increase animal offer for slaughter