Residual bacteriome after chemomechanical preparation of root canals in primary and secondary infections

Secondary infections may be linked to the presence of residual microorganisms within dental root canals. The purpose of this study was to investigate the bacterial composition of primary and secondary root canal infections, before and after chemomechanical treatment. Samples were collected before chemomechanical preparation (S1) and prior obturation (S2) from 19 subjects (10 primary and 9 secondary infections). DNA was extracted and the V3/V4 region of the 16SrRNA gene was amplified using the 347F/803R primers and paired-end sequenced using the Illumina MiSeq instrument. Sequencing analysis yielded partial 16S rRNA gene sequences that were taxonomically classified into 10 phyla and 143 genera. The most prevalent phyla in S1 and S2 samples were found to be Firmicutes and Bacteroides, however, when comparing between sample groups, Proteobacteria seem to have been enriched in secondary infections. The dominant genera in the primary S1 samples were Bacillus, Streptococcus and Prevotella while Bacillus, Streptococcus and Selenomonas dominated the secondary infection S1 samples. Bacillus and Marinilactibacillus were the most dominant genera in primary and secondary S2. The mean number of OTUs per sample was 32,656 (±12,124 SD) and 37,113 (± 16,994 SD) in S1 and S2 samples, respectively. Alpha and Beta diversities presented the same pattern within samples from both groups. Great inter-individual variations in the bacterial composition of the root canal biofilms were observed. There was no difference in the bacterial composition before and after treatment, although some genera survived and seems to be part of a residual microbiome. Our findings revealed a high diversity of the bacterial communities present in root canal infections after chemomechanical treatment, although the majority of the taxa detected were in low abundance

Equipes de referência e apoio especializado matricial: um ensaio sobre a reorganização do trabalho em saúde Local reference teams and specialized matrix support: an essay about reorganizing work in health services

Este artigo propõe um novo arranjo organizacional para o trabalho em saúde. É desenvolvido e ampliado o conceito de equipe de referência - proposto e experimentado pelo autor desde 1989. É também reelaborado o conceito de organização matricial do trabalho, invertendo-se em relação ao esquema original o que seria permanente e aquilo que seria transitório (recorte matricial) nos serviços de saúde. São também apresentadas considerações teóricas que autorizam e justificam a construção desta nova proposta.<br>A new organizational settlement for the work in the health services is proposed. An original concept is developed to defining the profile of a local reference team, as created and experimented by the author sice 1989. The classical organizational structure in matrix is realaborated to encompass this new approach. Theoretical consideration that subsidize and give basis to building this new proposal are presented

Measuring and interpreting transposable element expression

International audienceTransposable elements (TEs) are insertional mutagens that contribute greatly to the plasticity of eukaryotic genomes, influencing the evolution and adaptation of species as well as physiology or disease in individuals. Measuring TE expression helps to understand not only when and where TE mobilization can occur, but also how this process alters gene expression, chromatin accessibility or cellular signalling pathways. Although genome-wide gene expression assays such as RNA-sequencing include transposon-derived transcripts, the majority of computational analytical tools discard or misinterpret TE-derived reads. Emerging approaches are improving the identification of expressed TE loci and helping to discriminate TE transcripts that permit TE mobilization from gene-TE chimeric transcripts or pervasive transcription. Here, we review the main challenges associated with the detection of TE expression, including mappability, insertional and internal sequence polymorphisms, and the diversity of the TE transcriptional landscape, as well as the different experimental and computational strategies to solve them