RESUMO
φEf11 is a temperate Siphoviridae bacteriophage isolated by induction from a lysogenic Enterococcus faecalis strain. The φEf11 DNA was completely sequenced and found to be 42,822 bp in length, with a G+C mol% of 34.4%. Genome analysis revealed 65 ORFs, accounting for 92.8% of the DNA content. All except for seven of the ORFs displayed sequence similarities to previously characterized proteins. The genes were arranged in functional modules, organized similar to that of several other phages of low GC Gram-positive bacteria; however, the number and arrangement of lysis-related genes were atypical of these bacteriophages. A 159 bp noncoding region between predicted cI and cro genes is highly similar to the functionally characterized early promoter region of lactococcal temperate phage TP901-1, and possessed a predicted stem-loop structure in between predicted P(L) and P(R) promoters, suggesting a novel mechanism of repression of these two bacteriophages from the λ paradigm. Comparison with all available phage and predicted prophage genomes revealed that the φEf11 genome displays unique features, suggesting that φEf11 may be a novel member of a larger family of temperate prophages that also includes lactococcal phages. Trees based on the blast score ratio grouped this family by tail fiber similarity, suggesting that these trees are useful for identifying phages with similar tail fibers.
Assuntos
DNA Viral/química , DNA Viral/genética , Enterococcus faecalis/virologia , Genoma Viral , Prófagos/genética , Composição de Bases , Análise por Conglomerados , Ordem dos Genes , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Filogenia , Regiões Promotoras Genéticas , Prófagos/isolamento & purificação , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , SinteniaRESUMO
Controversy remains regarding the relative toxicity versus inertness of endodontic filling materials, including gutta-percha, in vital tissues.We discuss reaction to and possible toxicity of gutta-percha and sealers and present 2 cases of symptomatic chronic inflammatory reaction where gutta-percha and associated filling materials were found to have extruded past the confinement of the root structure and were embedded in soft tissue and bone. Successful surgical removal of the extruded gutta-percha with surrounding granulation tissue prompted proper healing and resolution of the long-term symptoms.
