Epidemiological and clinical profile of infective endocarditis at a Brazilian tertiary care center: an eight-year prospective study

Abstract INTRODUCTION: Infective endocarditis (IE) is a systemic infectious disease requiring a multidisciplinary team for treatment. This study presents the epidemiological and clinical data of 73 cases of IE in Rio de Janeiro, Brazil. METHODS This observational prospective cohort study of endocarditis patients during an eight-year study period described 73 episodes of IE in 70 patients (three had IE twice). Community-associated (CAIE) and healthcare-acquired infective endocarditis (HAIE) were diagnosed according to the modified Duke criteria. The collected data included demographic, epidemiologic, and clinical characteristics, including results of blood cultures, echocardiographic findings, surgical interventions, and outcome. RESULTS: Analysis of data from the eight-year study period and 73 cases (70 patients) of IE showed a mean age of 46 years (SD=2.5 years; 1-84 years) and that 65.7% were male patients. The prevalence of CAIE and HAIE was 32.9% and 67.1%, respectively. Staphylococcus aureus (30.1%), Enterococcus spp. (19.1%), and Streptococcus spp. (15.0%) were the prevalent microorganisms. The relevant signals and symptoms were fever (97.2%; mean 38.6 + 0.05°C) and heart murmur (87.6%). Vegetations were observed in the mitral (41.1%) and aortic (27.4%) valves. The mortality rate of the cases was 47.9%. CONCLUSIONS: In multivariate analysis, chronic renal failure (relative risk [RR]= 1.60; 95% confidence interval [CI] 1.01-2.55), septic shock (RR= 2.19; 95% CI 1.499-3.22), and age over 60 years (RR= 2.28; 95% CI 1.44-3.59) were indirectly associated with in-hospital mortality. The best prognosis was related to the performance of cardiovascular surgery (hazard ratio [HR]= 0.51; 95% CI 0.26-0.99).

Aggregative adherent strains of Corynebacterium pseudodiphtheriticum enter and survive within HEp-2 epithelial cells

Corynebacterium pseudodiphtheriticum is a well-known human pathogen that mainly causes respiratory disease and is associated with high mortality in compromised hosts. Little is known about the virulence factors and pathogenesis of C. pseudodiphtheriticum. In this study, cultured human epithelial (HEp-2) cells were used to analyse the adherence pattern, internalisation and intracellular survival of the ATCC 10700 type strain and two additional clinical isolates. These microorganisms exhibited an aggregative adherence-like pattern to HEp-2 cells characterised by clumps of bacteria with a "stacked-brick" appearance. The differences in the ability of these microorganisms to invade and survive within HEp-2 cells and replicate in the extracellular environment up to 24 h post infection were evaluated. The fluorescent actin staining test demonstrated that actin polymerisation is involved in the internalisation of the C. pseudodiphtheriticum strains. The depolymerisation of microfilaments by cytochalasin E significantly reduced the internalisation of C. pseudodiphtheriticum by HEp-2 cells. Bacterial internalisation and cytoskeletal rearrangement seemed to be partially triggered by the activation of tyrosine kinase activity. Although C. pseudodiphtheriticum strains did not demonstrate an ability to replicate intracellularly, HEp-2 cells were unable to fully clear the pathogen within 24 h. These characteristics may explain how some C. pseudodiphtheriticum strains cause severe infection in human patients.

Isolamento e identificação de enterococcus sp em infecções endodônticas primárias / Isolation and identification of enterococcus sp in primary endodontic infections

Este estudo objetivou o isolamento e caracterização bioquímica de Enterococcus sp de canais radiculares portadores de necrose pulpar de 70 pacientes. Foram isoladas 35 amostras de Enterococcus sp em 50% dos pacientes (n = 35) com a seguinte prevalência: 33 amostras Enterococcus faecalis (94,28%), 1 amostra Enterococcus faecium (2,85%) e 1 amostra Enterococcus durans (2,85%). Dos dentes com cultura positiva, 20 apresentaram sintomatologia dolorosa. Odor fétido e secreção purulenta foram observados em três dentes (8,57%). Dos 35 pacientes com cultura positiva, quatro apresentaram edema no momento da coleta e apenas um paciente apresentou fístula. A espécie E. faecalis foi majoritária, estando relacionada aos sinais e sintomas.

Efeito de componentes de dentifrícios infantis sobre Streptococcus mutans cultivados em biofilmes / Children's dentifrices components effect in Streptococcus mutans grown in biofilms

O estudo objetivou avaliar a capacidade de formação de biofilme de novo por S. mutans após tratamento de biofiolmes pré-formados com composições de dentifrícios: I- base contendo 500 ppm NaF2 e 2,5% xilitol; II-base contendo 500 ppm Naf2; III-base contendo 10% xilitol; IV-base sem aditivos; V- solução salina fisiológica. Todas as formulações inibiram a formação de novo do biofilme por S. mutans. Maiores inibições foram encontradas para os tratamentos I e II. A composição III também foi efetiva na inibição. As formulações contendo xilitol e/ou NaF2 modularam a formação do biofilme por S. mutans in vitro.

Papel dos Enterococcus SP nos processos infecciosos de natureza endodôntica / Role of Enterococcus SP on infections process of Endodontic origin

Os Enterococcus Faecalis são os microorganismos anaeróbicos facultativos mais comumente isolados nas infecções refratárias à terapia endodôntica. Incluem-se entre os fatores de virulência produzidos por essa espécie a habilidade em formar biofilmes, a capacidade de invandir túbulos dentinários além da atividade proteolítica e o desenvolvimento de resistência aos agentes antimicrobianos. O controle das infecções endodônticas causadas por E. faecalis requer preparo químico-cirúrgico adequado, com utilização de irrigantes em abundância, medicação intracanal e obturação efetiva com materiais dotados de atividade antimicrobiana. Evidências indicam a necessidade de novos estudos acerca do papel das infecções endodônticas na disseminação sistêmica dos E. Faecalis.