Epigenetic Silencing of Host Cell Defense Genes Enhances Intracellular Survival of the Rickettsial Pathogen Anaplasma phagocytophilum

Intracellular bacteria have evolved mechanisms that promote survival within hostile host environments, often resulting in functional dysregulation and disease. Using the Anaplasma phagocytophilum–infected granulocyte model, we establish a link between host chromatin modifications, defense gene transcription and intracellular bacterial infection. Infection of THP-1 cells with A. phagocytophilum led to silencing of host defense gene expression. Histone deacetylase 1 (HDAC1) expression, activity and binding to the defense gene promoters significantly increased during infection, which resulted in decreased histone H3 acetylation in infected cells. HDAC1 overexpression enhanced infection, whereas pharmacologic and siRNA HDAC1 inhibition significantly decreased bacterial load. HDAC2 does not seem to be involved, since HDAC2 silencing by siRNA had no effect on A. phagocytophilum intracellular propagation. These data indicate that HDAC up-regulation and epigenetic silencing of host cell defense genes is required for A. phagocytophilum infection. Bacterial epigenetic regulation of host cell gene transcription could be a general mechanism that enhances intracellular pathogen survival while altering cell function and promoting disease

The prevalence of brucellosis in adults in Northeastern region of Turkey

Background: Brucellosis is prevalent in the Mediterranean basin, the Indian subcontinent, the Arabian peninsula, and in parts of Central Asia, Africa, Central and South America. However it continues to be one of the major health problems in developing countries, including Turkey. Objectives: The current study aimed to determine the incidence of brucellosis, which is previewed to be very common in the northeastern region of Turkey, in order to emphasize the problem. Materials and Methods: Seroprevalence of brucellosis was examined in sera of 2913 patients who referred to Igdi{dotless}r State Hospital between February and December of the year 2010 by Standard Tube Agglutination Test method. Results: Results were statistically evaluated using chi-square trend analysis method. Significantly high level (1/40 dilution) of specific antibodies were detected in 525 (18 %) patient sera (P = 0.111). Conclusions: We hope that Turkey will be one of the brucellosis-free countries in near future with highlights from the current and further studies. © 2013, Ahvaz Jundishapur University of Medical Sciences