Orientia Tsutsugamushi

Bacterium Orientia Tsutsugamushi Budding From Its Host Cell Peritoneal Mesothelial Cell, Colorized Tem. This Specimen Comes From The Peritoneal Cavity Of A Mouse Infected Experimentally To Diagnose The Infection Of A Patient. Other Bacteria Are Visible In The Cytoplasm. Orientia Tsutsugamushi, Formerly Known As Rickettsia Tsutsugamushi, Is A Bacterium Responsible For Scrub Typhus Or Japanese Flood Ever. It Is A Gram Negative Bacillus, Intracellular Exclusively, That Proliferates Into The Cytoplasm Of The Macrophages, Dthe Endothelial Cells And The Polynuclear Neutrophils ; Therefore It Provokes Its Own Phagocytosis Through Those Cells, Then Live Freely In The Cytoplasm, Then Exit The Host Cell By Budding. Scrub Typhus Is A Disease Characterized By A High Fever 40°C, Cephalgias, Coughs, Obnubilations And An Adenopathy. This Zoonose Is Endemic In Eastern Asia And Western Pacific. It Is Transmitted Through Wild Rodents, That Are Its Reservoir, To Mankind By A Sting Of Trombiculidae Larvae From The Genus Leptotrombidium. Orientia Tsutsugamushi > Orientia > Rickettsie > Rickettsiaceae > Rickettsiales > Proteobacteria > Bacterium. This 1978 Transmission Electron Micrograph Tem Depicted A Brain Capillary Of A Mouse That Had Been Experimentally Infected Intravenously With Orientia Tsutsugamushi Rickettsial Micro Organisms. This Tem Revealed That One Organism Was Budding From The Luminal Surface Of A Hypertrophic Capillary Endothelial Cell, Still Covered By A Third Layer Consisting Of The Host Cell's Plasma Membrane. Others Are Visible Free Within The Endothelial Cell's Cytoplasm. In Humans, O. Tsutsugamushi Attacks Endothelial Cells Resulting In Vasculitis. The Clinical Manifestations Are Characterized By Papular Rash, Headache, Fever, Chills, And An Eschar At The Site Of The Chigger Bite, I. E. The Mode Of Human Inoculation. The Disease Can Be Tested Serologically By The Det (Photo By BSIP/UIG Via Getty Images)