Properties of Life

OpenStax Biology 2e All living organisms share several key characteristics or functions: order, sensitivity or response to the environment, reproduction, adaptation, growth and development, regulation, homeostasis, energy processing, and evolution. When viewed together, these nine characteristics serve to define life. A toad represents a highly organized structure consisting of cells, tissues, organs, and organ systems. … Continue reading Properties of Life

Hansen’s Disease (Leprosy)

(a) The nose of a patient with Hansen’s disease. Note the lepromatous/multibacillary lesions around the nostril. (b) Hansen’s disease is caused by Mycobacterium leprae, a gram-positive bacillus. (credit a, b: modifications of work by the Centers for Disease Control and Prevention) OpenStax Microbiology Hansen’s disease (also known as leprosy) is caused by a long, thin, filamentous rod-shaped bacterium Mycobacterium … Continue reading Hansen’s Disease (Leprosy)

Anaplasmosis

By Alan R Walker - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=17509613 OpenStax Microbiology The zoonotic tickborne disease human granulocytic anaplasmosis (HGA) is caused by the obligate intracellular pathogen Anaplasma phagocytophilum. HGA is endemic primarily in the central and northeastern US and in countries in Europe and Asia. HGA is usually a mild febrile disease that causes flu-like symptoms … Continue reading Anaplasmosis

Granulomatous Amoebic Encephalitis

(a) Brain tissue from a patient who died of granulomatous amebic encephalitis (GAE) caused by Balamuthia mandrillaris. (b) A close-up of the necrosis in the center of the brain section. (credit a, b: modifications of work by the Centers for Disease Control and Prevention) OpenStax Microbiology Acanthamoeba and Balamuthia species are free-living amoebae found in many bodies of fresh … Continue reading Granulomatous Amoebic Encephalitis