The aim of this passage is to discuss various types of microorganisms that cause disease. Microorganisms are simple organisms that are unicellular or live in colonies. The group contains bacteria, virus, algae, fungi, protozoa. They can be divided into pathogenic and non-pathogenic. In this passage pathogenic microorganisms that cause diseases are concerned. A disease is an abnormal condition affecting the body of an organism. Some of them called infectious diseases such as common cold, influenza, etc.
SARS coronavirus is an air-borne virus causes a respiratory disease in humans called Severe Acute Respiratory Syndrome (SARS). It transmits by riding on dust particles or small respiratory droplets and staying suspended in air and travel distances on air currents. SARS coronavirus is large, pleomorphic and spherical shape and consist of a single stranded of RNA. On the surface, it has bulbous surface projections. Its lipid envelop appears to consist of a distinct pair of electron dense shells. In order to infect a host, its replication takes place in the cytoplasm in a membrane-protected microenvironment. It incorporates the viral genetic materials into the host’s cells. Translation of the genome then takes place to produce the viral replicase. Viral replicase catalyzes that replication to produce new viral particles which move on to infect other cells. Different coronaviruses cause different transcription and translation patterns in the host.
The symptoms of SARS include fever of 38 °C, Myalgia, lethargy, gastrointestinal symptoms, cough, sore throat, etc.
Vibrio cholerae is a water borne bacteria causes Cholera and transmits by being carried in water or contaminated food such as shellfish and plankton to get into human bodies.