Microorganisms and Their Groups

Microorganisms

• Microorganisms are tiny living organisms too small to see with the naked eye
• They include bacteria, viruses, fungi, and protists
• Found everywhere in the environment (soil, water, air, bodies)
• Some cause diseases, others play roles in: decomposition, nutrient cycling, food production
• Essential to life on Earth, used in biotechnology, medicine, and industry

Microbial Groups

• Viruses, Bacteria, Fungi, Protozoa, Algae, Archaea (and others like rickettsial)

Fields Dealing with Microorganisms

• Virology: Study of viruses (structure, function, classification, interactions with host organisms)

• Bacteriology: Study of bacteria (morphology, physiology, genetics, ecology, pathogenesis)

• Mycology: Study of fungi (structure, function, ecology, genetics, evolution) - Mycologists study mushrooms, molds, yeasts, and other microscopic fungi.

• Protozoology: Study of single-celled eukaryotic organisms (protists, not plants, animals, or fungi) Includes amoebas, ciliates, flagellates, and sporozoans.

• Phycology: Study of algae (photosynthetic organisms, from microscopic to large seaweeds)

• Archeology: Study of archaea (single-celled microorganisms distinct from bacteria and eukaryotes) Found in extreme environments (hot springs, saline lakes, deep sea vents)

Viruses

• Tiny infectious agents that can only replicate inside living cells (animals, plants, bacteria)

• Not considered living (cannot reproduce or carry out metabolic processes independently)

• Consist of genetic material (DNA or RNA) surrounded by a protein coat (capsid) - some have lipid envelope

• Infect a wide range of organisms

• Bacteria (bacteriophages)

• Plants (phytoviruses)

• Animals (veterinary viruses)

• Fungi (mycoviruses)

• Protozoa

• Humans

• Cause diseases like influenza, HIV/AIDS, Ebola, and COVID-19 in humans, and in animals and plants

Viruses Affecting Man (Specific Examples)

• Cutaneous/Dermatotropic Viruses:

• Human papillomavirus (HPV): Warts, skin/genital cancers

• Molluscum contagiosum virus: Skin lesions

• Herpes simplex virus (HSV): Cold sores, genital herpes

• Varicella-zoster virus (VZV): Chickenpox, shingles

• Human T-cell lymphotropic virus (HTLV): Adult T-cell leukemia/lymphoma, skin lesions

• Other viruses: Monkeypox, rubella, polio, rabies etc

• Neurotrophic Viruses (affect the nervous system):

• Herpes simplex virus (HSV): Encephalitis

• Varicella-zoster virus (VZV): Shingles

• Epstein-Barr virus (EBV): Neurological complications (encephalitis, meningitis, Guillain-Barré)

• West Nile virus (WNV): Encephalitis

• Rabies Virus: fatal

• Blood-borne Viruses (hematological viruses):

• Human immunodeficiency virus (HIV): AIDS

• Hepatitis B virus (HBV) and Hepatitis C virus (HCV): Liver disease, liver cancer, liver failure

• Cytomegalovirus (CMV): Anemia, blood disorders

• Gastrointestinal Viruses (affect GI tract):

• Norovirus: Acute gastroenteritis

• Rotavirus: Diarrhea, especially in children

• Adenovirus: Diarrhea, vomiting, fever

• Astrovirus

• Respiratory Viruses:

• Rhinoviruses: Common cold

• Influenza viruses: Flu

• Respiratory syncytial virus (RSV): Respiratory infections

• Coronaviruses: Wide range of respiratory illnesses (SARS-CoV-2, COVID-19)

• Eye Viruses:

• Herpes simplex virus (HSV): Herpes keratitis (corneal blindness)

• Other Viruses: Varicella-zoster virus (VZV), Cytomegalovirus (CMV), Yellow fever, dengue, kassala fever, Ebola etc

Explore the fascinating world of microorganisms including bacteria, viruses, fungi, and protists. This quiz covers their roles in the environment, their importance in various fields such as virology and bacteriology, and their applications in biotechnology and medicine. Test your knowledge on these essential life forms and their classifications.