BASIC MICROBIOLOGY

Definition Microbiology is the science that studies living organisms that cannot be seen with the naked eye (microorganisms or microbes)

Nature of Microorganisms Most microorganisms are harmless, some are beneficial and others harmful (pathogenic) causing disease eg. E. coli from the colon (breaks down waste/makes vitamin K) can enter the urinary tract and cause an infection

Types of Microorganisms Major types are: Bacteria Fungi Protozoa (protists, parasites) Viruses

Transmission or Spread of Microorganisms Vectors – usually an animal or insect that carries the microorganism Airborne - spread through the air by people's coughing and sneezing Direct contact - an infected person touching a surface and then another person touching that surface Fecal-oral - contaminated hands, food and water Sexually Transmitted – direct transfer of bodily fluids (blood, semen)

Transmission or Spread of Microorganisms

Bacteria most familiar of the microbes that infect humans classified by their shape and arrangement Type Shape Arrangement Diplococci Round in pairs Staphylococci in groups or clusters Streptococci in chains Bacilli Rod-shaped in pairs, single, or in chains Spirilli Cork-screw or spiral single

Bacterial Resistance What is the proper way to take your antibiotics? Why are you not prescribed antiobiotics every time that you have some type of flu or cold symptoms? What is MRSA? What are nosocomial infections?

Fungi Once classified as plants but they don’t undergo photosynthesis Saprophytes – feed on dead or decaying material Thrive in moist environments Examples (mould, mildew, yeast) Cause some diseases in humans Ringworm Athlete’s foot Thrush Poisonous

Ringworm Skin infection causing severe itching (scalp, groin, beard) If left untreated can be passed on to others by direct or indirect contact, infected wrestling mats Treated with fungicides, antifungal creams

Athlete’s Foot Related to dirty showers and running shoes Moist area between toes

Thrush – yeast infection

Protists (Protozoa) Also known as parasites Mostly unicellular Eukaryotes Thrive in moist environments Cause disease in humans Malaria Food poisoning Leishmaniasis Trypanosomiasis

Disease from Protists Malaria Food poisoning Leishmaniasis https://www.youtube.com/watch?v=IVbq2yQH52g Food poisoning https://www.youtube.com/watch?v=jlvXtvWm80A Leishmaniasis https://www.youtube.com/watch?v=JR44Y0wUaX0 Trypanosomiasis https://www.youtube.com/watch?v=4aVUrGO97Zg

Viruses A virus is a microorganism that reproduces inside the cells of living hosts viruses attach to and enter the host cell and force the cell into making more viruses Viruses can cause diseases in humans (HIV, common cold, Zika, Ebola) Death of the host cell leads to symptoms Some viruses remain dormant in the body for long periods without symptoms (herpes, chicken pox virus) Viruses are usually completely eliminated by a healthy immune system, Antibiotics have no effect on viruses, Vaccines that produce lifelong immunity can prevent some viral infections.