Microbiology & Disease Study Guide

Basic Characteristics Microbe Definition Basic Characteristics How It Spreads Diseases It Can Cause Treatment of Disease Prevention Methods Bacteria Single-celled organisms that have no nucleus -Multiple shapes -Some are harmful and cause disease -Some are helpful and cure disease and break down decaying material -Contaminated foods -Contaminated soil -Contaminated water -Contact with other organisms, etc. -Strep throat -Staph infections -Food Poisoning -Tuberculosis -Bacterial pneumonia -Leprosy -Lyme disease, etc. Antibiotics -Proper hand washing & hygiene -Proper handling of food -Cover your mouth when you cough, etc.

Virus Non-living substance that has to inject its genetic material into a living host cell in order to reproduce -Can cause disease -Must infect host cell to reproduce & spread -Much smaller than bacteria A virus must infect the host cell to replicate – inject DNA into host cell Viruses can enter the body through ingestion, inhalation, and injection -AIDS -The common cold -The flu -Chickenpox -H1N1, etc. “let the virus run its course” Rest Treat symptoms Antiviral drugs for long term viruses like HIV, etc. -Hygiene -Proper hand washing -Vaccinations

-Decomposers – break down organic matter Fungi Any of a group of unicellular or multicellular spore-producing organisms “feeding” on organic matter -Living -Decomposers – break down organic matter Examples: yeast, molds, mushrooms, etc. -Some are harmful -Some are helpful Enters the body in multiple ways: -Ingestion -Inhalation -Contaminated soil -Contact with eyes, mouth, etc. -Ring worm -Yeast infections -Athlete’s foot -Eye, lung, skin, hair, and nail infections Antifungal medications and creams -Clean skin injuries -Wear a mask and/or gloves when working in damp, dusty areas -Proper hygiene

Parasite An organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's expense Most parasites want to keep the host cell alive Host cell: the cells of the host organism, much like a virus must infect the host cell to multiply -Enters the body through vectors -Enters the body through contaminated food, soil, and water -Giardia infections -Malaria, infections, etc. Prescription medications to kill parasite and to treat the infections -Proper hand washing and hygiene -Proper filtration of water -Proper handling of food -Preventative medications (before trips)

2. Which type of microbe causes each of the following diseases? Influenza: Ringworm: Strep Throat: AIDS: Athlete’s Foot: Rabies: Malaria: Food Poisoning: Virus Fungi Bacteria Parasite What vector carries it? Mosquito

3. Vocabulary Word Definition Prevention Methods of reducing the likelihood of contracting a disease Disease An abnormal functioning of the body or part of body, sometimes caused by infections Microbiology The study of organisms that are too small to see without a microscope Unicellular An organism made up of only one cell Antimicrobial A substance that kills microbes in an effort to prevent the spread of a disease Treatment The response to a disease provided by medical professionals Microbe A living organism that is so small it can only be seen with a microscope Antibiotic Drug that kills bacteria and cures only bacterial infections and diseases Host Cell The cells of the host organism, much like a virus must infect the host cell to multiply Pathogen Disease-causing organism

4. What is a vector? List at least three (3) examples of organisms that are common vectors. An organism (excluding humans) that spread diseases without showing symptoms – passes the disease onto the other organism Examples: mosquito, tick, flea, rat, other animals (i.e. rabies)

5. What do viruses and parasites have in common? How are they similar? Both viruses and parasites require a host cell in order to survive and reproduce Both viruses and parasites harm the cells that they enter

6. Explain the relationship between a virus and a host cell. Because a virus is nonliving and cannot reproduce on its own, it must inject its DNA into the host cell in order to replicate The virus “hijacks” the host cell to “grow” and reproduce

7. Use the image to describe the life cycle of a virus. Virus attaches to the host cell Virus injects DNA into host cell Virus attacks the cell & breaks it down Virus replicates (reproduces) Viruses are released and go on to infect other cells

8. Bacteria come in many shapes. Describe each of the following: Coccus: Bacillus: Spirillum: Spirochete: Spherical shaped Rod-shaped Spiral shaped Corkscrew shaped

9. What is the difference between an epidemic and a pandemic? An epidemic is an outbreak of a disease in a certain area, whereas a pandemic is a type of epidemic that is more widespread and infects a greater number of people There are two main differences between epidemic and pandemic. The term pandemic normally is used to indicate a far higher number of people affected than an epidemic. Pandemic also refers to a much larger region being affected. In the most extreme case, the entire global population would be affected by a pandemic.

10. Explain how a vaccine works to prevent viral infections. A vaccine contains a dead or weakened strain of a virus (that does not cause disease) When the vaccine is given to a person their cells go to work fighting the virus off (kind of like practice) to build up an immunity to the virus so when they are exposed to the actual virus the body already has a defense prepared to fight the virus

11. What is Rabies? How is it spread (what is the vector)? Rabies is caused by a virus – A disease that attacks the CNS (central nervous system) and causes acute encephalitis (swelling in the brain) which may cause an organism to act different or “mad;” it is usually fatal Rabies is spread through being exposed to the saliva of an infected organism (through a saliva in a bite or saliva if an open cut is licked) The infected organism is the vector