Introduction to Bacteria and Viruses

Tara C. Dale

September 7, 2007

Kyrene Akimel A-al Middle School

Bacteria and Viruses Microbes are things that are so small we can not see

them with our naked eye. Germs are things that make us sick. Bacteria can be good, bad, or indifferent to the human

body. Therefore:

All bacteria and viruses are microbes but not all microbes are bacteria and viruses.

All germs are bacteria or viruses but not all bacteria are germs. All viruses are germs.

Viruses are not considered organisms because they are not considered alive.

Bacteria are unicellular microbes that do not have a nucleus.

Healthy Bacteria

human body contains many bacteria, most performing useful, and sometimes even essential, tasks

estimated at 500 – 1,000 different types of bacteria live in the human body

example of good bacteria include those living in our digestive tract that break down certain carbohydrates that our body can’t break down itself; E.coli

Unhealthy Bacteria and Viruses

Some bacteria are not healthy for the human body and can cause illness and/or death.

Some viruses kill bacteria so they can be considered good but they usually kill healthy cells too so ultimately they are considered unhealthy

All viruses kill the cells they penetrate; all viruses are unhealthy

Cercopithecine herpesvirus 1 also known as B Virus an infectious agent that is commonly found among

macaque monkeys does not harm monkeys but harms humans – infection is

rare but once you are infected you are likely to die occurs mostly in lab scientists and veterinarians infection usually occurs because of an animal bite, exposure to monkey’s bodily fluids, or a scratch no known treatment; CDC has a team researching one

Bordetella pertussis (Pertussis)

Bacterial infection that can be fatal Transmitted from mucus of one infected person

to another person; patients with Pertussis cough A LOT!

Symptoms include hypoxia, apnea, pneumonia, seizures, encephalopathy, and malnutrition

A vaccine does exist; most who get Pertussis are too young to be vaccinated

Pertussis Pictures

Clostridium botulinum (Botulism) Bacterial infection transmitted through infected

food, in a wound that has the bacteria, or by consuming bacterial spores that create the toxin

Symptoms include double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, and muscle weakness

Treatment includes giving patients antitoxin; most need to be on breathing machines for several weeks during the treatment

Botulism Picture

Rabies

A virus transmitted from one infected patient to another organism, usually from an animal bite

Symptoms include a change in behavior, loss of appetite, desire to be alone, fever, seizures

Once symptoms begin in humans, there is no treatment; a vaccination exists for those who are more likely to come in contact with rabid animals such as veterinarians

Vaccinations and treatment shots take place several times over a 28-day period; done in the arm and is now quite painless (historically it was VERY painful)

Rabies Picture

This man had to be restrained to keep from hurting himself and others.

Streptococcus (Scarlet Fever)

Bacteria that cause strep throat but also a toxin that causes a distinctive rash called Scarlet Fever

Transmission occurs from person to person Symptoms include fever, chills, body aches,

nausea, vomiting, and loss of appetite may occur.

Treatment involves antibiotics

Scarlet Fever Pictures