Download Disease - Humble ISD

Disease and Bacteria
Small Pox
A white blood cell eating bacteria.
Slide # 2
What is an Infectious Disease?
1. Disease- a condition in which the body does not
function normally.
2. Infectious disease: disease caused by the
presence and activity of a microbial agent.
3. Epidemic- A local outbreak of a disease
concentrated in one area.
4. Pandemic-A widespread (over an entire country
or continent) outbreak of a disease
Slide # 3
Pathogens Are Infectious Agents
1. What causes infectious (contagious) disease?
a. Pathogen- any disease causing agent
b. Examples of Pathogen and Disease:
Virus -HIV causes AIDS
Bacteria -Streptococcus causes Strep
throat
Protist - Plasmodium causes Malaria
Fungi -fungi cause athlete’s foot &
ringworm
Slide # 4
How do you get an Infectious PATHOGEN?
1. Airborne: spread through coughing &
sneezing. Enter through the nose,
mouth, and move to lungs.
2. Contaminated food or water; enter
mouth & go to stomach & intestines.
3. Bites from vectors such as mosquitoes,
ticks, & fleas that transfer pathogens.
4. Enter through openings in the skin
(wounds & when you touch your eyes.)
5. Body fluids – which can be exchanged
through sexual activities, pregnancy, &
drug needles.
Slide # 5
How to Prevent the Spread of Diseases
1. Good Hygiene- washing hands & keeping
hands away from eyes, nose and mouth.
2. Proper cooking & water treatment.
3. Controlling Vectors- spraying for
mosquitoes, fleas, ticks, etc.
4. Abstinence from sexual activity.
5. Vaccinations- weak or dead strain of a
pathogen that is injected into a person so
the body can learn how to recognize and
fight off the pathogen.
Slide # 6
How are Diseases Treated?
1. Bacterial disease is treated with
antibiotics.
2. Viral infections do not have a cure.
Viral infections must “run their course”
until the body learns how to get rid of
it.
3. Over-the-counter medicines only treat
symptoms
Not All Bacteria Are “Bad Guys”
1. Live in human intestines (&
other organisms) and help in
digestion
2. Decomposers in Ecosystems
3. Work in the nitrogen cycle
(nitrogen fixation)
4. Used to clean up oil spills
(consume the oil)
5. Used to make food (yogurt,
cheese, etc)
Slide # 7
Bacteria and Disease
1. Bacteria cause disease in one of two ways:
a. Damage cells or tissues directly by breaking
them down for food (ex. Mycobacterium
tuberculosis)
Mycobacterium tuberculosis causes
tuberculosis. The bacteria feed on lung
tissue, causing damage to the lungs. Thus,
infected humans experience difficulty
breathing, and cough up blood and lung
tissue, until death results.
Slide # 8
Bacteria and Disease
2. Release toxins (poisons) that travel through the body
and interfere with the normal activity of the body. (ex.
Streptococcus, or strep throat, and Corynebacterium
diphtheriae, which causes diphtheria)
Corynebacterium
diphtheriae
Streptococcus
Binary Fission: Asexual Reproduction
Chromosome
(DNA)
Cell membrane
Cell wall
Chromosome duplicates & separates
Cell grows; chromosomes move
Divides into 2 cells
Growth and Reproduction: Conjugation
2nd step
1st step
3rd step
4th step
Result: No additional cells; cells genetically different
Slide # 9
Controlling Bacteria
1. Sterilization occurs by exposing bacteria to extreme
heat. Boil or cook food thoroughly.
2. Disinfectants are chemical solutions that kill
bacteria. Examples include bathroom cleaners,
soaps, detergents, Lysol, etc.
3. Overuse of disinfectants may increase the likelihood
that bacteria will become resistant to disinfectants
and become more dangerous and difficult to kill.
Slide # 10
Food Storage and Processing
1. Refrigeration: slows the growth of bacteria,
but does not kill them
2. Pasteurization
3. Boiling, frying, or steaming sterilizes many
kinds of food.
4. Using preservatives when canning food for
long periods is effective.
5. Using everyday chemicals such as salt,
vinegar, or sugar preserves foods.
Slide # 11
Preventing Disease
1. Antibiotics are compounds that block the growth
and reproduction of bacteria.
2. One side effect of antibiotics: may cause
diarrhea b/c antibiotics can kill beneficial
bacteria.
3. Overuse of antibiotics is creating antibiotic
resistance and bacteria are becoming difficult to
kill. Creates “super bugs.”
EOC Practice
What do vaccines do?
They cause the body to
produce antibodies to fight the
targeted disease.
Why is Sendai virus used as
a vaccine against HPIV-1?
A It alters the protein coat
of HPIV-1.
B It makes cells chemically
unrecognizable to HPIV-1.
C It forms a protective
barrier againstHPIV-1
D It triggers the production
of antibodies that fight
HPIV-1
Correct answer: D