1. Gram Positive Bacteria
Digging Deeper into Bacterial Life
Part 1 of 3

2. Things to Remember All bacteria are procaryotes
Simplistic
Means “pre-nucleus”
The body fights them with leukocytes
Video of WBC chasing bacteria
Hospital workers fight them with antibiotics
Gram staining starts the identification process allowing people to see the following:
Color
Morphology
Clustering style
Video at:

3. Gram Positive Bacteria
Stain blue or violet*
Produce exotoxins
Have thick layer of peptidoglycan in cell membrane
More easily treated with antibiotic therapy than gram negative bacteria
Staphyloccus aureus is shown at the right
*Using gram staining technique. Note: due to different photography techniques, you may note colors other than expected.

4. Gram Positive Bacteria
Staphylococcus aureus
Streptococcus pneumoniae
Corynebacterium diphtheriae
Bacillus anthracis
Clostridium botulinum
Clostridium tetani

5. Staphylococcus aureus
Commonly referred to as Staph
Often found in nasal passages
Facultative
Opportunistic
Many strains resistant to antibiotics
Produce lactic acid
Note the name of the bacterium: staph means there is mass clustering while coccus refers to the spherical shape.
The photo shown was taken using electroscopy which is why the color is not blue.

6. Staphylococcus aureus
What does opportunistic mean?
Will not cause an infection in a host unless the immune system is already compromised
What compromises an immune system?
Illness
Stress
Use of corticosteroids (used by many respiratory patients)
Why is antibiotic resistance so important?
When bacteria stop responding to antibiotics, it increases the chances of serious illness and death from infection of that microbe
Corticosteroids information at:

7. Resistant S. aureus MRSA VRSA
Methicillin Resistant S. aureus
May be found in or on:
Respiratory tract and sputum
Skin
Gastrointestinal system
Wounds
VRSA
Vancomycin Resistant S. aureus
Found in same places as MRSA
It is especially important to avoid spreading these

8. Streptococcus pneumoniae
Commonly known as pneumococcus
Causes most of the severe cases of bacterial lobar pneumonia
Often found as diplococci but may be single or in chains
Produce hydrogen peroxide
Produces a pink salmon-colored sputum
This bacteria is quite finicky. The lab must provide very specific conditions to encourage growth. A very small amount of carbon dioxide is needed. Some S. pneumoniae require anaerobic conditions though in humans the bacteria flourish in the lungs which have plenty of oxygen. S. pneumoniae grows best in the presence of blood. They‘re considered fragile but find the lungs to be hospitable enough to set up shop and cause up to 80% of bacterial pneumonia cases. For more information, go to
Pneumonia information:

9. Streptococcus pneumoniae

10. S. Pneumoniae
CT scan of Pneumococcal pneumonia which is most dangerous when infecting the very young, the very old, or those with suppressed immune systems. Black indicates air-filled lung; white/grey indicates consolidation.

11. Corynebacterium diphtheriae
Found in nasal passages and skin
Aerobic bacillus
Cause of diphtheria
An upper respiratory tract infection
Symptoms include sore throat and fever
Can be fatal in up to 10% of cases
Successfully prevented with DPT vaccine
For more information go to Todar's website
Todar’s website:

12. Bacillus anthracis Aerobic bacillus
Forms spores which survive harsh environments
Causes anthrax
Three manifestations of human illness:
Dermal
Gastrointestinal
Respiratory
Mortality rate close to 100% though it is rare
Resembles common cold in early stages
Death occurs within 2 – 5 days
Treatable with antibiotics if started quickly after exposure

13. B. anthracis
CDC Website:
A vaccine is available for anthrax but has its own dangers. For more information, visit the CDC website

14. Clostridium botulinum
Anaerobic bacillus
Forms spores which survive harsh environments
Neurotoxins are ingested and cause botulism
Food poisoning
Contaminated canned food is the most common source
Destroyed by heating food to about 180°F for 10 minutes
Flaccid paralysis
May be life threatening
Look for signs such as drooping eyelids
Is the basis of botox injections
Flaccid paralysis definition:

15. C. botulinum
The neurotoxins that cause paralysis are used for Botox treatments
Botox injections are used to:
Decrease the appearance of wrinkles
Diminish chronic muscle tension
Prevent migraines caused by chronic muscle tension

16. Clostridium tetani Anaerobic bacillus Causes tetanus
Vaccine is available but needs to be repeated every 10 years
C. tetani can survive as a spore for up to 10 years
Neurotoxins enter wounds causing:
Rigid paralysis
Lockjaw
Respiratory arrest leading to death

17. C. tetani Child at right afflicted with tetanus.
Arms curled in fetal position due to rigid paralysis.
Lockjaw makes it impossible to open his mouth.
Common in 3rd world countries for survivors to have front teeth knocked out to provide a space to ingest food.
Rare for people in the U.S. to get tetanus due to availability of vaccine.

18. Next Steps
Please close this PowerPoint presentation and then click Assignment 3 to continue.