Clinically Significant Bacteria

Front 1

Staphylococcus Aureus

Back 1

Gram +
Occurs in grape-like clusters.
Facultative anaerobes.
Salt lovers.
Normal flora most commonly found on the skin, GI tract and respiratory tract.
Beta hemolytic

Front 2

Streptococcus

Back 2

Gram +
Occurs in short to long chains.

Alpha: produces a green pigments around colonies; normal flora.

Beta: Produces complete hemolysis around organism (zone of clearing).
Group A (S. pyogenes): causes strep throat, pneumonia, ear infections and scarlet feaver.
Group B (S. agalactiae): Causes UTI. Group C (S. equisimilis): Causes sore throat.

Gamma: Produces no hemolysis.

Front 3

Enterococcus

Back 3

Gram +
Normal flora found in digestive and urogenital tracts.
Salt lovers.
Can cause UTI, abscesses and sepsis.

Front 4

Streptococcus pneumoniae

Back 4

Gram +
Virulent form of strep, produces a capsule which increases its virulence.
Major cause of pneumonia.
Alpha hemolytic organism.
Forms diplococci in chains.
Leading cause of meningitis.
Can be normal flora for a small population of people.

Front 5

Lactobacillus acidophilus

Back 5

Gram +
Normal flora found in the urogenital and GI tracts.
Assists in maintenance of an acidic pH via lactic acid production.
Usually in yogurt as an active culture, taken to repopulate normal flora of the gut.
Causes yeast infections.

Front 6

Corynebacterium diphtheriae

Back 6

Gram +
Leads to diphteria.
Bacteria must be infected via bacteriophage to produce the disease. A toxin is produced that leads to formation of a pseudomembrane.
Can damage nerves and heart.
Treated with anti-toxin to counteract the toxin; antibiotics also kill the organisms.

Front 7

Listeria monocytogenes

Back 7

Widely distributed in nature as it survives both high and low temperatures.
Found in cold dairy products and meat.
In pregnant women, can cross placenta and result in neonatal death.
After delivery, can cause meningitis and septicemia in babies.

Front 8

Bacillus anthracis

Back 8

Gram +
Facultative anaerobe; endospores are formed only under aerobic conditions.
Leads to anthrax.
Most anthrax occurs from contact with endospores in industries that handle wool, hides, meat or bones.
Spores can remain viable for over 60 years.

Front 9

Clostridium

Back 9

Gram +
Strict or obligate anaerobes.

C. perfringens: Spores introduced into tissues and necrosis or gas gangrene can occur. Bubbles and foul odor are prominent.

C. botulinum: Improper canning of foods accounts for 90% of food borne botulism. A powerful toxin is produced to block the release of acetylcholine.

C. tetani: Leads to tetanus, which causes muscles to stay in constant spasm (strong enough to break bones). A DPT vaccine has minimized the threat of tetanus.

C. difficile: Side effect of antibiotic overuse, it leads to antibiotic associated pseudomembranous colitis (mucoid, bloody diarrhea).

Front 10

Neisseria

Back 10

Gram -
Kidney bean shaped.
Thayer-Martin plate is required to grow Neisseria.

N. gonorrheae: Results in gonorrhea, 2nd highest STD in US. Can lead to multiple complications.

N. meningitis : Can be normal flora. Causes meningitis.

Front 11

Moraxella catarrhalis

Back 11

Gram -
Can cause respiratory illnesses, meningitis and ear infections.

Front 12

Haemophilus

Back 12

Gram -

H. influenzae: Number one cause of meningitis in children. Also causes ear infections, respiratory infections and acute epiglottitis. Vaccine available.

H. aegypticus: Major cause of conjunctivitis (pink eye).

H. ducreyi: Major cause of chancroids, ulcerataed areas on the genitals, and swollen inguinal lymph nodes.

Front 13

Gardnerella vaginalis

Back 13

Gram -
Normal flora in up to 40% of women.
When vaginal pH increases in alkalinity, G. vaginalis interacts with an anaerobe and results in bacterial vaginosis.
BV is an irritation of the vagina. Symptoms include itching, odorous discharge and pain.
Forms clue cells (squamous epi. cells covered in bacteria).

Front 14

Pseudomonas aeruginosa

Back 14

Gram -
Highly virulent.
Causes swimmers ear, UTI and wound infections.
Prime agent of death among immunosuppressed individuals such as burn, cancer and AIDS patients.
Cultures have grape-like odor.
Highly resistant to antibiotics.