Microbiology (Made Easy) Chapter Two

Front 1

Flagella

Back 1

Protein filaments that extend like long tails from the cell membranes of certain gram-positive and gram negative bacteria. It is used to move the cell around.

The tails are often several times the length of the bacterial cell

Front 2

Basal Body

Back 2

Affixes the flagellum to the bacteria, it spans through the entire cell wall and binds to the inner and outer cell membrane

The basal body spins around causing the flagella to swing and this movement is called chemotaxis

Front 3

What's an example of a bacteria with one polar flagella?
What's an example with with flagella all around the cell?
What's an example with no flagella?

Back 3

Vibrio cholera have one polar flagella

Escherichia Coli has flagellas all around the cell

Shigella does not have a flagella

Front 4

Pili

Back 4

straight filaments arising from the bacterial cell wall, making the bacterium look like a porcupine, their purpose to adherence factors and are vital to their ability to cause disease

Front 5

Capsules

Back 5

protective walls that surround the cell membranes of bacteria

composed of simple sugar residues (rarely amino acids: Anthracis)

enable bacteria to be more virulent because phagocytes and neutrophils are unable to encapsulate them

Front 6

What are two tests that enable doctors to visualize capsules under the microscope?

Back 6

India ink stain, everything stains besides the capsule which looks like a halo around the cell

Quellung Reaction: Bacteria are mixed with antibodies that bind to the capsule

Front 7

Opsonization

Back 7

the process of antibodies binding to the capsule

used in strep. pneumonia vaccine

Front 8

Endospores

Back 8

metabolically dormant forms of bacteria that are resistant to heat (boiling) and have multiple layered coats outer layer called: exosporium

2 Genera produce spores: Bacillus and anaerobic Clostridium

Front 9

Biofilms

Back 9

extracellular polysaccharide network similar to a capsule polysaccharides that forms a mechanical scaffold around the bacteria

it allows them to bind to prosthetic devices like catheters and protects them from antibiotic attacks

Front 10

Facultative Intracellular Organisms

Back 10

Bacter that are phagocytosed by the host macrophage and neutrophils and survive within them

they escape the lysosome and peroxide toxins and are safe from antibodies within the cells

Front 11

List the Facultative Intracellular Organisms

Back 11

Listeria monocytogenes, Salmonella typhi, Yersinia, Francisella tularensis, Brucella, Legionella, Mycobacterium

Mnemonic: Listen Sally Yer Friend Bruce Must Leave

Front 12

Exotoxins

Back 12

proteins released by bacteria that cause disease

released mostly by gram positive bacteria, some gram negative release it

exotoxins include anthrax, botulism, tetanus, and cholera

Front 13

Neurotoxins

Back 13

Exotoxins that act on the nerves or motor endplates to cause paralysis. Tetanus toxin and botulinum toxin are examples.

Front 14

Enterotoxins

Back 14

exotoxins that act on the grastrointestinal tract to cause diarrhea. They inhibit resorption of NaCl, activate NaCl excretion, or kill epithelial cells. It results in osmotic pull of fluid into the intestine causing diarrhea. Either Infectious diarhea or Food Poisoning.

Front 15

Infectious Diarrhea

Back 15

Bacteria that colonizes and binds to GI tract continuously releasing their enterotoxins. They continue to grow unless stopped by immune system or antibiotics.

Examples: Vibrio cholera, E. Coli, Campylobacter jejuni, Shigella dysenteriae

Front 16

Food Poisoning

Back 16

Bacteria that grows in the food and release enterotoxin in the food, its ingested and results in diarrhea vomiting for less than 24 hours

Front 17

Pyrogenic exotoxins

Back 17

stimulate the release of cytokines and can cause rash, fever, and toxic shock syndrome, examples staph. aureus and pyogenes

Front 18

Tissue Invase Exotoxins

Back 18

allow bacteria to destroy and tunnel through tissue. includes enzymes that destroy DNA, collagen, fibrin, NAD, RBCs and WBCs

Front 19

Exotoxin Subunits

Back 19

in major exotoxin bacteria composed of two polypeptide subunits bound by disulfide bridges. one called B for binding and the other A for action

Front 20

Endotoxin

Back 20

remember it is Lipid A in the outer membrane of LPS of gram negative bacteria. its released when the cell lyses

Front 21

Septic Shock

Back 21

a common and deadly response to bacterial infection, also referred to endotoxic shock because it is often triggered by endotoxins, causing dangerous drop of blood pressure and organ dysfunction

Body releases Tumor Necrosis Factor (TNF) which causes hypotension and shock

Front 22

Bacteremia

Back 22

bacteria in the blood stream, can be seen by blood culture

Front 23

Sepsis

Back 23

Bacteria that causes a systemic immune response to the infection, high fever, fast heart rate, heightened WBC count

Front 24

Treatment of Septic Shock

Back 24

1) Find site of infection (commonly the lungs, followed by abdomen and urinary tract)
2) Quick antibiotic therapy
3) Support Blood Pressure

Front 25

4 Bacteria that produce exotoxins that increase cAMP levels

Back 25

cholera
Anthrax
Motezuma's revenge (enterotoxic E. Coli)
Pertussis (Bordetella pertussis)