Pathogens

Question 1

What are the five major classes of pathogens?

Answer 1

1. Bacteria
2. Viruses
3. Fungi
4. Protozoa
5. Multi-cellular Parasites

Question 2

Define Endotoxins

Answer 2

Structural component of bacteria released when bacteria are lysed.

Question 3

Define Exotoxins

Answer 3

Toxin excreted by a microorganism.

Question 4

List 5 examples of Protozoa.

Answer 4

Coccidiosis, Cryptosporidium, Toxoplasmosis, Trichomoniasis, Neospora

Question 5

List 6 examples of Multi-Cellular Parasites.

Answer 5

Large Roundworms, Trichinosis, Tapeworm, Lice, Ticks, Mange

Question 6

How to Fungi reproduce?

Answer 6

Asexually- spores or mycelia fragmentation

Sexually- meiosis

Question 7

List all 4 of Koch’s Postulates.

Answer 7

1. The microorganism must be found in all organisms suffering from the disease, but should not be found in healthy animals.
2. The microorganism must be isolated from a diseased organism and grown in pure culture.
3. The cultured microorganism should cause disease when introduced into a healthy organism.
4. The microorganism must be re-isolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.

Question 8

Describe the germ theory of Edward Jenner.

Answer 8

Took cowpox blister, scratched it into the skin of a young boy, then inoculated him with smallpox. No disease.

Question 9

Described the germ theory of Delafond.

Answer 9

Blood from dead sheep contained anthrax microorganisms that would reproduce.

Question 10

Describe the germ theory of Koch.

Answer 10

Animals injected with anthrax germs became ill, discovered bacteria that caused TB, cholera, anthrax.

Question 11

Describe the germ theory of Pasteur.

Answer 11

Developed first effective vaccine (to anthrax). Took the invention of the microscope.

Question 12

Describe the 3 shapes of bacteria.

Answer 12

Cocci- circular
Bacillus- rod
Spirillum- spiral

Question 13

List the 6 arrangements of cocci.

Answer 13

Coccus, diplococci, staphylococci, streptococci, sarcina, tetrad.

Question 14

Describe Bacteria.

Answer 14

Unicellular organisms which have cell walls but lack organelles and an organized nucleus, including some that can cause disease.

Question 15

Describe Viruses.

Answer 15

Viruses contain a protein coat surrounding an RNA or DNA core of genetic material. They are capable of growth and multiplication ONLY in living cells. They are easily transmitted due to size and often very contagious. Viruses also cannot live or reproduce independently.

Question 16

Describe Fungi.

Answer 16

Fungi includes yeast, molds, and mushrooms. The reproduce both asexually and sexually. The cell walls contain chitin (long hard polymer that makes up the exoskeletons of crustaceans). Fungi are often difficult to eliminate due to sores and fragmentation. Some produce a poisonous substance called mycotoxin.

Question 17

List one example of Fungi.

Answer 17

Ringworm

Question 18

List 4 toxins of Fungi.

Answer 18

Aflatoxins, Vomitoxine, Ergot alkaloids, fusarium-zearalenone

Question 19

Describe Protozoa.

Answer 19

Unicellular eukaryotes either free-living or parasitic, which feed on organic matter such as other microorganisms or organic tissues and debris. They produce oocysts (protozoan spore), a highly resistant stage which may survive for a long time in the fecal material if the host or in the soil.

Question 20

Describe Multi-Cellular Parasites.

Answer 20

Any of the large multicellular parasites. They typically have a complicated lifecycle with multiple phases and can be difficult to control due to life stages and drug resistance.