Ch.15 Microbiology

Question 1

Pathogenicity

Answer 1

ability to cause disease by over coming host defenses

Question 2

Virulence

Answer 2

extent of pathogenicity (how serious it is)

Question 3

Portal of entry

Answer 3

Mucous membranes, Skin, parenteral route (cuts bites wounds). Preferred portal of entry is what a microbe prefers

Question 4

IDv50

Answer 4

Infectious dose for 50% of the test population, shows virulence

Question 5

LDv50

Answer 5

lethal dose, of a toxin

Question 6

Parenteral route

Answer 6

portal of entry but only through injury or penetration

Question 7

how is adherence and adhesion achieved

Answer 7

adhesins/ligands bind to surface receptors of their host cells.

Question 8

Where are a pathogens ligands/adhesins located?

Answer 8

some on the glycocalyx, fimbriae, flagella. , opa and M protein (has 100 types)

Question 9

Biofilms

Answer 9

masses of microbes that share resources and come together. They are resistant to disinfectants and antibiotics

Question 10

How do capsules protect pathogens

Answer 10

they prevent phagocytosis, by stopping the phagocytes from adhering

Question 11

What cell wall components protect pathogens

Answer 11

M proteins- resist phagocytosis
Opa protein- inhibits T helper cells
Mycolic acid (waxy lipid)- resists digestion

Question 12

Coagulase

Answer 12

bacterial enzyme’s that coagulate fibrinogen (blood clots)

Question 13

Kinases

Answer 13

digest fibrin clots that the body makes to isolate bacterial infection

Question 14

Hyaluronidase

Answer 14

hydrolyzes hyaluronic acid, a polysaccharide that holds together certain cells of the body

Question 15

Collagenase

Answer 15

hydrolyzes collagen which is found in connective tissue like muscle and organs

Question 16

Iga proteases

Answer 16

kill antibodies

Question 17

Antigenic Variation

Answer 17

the changing of pathogen antigens, so that antibodies do not kill them

Question 18

Siderophores

Answer 18

proteins take away nutrients from its hosts, like iron away from hemoglobin.

Question 19

Invasins

Answer 19

proteins secreted by pathogens in order to manipulate the cytoskeleton of host cells via its actin. They use actin and cadherin to propel themselves from cells to cell

Question 20

How do pathogens damage cells

Answer 20

Disrupt cell functions, produce waste products and toxins

Question 21

Toxin

Answer 21

substance that contributes to pathogenicity

Question 22

Toxigenicity

Answer 22

ability to produce a toxin

Question 23

toxemia

Answer 23

presence of toxin in host blood

Question 24

Toxoid

Answer 24

inactivated toxin used for a vaccine

Question 25

Antitoxin

Answer 25

Antibodies against a specific toxin

Question 26

Exotoxins

Answer 26

produced inside pathogenic bacteria, and secreted outside the cell . Manly gram positive

Question 27

Endotoxins

Answer 27

Mainly gram negative, are kipid portions of the outer membrane, secreted when the bacteria die and fall apart.

Question 28

Exotoxins categories

Answer 28

A-B toxins, Membrane disrupting toxins, Super antigens

Question 29

How do a-b exo toxins toxins work

Answer 29

AB is made by bacteria , the B (binding portion) goes into the host cell receptor and then the plasma receptor , enters receptor mediated endocytosis. they enter and the A part disrupts the cell while the B cell leaves and the cell receptor back to be reused.

Question 30

What do membrane - disrupting toxins do

Answer 30

make protein channels in the plasma membrane , some disrupt the phospholipid bilayer

Question 31

What do super antigen exotoxins do

Answer 31

cause an intense immune response due to release of cytokines from host cells those stimulate T cells. Examples are food poisoning and toxic shock syndrome

Question 32

Exotoxin overview

Answer 32

mostly gram positive, by products of growing cell. Protein, generally no fever, neutralized by antitoxin and LD50 is small

Question 33

Endotoxins overview

Answer 33

mostly gram negative, in the outer membrane, Lipid, causes fever , not neutralized by antitoxin the LD50 is relatively large

Question 34

How do endotoxins cause fever

Answer 34

a macrophage ingests a gram negative bacteria, the endotoxins are released that cause the macrophage to produce cytokines. the cytokines go to the hypothalamus that produce prostaglandins.

Question 35

LAL Assay

Answer 35

Used to detect endotoxin. use amoebocytes from a literal horshoe crab . They have protein that cause clotting if there are endotoxins present . lysis occurs

Question 36

Cytopathic effects of viruses part 1

Answer 36

stops macromolecular synthesis in host cells, host cell lysosomes release enzymes and kill themselves, form syncytium that are multineclie cells made of multiple infected cells

Question 37

Cytopathic effects of viruses part 2

Answer 37

Cytocidal (cell death) , inclusion bodies, parts of viruses in the middle of becoming virusus, transformation, and destruction of T cells.

Question 38

Pathogenic effects of fungi

Answer 38

fungal waste products can cause symptoms, allergic response , toxins can inhibit protein synthesis, proteases modify cell membranes, capsules can prevent phagocytosis

Question 39

Pathogenic effects of fungi

Answer 39

ergot toxin (LSD), constrict blood flow, Aflatoxin, carcinogenic substance, Mycotoxins neurotoxins.

Question 40

Pathogenic effects of protozoa

Answer 40

presence can cause diarrhea, protozoan waste products can cause symtpoms, grow in phagocytes, antigenic variation

Question 41

Pathogenic effects of protozoa

Answer 41

use host tissue and interfere with functions. the waste can cause symptoms

Question 42

Pathogenic properties of Algae

Answer 42

neurotoxins from diatoms, and dinoflagellates, Demonic acid and asxitoxin

Question 43

Portal of exit

Answer 43

respiratory tract , caogh and sneese gastroinsteinal tract poop and saliva , genitourinary tract urine, and vaginal secretions. , skin, blood