Stages Microbe Do To Bring Disease

Question 0

What are the phagocytysis order of events?

Answer 0

1 chemo taxis

2 adhesion of bacterial cells

3 engulfment

4 phagosome

5 phagolysosome formation

6 kill/destruct bacterial cells

7 release of residual debris

Question 1

What is a pathogen?

Answer 1

any microbe causing disease

Question 2

What is superinfection and how does it occur?

Answer 2

superinfection is a new infection caused when a small number of microbes begin to overgrow and cause disease.

They may be caused by antibiotic resistant bacteria, i.e. Cephalosporin, Tetracycline.

Question 3

What are the 3 stages of the host-parasitic relationship?

Answer 3

Coloniization

Infection

Disease

Question 4

Where is normal biota (flora) found in our bodies?

Answer 4

skin/mucous membranes

gastrointestinal tract

respiratory tract

external ear canal

external eye

vagina

Question 5

What are the sterile anatomical sites in our bodies?

Answer 5

all internal tissues/organs:

liver, kidney, bladder, muscles, ovaries, glands, sinuses, ear

all fluids within tissues/organs:

urine, cerebrospinal fluid, saliva, semen, amnoitic fluid

Question 6

What is the Microbiome Project and how will it change our understanding of normal flora?

Answer 6

the Microbiome Project involves collecting genetic sequences in the gut (resp tract, skin, etc) to analyze their role of these microbes in human health & disease

Question 7

How does an antimicrobial antagonism help a human host?

Answer 7

Antimicrobial antagonism helps the human host by preventing overgrowth of harmful organisms

Question 8

Describe the difference between pathogenicity and virulence.

Answer 8

Pathogenicity describes bacterial species able to cause disease, while virulence is a degree of pathogenicity, but defines the relative severity of the disease.

Question 9

What are the 3 exceptions to Koch’s postulates?

Answer 9

1 infection genes b/c they are not readily isolated or grown in lab

2 viral diseases b/c they have a narrow host range

3 polymicrobial diseases b/c they are caused by a complex mixtures of microbes

Question 10

Describe the significance of opportunistic pathogens.

Answer 10

Opportunistic pathogens can cause disease in copromised individuals.

Question 11

What are 3 ways microbes can cause tissue damage?

Answer 11

1 enzymes

2 toxins

3 by inducing host’s defenses

Question 12

Describe some characteristics of Exotoxins.

Answer 12

Exotoxins are toxic in small amounts, they are specific to cell type, composed of protein, stimulate antitoxins, & can be denatured by heat (60 degrees C). They are also secreted from a live cell.

Question 13

Define some characteristics of Endotoxins.

Answer 13

Endotoxins are toxic in high doses, they are systemic, causing fever & inflammation, composed of lipopolysaccarides. They do NOT stimulate antitoxins, nor can they be dentaured by heat.

Question 14

Describe in order the steps microbes take to get to the point of causing disease.

Answer 14

1 They must find a portal of entry, i.e. skin, GI tract, endogenous biota.

2 They must attach firmly, using fimbriae, capsules.

3 Then must then survive the host’s defenses, hoping to avoid phagocytosis (death inside phagocyte).

4 At this time, then they can cause damage/disease.

Question 15

What portals of entry can be used for bacteria to enter the body?

Answer 15

They can enter through the skin, the gastrointestinal tract, the respiratory tract, and even the urogenital tract.

Question 16

What does “Infectious Dose” (ID) mean?

Answer 16

ID means the amount of pathogens (measured in number of microorganisms) required to cause infections in the host. For example, the ID for Q fever is only 1 cell, Tuberculosis is 10 cells, Chlorera is 1 milllion cells.

Question 17

Describe how drugs that target folic acid synthesis work.

Answer 17

They interfere with the folate metabolism by blocking enzymes required for synthesis of tetrahydrofolate. Tetrahydrofolate is needed by cells for folic acid synthesis and the production of DNA or RNA, and amino acids.

Question 18

Name an example of a “fluoroquinolone” drug.

Answer 18

Any drug ending in -floxacin. Some examples include Levofloxacin and Ciprofloxacin.

Question 19

Describe how biofilm differs from nonbiofilm when it comes to treament of infections?

Answer 19

Biofilms are unaffected by the same antimicrobials that work against them when they are free-living. There is a different phenotype that causes biofilm resistance.

Question 20

Name the 4 categories of antifungal agents.

Answer 20

1 azoles

2 echinocandins

3 flucytosine

4 macrolidepolyene antibiotics

Question 21

What are the 3 major “targets of action” of antiviral drugs?

Answer 21

1 bar penetration of virus into host

2 block transcription & translation of viral molecules

3 prevent maturation of viral particles

Question 22

What are 2 ways microbes can acquire antimicrobial resistance?

Answer 22

Microbes can become antimicrobial resistant by

1 spontaneous mutations of critical genes &

2 acquire an entire new genes via horizontal transfer from another species

Question 23

Describe 5 mechanisms microbes use to resist antimicrobials.

Answer 23

Microbes try to resist antimicrobials by

1 synthesizing new enzymes

2 descreasing the permeability of drug into bacterium

3 by immediately elminating the drug

4 by decreasing the number of binding sites

5 by shutting down or creating an alternative pathway for effective metabolic action to occur

Question 24

Describe the 4 antimicrobial strategies that are Under INVESTIGATION.

Answer 24

1 the strategy of targeting iron-scavenging capabilities of bacteria 2 RNA interference strategies 3 the strategy of mimicking molecules 4 the strategy of using bacteriophages to do the killing for us

Question 25

Describe the differences between toxic effects and allergic reactions.

Answer 25

Toxic effects are harmful and life-threatening, while allergic reactions are less threatening.

Question 26

Name 3 antimicrobials that inhibit protein synthesis.

Answer 26

1 aminoglycosides 2 tetracyclines 3 macrolides

Question 27

What does the basic structure of pencillin consist of?

Answer 27

beta-lactum ring

Question 28

What is beta-lactamases and how do they provide resistance against antibiotics?

Answer 28

Beta-lactamases are an enzyme that cleaves the beta-lactam ring (of penicillin & cephalosporin), thurs providing resistance against antibiotics.

Question 29

Name the antibiotic most effective against gram positive bacteria.

Answer 29

penicillin

Question 30

What are virulence factors?

Answer 30

microbe's structures/capabilities that allow it to establish in host & cause disease

Question 31

What are the defferences between endotoxins and exotoxins?

Answer 31

endotoxic released OUTSIDE cell; exotoxic released INSIDE cell

Question 32

Incubation-\>Prodromal-\>Period of Invasion-\>Convalescent Period

Answer 32

Stages of Disease in Humans

Question 33

administer drug to infected person, which destroys infective agent w/o harming the host cells

Answer 33

Antibacterial treatment

Question 34

used in treatment, relief, prophylaxis of disease

Answer 34

chemotherapeutic drug

Question 35

prevents imminent infection of person at risk

Answer 35

prophylaxis

Question 36

use of chemotherapeutic drugs to control infection

Answer 36

antimicrobial chemotherapy

Question 37

produced by natural metabolic processes of microorganisms that can inhibit/destroy other microorganisms

Answer 37

antibiotics

Question 38

chemically modified in lab after isolated from natural sources

Answer 38

semisynthetic drugs

Question 39

drug produced entirely by chemical reactions

Answer 39

synthetic drugs

Question 40

effective against limited microbial types, effective mainly on gram positive

Answer 40

narrow spectrum

Question 41

effective against wide variety of microbial types, effect against gram positive & negative

Answer 41

broad spectrum

Question 42

Define the difference between broad-spectrum and narrow-spectrum antimicrobials.

Answer 42

Broad-spectrum antimicrobials are effective against a larger number of bacteria, while narrow-spectrum antimicrobials target only a specific group.

Question 43

Define the 2 most selectively toxic drugs.

Answer 43

1 folic acid synthesis, because it blocks pathways and inhibits metabolism. 2 cell wall synthesis, because it blocks syntheis and repair.

Question 44

Name the 5 primary sites of action for antimicrobial agents.

Answer 44

The 5 primary sites are 1 cell wall synthesis 2 nucleic acid synthesis 3 cell membrane function 4 protein synthesis 5 action as antimeabolites

Question 45

Define selectively toxic.

Answer 45

It means causing harm to one organism without harming the other organisms.

Question 46

What is MIC?

Answer 46

MIC (Minimum Inhibitory Concentration) is the lowest concentration of antibiotic needed to inhibit bacterial growth in a test system.

Question 47

What is a cellular, infectious agent composed of RNA or DNA core and protein coat?

Answer 47

virus

Question 48

Which (broad or narrow) spectrum is effective against a wide variety of microbial types, including both gram positive and gram negative?

Answer 48

Broad-spectrum

Question 49

Which (broad or narrow) spectrum is effective against a limited number of microbial types, effective mainily on gram positive?

Answer 49

Narrow-spectrum

Question 50

Which drugs are produced entirely by chemical reactions, meaning they are chemically synthesized in a laboratory?

Answer 50

Synthetic drugs

Question 52

What are the goals of the Kirby-Bauer method (for testing anitmicrobial susceptibility)?

Answer 52

The Kirby-Bauer method (aka disk diffusion test) used to determine: 1 most effective agent for particular microbe 2 if organism is suspectible or resistant to antimircrobial agents

Question 53

What are the primary sources of antibiotoics?

Answer 53

fungi & bacteria

Question 54

What term means the characteristic of an ideal antimicrobial?

Answer 54

Microbicidal

Question 55

What term means using antimircrobial drugs to prevent infection?

Answer 55

prophylaxis

Question 56

What does a focal infection do?

Answer 56

It breaks loose from the initial infectionn and is carried to other tissues.

Question 57

Differentiate between sign and symptom.

Answer 57

Sign is objective evidence of disease, while symptoms are more subjective.

Question 58

What are endogenous infections are caused by?

Answer 58

They are caused by normal biota in an unusual state.

Question 59

What is an inatimate object that can transmit disease?

Answer 59

formite

Question 60

Name & describe the 2 sources of infectious agents.

Answer 60

1 exogenous-they originate from outside the body 2 endogenous-they already exist in/on the body

Question 61

List and explain the Kirby Bauer methods/steps.

Answer 61

1 surface of plate of specific medium is spread w/ the test bacterium, & small disks containing pre-meaured amounts of antibimircrobial are dispensed onto bacterial lawn 2 after INCUBATION, the zone of inhibition surrounding the disks if measured and compared with each standard for each drug 3 profile of antimicrobial sensitivity (aka anibiogram) provides data for drug selection

Question 62

How does the tube-dilution method (for testing antimicrobial susceptibility) work?

Answer 62

The antimicrobial is diluted into tubes of broth, then tubes are innoculated with small, uniform sample of pure culture, incubabted and examined for growth (turbidity)

Question 63

What means "the ratio of toxic dose to effective therapeutic dose that's used to assess safety/reliability of drug"?

Answer 63

Therapeutic index ++higher the index, the safer the drug++

Question 64

List and describe the three lines of defense (of the host).

Answer 64

1st line includes any barrier that blocks invasion at portal of entry 2nd line is a more internalized system of protective cells & flueds that includes inflammation and phagocytosis 3rd line is acquired on an individual basis as each foreign substance is encountered by white blood cells (lymphocytes). 3rd line provides long term immunity

Question 65

What are the 3 components of the first line of defense (of human host)?

Answer 65

1 chemical-secretions exert an antimicrobial effect, specialized glands of eyelids lubricate conjuctiva w/ antimicrobial secretion. Also lysozyme (found in saliva & tears) is an enzyme that hydrolyzes the peptiodoglycan in cell wall. 2 genetic-differences arise from mutations of genes that code for components, i.e. proteins, cytokines, T-cell receptors. 3 physical-skin/mucous-outtermost layer of skin composed of epithelial cells cemented together with keritrin, that results in a thick/tough layer that is highly impervious and waterproof.

Question 66

Define markers and their importance in the 2nd and 3rd lines of defense.

Answer 66

Markers generally consist of protein/sugars, & allow cells of the immunte system to identify whether the newly discovered cells are a threat.

Question 67

Name the 4 body compartments that participate in immunity.

Answer 67

1 reticuloendothelial system (RES) 2 extracellular fluid (ECF) 3 bloodstream 4 lymphatic system

Question 68

List the components of the reticulodendothelial (RES) system.

Answer 68

Network of _connective tissue fibers_ which provide a passageway between body compartments. It consists also fo the _thymus, lymph nodes, and spleen_. It is also called the mononuclear _phagocytic system_ because it is located where macrophages (which are derived from monocytes) are concentrated.

Question 69

What is the lymphatic system's structure consist of?

Answer 69

They lymphatic system consists of a branching network of vessels that extend into most body areas. The higher density of lymphatic vessels in the "dead end" areas of the hands, feet, and breast, are frequent contact points for infection. Other lymphatic organs include the lymph nodes, spleen, GALT, thymus gland & tonsils.

Question 70

What are 3 functions of the lymphatic system?

Answer 70

+main function is returnig lymph to circulation 1 they provide a route for the return of extracellular fluid to circulatory system 2 they act as a "drain off" system for inflammatory response 3 they render surveillance, recognition, & protection against foreign materials via a system of lymphocytes, phaygocytes, & antibodies.

Question 71

Name the 3 kinds of blood cells in the nonspecific immunity & their functions of each.

Answer 71

1 Neutrophils-active engulfers; killers of bacteria 2 Basophils-function in inflammatory events 3 Eosinophils-active in worm/fungal infections, allergy & inflammatory reactions

Question 72

Name 2 kinds of lymphocytes involved in specfic immunity; give description of each.

Answer 72

1 T Cells-assist B cells & killing foreign cells (cell-mediated immunity) 2 B Cells-differentiate into plasma cells and form antibodies (humoral immunity)

Question 73

List the 4 major categories of nonspecific immunity & give description of each.

Answer 73

1 phagocytosis-means "eating cell"; also actively attacks/dismantles foreign cells w/ a wide array of antimicrobial substances 2 inflammation-reaction to any traumatic event in tissues 3 fever-abnormally elevated body temp; inhibits multiplication of temp-sensitive microorganisms such as poliovirus, & funal pathogens. 4 antimicrobial proteins-interferon, complement, iron-binding, antimicrobial peptides

Question 74

Outline steps in phagocytosis.

Answer 74

++See diagram. 1 chemotaxis 2 adhesion 3 engulfment 4 phagosome 5 phagolysosome formation 6 killing/destrution of bacterial cells 7 release of residual depris

Question 75

Outline steps in inflammation.

Answer 75

1 injury//immediate reactions 2 vascular reactions 3 edema/pus formation 4 resolution/scar formation

Question 76

Discuss mechanism of fever.

Answer 76

Fever is initiated when circulating substances (pyrogens) reset the hypothalamic thermostat to a higher setting. This signals the musculature to increase heat production & peripheral arterioles to decrease heat loss via vasoconstriction.

Question 77

Name/describe 3 benefits of fever.

Answer 77

1 Fever _inhibits multiplication of temp-sensitive microorganisms_, such as poliovirus, cold viruses, herpes zoster virus, & systemic and subcutaneous fungal pathogens 2 Fever impedes the nutrition of bacteria by reducing _the availability of iron_. 3 Fever _increases metabolism_ & _stimulates immune reactions_ and naturally protective physiological processes.

Question 78

Name/describe 4 types of antimicrobial proteins.

Answer 78

1 interferon-involved in defenses against microbes, immune regulation, & intercommunication 2 complement-work together to destroy bacteria & certain viruses 3 iron-binding proteins-keeps iron bound tightly that it is not available for microbial use. Ex. Hemoglobin 4 antimicrobial peptides-insert themselves into prokaryotic membranes & kill microbes

Question 79

Give overview sentence about the purpose and mode of action of the complement system.

Answer 79

The complement system, named for its property of "complementing" immune reactions, consists of 26+ blood proteins that work in concert to destroy bacterial and certain viruses.

Question 80

Identify the sources for most currently used antimicrobials.

Answer 80

Bacteria in the genera Streptomyces and Bacillus Molds in the genera Penicillium and Cephalosporium