Test 2 Flashcards
(86 cards)
1
Q
Concerning host-parasite relationships:
A
- Commensals may become parasitic, depending on location in body
- Normal flora of the G.I. tract may be mutualistic symbionts
- what may be “normal flora” for one person may cause disease in another
- Being immunocompromised may change the symbionic relationship
2
Q
Concerning the establishment of an infection:
A
Pathogens usually have virulence factors that promote colonization in tissues
3
Q
Concerning patterns of disease transmission:
A
Remember the five Fs (fingers, feces, food, flies, and fomites)
- House flies are major mechanical vecotrs of disease
- Beware of fomites such as combs, throat aerosols, blankets, and door-knobs
- food borne infections are most often due to poor personal or community hygiene
4
Q
Concerning staphylococcus spp.
A
These bacteria are serious agents of food poisoning
5
Q
Concerning TSST-1 exotoxin:
A
It is a prime example of a superantigen
6
Q
Concerning disease vectors:
A
As a general rule, pathogens transmitted by mosquitoes must have some portion of their life-cycle occur in the insect
7
Q
Heart valve damage
A
Strept viridans group
8
Q
Food poisoning
A
staphylococcus spp.
9
Q
Puerperal mastitis
A
Staphylococcus spp
10
Q
Exfoliatin
A
Scalded skin syndrome
11
Q
Which of the following is incorrect
Heart valve damage=strept viridans group
Food poisoning=streptococcus spp.
Puerperal mastitis=Scalded skin syndrome
A
B- Food poisoning = Staphylococcuss spp
NOT Streptococcus spp
12
Q
Erythrogenic toxin
A
Scarlatina
13
Q
Strept Exotoxin A
A
Necrotizing fasciitis
14
Q
Middle ear infection
A
Streptococcus pneumoniae
15
Q
TSST-1
A
Toxic Shock syndrome
16
Q
Which of the following are incorrect Erythrogenic toxin=Scarlatina Strept Exotoxin A=Necrotizing fasciitis Middle ear infection=Streptococcus pneumoniae TSST-1=Erythroblastosis fetalis
A
D- TSST-1 = Toxic shock syndrome
NOT Erythroblastosis fetalis
17
Q
Erysipelas
A
Strep. Pyogenes
18
Q
Acute glomerulonephritis
A
Strep-throat
19
Q
Nosocomial infection
A
Acquired in hospital
20
Q
Endogenous infection
A
Strept pneumonia
21
Q
Rheumatic fever
A
Strept throat
22
Q
Acute glomerulonephritis
A
Type 2 & 3 hypersensitivity
23
Q
Endocarditis
A
Strept viridans group
24
Q
This organism is the most important biological disease vector:
A
Mosquito
25
The establishment of an infection requires three main events or processes
1) Tissue invasion
2) Colonization
3) Immune Avoidance
26
Name four possible routes for endogenous infection
```
Anus to Urethra
Feces to mouth
Upper respiratory tract to lower respiratory tract
Moth to open woulnd
***
Anus-mouth
Mouth-damaged skin
Vaginal-blood stream(child birth)
Bowel-Abdomen, damage to the parietal layers
```
27
THe importance of an infectious disease can be determined by a specific relationship between 2 epidemiologic parameters...
Morbidity and Mortality
28
Give 3 characteristics of outdoor air that makes it generally less likely to transmit diseases than indoor air
1) Dryer
2) More UV rays
3) Ozone layer
29
Normal flora are bacteria that routinely grow on or in the body. Where in the body does one find the most different kinds of bacteria
The mouth, about 20 kinds
30
This man discovered the first antibiotics
Flemming
31
The research of these men made the discovery of antibiotics into a medical reality
Florey, Chain
32
Give 2 reasons why staphylococci are common cauces of nosocomial infections:
Health care workers have high carrier rates
| Patients in hospitals have weakened immune systmes
33
What specific characteristics of Strept and Staph are responsible for their reputation as pyogenic(puss forming) cocci:
They are puss forming cocci, because they produce enzymes and toxins that destroy tissue cells to form pus
34
This Strept virulence factor is responsible for aiding in establishing the infection, avoiding the immune response and some of the post-infection, immunologically-based complications...
M-Protein on fimbriae
35
What is the relationship between a furuncle and the staphylococcus virulence factor coagulase:
Coagulase creates a clot which will allow the bacteria to grow without letting an immune response in, causing a furuncle.,
36
What is the basis for the relatively "rapid" test for Streptococcus?
They will swab the throat adding it with latex beads and MAb. If the bacteria clots then the test is positive if it does not clot it is negative
37
Why are smokers and old people more susceptible to pneumonia due to Strept than UVU students:
Their immune system is compromised and their lungs are damaged
38
Why are all Gram-negative bacteria potentially pathogenic, What is the mechanism for their virulence?
Because of the LPS located on the cell surface and the glycocalyx
39
How do superantigens induce disease:
Through Poly-T cell stimulation- cross linking of MHC-II to CD4 hererodimer causing a cytokine cascade on interlukin-1, TNF and others. This results in a massive immune response that eventually leads to circulatory and repiratory collapse, Shock and death. Smooth muscles are always affected.
40
Staphylococcus food poisoning is a toxemia. What does this description denote, i.e. what is the difference between disease pathogenesis of toxemia and bacteremia(bacterial infections
Bacteremia- bacteria are present in disease state
| Toxemia- Bacteria have secreted toxins, but may not longer be present.
41
Give 3 examples of biological vectors:
Misquitoes
Flease
Ticks
Lice
42
Until recently, this antibiotic was the only one which cure hospital-acquired, often multiple antibiotic resistant infections of staphylococcus aureus:
Vancomycin
43
Name 2 post-streptococcal diseases, hypersensitive (auto-immune) diseases:
Acute glomerulonephritis
| Rhumatic fever
44
What are the general modes of action for penicillins
Inhibit cell wall synthesis
45
What are the general modes of action for Erythromycin:
Inhibits protein synthesis
46
What are the general modes of action for Sulfonamides:
Inhibits nucleic acid metabolism which takes away bacteria DNA synthesis
47
What is the general modes of action of Cephalosporins:
inhibit Cross-Linking of peptidoglycan
48
How do the anitbiotics which block protein synthesis distinguish between bacteria and human host cells.
Antibiotics alter the synthesis of 30s or 50s ribosomes present in 70s bacteria, human cells are 80s so they do not bind to human cells
This is because of the peptidoglycan that humans cells have
49
This term means a microoorganism is capable of causing disease
Pathogenic
50
This term means living together
Symbiotic
51
THis term refers to those situations resulting in disease
Parasitic
52
Name anti-microbial agents natural products derived from other micro-organisms:
Antibiotics
53
Sulfa drugs work by competitive inhibition of this vitamin _______ that bacteria use in the synthesis of their _______________
PABA
| DNA
54
Discruption of normal tissue, organ, or body functions is called
Disease
55
What are some of the advantages of the semisynthetic penicillins over penicillin G
Longer shelf life
Acid resistance
Broader spectrum
56
Why are all streptococcal infections aggressively treated:
They have devastating sequel diseases
| They are transmitted between family members
57
What is the difference between biological and mechanical vectors, and give and example of each
Biological- bacteria begin life cycle inside the vector (mosquito)
Mechanical- carry bacteria on body parts (house fly)
58
Name most serious disease cause by streptococcus spp, also known as "flesh-eating" strept:
Nacrotizing fascitis
59
What is the general treatment of Nacrotizing fascitis
Debulking/ penicillin
60
This epidermal infection, common in children and rapidly spread in classroom or day-care situations is often due to both staphylococcus and Streptococcus:
Impetigo
61
What is cellulitis:
Is a strp caused infection that affects deep tissues. Cuase when blood vessels are destroyed creating tissues "down stream" to slowly die. It can be septicemic and go though the whole body
62
Name the most common bacteria found on the skin.
Staphylococcus epidermitis
63
What is the difference between Pyrogenic and pyogenic exotoxins
Pyrogenic cause fever
| Pyogenic destroy tissue and form pus
64
What is the difference between Endogenous and Exogenous infections
Endogenous- cause by our own normal flora
| Exogenous cause by a foreign pathogen
65
This strept infection is due to its erythrogenic exotoxin:
Scarlet Fever
66
This bacteria species is responsible for both lung and ear infections:
Strept Pneumonia
67
Discuss the pathogenesis of pneumonia
When the S. pneumonia bacteria is introduced into the lungs, an immune response is quickly working in the body. The body forms exuadate which gets into the lungs through the blood stream & capillary exchange to the alveoli. This causes fluid in the lungs & pneumonia
68
SOme exotoxins damage blood vessles, especially capillaries, resulting in "down-stream" tissue necrosis. Explain how this pathology happens and which of the exotoxins we have dissuccussed might cause this damage
Exotoxin A causes damage to the blood vessels which then act like a tourniquet cutting off the blood supply to the tissue below resulting in tissue necrosis
69
WHat are "heart murmurs" and what group of bacteria we have discussed may cause this condition
Heart murmurs are cause by the heart valves not fully closing, causing blood to leak through in between contraction. THe staphylococcus saprophyticus bacteria is the cause when they colonize on the valves they become swollen and cant shut all the way
70
These exotoxins induce alterations in intestinal function, often leading to severe diarrhea:
Enterotoxins
71
THis bacteria species is the most common cause of food poisoning:
Staphylococcus aureus
72
What is the difference between a carbuncle and a furuncle:
Furuncle- one boil
Carbuncle- Bacteria has spread downward to sub q tissue resulting in larger affected area. THe spread horizonally under the epidermis.
73
Penicillin drug resistance is generally due to a bacterial-derived enzyme called
Penicillinace
74
This species of bacteria often colonizes artificial hearts valves, artificial joints:
Staphylococcus saprophyticus
| DOUBLE CHECK
75
THe most widely used antibiotic for Streptococus infections:
Penicillin
76
Subclinical
Infections with no apparent symptoms
77
Acute
Symptoms arise and subside rapidly
78
Endemic
Disease constantly present in a population
79
Pathogenesis
THe unfolding of the disease process
80
Epidemic
A significantly greater than expected number of cases
81
Pandemic
A worldwide epidemic
82
Latent
Dormant disease- pathogen is undetectable
83
Communicable
Capable of being transmitted
84
Reservoir
Source of infection disease
85
Zoonosis
Disease transmitted from animals to humans
86
Virulence
Degree of pathogenicity
