Lecture 15 Flashcards
(33 cards)
1
Q
Acne (causative agent)
A
- Propionibacterium acnes
- Gram-positive, rod-shaped
- Commonly found on the skin
- Named for the carbohydrate by produce fermentation: propionic acid
2
Q
Acne (formation)
A
- proprionic bacteria uses sebum as food source (grows on sebum)
- when there is more sebum, more bacteria is able to colonize and infect pores
3
Q
pustules
A
- infected pore by Propionibacterium acnes
4
Q
Acne (treatment)
A
- Benzoyl peroxide
- causes exfoliation of skin cells,
- doxycycline
- antibiotic
- Acutance (retinoid acid)
- inhibits production of sebum
- cannot be used when pregnant
- light treatment
- 405-420
5
Q
Staphylococcal Infections (two major bacteria)
A
- Staphylococcus aureus
- More virulent strain b/c this one has ALL the virulence factors
- Variety of conditions depending on site of infection
- Staphylococcus epidermidis
- Opportunistic infections
- only virulence factors are lipase and polysaccharide slime layer
6
Q
Staphylococcus enzymes (virulence factors)
A
- coagulase, and Staphylokinase
- coagulase helps induce blood clot (helps bacteria evade cell immunity)
- Staphylokinase dissolves blood clot
- Lipases
- helps Digest lipids, allow staphylococcus to grow on skin and in oil glands
- β-lactamase
– cleaves β-lactam ring
inhibiting penicillin type antibiotics
7
Q
Staphylococcus toxins (virulence factors)
A
- Staphylolysins
- -Disrupts the cytoplasmic membrane of a variety of cells
- Leukocidin
- can lyse leukocytes specifically
- Exfoliative toxins
- Cause skin cells to separate and slough off
- Toxic-shock syndrome toxin
- Causes toxic shock syndrome
- Enterotoxins
- Stimulate symptoms associated with food poisoning
8
Q
Cutaneous Diseases (causative agent)
A
Staphylococcus
9
Q
Cutaneous Diseases (virulence/pathogenicity)
A
- exfoliated toxins destroy desmosome
- - destroying skin connective tissue
10
Q
Cutaneous Diseases (treatment)
A
- treat with drugs designed to resist β-lactamase
- - ex: methicillin
11
Q
Toxic Shock Syndrome (causative agnet)
A
- Toxic Shock Syndrome
- usually caused by leaving tampons in too long
- potentially fatal within hours
12
Q
Gas Gangrene (causative agent)
A
- Clostridium perfringens
- G+ anaerobic rod
- spore former
- obligate anerobic
13
Q
Gas Gangrene (transmission)
A
- Infects damaged/dying tissue
- since C. perfringens is ubiquitous
14
Q
Gas Gangrene (symptoms)
A
- pain from infected wound, increased swelling
- foul odor and frothy fluid from bacterial invasion of dead, anaerobic tissue
- bacteria consume human muscle carbs/protein
- crepitation (popping of skin via gas pockets)
15
Q
Gas Gangrene (pathogen/virulence factor)
A
- exotoxin:
- Lecithinase (dissolves cell membrane and releases toxic cellular enzymes)
- hyaluronidase (breaks down junction between cell for further invasion) this creates a positive feed back
- hemolysin
16
Q
Gas Gangrene (treatment)
A
- Penicilin
- Removal of dead and damaged tissue (amputation/Debridement)
- Hyperbaric oxygen chamber (where O2 concentratin is greater than normal)
- killing the anaerobic bacteria
17
Q
Cutaneous Anthrax (causaive agent)
A
- Bacillus anthracis
- Gram+, spore-forming rod
18
Q
Anthrax (Transmission)
A
- from animal
- inoculation of spores into skin
- may be bioterrorism (aerosolized fine powder)
19
Q
Anthrax (three types)
A
- Pulmonary or inhalation (inhalation of spores)
- Wool sorter’s disease
- Gastrointestinal (consumption of contaminated meat)
- Cutaneous (inoculation of spores into cuts in skin)
20
Q
Anthrax (Symptoms)
A
- bloody black fluid resulting from tissue damage
- black-crusted lesions (cutaneous)
- violent dysentary (GI anthrax)
21
Q
Anthrax (pathogenicity/virulence factor)
A
- Spores germinate on contact w/human tissues
- Thick capsule on cells protects cell from phagocytize
- Anthrax toxin
22
Q
Anthrax toxin
A
- Protective antigen (PA)
- Binds to human cells – facilitates binding of EF and LF
- Edema factor (EF)
- EF converts ATP to cAMP, cAMP overproduced
- cAMP –intracellular signaling molecule—things in cell go crazy with too much cAMP
- Lethal factor (LF)
- Causes death of human cells (apoptosis)
23
Q
Anthrax (treatment)
A
- penicillin (ciprofloxacin or doxycycline are given if bacteria are resistant to penicillin)
- Remove spores from contaminated area by burying them in lime or incinerating them
- formaldehyde
- vaccine (inactivated vaccine)
- only for frontline (army)
24
Q
Rocky Mountain Spotted Fever (causative agent)
A
- Rickettsia rickettsii, small G (-)
- Intracellular parasite
25
Rocky Mountain Spotted Fever (transmission)
- biological vectors
| - - Ticks such as Dermacentor variabilis
26
Rocky Mountain Spotted Fever (diagnosis)
- agglutination test
- - using porteus O and infected individual's antibodies b/c
- - since RMS and porteus O have the same lipid O molecule
- - the antibody will bind to porteus O in agglutination test
27
Rocky Mountain Spotted Fever (symptoms)
- high fever, spotted rash-
Maculopapular (petechial)
- rash from extremities to trunk
28
Rocky Mountain Spotted Fever (treatment)
- tetracycline
| - chloramphenicol
29
Typhus (Causative Agent)
- Rickettsia prowazekii
30
Typhus (trasmission)
- Biological vector
| Pediculus humanus: body lice
31
Typhus (Pathogenicity)
?? find out more
32
Typhus (Symptoms)
- maculopapular rash (trunk to extremities – opposite of RMSF)
- 104°F fever causes hallucinations/delirium
33
Typhus (diagnosis/treatment)
- diagnosis
- - Weli Felix test (more?)
Antibiotics
-- tetracycline, chloramphenico
