Lecture 13 Flashcards
(46 cards)
1
Q
Streptococcal pharyngitis / strept throat (Causative agent)
A
Streptococcus pyogenes, G+ cocci
2
Q
Streptococcal Pharyngitis (Transmission)
A
Respiratory droplets (airborne)
3
Q
Streptococcal Pharyngitis (Symptoms)
A
- Sore throat
- Swollen lymph nodes
- Pus-containing abscesses covering tonsils
- Fever but no runny nose
- Red pharyngeal tissue (from erosion)
4
Q
Streptococcal Pharyngitis (virulence factors)
A
- M protein (adhesion and block C3b thereby retarding phagocytosis)
- Streptokinase
- Streptolysins
5
Q
Streptococcal Pharyngitis (treatment)
A
- Penicillin (amoxicillin)
- Erythromycin
- Cephalosporin
6
Q
Streptococci (Classification)
A
- Using hemolytic properties
- plate bacteria on blood agar (cells will lyse b/c it produces B (beta) hemolysis)
- C substance
- serological test to determine the type of Carbohydrates on a bacteria surface
7
Q
Worst streptococci
A
Group A B (beta) hemolytic
8
Q
Scarlet Fever (causative agent)
A
S. Pyogenes infected with bacteriophage
- which then produces erythrogenic toxin
9
Q
Scarlet Fever (symptoms)
A
- Red rash caused by blood leaking through walls of capillaries damaged by erythrogenic toxin
10
Q
Erysipelas (causative agent)
A
- dermal Streptococcus
11
Q
Erysipelas (symptoms/occurs primarily in…)
A
- painful red rash recur periodically at the same body site
- occurs primarily in infants and people above 30
12
Q
Necrotizing Fasciitis (causative agent)
A
streptococcal infection of sheath covering the skeletal muscles
13
Q
Necrotizing Fasciitis (symptoms)
A
dissolving of flesh
14
Q
Necrotizing Fasciitis (treatment)
A
- removal of dead tissue
- amputation
15
Q
Diphtheria (Causative agent)
A
- Corynebacterium diphtheriae G (+) with metachromatic granules
16
Q
Diphtheria (transmission)
A
- inhaling respiratory droplets near tonsils
17
Q
Diphtheria (symptoms)
A
- sore throat, fever
- pseudomembrane
- made of mucus, dead cells, and fibrous material (resulting in respiratory blockage)
18
Q
Diphtheria (identification)
A
- Corynebacterium diphtheriae is a G+ rod with metachromatic granules
- Palisade arrangment
- clumping of bacteria rods
19
Q
Diphtheria (virulence factor)
A
- exotoxin (A/B) encoded by lysogenic corynephage
- B: binds to human growth factor receptor triggering endocytosis
- A: blocks protein synthesis
20
Q
Diphtheria (treatment)
A
- antitoxin
- to immediately neutralize the diphtheria toxin
- penicillin or erythromycin
- tracheostomy (if pseudomembrane has completely blocked airway)
- DTaP vaccine
21
Q
Pertussis / whooping cough (causative agent)
A
- Bordetalla pertussis
- - G - coccabacillus, aerobis
22
Q
Pertussis (transmission)
A
- inhaled in aerosols
- mostly infects children
23
Q
Pertussis (symptoms)
A
Stage 1: catarrhal - inflammation of mucous membrane
Stage 2: paroxysmal - severe coughing spasms that leave child gasping for air between coughs
24
Q
Pertussis (virulence factor)
A
3 toxins:
- Filamentous hemagglutinin: acts as an adhesin
- Pertussis toxin: AB toxin disrupts cAMP signaling and induces increased mucus production
- Tracheal cytotoxin: damages ciliated cells
25
Pertussis (symptoms)
paroxysmal stage
26
Pertussis (treatment)
- DTaP vaccine
| - bacteria are usually gone by paroxysmal stage, so treatment is supportive care and allow body to self heal
27
Tuberculosis (causative agent)
Mycobacterium tuberculosis
| acid-fast G+ rods
28
Tuberculosis (transmission)
- inhalation of respiratory droplets
29
Tuberculosis (Virulence factor)
- Mycolic acid
- - protection from phagocytosis
- - resistance to Gram stain, detergents, antimicrobial drugs, desiccation
- Cord factor
- - prevents phagosome-lysosome fusion (doesn't get metabolized by macrophage)
- - type of lipid that allows daughter cells to remain attached to one another
- formation of tubercle
30
Tuberculosis (three types)
1. Primary tuberculosis
- - most people experience fever and weight loss (small % experience severe coughing, chest pain)
2. Secondary tuberculosis
- - tubercle breaks and spreading lungs
3. Miliary/Dissemiinated tuberculosis
- - bacteria spreads in body and eats the tissue
31
Tuberculosis (diagnosis)
- detection of M. tuberculosis in sputum sample
- will give positive result if infected with tuberculosis or is vaccinated for tuberculosis
- follow up chest x-ray to check for presence of tubercle
32
Tuberculosis (treatment)
- Isoniazid, rifampin, ethambutol
- DOTS: directly observed treatment shortcourse (people come to your house and harras you to take meds)
- Immunization with BCG vaccine (live attenuated)
33
Pneumonia (causative agent)
- pneumonia is not a disease, it is a collection of specific symptoms
- most common causative agent: streptococcus pneumoniae (G+ encapsulated)
34
Pneumonia (transmission)
- part of normal flora
- usually a secondary infection
- becomes opportunistic parasite
35
Pneumonia (virulence factors)
- Pneumolysin O
- - lysis of choloestrol lined cells
- capsule prevents phagocytosis
- IgA proteases
- - destroyes IgA in mucus
36
Pneumonia (treatment)
- penicillin
- macrolide of fluoroquinolone
- vaccination
37
Other Pneumonias
- Klebsiella pneumoniae – G- rod
- Haemophilus influenzae, - G- pleomorphic (opportunistic parasite)
- Staphylococcus aureus – G +
38
Primary Atypical Pneumonia (walking pneumonia)
| [cauative agent]
Mycoplasma pneumoniae, no cell wall-pleomorphic, one of the smallest bacteria to cause human disease
39
Primary Atypical Pneumonia (walking pneumonia) primarly seen in
occurs in healthy people mainly high school and college students
40
Primary Atypical Pneumonia (walking pneumonia) symptoms
- excessive sweating
- fever
- dry hacking cough
- sore throat
- fatigue
41
Primary Atypical Pneumonia (walking pneumonia) treatment
erythromycin or tetracycline, but not penicillin because no cell wall
42
Legionnaire’s Disease (Legionellosis) causative agent/diagnosis
Legionella pneumophila, G- rod
- using buffered charcoal yeast
43
Legionnaire’s Disease (Legionellosis) transmission
- exists where water collects- air conditioners, puddles, humidifiers
- Person-to-person transmission is uncommon
44
Legionnaire’s Disease (Legionellosis) symptoms
- Fever, dry cough, headache
| - Also, complications of GI tract, nervous system, liver, or kidney
45
Legionnaire’s Disease (Legionellosis) pathogenicity
- Intracellular parasite of macrophages/other cells
| - Causes tissue destruction and inflammation of the lungs
46
Legionnaire’s Disease (Legionellosis) treatment
- Treat water source with chlorine or heat
recognition using special yeast extract agar (fluoresces on agar)
- Fluoroquinolones or macrolides
