Chapter 24- Microbial Diseases Of The Respiratory System

Front 1

Anatomical defenses of Upper Respiratory System?

Back 1

course hairs, mucus secreting cells, cilia, tonsils - lymphoid tissue

Front 2

Laryngitis and tonsillitis caused by?

Back 2

Streptococcus pneumoniae, Streptococcus pyogenes,viruses - can often work in combination - usually self-limiting (i.e., recovery will usually occur without medical intervention)

Front 3

Epiglottitis caused by?

Back 3

Haemophillus influenzae - most threatening disease of the URS, Hib vaccine has significantly reduced the number of cases

Front 4

Strep throat caused by?

Back 4

Streptococcus pyogenes - group A beta-hemolytic
Resistant to phagocytosis
Streptokinases lyse clots
Streptolysins are cytotoxic
Diagnosis by indirect agglutination - uses latex particles coated with antibodies against group A streptococci

Front 5

Scarlet Fever caused by?

Back 5

Streptococcus pyogenes
Erythrogenic toxin produced by lysogenized S. pyogenes - reddening toxin causes red skin rash and high fever

Front 6

Diptheria caused by:

Back 6

Corynebacterium diptheriae; gram postive rod

Front 7

Diphtheria was the leading infectious killer of children until?

Back 7

Leading infectious killer of children until 1935

Front 8

What has a membrane that can block the air passage?

Back 8

Diphtheria membrane of fibrin, dead tissue, and bacteria - can totally block air passage

Front 9

Diphtheria toxin produced by? and the toxin does what?

Back 9

Diphtheria toxin produced by lysogenized C. diphtheriae - toxin interferes in protein synthesis

Front 10

Diptheria prevented by?

Back 10

Prevented by DTaP and Td vaccine (Diphtheria toxoid, inactivated toxin that elicits an immune response)
Effective treatment requires antibiotics and antitoxin

Front 11

Cutaneous diphtheria:

Back 11

Infected skin wound leads to slow healing ulcer

Front 12

Otitis Media:

Back 12

Infections of the middle ear - account for nearly one half of office visits to pediatricians, affects 85% of children before the age of three

Front 13

Causes and percentages of Otitis Media?

Back 13

S. pneumoniae (35%)
H. influenzae (20-30%)
M. catarrhalis (10-15%)
S. pyogenes (8-10%)
S. aureus (1-2%)

Front 14

Otitis Media is treated with?

Back 14

Treated with broad-spectrum antibiotics
Incidence of S. pneumoniae reduced by vaccine

Front 15

The Common Cold:

Back 15

Viral disease of the URS; most prevalent disease of humans in the temperate zones (kids: 6-8 colds/year, and adults: 2-4 colds/yr)

Front 16

What causes the common cold?

Back 16

More than 200 agents cause the common cold

Rhinoviruses (50%) - at least 113 serotypes
A single virus particle can cause a cold
Almost all Rhinoviruses attached to ICAN-1 on nasal mucosa of host cells - possible mechanism for control

Coronaviruses (15-20%)

Front 17

Lower respiratory system?

Back 17

Larynx, trachea, bronchial tubes, alveoli
The ciliary escalator keeps the lower respiratory system sterile
Aveolar macrophages - destroy microorganisms that reach the lung

Front 18

Bacteria, viruses, & fungi cause in the Lower Respiratory System:

Back 18

Bacteria, viruses, & fungi cause:
Bronchitis
Bronchiolitis
Pneumonia

Front 19

Pertussis (whooping cough) caused by?

Back 19

Bordatella pertussis: gram neg. coccobacillus, capsulated

Attach to ciliated cells in the trachea

Tracheal cytotoxin of cell wall damages ciliated cells

Pertussis toxin - enters bloodstream, causese symptoms of disease

Front 20

Pertussis prevented by?

Back 20

Prevented by DTaP vaccine (acellular Pertussis cell fragments)

Front 21

Pertussis' 3 stages?

Back 21

Stage 1: Catarrhal stage: like common cold
Stage 2: Paroxysmal stage: Violent coughing sieges
Stage 3: Convalescence stage: may last for months

Front 22

Tuberculosis caused by:

Back 22

Mycobacterium tuberculosis: acid-fast rod that is transmitted from human to human.

Front 23

Mycobacterium Tuberculosis generation time?

Back 23

>20 hours

Front 24

M. bovis:

Back 24

M. bovis: <1% U.S. cases, not transmitted from human to human

Front 25

M. avium-intracellulare:

Back 25

M. avium-intracellulare - infects people with late stage HIV infection

Front 26

Stages of Tuberculosis:

Back 26

1. bacilli is inhaled and reach the alveoli of the lung
2. ingested by a macrophage but survives
3. bacilli multiply in macrophages and cause a chemotactic response (start of tubercule)
4. after a few weeks, disease symptoms appear as many macrophages die, releaseing tubercule bacilli and forming a caseous center in the tubercule.
5. liquefication=caseous center enlarges and forms tuberculous cavity
6. tubercule ruptures and bacilli spill into bronchioles and diseminate throughout the lung, circulatory, and lymphatic systems.

Front 27

Treatment of Tuberculosis:

Back 27

Prolonged treatment with multiple antibiotics - bacilli are slow growing and may be hidden in macrophages or locations difficult to reach with antibiotics
Vaccines: BCG, live, avirulent M. bovis. Not widely used in U.S

Front 28

Diagnosis of Tuberculosis

Back 28

Diagnosis: Tuberculin skin test screening
+ = current or previous infection
Followed by X-ray, acid-fast staining of sputum, culturing bacteria

Front 29

Pneumococcal Pneumonia caused by:

Back 29

Streptococcus pneumoniae: Gram-positive encapsulated diplococci
Most common - typical pneumonia

Front 30

Diagnosis and Treatment of Pneumococcal Pneumonia?

Back 30

Diagnosis by culturing bacteria
Penicillin is drug of choice - antibiotic resistance is becoming a problem

Front 31

Haemophilus influenzae Pneumonia? Predisposing factors?

Back 31

Gram-negative coccobacillus

Alcoholism, poor nutrition, cancer, or diabetes are predisposing factors

Front 32

Haemophilus influenzae Pneumonia treatment?

Back 32

Second-generation cephalosporins = drugs of choice

Front 33

Mycoplasmal Pneumonia caused by?

Back 33

Mycoplasma pneumoniae: pleomorphic, wall-less bacteria

Front 34

Mycoplasmal Pneumonia also called?

Back 34

Also called primary atypical pneumonia and walking pneumonia

Front 35

Mycoplasmal Pneumonia common in what age group? and how do you diagnose?

Back 35

Common in children and young adults
Diagnosis by PCR or by IgM antibodies

Front 36

Legionellosis caused by?

Back 36

Legionella pneumophila: Gram-negative rod

Front 37

L. pneumophila found where? and how is it trasmitted?

Back 37

L. pneumophila is found in water
Transmitted by inhaling aerosols, not transmitted from human to human

Front 38

Diagnosis and Treatment of Legionellosis?

Back 38

Diagnosis: culturing bacteria
Treatment: Erythromycin

Front 39

Psittacosis (Ornithosis) caused by?

Back 39

Chlamydia psittaci: gram-negative intracellular bacterium associated with birds such as parakeets and parrots

Front 40

Psittacosis (Ornithosis) transmitted by?

Back 40

Transmitted by elementary bodies from bird dropping to humans

Front 41

What reorganizes into reticulate body after being phagocytized?

Back 41

Psittacosis (Ornithosis)

Front 42

Diagnosis and Treatment of Psittacosis (Ornithosis)?

Back 42

Diagnosis: culturing bacteria in eggs or cell culture
Treatment: Tetracycline

Front 43

Chlamydial Pneumonia caused by?

Back 43

Chlamydia pneumoniae
Resembles mycoplasmal pneumonia
Transmitted from human to human

Front 44

Chlamydial Pneumonia transmitted by?

Back 44

Transmitted from human to human

Front 45

Diagnosis and Treatment of Chlamydial Pneumonia?

Back 45

Diagnosis by FA test
Treatment: Tetracycline

Front 46

Q fever caused by? transmitted by? Who is most at risk?

Back 46

Coxiella burnetti: obligate, intracellular bacterium
Can survive airbourne transmission(has an endospore like body)
Inhaling a single pathogen can cause infection
Workers in dairy and meat processing plants are most at risk

Front 47

Viral Pneumonia (LRS)?

Back 47

can occur as a complication of influenza, measles, chickenpox

Viral etiology suspected if no cause determined

Front 48

Respiratory Synctial Virus (RSV)?

Back 48

Common in infants; 4500 deaths annually
Causes cell fusion (syncytium) in cell culture
Symptoms: coughing and wheezing
Diagnosis by serologic test for viruses and antibodies

Front 49

Influenza symptoms and mortality?

Back 49

Chills, fever, headache, muscle aches (no intestinal symptoms)
1% mortality due to secondary bacterial infections

Front 50

Treatment of Influenza?

Back 50

Treatment: Amantadine
Vaccine for high-risk individuals

Front 51

Structure of Influenza Virus:

Back 51

8 separate RNA segments of different lengths
enclosed by inner layer of protein (capsid)
outer lipid bilayer-which contains H and N spikes

Front 52

H spikes:

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Hemagglutinin (H) spikes used for attachment to host cells

Front 53

N spikes:

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Neuraminidase (N) spikes used to release virus from cell

Front 54

Antigenic shift:

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Changes in H and N spikes
Probably due to genetic recombination between different strains infecting the same cell

Front 55

Antigenic drift:

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Mutations in genes encoding H or N spikes
May involve only 1 amino acid
Allows virus to avoid mucosal IgA antibodies

Front 56

Influenza serotypes:

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A: causes most epidemics, Antigenic subtypes = H3N2, H1N1, H2N2
B: moderate, local outbreaks
C: mild disease

Front 57

Histoplasmosis caused by? transmitted by?

Back 57

Histoplasma capsulatum; dimorphic fungus
Transmitted by airborne conidia from soil - >75% of population in affected areas have antibodies

Front 58

Diagnosis and Treatment of Histoplasmosis?

Back 58

Diagnosis by culturing fungus
Treatment: amphotericin B

Front 59

Coccidioidomycosis caused by? and Life cycle?

Back 59

Cocciodioides immitis
arthrospore grows into tubular hypha --> hypha segments into arthrospores-->arthrospores inhaled -->inhaled arthrospore (how they are transmitted) grows into spherule-->endopores grown inside spherule-->spherule releases endospores

Front 60

Diagnosis and Treatment of Coccidioidomycosis?

Back 60

Diagnosis by serological tests or DNA probe
Treatment: amphotericin B

Front 61

Pneumocystis Pneumonia caused by?

Back 61

Pneumocystis jiroveci (P. carinii) found in healthy human lungs (once thought to be a protozoan but now identified as a fungus)

Front 62

Pneumocystis Pneumonia occurs in?

Back 62

Pneumonia occurs in newly infected infants & immunosuppressed individuals (had become a primary indicator of AIDS)

Front 63

Pneumocystis Pneumonia treated by?

Back 63

Treatment: Timethoprim-sulfamethoxazole

Front 64

Pneumocystis life cycle:

Back 64

Mature cyst contains intracystic bodies-->cyst ruptures releasing bodies-->bodies develop into trophozites-->trophozites divide-->trophozites develop into a cyst.

Front 65

Blastomycosis caused by?

Back 65

Blastomyces dermatitidis, dimorphic fungus
Found in soil

Front 66

Blastomycosis causes? treatment?

Back 66

Can cause extensive tissue destruction
Treatment: amphotericin B

Front 67

Opportunistic fungi involved in respiratory disease:

Back 67

Aspergillus
Rhizopus
Mucor

Front 68

What requires both antibiotics and an antitoxin?

Back 68

Diphtheria