Microbiology -Chapter 21 (Microbial Diseases Of The Respiratory System)

Front 1

What are the parts of the upper respiratory system?

Back 1

• Upper respiratory system
o Nose
o Pharynx (throat)
o Middle ear and auditory tubes

Front 2

What are the parts of the lower respiratory system?

Back 2

• Lower respiratory system
o Larynx (voice box)
o Trachea (windpipe)
o Bronchial tubes
o Lungs (alveoli- sacs)

Front 3

Fill in the blank:
• Function of the respiratory system: ______________________

Back 3

• Function of the respiratory system: exchange of gases between the atmosphere and the blood

Front 4

What is the function of the upper respiratory system?

Back 4

• Upper Respiratory System: The normal Microbiota prevents the growth of pathogenic organisms. Some normal Microbiota are opportunistic pathogens

Front 5

What is the function of the lower respiratory system?

Back 5

• Lower respiratory system: typically microorganisms are not present

Front 6

“How the microbes are prevented from reaching the lungs?”

Back 6

• Particles (Microbes) are removed from larynx, trachea and bronchial tubes by ciliary escalator (first line of defense)
• Cilia propel particles upward
• Microbes reaching the lungs are removed by Phagocytosis

Front 7

what is the most common cold called?

Back 7

The common cold- Rhinitis

Front 8

Describe Rhinitis.

- cause
-transmission
- symptoms
- treatment

Back 8

• Caused by 200 different viruses
• Immunity is accumulated during the lifetime
• Symptoms: sneezing, nasal secretion, congestion
• Primary infection is in the throat but can spread to the lower respiratory system and the middle ear
• Virus is transmitted by air and hands to the nose mucous membrane
• Recovery time is about one week
• Antibiotics are not useful

Front 9

What is an ear infection called?

Back 9

Ear Infection- Acute Otitis Media”

Front 10

Acute Otitis Media results from what?

Back 10

Rhinitis

Front 11

Describe Ear Infection- Acute Otitis Media.

- cause
- symptoms
- effects
- treatment

Back 11

Result of rhinitis

•Viral infection causes inflammation of Eustachian tubes- accumulation of fluid

•Becomes the site of bacterial infection

•Treatment: Broad-spectrum antibiotics

Front 12

What is strep throat called?

Back 12

Streptococcal Pharyngitis

Front 13

Describe Streptococcal Pharyngitis

- cause
- symptoms
-effects
- treatment

Back 13

•Causative agent: Strepto.

•Symptoms: imflammation of the throat mucous membrane, lymph nodes (tonsillitis), difficulty swallowing

•May progress to scarlet or rheumatic fever and endocarditis

•Transmitted by respiratory secretion

•Treatment: antibiotics

Front 14

How is strep throat diagnosed?

Back 14

Strepto throat Diagnosis”
• Pharyngeal swab samples
• Blood agar streak
• Quick Strep: ELISA in a small tube… can be done in a physician’s office
• Only about 30% people diagnosed with Strep Throat actually have a S. pyogens
• Major problem- people recovering from Strep throat are contagious- even with antibiotic therapy

Front 15

what is S.pyogenes?

Back 15

- streptococcus pyogenes causes the most serious pharyngitis

Front 16

what are the virulence factors of S.pyogenes?

Back 16

“Virulence Factors of S. pyogens”
Includes:

•Polysaccharides- protection against lysozyme
•Lipoteichoic acid- adherence to epithelial cells in the pharynx
•M portion- a spiky surface projections- resistance against Phagocytosis
•Hyaluronic acid capsule- adherence
•Toxins- streptolysins- cytotoxic to tissue cells

Front 17

Describe
“Rheumatic Fever”

-treatment
-symptoms
- effects

Back 17

•May develop two to three weeks after a Group A streptococcal infection- strep throat

•Antibodies developed against streptococcal M protein may also react against the myocardium and joints

•Damage to heart valves

Front 18

Describe “Diptheria”

-cause
-symptoms
- effects
- treatment

Back 18

•Used to be the leading cause of fatal infectious diseases of children

•Caused by Corynebacterium diphtheria
oGr+ non-endospore irregular rods- pleomorphic morphology

•Symptoms: sore throat, fever, grayish membrane in the throat (can block the passage of air)

•Lysogenized bacteria produce powerful toxin

•Treatment: penicillin and erythromycin + antitoxin

•Vaccine available DTP

Front 19

what are the
“Virulence factors of Corynebacterium diphterae”

Back 19

•Exotoxin is the A-B toxin
•B (binding) component attaches to the receptor on the surface of the host cell
•The toxin enter the cell inside the endocytic vacuole
•Two components separate- A-chain enters the cytoplasm
•The active enzyme (chain A) inactivates EF-protein needed for protein synthesis
•Cell death follows

Front 20

What is whooping cough called?

Back 20

•Pertusis

Front 21

what is bacterial disease of the lower respiratory system?

hitn: there is only one.

Back 21

• Pertusis (Whooping Cough)

Front 22

describe Pertusis (Whooping Cough)

- cause
- symptoms
-effects
- treatment

Back 22

• Caused by Bordetella pertussis- aerobic Gr- coccobacili
• Bacteria affect the ciliated escalator system (prevent the movement of mucus)- mucus accumulates in trachea
• Infants can suffer from the brain damage caused by severe coughing
• Transmitted by droplets
• Treatment: combination antibiotic therapy
• Vaccine available- DTP

Front 23

What are the viral diseases of the lower respiratory system?

Back 23

- flu
-tuberculosis
-Pneumococcal pneumonia
-Legionellosis

Front 24

describe influenza.

-causes
-effects
-treatment

Back 24

• Caused by influenza virus
• The virus contains RNA (8 RNA segments), protein and lipid layer
• Lipid layer is holding two types of spikes (protein N and H)- antigens
• The immune response is directed towards these spikes

• The circulating virus must be identified in February- every year there is a different vaccine composition
• Contains three most important strains of virus
• The existing vaccine does not provide long-term immunity against all viral strains

Front 25

what is Antigenic shift?

Back 25

• Happens when ducks, swine and humans live together
• The swine harbors two different virus strains
• The ‘hybrid’ virus is formed- not recognized by the human immune system

Front 26

what are the Pathogenesis of flu?

Back 26

• Pathogenesis
o Symptoms chills, fever, headache, and muscular aches
o Flu patients are susceptible to secondary bacterial infections- damage to the lung epithelium

Front 27

what is the • Epidemiology of flu?

Back 27

• Epidemiology
o Influenza is transmitted via inhalation of airborne viruses
o Complications occur most often in the elderly, children, and those with chronic diseases
o 10000-20000 Americans die annually of the flu
o In 1918 epidemics 20 million people died

Front 28

describe Tuberculosis

-causes
- symptoms
-effects

Back 28

• Caused by Mycobacterium tuberculosis, Gr+ slender rods, sometimes filamentous
• Very resistant to drying and disinfectants (cell wall contains large amounts of lipids)
• Signs and symptoms
o Initial symptoms include minor cough and mild fever
o Later symptoms include difficulty breathing, chest pain, wheezing, and coughing up blood
o Long term (chronic) infection

Front 29

describe the infection process of tuberculosis.

Back 29

“Infection process”
Primary infection
• Bacilli penetrate the alveoli
• Macrophages ingest the bacterium (not always destroyed)
• M tuberculosis can survive inside the macrophage
• A layer of macrophages at the infection site is formed
• Tubercule may remain dormant for years
• The lesion may heal- BECOME CALCIFIED
• THE TUBERCULE MAY BECOME A SOURCE OF A NE INFECTION- secondary tuberculosis
• Tubercule grows forming air-filled cavity. Bacteria start multiplying outside the macrophages
• The disease is spread through aerosol droplets

Front 30

how is tubercuolosis diagnosed?

Back 30

“Tuberculosis Diagnosis”
• Tuberculin skin test- injection of a protein released by M. tuberculosis when grown in a liquid medium
• Tuberculin causes hypersensitivity reaction in the person who is infected with the M. tuberculosis
• Doesn’t distinguish between active disease, chronic carriers, or those who have been vaccinated
• Treatment: streptomycin, isoniazid, Rifampin, and pyarazin acid
• Six months antibiotic treatment (3-4 drugs)
• BCG vaccine- introduced in the 1920s (Bacillus of Calmette- Guerin)- live but virulent strain

Front 31

what is pneumonia?

Back 31

• Pneumonia- pulmonary infection

Front 32

describe Pneumococcal pneumonia

-causes
-symptoms
-effects
-treatment

Back 32

• Caused by Strepto. Pneumonia- Gr+ ovoid bacteria in pairs, thick capsule
• Infection of both bronchi and alveoli
• Symptoms: breathing difficulty, high fever, chest pain
• Bacteria can enter the blood stream and infect the meninges
• Treatment: Penicillin

Front 33

describe Legionellosis

-causes
-symptoms

Back 33

• Caused by: legionella pneumophila
• Discovered in 1976. Members of American Legion contracted pneumonia caused by unknown microbe
• L. pneumophila can be found in various natural environments, water lines, air conditioning systems, shower heads, decorative fountains
• Bacterium resistant to chlorine and high temperatures

Front 34

what is a fungal disease of the lower respiratory system?

Back 34

Histoplasmosis

Front 35

describe Histoplasmosis

- cause
-symptoms
-effects
- transmission

Back 35

• Infected lung shows lesions resembling tuberculosis
• In US the diseases is loacalized in Mississippi and ohio
• The disease is acquired by inhalation of airborne spores (bird droppings provide the favorable environment for the fungus)

Front 36

Describe the hitoplasmosis fungus.

Back 36

• Histoplasmosis capsulatum- dimorphic fungus
• When grown in soil and artificial media it forms filamentous mycelium
• When grown in tissue- produces yeast-like cells