chapter 24 Microbial disease of the Respiratory System

Question 1

1. Are potential pathogens a part of the upper respiratory system’s normal Microflora?
2. Why do potential pathogens not cause disease normally>?

Answer 1

1. yes

2. Predominant microflora inhibit growth through competition for food and they make inhibitory substances.

Question 2

What are some predominant microflora in the respiratory system that start with an S?

Answer 2

Staphylococci and streptococci

Question 3

Predominant microflora that are aerobic, start with an H and an N?

Question 4

What causes the lower respiratory system to be nearly sterile?

Answer 4

ciliary elevator

Question 5

A gram + bacterial group consists soleley of streptococcus pyogenes that is an infection in the upper respiratory system is called?

It is resistant to phagocytosis

Answer 5

Streptococcal pharyngitis

Question 6

What are the functions of streptokinases and streptolysins?

Answer 6

Streptokinases lyse clots and streptolysins are cytotoxic to tissue cells, rbc and protective leukocytes

Question 7

How is Streptococcal Pharyngitis diagnosed?

Answer 7

EIA or enzyme immunoassay tests

Question 8

S. pyogenes also causes this infection besides strep throat?

Answer 8

Scarlet fever- S.pyogenes causes the production of a reddening toxin (Erythrogenic toxin)

Question 9

Erythrogenic toxin is a blank strain

Answer 9

lysogenic

Question 10

Organism responsible for Diphtheria?

Answer 10

Corynebacterium diphtheriae- gram + rod

Question 11

Diphtheria toxin is not produced by lysogenized C. diphtheriae?

An immunization that helped preven this infection is known as ?

Answer 11

False: It is

DTaP vaccine

Question 12

1. Infection of the middle ear is called….

2. what is the most common organism that causes it?

Answer 12

1. Otitis media

2. S.pneumoniae (35%)

Question 13

There are two other organisms that start with an S. besides S. pneumoniae that cause Otitis media. What are they?

Answer 13

S. pyogenes (8-10%)

S. aureus (1-2%)

Question 14

what bacterium that starts with an H. causes an ear infection?
What has helped reduce ear infections by the S. pneumoniae?
Virus is not a reason as to why an ear infection would occur?

Answer 14

Haemophilus influenzae (20-30%)
reduced by vaccine
False: 3-5% of viruses cause ear infections

Question 15

Are there more than one virus that helps the cause of a common cold? Name some
There are no viruses without causative agent?

Answer 15

rhinoviruses 50%
Coronaviruses 15-20%
other viruses 10% roughly

False: 40% of viruses have no causative agent

Question 16

Common occurrence of colds with people are….

A single rhinovirus is infective for airborne transmission?

Answer 16

people tend to accumulate resistance
fewer colds as we get older

True

Question 17

Antibiotics work excellent on viruses?

There is not much someone can do to shorten period of symptoms?

Answer 17

False: Anti. biotics do not work well on viruses

True

Question 18

Gram - coccobacillus is what kind of organism that causes whooping cough?

It has a capsule

Has Tracheal cytotoxin of cell wall damages ciliated cells

Answer 18

Bordetella pertussis

Question 19

toxin of whooping cough that starts with a P?

What prevents whooping cough and what is it made of?

Answer 19

Pertussis toxin

prevented by DTaP - acellular Pertussis cell fragments

Question 20

Caused by Streptococcus pneumoniae?

It is a Gram + encapsulated diplococci

Answer 20

Pneumococcal Pneumonia

Question 21

Symptoms: Infected alveoli of lung fill with fluids; interferes with oxygen uptake
Diagnosis: Optochin-inhibition test or bile solubility test; serological typing of bacteria
Treatment: Penicillin, fluoroquinolones
Prevention: Pneumococcal vaccine

Answer 21

Pneumococcal Pneumonia

Question 22

Gram-negative coccobacillus
Predisposing factors: Alcoholism, poor nutrition, cancer, or diabetes
Symptoms: Resemble those of pneumococcal pneumonia
Diagnosis: Isolation; special media for nutritional requirements
Treatment: Cephalosporins

Answer 22

Haemophilus influenzae Pneumonia

Question 23

Primary atypical pneumonia; walking pneumonia
Mycoplasma pneumoniae
Pleomorphic, wall-less bacteria
Common in children and young adults

Answer 23

Mycoplasmal Pneumonia

Question 24

Symptoms: Mild but persistent respiratory symptoms; low fever, cough, headache
Diagnosis: PCR and serological testing
Treatment: Tetracyclines

Answer 24

Mycoplasmal Pneumonia

Question 25

Legionella pneumophila
Gram-negative rod
Found in water
Transmitted by inhaling aerosols; not transmitted from human to human

Symptoms: Potentially fatal pneumonia that tends to affect older men who drink or smoke heavily
Diagnosis: Culture on selective media, DNA probe
Treatment: Erythromycin

Answer 25

Legionellosis

Question 26

Common in infants; 4500 deaths annually
Causes cell fusion (syncytium) in cell culture
Symptoms: Pneumonia in infants
Diagnosis: Serological test for viruses and antibodies
Treatment: Ribavirin, palivizumab

Answer 26

Respiratory Syncytial Virus (RSV)

Question 27

Symptoms: Chills, fever, headache, and muscle aches
No intestinal symptoms
1% mortality, very young and very old
Treatment: Zanamivir and oseltamivir inhibit neuraminidase
Prophylaxis: Multivalent vaccine

Answer 27

Influenza (Flu)

Question 28

Hemagglutinin (HA) spikes used for attachment to host cells

Neuraminidase (NA) spikes used to release virus from cell

Answer 28

The Influenza Virus

Question 29

Antigenic shift
Changes in HA and NA spikes
Probably due to genetic recombination between different strains infecting the same cell
Antigenic drift
Point mutations in genes encoding HA or NA spikes
May involve only 1 amino acid
Allows virus to avoid mucosal IgA antibodies

Answer 29

The Influenza Virus