chapter 24 Microbial disease of the Respiratory System Flashcards
- Are potential pathogens a part of the upper respiratory system’s normal Microflora?
- Why do potential pathogens not cause disease normally>?
- yes
2. Predominant microflora inhibit growth through competition for food and they make inhibitory substances.
What are some predominant microflora in the respiratory system that start with an S?
Staphylococci and streptococci
Predominant microflora that are aerobic, start with an H and an N?
What causes the lower respiratory system to be nearly sterile?
ciliary elevator
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
Streptococcal pharyngitis
What are the functions of streptokinases and streptolysins?
Streptokinases lyse clots and streptolysins are cytotoxic to tissue cells, rbc and protective leukocytes
How is Streptococcal Pharyngitis diagnosed?
EIA or enzyme immunoassay tests
S. pyogenes also causes this infection besides strep throat?
Scarlet fever- S.pyogenes causes the production of a reddening toxin (Erythrogenic toxin)
Erythrogenic toxin is a blank strain
lysogenic
Organism responsible for Diphtheria?
Corynebacterium diphtheriae- gram + rod
Diphtheria toxin is not produced by lysogenized C. diphtheriae?
An immunization that helped preven this infection is known as ?
False: It is
DTaP vaccine
- Infection of the middle ear is called….
2. what is the most common organism that causes it?
- Otitis media
2. S.pneumoniae (35%)
There are two other organisms that start with an S. besides S. pneumoniae that cause Otitis media. What are they?
S. pyogenes (8-10%)
S. aureus (1-2%)
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?
Haemophilus influenzae (20-30%)
reduced by vaccine
False: 3-5% of viruses cause ear infections
Are there more than one virus that helps the cause of a common cold? Name some
There are no viruses without causative agent?
rhinoviruses 50%
Coronaviruses 15-20%
other viruses 10% roughly
False: 40% of viruses have no causative agent
Common occurrence of colds with people are….
A single rhinovirus is infective for airborne transmission?
people tend to accumulate resistance
fewer colds as we get older
True
Antibiotics work excellent on viruses?
There is not much someone can do to shorten period of symptoms?
False: Anti. biotics do not work well on viruses
True
Gram - coccobacillus is what kind of organism that causes whooping cough?
It has a capsule
Has Tracheal cytotoxin of cell wall damages ciliated cells
Bordetella pertussis
toxin of whooping cough that starts with a P?
What prevents whooping cough and what is it made of?
Pertussis toxin
prevented by DTaP - acellular Pertussis cell fragments
Caused by Streptococcus pneumoniae?
It is a Gram + encapsulated diplococci
Pneumococcal Pneumonia
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
Pneumococcal Pneumonia
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
Haemophilus influenzae Pneumonia
Primary atypical pneumonia; walking pneumonia
Mycoplasma pneumoniae
Pleomorphic, wall-less bacteria
Common in children and young adults
Mycoplasmal Pneumonia
Symptoms: Mild but persistent respiratory symptoms; low fever, cough, headache
Diagnosis: PCR and serological testing
Treatment: Tetracyclines
Mycoplasmal Pneumonia
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
Legionellosis
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
Respiratory Syncytial Virus (RSV)
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
Influenza (Flu)
Hemagglutinin (HA) spikes used for attachment to host cells
Neuraminidase (NA) spikes used to release virus from cell
The Influenza Virus
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
The Influenza Virus
