Aeromicrobiology - Chapter 5

Question 1

For you to decide, do we need to be concerned about aeromicrobiology?

Answer 1

yes, but be mindful to what pathogen are present and if they are level 2 or level 3

Question 2

Be able to describe the launching, transport, and deposition of the aeromicrobiological pathway

Answer 2

• size matter, smaller allows for longer suspension in air and for further travel in air way
• Launching: direct (sneeze) vs. indirect (breeze, dust)
• Trasnprt : instantaneous vs. survival
• distance vs. survival
• deposition : gravity and weather

Question 3

Explain why there are typical distances that microbes travel, how these are measured, and examples of exceptions to these

Answer 3

• size :smaller will go further , can spend more time in air
• based on particle size
• 16S rRNA ID species

Question 4

List factors that impact microbial survival in bioaerosols

Answer 4

• temp
• light
• moisture
• particle size
• spore formation or not
• nutrients presense

Question 5

Explain how bioaerosols can be controlled (or can they)?

Answer 5

• filtered out of air

- UV light exposure

Question 6

Be able to discuss and give examples of microorganisms of concern in disease, biological warfare, closed environments, and extraterrestrial environments that may be spread through aerosols

Answer 6

• if microorganism are level 3 or even level 2 we have to worry about exposure
• Pulmonary Tuberculois (Mycobacterium tuberculosis) or Pulmonary anthrax (Bacillus anthracis)
• Aspergillosis (Aspergillus fumigatus)
• Influenza (Influenza virus) or Chicken pox (Herpesvirus)

Question 7

Describe the biosafety levels used in research and medicine

Answer 7

• level 2: ingested/ looking to diminish exposure to external env.
• level 3 : inhaled / must be air tight, enter via differentiated air pressure system
• route of infection is key *

Question 8

what do you think is the largest source of microbes in the air?

Answer 8

it depends on your location and what is in your area.

Question 9

What are some examples of mesocale and macroscale transport

Answer 9

• aphthovirus: can persist in damp soil for over a month ( cold temps help)
• -> hoof and mouth diseases (mesoscale)

Question 10

Downward molecular diffusion

Answer 10

Natural air currents and eddies enhance the downward movement of particles and increase the rate of deposition

Question 11

surface impaction

Answer 11

Airborne particles can collide with numerous objects including other small particles, trees, buildings, etc. After a collision, the particle can stick or bounce off.

Question 12

What does microbial survival in aerosols depend on ?

Answer 12

1. Type of microorganism (spore forming bac, molds, fungi)
2. relative humidity
3. temperature
4. radiation (UV light)

Question 13

Enveloped nuclear capsid

Answer 13

when virus uses part of host cells membrane when they lyse

Question 14

why is the airborn route of infection such a concern ?

Answer 14

difficult to control spread(wind)

- must use fungicide for Wheat rust

Question 15

What my affect the ability of an airborne microbial infection to occur?

Answer 15

the size, humidity, radiation and the organism

-presence of factors like prevailing winds

Question 16

Discuss LPS

Answer 16

• lipopolysasscharide is an endotoxin released from Gram + bac
• 10ng can cause toxic effect
• can come from variety of industrial (Sewage treatment plants) and natural sources (haystacks)

Question 17

Coccidioides immitis

Answer 17

• C.immitis = valley fever, level 3 pathogen
• 30-40% of poeple have antibodies
• 60% have been infected in the US
• Infectious but not contagious ( dead end host)
• treat with amphotericin B

Question 18

Intramural microbiology

Answer 18

• limmited circulation of external air
• much less UV exposure
• relative humidity supportive of growth
• temperature supportive of growth
  ie. . office buidlings, hispitals, labs, spacecrafts

Question 19

Tuberculosis info

Answer 19

• tb, one third of the population is infected.
• In 1999 TB caused 8,000 deaths/day

-7- 8 million people become infected with TB/year

-TB accounts for more than 1/4 of all preventable adult deaths in the developing world.
Someone is newly infected with TB every second !

• TB is the leading killer of women in low income countries (1/3 leading cause of death in women worldwide) (TB in women)
• TB is the leading cause of death among HIV-positive individuals
• TB evolves along with humans
• TB is on the decline (WHO report 2011) (8.7 million new cases compared to 8.8 million new cases in 2010)