100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Microbiology Exam Study Guide CA$20.15   Add to cart

Exam (elaborations)

Microbiology Exam Study Guide

 16 views  0 purchase

1. Approaches to Control Microbes a. Physical Methods i. Dry 1. incineration or dry oven  sterilization ii. Moist heat 1. Boiling water, steam under pressure  sterilization 2. Kills microbes by denaturing enzymes 3. Ex. Autoclaving iii. Radiation 1. Irradiation – bombardment wit...

[Show more]

Preview 2 out of 7  pages

  • January 27, 2021
  • 7
  • 2020/2021
  • Exam (elaborations)
  • Questions & answers
All documents for this subject (46)
avatar-seller
Welch1
Microbiology Exam 2 Study Guide

Chapter 11 – Controlling Microbes
1. Approaches to Control Microbes
a. Physical Methods
i. Dry
1. incineration or dry oven  sterilization
ii. Moist heat
1. Boiling water, steam under pressure  sterilization
2. Kills microbes by denaturing enzymes
3. Ex. Autoclaving
iii. Radiation
1. Irradiation – bombardment with radiation
2. Ionizing – can penetrate a solid barrier, bombard a cell, enter it,
and dislodge electrons form molecules
a. x-ray, cathode, gamma  sterilization
3. Nonionizing – enters a cell, strike molecules, and excites them.
Results? Mutation of DNA
a. Note: non-ionizing radiation cannot penetrate a solid
barrier
b. UV  disinfection
iv. Chemical Methods
1. Antimicrobial chemicals  disinfection or sterilization
2. Gases  disinfection of sterilization
v. Mechanical Methods
1. Filtration of air and liquids  decontamination

2. Physical Controls
a. Heat
i. Moist heat – boiling water (100oC, 30 min)
ii. Pasteurization – milk, fruit juices; flash method (~72oC, 15 sec)
iii. Pressurized steam – autoclave (121oC, 15psi); used for surgical
instruments, commercial canning (clostridium botulinum, problem in
canning)
b. Radiation
i. Gamma radiation – DNA
1. Medical equipment, drugs, food-safe
ii. Ultraviolet radiation – DNA
iii. Microwave – heat

, 3. Factors in Treatment
a. Situation – home, hospital, lab, factory
i. Sepsis – the growth of microorganisms in the blood & other tissue
b. Surface or medium
c. Type and number of microorganisms
i. Highest resistance = endospores
ii. Moderate resistance = mycobacterium, S. aureus
iii. Least resistance = non-endospore formers
d. Environment
e. Concentration of agent being used
f. Mode of action

4. Mechanical Controls
a. 2 kinds
i. Fluid filtration
ii. Air filtration – HEPA; hospitals
b. Decontaminating Congress – letters containing Bacillus anthracis were opened in
Hart Office of US Senate in 2001
i. B. anthracis is spore-forming – eradication is tough; building was heavily
populated, needed to decontaminate heating/AC vents, carpet, furniture,
office equipment, sensitive papers, artwork, personal belongings
c. Decontamination Process
i. Size/scope – samples taken from 25 buildings
ii. Decontamination – vacuum with HEPA filter followed by tx with liquid
chlorine dioxide (sterilant used for treatment of medical waste) or a
decontamination foam; heavily contaminated areas used gaseous ClO 2

5. Chemical Controls
a. Factors for choosing appropriate germicide: storage/stability, residue,
cost/availability, environmental risk
b. Germicidal Chemical:
i. Alcohols, hydrogen peroxide (H2O2), ethylene oxide (used on medical
instruments, plastics; sugar, spices)

6. –static? or –cidal?
a. Bactericide – a chemical that destroys bacteria except for those in the endospore
stage
b. Germicide/Microbicide – chemical agents that kill microorganisms
c. Bacteristatic – prevent the growth of bacteria on tissues or on objects in the
environment
d. Fungistatic – inhibit fungal growth
e. Microbistatic – antiseptics & drugs (used in the body)
f. Degermination – reducing the number of microbes on the skin (ex. hand
sanitizers)

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller Welch1. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for CA$20.15. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

76449 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
CA$20.15
  • (0)
  Add to cart