Download Reading Guide for Week 1 – Bio260

Reading Guide for Week 1 – Bio260, Fall 2013
Colleen Sheridan
Stage 01 – Disease Transmission
In this unit we are trying to figure out how diseases like whooping cough, influenza, and healthcare-associated
infections (HAIs) are transmitted and how their transmission through the environment can be reduced.
In this week’s reading you will learn about:
1. Diversity and naming of microbes
2. Mechanisms of disease transmission and public health agencies who work to reduce it
3. Prokaryotic cellular structure, so we can understand how to identify bacteria and how their structures
give them function. This is important for understanding how bacteria cause disease, how to treat
their infection, and how to control their presence and growth in the environment to reduce
transmission of disease.
Chapter 1: Microbial World
So far from our reading in Week 1, we’ve learned about
the diversity of microbes in the world (living cellular microbes like bacteria, archaea, and some eucarya
such as algae, protozoa, fungi; and non-living microbes like viruses, viroids, and prions),
how bacteria are named through the Binomial System of Nomenclature (Genus species: Escherichia
coli, Staphylococcus aureus, Bordetella pertussis, etc…),
how tiny microbes are (eukaryotic cells: 10-100 µm; bacteria: 1-10 µm; viruses: 50-100 nm)
Chapter 19: Epidemiology
And we built on that foundation to try to understand how vaccine-preventable diseases like whooping cough
(pertussis), influenza, measles, and HAIs like Clostridium difficile, Staphylococcus aureus, and members of the
family Enterobacteriaceae are transmitted. We learned about
how to describe the rate of disease in a population using the words endemic, epidemic, pandemic, and
outbreak
the reservoirs of infection, or the natural habitat of a microbe, and that people carrying the microbe can
have symptomatic infections or be asymptomatic carriers.
The portals of entry and exit into and out of the organism in order for the microbe to spread to a
susceptible new host such as fecal-oral transmission, respiratory transmission, and sexual
transmission
the mechanisms of disease transmission like contact transmission (direct contact, indirect contact
through fomites, and droplet transmission), and transmission through food, water, air, and
vectors.
How public health organizations like the CDC, the WHO, the Washington State Department of Health,
and Seattle & King County Public Health work to control and prevent the spread of infectious
disease.
How HAIs are one of the top ten causes of death in the US, what different types of infections there are,
their common causes, the reservoirs of infection in healthcare (patients, environment, personnel),
the major mechanisms of disease transmission in healthcare settings (medical devices as fomites,
direct transmission from healthcare personnel, and airborne transmission), and hospital Infection
Control Committees and the CDC’s Healthcare Infection Control Practices Advisory Committee
(HICPAC) that work to control and prevent the transmission of infectious disease.
How Standard Precautions can help protect patients and personnel from infectious disease transmission
by recommending things such as hand-washing and care of the environment through cleaning
and disinfection.
Now we need to know how to reduce the transmission of disease in our environment (microbial control) as well
as how to identify the microbe that might be causing a disease! To understand how disinfectants and antiseptics
work and how microbes grow and cause disease, we need to know about their cellular structures and how they
function. To do this we read about prokaryotic cell structure in Chapter 3. Here are some study questions to
help you get the most from this chapter:
Chapter 2: The Molecules of Life (You will not have to read this chapter if you already have basic knowledge
of biochemistry. So skim through it to make sure you refresh your memory of these concepts. They will come
in handy as we try to understand how to reduce disease transmission.)
Chapter 3: Microscopy and Staining
1. What is a smear ? Why do you heat fix a smear?
2. Describe the principle of simple staining. What can you determine about an organism from a simple stain?
3. What is a differential stain? Give an example of a differential stain.
4. Describe the four steps of the Gram stain and the purpose of each step. What physical
characteristic
does it differentiate? What color are Gram + and Gram - cells?
5. Describe the following staining techniques and their uses: acid-fast staining, negative staining, and
endospore staining.
6. Know the parts of a bright-field compound microscope and their function.
7. Understand the function of the following types of microscopes: phase-contrast, dark-field,
fluorescence, transmission electron, and scanning electron. Be able to give an example of when you would
use each kind of microscope.
8. Understand the differences between a prokaryotic cell and a eukaryotic cell.
9. Know the various shapes of bacteria and the typical cell groupings.
10. Describe the following cell structures and their function: glycocalyx (differentiate between a
capsule and a slime layer), flagella, pili, fimbriae, cell wall (know the complete composition),
cytoplasmic membrane, chromosome, plasmid, periplasm, cytoplasm, nucleoid, ribosomes, storage
granule, endospore.
Be able to provide an example of an organism that contains a structure above using the genus and
species name.
11. Know the structures of Gram-positive and Gram-negative cell walls.
12. Understand how lysozyme effects peptidoglycan.
13 Understand how penicillin effects peptidoglycan.
14. What is the function of endospores? How are they made?What are the steps in the synthesis of a spore?
Name a bacterial genus that produces endospores.
15. Understand the different ways to transport material across a cytoplasmic membrane. Understand the
different ways bacteria move material across a membrane such as facilitated diffusion and active transport
mechanisms (transport systems that use proton motive force, transport systems that use ATP, and efflux
pumps).
16. What are the functions of the bacterial cytoplasmic membrane?