COURSE
SCIE1046: Fundamentals Of Microbiology With Lab
1. About the Lab
Learning Objectives:
- Distinguish vertical gene transfer from horizontal gene transfer.
- Understand the concept of genetic variability and survivability in bacteria.
- Describe the concept of horizontal gene transfer.
- Identify genetic elements and cell machinery required for DNA transfer.
- Outline the main events that occur during conjugation, transformation, and transduction.
- Discuss the outcome and barrier of genetic transfer in bacteria.
Estimated Length: 35 to 40 minutes
MAKE THE CONNECTION
The background information in section 2 was adapted from the following Microbiology lecture course Tutorials:
3.4.4 Asexual Reproduction and Genetic Diversity
5.1.1 Classifications, Types, and Terminology of Disease
5.1.4 Virulence Factors of Bacteria and Viruses
5.2.1 An Introduction to Epidemiology
5.2.2 Disease Transmission
2. Background Information
The following background information will be helpful as you prepare for the simulation.
2a. Patterns of Incidence
Diseases can be described by their patterns of incidence. These terms help to convey the severity of the risk of spread of the disease. For example, sporadic diseases occur occasionally, usually without any particular geographic concentration. In contrast, endemic diseases are constantly present (often at a low level) in a population for a particular geographic region.
When the number of cases of diseases increases more than expected within a short time within a particular geographic region, the disease is described as an epidemic.
Epidemics generally occur because of some sort of change, such as a change in environmental conditions, in the population, or in the pathogen itself. Influenza strains change from year to year. Greater changes in the strains increase the risk that the virus can evade the immune system, and it is therefore common to see increases in cases.
In some cases, increases in numbers of cases occur on a very large or worldwide scale. When an epidemic occurs at this level, it is called a pandemic. The coronavirus disease 2019 (COVID-19) pandemic caused by the SARS-CoV-2 virus is a recent example.
TERMS TO KNOW
These glossary terms are important to know and will help you during the Activity.
Sporadic Disease
A disease that occurs occasionally, usually without any particular geographic concentration.
Endemic Disease
A disease that is constantly present (often at a low level) in a population in a particular geographic region.
Epidemic
An event in which the number of cases becomes greater than expected during a short time within a geographic region.
Pandemic
An increase in cases similar to that seen in an epidemic but over a large geographic area or worldwide.
2b. Introduction to Virulence Factors
Different pathogens produce different virulence factors, which are compounds or characteristics that contribute to their ability to cause disease. Virulence factors influence many characteristics of different diseases. For example, they affect how contagious a disease is, disease severity, and which treatment approaches will be most effective. If a virulence factor can be identified and inactivated, that may reduce the virulence of the pathogen.
Virulence factors are encoded by specific genes, and these can be identified using molecular Koch’s postulates.
TERM TO KNOW
This glossary term is important to know and will help you during the Activity.
Virulence Factor
A compound or characteristic that contributes to the ability of a pathogen to cause disease.
2c. Introduction to Asexual Reproduction and Genetic Diversity
Horizontal gene transfer (HGT) transfers genetic material between organisms that are not parent and offspring. Unlike vertical gene transfer, HGT can occur between organisms of different or even distantly related species.
There are three major mechanisms of HGT in bacteria:
- Transformation: a bacterial cell takes up naked DNA from the environment.
- Transduction: a bacteriophage transfers genes from one bacterium to another.
- Conjugation: one bacterium (the donor) extends a hollow tube (a conjugation pilusor a sex pilus) to another bacterium (the recipient) and genetic material moves through the pilus from the donor to the recipient.
TERMS TO KNOW
These glossary terms are important to know and will help you during the Activity.
Transformation
A bacterial cell takes up naked DNA from the environment.
Transduction
A bacteriophage transfers genes from one bacterium to another.
Conjugation
One bacterium (the donor) extends a hollow tube (a conjugation pilus or sex pilus) to another bacterium (the recipient), and genetic material moves through the pilus from the donor to the recipient.
Conjugation Pilus (Sex Pilus)
A hollow tube that extends from one bacterium to another so that genetic material can be transferred through it.
2d. Classifications, Types, and Terminology of Disease
You are encouraged to review the complete Microbiology lecture course Tutorial 5.1.1 Classifications, Types, and Terminology of Disease for background on this topic before you begin the simulation.
2e. Disease Transmission
You are encouraged to review the complete Microbiology lecture course Tutorial 5.2.2 Disease Transmission for background on this topic before you begin the simulation.
3. Lab Manual
Lab Manual – Genetic Transfer in Bacteria: Prevent the rise of superbugs!
This Lab Manual gives a synopsis of the lab and the theory behind it. You’re encouraged to read or download the manual before launching the lab. This information will also be available during the simulation by selecting the “Theory” tab on the virtual LabPad.
4. Launch Lab
You’re ready to begin! Review the helpful navigation tips below. Then click the “Launch Lab” button to start your lab. Be sure to answer all the questions in the simulation because they contribute to your score. Good luck, scientists!
- Exiting: To exit a lab simulation, press the ESC key on your keyboard. This key returns you to the objective screen for the simulation.
- Saving: You do not need to complete a simulation in one sitting. Labster saves your progress at predetermined checkpoints upon exit. To see your progress at any time, click on the “Mission” tab of the LabPad.
- Restarting: You are allowed an unlimited number of restarts for a simulation to improve your quiz score. Sophia and Labster will always store your best score.
- Just Browsing: You can restart a simulation to have a look around without completing it. The program will still retain your previous (and best) score.