Microbiology Weekly Review

Control of Microbial (Bacterial) Growth

Chemical Agents:  Disinfectants and Antiseptics

• Be able to compare
  • antiseptics and disinfectants
  • sterilization vs. disinfection
  • bacteriostatic vs. bacteriocidal
  • NOTE:  the terms in Table 12.1 on pg. 343 in the text.
• How is the effectiveness of antibacterial chemicals evaluated?
  • To what disinfectant are new ones compared?
• What are requirements for a good disinfectant or sanitizing agent?
• The following categories of chemical agents were discussed:
  • soaps and detergents
  • acids and alkalis
  • heavy metals
  • halogens
  • alcohols
  • phenols
  • oxidizing agents
  • alkylating agents
  • dyes
• You should know examples of each, how they work, and under what circumstances each is used.  Table 12.3 on page 352 is an excellent summary.

Physical Antimicrobial Agents: heat, refrigeration, freezing, drying, freeze-drying, radiation (UV and ionizing), filtration, osmotic pressure.

• You should know how each of these physical methods works to kill bacteria and other microbes.
• Which are methods of sterilization?
• Under what circumstances are each used?
• Which are used to control microbial growth in food?  Are some used in combination with chemical methods of control?
• The summary table (table 12.5) on page 361 is excellent.

Antimicrobial Therapy (Chemotherapeutic Agents)

• What is antimicrobial chemotherapy?
• Name the properties of antimicrobial chemicals and how these properties are used to control disease.
• Know the 5 modes of action of antimicrobial agents and how they are selective.
• Be able to list the characteristics of an ideal antibiotic.
• What are three kinds of side effects to chemotherapeutic agents?  Be able to give examples of each.

Infection and Disease

What is the normal flora?

• You should know what the normal flora, examples of the normal flora and the roll that it plays in the protection of the the body against infectious diseases.
• Know which parts of the body are colonized by microbes and which are microbe-free under normal conditions.
• Refer to Lab Exercise information of the normal flora of the GI and Urinary tract.
  • What are the growth conditions in the GI tract?
  • How does that affect microbial growth there?
  • What kinds of microbes comprise the normal flora of the GI tract?
  • What are some things that can go wrong?
  • How do urinary tract infections occur?
    • What kinds of microbes cause them?
    • How would you grow and identify them?

Microbes and Disease Processes

• Strategies for Colonization of Host Tissue
  • Know the pros and cons of a microbe colonizing host tissue and living within host cells (intracellularly) or outside of host cells (extracellularly).
• Be able to compare terms such as colonization, infection, and disease.
• Understand what a pathogen must accomplish to cause a disease.
  • What are the 6 requirements?  Can you name examples of each stage in the process?
    • Can you do that for a disease we studied like E. coli gastroenteritis, or Smallpox, for example.
• Microbes cause disease by interfering with normal bodily functions.  They usually do so by destroying host tissues.
  • You should be able to name the ways that bacteria destroy host tissues and give examples.
    • How do they attach and then invade host tissue?
• Be able to compare and contrast exotoxins and endotoxins in their chemical composition as well as their toxic effects and the types of bacteria that produce them.
• Know the types of infections diseases.
• Know the stages of an infection with an infectious disease.

Online Lecture:

Epidemiology

• You should be able to explain what epidemiologists do.
• Know the terms that pertain to epidemics —
  • Rates of Occurrence, Death, and Infection
  • Types of Outbreaks (epidemic, endemic, sporatic, pandemic)
    • Be able to identify these by their illustrations in the text.
  • Methods of analysis of epidemics.
• Identify the three types of reservoirs of infectious diseases and give specific examples of diseases associated with each.
• Be able to name portals of entry and exit of infectious diseases and give examples of each.
  • Specifically know diseases that may be transmitted to the fetus from the mother.
• Know the three ways that diseases may be transmitted.
  • Understand the different types of each.
  • Be able to give or identify specific examples of each.
• Know the 4 general ways that epidemics can be controlled and examples of each.
• If we know all this about infectious diseases, why do people still get sick and die?
  • Part of the answer is in the occurrence of new (emergent) and reoccurring (resurgent) diseases.
  • Know what factors contribute to emergent (and resurgent) diseases.
    • Be able to give specific examples.

Nosocomial Infections

• Why do people who are in the hospital get sick from being in the hospital?
  • What factors cause nosocomial infections?
  • What kinds of infections are most commonly nosocomial?
  • What microbes most often cause nosocomial infections?

Bacterial Growth

By what process to bacteria grow?

• Know the phases of growth as exhibited in a closed container.
• What contributes to each phase?
• How do we use this knowledge to control microbial growth

What are several methods that are used to measure the growth of bacteria?

• Which of these have we used in lab?

We discussed several physical factors that affect the growth of bacteria:

• pH
• temperature
  • Know the terms for bacteria that have different temperature optima.
  • Relate temperature requirements for growth of bacteria and foodborne infections and intoxications.
• oxygen
  • Distinguish between obligate and facultative anaerobes and aerobic bacteria.
  • Know the toxic forms of oxygen and what mechanisms are used to combat them.
  • Understand how peroxide is used as an antiseptic.
  • How are bacterial oxygen requirements related to food safety?
• moisture
  • How is this used to control bacterial growth?  or to preserve bacteria?
• osmotic pressure
  • What is osmotic pressure and how is it used to control bacterial growth?
• nutritional requirements
  • Review the elements that are essential for bacterial growth and the kinds of compounds that they are necessary for.
  • Review nitrogen fixation:  which organisms are capable of it and why it is important.

Viruses

Basic Viral Structure and Replication

• Know the structure of bacteriophages as well as animal viruses.
• Be able to identify and explain the steps in viral replication.
• Know the difference between lysogenic and lytic viral cycles.

Bacteriophages vs. Animal Viruses

• Be able to compare and contrast the infective cycles of bacteriophages and animal viruses.
• Be able to explain the steps of the infective cycle of an animal virus; use HIV as a specific example.

Effects of Infection by a Virus

• Be able to explain the possible outcomes of infection by a virus:
  • Disease process (as exemplified by influenza, herpes, smallpox, or rabies).
  • Teratogenesis
  • Cancer
• Be able to discuss in detail the influenza virus:
  • Its structure and the role of this structure in infection as well as genetic drift and shift.
  • Why the 1918 influenza pandemic was so devastating;
  • What its reservoir is and how it goes from infecting birds to infecting humans;
  • What steps are taken to prevent a pandemic like the 1918 one;
  • The dangers of avian flu.
• How can viral infection lead to secondary bacterial infections?

Viral Diseases –Lectures are online in Vancko Hall

• Small Pox, Influenza, Rabies, Herpes
• Also Avian Influenza!

Viral Structure

• Know the basic structure of viruses including naked and enveloped viruses.  Note the relative sizes and the shapes of viruses as illustrated in Figure 10.2 pg. 274 in your text.
  • Terms include:
  • capsid
  • capsomere
  • nucleic acid
  • spikes
  • virion
  • nucleocapsid

Viral “Activity” as Obligate Intracellular Parasites

Know the ideas about the origin of viruses as outlined in your text.

• In what ways are they living?  …nonliving?

Reading:

• Be sure to read the introduction to viruses in your text (pp.271-276)
• Read up on Herpesviruses in your text:  pp. 627-632
• Read about influenza in your text pp. 660-665.
• ALSO be sure to read the article in Vancko Hall on Influenza!
• Here is the link to the CDC information on H1N1 for you.

From your reading you should have an understanding of influenza infection as well as

• the structure of the influenza virus and the significance of the different  “H#N# combinations.
• the importance and meaning of genetic drift and genetic shift in terms of influenza.
• the significance of the 1918 influenza epidemic and its possible relationship to the current H1N1 influenza virus pandemic.

Kinds of Bacteria (Prokaryotes) and How We See and Identify Them

• Show and understanding of the Three-Domain System of classification and be able to contrast it with the Five Kingdom System we covered earlier in the semester.
  • Which system do you think best describes living organisms and their evolutionary relationships?  Justify your answer.
• Know the differences between the Eukbacteria and the Archaebacteria
  • Why are the Archaebacteria called extremophiles?
• In the Eubacteria know about some specialized bacteria such as:
  • Chlamydias and Rickettsias and how they differ from bacteria such as E. coli and Staphylococcus.
  • Know the diseases caused by Chlamydia and especially the impact of Chlamydia that causes blindness.
• Be able to distinguish among light, transmission electron and scanning electron micrographs.
  • What are the advantages and disadvantages of the use of these three kinds of microscopes?
• Know why we stain bacteria cells and which stain and microscope techniques are useful in different situations and for different kinds of bacteria and eukaryotes.
• Know the differences between selective and differential agar as well as some examples of each that we have used in lab.

The Origin of Eukaryotes from Prokaryotes

• Be able to describe the process by which eukaryotes arose from prokaryotic cells.  [In other words explain the Endosymbiotic Theory of the Origin of Eukaryotes.]

• Be able to give examples of the evidence that exists for this theory using mitochondria and chloroplasts.
  • What eukaryotic organelle is NOT thought to have originated this way?

Looking Ahead to Week 7:

Biological Warfare:  Anthrax as an Example

• Know the characteristics of an ideal biological weapon.
• Be able to explain how bacterial structure of B. anthracis lends it self to use as a biological weapon.
• Be able to discuss the problems in developing/using a biological weapon.
  
  • What structures that are typical of some prokaryotic cells, make Anthrax such a prime candidate for use as  a biological weapon?
  • Note that after we have covered viruses you will be asked to compare and contrast smallpox and anthrax for use as biological weapons.

Prokaryotic Cell Structure

• Be able to describe the structure of a prokaryotic cell as well as the functions of the structures.  Especially pay attention to the contrast in structure and function of prokaryotes vs. eukaryotes.
• Be able to show that you understand the ways that  microbiologists use the differences between these basic cell types to their advantage.
• Be able to show that you understand the relationship between endotoxins and gram negative cell wall structure.
  • Know what exotoxins are, what kinds of bacteria produce them as well as some examples.
  • Why can exotoxins be inactivated and used as vaccines while enodoxoins cannot be used in this way?  What diseases are prevented by vaccination with toxoids?  What is an antitoxin?
• Know the nature and function of endospores.
  
  • What diseases are caused by endospore-forming bacteria?
  • If one bacterium in your unknown mixture produces spores, what shape and gram reaction would it most likely have?
• Show an understanding of the variety of structures within the Prokaryotae, for example, the variety in cell walls.
  • You should be able to answer questions related to laboratory and the gram stain — this includes the reagents that are used as well as why Gram positive cells are purple and Gram negative cells are pink.

• Be able to compare and contrast Eukaryotic and Prokaryotic Cell Structure.  There is a table in Vancko Hall in this unit that you can use as a template to fill in this comparison.

I have also posted the NY Times article about pets and bacteria that can infect humans entitled “Tie to Pets has Germs Jumping To and Fro.  It is in Vancko Hall Lecture  in this unit.

Microbiology and the Progress of Science

• Be able to show an understanding of how science progresses by listing the major discoveries that lead to the understanding of what microbes could do (including cause disease).
  • What was the result of the understanding that microbes caused disease?
  • When were there first cures for infectious diseases?
• Be able to describe process that scientists go through to make scientific discoveries.
  • Be able to describe the steps in the scientific method using either Pasteur’s confirmation that biogenesis was true OR the use of Koch’s postulates.
  • Using Redi’s experiments with meat and maggots describe the scientific method.
    
  • Using Redi’s experiments with meat an maggots to explain the importance of Pasteur’s later work with crook-necked flasks.

Eukaryotic Cell Structure

• Know the structure and function of organelles typical of eukaryotic cells
• Compare and contrast the structure and function of mitochondria and chloroplasts.
• Know the structure and role of cell membranes.
• Know and be able to describe the steps in the process of phagocytosis (see the diagram of phagocytosis)

Exam 1 Will be Tuesday September 29th

It will consist of 35 multiple choice and matching questions that will be scantron graded so bring a #2 pencil to fill in the answer sheet.  This portion is worth 70 points.  For 30 points you will be asked to answer 3 (out of several) essay questions.  You will have 1 hour and 15 minutes to complete the exam.

It will cover everything we have gone over in lecture so far this semester.  Remember that lab overlaps lecture in this portion of the course!

Potential Essays:

1. Explain Koch’s postulates. Why are they important?

2. Explain how Pasteur was able to prove biogenesis.

3. Show and explain the steps in the Scientific Method using Pasteur’s proof of biogenesis. [The answer to this questions includes a list of the steps in the Scientific Method and THEN how Pasteur's experiments fit into those steps.]

4. Explain why infectious diseases are important in the world today. What measures can be taken to lower the deaths from infectious diseases in the world.

5. Compare and contrast the following pairs of terms. OR Tell what each of the items is and how it is related to the other item. [If it isn't related in any way, say so.]

• Algae and Protozoa (e.g. Volvox and Paramecium )
• Algae and Cyanobacteria (Spirogyra and Oscillatoria )
• Eukaryote and prokaryote
• Ectoparasite and endoparasite
• Infection and Intoxication
• Trophozoite and cyst
• Apical complex and cyst
• Sporozoite and merozoite
• Cestode and Nematode and Trematode

6. Draw a simple diagram of the life cycle of the malarial parasite and label it. OR Label the drawing and explain the life cycle of the malarial parasite.

7. Should organisms like Euglena (which has chloroplasts, a flagellum, but can be heterotrophic, be place in with the Algae or the Protozoa? Why or Why not?

8. Where do you think organisms like Oscillatoria should be placed, in the Cyanobacteria or the Algae? Explain your reasoning.

9. Explain the factors that have contributed with the difficulties in controlling malaria.

10. Label and explain the diagram of phagocytosis.

11. Explain the ways that humans can become ill from fungal (or protozoan) diseases; give examples.

12. Discuss two important diseases caused by trypanosomes.

13. Compare and contrast the structure and function of chloroplasts and mitochondria.

14. Explain the structure of DNA and how it controls what goes on in the cell.

Protozoan Diseases

• Be able to discuss the major ways that protozoa cause disease and any structural adaptations they may have for this.
• Be able to label and explain a diagram of the life cycle of the malaria parasite.
• Be able to discuss the reasons why malaria has been so difficult to eliminate world-wide.

The Fungi (Kingdom Myceteae)

• Know the characteristics of the fungi.
• Be able to explain and give examples of their inability to compete with bacteria
  • and how this can be medically important.
• Know the way that fungi are classified and the classification of fungi with examples.
• Know the types of asexual and sexual spores produced by the fungi.
• Be able to list the ways that fungi cause disease and give examples.
  • Know about fungal intoxications:  aflatoxicosis, ergotism, and mushroom intoxication.
  • Fungal infections:  histoplasmosis, and candidiasis.

Quiz 1 — On-line

Quiz 1 is online:

• Worth 33 points.
• There are 22 questions — two are  matching questions that have 5 or 6 matches.
• Once you log on and start the quiz you have 45 minutes to complete it.
• It must be completed by 11:55 PM EDT Wednesday September 23rd.
• It covers:
  • Kingdoms
  • Importance of Infectious Diseases World-Wide
  • The Kingdoms Protista and Myceteae
  • Diseases that are characteristic of those kingdoms.
  • Chemistry — especially the 4 groups of organic compounds (carbohydrates, etc.)

Spring ‘09 Questions

Characteristics of the Kingdoms and Introduction to the Kingdom Protista

Word cloud created from this week's terms using wordle.net

The Kingdoms:

Be able to distinguish among the 5 kingdoms of living organisms and the viruses and prions.

• Know the basic characteristics of each of these 7 groups and the kinds of organisms or entities that are included in each.
• Be able to explain the Five Kingdom System of classification and how it is depicted.

Kingdom Protista — Protozoa and Algae

• Know the characteristics that apply to all members of this kingdom.

Protozoa:

• Be sure to review the basics of Parasitology and its associated terms.
• Know the characteristics of the Protozoa.
  • In general be able to describe how protozoans cause disease.  [Later we cover specific diseases.]
• Know the characteristics of the Phyla of Protozoa and how they are distinguished from one another.
• Know examples of those that cause disease.

Algae:

• Show an understanding of algal structure and function.
  • Be able to show how algae are important to humans.
  • Know about PSP and Ciguatera
• Be able to compare and contrast Protozoa and Algae
• Know why Cyanobacteria are bacteria and not algae.

The lecture on this kingdom is available online.  There are also sample exercises (some of which come from previous exams) for you to try that will give you an idea of the kinds of questions I ask on exams.  All of these are available on Vancko Hall.

This week (Week 2) I’ll be finishing up Protista, talking about malaria and other diseases caused by protozoans.  Then I’ll lecture on a bit of History and introduce the fungi because you’ll be looking at them in lab on Week 3.

Welcome to General Microbiology at SUNY Delhi

What is this?

• Well this is a blog to help you in the course.  I will post weekly to this blog with review material.
• Each weekend I update the blog by reviewing the material that we’ve covered during the week in lecture.
  • I have another blog that is a preview or briefing for each week’s lab.
  • The lab briefing blog is posted by the end of one week and gives you a preview of the next week’s lab.
  • I expect that you will print out that briefing and bring it to lab with you.
• This is a review blog.  It will contain such things as
  • an outline or review sheet of important things we’ve gone over.
  • sample multiple choice and matching questions (some of these will be in Vancko Hall as “Hot Potatoes Quizzes” which are just practice quizzes.
  • sample essay questions for exams.

Why a blog?  Why not just post a review in Vancko Hall?

• Primarily because I can (and have) add a RSS feed for you.
  • What does that mean?  Well it means that you can subscribe to this blog.  So that every time I update it or make a new posting, you get a message that tells you that I’ve updated it.  You can also add the RSS feed to your feed burner if you want.  [A feed burner is a program that holds your subscriptions.  Google Reader, for example, is a feed burner.]
• Also you can send it comments or questions easily.
• AND it puts all of the review material in one readily accessible place.
• I suggest that you bookmark the blog.  That way if the Delhi system goes down you can get to the blog at least!

So… Welcome!  Use the blog and the other resources I provide for you and you’ll do fine in the course!

Dr. Stock