Exam 3 Review Guide Medical Microbiology – BIOL215 Fall 2024

Flashcards created to help review key concepts in Medical Microbiology for preparation for Exam 3.

What is a D Value in microbial control?

The D Value is the time required to kill 90% of the organisms in a specific population at a given temperature.

List the four agents for control of microbes.

1. Inexpensive, 2. Fast-acting, 3. Stable during storage, 4. Harmless to humans, animals, and objects.

What are the four Biosafety Levels (BSL)?

BSL-1: Handling pathogens that do not cause disease in healthy humans. BSL-2: Handling moderately hazardous agents. BSL-3: Handling microbes in safety cabinets. BSL-4: Handling microbes that cause severe or fatal disease.

What is thermal death point?

The lowest temperature that kills all cells in broth in 10 minutes.

What is the purpose of autoclaving?

To sterilize equipment by using moist heat at 121°C and 15 psi for 15 minutes.

What is the effect of refrigeration on microbial growth?

Refrigeration decreases microbial metabolism, growth, and reproduction.

How do high concentrations of salt or sugar inhibit growth?

Cells in hypertonic solutions lose water, which can inhibit microbial growth.

What are the two types of radiation used for microbial control?

Ionizing radiation (shorter than 1 nm wavelengths) and non-ionizing radiation (greater than 1 nm wavelengths).

What is the role of phenolic compounds?

They denature proteins and disrupt cell membranes, effective even in the presence of organic matter.

What is the function of alcohols in microbial control?

Intermediate-level disinfectants that denature proteins and disrupt cytoplasmic membranes.

What similarities exist between B Cell Receptors (BCR) and T Cell Receptors (TCR)?

Both have V(D)J recombination, generate an antigen-binding site, and undergo somatic hypermutation.

What is the role of the immune system’s innate arm?

It acts immediately upon infection, providing a non-specific response to a wide range of pathogens.

What are the classes of antibodies?

IgA, IgD, IgE, IgG, and IgM.

What does the term 'pathogenicity' refer to?

The ability of a microorganism to cause disease.

How can normal microbiota become opportunistic pathogens?

When normal microbiota are introduced into unusual sites in the body, during immune suppression, or due to changes in the normal microbiota.

What is the difference between incidence and prevalence in disease tracking?

Incidence is the number of new cases during a specific time period, while prevalence is the total number of cases at a given time.

What are the primary and secondary lymphoid organs?

Primary: Red bone marrow and thymus. Secondary: Lymph nodes, spleen, tonsils, and mucosa-associated lymphoid tissue (MALT).

What is the function of the complement system?

A cascade of proteins that enhances the immune response through opsonization and pathogen lysis.