Substances that are naturally produced by certain microorganisms that can inhibit or destroy other microorganisms are called
Important characteristics of antimicrobial drugs include
-low toxicity for humans
-stable & soluble in body tissues and fluids
-do not cause serious side effects in humans
-high toxicity against microbial cells
Microbial resistance resulting from mutation occurs because
-prokaryotic genomes undergo mutation often and rapidly
-short generation times accumulate mutations in populations
-mutations are passed between organisms
A ratio of the dose of the drug that is toxic to humans vs the minimum effective dose for that pathogen is assessed to predict the potential for toxic drug reactions. This is called the
Therapeutic index (TI)
The cellular basis for bacterial resistance to antimicrobials include
-synthesis of enzymes that alter drug structure
-alteration of drug receptors on cell targets
-prevention of drug entry into the cell
-bacterial chromosomal mutations
A clinical microbiologist makes serial dilutions of several antimicrobials in broth, and then incubates each drug dilution series with a standard amount of a patient's isolated pathogen. What is this microbiologist setting up?
Minimum inhibitory concentration (MIC)
All of the following result in drug resistance
-drug blocked from entering the cell
-drug pumped out of the cell
-drug binding site altered
Each of the following is a mechanism for drug resistance transfer between microorganisms except
The multidrug resistant pumps in many bacterial cell membranes function by
removing the drug from the cell when it enters
If pathogen A is more resistant to an erythromycin disc on a Kirby-Bauer plate compared to pathogen B, then pathogen A will have a(n) _____ zone of inhibition compared to pathogen B.
The human body typically begins to be colonized by its normal biota
during and immediately after birth
Normal biota includes each of the following except
All are correct: bacteria, fungi, protozoans, viruses
Once a microbe has entered a host, what process performed by certain white blood cells will attempt to destroy the microbes?
Microbial hyaluronidase, coagulase and streptokinase are examples of
Exotoxins?? Should be exoenzymes I believe pg 373
_____ are toxins that are the lipopolysaccharide of the outer membrane of gram negative cell walls.
A _____ is an infection indigenous to animals that can, on occasion, be transmitted to humans.
______ carriers are shedding and transmitting pathogen a long time after they have recovered from an infectious disease.
When would Koch's Postulates be utilized?
Determination of the cause of a new disease in a microbiology research lab
The principal government agency responsible for tracking infectious diseases in the United States is
Centers for Disease Control and Prevention
The number of new cases of a disease in a population over a specific period of time compared with the healthy population is the ?
Nonspecific chemical defenses include
-Lactic acid and electrolytes of sweat
-Skin's acidic pH and fatty acids
-Stomach hydrochloric acid
The chemical found in tears and saliva that hydrolyzes the peptidoglycan in certain bacterial cell walls is
The body region where a ciliary escalator helps to sweep microbes trapped in mucus away from that body site is the
The reticuloendothelial system
-Is a support network of connective tissue fibers
-Originates in the cellular basal lamina
-Provides a passageway within and between tissues and organs
-Is heavily populated with macrophages
What structures are found along lymphatic vessels and are heavily clustered in the armpit, groin and neck?
Which gland shrinks in size during adulthood and has hormones that function in maturation of T-lymphocytes?
The molecular fragment on an antigen molecule that a lymphocyte recognizes and responds to is called a/an
Which process involves antibodies covering surface receptors on a virus or toxin molecule thereby disrupting their activity?
Which process involves antibodies cross-linking cells or particles into large aggregates?
Which process involves antibodies coating microorganisms in order to facilitate phagocytosis?
What process provides many B cells and T cells that are activated against specific antigens?
Which lymphocytes lack specificity for antigen and are cells that attack cancer cells and virus-infected cells?
Natural killer cells (NK)
The beauty of specific immunity is the production of ____ that provides long-lasting protection
The embryonic yolk sac, the liver and the bone marrow are sites where
Stem cells give rise to immature lymphocytes
Cell surface markers involved in immune reactions
-Are the result of genetic expression
-Function in recognition of self molecules
-Receive and transmit chemical messages among other cells of the system
-Aid in cellular development
-Possess MHC antigens for recognizing self
-Have membrane receptors that recognize foreign antigens
-Gain tolerance to self by destruction of lymphocytes that could react against self
-Develop into clones of B and T cells with extreme variations of specificity
Properties of effective antigens include all the following EXCEPT
Large polymers made up of repeating subunits
Properties of effective antigens include all the following
-Foreign to the immune system
-Large molecules with a minimum molecular weight of 1,000
-Cells or large, complex molecules
Antigen presenting cells
-Include dendritic cells
-Engulf and modify antigen to be more immunogenic
-Hold and present processed antigen on their cell membrane surface
The science called _________ studies interactions between microbes and their environment and how those interactions affect the earth.
A collection of organisms together with their physical and chemical factors are called a/an
Organisms that inhabit soil or water and breakdown and absorb the organic matter of dead organisms are called
Which of the following are primary photosynthesizers?
-Green sulfur bacteria
-Purple sulfur bacteria
-Purple nonsulfur bacteria
- Encourages heavy surface algal blooms
-Causes massive die-off of fish and invertebrates
-Can block the O2 supply to the lake
-Occurs when there are excess nutrients in aquatic ecosystems