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105 terms

Micro final

Micro 275 final (2nd half of class)
STUDY
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Substances that are naturally produced by certain microorganisms that can inhibit or destroy other microorganisms are called
Antibiotics
Antibiotics are derived from all of the following except
Staphyloccous
Antibiotics ARE derived from
Bacillus, Cephalosporium, Streptomyces, Penicillium
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
Selective toxicity refers to
damage to the target organism but not vertebrate 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)
Ampicillin, amoxicillin, mezlocillin and penicillin G all have
a beta-lactam ring
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)
Each of the following result in drug resistance except
drug used as a nutrient by the cell
All of the following result in drug resistance
-drug blocked from entering the cell
-drug inactivated
-drug pumped out of the cell
-drug binding site altered
Each of the following is a mechanism for drug resistance transfer between microorganisms except
mutation
Mechanisms for drug resistance transfer
-transposons
-conjugation
-R-plasmids
Which TI value would be the drug of choice?
20
The multidrug resistant pumps in many bacterial cell membranes function by
removing the drug from the cell when it enters
Drug susceptibility testing
determines the pathogen's response to various antimicrobials
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.
Smaller
Infection occurs when
pathogens enter and multiply in body tissues
The human body typically begins to be colonized by its normal biota
during and immediately after birth
Resident biota are found on the
skin, mouth, nasal passages, large intestine
Normal biota includes each of the following except
All are correct: bacteria, fungi, protozoans, viruses
The effect of "good" microbes against invading microbes is called
microbial antagonism
Opportunistic pathogens
cause disease in compromised individuals
Pathogenic microbes that cause disease in health people are called
true pathogens
The minimum amount of microbes in the inoculating dose is the
infectious dose
Which of the follow in not a method of adhesion?
Cilia
Once a microbe has entered a host, what process performed by certain white blood cells will attempt to destroy the microbes?
Phagocytosis
Virulence factors include all the following except
Ribosomes
Virulence factors include
Capsules, exoenzymes, endotoxins, exotoxins
Microbial hyaluronidase, coagulase and streptokinase are examples of
Exotoxins?? Should be exoenzymes I believe pg 373
Exotoxins are?
proteins
Exotoxins
are secreted by pathogenic organisms
An endotoxin is
indicative of Gram negative organisms
_____ are toxins that are the lipopolysaccharide of the outer membrane of gram negative cell walls.
Endotoxins
The subjective evidence of disease sensed by the patient is termed a/an
Symptom
The objective, measurable evidence of disease evaluated by an observer is termed a/an
Sign
Infections that go unnoticed because there are no symptoms are called
asymptomatic
The primary, natural habitat of a pathogen where it continues to exist is called the
reservoir
Someone who inconspicuously harbors a pathogen and spreads it to others is a
carrier
A _____ is an infection indigenous to animals that can, on occasion, be transmitted to humans.
zoonosis
______ carriers are shedding and transmitting pathogen a long time after they have recovered from an infectious disease.
chronic
An inanimate object that harbors and transmits a pathogen is a
fomite
Which of the following is transmission of disease from mother to fetus?
vertical
When would Koch's Postulates be utilized?
Determination of the cause of a new disease in a microbiology research lab
The study of the frequency and distribution of a disease in a defined population is
Epidemiology
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 ?
Incidence rate
The total number of deaths in a population due to a disease is the _____ rate.
Mortality
Nonspecific chemical defenses include
-Lysozyme
-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
Lysozyme
The body region where a ciliary escalator helps to sweep microbes trapped in mucus away from that body site is the
Skin
Respiratory tract
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
Immune system cells differentiate between self and foreign cells by their
Markers
The most numerous WBC's, that have multi-lobed nuclei and are very phagocytic are
Neutrophils
Hematopoiesis is the
Production of white blood cells, red blood cells and platelets
What structures are found along lymphatic vessels and are heavily clustered in the armpit, groin and neck?
Lymph nodes
Which gland shrinks in size during adulthood and has hormones that function in maturation of T-lymphocytes?
Thymus
Diapedesis is the
Migration of white blood cells from the blood out to the tissues
A foreign molecule that causes a specific immune response is a/an
Antigen
Acquired specific immunity involves the response of
B and T lymphocytes
The progeny cells of a B-cell clone are called
Plasma cells
Helper T cells
Activate B cells and other T cells
The histocompatibility complex proteins function in
Recognition of self
The molecular fragment on an antigen molecule that a lymphocyte recognizes and responds to is called a/an
Epitope
Which process involves antibodies covering surface receptors on a virus or toxin molecule thereby disrupting their activity?
Neutralization
Which process involves antibodies cross-linking cells or particles into large aggregates?
Agglutination
Which process involves antibodies coating microorganisms in order to facilitate phagocytosis?
Opsonization
_____ is the most abundant class of antibodies in serum.
IgG
What process provides many B cells and T cells that are activated against specific antigens?
Clonal expansion
Which lymphocytes lack specificity for antigen and are cells that attack cancer cells and virus-infected cells?
Natural killer cells (NK)
Cytotoxic T cells
Secrete granzymes and perforins that damage target cells
The beauty of specific immunity is the production of ____ that provides long-lasting protection
Memory cells
The embryonic yolk sac, the liver and the bone marrow are sites where
Stem cells give rise to immature lymphocytes
Plasma cells
Secrete antibodies
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
Lymphocytes
-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
-Molecular complexity
-Large molecules with a minimum molecular weight of 1,000
-Cells or large, complex molecules
Antigen presenting cells
-Include dendritic cells
-Include macrophages
-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.
Microbial ecology
A collection of organisms together with their physical and chemical factors are called a/an
Ecosystem
Organisms that inhabit soil or water and breakdown and absorb the organic matter of dead organisms are called
Decomposers
Which of the following are primary photosynthesizers?
ALL:
-Green sulfur bacteria
-Cyanobacteria
-Purple sulfur bacteria
-Purple nonsulfur bacteria
The conversion of gaseous nitrogen (N2) to ammonia (NH4+) occurs during
Nitrogen fixation
The oxidation of ammonia (NH4+) to nitrate (NO3-) and nitrite (NO2-) is called
Nitrification
The conversion of nitrate (NO3-) to nitrogen gas (N2) is called
Denitrification
The zone of soil around roots of plants is called the
Rhizosphere
The mutualistic partnership between plant roots and microbes are
Mycorrhizae
Eutrophication
ALL:
- 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
Clostridium perfringens
Gangrene
Clostridium botulinum
Botulism
Bacillus anthracis
Anthrax
Escherichia coli
ETEC
Salmonella enteritidis
Typhoid fever
Streptococcus pyogenes
Scarlet fever
Neisseria meningitidis
Meningitis
Streptococcus pneumoniae
Pneumonia
Treponema pallidum
Syphilis
Neisseria gonorrhea
Gonorrhea
Trypanosoma brucei
Sleeping sickness
Vibrio cholera
Cholera
Plasmodium falciparum
Malaria
Bordetella pertussis
Whooping cough
Yersinia pestis
Plague