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144 Cards in this Set
- Front
- Back
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Know the steps in culturing microorganisms.
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A. Inoculation –introduce a tiny sample into nutrient medium (inoculums).
B. Isolation –separating cells. C. Incubation –inoculated medium is placed in an incubator. D. Inspection –cultures are examined and evaluated macroscopically. E. Identification –species is determined. |
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Prokaryotes
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Do not contain a nucleus or organelles, usually smaller than eukaryotes,
Ex: ALL BACTERIAS. |
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Eukaryotes
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Organisms composed of a cell or many cells that have a nucleus and organelles.
Ex: Fungi, Protists, and Helminth worms. |
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Unicellular
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Composed of one cell
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Multi-cellular
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Consisting of many cells
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Free-living
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A lifestyle usually in soil or water, harmless, even beneficial. Some have symbiotic relationship with other organisms
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Parasitic
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Living in or on a host from which nourishment is derived while causing damage. Ex: worms
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Spread plate
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Liquid inoculums is pipette onto the surface of a solid medium and spread around
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Streak plate
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Inoculum is spread over the surface of a solid medium
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Pour plate or loop dilution
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Inoculum is introduced onto a series of liquid media, the poured out into a petri dish
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What is a hockey stick?
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An instrument used to spread inoculums around
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Periplasmic
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Internal flagella located between the cell wall and the cell membrane to create a wriggling motion in spirochetes. {Around}
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Peritrichous
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Flagella are randomly placed all over the cell’s surface
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Lophotrichous
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Tufts of flagella at one site
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Amphitrichous
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Flagella at both ends
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A. Inoculation –introduce a tiny sample into nutrient medium (inoculums).
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B. Isolation –separating cells.
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C. Incubation –inoculated medium is placed in an incubator.
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D. Inspection –cultures are examined and evaluated macroscopically.
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E. Identification –species is determined.
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A. Prokaryotes –do not contain a nucleus or organelles, usually smaller than eukaryotes,
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Ex: ALL BACTERIAS.
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WHAT ARE THE PARTS OF THE CELL ENVELOPE?
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The cell membrane and the cell wall.
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6.
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Distinguish among:
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7.
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Distinguish between gram+ and gram- cells by describing the cell wall and periplasmic space.
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8.
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Describe rickettsias and name a disease caused by a rickettsia. Rickettsias are tiny, gram- bacteria, must be in a host cell to survive, and is the agent for Rocky Mountain spotted fever.
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9.
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Distinguish between the trophozoite and cyst stages of protists.
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A. Trophozoite –active feeding stage.
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B. Cyst –dormant, resting stage that allows the protozoan to survive adverse situations. [Entamoeba histolytica and Giardia lamblia can be transmitted in the cyst stage.]
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10.
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What is a prion? Prions or proteinaceous infectious particles are naked protein molecules. No DNA or RNA, but are capable of causing infections.
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What human diseases do prions cause? Transmissible spongiforms-- Bovine spongiform encephalopathy (mad cow disease), Creutzfeldt-Jakob, kuru, fatal familiar insomnia.
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How do they affect the patient? There is no treatment. Deterioration of the brain, loss of motor coordination, sensory and cognitive abilities precede death.
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Rate prions resistance to heat, radiation, and other microbial controls. Prions are highly resistant to disinfectants and radiation. Very high temperatures and treatment with strong alkaline chemicals can deactivate them.
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11.
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Distinguish among:
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A. Psychrophile –optimal temp. Is below 25 degrees C and grow at 0 degrees C. rarely pathogenic.
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B. Mesophile –have optimal temp. Between 20 degrees C and 40 degrees C. Most human pathogens.
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C. Thermophile –grows best at greater than 45 degrees C.
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12.
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Name in order the stages in the normal bacterial growth curve.
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I. Lag phase –early period, no or slow growth. {New environment}
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II. Log or Exponential growth phase –Growth curve increases. {Maximum growth}
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III. Stationary growth phase –curve levels off, cells stop growing. {Some growth, some death}
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IV. Death phase –cell death accelerates to exponential rate as conditions deteriorate.
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13.
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What are the components of all viruses? All viruses have a protein shell or capsid that surrounds the nucleic acid (either DNA or RNA). Viruses have either RNA or DNA not both; they are surrounded by a capsid, and have no cell wall.
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14.
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Know the stages and events of the multiplication cycle of an animal virus.
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A. Adsorption –attachment to specific receptor sites on the cell membrane. (stick)
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B. Penetration/uncoating –the entire virus or just the nucleic acid enters the cell. (Entry into cell)
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C. Synthesis –replication and protein synthesis.
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D. Assembly –Virus particles are constructed from the accumulating components. (Put together)
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E. Release –non-envelope and complex (cell lyses), enveloped (budding or exocytosis)
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15.
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What elements are present in ALL organic molecules? At least some combination of carbon and hydrogen.
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16.
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What are the products of fermentation?
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A. Alcoholic fermentation –produces ethanol and carbon dioxide.
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B. Acidic fermentation –a. Pyruvate is reduced to lactic acid and or other acids.
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17. ?
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What is the ultimate electron acceptor in the ETS of cellular respiration? Electron transport chain or system (ETS) –chain of redox carriers that electrons from NADH and FADH from glycolysis and TCA cycle. Oxygen is the final electron acceptor and water is produced.
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18.
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What is the effect of streptokinase? Streptokinase’s is an enzyme that digests blood clots to assist invasion of wounds.
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19.
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What is the action of chloramphenicol in microbial control? Chloramphenicol binds to ribosomes where proteins are assembled so proteins can’t be assembled.
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20.
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Name two halogens most often used in microbial control. Chlorine and Iodine.
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21.
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Rate the resistance from greatest to least of: B-C-N-E-T
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Highest resistance: 1. Bacterial endospores
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Least resistance:
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4. Enveloped viruses 5. Trophozoites
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22. ?
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What method is used to produce multiple copies of DNA? Reverse transcriptase.
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23.
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Describe how an adenovirus has been modified for medical purpose. An adenovirus that causes colds has altered DNA that makes it attack and lyse cancer cells.
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24.
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Distinguish between exotoxins and endotoxins.
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A. Endotoxins –are inside the body, require high doses to be toxic, effects; systemic: fever, inflammation, stimulates fever, released from cell wall during lysis, source: all gram-.
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B. Exotoxins –are outside the body, minute amounts to be toxic, effects; specific to cell type, immune response; stimulates antibodies, fever not usually associated with, secreted by cell, source; few gram+,gram neg.
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25.
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Know the stages in development of infection and disease.
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1. Incubation period
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2. Prodromal stage
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3. Period of invasion
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4. Convalescent period
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26.
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What are the purposes of pasteurization? Disinfection of beverages while preserving flavor and nutrients.
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27.
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What is the effect of boiling water or steam in biological control? They are physical controls (moist heat); main effect is coagulation of proteins. Most processed foods use moist heat.
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28.
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Describe ionizing radiation in the sterilization of food. Ionizing radiation (gamma rays, X-rays, Cathode rays) used in preserving food: kills bacterial pathogens, insects, and worms. Does not make food radioactive.
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29.
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Against which pathogens is hydrogen peroxide effective as a control? Effective against bacteria, viruses, fungi, and spores by the action of oxygen that forms hydroxyl free radicals that are highly reactive to cells.
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Why is it effective against anaerobes, especially? Effective against anaerobic bacteria because of the oxygen.
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30.
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Distinguish among:
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Morbidity –number of persons afflicted with infectious disease.
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Mortality –total number of deaths in a population due to a certain disease.
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Prevalence –of a disease is the total number of existing cases relative to the entire population.
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Incidence –number of new cases over a certain period of time.
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31.
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Distinguish among:
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Epidemic –prevalence increases above w hat is expected.
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Pandemic –spread of epidemic across continents.
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Endemic –an infectious disease with relatively steady frequency over a long period.
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32. ?
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Why is aflatoxin so dangerous? Aflatoxin is an intoxicant acquired through air-born spores produced by aspergillus flavus and is carcinogenic and hepatoxic, a cofactor in liver cancer.
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33.
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Why is it so difficult to develop immunity to rhino virus? Because there are so many different ones and you need to develop a vaccine for all of the different knobs.
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34.
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What are the agent, vector and effects of Changas disease? Changas disease is caused by Trypanosoma cruzi, vectored by the kissing bug. Causes an enlarged heart.
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35.
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What is the agent for most stomach ulcers? Helicobacter pylori –agent for 90% of stomach and duodenal ulcers and a cofactor in development of a type of stomach cancer.
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36.
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How is Giardia lamblia transmitted? A protozoan parasite Giardia lamblia, a mastigophoran, is the agent for giardias. Transmission is usually by cysts that are deposited in the environment and then ingested. (Cattle, cats, humans)
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37.
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What are some characteristics of Candida albicans? Candida albicans are opportunistic mycoses, normal flora of 20% of humans, usually endogenous, but can spread in nurseries, through surgery, childbirth, and sexual contact. Infections usually involve mucous of membranes mouth (thrush) and vagina (yeast infections).
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38.
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What is the scientific method? An objective strategy for establishing hypothesis, an explanation for a phenomenon.
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Distinguish between hypothesis and theory. The hypothesis is a statement that can be tested by observation or experimentation. As acceptance becomes widespread the hypothesis is considered to be a theory, an explanation for a natural event.
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39.
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What are Koch’s Postulates? Principle criteria for etiologic studies, i.e., what cause a certain disease.
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A. Find evidence of a particular microbe in every case of a disease.
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B. Isolate that microbe from an infected subject, cultivate it artificially in the lab.
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C. Inoculate a susceptible healthy subject with the lab isolate and observe the same resultant disease.
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D. Re-isolate the agent from this subject.
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40.
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Define:
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A. Virion –fully formed virus able to establish an infection.
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B. Viriod –naked strands of RNA are pathogens on tomatoes, potatoes, cucumbers, citrus trees, and chrysanthemums.
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C. Commensal –one organism, the commensal, benefits, and the other organism is neither hurt nor helped.
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D. Axenic –a sterile state as a pure culture. (germ-free)
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E. Pure Culture –a culture that is composed of one known microorganism. Also Axenic.
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F. Asepsis –any practice that prevents the entry of infectious agents into sterile tissues and thus prevents infection.
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G. Sepsis –presence of microorganisms or their poisonous products in the bloodstream and other tissues.
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H. Chemotaxis –is movement in response to chemical signals toward (positive) or away from (negative).
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I. Sterile –absence of life.
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J. Microbicidals –agents are designed to kill a specific pathogen...
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K. Microbistatics –agents that prevent growth of bacteria on tissues or objects.
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41.
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Compare the vulnerability of young and old microbes to disinfecting agents. Age of microbe: Younger, more active is more vulnerable. Older, sedate ones, less so.
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42.
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When may the infection of eggs by salmonella occur? Eggs can be contaminated even before the hen lays them.
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43.
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What is the effect of an enzyme on rate of reaction? Enzymes work as catalysts that increase the rate of a chemical reaction but are not part of the reactants or products.
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44. ?
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What is a common method for sterilizing used in the lab? Autoclave.
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45.
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What are the vector and agent for Lyme disease? Borrelia burgdorferi is the agent for Lyme disease and is vectored by hard ticks with mice and deer reservoir.
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46.
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Evaluate ethylene oxide as a sterilant. It is an effective sterilant, blocks DNA replication and enzymatic actions. A sporicide. Rather penetrating but slow-acting.
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47.
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Identify the cloning host and genetic donor in recombinant DNA technology.
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48.
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What are some uses of UV radiation in disinfection? Non-ionizing radiation: ultraviolet rays (UV), disinfection rather than sterilization; UV lamps are used to disinfect air in hospital rooms, reduce growth of microbes in food processing plants, and purify drinking water, milk, and fruit juices.
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49.
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Name some countries in which the plague is endemic. Africa, South America, Mideast, Asia, countries of the former USSR, US experiences a few cases.
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50.
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Identify the agent of:
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A. Cholera –Vibrio cholera. Gram- bact.
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B. Diphtheria –Corynebacterium diphtheria. Gram+ bacilli
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C. Gas gangrene - Clostridium –Clostridium perfringens cause gas gangrene.
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D. Hansen disease –Mycobacterium leprae.
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E. MRSA (methicillin resistant S.aureas) –Staphylococci, Staphylococcus aureus.
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F. Rocky Mountain Spotted Fever –Rickettsia rickettsii.
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G. Scarlet fever –Streptococci, Streptococcus pyrogenes.
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H. Toxic shock syndrome –Staphylococci,
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I. Typhoid fever –Rickettsia , Rickettsia prowazekii.
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J. Walking pneumonia –Mycoplasmas, Mycoplasma pneumonia.
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51.
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Define:
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A. Aerosols –suspensions of dust or moisture particles that contain pathogens.
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B. Biological vector –actively participates in microbe’s life cycle.
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C. Carrier –an individual who inconspicuously houses a pathogen and spreads it to others.
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D. Droplet nuclei –microscopic pellets of mucous and saliva ejected by a sneeze or cough.
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E. Fomite –inanimate object that harbors and transmits pathogens: doorknobs, ect.
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F. Mechanical vector –Transport only. Animals can carry the agent on their body surface.
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G. Nosocomial –infections not present upon admission to hospital but incurred while being treated.
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H. Reservoir –primary habitat in the natural world.
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I. Source –the individual or object from which an infection is acquired.
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J. Zoonosis –an infection indigenous to animals but transmittable to humans: rabies, plague.
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