Lab Final

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What is WHMIS?: Workplace
Hazardous
Materials
Information
System
What are the 3 key elements of WHMIS?: 1) Labels
2) Material Safety Data Sheets (MSDS's)
3) Worker Education
How do you determine total magnification?: Total Magnification = ocular x objective
What are the characteristics of E.Coli?: -stains gram neg
-rods
-single
What are the 3 shapes of bacteria?: 1) spherical/coccus
2) rod/bacillus
3) helical/spirillum
What are the characteristics of Staphylococcus aureus?: -gram stain pos
-coccus
-grape-like clusters
What are the characteristics of Bacillus cereus?: -gram stain pos
-bacillus
-large rods in chains
What's the purpose in using: 1) Methylene Blue Stain? 2) Gram Stain? 3) Spore Stain?: 1) improves contrast of organisms
2) helps differentiate and classify depending on color
3) helps see spores within bacterial cells
What's the purpose of performing: 1) Negative stains 2) Acid-fast Stain: 1) see silhouette of bacteria
2) identifies acid-fast bacteria by staining it red or pink
Why is blood agar used as a growth medium?: -provides the nutrients for growth of most bacteria
-relatively non-selective
Why is Mannitol Salt Agar used as a growth medium?: -selective for staphylococci
-also as an indicator that changes red to yellow when acid end products are produced
-usually used to differentiate S.aureus(yellow) and S.mepidermidis(red)
Why is MacConkey's Agar used as a growth medium?: -simulates the environment of the stomach
-therefor is selective towards the bacteria that would be found in stomach and intestine
-useful for stool specimens
-ie: Escherichia, Citrobacter, Klebsiella, Enterobactera

**if acidic, plate turns red to pink**
What are the 5 names and effects of oxygen on microbial growth?: 1)obligate aerobes - need it
2)obligate anaerobes - die from it
3)facultative anaerobes - grow best with it, can do without
4)aerotolerant organisms - can do with or without
5)microaerophilic organisms - grow best at low conc.
What methods are used to count bacteria (CFU's): -Turbidity
-Pour Plate Method
-Spead Plate Method
Why is XLD used as a growth medium?: -differential and selective medium used for the isolation of enteric pathogens (ie: salmonella)
-if carbon sources are fermented, well result in yellow colonies
How do you determine the initial concentration of bacteria from diluted sample?: CFU x (1/final dilution) x (1/volume sampled)
What is sterilization?: -the use of physical or chemical procedure to destro or remove all microbial life.
What is Disinfection?: -the treatment of inanimate objects to reduce the level of microorganisms
What is antisepsis?: -the treatment of living tissue to inhibit or destroy microorganisms
Are disinfectants more effective agains gram positive or gram negative bacteria?: -more effective agains gram positive (ie: S. aureus)
Define: 1) resident flora 2) transient flora: 1) permanent flora
2) temporary flora
What is 'oligodynamic action'?: - the ability of small amounts of heavy metals to exert a lethal effect on bacteria
When applying the Kirby-Bauer Disc Diffusion method, what is the resistive, intermediate, and sensitive zone?: -Resistive zone is closest to the disc
-next is intermediate zone
-furthest is the sensitive zone
What does M.I.C. stand for?: -Minimum Inhibitory Concentration
-The highest dilution of antibiotic showing no growth of the test organism
What does M.B.C. stand for?: -Minimal Bactericidal Concentration
-the dilution at which the effects of the antibiotic are not reversible

**to check for MBC, culture the dilution tubes that show no growth. The lowest dilution which has less than 30 CFU's is the dilution for MBC**
What are synergistic effects?: -the effects of the antibiotics used in combinaion is signigicantly greater than their effects when used individually
-if the drugs are synergistc, the 2 inhibitory zones will merge to from a bridge at their juncture
What is the purpose of performing the Indole Test?: -tests for the ability of certain bacteria to decompose the amino acid tryptophan to indole

-a deep red color deveolps in the presence of indole
What is the purpose of performing the methyl red test?: -tests for the productio of a prolonged acidity from glucose utilization by an organism growing in a buffered medium

-positive = bright red
-weakly positive = orange red
-negative = yellow
What is the purpose of performing the Voges-Proskauer reaction test?: -tests for the productio of acetyl-methyl-carbinol from glucose

-a pink to red colour within 5-30mins indicates a positive reaction
What is the purpose of performing the Citrate test?: -tests the ability of an organism to use sodium citrate as its only cource of carbon energy and ammonium salts as only source of nitrogen

-if the organism can use these substances, indicator turns from green to blue
What is the purpose of performing a urease test?: -used to test if bacteria can decompose urea by means of the enzyme urease
What is the purpose of performing Phenylpyruvic acid test?: -tests for the ability of organisms to deaminate phenylalanine

-a green color developing in the slant and free fluid indicates a positive test
What is the purpose of performing the Kligler's Iron Agar (KIA) test?: -tests for acidity, gas, H2S
-check pg 7-6 for all this shit
What is the purpose of performing the motility test?: -to see how well bacteria moves
-motles bacteria swim outward from the stab line into the surrounding media
What is the purpose of performing an API 20E test?: -a standardized, miniaturized version of conventional procedure for the identification of Enterobacteriaceae and other Gram-negative bacteria
What bacterial species are the majority in the upper respiratory tract?: -Streptococcal, Saphylococcus, Neisseria and Haemophilus species
What is the purpose of performing a Catalase test?: -used to differentiate gram postive cocci
-ie:
->streptococcus species catalase neg (no gas)
->staphylcoccus species catalase pos
(gas)
We know that if a catalase test yields a negative result (ie: no gas), then we have a Streptococcus group species. How do you further differentiate this group?: -Hemolysis

-Alpha hemolysis: Partial breakdown
-Beta hemolysis: Total breakdown
-Gamma hemolysis: No reaction on media
What is Borella vincettii and Fusobacterium fusiforme?: -B. vincentii is a gram neg spirochaete with 6-8 waves

-F. fusiform is a gram neg rod characterized by pointed ends

**Both are causes of Vincent's angina**
What is mycology?: -the study of yeasts and molds
What's the difference between yeasts and molds?: -yeasts are unicellular fungi and larger then bacteria cells

-molds are multicellular fungi and have a filamentous structure called hyphae
What is the purpose of using Sabouraud's agar as a grow media?: -used to grow fungi
What is: 1) Saccaromyces cerevisiae 2) Candida albicans 3) Rhizopus sp 4) Aspergillus niger 5) Penicillium notatum: 1) a true unicellular yeast
2) a yeast like fungus
3) a tue mold
4) a pigmented mold
5) a bluish mold
What are the 5 types of blood cells found in human blood?: 1) neutrophils
2) eosinophils
3) basophils
**Phagocytic cells with granules**

4) lymphocytes
5) monocytes
**These don't have granules**
What is a differential count?: -the total number of white cells/ml of blood and the relative % of the different tyhpes of white blood cells
What is an agglutination reaction?: -a very simple way of demonstrating an antibody & antigen reaction
-if antibody matches antigen, solution thickens up, that's how you know if it works
What must you know before prescribing an antibiotic?: -it's mode of action
-possible adverse side effects in the host
-range of it's antimicrobial activity
What 9 sections must MSDS's provide?: 1) product informatio
2) hazardous ingredients
3) physical data
4) fire or explosio hazard
5) reactivity data
6) toxicological properties
7) preventive measures
8) first aid measures
9) preparation information
What are the 3 categories of fungi?: 1) Yeast colonies
2) Yeast-like colonies
3) Filamentous-type colonies

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