Download Microbiology Lab Midterm Review - ASM @ UCF

Mcb3020 Lab Practical
Review
Spring 2013
Brought to you by:
Alisha Kellner & Robért Wingo
General Information
• Practical will be station based.
• Will take place on Wednesday the 10th during your lab
time.
• *Disclaimer*
– We are not professors and do not have access to the test.
– The review is based off of our knowledge (as TA’s and past
students) as well as the lab packet and PPT’s.
– Any information given to you in lab or lecture is fair game for
the practical and may or may not be included in the review.
– If you find a discrepancy between what we tell you and what
your professor told you, please go by what the professor says.
Additional questions
• Contact info:
– [email protected] (Alisha)
– [email protected] (Robért)
• Feedback is encouraged
– www.asmucf.com
Material covered
• Any information given to you in lab or lecture is fair
game for the test.
• Majority comes from your lab packet available on
webcourses.
• Also be familiar with the PPT’s
• Know which reagents go with which tests
• Know what EVERYTHING looks like.
• Know how to read a positive or negative result.
• Know characteristic organisms
– Ex: EC has a metallic green sheen on EMB
– Ex: Staph is catalase positive, etc.
Material Covered cont.
• Everything from your midterm
• Pages 1-7 + IMViC, Gelatinase,
Litmus, & Motility
• You should already know:
– Microscope & staining basics
– Differential & selective media
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PEA
DES
EMB
BA
Starch
Milk
Lipase
– Biochemical tests
• Sugar fermentation
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MRVP
Catalase
Oxidase
Motility
Nitrate
Indole
Urea
H2S
SIM
Simmons Citrate
Phenylalanine
Litmus Milk
IMViC
Biochemical Tests
• KIA: Kliger’s Iron Agar
– Sugar fermentation, H2S production, gas production
– Indicator: phenol red
– Inoculation? Read results?
• OF glucose
– Glucose via oxidative or fermentative means
– Inoculation? Results?
– Indicator: Bromthymol Blue
• BSA: Bismuth Sulfide Agar
– What’s it look like? Results?
• BGA: Brilliant Green Agar
– Lactose/sucrose fermentation.
– Indicator: Brilliant green
– Results??
Biochemical Results
• SS agar: Salmonella & Shigella
– Results?
• Desoxycholate Citrate
– Selective?
– Indicator: Neutral Red
• Coagulase
– Only valid for gram +
• MSA: mannitol salt agar
– Selective? Differential?
– Indicator: phenol red
• Staph 110 medium
– Selective? Differential? Indicator?
– Like MSA but w/o phenol red. Why?
• DNase
– Selective? Differential? Indicator? Inoculation?
Biochemical Tests
• M-staphylococcus
– 10% NaCl, why?
• Endo agar
– Selective? Differential? Results?
– Golden metallic sheen
Staphylococcus
• Found?
• Cell morphology?
• Cell characteristics? (gram? What does that
tell you about cell well?)
• Aureus, Epidermidis, Saprophyticus
– Which is coagulase positive
• Catalase, MSA, SM110
Streptococcus
• Found?
• Cell morphology?
• Cell characteristics? (gram? What does that
tell you about cell well?)
• Pyogenes, Pneumoniae, Agalactiae
• Catalase? PEA?
Studies
• Gram + cocci study
– Have a basic understanding of what happens on each day and why?
– Know how to differentiate between Staph and Strep and also between
spp. (read: look at gram + dichotomous key)
• Gram – Intestinal pathogens
– What was the purpose of this study?
– Know the days and what happens on each and why?
– Be able to differentiate between organisms (gram – dichotomous key)
• Standard plate count
– Why? How? Rules?
• DF= A/(A+B)
• Plated DF = A/1mL
Studies
• Direct microscopic count
– Why? How?
– Xylene, EtOH, immerse in H2O, methylene blue, H2O,
EtOH, H2O
– Breed slide, stage micrometer
– Formulas:
• # organisms/mL = (avg # bacteria/FOV) * microscopic factor
* 1/DF
– Avg # bacteria/FOV
– Dilution factor
– Microscopic factor
Studies
• Bacterial examination of water
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What? Why? How?
Presumptive: 9-12 tubes of lactose broth, MPN
Confirmative: EMB or endo
Completed: lactose broth and NA slants
IMViC; EA vs EC
Membrane filter method: how does it work? What does it
look like?
• Antiseptic evaluation
– Filter paper disk method
– Kirby-Bauer Method
– MIC
Hint: this is E coli
OF-Glucose
Good Luck!
• [email protected]
• [email protected]
• Feedback:
www.asmucf.com