Selective and Differential Media Questions

docx

School

University Of Arizona *

*We aren’t endorsed by this school

Course

181R

Subject

Biology

Date

Apr 3, 2024

Type

docx

Pages

9

Uploaded by KidFlag6034

Report
Selective and Differential Media Questions Mannitol Salt Agar Escherichia coli Growth on Mannitol Salt Agar (yes or no) Mannitol Salt Agar Medium Color (red or yellow) 24-hour observation 48-hour observation 72-hour observation Staphylococcus epidermidis Growth on Mannitol Salt Agar (yes or no) Mannitol Salt Agar Medium Color (red or yellow) 24-hour observation 48-hour observation 72-hour observation Paste the Required Photos Below: 1. What chemical in MSA makes it selective media? How? 2. What chemical makes MSA a differential media? How? 3. Did you observe any growth on your MSA plate? Did you observe any color change on your MSA plate?
4. What color does MSA appear with the growth of Staphylococcus aureus ? What color does MSA appear with the growth of Staphylococcus epidermidis ? 5. Below is a photo of an inoculated, incubated mannitol salt agar plate. Is the organism growing on the right hand side of the plate Gram-positive or Gram-negative? Does the organism on the right-hand side of this plate ferment mannitol? 6. How do we identify hospital staff as carriers of Staphylococcus aureus ? 7. How is S. aureus transmitted? 8. How can MRSA infections be prevented? 9. The microbiology department is celebrating the end of the school year in May by holding its traditional picnic. The speeches drag on for a couple of hours, but finally all the faculty and students can dig into the food: chicken salad, tomatoes, onions, salad, and custard pie. By evening, the whole department, except for two vegetarian students who did not eat the chicken salad, is stricken with nausea, vomiting, retching, and abdominal cramping. Several individuals complain of diarrhea. One patient shows signs of shock (low blood pressure). Blood and stool samples are collected from patients, and an analysis of all foods served at the meal is conducted. Bacteria can cause gastroenteritis (inflammation of the stomach and intestinal tract) either by colonizing and replicating in
the host, which is considered an infection, or by secreting toxins, which is considered intoxication. Signs and symptoms of infections are typically delayed, whereas intoxication manifests within hours, as happened after the picnic. Blood samples from the patients showed no signs of bacterial infection, which further suggests that this was a case of intoxication. Since intoxication is due to secreted toxins, bacteria are not usually detected in blood or stool samples. MacConkey agar results ruled out E. coli , Salmonella , and Shigella . Analysis of the chicken salad revealed an abnormal number of gram- positive cocci arranged in clusters. A culture of the gram-positive cocci releases bubbles when mixed with hydrogen peroxide. The culture turned mannitol salt agar yellow after a 24-hour incubation. A. What Genus and species of bacteria gave the picnic goers food poisoning? B. Is the intoxication caused by an exotoxin or endotoxin? Please explain. MacConkey Agar Escherichia coli Growth on MacConkey Agar (yes or no) Colony Color (colorless or pink) 24-hour observation 48-hour observation 72-hour observation Staphylococcus epidermidis Growth on MacConkey Agar (yes or no) Colony Color (colorless or pink) 24-hour observation 48-hour observation 72-hour observation Paste the Required Photos Below: 1. What type of bacteria are inhibited from growing on MacConkey agar? What ingredients in MacConkey agar selects against those bacteria?
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
2. What ingredient makes MacConkey agar differential? 3. What color colonies are produced on MacConkey agar by organisms that ferment lactose? 4. Below is a photo of an inoculated, incubated MacConkey agar plate. Is the organism growing on this plate Gram-positive or Gram-negative? Does this organism ferment lactose? 5. Did you observe any growth on your MacConkey plate? Did you observe any color change on your MacConkey plate?
Levine EMB Agar Escherichia coli Growth EMB Agar (yes or no) EMB Agar Medium Color (dark purple, dark purple with metallic sheen, light purple, colorless/color of the medium) 24-hour incubation 48-hour incubation 72-hour incubation Staphylococcus epidermidis Growth EMB Agar (yes or no) EMB Agar Medium Color (dark purple, dark purple with metallic sheen, light purple, colorless/color of the medium) 24-hour incubation 48-hour incubation 72-hour incubation Paste the Required Photos Below: 1. What type of bacteria are inhibited from growing on EMB agar? What ingredients in EMB agar selects against those bacteria? 2. What ingredient makes EMB agar differential?
3. What color does the growth appear on EMB agar when the organism ferments lactose? 4. Below is a photo of an inoculated, incubated EMB plate. Is this organism Gram-positive or Gram-negative? Does this organism ferment lactose? 5. Did you observe any growth on your EMB plate? Did you observe any color change on your EMB plate? TSI Agar Use the table below to determine the symbols for the TSI agar Symbol After 24 Hour Incubation Symbol After 48 Hour Incubation Symbol After 72 Hour Incubation Control Escherichia coli Staphylococcus
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
epidermidis Results (slant/butt) Symbol Interpretation Red/Yellow K/A Fermentation of glucose only; Protein used for aerobic energy production in the slant Yellow/Yellow A/A Fermentation of glucose, plus fermentation of lactose and/or sucrose Red/Red K/K No fermentation: Protein used for aerobic energy production in the slant and anaerobic energy production in the butt Red/No Color Change K/NC No fermentation: Protein used for aerobic energy production in the slant Yellow/Yellow with Bubbles A/A, G Fermentation of glucose, plus fermentation of lactose and/or sucrose, with gas production Red/Yellow with Bubbles K/A, G Fermentation of glucose only, with gas production; Protein used for aerobic energy production in the slant Red/yellow with Bubbles and Black Precipitate K/A, G, H 2 S Fermentation of glucose only, with gas production; Protein used for aerobic energy production in the slant; H 2 S produced Red/Yellow with Black Precipitate K/A, H 2 S Fermentation of glucose only; H 2 S produced Yellow/Yellow with Black Precipitate A/A, H 2 S Fermentation of glucose, plus fermentation of lactose and/or sucrose; H 2 S produced No Change/No Change N/C. N/C No growth Paste the Required Photos Below: 1. What are the three types of sugars present in the TSI?
2. How was the inoculum added to both the butt and the slant of the TSI agar? 3. What color is visibly observed if the organism ferments any of the three sugars present in the medium? 4. What is visibly observed if the organism produces gas when it ferments a sugar present in the medium? 5. What is visibly observed if the organism uses anaerobic energy production with thiosulfate in the TSI medium as the final member of the electron transport chain? 6. Use the table above to determine the symbol for each of the inoculated, incubated TSI agar tubes in the photo below. Record the symbols in the table below. 1 2 3 4 TSI Agar Tube Symbol
1 2 3 4
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help

Related Documents

Post UW 1.docx
Streak Plate Questions.docx
Anaya Fatima - 2 RBio Enzyme Lab 2022 - 10144912.pdf
Kirby-Bauer Test Questions.docx
Anemia Bio1010.pdf
DNA Subway Lab Notebook Template.docx
Lab 02 Critical Thinking Questions.pdf
Lab Exercise 06.pdf
OwlPelletLabAssignment (1).docx
Lab 02 Exercise 01.pdf
Lab 02 Concept Review Questions.pdf
Lab 02 Exercise 03.pdf
Recommended textbooks for you
Text book image
Biomedical Instrumentation Systems
Chemistry
ISBN:9781133478294
Author:Chatterjee
Publisher:Cengage
Text book image
Principles Of Pharmacology Med Assist
Biology
ISBN:9781337512442
Author:RICE
Publisher:Cengage
Text book image
Microbiology for Surgical Technologists (MindTap ...
Biology
ISBN:9781111306663
Author:Margaret Rodriguez, Paul Price
Publisher:Cengage Learning
Text book image
Basic Clinical Laboratory Techniques 6E
Biology
ISBN:9781133893943
Author:ESTRIDGE
Publisher:Cengage
Text book image
Curren'S Math For Meds: Dosages & Sol
Nursing
ISBN:9781305143531
Author:CURREN
Publisher:Cengage
Text book image
Essentials of Pharmacology for Health Professions
Nursing
ISBN:9781305441620
Author:WOODROW
Publisher:Cengage
SEE MORE TEXTBOOKS
Recommended textbooks for you
Text book image
Biomedical Instrumentation Systems
Chemistry
ISBN:9781133478294
Author:Chatterjee
Publisher:Cengage
Text book image
Principles Of Pharmacology Med Assist
Biology
ISBN:9781337512442
Author:RICE
Publisher:Cengage
Text book image
Microbiology for Surgical Technologists (MindTap ...
Biology
ISBN:9781111306663
Author:Margaret Rodriguez, Paul Price
Publisher:Cengage Learning
Text book image
Basic Clinical Laboratory Techniques 6E
Biology
ISBN:9781133893943
Author:ESTRIDGE
Publisher:Cengage
Text book image
Curren'S Math For Meds: Dosages & Sol
Nursing
ISBN:9781305143531
Author:CURREN
Publisher:Cengage
Text book image
Essentials of Pharmacology for Health Professions
Nursing
ISBN:9781305441620
Author:WOODROW
Publisher:Cengage
SEE MORE TEXTBOOKS