Sci 250 week 1 identifying bacteria

Review Figure 6.25 and Table 9.5 of Microbiology.

Access the “Identifying Bacteria” multimedia scenario (http://www.microbelibrary.org/microbelibrary/files/ccImages/Articleimages/shoeb/api20.html) to gain an understanding of the processes involved with identifying and classifying bacteria.

Complete Appendix B located on the student website to classify bacteria and identify a strain of bacteria responsible for a simulated food poisoning outbreak.

 

University of Phoenix Material

 

Appendix B – Identifying Bacteria

 

Bacteria identification is accomplished in a number of ways. Two common tools microbiologists use to identify unknown bacteria include dichotomous key and biochemical tests. The dichotomous key is useful when a microbiologist only needs to know which group an unknown microbe belongs to on a general level. When a microbiologist needs to identify a specific bacterium, biochemical tests are used.

PART ONE: GENERAL BACTERIA IDENTIFICATION

Review the dichotomous key in Figure A, the bacterial shapes in Figure B, and the Gram stain information below. You will use all three to determine to which major group unknown bacteria belong.

 

Figure A:A dichotomous key for classifying major groups of bacteria.
[Figure 9.4 in Microbiology text]

Figure B: The most common bacterial shapes.

[Figure 4.1 in Microbiology text]

 

 

Shape Types:

 

Comma, or Club-shaped, rods = Vibrio

Rods = Coccobacillus, Bacillus

Spherical = Coccus

Spiral or Helical = Spirillium, Spirochete

 

Gram Stain Results:

 

Purple = Gram positive

Red = Gram negative

Neither purple nor red = No cell wall (neither Gram positive nor Gram negative)

 

 

 

Review Figure C on the following page. Use Figure C to identify the type of arrangement displayed by the unknown bacteria. Read through the Sample Identification on the following page for an example of how to identify bacterial groups and arrangements using Figures A, B, C, and the Gram stain results.

Figure C: Arrangement of Bacteria

Rods and Clubs

 

Single

 

 

Strepto-

Cording

 


Snapping

 

 

Palisades

 

 

 

Chinese Letters

 

Cocci

 

 

Single

 

Diplo-

Tetrad

Sarcinae

Staphylo-

Strepto-

 

 

Sample Identification

 

After performing a Gram stain, you observe the following under a microscope:

 

 

(Cells are stained red.)

 

·         Begin with item 1 on the dichotomous key (Figure A). Because the organisms are red, they are not Gram-positive. According to the key, continue to item 3.

·         Because the organism is red (not clear or another color), it is indeed Gram-negative according to item 3. The key directs you to item 5.

·         Consider the shape of individual cells for item 5. According to Figure B, the shape type is closest to spherical. (Note: spherical is circular.)

·         The bacteria belong to the Gram-negative cocci group.

·         Now use Figure C to describe arrangement of bacteria. (The bacteria are not rod- or club-shaped, so focus on the cocci arrangements.) Identify the arrangement that is most prominent.

·         The bacteria are arranged in a diplo- fashion.

·         Enter the group and arrangement in the table.

 

  

Application

 

Use Figures A, B, C, and Gram stain results to identify group and arrangement of bacteria. Continue to Part Two after completing the table.

 

 

 

 

 

 

 

 

View from Microscope

Group of Bacteria

Arrangement

 

(stained red)

Gram-negative cocci

Diplo-

(stained purple)

 

 

(stained purple)

 

 

(stained red)

 

 

(stained red)

 

 

(stained purple)

 

 

(stained purple)

 

 

 

To gain an understanding of the processes involved with identifying bacteria through biochemical tests, access Chapter 6 of the text in WileyPlus located on the Week One course page. Once in WileyPlus (Chapter 6), select the “Bacterial Identification by API” link located under the heading, Take Another Look. Once selected, review the information and watch the Flash-animated movie (animation) located within this link. Then, review the following scenario and answer the questions that follow.

Case Study

A recent outbreak of food poisoning has occurred in a community. One possible source of contamination may be the produce that is grown and distributed locally at a farmer’s market. A test sample of some of the produce revealed evidence of bacterial contamination. The bacteria sample was tested in a microbiology lab and showed the results that follow. The laboratory also performed a Gram stain of the isolated bacteria and ran a number of biochemical tests to aid identification. The biochemical tests were assayed using the Analytical Profile Index (API) 20E system for identification of Enterobacteriaceae and other gram-negative bacteria.

Figure 1. Microbiology laboratory results – Unknown bacteria present on produce (API Results)

 

Figure 2. API Results of Unknown Bacteria in Text Format

Gram stain:
Gram-negative

ONPG

ADH

LDC

ODC

CIT

H2S

URE

TDA

IND

VP

GEL

GLU

Bacteria: Unknown

+

+

+

+

+

 

MAN

INO

SOR

RHA

SAC

MEL

AMY

ARA

+

+

+

+

+

Based on Gram stain results and the knowledge that this bacterium caused food poisoning, the laboratory is able to narrow down the possibilities to three bacterial strains. Figure 3 shows the API results:

Figure 3. API Results of Known Bacterial Strains in Text Format

Gram stain:
Gram-negative

ONPG

ADH

LDC

ODC

CIT

H2S

URE

TDA

IND

VP

GEL

GLU

Bacteria: Salmonella

+

+

 

MAN

INO

SOR

RHA

SAC

MEL

AMY

ARA

+

+

+

 

 

 

Gram stain:
Gram-negative

ONPG

ADH

LDC

ODC

CIT

H2S

URE

TDA

IND

VP

GEL

GLU

Bacteria: Shigella

+

 

MAN

INO

SOR

RHA

SAC

MEL

AMY

ARA

 

Gram stain:
Gram-negative

ONPG

ADH

LDC

ODC

CIT

H2S

URE

TDA

IND

VP

GEL

GLU

Bacteria: E. coli

+

+

+

+

+

 

MAN

INO

SOR

RHA

SAC

MEL

AMY

ARA

+

+

+

+

+

 

Application

Compare the API biochemical test results in Figure 2 (unknown bacteria from produce) with API test results in Figure 3 (known bacterial strains identified in the gray boxes on the left). The bacterial strain in Figure 3 that matches Figure 2 will identify the bacterial strain causing illness. Based upon your observations, which of the bacteria in Figure 3 is the most likely cause of the food poisoning outbreak?

©2008 University of Phoenix. All rights reserved.

 

 

 

SCI 250 MICROBIOLOGY Solution Links, Click the Following link to BUY

Calculate the price
Make an order in advance and get the best price
Pages (550 words)
$0.00
*Price with a welcome 15% discount applied.
Pro tip: If you want to save more money and pay the lowest price, you need to set a more extended deadline.
We know how difficult it is to be a student these days. That's why our prices are one of the most affordable on the market, and there are no hidden fees.

Instead, we offer bonuses, discounts, and free services to make your experience outstanding.
How it works
Receive a 100% original paper that will pass Turnitin from a top essay writing service
step 1
Upload your instructions
Fill out the order form and provide paper details. You can even attach screenshots or add additional instructions later. If something is not clear or missing, the writer will contact you for clarification.
Pro service tips
How to get the most out of your experience with Australia Assessments
One writer throughout the entire course
If you like the writer, you can hire them again. Just copy & paste their ID on the order form ("Preferred Writer's ID" field). This way, your vocabulary will be uniform, and the writer will be aware of your needs.
The same paper from different writers
You can order essay or any other work from two different writers to choose the best one or give another version to a friend. This can be done through the add-on "Same paper from another writer."
Copy of sources used by the writer
Our college essay writers work with ScienceDirect and other databases. They can send you articles or materials used in PDF or through screenshots. Just tick the "Copy of sources" field on the order form.
Testimonials
See why 20k+ students have chosen us as their sole writing assistance provider
Check out the latest reviews and opinions submitted by real customers worldwide and make an informed decision.
Military
excellent work
Customer 456821, November 1st, 2022
Nursing
Awesome! Thanks
Customer 454007, June 19th, 2020
Political science
Great job God bless you
Customer 453983, February 4th, 2020
Nursing
i requested peer reviewed nursing journals as part of my paper, however, I never received them after I requested them twice. If I had received these journals, I would have scored the quality of the paper an 10/10!!!
Customer 461063, October 30th, 2022
Military
Excellent work
Customer 456821, February 26th, 2022
History
excellent!
Customer 463503, October 16th, 2022
Business and administrative studies
Turned in the new assignment,. Everything was great
Customer 463053, December 4th, 2022
Education
Great work. Keep it up
Customer 463647, December 22nd, 2022
Other
Good follow-up task.
Customer 459155, April 7th, 2022
Business and administrative studies
Use Grammarly on all your papers.
Customer 459947, March 28th, 2022
Business and administrative studies
Excellent.
Customer 460073, July 9th, 2022
project management
thank you
Customer 462327, November 16th, 2022
11,595
Customer reviews in total
96%
Current satisfaction rate
3 pages
Average paper length
37%
Customers referred by a friend
OUR GIFT TO YOU
15% OFF your first order
Use a coupon FIRST15 and enjoy expert help with any task at the most affordable price.
Claim my 15% OFF Order in Chat