You are working in a food safety lab and were given some samples to evaluate for microbial contamination. The particular sample youâre working with today is a potato purchased at local farmerâs market booth. This farm does not use organic growth techniques. You swabbed the potato and performed a T-streak on MacConkey agar. From this you isolated several different colony morphologies, but one was of particular interest. The colonies were round and very glossy. On MacConkey agar they develop a reddish color.
You amplified one of these colonies for further analysis.
1. You prepare a wet mount and observe the microorganism under high magnification. You find that it has a rod shape and is non-motile.
2. You inoculate a thiolglycolate tube with this organism and incubate it overnight. Results are shown below.
Growth in Thiolglycolate (it is cloudy all the way to the bottom)
3. You inoculate a BD Enterotube with your unknown isolate. The results are shown below.
1 2 3 5 6 7 8 9 11 12
Glucose Lysine Ornithine Adonitol Lactose Arabinose Sorbitol V/P Urea Citrate
Color Yellow Purple Yellow orange yellow yellow yellow red pink blue
Gas? Yes
Note: I left out chambers 4 and 10 since you have no experience reading them and interpreting the results. The organism is negative for Indole, H2S, Dulcitol, and PA.
â
Case Study 4
Name: ____________________________________
Questions:
1. How would you classify this organism based on oxygen tolerance?
2. What is the scientific name of your microbe?
3. Describe the process you used to come to this result.
4. Is this a microbe that would be expected on produce?
5. Is this microbe a pathogen? Is it an opportunistic pathogen?
You are working in a food safety lab and were given some samples to evaluate for microbial contamination. The particular sample youâre working with today is a potato purchased at local farmerâs market booth. This farm does not use organic growth techniques. You swabbed the potato and performed a T-streak on MacConkey agar. From this you isolated several different colony morphologies, but one was of particular interest. The colonies were round and very glossy. On MacConkey agar they develop a reddish color.
You amplified one of these colonies for further analysis.
1. You prepare a wet mount and observe the microorganism under high magnification. You find that it has a rod shape and is non-motile.
2. You inoculate a thiolglycolate tube with this organism and incubate it overnight. Results are shown below.
Growth in Thiolglycolate (it is cloudy all the way to the bottom)
3. You inoculate a BD Enterotube with your unknown isolate. The results are shown below.
1 2 3 5 6 7 8 9 11 12
Glucose Lysine Ornithine Adonitol Lactose Arabinose Sorbitol V/P Urea Citrate
Color Yellow Purple Yellow orange yellow yellow yellow red pink blue
Gas? Yes
Note: I left out chambers 4 and 10 since you have no experience reading them and interpreting the results. The organism is negative for Indole, H2S, Dulcitol, and PA.
â
Case Study 4
Name: ____________________________________
Questions:
1. How would you classify this organism based on oxygen tolerance?
2. What is the scientific name of your microbe?
3. Describe the process you used to come to this result.
4. Is this a microbe that would be expected on produce?
5. Is this microbe a pathogen? Is it an opportunistic pathogen?
