Microbiology Intro: Three MRSA cells get deep inside the cut. the generation tim

Question

Microbiology

Intro: Three MRSA cells get deep inside the cut. the generation time of MRSA under the growth condition in the wound is 4 hrs.

Six MRSA from the cut get into the patient's bloodstream. When the patient is rushed into ICU, she has 180 cfu of MRSA/mL of blood. She has a total of 3.5 L of blood in her body. How many total cfu are in her blood now?

Part 2: In the patient's bloodstream, the MRSA generation time is 3.5 hrs. To get the number of cfu calculated in the previoius question, how long has it been in hours from the time the 6 MRSA got into her bloodstream until she arrives at the emergency room?

Please show your work!!

Explanation / Answer

Part 1:

Number of MRSA CFU is 180 per mL of blood and the number of MRSA CFU in 3.5 L blood = 180 CFU/mL * 3500 mL = 630000 CFU (Since 3.5 L = 3500 mL)

Total CFU of MRSA in blood = 630000 CFU

Part 2: Use the follwing formula to calculate the time took to form 630000 CFU from 6 cells..

Nt=N02n (Where Nt: population at time 't'; N0: Initial population number; n: number of generations)

630000 = 6 * 2n

2n = 630000/6 = 105000 = 216.68

n = 16.68

number of generations (n)= Final time point/doubling time

16.68 number of generations = Final time point / 3.5hr

Final time point = 16.68 generations * 3.5 hr

Time took to form 105000 CFU from 6 MRSA cells with the doubling time of 3.5 hr = 58.38 hr

Related Questions

Navigate

• Browse (All)
• Browse M
• Subjects