Against the odds, this combination treatment begins to work. The growth of the b
ID: 190641 • Letter: A
Question
Against the odds, this combination treatment begins to work. The growth of the bacteria in the blood is completely arrested. Also, since colistin has bacteriocidal activity, it begins to kill the bacteria.
If the bacteria reached a peak of 900 cfu/mL in her blood and the death rate is 60% per day,
11) How many days of uninterrupted tigecycline and colistin treatment would it take for the infection to clear? (Assume that growth is completely arrested.)
The patient recovers, but has permanent kidney damage from the prolonged colistin treatment. Many hospital-acquired infections are caused by the normal flora of healthcare workers that infect immunocompromised patients or are introduced to sterile equipment through lapses in hand hygiene protocol and aseptic technique.
12) How do you think healthcare facilities should enforce these protocols and deal with lapses?
Explanation / Answer
11) As bacterial growth is completely arrested. and bacteria is dying at the death rate of 60% per day
so we have, initial bacterial colony number, No= 900cfu/ml r=60% per day or 0.6/day And final bacterial colony number, N= 1cfu/ml (we cannot take final bacterial colony number as 0 due to fact that natural log of 0 tends to infinity)
Now form bacterial death equation
dN/dt = -rN ---- negative sign indicate the death phase
if we solve above equation we will get
ln(N/No) =-rt-----(2)
putting all value in equation 2 we will get
t= 11.33 day
that means 11 days of uninterrupted tigecycline and colistin treatment would it take for the infection to clear