You are a health-care professional involved in the treatment of an elderly patie
ID: 189798 • Letter: Y
Question
You are a health-care professional involved in the treatment of an elderly patient receiving outpatient hemodialysis through a central vascular catheter. During preparation for hemodialysis treatment on a particularly hectic day, you skip a step in your facility’s hand hygiene protocol and are not careful while putting on your gloves. Just a few cells of a Psuedomonas aeruginosa strain are wiped from your hand onto the outside of your glove and are then deposited at the edge of the patient’s catheter. Just 5 of these cells are pushed further into the catheter, adhere to the plastic and start dividing. The patient finishes hemodialysis treatment and goes home. The generation time of this P aeruginosa strain growing as a biofilm on the catheter, under these conditions is 5 hours.
In the hospital, the patient is started on treatment with intravenous cefoperazone. Cefoperazone is a third generation cephalosporin derivative. Cephalosporins are beta-lactam antibiotics, which are considered most effective against gram-positive organisms, but 3rd generation cephaosporins are also effective against gram-negative organisms. Cefoperazone is one of the few 3rd generation cephalosporins with "anti-pseudomonal" coverahe, meaning it is effectice against some strains of Pseudomonas.
5) with what general bacterial process do beta-lactam antibiotics interfere?
6) with what specific activity(ies) in the process you chose in question 5 do beta-lactam antibiotics interfere?
With this treatment, the growth rate of the P. aeruginosa is slowed to a generation time of 35 hours. From the total number of bacteria in the patient’s blood at the time she arrived at the hospital, which you calculated above in question.
7) what would the total number of bacteria in her blood be after 6 days in the hospital?
Explanation / Answer
5. The beta lactatm antibiotics acts by inhibiting bio synthesis of bacterial cell wall.
6. Beta lactatm antibiotics specifically target penicillin binding proteins (PBPs), a group of enzymes found anchored in the cell membrane, which are involved in the cross linking of bacterial cell wall. The beta lactatm ring group of these antibiotics will bind to different PBPs rendering them unable to perform their role in cell wall synthesis. This leads to death of bacterial cell due to osmotic instability or autolysis.
7. 6 days means 6 x 24 hours=144 hours. Generation time 35 hours i.e 2 power 4 (2x2x2x2)=16 cells.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.