Lecture 26B Flashcards
why is tuberculosis a reemerging infectious disease?
- difficult to kill off and requires long periods of antibiotic treatment
- people stop taking antibiotics before infection is cleared
- immune compromised people are at particular risk
- natural history of the disease is also challenging here
frequency of spontaneous mutation,conferring resistance to
rifampin (RMP): 1 in 10^10
- ethambutol (EMB): 1 in 10^7
- pyrazinamide (PZA): 1 in 10?
_ isoniazid (INH): 1 in 10^8
What’s the frequency of tuberculosis cells in a patient with the pulmonary TB
10^12
combination therapt
Takes for antibiotics with different resistant mechanisms for two months
solo therapy(latent tb)
One antibiotic sometimes two for 6 to 12 months
what contributes the antibiotic resistance
Overuse of antibiotics in:
food
livestock
unnecessary prescriptions
pathogens (and resistant genes) move between
humans and livestock
what does horizontal gene transfer mean for antibiotic resistance genes?
can move between different species of bacteria, pretty easily
DNA transferred by conjugation
DNA from a donor cell is transferred through a pilus into the recipient cell
dna transfer by transformation
DNA released into the environment by dead cells is taken up by recipient cell
DNA transfer by transduction
DNA is transferred from a donor to a recipient cell by a virus
How does antibiotic resistance spread so fast?
fast reproduction
High mutation rate
Horizontal gene transfer
Strong selection pressure
What does not taking a full course of antibiotics lead to
Evolution of resistance
Taking a full course of antibiotics, actually increases selection for
resistance
How can we slow the spread of antibiotic resistance?
use antibiotics only for bacterial infections
Cycle antibiotics in hospitals
Don’t use antibiotics or antimicrobials in meat reproduction
