modifications to lecture on microbial control

CHEMOTHERAPEUTIC AGENTS

Monday, January 23, 2012

Antibiotics are medicines used to treat infections caused by bacteria only

Infections are usually caused by bacteria or viruses

Antibiotics, therefore, do not cure all infections

Many infections like the common cold, flu, mild sore throat or diarrhea are caused by viruses

CHEMOTHERAPEUTIC AGENTS


WHAT IF ANTIBIOTICS WERE USED INCORRECTLY?

No healing effect - If antibiotics are used for viral infections, there will be no effect on the illness

Antibiotic resistance - This occurs when one antibiotic no longer works on a specific type of bacteria

A stronger antibiotic will be needed to treat the infection caused by this resistant strain of bacteria


ANTIBIOTIC MECHANISMS


RESISTANCE


RESISTANCEMonday, January 23, 2012

Mechanisms of resistance

Hawkey, P. M BMJ 1998;317:657-660

Penicillins,Cephalosporins

Tetracycline

Streptococcus pneumoniae resistance to penicillins

MRSA penicillin binding protein

PBP2A

Imipenem resistant Pseudomonas aeruginosae


DO YOU CONTRIBUTE TO RESISTANCE?


Another factor that contributes to resistance is that when patients are prescribed antibiotics for a just cause, many do not finish their medication

This allows resistant bacteria to survive more easily

The practice of saving unused medication to treat themselves or others at a later date can also lead to resistant strains



Also contributing to antibiotic resistance is the widespread use of antibiotics to promote weight gain and to control disease in cattle, pigs, and chickens

Forty to fifty percent of antibiotics produced are used in livestock feed

This leads to an increase of resistant bacteria in these animals, which is then spread to humans



THE CONSEQUENCES OF RESISTANCE:Ecology of pathogenesis

Bacteria grow fast

High population densities

Great competition for resources

Pathogen = normal bacterium that has gained access to a new resource through new genes

--> Competitive advantage


12 Steps to Prevent Antimicrobial Resistance: Hospitalized Adults

1. Vaccinate2. Get the catheters out

3. Target the pathogen4. Access the experts

5. Practice antimicrobial control6. Use local data7. Treat infection, not

contamination8. Treat infection, not

colonization 9. Know when to say “no” to

vanco10. Stop treatment when infection

is cured or unlikely

11. Isolate the pathogen12. Contain the contagion

Diagnose and Treat Infection Effectively

Prevent InfectionUse Antimicrobials Wisely

Prevent Transmission

12 Steps to Prevent Antimicrobial Resistance: Hospitalized Adults


ANY QUESTIONS???


modifications to lecture on microbial control

Health & Medicine

mild sore

chemotherapeutic

illness antibiotic

treat infections

chemotherapeutic

antibiotic

stronger antibiotic

longer works