2/10/2016 Mechanisms of Resistance Persister-involves a 1.Destruction or inactivation of the drug by metabolic shutdown enzymes not a genetic mutation .Beta-lactamases breakdown penicillin-like drugs 2.Prevention of penetration to the target site within the microbe .Gram-negative porins are altered 3.Alteration of the drug's target site Antibiotic resistance tests .mutations affect drug interaction but not function of the target che lasses-Left most image 4.Rapid efflux (ejection)of the antibiotic 5.Variations of mechanisms of resistance Example mechanisms of antibiotic resistance Rapid development of an antibiotic-resistant 4 2 mutant during antibiotic therapy Antibiotic resistance of bacterial 1 Efux pump Decreased uptak biatic eeded to c 50 40 20 0000C0000MPw4 5 3 7B9011 52/10/2016 5 Persister - involves a metabolic shutdown not a genetic mutation A tibi ti i t t t Antibiotic resistance tests Superbugs – resistant to most antibiotic chemical classes – Left most image Mechanisms of Resistance 1. Destruction or inactivation of the drug by enzymes • Beta-lactamases breakdown penicillin-like drugs 2. Prevention of penetration to the target site within the microbe • Gram-negative porins are altered 3. Alteration of the drug's target site • mutations affect drug interaction but not function of the target 4. Rapid efflux (ejection) of the antibiotic 5. Variations of mechanisms of resistance Example mechanisms of antibiotic resistance Rapid development of an antibiotic-resistant mutant during antibiotic therapy Initiation of antibiotic therapy Antibiotic resistance of bacterial population measured by amount of antibiotic needed to control growth Bacteria count