MICB 201 Lecture Notes - Lecture 4: Polymyxin, Lactam, Autolysin
Document Summary
Archaea don"t cause illnesses in humans information we have regarding antibiotics only applies to bacteria. Deaths from infectious diseases has dramatically declined since 1900 b/c improved sanitation, sewage treatment, medical care, decrease in poverty + introduction of antibiotics. However, antibiotic-resistant bacteria spring up v fast after new ab development. 75% abs today = naturally synthesized by soil microbes (esp. Reason unclear, assumed to be for biological warfare but abs only effective at high concentrations unlikely to be reached in natural environments. Semi-synthetic = natural abs modified chemically, eg. -lactam abs derived from penicillin. At clinically-relevant (high) concentrations, antibiotics work by: Disrupting cellular process/structure unique to target organism, or. Disrupting cellular process/structure in targets without affecting same process in self. Eg. interfering w/ pg synthesis, translation, transcription, replication + membrane damage. New pg synthesis and effects of some abs, eg. -lactam. Bacterial cell must double all components in order to divide, including pg.
