The Kirby-Bauer Test

Since bacteria alter in size, structure, shape, and susceptibility to antibiotics, healthful chemicals differ in their potence and spectrum of activity. Scientists and doctors needed a track to goodly identify types of pathogens in patients, so they could administer a drug that would specifically fag the organisms. Kirby-Bauer test, alike known as the turn-diffusion method, is the most widely employ way of testing healthful substances. The tellingness of a certain(p) chem another(prenominal)apeutic component is contumacious by the size of a regulate of inhibition on an inoculated nutrient agar plate. A zone of inhibition is the area where a filter paper disk soaked with an healthful mover placed on the agar surface inhibits growth of inoculated microorganisms. establish on the size of a zone of inhibition and the parity to a specific chemotherapeutic agent employ, organisms are categorize as sensitive, intermediate, or resistant. We depart find out which chemoth erapeutic agents are most effective against which organisms. My initial hypothesis was that confirming bacteria such as Staphylococcus aureus would be allergic to many chemical agents used in the lab, since they lack an satellite membrane that protects the peptidoglycan cell wall. Whereas negative bacteria such as Escherichia coli or Pseudomonas aeruginosa would be more resistant than Gram-positive bacteria because they have an satellite(prenominal) cell membrane. However, I also hypothesized that polymyxin B might not be as effective to g positive S.aureus as other chemical agents, because since this agent was typically to bind to lipoid A in the outer cell membrane of Gram-negative bacteria, polymyxin B would not be able to penetrate the summary peptidoglycan layer of S. aureus. Also, we will be able to infer the gram stain of my groups unknown organism based on the kindred between its sensitivity to other known organisms sensitivities to different antimicrobial agents.\ nOur group obtained four small...