Exercise 15: Antimicrobials
Kirsten Holtz MICR 202L November 09, 2016 Exercise 15: Antimicrobials
Purpose
The purpose of exercise 15 was to determine the effects of different antimicrobials on both Gram-positive bacteria and Gram-negative bacteria.
Procedure
Overall, exercise 15 was broken down into two days of procedures. For the first part of the experiment, we divided three petri plates into three equally sized units on the plate and marked them with wax pencils in accordance to which antimicrobial infused disk would be placed there. Following this, we aseptically poured the three plates with nutrient agar. Since we were assigned Micrococcus luteus, with some groups using Eschericia coli and Pseudomonas aeruginosa, for this …show more content…
coli and P. aeruginosa, had different results from M. luteus. We observed that there were some large zones of inhibition around some antimicrobials, like to water, bleach, Formalin, Polymyxin B, and Tetracycline, resulting in a sensitive result. There were multiple antimicrobials that also had small, resistant zones of inhibition for antimicrobials. It was observed that Scope and Penicillin both were very resistant when applied to plates with E. coli and P. aeruginosa.
Discussion
Due to the fact that M. luteus is a Gram-positive bacteria with no outer lipopolysaccharide membrane to protect it from the powers of antimicrobials, it was somewhat expected that there would be a result of sensitivity to most antimicrobial agents (2). This was concluded due to the large zones of inhibition, and essentially, the complete lack of any growth on the medium of the plates (2). In addition, it was also expected that E. coli and P. aeruginosa would be more resistant to antimicrobials due to their protective outer lipopolysaccharide membrane (2). This was clearly displayed in the results of the experiment.
Significance to daily
Purpose
The purpose of exercise 15 was to determine the effects of different antimicrobials on both Gram-positive bacteria and Gram-negative bacteria.
Procedure
Overall, exercise 15 was broken down into two days of procedures. For the first part of the experiment, we divided three petri plates into three equally sized units on the plate and marked them with wax pencils in accordance to which antimicrobial infused disk would be placed there. Following this, we aseptically poured the three plates with nutrient agar. Since we were assigned Micrococcus luteus, with some groups using Eschericia coli and Pseudomonas aeruginosa, for this …show more content…
coli and P. aeruginosa, had different results from M. luteus. We observed that there were some large zones of inhibition around some antimicrobials, like to water, bleach, Formalin, Polymyxin B, and Tetracycline, resulting in a sensitive result. There were multiple antimicrobials that also had small, resistant zones of inhibition for antimicrobials. It was observed that Scope and Penicillin both were very resistant when applied to plates with E. coli and P. aeruginosa.
Discussion
Due to the fact that M. luteus is a Gram-positive bacteria with no outer lipopolysaccharide membrane to protect it from the powers of antimicrobials, it was somewhat expected that there would be a result of sensitivity to most antimicrobial agents (2). This was concluded due to the large zones of inhibition, and essentially, the complete lack of any growth on the medium of the plates (2). In addition, it was also expected that E. coli and P. aeruginosa would be more resistant to antimicrobials due to their protective outer lipopolysaccharide membrane (2). This was clearly displayed in the results of the experiment.
Significance to daily