The Effect of Penicillin, Tetracycline, and Neomycin on Soil Microbe Resistance

Antimicrobial agents represent the greatest advance in modern curative medicine. These drugs are reckoned to have extended the life span of the average US citizen by 10 years, whereas curing all cancer would prolong life by 3 years. How much of a resistance can soil microbes develop when exposed to Tetracycline, Neomycin, and Penicillin? To test this question, we took soil from outside and put some into a test tube with distilled water. We then placed the tube into an incubator for a day. The next day, we flamed a metal loop and dipped it into the soil, then dipped it into several tubes with distilled water. After another day of incubation, the water was poured into Petri dishes that had 3 halves of one of the antibiotics. They were placed into the incubator for several generations. Every day, pictures were taken of the dishes. Using Print Shop Pro, the area of inhibition around each disk was found. An ANOVA statistical analysis was conducted. We received a p-value of almost zero, so we were able to accept our alternative hypothesis that the means of the samples were significantly different. Of the three antibiotics, the soil microbes were the most resistant to penicillin, which was completely resistant from the beginning of the trials. The least resistant was tetracycline. These results are important because the data shows how fast bacteria can become resistant to the antibiotics. Scientists can then take the data and determine if changes to the antibiotics can be made or they can start researching and developing possible new antibiotics.

Research Done By:

Thomas Gatchell
Center Line High School

Dillon Raxter
Center Line High School