Abstract
Infections have been the main source of disease throughout the history of human populations. It was thought that with the introduction of antibiotics that this problem would vanish. However, bacteria have been capable to evolve to become antibiotic resistant. Bacteria that acquire this appearance are much more harmful because the fight of contagions become harder to surmount. An understanding of where resistant bacteria reside is needed in order to recognize their most favorable emergent settings. My research started by swabbing numerous public locations on the campus of Michigan State University such as a trash compactor, sewer plates and a weight room. These places were chosen because microorganisms are so common that they can be located everywhere. A diversity of locations was sought after as well. The bacteria were then cultured on agar plates containing three diverse antibiotics: ampicillin, kanamycin and tetracycline. Amplification of single colonies was obtained by placing them in LB broth in order for obtainment of discrete plasmids through lysis. The plasmids were cut with restriction enzymes and gel electrophoresis was performed in order to help categorize the plasmids. Places that obtained the most resistant bacteria were desired because when antibiotics are used; it endorses the development of antibiotic-resistant bacteria (Anonymous-1, 2005).
Discussion
Given that bacteria are everywhere, a prediction was made that bacteria would be available at all the locations that were swabbed. Bacteria was indeed found at eleven of the twelve sites, which was indicated by the fogginess in the tubes that contained the LB broth and q-tip swabs of the bacteria locations. Uncertainty came into play as of why no bacteria grew from the swab of the mouth. Big Redã gum was being chewed prior to the swab, and it has been found that cinnamon flavored gum shows a strong antibacterial effect in the mouth and even opposes bad breath, (Adams ,2005) however I don’t believe that due to the gum all the bacteria would have been destroyed, possible a mouthwash was used by the gum chewer on a daily routine which could possibly help eliminate most of the bacteria and that there would be none visual when the swab took place. The sites that were chosen were due to an expectation to be able to find resistant bacteria to the varied antibiotics used. Locations that were often cleaned took an important role in the decision-making because; this increased the chances of bacteria becoming antibiotic resistant if they were consistently exposed to them. Every bacterial site that grew in the LB broth was resistant to the antibiotic ampicilin; there were only eight locations that grew in the kanamycin, and four sites that the bacteria grew in tetracycline. If bacteria dies in antibiotics it is said not to contain resistant qualities. This would explain why the bacteria grew in certain antibiotics. Each resistant bacteria contains a plasmid that confers the capability to be antibiotic resistant (Krha, 2005). Then the transfer of the bacteria from the tubes to LB agar plates took place. A plate was made for every site that had antibiotic-resistant bacteria. Sites were assigned to each lab group member by way of deciding which four had the most and best bacteria formed. My location was kanamycin -compactor room. The addition of the bacteria to a plate containing the same antibiotic that was in the LB broth in the tube did not hinder growth since it had already been verified that the bacteria became antibiotic resistant to it. Isolation of individual colonies of bacteria was done by the previous step and was the main purpose of bacteria on the agar plates. After harvesting the cells to acquire an isolated colony, lysis was performed to obtain the plasmid found in each bacterium. Lysis denatures the chromosomal and plasmid DNA threads, and then tries to put the pieces back together. Due to the fact that the chromosomal DNA is composed of millions of base pairs, it won’t renature in the right order. The plasmid DNA is greatly smaller and consequently the renaturing procedure is more successful (Krha, 2005). Gel electrophoresis is used to establish approximately how many base pairs are in each DNA piece. The buffer solution that enclosed the DNA was put into the wells near the cathode, which has a negative charge. Since DNA is negatively charged, when the current goes through the gel, the DNA will travel away from the cathode towards the anode at the base of the gel plate because; the positively charged anode attracts negative charges. The smaller pieces will travel farther due to they are not slowed down as much as the larger fragments are when traveling through the gel. The addition of diverse restriction enzymes cut the plasmid into fragments and the results of the cut could not be seen until gel electrophoresis was run. However, due to circumstances beyond my control, no cuts were seen on the gel except for the lambda ladder. The lambda ladder was used to compare the base-pair length of the unknown plasmid pieces to the base-pair length of known DNA pieces. A possibility of why no bands showed up could be due to the fact that the enzymes could have cut the plasmid DNA so extremely small that the fragments could not be seen. The further procedures could not be performed because the enzymes did not cut the plasmid DNA and calculations could not be taken in order for possible identification to occur. Possibilities of why the research was not a success could be numerous things. The restriction digest could have been tainted with by not applying the appropriate concentrations to the DNA and it could’ve messed up the rest of the experiment. These several procedures were to help determine what plasmids are found in the antibiotic-resistant bacteria obtained from various places on Michigan State’s campus .
Figure 5: LB Agar Plate with Antibiotics and “Pox Growth” of Bacteria.
