Escherichia coli (E. coli) is a rod-shaped, gram negative bacteria that is part of the normal bacterial flora of the human intestine. These particular strains are not pathogenic, however other strains can cause food poisoning if consumed. E. coli’s entire genome has been sequenced and the genes it codes for are relatively well known.1 E. coli DNA is in the form of a plasmid which is circular DNA. Plasmids are easy to manipulate, self-replicating, stable, and applicable to various organisms due to a high integration potential. E. coli research is often used to study gene expression and has a high potential of being applicable to humans.2 For these reasons, E. coli is often used in research experiments. Ampicillin is a beta-lactam antibiotic
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coli will grow in the absence of Ampicillin, while there will be no growth in the presence of Ampicillin. E. coli with Ampicillin resistance (E. coli/pAMP) will grow whether Ampicillin is present or not. E. coli did not grow in the presence of Ampicillin because Ampicillin is an antibiotic that prevents the synthesis of the E. coli cell wall making it permeable to the surrounding environment causing lysis.1 Although growth was observed, the colonies in the quadrants were not isolated colonies or not genetically pure because they were not derived from a single cell due to improper streaking of four separate streaks/cultures. E. coli/pAMP did grow in the presence of Ampicillin because it contains plasmid pAMP, which has genes that code for proteins that prevent the antibiotic from interfering with cell wall formation.3 However, there was no growth in quadrant III most likely because the streak was too heavy (too many bacteria cells). The growth in quadrant IV can be attributed to accidental streaking from bacteria in Quadrant I. Isolated colonies were observed as tannish colored dots in the LB-AMP plate containing E. coli/pAMP. The growth observed in this instance is considered genetically pure because it is derived from a single E. coli cell that replicates clones to produce the colony. Using single parental colonies creates only genetically identical cells, therefore eliminating genetic differences as a factor affecting the results in experiments. Proper use of the streaking technique on the LB plates would most likely produce more accurate results in the form of isolated colonies where appropriate according to the hypothesis. No contamination (presence of any foreign growth other than E. coli) was observed, so the results confirm proficient use of aseptic techniques. The significance of these results shows the potential for bacterial infections where antibiotics will not be an effective
coli will grow in the absence of Ampicillin, while there will be no growth in the presence of Ampicillin. E. coli with Ampicillin resistance (E. coli/pAMP) will grow whether Ampicillin is present or not. E. coli did not grow in the presence of Ampicillin because Ampicillin is an antibiotic that prevents the synthesis of the E. coli cell wall making it permeable to the surrounding environment causing lysis.1 Although growth was observed, the colonies in the quadrants were not isolated colonies or not genetically pure because they were not derived from a single cell due to improper streaking of four separate streaks/cultures. E. coli/pAMP did grow in the presence of Ampicillin because it contains plasmid pAMP, which has genes that code for proteins that prevent the antibiotic from interfering with cell wall formation.3 However, there was no growth in quadrant III most likely because the streak was too heavy (too many bacteria cells). The growth in quadrant IV can be attributed to accidental streaking from bacteria in Quadrant I. Isolated colonies were observed as tannish colored dots in the LB-AMP plate containing E. coli/pAMP. The growth observed in this instance is considered genetically pure because it is derived from a single E. coli cell that replicates clones to produce the colony. Using single parental colonies creates only genetically identical cells, therefore eliminating genetic differences as a factor affecting the results in experiments. Proper use of the streaking technique on the LB plates would most likely produce more accurate results in the form of isolated colonies where appropriate according to the hypothesis. No contamination (presence of any foreign growth other than E. coli) was observed, so the results confirm proficient use of aseptic techniques. The significance of these results shows the potential for bacterial infections where antibiotics will not be an effective