Analysis

                    It is the tension  between creativity and skepticism that has produced the stunning and unexpected findings of science.     —Carl Sagan 

Home Abstract Background Question Hypothesis Objective/variable Material Procedure Results Analysis Discussion Sources of Error Conclusion Future Research Appendix Reference Acknowledgement

   

1.  Test for the inhibition curve of E.coli generated by ultrasound

Figure 1. Average bacterial growth of E. coli in 96-well plates after being sonicated and then incubated for 24hrs versus different time lengths of sonication (antibiotic was not applied) represented in a line graph. Data drawn from Table 1.

The preliminary test results for the inhibition curve of E. coli by ultrasound as demonstrated in figure 1 showed no decrease in the E. coli growth compared to the control in this specific time length (within 60min), contrary to what was expected. There may be an increase in E. coli growth as exposure time length to ultrasound increases, but the first point and the last point on the graph are within the error bars of each other, making it difficult to interpret if there is indeed an increasing trend. Note that none of the three main tests involved in this study was repeated, due to time restrictions.

 

2.   Test for MIC of spectinomycin to obtain a sub-inhibitory concentration

Figure 2. Average bacteria growth in 96-well plate after 24hrs of incubation with an application of spectinomycin versus different antibiotic concentrations (no sonication) presented in a line graph. Data drawn from Table 2.

When spectinomycin was applied at concentrations below 32μg/mL, E. coli growth gradually and evenly decreased as antibiotic concentration increased. At spectinomycin concentrations 32 μg/mL to 64μg/mL, there is an abrupt decrease in E. coli growth. Followed by a gradual decrease in E. coli growth when the concentration of spectinomycin was applied from 64μg/mL onwards. (See Fig.2) The MIC of spectinomycin is therefore 64μg/mL, and 32μg/mL will be used in the synergy test with ultrasound, so as to make certain that the bacteria is not inhibited by the antibiotic alone.

 

3.  Test for synergy between spectinomycin and ultrasound  

Figure 3. Average E. coli growth in 96-well plate 24hrs after being treated with spectinomycin and ultrasound versus different sonication time lengths, presented in a line graph. The spectinomycin concentration used was one deviation below the MIC, at 32μg/mL. Data drawn from Table 3.

In figure 3, there appears to be no significant decrease/increase in trend of the bacterial growth as sonication time increases – the bacterial growths at different sonication time lengths vary very slightly as compared to the control. The slight variation in the bacterial growth can be attributed to experimental errors.

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Enhancement of Antibiotic Action with an Application of Ultrasound
by Liz Meng: lizmeng10@hotmail.com
Victor Feng: haovictor_feng@hotmail.com
Sir Winston Churchill High School, Calgary.AB

01/05/2007