Aseptic Techniques for Bacterial Plates and Antibiotic Testing

This practical assignment involves the investigation of antimicrobial substances which are available on microbial growth. The aim of the experiment is to produce bacterial lawn through the use of multodisk antibiotic ring. The aseptic technique will be the major test which will be carried out. The technique helps to produce bacterial plates through the use of mast ring of antibiotics. The different anti-bacterial agents which will be used in this experiment include streptomycin, Sulphafurazole, Tetracycline, Ampicillin, Chloramphenicol, Erythromycin, Cefoxitin and Penicillin. The results from this experiment are able to align well with what US DHHS have been able to show on such experiments.

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ASEPTIC TECHNIQUES PRODUCING BACTERIALPLATES AND THE USE OF MAST
RING FOR ANTIBIOTIC TESTING
2. Introduction/ Theory
This practical assignment involves the investigation of antimicrobial substances which are
available on microbial growth. The aim of the experiment is to produce bacterial lawn through
the use of multodisk antibiotic ring (Wise 2006). The aseptic technique will be the major test
which will be carried out. The technique helps to produce bacterial plates through the use of mast
ring of antibiotics. The different anti-bacterial agents which will be used in this experiment
include streptomycin, Sulphafurazole, Tetracycline, Ampicillin, Chloramphenicol,
Erythromycin, Cefoxitin and Penicillin (Johnston, Gricar & Luke 2011). Different disks
containing the anti-bacterial will be tested through the aseptic technique. The grown zones are
known as inhibitions. In addition, the bacteria were observed under a microscope. The diameters
of the inhibition will be calculated and the area of the inhibition through the formula;
Area of zone = πr2
Nevertheless, some colonies may not grow, and they can be physically identified.
5. Results/Discussion
Antibiotic for mastring M14 Representation Antibiotic growth results
Ampicillin 10ug Gray AP Circule not formed
Cephalothin 5ug primrose KF Circule not formed
Colistin Sulphate 25ug white CO Small clear circle formed
Gentamicin 10ug Salmon GM Big clear circle formed
streptomycin 10ug white S Small clear circle formed
sulphatriad 200ug ST Circle formed but not clear
Tetracycline 25ug Brown T Big clear circule formed
cofrimazole 25ug white TS very little circule spot fromed

After carrying the experiment, circule spots are expected to appear. On most of the antibiotics,
the circule spots were able to appear. The growth of the colonies near the Multodisk arm is the
major expected result which is needed in the experiment. Among the eight antibiotics tested, two
of them did not have the spot on them, which are the Ampicillin and Cephalothin. The level of
growth of the circule spot was different on the different antibiotic used. The testing is able to
help the most effective antibiotic. Paper chromatography is the most effective method in finding
this kind of antibiotic. Nevertheless, Mastring has been an alternative method of testing of
antibiotics. Aseptic technique is used to help in keeping the experiments and things free from any
contamination (Sanders 2012). The development of the colonies is expected in the experiment.
Since six of the experiments were able to provide the expected, the results are reliable. The
failing antibiotic experiments can be attributed to presence of some contamination, which may
have affected the functionality of the antibiotics.
The results from this experiment are able to align well with what US DHHS have been able to
show on such experiments (US Department of Health and Human Services (DHHS) 2009). The
formation of colonies when different antibiotics are used is the main expectation on determining
the susceptibility of the antibiotics. The discrepancies may arise due to the differences in
temperatures and also the presence of contaminations. Nevertheless, their effects were low in this
experiment and this increased the validity of the results.
One of the major adverse effects of the presentation is confusion on the ring formation levels.
Different levels of rings are usually formed and it is usually difficult to differentiate their
formation. Control of contaminations must be controlled to ensure that correct results are
achieved.
6. Conclusion

In this lab experiment, the main lesson which I achieved was on the difference reactions of
different antibiotics. The aim of the reaction of the antibiotics was achieved when different
colonies were developed. The aseptic technique used was the main strength of the results
achieved. The major weakness was making sure that all the contaminations were treated. In
conclusion, different antibiotics are able to react differently and this helps to acquire the best
antibiotic for the given purpose. During the experiment, the tests developed colonies which will
grew near the multodisk arms. Moreover, the use of microscope in observation of the bacterial
formation was able to enhance the understanding of their distribution in the colonies. This part of
the experiment was carried and aimed and understanding the differences in the formation of the
colonies. The microscope observation was able to identify the differences in the intensity of the
colonies formed when different antibiotics were used. This helped in understanding the bacterial
formation and susceptibility.
7. Bibliography

Johnston, M., Gricar, J., & Luke, R. (2011). Sterile products and aseptic techniques for the
pharmacy technician. Upper Saddle River, N.J: Pearson.
Sanders, E. R. (2012). Aseptic Laboratory Techniques: Plating Methods. J. Vis. Exp. (63), e3064,
doi:10.3791/3064.
US Department of Health and Human Services (DHHS) (2009). Biosafety in Microbiological
And Biomedical Laboratories (BMBL). 5th, U.S. Government Printing Office. Washington DC.
Available from: http://www.cdc.gov/biosafety/publications/bmbl5/index.htm
Wise, K. (2006).Preparing Spread Plates Protocols. Available from:
http://www.microbelibrary.org/index.php/component/resource/laboratory-test/3085-preparing-
spread-plates-protocols