The level of contamination on the things we use on daily basis - Lab Report Example

The main objective of the experiment was to ascertain the level of contamination on the things we use on daily basis to make our face that include brush, Chap Stick and mascaras. This was achieved by morphological test. The following tests were done: For Morphological test; culturing was done. The samples were cultured on MacConkey and r2a plate. These three items were compared to determine the level of contamination. After 24 hours of growth on both MacConkey and r2a plate, small growth was observed in all the samples. Similarly after 48 hours, large colonies were observed on both media for samples brush and Chap Stick but this was relatively higher on the brush. After undertaking Gram staining, it was observed that all the samples on both media had Gram positive bacteria. According to the result findings, the most probable bacteria identified were all cocci, bacilli, and spirilla. Besides, the brush sample seems to have high levels of contamination. These tests have been explored in the next section. Introduction By definition, Cross contamination is the transfer or physical movement of bacteria that are harmful from one place, person or object to another. It is a major factor which contributes to food poisoning, and it consists of 4 common sources that include people, work surfaces, food and equipment. Harmful bacteria live in or can be on our bodies, particularly around or on hands and faces as well as on clothing (McKillip, 2011). Due to the fact that they exist in small numbers they never cause a disease. If it happens that, there is a transfer of these bacteria from the clothes or bodies to food, and then given a chance to multiply, it can lead to food becoming unsafe to be eaten. Bacteria have the ability to multiply and live in any crevices and cracks in equipment including the chopping boards surface cuts. After using the equipment, food bits with bacteria can remain. If there is no proper cleaning of the equipment, there will be transfer of bacteria to another food when it is used next. Surfaces including bench tops might have bacteria on them as a result of contact with people, also dirty equipment, raw foods or other things like cartons stored on the floor can contribute. If there is no proper cleaning of bench tops, there might be bacterial contamination of any food that is placed on them. The main objective of the study was to ascertain the level of cross-contamination on the thing we use on daily basis to make our faces that include brush, Chap Stick and mascaras. The experiment was conducted to test the amount of bacteria on the cosmetics we use daily. These products go to our face every time. Health is so critical and we need to give it a priority. The hypothesis of the experiment was that the brush had the highest level of contamination followed by Chap Stick then mascaras. Materials and methods Petri dishes Mascaras Brushes Chap sticks Method To begin the experiment there was a collection of the variety of cosmetics that included State brand and type od make up used. The next step was culturing as presented below; Culturing Techniques Incubation was done on agar media at of 37 oc . Streaked specimen using a loop, later flaming and cooling was done, then streaked at 45o for a second time, this second streak over­lap­ped the first one.. There was less growth after 24 hours then after 24 hours a lot of growth was observed on both agar plate that was observed at 37 oc. There were large colonies, white in color, pink colonies, red colonies, circular in form, with margin that was filamentous Procedure for Tube method Five drops of 3% H2O2 was added to a 12 x 75-mm test tube. Small organism amount was collected with a wooden applicator stick from a ‘’well-isolated 18- to 24-hour colony’’ then it was put into the test tube. Care was taken not to pick up any agar. This is particularly crucial if the isolate of the colony was grown on agar that had red blood cells. The tube was Placed against a dark background and formation of immediate bubble was observed (O2 + water = bubbles) at the wooden applicator stick end. Immediate effervescence is an indication of Positive reactions (bubble formation). A magnifying glass was used instead of microscope in observing weak positive reactions. No formation of bubble (no Catalase enzyme to hydrolyze the hydrogen peroxide) indicates a reaction that is Catalase-negative. Quality control was performed using organisms that were known to be negative and positive for Catalase. Data Analysis Culturing Results After 24 hours of growth on both MacConkey and r2a plate, small growth was observed in all the samples as shown in figure 1and 2. Similarly after 48 hours, large colonies were observed on both media for samples brush and Chap Stick (fig 3) but this was relatively higher on the brush as shown in figure 4. Figure 1: small growth on MacConkey (24hrs) Figure 2: Small growth on R2A Plate (24hrs) Figure 3: large colonies on MacConkey (48hrs) Figure 4: large colonies onR2A Plate (48 hrs) Biochemical Results According to the results of Catalase test it was observed to be positive on some colonies but negative on others. The isolate of the colony was grown on agar that had red blood cells. The tube was Placed against a dark background and formation of bubble was observed (O2 + water = bubbles) at the wooden applicator stick end as shown in figure 5.Immediate effervescence indicated Positive reactions (bubble formation)as shown in figure 5. No formation of bubble (no Catalase enzyme to hydrolyze the hydrogen peroxide) indicates a reaction that is Catalase-negative (Fig. 6)(Negative control) Conclusion There is no way one can avoid bacteria because they are everywhere and can be transferred from one place to another, thus, cross contamination. The brush was the one with the highest level of bacterial contamination followed by Chap Stick then mascaras. This is because it is made of hairs, hence, more prone to bacterial growth. It is seen that brushes consist of synthetic or animal hair. They are supposed to be kept clean always to avoid this kind of bacterial growth. For the Chap Stick, if they are not covered properly, bacterial growth can take place due to the available moisture on them. They are in a way that they can’t permit bacterial growth and they normally go to the mouth directly. They are used by people to prevent chaps lips therefore they are supposed to be kept very clean. Mascaras being the last on the list with fewer colonies, it is a material that is well preserved and does not lead to bacterial growth. It is made from asphalt that consists of very tough materials. Works Cited Abedon, Stephen T "Supplemental Lecture: Bacterial Cell Shapes and Arrangements."March 28,. http://mansfield.osu.edu/~sabedon/biol2010.htm.2011.Print South Bend Medical Foundation. Catalase test protocol. South Bend Medical Foundation, South Bend, IN.2010.Print Mahon, C. R., D. C. Lehman, and G. ManuselisTextbook of diagnostic microbiology, 4th ed. W. B Saunders Co., Philadelphia, PA. 2011. Print Wheelis, M, Principles of modern microbiology. Jones & Bartlett Publishers, Inc., Sudbury, MA. 2008.Print Read More