BIO2440 - Lab Report 1 PDF

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Summary

LAb report 1 for BIO 2440 lab...

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Glo-Germ, Aseptic Techniques, & Ubiquity of Microorganisms

Introduction

The first experiment conducted was Glo-Germ. The purpose of this demonstration was to show the importance of washing hands properly. Glo-Germ is a solution that exposes bacteria not yet exterminated when a UV light shines on it. Students will wash their hands prior to applying the Glo-Germ, then will have skin to skin contact with another (through high fiving, shaking hands, fist bumping, etcetera). The students’ hands are then exposed to the UV light to see the bacteria. Students are then ordered to wash their hands again prior to the second screening to the UV light to attest their hand washing techniques.

The Aseptic Techniques experiment was to understand the proper demonstration of the inoculation technique and get results for an aseptic transfer. In order to conduct this experiment, students were given an inoculation loop, a TSA plate to swatch Staphylococcus aureus and S.marcescens. The inoculation loop was firstly sterilized by fire before cooling down to take a sample of the Staphylococcus aureus. The student then smeared the sample onto one half of the agar plate, then proceeded to do the same with the S.marcescens to spread on the other half of the plate. The petri dish was then incubated at thirty-seven degrees Celsius for twenty-four hours.

The last experiment, Ubiquity of Microorganisms, was to demonstrate how bacteria transfers from many places and how without exterminating the bacteria, thus affecting other’s

health. Every pair of students were given two TSA plates and a cotton swab. The tip of the cotton swab was cleaned with DI water before collecting bacteria. The pair were to swatch the cotton swab onto the surface of the agar plate gently. The petri dishes were then incubated at thirtyseven degrees Celsius for twenty-four hours. The control variable for this experiment was the air, as there was a separate petri dish specifically just to collect what was in the air for around ten minutes.

Results

Figure 1: Right side is a sample of Staphylococcus aureus. Left side is a sample of S.marcescens. Incubated at 37 degrees Celsius for 24 hours.

Figure 2: Sample of the air incubated at 37 degrees Celsius for 24 hours.

Figure 3: Sample from a phone incubated at 37 degrees Celsius for 24 hours.

Figure 4: Sample from the bottom of a shoe incubated at 37 degrees Celsius for 24 hours.

Figure 5: Sample from soil incubated at 37 degrees Celsius for 24 hours.

Discussion

Experiment number one, Glo-Germ, showed that out of all the ways students had skin to skin contact, high fiving transferred the least amount of bacteria in comparison to fist bumping and handshaking. This would be due to high fiving requiring the least amount of time to do, whereas fist bumping and handshaking require more time to accomplish. With the longer time of just a few seconds, this gives bacteria a better opportunity to transfer from one surface to another.

Experiment results for number two, Aseptic Technique, were anticlimactic. However,

there is a fault in this experiment due to the petri dish being open for about a minute before the bacteria were swabbed on the dish. In order to prevent this mistake from happening, the petri dish lid must be closed at all time until the moment before swabbing the bacteria onto the agar.

Experiment number three, Ubiquity of Microorganisms, showed how much bacteria were on an individual's objects. With the air sample (Figure 2) as the control compared to the phone (Figure 3) and shoe sample (Figure 4), there was plenty of difference in bacterial growth. The phone, surprisingly, did not have much bacteria as would’ve been expected personally. Whereas the shoe sample made sense due to going to different places and walking, the bacteria were sure to collect at the bottom of the shoe. Figure 5, the soil sample, is also full of bacterial colonies.

These experiments presented the importance of just how fast and easy it is for bacteria to spread and grow on surfaces. Thus learning how to properly wash hands with soap and water will prevent transferring bacteria. If not, individuals are exposed to infections such as Hepatitis A, a viral infection that is contracted by food contaminated by those who did not wash their hands after using the restroom. Washing hands with soap and water eliminates a strain of Hepatitis A Virus (HAV), HM-175 (JN Mbithi 1993). This study shows the effects that happen to those who do not wash their hands with soap and water, justifying the importance of washing hands in order to prevent the transfer of bacteria. Hand hygiene is practiced daily in the medical field, as it reduces cross-transmission of infections from working patient to patient in the field. Factors that play into effective hand washing are hand washing agents, hand rubs, and frequency (Mathur 2011). Bacteria is everywhere and it is almost impossible to eliminate all of it, however hand washing properly will reduce the risk of transmitting bacteria from and to surfaces.

References

Mathur, P. (2011, November). Hand hygiene: Back to the basics of infection control. US National Library of Medicine National Institutes of Health.

Mbithi, J., Springthorpe, V., & Sattar, S. (1993, October). Comparative in vivo efficiencies of hand-washing agents against hepatitis A virus (HM-175) and poliovirus type 1 (Sabin). US National Library of Medicine National Institutes of Health....