Observation Of Bacteria On Chicken And Handrail And The Effect Of Germx® And Alcohol On Them.

Observation of Bacteria on Chicken and Handrail and the Effect of GermX® and Alcohol on Them.

Sujit Bhimireddy, Daryl Onwuchuruba, Naveen Sood, and Manasa Tripuraneni

Biology 106

Abstract

Bacteria are found everywhere on this planet. This experiment is aimed at observing some of the bacteria that surround us in places that we use everyday. We will look at bacteria found on a piece of chicken and bacteria found on a handrail. The effectiveness of antibacterial substances such as GermX® and alcohol will be studied. Paper discs dipped in GermX® and alcohol will be placed on the plate and the zone of inhibition will be measured in order to compare with the control.

Introduction

In this scientific study our group is conducting a study in order to see what type of bacteria would grow in two different environments and compare the environments in terms of bacterial growth. Our assigned environment was a piece of chicken. A study done by Dr. Norberg in 1981 showed that although the poultry business does a very effective job at disinfecting the chicken of salmonella, some other bacteria such as Yersinia enterocolitica are over-looked. Y. enterocolitica can survive cold temperature and can grow on the chicken while it is being refrigerated. Y. enterocolitica is pathogenic to humans (Brooks 2005). It is important to understand the different types of bacteria that are found on chicken because it is consumed as food and could affect the health of many people. This has great implications on the food industry.

For the environment of our choice we choose a handrail. The study conducted by Reynolds et. al on public surfaces like handrails indicated that fecal coliforms are prevalent (Reynolds 2005). This study is important because numerous people come in contact with these surfaces everyday. This study emphasizes the importance of practicing good sanitary measures such as washing hands regularly. E. coli is an example of a coliform bacteria.

In our experimental plates we will test the effectiveness of GermX® and alcohol. The effectiveness of each substance will be measured by looking at the zone of inhibition around paper discs that have been dipped in either GermX® or alcohol.

Ha1: Plates treated with GermX® will have larger zones of inhibition than plates treated with alcohol.

Ha2: Plates treated with alcohol will have larger zones of inhibition than plates treated with GermX®.

H0: There will be no difference between the plates treated with GermX® or alcohol.

Methods

We began the experiment by swabbing a chicken and a handrail by the stairwell exit near room 10 in Maclewane Hall in Saint Louis University. We streaked the swabs on agar plates using the technique described on page 88 from morgan and carter 2005. One plate was used to grow the culture from the chicken and two plates were used to grow the culture from the handrail. Circular paper discs were dipped in alcohol and GermX® and three of each were placed on plates with culture from the handrail. The culture from chicken was not exposed to anything. The cultures were allowed to grow for one week and then observed. We observed various physical properties of the cultures such as the size, shape, margin, color, and surface texture of the colonies. The size f the colony was determined using a ruler. We also observed the shape of the bacteria under a microscope and whether it is gram-negative or gram-positive. In order to tell whether the bacteria are gram-negative or gram-positive, we performed a gram-staining procedure as described in Morgan and Carter 2005. We also measured the zone of inhibition around the paper discs dipped in alcohol and GermX® in order to see which was more effective.

Results

All the colonies that grew from the chicken were white in color and the average size of each single colony was 4 mm in diameter. The margin and the surface texture of the colonies appeared to be smooth. The colonies were round. This plate was not treated with any substances that would inhibit the growth of the colonies. The gram-staining showed that the bacteria was gram-negative and microscopic observations showed that the bacteria was a cocci.

Most of the colonies found on one of the plates with culture from handrails were white but a few were yellow. The average size for both the white and yellow colonies was 2 mm in diameter. The margins for the yellow colonies in both the plates were curled. The surface of the yellow