Final Report 1: Bathroom Bacteria Battle

This topic submitted by Lauren Davis, Dan Pierce, Brad Price, and Audrey Savin ( at 3:07 PM on 12/5/02. Additions were last made on Wednesday, May 7, 2014. Section: Negron-Ortiz

Natural Systems 1 Fall, 2002 -Western Program-Miami University

Lauren Davis
Dan Pierce
Brad Price
Audrey Savin

Student Generated Lab
Bathroom Bacteria Battle


The Bathroom Bacteria Battle hopes to concretely prove which of the sexes have cleaner bathrooms. We believe that the maleÕs bathroom will have less bacteria in it because of the fact that females use the bathrooms more often, therefore leaving more germs behind each time they use it.

To come up with an idea for our student generated lab, we first thought about studying topics that immediately affect us as college students here on the Western Campus. Bouncing back ideas from water purity to Alexander Dining Hall food, we finally came up with the idea of the cleanliness of our bathrooms. We assume that they are nice and clean yet we will find out for sure. Most bacteria are harmful for our bodies but not all. More than just dirt hanging around the bathroom is unhealthy and that is why we are determined to focus our investigation on bacteria in our bathrooms.

In our lab we plan to successfully find the level of bacteria in the bathrooms. If necessary, we will raise awareness of the bacteria levels so people will take more caution when using the bathrooms. We will contact campus health inspectors if the level is too high, and expect them to act on our findings. If we find in our investigation the level is dangerously high we hope it will bring immediate change in our cleaning processes within the bathrooms.

To the residents of Peabody Hall, our research will be important. Bathrooms are a place where one goes to clean themselves, but if the bathrooms are not clean the resident cannot be clean. Every person that enters the bathroom makes skin contact with places in the bathroom. With each contact there is a greater level of bacteria buildup. We hope that when the bathrooms get cleaned the bacteria is washed away. The accumulated bacteria are not healthy for the residents of Peabody Hall and our experiment will make the residents aware of the bacteria level. Once we have the residents aware of the bacteria level the residents can do what they wish with the information.

Also, learning more about bacteria in the bathrooms will help each of us better to clean our own bathrooms later on in life. We will know the locations in the bathroom that bacteria grow the bet. Our family will be healthier because there would be a lower level of bacteria. Everyone in a house has to use the bathroom and if it is bacteria free there will be less chance of sickness. With less chance of sickness come more smiley faces in the household.

This research is interesting because we will be learning about the bacteria that we come in contact with every day. This topic concerns everyone. Bacteria are a threat to health, and if we find the levels are too high people will be interested in knowing. Health is a large concern this day in age and anything we can do to promote healthier environments is beneficial.

Relevance of the Research Question

A number of studies relating to the sanitation of bathrooms have already been
executed. No doubt it has been a major concern to other scientists in the past. It is necessary to do background research in order to become oriented with the relevance of the study we are performing, what new issues we can address, and how we can use existing information to support our own.

In 2000, Baker and Bloomfield studied the presence of Salmonella in domestic bathrooms. Despite the fact that Salmonella is usually contracted by consumption of contaminated food, this study shows that the bacteria commonly spreads by air and physical contact in 4 out of 6 households. It is difficult to remove the bacteria with common household cleaners. This is because it can get embedded into the biofilm on the underside of the toilet bowl and just below the water level (Barker and Bloomfield, 2000). In fact, according to one study, use of ammonia-based detergent promoted the growth of bacteria colonies. This is because of the nitrogen contained in these products. In addition, because the detergent being used becomes contaminated, it spreads the bacteria to new surfaces as the individual continues to ŅcleanÓ other areas (Dharan et. al. , 1999).
The levels of bacteria in cold water and hot water were compared in another study. The cold water contained a higher amount of mesophilic bacteria and fungi. Therefore, one might think that where hot water is used it will contain a smaller amount of bacteria than other parts of the bathroom. However, the decrease in the hot water temperatures coming from a showerhead and the cooling of the standing water could promote increase of microbial organisms (Zacheus & Martikainen, 1995).

Everyone expects that there is bacteria growth on bathroom surfaces. However, the magnitude of bacteria found in bathrooms, used so frequently and by as many people that live in Peabody Hall, will be alarming. Even though our immune systems can resist these common bacteria, such high exposure could pose a threat to the health of the students here. One common bacterium is Streptococcus pyogenes and is found in the throats of healthy people. This bacterium can be transmitted by air or saliva. However, it can cause diseases such as pharyngitis, impetigo, meningitis, and toxic shock syndrome (Wilson, Mc Nab, Henderson, 2002). Staphylococcus, E. coli, and many other normal microflora can be spread among the students potentially causing major problems.

It is extremely difficult to create an environment completely hostile to all bacteria in order to prevent our infection. Bacteria can evolve and adapt. They can live and grow under a wider range of oxygen levels (Gillies and Dodds, 1976). Nevertheless, it is important to eliminate as much of the pathogenic bacteria as possible by using careful cleaning procedures. When a certain bacteria evolves into an extremely dangerous form or there is an infection that spreads among students grouped in such close quarters - sharing the same fountains, the same toilets, and the same showers Š the entire community can be infected. This project will make other people aware of the real possible threat of using community restrooms and showers. Even if the presence of harmful bacteria cannot be eradicated, students can take precautions to protect themselves from infection on their own.

Methods and Materials

The materials we need for our experiment include: cotton swabs, twenty-four Petri dishes with Agar, microscopes for analysis of bacteria samples, labels for Petri dishes, tapes, camera for pictures.

Prior to our collection of data, we prepared the Petri dishes filled with Agar. Agar is prepared from Bacto-Agar. It was mixed into a 1% solution with distilled water. The solution is clear, once boiled. The other half of the Petri dish will be filled with another type of Agar specifically made to grow bathroom bacteria. We poured the Agar solutions into each half of the Petri dishes and allowed them to cool naturally for twenty-four hours.
We took samples of bacteria with a cotton swab from six given locations in each bathroom tested. We took the samples from, the entrance door handle, stall door handle, the urinal, the toilet seat, the shower floors, and the faucet handles. For each of these locations we took two samples. To take these samples we scratched the surface with a sterilized needle. Immediately after we slightly opened the Petri dish in order to slide the cotton swabs quickly across the Agar surface. Then we securely closed the Petri dish and labeled it for later observation. We used a new cotton swab and repeated these steps to obtain the rest of the samples. Once all of the samples are collected we kept them in a safe and stable location for the cultures to grow. Every Monday and Thursday after we returned to the samples to make observations about the bacteria, its growth and composition.

To measure the bacteria in our samples we observed them and did our best to accurately describe and document what growths were present. In order to help us determine which types of bacteria are present we will document the color of the growth in the Petri dish.
Our experiment is statistically sound because we are using universal measurements to count determinable amounts. Our experiment is also statistically sound because our collection and measurement methods are consistent throughout the entire experiment. Advice to make our research more substantial came from our teaching assistants who pushed us to think of how we would accurately measure the amount of bacteria.

There are many specific procedures that need to occur to ensure our accuracy of results. Specifically, we determined that we must only slightly open the Petri dish to swab the Agar with the needle. This must be done to ensure no other contamination occurs within the Petri dish from outside elements. Also, we determined that the cotton swab needed to be changed for each sample in order to keep them uncontaminated. Lastly, during the observation process we decided that only one person could be accountable for each variable so human error is minimized. We realized different people make different observations so we eliminated this potential problem from our lab.

Although we will be using our best judgement when collecting and observing our data human error will always be present. Due to human limitations of observation we will not be able to avoid an unbiased result. Our experiment will biased but only indirectly through human error. In order to keep these unbiased results to a minimum we designed certain tasks for each person in the group to do.

Instead of having the class collect the physical data, we had the students observe the grown bacteria under the microscope in order to help us identify the specific bacteria present. Our data collection would be thrown off if it were given to a large group of people to observe, due to inconsistency. We hope with other groups trusting us to collect their data, they will in return, provide accurate results for our lab. We demonstrated specifically how to collect the data, which will again minimize inconsistency.
In our study, the class used the microscopes in order to help identify specific bacteria growths. We will assigned 4 Petri dishes to each group of three or four students with one of our lab members assisting. We provided photocopies and examples of what they are looking for. This eliminated confusion on the behalf of the observer and allow us to maintain a constant data collection. Using the class for this part of the experiment allowed for mass data collection within a shorter amount of time, while ensuring accuracy. The class only had to report the type of bacteria found in their Petri dishes to us.

On Sunday, November 3rd, we went into the bathrooms and collected our bacteria samples for each Petri dish. We then observed our samples each Monday and Thursday for the next three weeks. On November 21st, we came before class for our final observations. Once class began we proceeded to lead the class in the microscope investigation of the bacteria types in the Petri dishes. Before the end of class, our data collection was complete. On December 4th we posted our final lab report. This will include our introduction, all of our observations and our data tables.

Sample # Gender of Bathroom Location in Bathroom
1 female outside door
2 female outside door
3 female stall door
4 female stall door
5 female urinal
6 female urinal
7 female toliet
8 female toliet
9 female faucet
10 female faucet
11 female shower
12 female shower
13 male outside door
14 male outside door
15 male stall door
16 male stall door
17 male urinal
18 male urinal
19 male toliet
20 male toliet
21 male faucet
22 male faucet
23 male shower
24 male shower

sample # Nov. 4 Nov. 7 Nov. 11 Nov. 14 Nov. 18 Nov. 21
1 white and blue green mold--2 white dots and green mold-2 green super mold, white dots-2 greenish grey superduper mold, pink dots, white dots-3 pink dots, white dots, grey green superdoper mold, green dots-4 grey green superdoper mold, green moldy dots, white splotch-3
2 white-1 pale dots-1 white dots-1 white dots-1 white dots-1 white dots-1
3 white-1 pale dots and white fuzz-2 white dots, white yellow dots, white fuzz-3 white dots, pink mold, yellow mold, yellow dots, white mold-5 pink mold, yellow mold, white dots, yellow dots, yellow mold-5 white mold, yellow mold, white dots, pink dots, yellow dots-5
4 white fuzz-1 white mold and yellow dots-2 yellow dot, white dot-2 white dots, yellow dots, white mold, yellow mold-4 yellow dots, white dots, orange dot, white mold, white brush stroke-5 yellow streak, white mold, orange dots, white dots, yellow dots-5
5 white-1 yellow mold, white mold-2 green mold, white fuzz, yellow dots-3 brown mold, white mold, yellow dots, orange dots, white dots, white mold-6 white mold, green mold, yellow dots, white dots, orange dot, brown mold-6 brown mold, yellow dots, white dots, orange dots, white mold, green/black mold-6
6 white dots and white fuzz-2 white mold, green tint mold, white dots-3 yellow mold, green mold, black mold, white fuzz patch, white mold-5 white fuzz patch, grey fuzz patch, orange fuzz patch, black fuzz patch, green mold, white dots, yellow dots-7 pink mold, white fuzz patch, grey fuzz patch, orange fuzz patch, green mold, yellow dots, white dots-8 pink mold, white fuzz patch, grey fuzz patch, green fuzz patch, yellow fuzz patch, orange fuzz patch, white dots, yellow dots, green mold-9
7 yellow mold, white dots, blue green mold-3 white mold, blue green mold, yellow mold, and white dots-4 yellow mold, brown mold, white mold, white dots-4 brown mold, white mold, grey mold, yellow mold, white dots with branches-4 white mold, brown mold, white dots with branches, grey mold, yellow mold-5 brown dots with branches, grey mold, white mold, brown mold, yellow mold-5
8 green fuzzy mold, white dots-1 green fuzzy mold, green bacteria, yellow spot, white dots-4 yellow dots, white dots, green mold, white brown mold, green bacteria-5 orange dots, yellow dots, white dots, brown mold, gray mold-5 yellow dot, white dot, orange dots, brown mold, black mold-5 black mold, brown mold, orange dots, white dots, and yellow dots-5
9 white dots, blue green mold-2 green blue mold, white dots, white mold-3 black mold, green mold, white mold-3 black mold, grey mold-2 black mold, grey mold, white mold, purple mold-4 green mold, purple mold, black mold, white spots-4
10 white mold, yellow mold, white dots-3 blue green mold, green mold, white mold, white dots white mold, green mold, white fuzz, white dots-4 pink mold, grey mold, white spots, yellow spots, white mold-5 orange dot, white dots, white mold, pink mold, brown mold, green mold, yellow spots, yellow peachy blotch-8 peachy blotch, yellow spots, whtie spots, green mold, brown mold, pink mold, white mold-7
11 none-0 white bacteria-1 white bacteria white spots, pink spots, grey spots-3 pink dots, orange dots, white dots, grey spot-4 pink dots, orange dots, white dots, grey spots-4
12 white mold-1 blue green mold, white mold, white bacteria-3 white dots, green mold-2 big ass grey mold, white dots, yellow dots, white mold-4 big ass grey mold, white dots, yellow dot, white mold-4 big grey mold, white dots, yellow dots, white mold, pink mold-5
13 white dots-1 white mold, yellow dot, white dots-3 yellow dots, white dots, white mold-3 white mold, green mold, white dots, yellow dots-4 green mold, white mold, yellow dot, white mold, white dots-5 green mold, green line, yellow orange dot, pink dot, white mold, wgrey dots-6
14 yellow fuzz-1 green mold, white dots-2 green mold, white dots, yellow dots-3 yellow dots, brown mold, white dots-3 yellow dot, orange dot, white dot, brown mold-4 yellowdot, orange dot, white dot, brown mold-4
15 blue green mold, white mold, white dots, yellow mold-4 green mold, white mold, white dots-3 white fuzz, white mold, green mold, yellow dot-4 grey mold, brown mold, white mold, yellow dot, brown dots-5 white mold, black mold, pink mold, white dot, green mold, brown dots-6 brown mold, white mold, green mold, black mold, pink mold, brown dots-6
16 white mold, yellow mold, white dots-3 brown mold, white mold, green mold green mold, white mold, brown mold-3 black mold, brown mold, light-brown mold, white mold, yellow spots-5 black line spluge, black dots, white mold, yellow dot, brown mold-5 black mold, brown mold, white mold , black dots, yellow dot-5
17 white mold, white dots-2 brown mold, white mold, white dots-3 brown mold, white mold, white dots-3 white mold, white spots, yellow spots, brown mold-4 brown mold, white mold yellow mold white dots-4 white omold, brown mold, white dots, yellow mold-4
18 white mold-1 white mold-1 white mold-1 white mold, pink spots, grey mold white mold, pink dots, grey mold, pink mold-4 white mold, grey mold, pink dots, pink mold-4
19 white mold and white dot-2 white mold, teal mold, white dots, white hair-like spirals-4 white swirly, green mold-2 white swirly, black spots, white spot-3 white spot, black mold, white swirly-3 white swirly brown mold white dot-3
20 yellow/white blob, white dot-2 yellow-white blob, yellow dots, white dots, white mold-4 yellow dots white dots white mold-3 yellow dots, white spots, black spots, white mold-4 white spots, yellow spots, orange spots, white mold, black dots-5 yellow spots, orange spots, white spots, black spots, white/clear branches-5
21 white dots-1 white mold, white dots-2 white mold, white dots, white mold black center-3 white mold, white mold with black center, white spot-3 white mold, black mold, peach dot, pink dots-4 pink dots, white mold, peach dots, black mold-4
22 white dots-1 whtie dots-1 yellow dots white dots-2 yellow dots, pink dots, white dots-3 white dots, yellow dots, pink dots, white mold-4 white dots, white colony, peach dots, pinks dots, pink mold-5
23 white dots, white mold-2 white dots, white mold, yellow dots-3 white dots, yelllow dots, green mold, white mold-4 brown mold, green mold, white dots, yellow dots, purple/reddiish dots-5 yellow dots, white dots, green mold, white mold, purple/reddish dots, brown mold-6 green mold, brown mold, brown dots, white, dots, yellow dots, orange dots, pink dots, gold mold-8
24 white dots, yellow mold-2 white dots, white brown mold-2 white orange dots and brown mold-2 brown mold, yellow dots, white orange dots, pinkish/reddish dots-4 brown mold, yellow dots, white orange dots, pinkish/reddish dots-4 pink dots, yellow dots, orange dots, brown mold, white dots, brown dots-6

ecoli azotobacter streptocotococci staphyloccus Candida albicans proteus thiothese gelatinosa shannon weiner test
1 1
2 1
3 1 1 1
4 1 1 1 1
5 1 1 1
6 1 1 1
7 1
8 1 1 1
9 1
10 1 1 1
11 2 1 1
12 1 1 1.499
13 1 1 1
14 1 1 1
15 1
16 1
17 1 1
18 1
19 1
20 1 1 1 1
21 1 1
22 1 1
23 1 1 1
24 1 1 1 1 1.481

21 8 9 14 1 2 1 totals

Average Mean Boys 2.25 t=.11
Average Mean Girls 2.4

Breakdown By Location Breakdown By Bathroom

Location Bacteria Amount Bathroom Bacteria Amount
outside door 8 Girls 29
stall door 9 Boys 27
urinal 9
toliet 9
faucet 8
shower floor 13

Analysis and Discussion

Due to the plates of bacteria we collected and the bacteria we identified, we have come to the conclusion that we must fail to reject our null hypothesis. After the observations of the bacteria in the plates, it was proven that the female bathroom contained more bacteria than the male bathroom. Our original hypothesis was based upon femalesÕ frequent uses of the bathroom and their hygiene products. Our hypothesis also took into consideration that males use bathroom less frequently and do not normally use aerosol products. Between the two bathrooms we found seven different types of bacteria including: ecoli, strep, staph, azobat, proeteus, candida, and thio. All of these bacteria are harmless and even healthy is small quantities. Only mass quantities or after prolonged exposure, do these bacteria reach unsafe levels. The levels found in our research are healthy in their presence. It was only until we cultured them in the Petri dishes did they reach unsafe quantities. In order to keep these bacteria quantities at a safe level the bathrooms must be cleaned daily or even twice a day. This cleaning process will eliminate large quantities or a continual buildup of bacteria. This will make for a healthier, safer, and happier bathroom experience.

If we were to continue further into our research on this topic we would, start by including more locations such as the other bathrooms in Peabody or in other dorms. After we have broadened our experimental locations, we would look into the time of day that the samples would be taken and or the day of the week. A series of sample taking on a weekly or bi-weekly basis would also help to make conclusions on the consistency of the bacteria present. Limitations we experienced could be avoided in the future if we had more knowledge on identification of bacteria and the resources to classify the types present. Other considerations for more thorough documentation would included a constant monitoring system in which we could later observe the changing process the bacteria colonies go through.

Further questions we have on this topic include: what is the bacteria growth really due to, the cleaning process that exists or the usage of the bathroom by the dorm occupants? Also, do the cleaning products used target the specific bacteria found in the bathroom or are they effective in the prevention of them?

Works Cited

Wilson, Michael, Mc Nab, Rob, and Henderson, Brian. Bacterial
Disease Mechanisms
. Cambridge: University Press, 2002.

Gillies, R.R. and Dodds, T.C. Bacteriology
. 4th ed. New York: Churchill Livingstone, 1976

Dharan, S., Mourouga, P., Copin, P., Bessmer, G., Tschanz, B., and
Pittet, D. “Routine disinfection of patients’ environmental surfaces.
Myth or reality?” Journal of Hospital Infection 42:2
(1999): 113-117.

Zacheus, O.M. and Martikainen, P.J. “Occurrence of heterotrophic
bacteria and fungi in cold and hot water distribution systems using
water of different quality.” Canadian Journal of
41:12 (1995): 1088-1094.

Barker, J. and Bloomfield, S.F. “Survival of Salmonella in bathrooms
and toilets in domestic homes following salmonellosis.”
Journal of Applied Microbiology 89:1 (2000): 137-144.

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