Gram Positive Bacteria & Antibiotic Resistance
Sampling of Gram-Positive Bacteria and Antibiotic Resistance Resting
We thought it would be interesting to find out the different bacteria that grow on things we use on a daily basis and the level of antibiotic resistance that those bacteria have. We chose to swab the toilet seat in the MATC women’s bathroom and the ATM machine in the commons area on campus. We were certain the ATM would be dirtier than the toilet seat since the bathrooms get cleaned every day.
The first step we took in testing our hypothesis was to take a bacterial culture of both surfaces; using a sterile cotton swab to collect our samples. We started by thoroughly swabbing the top-side of the middle toilet seat in the women’s restroom and taking a separate swab from the keypad of the ATM machine. We them transferred our collected sample onto two separate TSA plates by swabbing the agar in a zigzag fashion, rotating the petri dish to spread the bacteria in various directions. This culturing technique helped us to see the full growth of the biofilm that would be growing after inoculation.
After the fifth day of inoculation, we were able to visibly see the various bacterial colonies of our biofilms. We proceeded to gram-stain a colony from each biofilm, in search of colonies of gram-positive bacteria. There are very specific steps that must be taken when gram- staining bacteria; the first step being to collect a colony of bacteria from one of the TSA plates, then transfer the colony from the TSA plate to the slide. We used a sterile loop (sterilized by placing the loop in the flame of a Bunsen burner to eliminate pre-existing bacteria) for the transfer and smeared the sample onto the slide, spreading out the bacteria as much as possible in the center of the slide. We heat fixed the slide by quickly passing the slide through the open flame of a Bunsen burner three times. Normally when using the gram-staining technique, you would use the loop to place a droplet of water on the smear prior to
We thought it would be interesting to find out the different bacteria that grow on things we use on a daily basis and the level of antibiotic resistance that those bacteria have. We chose to swab the toilet seat in the MATC women’s bathroom and the ATM machine in the commons area on campus. We were certain the ATM would be dirtier than the toilet seat since the bathrooms get cleaned every day.
The first step we took in testing our hypothesis was to take a bacterial culture of both surfaces; using a sterile cotton swab to collect our samples. We started by thoroughly swabbing the top-side of the middle toilet seat in the women’s restroom and taking a separate swab from the keypad of the ATM machine. We them transferred our collected sample onto two separate TSA plates by swabbing the agar in a zigzag fashion, rotating the petri dish to spread the bacteria in various directions. This culturing technique helped us to see the full growth of the biofilm that would be growing after inoculation.
After the fifth day of inoculation, we were able to visibly see the various bacterial colonies of our biofilms. We proceeded to gram-stain a colony from each biofilm, in search of colonies of gram-positive bacteria. There are very specific steps that must be taken when gram- staining bacteria; the first step being to collect a colony of bacteria from one of the TSA plates, then transfer the colony from the TSA plate to the slide. We used a sterile loop (sterilized by placing the loop in the flame of a Bunsen burner to eliminate pre-existing bacteria) for the transfer and smeared the sample onto the slide, spreading out the bacteria as much as possible in the center of the slide. We heat fixed the slide by quickly passing the slide through the open flame of a Bunsen burner three times. Normally when using the gram-staining technique, you would use the loop to place a droplet of water on the smear prior to