Team:UT Dallas/Safety


Our completed system aims to prevent and treat dental caries through elimination of S. mutans cells. There is no risk to the safety and health of the general public. Since the product is only going to be produced in a certain condition specific to the environment intended, we have implemented a repression system that only expresses the product when it is needed. Norspermidine, or nspc needs to be refrigerated at 2-8 degrees Celsius, which is your average refrigerator temperature. If this product is not at this temperature, the E.coli will not survive. You cannot throw this product in the trashcan. To properly dispose of our product you would need to autoclave it. The E.coli we used is not harmful, but could potentially be harmful through manipulation. Like many bacteria, this E. coli could be manipulated in a lab setting by changing the plasmids. We understand there could be some ethical issues by giving E. coli to pets. While this product should not be harmful when used correctly, pets cannot voice their concerns about being given bacteria to prevent cavities. The choice to use this product is at the discretion of the pet owner.

We considered several safety aspects in regards to our project:

1. Do the biological materials used in your lab work pose any of the following risks? Please describe.

a. Risks to the safety and health of team members or others working in the lab?
     There are low safety and health risks to the team members or to others working in the lab. The organisms we are working with are Escherichia coli K12 strain DH5alpha which is a level 1 safety organism. Also, we are only isolating genetic parts for a biobrick from both S. mutans UA159 and M. catarrhalis 035E, which are biosafety level 2 organisms. This risk level is due to M. catarrhalis' ability to irritate and cause infections of the respiratory tract; whereas S. mutans causes dental caries. We have taken the necessary safety precautions in handling these organisms.

b. Risks to the safety and health of the general public, if released by design or by accident?
     There is low risk to the safety and health of the general public. The toxicity data for Norspermidine (3,3-Diaminodipropyamine) is not well characterized on the microscale level, more research is needed before implementing it for use. However, this is widely available. Our completed system aims to prevent and treat dental caries through elimination of S. mutans cells.

c. Risks to the environment, if released by design or by accident?
     If it were released into the environment, the E.coli cells would not likely pose a threat to organisms other than S. mutans.

d. Risks to security through malicious misuse by individuals, groups, or countries?
     No, there are no risks through misuse.

2. If your project moved from a small-scale lab study to become widely used as a commercial/industrial product, what new risks might arise? Also, what risks might arise if the knowledge you generate or the methods you develop became widely available?
     If this project were to become widely used as a commercial product, there is a higher risk for contamination from other organisms. There is also a possibility for S. mutans to adapt to the new mouth environment that would be created were our bacteria to be implemented as a cavity-prevention agent.

3. What safety training have you received (or plan to receive in the future)? Provide a brief description, and a link to your institution’s safety training requirements, if available.
     We have received online training through video and questionnaire as well as verbal instruction. We have also been instructed on UTD's lab safety standards and adhere to Biosafety level 2 guidelines.

Project Biosafety

     Escherichia coli (E. coli) DH5α strain was chosen as the chassis for our project. This strain is not considered to be pathogenic to humans or animals1. The DH5α strain is considered to be comparable to ACDP hazard group 1, and it is considered to be a disabled strain. The strain requires media supplementation of nutrients in order for growth, and as such, does not present an environmental hazard.

Certain parts were derived from bacterial species:
  • ComA, ComB, ComC, ComD, and ComE (used for quorum signaling) were extracted form Streptococcus mutans UA159 (from Dr. Idranil Biswas' lab at University of Kansas Medical Center). Because only parts are extracted and taken from this organism is believed to have a low disease risk of dental carries. This species is commonly found in the human mouth.

  • NspC (produces norspermidine to degrades biofilms) was extracted from Moraxella catarrhalis 035E (from Dr. Lawrence Reitzer's lab at the University of Texas at Dallas). This species of bacteria is responsible for cases of otitis media, chronic sinusitis, respiratory tract infections, systemic infections, meningitis, and bacteremia. Norspermidine can be harmful in contact with skin, inhalation, and can cause severe skin burns and eye damage. Proper procedures were followed when handling this organism and only one culture was needed to extract the part.

  • pFru (a promoter part) was extracted from Escherichia coli Mg1655 (from Dr. Stephen Spiro’s lab at the University of Texas at Dallas). This part consists of a promoter repressed by the Cra protein but is induced in the presence of fructose and is considered a very low risk part.

  •      Research was conducted in a BSL2 laboratory due to some parts deriving from organisms in risk group 2. Proper precautions were taken such as using proper microbiological techniques, protective clothing, biohazard signs, as well as using a biological safety cabinet when required.

         1. Risk Assessments for use of Genetically Modified Microorganisms
         2. Risk Assessment Example