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Typhoid fever is a bacterial disease that affects people around the world. Although typhoid fever is curable, antibiotic resistance is a growing concern and is expected to kill more people than cancer by 2050. Typhoid fever is caused by two subsets of Salmonella bacteria- Salmonella Typhimurium and Salmonella Typhi. Salmonella Typhimurium causes symptoms of food poisoning in humans and Typhoid fever in mice, where Salmonella Typhi causes the symptoms of Typhoid fever in humans. The bacteria are found throughout the body when infected, including the blood, macrophages, GI tract, and ovaries. At the cellular level, Salmonella bacteria are Gram-negative; meaning it has an outer membrane made out of lipopolysaccharides, in addition to the typical plasma membrane and peptidoglycan layer of Gram-positive bacteria.

With this in mind, we will be using Salmonella Typhimurium as our model organism. Salmonella Typhimurium is a sufficient model organism for our experiment because as described previously, it causes enteric fever symptoms of salmonella in Mice similar to what would be seen in a Salmonella Typhi in humans. Because the effects of S. Typhimurium in mice creates an accurate representation of S. Typhi in humans, most of our findings can be applied to the infection in humans.

The cosmetic mucin product are sourced from from korea exact source unknown. The cosmetic is assumed to be a 100% snail secretion filtrate. The stock DMSO used is 50% concentrate and the stock Ampicillin is 50 ug/mL. The standard Salmonella concentration is 10^5 bacteria per milliliter. The DMSO and Salmonella are sourced from preheld stock within the lab, and the Ampicillin is sourced from Research Products International Corp, in Mount Prospect, IL.

The Effect of the Snail Mucin on

Salmonella Typhimurium

Joseph Martensen, Danielle Volden, Casidy Phommatha, Lana Simpson

Department of Molecular, Cellular, and Developmental Biology

Methods

Objective

Introduction

Conclusions

Results

Acknowledgements

Future Direction

References

  1. To see if snail mucin will kill or inhibit the growth of Salmonella Typhimurium.
  2. To test the antimicrobial properties and find active ingredients in snail mucin
  3. To test the efficacy of snail mucin as an antibacterial agent, both with the max dose achievable in blood and subsequent diluted doses.

 

Dose Response

  1. Start off by making a dilution series. Add 100µL of DMSO and 100µL of the max dose solution in A1 to A2, creating a 1:2 ratio or a 5% concentration.

  • Then, add 100µL from the solution from A2 and 100uL of DMSO into well A3, creating a 2.5% solution. Repeat this process until wells A1-A5 are filled.

  • Pipette the remaining bottom 3 rows with DMSO, this will be the negative control.

  • To incubate, cover the plate with an adhesive sticker and place in the incubator at 37 C for 24 hours

  • Measure absorbance in spectrophotometer

Our results only allows us to conclude that the snail mucin cosmetic does not inhibit the growth of or kill Salmonella Typhimurium. While our data shows statistical hits, the data is still inconclusive due to issues with our negative control. One factor that could have affected our data was that we were not able to obtain more live snails, so we had to conduct this experiment with cosmetic snail mucin. Although the compound was listed to be 100% snail mucin filtrate, we believe that the mucin was dissolved in an unknown alcohol solvent (based on smell), so DMSO could be an ineffective negative control. While our results cannot conclude any effective antibiotic behavior, the dose response graph does however show the possibility of the compound being an endocrine disruptor. Lower concentrations of the mucin did decrease the final absorbance read in the well. These results are also not statistically viable no negative trend.

Hypothesis

In Future studies, live snails and natural snail mucin should be used. Because the results show the possibility of a endocrine disruptor, longer dilution series should be completed, until a full inverse bell curve is seen. Additionally, testing specific compounds within mucin individually should be considered. With sufficient funding all major compounds may be systematically tested.

We would like to thank Biological Sciences Initiative (BSI) and Howard Hughes Medical Institute to fund the drug discovery lab. We would also like to acknowledge Corrie Detweiler, the Principle Investigator and Sponsor of research. Finally, we would like to give a huge thanks to Pam Harvey and our wonderful TAs, Emma Tilley and Emma Bruce-Brown, for guiding us through this experiment and research.

  • The biomedical scientist | magazine of the IBMS. (n.d.). Retrieved October 11, 2022, from https://thebiomedicalscientist.net/
  • Pitt, S. (2019, November 14). Snail Slime: The Science Behind Molluscs as Medicine. Retrieved October 11, 2022, from https://theconversation.com/snail-slime-the-science-behind-molluscs-as-medicine-125156

Figure 1 (Left) Max Dose Experiment: Snail Mucin at 10% concentration shows near identical absorbance to negative control (DMSO) and did not result in any absorbance values below or above 2 standard deviations from the mean of the negative control (red line).

Figure 2 (Below) Dose Response Experiment: All Dilutions fail to show and absorbance values below or above 2 standard deviations from negative control mean (red line). Lower concentrations of Mucin consistently resulted in lower absorbances.

Snail Mucin has antibacterial properties that will kill or inhibit the growth of Salmonella Typhimurium.

Abstract

Salmonella Typhi is the main cause for typhoid fever, which is a life-threatening illness that affects many people daily. Although typhoid fever is curable, antibiotic resistance is a growing concern and is expected to kill more people than cancer by 2050.

Snail mucus has been normally used for skin care. However, it has many antibacterial properties that could be used to kill or inhibit the growth of Salmonella Typhimurium. Previous students that have taken the discovery lab have been successful in their research with snail mucin, and were able to obtain conclusive data.

 

Max Dose

  1. To begin, dilute the snail mucin by adding 20µL of the compound to 180µL of DMSO, creating the max dose (10% snail mucin).

  • Next, pipette 90µL of Salmonella into six wells of a 96 well plate in a 2 by 3 grid formation.

  • Pipette 10µL of the mucin max dose into 1A and 1B, and then pipette 10µL of DMSO into 2A and 2B as a negative control. Add 10µL of ampicillin into row C as a positive control.

  • To incubate, cover the plate with an adhesive sticker and place in the incubator at 37 C for 24 hours

  • Measure absorbance in spectrophotometer

Image of snail mucin cosmetic used