The Effects of Tigecycline on Pseudomonas aeruginosa with relations to nosocomial infections in patients with Cystic Fibrosis

Pseudomonas aeruginosa is a gram-negative bacterium that can infect and harm plants and animals. One of these infections that are harmful specifically to humans is nosocomial infections which are those that are impacting patients during their time being hospitalized. The research is focused on patients specifically with Cystic Fibrosis due to them being highly susceptible to infections because of how frequently hospitalized they are. This is significant in understanding the correlation between antibiotic treatment, hospitalizations, and susceptibility to Pseudomonas aeruginosa in CF patients. Cystic Fibrosis is an inherited disorder that can be life-threatening due to the damage it has on the digestive system and lungs in the body. As of right now, there is no cure for Cystic Fibrosis and nosocomial infections harm these patients that already have a low immune system. Pseudomonas aeruginosa does not have many known antibiotics that work well against it due to the resistance increasing. Tigecycline is a tetracycline antibiotic that is used often when other known antibiotics stop working against bacterial infections. The research being conducted consists of testing Tigecycline on Pseudomonas aeruginosa through the Minimum Inhibitory Concentration Test, Biofilm inhibition Assay test, and the Kirby Bauer/Disk Diffusion method. These three will result in analyzing the data collected to determine the effectiveness of Tigecycline on Pseudomonas aeruginosa. The importance of finding an effective antibiotic for Pseudomonas aeruginosa will help in identifying more treatment options and lead to an advancement in microbiological research.

Hello My name is Kenneth axelbank and my research was on the effects of Tigecycline on Pseudomonas aeruginosa with relations to nosocomial infections in patients with cystic fibrosis. Nosocomial infections are infections that occur from a patient’s time in a hospital and patients with cystic fibrosis are related due to them being frequently in the hospital due to treatments and checkups which leave them more susceptible to nosocomial infections. Pseudomonas aeruginosa (or pa) is a gram-negative bacterium, meaning that it causes diseases in plants and animals and is more likely to cause infections and become resistant to antibiotics that have been known to inhibit the bacteria. PA is also coccus shaped, meaning that it is circular. Tigecycline is known to work against multi-drug resistant bacteria meaning that when a bacterium becomes resistant to various antibiotics, tigecycline is sometimes an effective alternative. Some other known antibiotics to be effective are amikacin, penicillin, piperacillin, and ciprofloxacin. Amikacin will be used as a positive control. The three tests that will be performed in this experiment are the Minimum inhibitory concentration test, Kirby Bauer disk diffusion, and antibiofilm assay. The results for the MIC tests were shown in these graphs. For the positive control Amikacin which Is shown in the top graph to the left, the MIC was 4 micrograms per milliliter and had approximately a 10 percent survivability rate. For tigecycline, the first trial is shown right below which shows the MIC to be about 64 micrograms per milliliter and this is known to be not too effective, but shows some area of inhibition. For the two other trials of Tigecycline, the MIC came out to be 256 micrograms per milliliter which is not effective in inhibiting PA. This may be due to these two trials being done at a later date and light having an effect on its effectiveness as an antibiotic. For the antibiofilm assay results the top image shows the quantitative data that was collected for Tigecycline. When a t-test was performed, the p-value was greater than 0.05 meaning that the null hypothesis was rejected, and the data was not significant. This would mean that tigecycline would not be an effective inhibitor for biofilm. For the Kirby Bauer test, the image to the left, it shows amikacin and it has a large zone of inhibition for all three disks and the image on the right shows tigecycline as having no zone of inhibition. This would mean that the Kirby Bauer test proves that tigecycline is not an effective antibiotic. In conclusion, tigecycline was proved to be ineffective as an inhibitor against PA and further research could be focused on a different antibiotic that is similar structurally to amikacin and different from tigecycline. A possibility in improving this experiment would be to perform the experiments at the same time or keep tigecycline covered in a material that can block the light from passing through. This is largely due to light being found to reduce tigecycline’s effectiveness which was not previously known before the start of this experiment. Lastly, the three tests showed tigecycline to not have an impact on PA and nosocomial infections in patients with cystic fibrosis. In a MIC, the lower concentrations that it is effective at inhibiting the growth of bacteria, the better it is. In a Kirby Bauer test, the zone of inhibition is necessary to measure the effectiveness of an antibiotic. Sadly, Tigecycline did not prove to be effective, but it can still be useful in leading to hopeful antibiotics in the future that may work. I would like to acknowledge Dr. van Hoek for being a great mentor and for giving me the idea to perform the experiment. I would also like to thank GMU Oscar/URSP for funding this experiment. I would also like to thank my advisor, Tahmina Rahman for introducing me to my mentor, and Morgan Tasseff for training me and for helping out in the lab to be able to perform these experiments. Here are the works cited. Thank you for listening to my presentation!