This August, Student Research Fellows presented their research and findings at a Research Symposium. Many of these students were from the Honors Program, so we are having two such students present a Lunch and Learn on Tuesday, September 5th from 11:00am until 11:50am in the Pickell Hall Conference Room. These Honors students will explain a little about the Student Research Fellowship program, how you can participate in the future, and then present their individual research projects and the results. Below are short synopses of each student’s research:
Horizontal Gene Transfer in the Presence of Antiseptics
Student Researcher: Austin Vanwyk, Faculty Researcher: Dr. Anne Spain
Antibiotic resistance among bacteria is arguably one of the more troublesome topics in medicine today. Genes for resistance can be transferred between bacteria, and it has been found that environmental stressors such as antibiotics can increase the rate at which transfer occurs. However, little research has been done to see what effect antiseptics may have on transfer of resistances. Chlorhexidine was selected as the antiseptic to be used in this research because of its wide spread use in hospitals. Door handles and other regularly touched surfaces from clinical and non-clinical sources were swabbed and then plated, using a type of agar for gram-positive bacteria and another for gram-negative. Ten gram-negative and 20 gram-positive isolates were obtained and assays were done to determine their resistance to six different antibiotics. Four-gram positive isolates have resistance to the antibiotic ceftriaxone. To assess gene transfer, multiple combinations of ceftriaxone resistant gram-positive bacteria and susceptible gram-negative bacteria were grown together with varying levels of chlorhexidine, the hospital antiseptic. The cultures were incubated for 24 hours then plated on agar containing ceftriaxone. The gram-positive isolates were able to grow on the ceftriaxone plates; however, no gram-negative isolates were grown. This indicated that no resistance transfer occurred, though, more trials could yield different results, preliminary data supports that chlorhexidine does not induce transfer of antibiotic resistance genes.
Geometry Optimization and Energy Calculations for Hydrogen Bonded 1:1 Co-Crystals of Carboxylic Acids with Sulfisomidine and Sulfamethazine
Student Researcher: Jordan Lee, Faculty Researcher: Dr. Mark Thomson
A co-crystal is defined as two or more compounds forming a unique crystal with unique properties. Co-crystallization is currently being explored as a method to change drug storage, delivery, and action by co-crystallizing drugs with other compounds. This project focuses on the co-crystallization of sulfamethazine and sulfisomidine, two antibacterial drugs, with various carboxylic acids. These drugs only differ chemically in the position of a single nitrogen atom, but sulfamethazine forms co-crystals in the lab with relative ease while it is far more difficult to form a co-crystal using sulfisomidine. This project attempts to explain this phenomenon using Gaussian 09W software to complete DFT energy calculations and geometry optimizations. An energy calculation was performed on the original co-crystal, followed by an optimization calculations, finally a second energy calculation. This sequence of calculations determined that sulfisomidine must change its conformation from the ideal optimized structure more than sulfamethazine does, and therefore must overcome a greater energy barrier. The eventual goal is to apply these findings to practical pharmacological scenarios to improve the effectiveness of these sulfa drugs in the body.
To learn more, please join us for this Lunch and Learn on Tuesday, September 5th at 11am. Pizza will be provided for all those who sign-up beforehand. Please make sure to RSVP via email at firstname.lastname@example.org before noon on Monday, September 4th as space is limited.