Investigating the efficacy of nisin when combined with first line antibiotics in the treatment of...
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UNIVERSITY OF NOTTINGHAM Investigating interactions of nisin with first-line antibiotics in MRSA 252 and S. aureus NCTC 6571 Biochemistry Research project Joseph Clonan 2013 Project Supervisor: Dr. Boyan Bonev Word Count: 8,425
description
This was my third year dissertation project at the University of Nottingham. I spent roughly 4 months preparing my research and a further 4 months in a Class 1 Biohazard Containment Facility at the University of Nottingham, as I was working with MRSA. I regret not being able to continue my research as the results warranted further investigation.
Transcript of Investigating the efficacy of nisin when combined with first line antibiotics in the treatment of...
Investigating interactions of nisin with first-line antibiotics in MRSA 252 and S. aureus NCTC 6571
Joseph Clonan Biochemistry Research Project - 4099822University Of NottinghamInvestigating interactions of nisin with first-line antibiotics in MRSA 252 and S. aureus NCTC 6571Biochemistry Research project
Joseph Clonan2013
Project Supervisor: Dr. Boyan Bonev
Word Count: 8,425
ContentsAbstract3Background:3Method:3Results:3Conclusion:3Introduction4The onset of bacterial resistance to antibiotics4Mechanisms underlying acquired bacterial resistance4Staphylococcus aureus: a highly promiscuous genomeError! Bookmark not defined.Methicillin resistant Staphylococcus aureus6First line treatments for MRSA7Further approaches to treating MRSA8Antibiotics11Cell-wall synthesis inhibitors11Protein Synthesis inhibitors14Macrolides17Tetracyclines18Metabolic inhibitors19Polymixins20Hypotheses of interactions between nisin and antibiotics20Methods22Nisin Purification22Extraction of Nisin from Nisaplin (Dannisco Dupont, UK)22Extracting nisin fractions with Toyobutyl column22Reverse phase high pressure liquid chromatography of 10ml HCl wash using C18 column22MALDI-TOF-Mass Spectrometry using the LaserToF23Testing the activity of nisin23Establishing Minimum Inhibitory Concentrations24Sensitivity testing for NCTC 6571 and MRSA 25224Calculating MICs of the antibiotics to make ISA at MIC concentrations26Combining nisin and antibiotic in the same well to observe interactions determining change in zone size26Results29Testing the activity of nisin30Calculating MICs for antibiotics31Evaluating interactions of nisin and antibiotics combined in the same well34Discussion39Nisin activity and efficacy39Limitations of methodological approach and confounders40Suggestions for future research41Concluding statements42Acknowledgements42Glossary of terms43REFERENCES44
Abstract
Background: As a result of the widespread use of antibiotics, bacteria have both cause and opportunity to acquire resistance as a result of chromosomal changes or the exchange of genetic material through conjugative plasmids or transposons. L antibiotics are potent antimicrobial peptides originating from bacteria, which have low propensity for generating resistant bacteria.Objective: To investigates whether the lantibiotic nisin, may enhance the activity of first-line antibiotics.Method: Nisin is combined with antibiotics observe inhibition zone sizes in MRSA, and S. aureus NCTC 6571.Changes in the MIC of nisin were observed when nisin was in the presence of antibiotic incorporated into agar. Zone diameters were measured around wells containing either antibiotic, or antibiotic with nisin to observe interactions.Results: Nisin enhanced the activity of vancomycin and trimethoprim, and facilitated activity of colistin which was inactive when used alone. However, nisin was found to be antagonistic to the activity of tetracycline (p
