A rapid method for detecting single nucleotide polymorphisms using antimicrobial resistance in Neisseria gonorrhoeae as a model

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dc.contributor.supervisor Ng, Lai King (Medical Microbiology) en
dc.contributor.author Cullingham, Kyle
dc.date.accessioned 2005-04-26T19:46:57Z
dc.date.available 2005-04-26T19:46:57Z
dc.date.issued 2005-04-26T19:46:57Z
dc.identifier.uri http://hdl.handle.net/1993/113
dc.description.abstract Chromosomal mediated antimicrobial resistance in Neisseria gonorrhoeae can develop as a result of three main processes including the alteration of target enzymes, changes in transmembrane transport channels and active efflux pump function. Single nucleotide polymorphisms (SNPs) of target genes such as DNA gyrase (gyrA) and topoisomerase (parC), together with mutations in the promoter regions of the efflux pumps norM and mtr can confer resistance to the macrolides, penicillins and fluoroquinolones. These SNPs were analyzed using the SNaPshot method to allow for rapid detection of resistant isolates. Oligonucleotides were developed in the 5’ to the 3’ direction, ending one nucleotide adjacent to the specific SNP of interest. Single base extension reactions were performed and were detected using capillary electrophoresis. The SNaPshot procedure from Applied Biosystems employed in this study adds a single fluorescently-labelled nucleotide complementary to this SNP at the 3’ end by a primer extension polymerase reaction. Then using capillary electrophoresis, the labelled nucleotide is detected, enabling differentiation between A, C, T, or G. SNP results obtained were verified using DNA sequencing and both single and multiplexed reactions were carried out to increase the efficiency of the procedure. Spiked urine samples were also observed to determine if SNPs could be detected clinically. Single reactions enabled the characterization of all confirmed and relevant SNPs. With multiplex primer extension, multiple peaks were observed, each corresponding to one of the SNPs in the gene. This technique was explored for its applicability to detect SNPs of gyrA and parC mutations. Observable SNP detection limits were seen in spiked urine samples at 108 cells/mL in as early as 4 hours. DNA sequencing results confirmed the SNPs identity in each case. Thus, capillary electrophoresis using the SNaPshot protocol is another way to rapidly identify clinically resistant strains of Neisseria gonorrhoeae. This technique has also been shown to reduce analysis time compared to DNA sequencing and produces the same results. en
dc.format.extent 1777867 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.rights info:eu-repo/semantics/openAccess
dc.subject Neisseria gonorrhoeae en
dc.subject capillary electrophoresis en
dc.title A rapid method for detecting single nucleotide polymorphisms using antimicrobial resistance in Neisseria gonorrhoeae as a model en
dc.type Electronic Thesis or Dissertation en
dc.type info:eu-repo/semantics/masterThesis
dc.degree.discipline Medical Microbiology en
dc.contributor.examiningcommittee Alfa, Michelle (Medical Microbiology), Mulvey, Michael (Microbiology), Zhanel, George (Medical Microbiology) en
dc.degree.level Master of Science (M.Sc.) en
dc.description.note February 2005 en

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