A phenotypic and genotypic investigation of Mycoplasma felis

McLellan, Heather (2017) A phenotypic and genotypic investigation of Mycoplasma felis. MSc(R) thesis, University of Glasgow.

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Abstract

Mycoplasma felis is frequently isolated from cats showing signs of respiratory or ocular infection however its role as a pathogen is still undefined. Some evidence suggests that M. felis may be a pathogen in ocular infections however evidence for pathogenic involvement of respiratory isolates is far less definitive. Ocular clinical isolates were cultured to identify phenotype; antimicrobial susceptibility and haemolytic activity. The strains were then sequenced along with a reference strain using Next Generation Sequencing technology, to determine if phenotype could be correlated with genotype and identify any genetic potential for virulence. Six antimicrobials were tested to identify antimicrobial resistance on a range of isolates and the reference strain NCTC 10160. Fluoroquinolones were the most effective; however, recommendations state these should be employed conservatively as a third line antimicrobial, due to their importance in human medicine. Tetracyclines, the first line of treatment in M. felis infection, were also effective with MIC90s of 0.06 μg/mL and 1 μg/mL for doxycycline and oxytetracycline, respectively. Little variance was observed between isolates, with only macrolides showing decreased efficacy. The reference isolate NCTC 10160 (from 1967) demonstrated the same susceptibility as the clinical isolates (2008-2014) and so this was not considered to be novel or emerging resistance. Haemolytic activity was observed in all isolates. The clinical isolates were sequenced using Next Generation Sequencing technology to establish if the observed phenotype correlated with a specific genotype. No antimicrobial resistance markers were identified. Upon alignment with a reference genome (M. cynos C142) several genes shared sequence homology with good coverage, including those involved in nutrient uptake and lipoprotein signalling; however, no definitive markers of virulence were identified. The generated MIC data will be useful as currently there are no established breakpoints in animal mycoplasmas. The MIC data available is limited and previously has been generated from research projects such as this. Overall, the 3 pathogen status of M. felis is still unclear. No antimicrobial resistance markers or known virulence markers were identified in this study, although the genes used for alignments were not exhaustive and the highly mutable genome of mycoplasmas may mean divergent or novel resistance genes are present.

Item Type: Thesis (MSc(R))
Qualification Level: Masters
Keywords: Mycoplasma, antimicrobial resistance, genotype, phenotype, whole genome.
Subjects: S Agriculture > SF Animal culture > SF600 Veterinary Medicine
Colleges/Schools: College of Medical Veterinary and Life Sciences
Funder's Name: UNSPECIFIED
Supervisor's Name: Graham, Dr. E. and Gallagher, Dr. A. and Rich, Dr. T.
Date of Award: 2017
Depositing User: H McLellan
Unique ID: glathesis:2017-8013
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 17 Oct 2017 07:47
Last Modified: 07 Nov 2017 08:24
URI: http://theses.gla.ac.uk/id/eprint/8013

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