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.

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
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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
• Supervisor's Name: Graham, Dr. E., 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: https://theses.gla.ac.uk/id/eprint/8013