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Title: Modeling of plasmid dynamics and persistence in a community of hosts
Author: Martins, Sonia Cristina Santos
ISNI:       0000 0004 2731 8780
Awarding Body: University of Birmingham
Current Institution: University of Birmingham
Date of Award: 2013
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Some bacterial plasmids have a narrow (NHR) while others have a broad host-range (BHR), facilitating the propagation of antibiotic resistance genes through natural communities. An extended host-range should mean less adaptation to any particular host and this should result on average, in a greater fitness burden for its hosts.Thus, what are the advantages of having a broad host-rage? The dynamics of transfer of BHR plasmids competing with faster growing NHR-plasmid bearing cells in two-species assemblages in chemostats and biofilms was analysed using mathematical models. In chemostats a costly NHR plasmid that can survive in a single species population could not survive in a two-species assemblage. Adding a BHR competitor helps the NHR plasmid to survive and coexistence of both plasmids becomes possible if ttre plasmids are incompatible. In two-species biofilms the BHR plasmid is the better competitor despite the higher costs, whereas NHR spreading is severely hindered by biofilm patchiness. Experimentally, mating experiments and growth curves showed a strong dependency of plasmids transfer frequency and fitness burden on species background. Overall, this work demonstrates how competition, differences in host-range and compatibility relationships between plasmids can enhance the chances of plasmid persistence in two-species assemblages.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: QH301 Biology