The microbial ecology of Campylobacter jejuni in New Zealand within a spatial-temporal framework : a thesis presented in partial fulfilment of requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Manawatu, New Zealand

Binney, Barbara Mary

The microbial ecology of Campylobacter jejuni in New Zealand within a spatial-temporal framework : a thesis presented in partial fulfilment of requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Manawatu, New Zealand

dc.contributor.author	Binney, Barbara Mary
dc.date.accessioned	2016-06-27T21:38:54Z
dc.date.available	2016-06-27T21:38:54Z
dc.date.issued	2015
dc.description.abstract	Campylobacter jejuni (C. jejuni) is an important cause of gastroenteritis internationally; it is a complex bacterium carried by multiple hosts, showing phenotypic and genotypic variation. This thesis systematically examines the molecular ecology and evolution of C. jejuni in New Zealand from the levels of population movement, phenotype, genome and metabolism. First, the demographic history of cattle, sheep and poultry importations into New Zealand (1860- 1979) was quantified. Australia was the most common reported source of cattle sheep and poultry, with large numbers of cattle and sheep being imported in the 1860s, and large numbers of poultry imported from the 1960s onwards. This suggests the population structure of cattle and sheep and the microbial organisms they carried may exhibit a founder effect. The second level investigated the phenotypes of related sequence types (ST) with generalist and specialist lifestyles and compared them at 42°C and 22°C on the basis of carbon source utilisation in Biolog phenotypic microarrays. The isolates utilised a total of 29 carbon sources in a pattern that clustered them together on the basis of ST at 42°C more than lifestyle and host. At 22°C they utilised a limited palette of carbon sources (9) related to the tricarboxylic acid cycle (TCA). The third level, used genomic comparisons to identify a putative new species C. sp. nov. 4 spp. in the Australian purple swamphen (Porphyrio porphyrio melanotus). Overall, the pattern of relationship between isolates associated with the pukeko (Porphyrio porphyrio melanotus), takahe (Porphyrio hochstetteri) and the Australian swamphen isolates suggested a recent common ancestor and then divergence after separation. Despite high levels of recombination in C.jejuni, the genomes grouped by clonal complex and ST, this suggests there are factors restricting regular recombination between more distant C. jejuni STs. The draft genomes for the wild-bird and agricultural-related isolates clustered by lineages in a host(s). The fourth level involved the comparison of C. jejuni metabolic pathways (subsystems) to identify host association. Type VI secretion system, Coenzyme A biosynthesis and Campylobacter spp. iron metabolism were identified as important pathways in distinguishing between wild-bird and livestock associated isolates.	en_US
dc.identifier.uri	http://hdl.handle.net/10179/8313
dc.language.iso	en	en_US
dc.publisher	Massey University	en_US
dc.rights	The Author	en_US
dc.subject	Campylobacter jejuni	en_US
dc.subject	Genetics	en_US
dc.subject	New Zealand	en_US
dc.subject	Microbial ecology	en_US
dc.title	The microbial ecology of Campylobacter jejuni in New Zealand within a spatial-temporal framework : a thesis presented in partial fulfilment of requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Manawatu, New Zealand	en_US
dc.type	Thesis	en_US
massey.contributor.author	Binney, Barbara Mary	en_US
thesis.degree.discipline	Veterinary Science	en_US
thesis.degree.grantor	Massey University	en_US
thesis.degree.level	Doctoral	en_US
thesis.degree.name	Doctor of Philosophy (Ph.D.)	en_US