The process of translocation of threatened
wildlife may have unforeseen consequences on pathogen transmission and
evolution in host populations. Our understanding of some of the epidemiological
features of infectious disease in vulnerable populations can be enhanced by the
use of genomic sequencing of microbes in natural ecosystems. The genomic
epidemiology of a prevalent rail-associated endemic bacterium, Campylobacter sp. nova 1, and a host-generalist bacterium, Salmonella spp., was explored in a well-described population of a
New Zealand endangered flightless bird, the takahe (Porphyrio hochstetteri). The distinctive population structure of
translocated takahe provides a unique opportunity to investigate the influence
of host isolation on enteric microbial diversity. Whole genome sequencing, ribosomal
multi-locus sequence typing (rMLST) and CRISPR analysis was performed on 70 C. sp. nova 1 isolated from multiple takahe populations. C. sp. nova 1 was genomically diverse and multivariate analysis of 52
rMLST alleles revealed location-associated differentiation of C. sp. nova 1 sequence types. Possible explanations for the observed
pattern include; the spatial expansion and isolation of hosts resulting in
reduced gene flow of Campylobacter
spp. and allopatric speciation, the presence of heterogeneous environmental
attributes influencing sequence type carriage or cross-species transmission of Campylobacter spp. from sympatric
reservoir hosts. The same methods were used to analyse Salmonella spp. isolated from a single island population of takahe
and their environment. Salmonella
spp. isolated from takahe, their environment and a reptile showed identical
rMLST profiles suggesting a shared source or transmission within the location
not present in other populations. This study suggests subtle but important
differences in host-microbe relationships may occur as a consequence of
conservation management which has important implications when relocating
wildlife populations.