Our results lend support to the hypothesis that installed logjams may enhance stream habitat not only by providing colonization surfaces for macroinverbrates, but also by altering the benthic environment of the surrounding habitat.
Although attacking the pathogen, antimicrobials also kill innocent bystanders, members of microbiota providing colonization resistance against invaders [ 3, 4].
For colonization with vegetative C. difficile cells to occur, there must be a disruption of the normal intestinal microbiota which usually provides colonization resistance against C. difficile [ 51, 52].
This suggests that the mycotoxins could have a role in promoting pathogen colonization in cattle by providing colonization niches, toxin entry into the submucosa or blood stream and preventing early recognition of an infection.
The human microbiota is considered to benefit the host by promoting the differentiation of the mucosal structure and function, stimulating both the innate and adaptive immune systems, and providing "colonization resistance" against pathogen invasion [ 10].
While endophyte species diversity did not differ between the host genotypes, BX production provided a colonization advantage to Fusarium species (Fig. 2; Saunders and Kohn 2009) confirmed in second field study (M. Saunders, A.E. Glenn and L.M. Kohn, unpublished).
The oral and vaginal environments may provide such similar colonization and growth conditions in a susceptible host.
A putative risk locus centering on the calmodulin gene, which can regulate cadherin function, and previous evidence for differential expression of a calcium activated chloride channel associated with colonization provide additional evidence for Ca2+-regulated cadherin involvement.
In both cases, it seems likely that specific colonization patterns provide physiological benefits for both partners in the association.
Understanding the factors that control the timing and specificity of bacterial colonization will provide insight into communication among the multiple partners in the coral holobiont and identify significant determinants in host vulnerability to bacterial disease and changing marine environments.
