The temporal distribution of planktonic protists in southwestern Alberta and their role in the persistence of the human pathogen Campylobacter jejuni

Abstract

The temporal dynamics of Campylobacter jejuni and protistan community structure in southwestern Alberta rivers were studied over a 1 -year period. Culture-based isolations of C. jejuni were predominantly from the winter while real-time quantitative PCR indicated fluctuating densities of C. jejuni with no seasonal trend and no correlation with physicochemical properties of water. Protistan communities clustered according to season rather than location. Clinical C. jejuni isolates from southwestern Alberta survived longer when co-cultured with the model protozoan Acanthamaoeba polyphaga than in the presence of by-products or growth medium. The use of wild type and mutant C. jejuni 81-176 strains revealed a cytotoxic effect toward A. polyphaga, and that invasion requires a functional flagellar apparatus but not quorum sensing nor cytolethal distending toxin. Combined, findings illuminate seasonal patterns of C. jejuni and protists and support the hypothesis that C. jejuni exploit phagotrophic protists as a survival mechanism in water. IV