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Ciliate Ingestion and Digestion: Flow Cytometric Measurements and Regrowth of a Digestion‐Resistant C ampylobacter jejuni
Author(s) -
First Matthew R.,
Park Nina Y.,
Berrang Mark E.,
Meinersmann Richard J.,
Bernhard Joan M.,
Gast Rebecca J.,
Hollibaugh James T.
Publication year - 2011
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.2011.00589.x
Subject(s) - campylobacter , biology , ciliate , campylobacter jejuni , digestion (alchemy) , microbiology and biotechnology , ingestion , bacteria , food science , biochemistry , ecology , chemistry , chromatography , genetics
We measured ingestion and digestion rates of the pathogenic bacterium C ampylobacter jejuni by a freshwater ciliate C olpoda sp. to determine whether C ampylobacter is able to resist protist digestion. C ampylobacter and the nonpathogenic bacterium P seudomonas putida LH1 were labeled with a 5‐chloromethylfluorescein diacetate, which fluoresces in intact and active cells but fades when exposed to low pH environments, such as protistan food vacuoles. Ingestion and digestion rates were measured via flow cytometry as the change in ciliate fluorescence over time, which corresponded to the quantity of intracellular bacteria. The rate of C ampylobacter ingestion exceeded the digestion rate. Ciliates retained labeled C ampylobacter 5 h after ingestion was stopped. In contrast, ciliates grazing upon P . putida returned to baseline fluorescence within 5 h, indicating that P . putida were completely digested. The ability of intracellular C ampylobacter to remain viable after ingestion was tested by sorting individual ciliates and bacterial cells into C ampylobacter‐ selective media. C ampylobacter growth occurred in 15% (± 5 SE) of wells seeded with highly fluorescent ciliates, whereas only 4% (± 1) of wells seeded with free‐living C ampylobacter exhibited growth. A key advantage of this approach is that it is rapid and should be applicable to other phagocytotis studies.