The Journal of Medical Microbiology, Vol 24, Issue 3 205-218, Copyright © 1987 by Society for General Microbiology
Surface properties of Yersinia species and epithelial cell interactions in vitro by a method measuring total associated, attached and intracellular bacteria
D. A. Schiemann, M. R. Crane and P. J. Swanz
Department of Microbiology, Montana State University, Bozeman 59717.
A procedure was developed for enumeration of total associated, attached and
intracellular bacteria after interaction of Yersinia spp. with epithelial
cells in vitro. Isogenic cultures of Y. enterocolitica grown at 25 degrees
C had greater affinity for epithelial cells (Henle, HeLa and Vero) than for
polystyrene, and they invaded the cells. Y. kristenseni and Y. intermedia
showed less attachment to either surface and were non-invasive. The degree
of attachment to cells and invasion by Y. enterocolitica was related to
number of bacteria added and interaction time, whereas attachment to
polystyrene occurred rapidly and did not change. Y. enterocolitica was more
hydrophobic when grown at 35 degrees C than at 25 degrees C according to
partitioning in a biphasic dextran-polyethylene glycol system, and attached
strongly to both polystyrene and epithelial-cell monolayers. Y. kristenseni
grown at 25 degrees C was also hydrophobic but did not have the same
attachment properties. Y. kristenseni and Y. intermedia showed slightly
reduced electrostatic interactions with the anion exchangers DEAE-Sepharose
and DEAE-Trisacryl. Attachment of Y. enterocolitica to epithelial cells
probably involves non-specific surface properties that are not entirely
explicable by hydrophobic and electrostatic interactions, whereas invasion
of epithelial cells appears to resemble "receptor-mediated endocytosis".
