Abstract

Title: Is Simonsiella a single cell organism? Harold Tvedten Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala Sweden. All experienced cytologists have seen Simonsiella on stratified squamous epithelial cells from the mouth of dogs and other species. Nyby (1977) reported finding Simonsiella on cells from the palate of 66 of 67 dogs. Dogs, cats and people each have different types of Simonsiella in their oral cavity. Burkhard and Millward (Page 126, Chapter 5 of Raskin and Meyer’s Canine and Feline Cytology 2010) defined Simonsiella as ”large, rod-shaped bacteria that align in a row after division resulting in a distinctive pattern that resembles stacked coins.” Most definitions describe bacteria as single cell organisms. Is Simonsiella a single-cell, rod-shaped organism in a chain? During this presentation Tvedten will attempt to redefine Simonsiella to veterinary cytologists as a flat, oval, multicellular organism. About 12-19 cells form subunits called trichromes. Individual cells become shorter (less wide) at the ends of the trichrome to give it a more oval shape. Simonsiella’s trichrome is not a cylinder that resembles stacked coins but a flat oval structure with dorsal-ventral differentiation. Trichrome’s ventral side has a fibrillar fringe by which Simonsiella binds to a mucosal cell’s surface and allows one or more trichromes to glide along the surface of an epithelial cell. The dorsal side has somewhat of a capsule. Electron microscopy shows open connections between ”individual” cells (Pangborn 1977), which may allow communication among cells. The trichrome looks and acts as a multicellular organism and not simple a chain of rods. It does not fit the routine definition of a single cell bacterium

Published in

Publisher: European College of Veterinary Clinical Pathology

Conference

13th Conference of the ESVCP/ECVCP

SLU Authors

• Tvedten, Harold

  • Department of Clinical Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Animal and Dairy Science
Veterinary Science


Permanent link to this page (URI)

https://res.slu.se/id/publ/34845