A morphological characterization of Borrelia anserina.
The morphology and ultrastructure of two strains of B. anserina were investigated by electron microscopy of negatively stained and ultrathin sectioned cells. One was a cultivable strain originally isolated in the USA and the other was originally isolated in Nigeria and maintained in chickens. The cells were regularly helical, 9-21 µm long and 0.22-0.26 µm wide with a helix wavelength of about 1.7 µm. The cells were surrounded by a surface layer and appeared to divide by binary fission. The structure of the cells from each of the 2 strains was identical except that those of the USA strain possessed 7 flagella inserted at each end and those from the Nigerian strain had 8.