COLONIAL VARIATION OF PASTEURELLA HAEMOLYTICA ISOLATED FROM SHEEP

Abstract

Two types of P. haemolytica, distinguishable by colonial characteristics, crystal violet uptake, and serological properties, were recovered from lambs. They are stable in culture and show different degrees of pathogenicity for mice. A difference, possibly the only one between them, consists of a surface substance, present in abundance in the S type and relatively deficient in the R type of cell.