Effect of a previous infection with a low virulent Mycoplasma, hyopneumoniae strain on the course of an infection with a highly virulent M. hyopneumoniae strain

摘要

Mycoplasma hyopneunoniae is the primary cause ot enzootic pneumonia. Apart from management and housing conditions, the infection pattern and severity of the disease have been shown to be determined by the virulence of the M. hyopneumoniae strain (1).The aim of this study was to evaluate the possible protection induced by infection with low virulent isolates of M. hyopneumoniae against challenge infection with a highly virulent strain.