Effect of temperature on the survival of Haemophilus parasuis in physiological saline.

The survival of Haemophilus parasuis in physiological saline and in sodium phosphate buffered saline (PBS) at various temperatures was investigated and compared with that of H. pleuropneumoniae, Pasteurella multocida, and Escherichia coli. When placed in physiological saline, H. parasuis became undetectable at 42 degrees C within one hour, at 37 degrees C within 2 hours, and at 25 degrees C within 8 hours, but decreased slightly in amount at 5 degrees C for 8 hours. It showed the same tendency when placed in PBS. In the same condition, H. plueropneumoniae decreased more slowly in amount than H. parasuis, P. multocida was much more stable than H. parasuis, and E. coli hardly decreased even at 42 degrees C for 8 hours.