[Bacteriological study of fresh, preserved, damaged and contaminated pig spleens]

Since the amendment of the Meat Inspection Act as on January 1, 1979, only the spleen is used as an indicator organ to detect bacteraemia in bacteriological examinations. The spleens should be handled carefully during slaughter, inspection, storage, transportation and laboratory testing in order to prevent false positive results of bacteriological examination caused by errors of inoculation, damage, contamination and unduly high storage temperatures. Bacteria could not be isolated from 86.2 per cent of 399 directly examined spleens of clinically normal pigs. Positive cases may have been due to acute bacteraemia in which the primary source of infection escaped notice, transient bacteraemia or errors of inoculation. Moreover, examination of damaged or contaminated spleens and spleens stored at too high temperatures showed that the usual method of sterilisation of the splenic surface singing is inadequate in some cases. In view of the fact that storage at 4 degrees C was not found to affect the results of bacteriological examination, the spleens which are to be examined should be intensively chilled immediately after slaughter.