[Example of the concentration of salmonellae in the environment]

During a period of 3 years the occurrence of Salmonellas was cleared up on depots for refuse of households around Berlin. The investigations were carried out by susceptible fractionated enrichment in Medium of Rappaport/Vassiliadis. 15.1% of samples were positive (77 out of 511). Most Salmonellas wer detected in soil samples contaminated with feces of birds. The isolation rate reached his maximum during autumn and winter, when great bird herds lived on the depots. Mainly S. typhimurium, S. saint paul and S. enteritidis were found. S. enteritidis LT 17 (Colindale) was isolated first time in former East Germany. Diseased children of Berlin (West) were the source for contamination of refuse of households and wild birds (crows, gulls) with this Lysotype. During 51 months dissemination of Salmonellas in 4 contaminated feedstuff yeast and animal meal plants was examined. Salmonella were found in 12.02% of samples of feedstuff yeast (2047) and 6.2% of samples of animal meal (337). Characteristically was the seasonal distribution during winter and early spring and the persistence of the same serotypes for years. Recontamination by the environment was the main reason for the occurrence of Salmonella. Regular examination of filter dust samples of all production units was a very effective way for detection of Salmonella contamination in feed plants. S. enteritidis was demonstrated in the environment of an animal meal factory 18 months after his shutdown.