Aktuelle Ergebnisse zur Feintypisierung von Salmonella Typhimurium aus Hackfleisch

Current results on the detailed typing of Salmonella Typhimurium
from minced meat. The aim of the study was to use PFGE to analyse
salmonella isolates from samples of minced meat taken from an
EU-approved abattoir and meat processing facility in the period
from January 2002 to January 2004. The results were compared with
data from previous analyses. Of the total of 350 minced meat
samples examined, 36 tested positive for salmonella (10.3 %). The
evaluation showed an increase in the number of samples testing
positive for salmonella in both summer and winter months. It was
remarkable that the samples which most frequently tested positive
came from minced meat produced on Tuesdays and Fridays. Detailed
typing of the isolates using PFGE was modified and optimised. Only
S. Typhimurium and S. Typhimurium var. Copenhagen were examined, as
these serovars had been most frequently isolated (51.4 % and 25.7 %
respectively), and have a prominent role to play in terms of
epidemiology. The macrorestriction enzymes Xba I and Spe I were
used. The results following restriction using Xba I were compared
with those from previous analyses. Restriction of all isolates
using Spe I served to verify the results. Six different restriction
patterns were found using Xba I; the majority of the isolates (87.5
%) could be classified in three groups. A comparison with the
results from previous analyses showed that two of the groups had
been discovered in the minced meat samples of the same facility
since 1996. The third group was discovered for the first time in
the course of this study. The fact that salmonella isolates with
identical macrorestriction patterns have been found in minced meat
samples of a production facility over a period of seven years
points to a persistent source of contamination which normal hygiene
measures have been unable to pick up. Consumer protection would be
considerably improved if this source could be detected and
eliminated.