Abstract :
A monitoring study was performed for the presence of Salmonella spp., Listeria monocytogenes and sulphite-reducing Clostridium spores in (internationally) traded dry-salted natural hog and sheep casings. Two hundred and fourteen consignments were examined for Salmonella spp. and L. monocytogenes, and 138 for the Clostridium spores.
None of the 214 sampled consignments (25 g amounts investigated) yielded Salmonella spp., or L. monocytogenes.
Differential reinforced clostridial medium was effective in detecting the presence of sulphite-reducing clostridia. Iron sulphite agar (ISA) overall showed higher clostridia counts as compared to differential reinforced clostridial agar (DRCA). The maximum spore counts obtained on DRCA and ISA were 17.5 and 2500 cfu g−1, respectively. From the casings from China, 3 (of 35 hog consignments) and 7 (of 22 sheep) showed spore counts above 100 cfu g−1. From the remaining 81 samples, originating from Netherlands, New Zealand and UK, none showed a count above 100 cfu g−1.
The relevance of the presence of sulphite-reducing Clostridium spores for the manufacture of various meat products is discussed. It is recommended that determination of the Clostridium strains present is carried out and their properties investigated in relation to the manufacture of meat products, since some of the strains may be potentially pathogenic and/or able to spoil products.
