Aktuelle Themen

Aktuelle Themen

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Harvey Harbach, Harry W. Palm
Risk reduction of potential Vibrio para­haemolyticus transfer via blue mussels ­(Mytilus edulis L.) into the consumer in the Baltic Sea Region
Reduzierung des Risikos der potentiellen Übertragung von Vibrio parahaemolyticus durch Miesmuscheln (Mytilus edulis L.) auf den Konsumenten in der Ostseeregion Blue mussels (Bivalvia) potentially accumulate Vibrio spp. and can transfer these ­pathogens into the consumer. Earlier studies dealt with the existence of V. para­haemolyticus in natural environments but no examinations under laboratory con­ditions exist on the influence of temperature onto accumulation and persistence in blue mussels under low salinity environments. The aim of this study was to design a reliable and practicable methodology to examine the presence of V. parahaemo­lyticus in blue mussels from the Baltic Sea and possibilities for decontamination. A static design was chosen, estimating the influence of temperature onto contami­nation and clearance kinetics. Blue mussels accumulated a similar amount of V. parahaemolyticus during 24 h with no significant difference at the chosen temperatures of 5, 10 and 20 °C. After transfer into clearance tanks, the numbers of bacteria ­decreased in all mussels for 72 h, but the amounts differed significantly between 5 °C to 10 °C and 10 °C to 20 °C. Highest reduction from initial 4.84x107 cfu/mg to 1.16x105 cfu/mg (72 h) was observed at 10 °C (about 0.2 % of initial value). The Baltic Sea offers opportunities for blue mussel production, especially in the context of ­Integrated Multi Trophic Aquaculture to reduce environmental impact of fish aquaculture. In the case of mussel infection, a clearance bath for 72 h under 10 °C can prevent possible transfer of V. parahaemolyticus into the consumer.

Hana Buchtová, Petr Maršálek, Ladislav Kašpar
Dynamics of the biogenic amines formation in sausages with 45 % of the common carp (Cyprinus carpio L.) meat
Dynamik der Bildung biogener Amine in Würsten mit 45 % Fleischanteil vom Karpfen (Cyprinus carpio L.) The aim was to compare the biogenic amines (BAs) content in sausages with different processing (Control/pork sausages, Fish/experimental sausages with 45 % carp meat/) and packaging characteristics (Air/Vacuum) stored for 30 days at 2 ± 2 °C. Samples were taken on the 1st day of production and during the experiment (Days 6, 9, 13, 16, 20, 23, 27 and 30). Measurement was based on high-performance liquid chromatography coupled with tandem mass spectrometry. The total BAs content (mg/kg) in unpacked (Fish/Air: 86.20 ± 2.83) and packed (Fish/Vacuum: 92.63 ± 4.53) sausages was higher than that in the pork sausages (Control/Air: 74.16 ± 2.04, Control/Vacuum: 75.60 ± 2.46). The greatest proportion of BAs (mg/kg) was made up of spermine (Fish/Air: 79.48 ± 2.59, Fish/Vacuum: 87.26 ± 4.78, Control/Air: 69.49 ± 2.00, Control/Vacuum: 70.73 ± 3.73). Histamine was present at a quantity of less than 0.5 mg/kg. Cadaverine, tryptamine and 2-phenylethylamine were not detected in any of the groups of samples.

Birce Mercanoglu Taban, Ömer Akineden, Sahar Karimihachehsoo, Madeleine Gross, Ewald Usleber
Enterotoxigenic Staphylococcus aureus in brined cheese from weekly street markets in Ankara, Turkey
Enterotoxinbildende Staphylococcus aureus in Salzlakenkäse aus dem mobilen Straßenverkauf in der Provinz Ankara, Türkei A total of 63 brined cheeses (30 white pickled cheeses, 33 Tulum cheeses) were ­randomly collected from informal market places such as weekly street markets in the province Ankara during a seven-month period, and quantitatively analysed for ­Staphylococcus (S.) aureus. S. aureus isolates obtained from these samples were analysed for staphylococcal enterotoxin (SE) genes by PCR, selected isolates were tested for SEA-SEE production by enzyme immunoassay. S. aureus was found in ­eleven (17.0 %) of cheese samples at levels between 9.5 × 102 and 5.0 × 106 cfu/g. All 22 S. aureus isolates were positive by PCR for one or more toxin genes (sea, sed, seg, sei, selj, sem, sen, seo, sep, ser and selu), forming three distinct toxin profiles. SEA or SED production was found for isolates from five samples, by enzyme immunoassay. Further characterization of isolates by macrorestriction analysis yielded three different pulsed-field gel electrophoresis (PFGE) profiles which corresponded well with SE gene profiles. Identical PFGE profiles were obtained for isolates from several alleged unique cheeses, purchased from different vendors in different markets, indicating a common source of production and disproving the claimed originality. These findings highlight the existence of health hazards related to consumption of traditional cheeses originating from such underregulated markets and the need to implement more intensive hygiene control measures.