Comparative study on the high pressure inactivation behavior of the Shiga toxin-producing Escherichia coli O104:H4 and O157:H7 outbreak strains and a non-pathogenic surrogate.

摘要: Enterohemorrhagic Escherichia coli strains cause each year thousands of illnesses, which are sometimes accompanied by the hemolytic uremic syndrome, like in 2011 outbreak Germany. For preservation thermal pasteurization is commonly used, can unwanted quality changes. To prevent this high pressure treatment a potential alternative. Within study, strain O104:H4, an O157:H7 and non-pathogenic (DSM1116) were tested. The cells treated buffer (pH 7 pH 5) carrot juice 5.1) temperature range 0.1e500 MPa 20e70 � C. Flow cytometry was used to investigate impact on cell structures DSM1116. Both pathogenic had much higher resistance than nonpathogenic surrogate. Further, cultivated at lower pH-value showed stability, presumably due variations membrane composition. This confirmed for DSM1116 flow cytometry. Cells 5 stronger ability retain their but rates permeabilization pressures <200 compared 7. These lowest rate around 125 MPa, possibly denoting that fatty acid composition fluidity contribute stabilization phenomenon.