ERP Micro December 2019

Raw Beef Trim – 375 g Test Portion (Unpaired) Method Comparison

Of the 20 low inoculation level replicates of the Assurance® GDS for E . coli O157:H7 Tq assay, by manual processing, there were 13 presumptive positives and 13 confirmed positives following the traditional confirmation procedures. There were 16 confirmed positives for the reference method. Of the 5 high inoculation level replicates, there were 5 presumptive positives and 5 confirmed positives following the traditional confirmation procedures. There were 5 confirmed positives for the reference method. MPN analysis of the inoculation levels determined the concentration of E . coli O157:H7 for the low level was 1.42 MPN/test potion and 2.93 MPN/test potion for the high level. All uninoculated samples were negative. Results for the processing by the PPMX DNA extraction procedure were the same as by manual processing. The POD analysis between the GDS EHEC presumptive (POD CP ) and confirmed results (POD CC ) indicated that there was no statistically significant difference at the 5% level for both methods at 8 h of enrichment. The POD analysis between the GDS EHEC methods presumptive (POD C ) and reference method confirmed (POD R ) results indicated that there was not a statistically significant difference at the 5% level for both methods. Frozen Finely Textured Beef – 375 g Test Portion (Unpaired) Method Comparison Results for the processing by the PPMX DNA extraction procedure were the same as by manual processing (see FTB Method Comparison , previous section, for recovery). The POD analysis between the GDS EHEC methods presumptive (POD C ) and reference method confirmed (POD R ) results indicated that there was a statistically significant difference at the 5% level for both methods (see Discussion , previous section). Carcass Cloths (Unpaired) Method Comparison