Total Collaborative Study Protocol_Solus One Salmonella v1 1

considered acceptable. 

For the matrix study evaluation of the candidate Solus One  Salmonella method, a  Salmonella Agona 

ATCC 51957 (for raw beef trim matrix), a  Salmonella Enteritidis ATCC 13076 (for pasteurized liquid egg 

matrix), a  Salmonella Virchow ATCC 51955 (for raw salmon fillet matrix), a  Salmonella Heidelberg ATCC 

8326 (for shredded cheddar cheese matrix), a  Salmonella Muenchen ATCC BAA‐1594 (for bagged 

Romaine lettuce matrix), a  Salmonella  Senftenberg ATCC 43845 (for non‐fat dry milk powder matrix), a 

Salmonella Typhimurium ATCC 14028 (for stainless steel environmental surface matrix) and Salmonella

Montevideo ATCC 8387 (for plastic environmental surface matrix) inoculums were cultured by 

transferring a single colony from trypticase soy agar with 5% sheep blood (SBA) into BHI broth for 24 ± 2 

h at 35 ± 2°C to obtain stationary phase cell densities. The  Salmonella  starter cultures were 

subsequently diluted in BHI broth, added to the respective matrixes and subsequently mixed. At these 

low and high inoculum levels, fractional positives or consistently positive results at the time of sampling 

were anticipated. 

Where co‐inoculation was required, a Citrobacter freundii ATCC 8090 strain was cultured in BHI 

broth for 22 ± 2 h at 35 ± 1°C and diluted to ten times the level of the  Salmonella  strain (890–3700 

CFU/test area). 

100 g pasteurized liquid egg and 375 g raw beef trim or NFDM test portions were prepared by 

mixing together 25 g of inoculated test product with 75 g or 350 g of un‐inoculated test product 

respectively. 

The level of  Salmonella  in the low and high level inoculum for both 25 g and 100 g test portions 

were determined by Most Probable Number (MPN) on the day of analysis. Each test portion was 

enriched with the respective reference method enrichment (FDA/BAM Ch. 5 or MLG 4.09) and analyzed 

by the reference method procedure. The number of positives from the 3 test levels were used to

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