Reference | Zhang2010 (10138)

Researchers conducted a series of experiments examining bacterial contamination rates in 50 beef products labeled as “grass-fed” versus 50 conventionally raised retail beef products. They measured several fecal contamination indicators as well as antimicrobial resistance profiles in Enterococcus spp. and E. coli isolates.

Conventionally raised and “grass-fed” labeled beef retail samples were collected from retail outlets in Illinois and Indiana between July 2008 and March 2009. A total of 50 conventional beef retail samples were collected from four retail outlets. The 50 retail beef samples labeled as “grass-fed” were collected from 10 sources representing both retail outlets as well as more direct markets (farm stores or farmers' markets).The conventional beef sample set included 34 solid cuts (e.g., steaks, stew meat, ribs, soup bones, etc.) and 16 ground beef samples. The grass-fed beef sample set included 33 solid cuts and 17 ground beef samples. Samples were tested for enterococcus and e coli. Of those which were positive, AMR test was conducted on randomly chosed positive meat samples..

AST Method: None

Reference explicitly reports AST breakpoints: True

Reference reports using a MIC table: True