Evaluation of Swab and Tissue Excision Methods for Recovering Microorganisms from Washed and Sanitized Beef Carcasses1,2

Abstract

Samples taken from dressed beef carcasses by swabbing surfaces or excising tissues were plated to produce counts of aerobic bacteria, Enterobacteriaceae, and Escherichia coli. Counts were compared to determine efficiencies of the two sampling methods. Excised tissues produced much higher counts than did swabs, especially when washed and sanitized carcasses were sampled. Percentages recovered by swabbing appeared to be influenced by characteristics of the area sampled on the carcass. Numbers of Enterobacteriaceae and E. coli recovered by swabbing washed and sanitized carcasses were usually too few to be countable, whereas excision usually produced countable plates. The excision sampling method permitted differentiation among treatment effects of washing and sanitizing.