Effects of Experience with Swabbing Procedures on the Numbers of Bacteria Recovered from Carcasses by Swabbing with Sponges†

Abstract

Each carcass in groups of 25 pig, cattle, or bison carcasses was sampled by five people: two or three people experienced with carcass sampling and two or three without previous experience. Each person sampled a different randomly selected site on a dressed carcass side by swabbing an undelimited area of approximately 100 cm2 with a moistened synthetic sponge. The numbers of aerobic bacteria, coliform bacteria, and Escherichia coli recovered from each sample were determined. The mean log and log mean values were calculated for each set of 25 counts for each group of bacteria from pig carcasses and each set of 25 aerobic counts from cattle and bison carcasses from the samples obtained by each person. Values for the log of the total number recovered were calculated for all the sets of counts from samples obtained by each person. Most of the corresponding statistics for each set of counts of the same type for samples obtained by five people from the same group of carcasses differed by less than 0.5 log unit. These findings indicate that the numbers of bacteria recovered from carcasses by swabbing with sponges are unlikely to differ substantially as a result of samples being collected by different people using the same procedure.