Microbial quality of liquid egg and salmonella infection status in Japan

Aerobic bacteria counts and contamination with Salmonella were investigated in a total of 1,327 samples of commercial liquid egg in 1992-2002. Salmonella was isolated from 8.1% of the samples, and Salmonella contamination was found in 1.7% of even the pasteurized liquid egg samples. The major Salmonella serotype was Enteritidis from more than 50% of the contaminated liquid egg samples. In addition, the aerobic bacteria counts in Salmonella-positive liquid eggs were significantly higher than those of Salmonella-negative samples. However, Salmonella was detected in liquid egg in which the aerobic bacteria counts were in the range of 10(2) to 10(6) cfu/g. Furthermore, foodborne outbreaks of Salmonella infections associated with liquid egg were analyzed. Liquid eggs should be carefully treated to avoid the possibility of Salmonella contamination. Adequate supply of pasteurized liquid eggs and controls to prevent re-contamination are needed.