Prevalence of Listeria in Chinese food products from 13 provinces between 2000 and 2007 and virulence characterization of Listeria monocytogenes isolates.

Listeriosis is a severe disease with high mortality rate, especially in immunosuppressed individuals. The causative organism Listeria monocytogenes is primarily transmitted to humans through contaminated foods. To gain an understanding of the prevalence of Listeria in Chinese food products, we reviewed relevant papers from journals published in China from 2000 to 2007. The average recovery rate of Listeria spp. was 3.7% (0.1-7.7%) in all food categories in 13 provinces, with raw meat being the leading source. L. innocua (28.9%, 271/937) and L. monocytogenes (25.3%, 237/937) were more commonly isolated, both at higher proportion in all food types. Subtyping schemes in three laboratories in different provinces revealed that the majority of the L. monocytogenes isolates belonged to lineage II (67.1%), followed by lineage I at 31.6%, including the pathogenic serovars 1/2a, 1/2b, and 4b isolates. Lineage III isolates comprising the low-pathogenic serovar 4a were rare. Knowledge of the prevalence of Listeria in various food products in different regions of China may be useful for developing intervention strategies for control of contaminations along the production chains.