When it comes to food safety incidents, the majority of people gather their brows into a frown. Indeed, food safety has aroused public attention worldwide for a long time; particularly the contamination of foodborne pathogens is a big issue in this area. China has huge pork consumption compared to other countries; the safety and quality of pork products have raised particular attention from the scientists, government and enterprises. They have made great efforts in their own aspects to control the contamination in pork products. Of particular importance, the control of foodborne pathogen infection in swine production is a forward-looking and practical strategy.

Salmonella enterica serovar Typhimurium DT104 is a foodborne pathogen to human and other mammals, which is also the most common serovar/pathotype of Salmonella detected in China and Western Countries’ pig farms. Control of Salmonella infection in food animals is important but challenging. Probiotics have been suggested as a possible approach; however, only limited probiotic bacteria (e.g., lactobacilli) have been reported to reduce Salmonella infection in animals, including pigs and chickens.

Dr. YIN Fugui from Institute of Subtropical Agriculture, Chinese Academy of Sciences（ISA） and his foreign colleagues from Guelph Food Research Center, Agriculture & Agri-Food Canada have isolated dozens of lactic acid-producing bacteria (mainly are Lactobacillus) and pre-screened them on the nematode Caenorhabditis elegans (C. elegans) model challenged with Salmonella Typhimurium DT104. Several Lactobacillus strains exhibited promising probiotic activities as they could protect the C. elegans from Salmonella Typhimurium DT104 infection caused death. To further verify if such probiotic characters could be worked in livestock, they have conducted several challenge trials with the same pathogenic strain in pigs fed with newly isolated Lactobacillus strains fermented feed.

Researchers discovered that they inoculated Lactobacillus (L. zeae and L. casei) became the first predominant strains in the fermented feed. The fermented feed appeared to benefit pigs in combating Salmonella infection. Particularly, L. casei-fermented feed was more effective in reducing pig diarrhea and intestinal burden of Salmonella, while L. zeae –fermented feed was able to lower more local inflammatory/systemically acute-phase responses and Salmonella organ invasion.

This research was supported by Agriculture and Agri-Food Canada, University of Guelph-Ontario Ministry of Agriculture and Food Research Partnership Program as well as the Natural Sciences and Engineering Research Council of Canada.

The study entitled “Reduction of Salmonella enterica Serovar Typhimurium DT104 infection in experimentally challenged weaned pigs fed a Lactobacillus-fermented feed” has been published in Volume 11, Issue 8, August 2014 of Foodborne Pathogens and Disease, details could be found at http://dx.doi.org/10.1089/fpd.2013.1676