|Suo, Yujuan - Shanghai Academy Of Agricultural Sciences|
|Gao, Shigang - Shanghai Academy Of Agricultural Sciences|
|Xie, Yanping - Collaborator|
|Qu, Yang - Shanghai Academy Of Agricultural Sciences|
|Shen, Yuanyuan - Shanghai Academy Of Agricultural Sciences|
|Zhou, Changyan - Shanghai Academy Of Agricultural Sciences|
Submitted to: Journal of Food Safety
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2017
Publication Date: 8/3/2017
Citation: Suo, Y., Gao, S., Xie, Y., Liu, Y., Qu, Y., Shen, Y., Zhou, C. 2017. A multi-pathogen selective enrichment broth for simultaneous growth of Salmonella enteria, Escherichia coli O157:H7 and Shigella flexneri. Journal of Food Safety. doi:10.1111/jfs.12388. Interpretive Summary: Foodborne pathogens, including Salmonella, Shigella, and Escherichia coli are important human pathogens, therefore, accurate and rapid detection of these pathogens is very critical. Foodborne pathogens need to reach a certain level of growth in food samples before they can be detected. Normally, different media are needed to meet the growth requirements for different foodborne pathogens to reach appropriate levels for detection. In this report, a selective enrichment medium was developed to allow enrichment of the three pathogens simultaneously. Thus, this newly developed medium is very useful for more rapid and cost-effective detection of these pathogens by the food industry and regulatory agencies.
Technical Abstract: Salmonella, Shigella, and Escherichia coli O157:H7 contaminate similar types of food and all three can cause foodborne disease. Traditional microbiological enrichment broths to detect these pathogens are different in terms of their composition, which limits the application of multi-pathogen detection in a single-assay format. The objective of this study was to develop a selective enrichment broth for simultaneous enrichment of Salmonella Enteritidis, E. coli O157:H7, and S. flexneri (SES). Bile salts No. 3, potassium tellurite, novobiocin sodium salt, and lithium chloride were used as the selective agents. In individual growth trials, the target pathogens were able to grow in SES to levels as high as 9 log(10) colony-forming units (CFU/mL) after 24 h incubation at 37 deg C with 10-100 CFU/mL of initial inoculation concentration. In the simultaneous growth trial, the 3 combined target pathogens showed similar growth rates. The results showed that SES could support the successful simultaneous enrichment of the 3 target pathogens, and it showed inhibition of the growth of non-target bacteria. Using artificially contaminated raw pork, the 3 target pathogens grew equally well in SES and were detected using multiplex PCR targeting genes specific for each pathogen. In summary, SES was shown to be a promising new multiplex selective enrichment broth.