[A multi-pathogen selective enrichment broth for simultaneous growth of Salmonella enteritidis, Staphylococcus aureus, and Listeria monocytogenes]

Abstract

Objective: A selective enrichment broth (SSL) was formulated to allow simultaneous growth of Salmonella enteritidis, Staphylococcus aureus, and Listeria monocytogens.

Methods: Suitable additive agents were selected by single factor experiment, the enrichment effect of the broth for the three pathogens were evaluated by conventional detection method and real-time PCR.

Results: A selective enrichment broth, SSL, was obtained by adding the selective agents, including nalidixic acid, lithium chloride, and potassium tellurite, in the basic broth, and sodium pyruvate and mannitol as the supplemented elements. Recovery of three target pathogens in SSL was obtained within 24 h of incubation at 37 degrees C, yielding cell dnesities of 10(7) - 10(8) CFU/mL. Meanwhile, SSL broth effectively inhibited the growth of non-target organisms. 710 samples were detected by SSL with real-time PCR, and there is no error report.

Conclusion: SSL is demonstrated to be a promising new multiplex selective enrichment broth for simultaneous detection of the three most prominent foodborn pathogens by multipathogen detection on a single assay platform.