Biosurfactant Produced by Salmonella Enteritidis SE86 Can Increase Adherence and Resistance to Sanitizers on Lettuce Leaves (Lactuca sativa L., cichoraceae).

Eliandra M Rossi,Marília Kochhann,Diana H Sarzi,Luniele Beilke,Eduardo C Tondo

doi:10.3389/fmicb.2016.00009

Abstract

Salmonella Enteritidis SE86 is an important foodborne pathogen in Southern Brazil and it is able to produce a biosurfactant. However, the importance of this compound for the microorganism is still unknown. This study aimed to investigate the influence of the biosurfactant produced by S. Enteritidis SE86 on adherence to slices of lettuce leaves and on resistance to sanitizers. First, lettuce leaves were inoculated with S. Enteritidis SE86 in order to determine the amount of biosurfactant produced. Subsequently, lettuce leaves were inoculated with S. Enteritidis SE86 with and without the biosurfactant, and the adherence and bacterial resistance to different sanitization methods were evaluated. S. Enteritidis SE86 produced biosurfactant after 16 h (emulsification index of 11 to 52.15 percent, P < 0.05) and showed greater adherence capability and resistance to sanitization methods when the compound was present. The scanning electron microscopy demonstrated that S. Enteritidis was able to adhere, form lumps, and invade the lettuce leaves’ stomata in the presence of the biosurfactant. Results indicated that the biosurfactant produced by S. Enteritidis SE86 contributed to adherence and increased resistance to sanitizers when the microorganism was present on lettuce leaves.

Highlights

Salmonella Enteritidis SE86 is a recognized food pathogen responsible for several foodborne disease (FBD) outbreaks in Southern Brazil (Geimba et al, 2004; Oliveira et al, 2009; Tondo and Ritter, 2012; Capalonga et al, 2014; Tondo et al, 2015)
During the preparation of the inoculum in minimal medium, SE86 produced emulsifier (EI24 46%); after 120 h, the IE24 decreased to 3%, probably because the energy sources were depleted
SE86 without biosurfactant was completely inactivated by 50 ppm sodium hypochlorite in 15 min, while with biosurfactant, the microorganism survived for 30 min

Summary

Introduction

Salmonella Enteritidis SE86 is a recognized food pathogen responsible for several foodborne disease (FBD) outbreaks in Southern Brazil (Geimba et al, 2004; Oliveira et al, 2009; Tondo and Ritter, 2012; Capalonga et al, 2014; Tondo et al, 2015). Several studies have been carried out taking into account the importance of this pathogen with the aim of understanding the reasons that it continues to be an important foodborne pathogen in this region since 1999 (Geimba et al, 2004; Capalonga et al, 2014; Tondo et al, 2015). Biosurfactant Produced by Salmonella Enteritidis SE86 hypochlorite at 200 and 400 ppm (Machado et al, 2010). The characteristics and functions of this compound have not been studied yet

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Conclusion