Susceptibility of foodborne pathogens to sanitizers in produce rinse water and potential induction of viable but non-culturable state. (June 2020)

• Record Type: Journal Article
• Authors: Gu, Ganyu; Bolten, Samantha; Mowery, Joseph; Luo, Yaguang; Gulbronson, Connor; Nou, Xiangwu
• Is Part Of: Food control. Volume 112(2020)
• Publication Date: 2020-06
• Subjects: Spinach -- Lettuce -- Shiga-toxigenic Escherichia coli -- Salmonella enterica -- Listeria monocytogenes -- Chlorine -- Peracetic acid -- Viable but non-culturable; Food -- Quality -- Periodicals; Food -- Analysis -- Periodicals; Food handling -- Periodicals; Food industry and trade -- Quality control -- Periodicals; Aliments -- Industrie et commerce -- Qualité -- Contrôle -- Périodiques; Aliments -- Qualité -- Périodiques; Aliments -- Analyse -- Périodiques; Hygiène alimentaire -- Périodiques; Food -- Analysis; Food handling; Food -- Quality; Periodicals; Electronic journals; 664.07
• DOI: 10.1016/j.foodcont.2020.107138
• Languages: English
• ISSNs: 0956-7135

Abstract

Abstract: Chemical sanitizers are commonly used for fresh produce washing to reduce potential presence of foodborne pathogens and spoilage bacteria, and to prevent cross-contamination. In this study, we evaluated the susceptibility of foodborne pathogens, including Shiga-toxigenic Escherichia coli, Salmonella enterica, and Listeria monocytogenes, to free chlorine (FC) and peracetic acid (PAA) in spinach and romaine lettuce rinsates as simulated leafy green wash water. All inoculated pathogens exhibited notably enhanced tolerance (over 2 log of increased recovery) to FC, but not to PAA, when treated in fresh produce rinsates in comparison to that in sterile water. Both FC and PAA effectively inactivated the inoculated foodborne pathogens, rendering them undetectable after 30 s exposure to 10 mg/L FC or 30 mg/L PAA, by selective plating or non-selective enrichment. However, potentially viable cells for all the inoculated foodborne pathogens were detected by PMA-qPCR, especially in wash water samples treated with PAA at concentrations up to 50 mg/L. While laser confocal microscopy after differential staining suggested significant presence of viable but non-culturable (VBNC) populations in PAA treated wash water samples, resuscitation in vitro of the potential VBNC cells was not achieved. This study provides scientific data to better understand the risks of potential VBNC foodborne pathogens during fresh produce washing. Highlights: Pathogen sanitizer susceptibility in produce wash water assessed. Culture-dependent and -independent detections showing great discrepancies. Potentially sanitizer induced VBNC explored. Resuscitation of potential VBNC populations no achieved in vitro .