The occurrence of Listeria monocytogenes is associated with built environment microbiota in three tree fruit processing facilities

Xiaoqing Tan,Xiaoqing Tan,Dumitru Macarisin,Luke Laborde,Jasna Kovac,Yi Chen,Taejung Chung

doi:10.1186/s40168-019-0726-2

Xiaoqing Tan, Xiaoqing Tan + Show 5 more

Open Access

https://doi.org/10.1186/s40168-019-0726-2

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Abstract

BackgroundMultistate foodborne disease outbreaks and recalls of apples and apple products contaminated with Listeria monocytogenes demonstrate the need for improved pathogen control in the apple supply chain. Apple processing facilities have been identified in the past as potential sources of persisting L. monocytogenes contamination. In this study, we sought to understand the composition of microbiota in built apple and other tree fruit processing environments and its association with the occurrence of the foodborne pathogen L. monocytogenes.ResultsAnalysis of 117 samples collected from three apple and other tree fruit packing facilities (F1, F2, and F3) showed that facility F2 had a significantly higher L. monocytogenes occurrence compared to F1 and F3 (p < 0.01). The microbiota in facility F2 was distinct compared to facilities F1 and F3 as supported by the mean Shannon index for bacterial and fungal alpha diversities that was significantly lower in F2, compared to F1 and F3 (p < 0.01). Microbiota in F2 was uniquely predominated by bacterial family Pseudomonadaceae and fungal family Dipodascaceae.ConclusionsThe composition and diversity of microbiota and mycobiota present in the investigated built food processing environments may be indicative of persistent contamination with L. monocytogenes. These findings support the need for further investigation of the role of the microbial communities in the persistence of L. monocytogenes to support the optimization of L. monocytogenes control strategies in the apple supply chain.

Highlights

Multistate foodborne disease outbreaks and recalls of apples and apple products contaminated with Listeria monocytogenes demonstrate the need for improved pathogen control in the apple supply chain
It is becoming increasingly evident that microbiota found in food production and processing environments plays a role in pathogen survival and persistence and that microbiota needs to be taken in consideration when assessing the effectiveness of pathogen control strategies [16]
Samples collected from facility F2 had higher occurrence and level of L. monocytogenes compared to those collected from F1 and F3 A total of 117 environmental samples were tested for the presence of L. monocytogenes using the Food and Drug Administration (FDA) Bacteriological analytical manual (BAM) enrichment protocol

Summary

Introduction

Multistate foodborne disease outbreaks and recalls of apples and apple products contaminated with Listeria monocytogenes demonstrate the need for improved pathogen control in the apple supply chain. We sought to understand the composition of microbiota in built apple and other tree fruit processing environments and its association with the occurrence of the foodborne pathogen L. monocytogenes. Tan et al Microbiome (2019) 7:115 antimicrobial treatments [10,11,12,13] These studies provided valuable insight into the ability of sanitizers to inhibit the growth of L. monocytogenes in monocultures [10, 14]; they failed to adequately model the complex biotic environmental conditions found in postharvest food processing built environments [15, 16]. It is becoming increasingly evident that microbiota found in food production and processing environments plays a role in pathogen survival and persistence and that microbiota needs to be taken in consideration when assessing the effectiveness of pathogen control strategies [16]

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