Impact of routine sanitation on Zone 3 microbiome in a fresh-cut produce processing facility

Authors: GU, GANYU - Virginia Tech; OTTESEN, ANDREA - Food And Drug Administration(FDA); BOLTEN, SAMANTHA - University Of Maryland; WANG, LAN - Shenyang Agricultural University; Luo, Yaguang - Sunny; RIDEOUT, STEVEN - Virginia Tech; LYU, SHUXIA - Shenyang Agricultural University; Nou, Xiangwu

Submitted to: International Journal of Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2019
Publication Date: 2/2/2019
Citation: Gu, G., Ottesen, A., Bolten, S., Wang, L., Luo, Y., Rideout, S., Lyu, S., Nou, X. 2019. Impact of routine sanitation on Zone 3 microbiome in a fresh-cut produce processing facility. International Journal of Food Microbiology. 294:31-41. https://doi.org/10.1016/j.ijfoodmicro.2019.02.002 .
DOI: https://doi.org/10.1016/j.ijfoodmicro.2019.02.002

Interpretive Summary: Contamination of fresh produce by foodborne pathogens could be originated at various stages of production, including field growth and post harvest processing. The food processing environment harbors distinct microbial communities which can have profound effect on the survival and persistence of potential contaminating foodborne pathogens. In this study, we investigated the microbiome in one fresh-cut produce processing facility. The identities and relative abundance of bacterial species on a variety type of environmental surfaces were determined before and after routine sanitation. The results indicated bacterial populations were more consistently and significantly reduced from surfaces on the production floor after sanitation compared to the peripheral surfaces. We identified a core residential microbiota (a collection of bacterial species) abundantly presenting in the processing facility. This study benefits the research community for better understanding the microbial ecology in food processing environment, and fresh produce processors for knowing the microbiome in the processing facilities.

Technical Abstract: Indigenous bacterial populations in fresh-cut produce processing facilities can have a profound effect on the survival and proliferation of inadvertently contaminating foodborne pathogens. In this study, environmental samples were collected from a variety of zone 3 sites in a processing plant before and after daily routine sanitation. Viable mesophilic aerobic bacteria population was evaluated using both culturing method and quantitative real-time PCR (qPCR) after propidium monoazide treatment. Zone 3 surface microbiota were analyzed using 16S rDNA amplicon sequencing with the Qiime2 bioinformatic pipeline. Over 8,000 bacterial species across 4 major phyla were identified in Zone 3 microbiomes in the processing facility. Overall, effective bacterial reduction was observed at the sampling sites on the production floor, while sanitation effect on peripheral surfaces was less evident. Effective sanitation resulted in both quantitative and qualitive shifts of Zone 3 microbiota. Several species were highly abundant at multiple sample sites for both winter and summer samplings. Based on the spatial and temporal distribution of the most abundant species, a Zone 3 core microbiome in the processing facility was tentatively described to included Cupriavidus sp., Pseudomonas sp., Ralstonia sp., Arthrobacter psychrolactophilus, Pseudomonas veronii, Stenotrophomonas sp., and an unknown species of the family Enterobacteriaceae.