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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Meat Safety and Quality » Research » Publications at this Location » Publication #412383

Research Project: Holistic Tactics to Advance the Microbiological Safety and Quality of the Red Meat Continuum

Location: Meat Safety and Quality

Title: Impact of intense sanitization procedures on bacterial communities recovered from floor drains in pork processing plants

item Bosilevac, Joseph - Mick
item Guragain, Manita
item BARKHOUSE, DARRYLL - Biomerieux, Inc
item VELEZ, SARAH - Biomerieux, Inc
item KATZ, TATUMS - Orise Fellow
item LU, GUOQING - University Of Nebraska
item Wang, Rong

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/23/2024
Publication Date: 5/20/2024
Citation: Bosilevac, J.M., Guragain, M., Barkhouse, D.A., Velez, S.E., Katz, T., Lu, G., Wang, R. 2024. Impact of intense sanitization procedures on bacterial communities recovered from floor drains in pork processing plants. Frontiers in Microbiology. 15. Article 1379203.

Interpretive Summary: Pathogens like Salmonella or spoilage organisms can live in biofilms in pork processing plants. Pork processors perform intense sanitization of their facilities one or two times per year to control bacteria that can cause food safety and shelf-life problems that is more extensive than daily sanitation procedures. The effect of these intense sanitization procedures was determined at two pork plants by collecting samples immediately before and for weeks following an intense sanitization. The intense sanitization disrupted the types of bacteria found and how strong a biofilm they could form. Over time, as more bacteria recovered from the treatment, mixed results were found that varied between each plant and the location where of the sample was collected. The results provide new information on how intense sanitization changes the bacteria that are present in pork processing environments.

Technical Abstract: Background: Pork processing plants in the United States (US) cease operations for 24–48 h every six or twelve months to perform intense sanitization (IS) using fogging, foaming, and further antimicrobial treatments to disrupt natural biofilms that may harbor pathogens and spoilage organisms. The impact such treatments have on short-term changes in environmental microorganisms is not well understood, nor is the rate at which bacterial communities return. Methods: Swab samples were collected from floor drains to provide representative environmental microorganisms at two US pork processing plants before, during, and after an IS procedure. Samples were collected from four coolers where finished carcasses were chilled and from four locations near cutting tables. Each sample was characterized by total mesophile count (TMC), total psychrophile count (TPC), and other indicator bacteria; their biofilm-forming ability, tolerance of the formed biofilm to a quaternary ammonium compound (300 ppm, QAC), and ability to protect co-inoculated Salmonella enterica. In addition, bacterial community composition was determined using shotgun metagenomic sequencing. Results: IS procedures disrupted bacteria present but to different extents depending on the plant and the area of the plant. IS reduced TPC and TMC, by up to 1.5 Log10 CFU only to return to pre-IS levels within 2–3 days. The impact of IS on microorganisms in coolers was varied, with reductions of 2–4 Log10, and required 2 to 4 weeks to return to pre-IS levels. The results near fabrication lines were mixed, with little to no significant changes at one plant, while at the other, two processing lines showed 4 to 6 Log10 reductions. Resistance to QAC and the protection of Salmonella by the biofilms varied between plants and between areas of the plants as well. Community profiling of bacteria at the genus level showed that IS reduced species diversity and the disruption led to new community compositions that in some cases did not return to the pre-IS state even after 15 to 16 weeks. Discussion: The results found here reveal the impact of using IS to disrupt the presence of pathogen or spoilage microorganisms in US pork processing facilities may not have the intended effect.