Cross-contamination risks in dry produce packinghouses: Efficacy of alcohol-based sanitizers to reduce Salmonella and potential surrogates on relevant surface materials.

A 2020 Salmonella outbreak was epidemiologically linked to red onions; however, insufficient cleaning and sanitation in the packinghouse expanded the recall to include all onions handled by the packing house in the preceding 3 months. Our objective was to evaluate the efficacy of dry sanitizers to reduce cross-contamination risk on food contact surfaces (FCS) found in post-harvest packing areas. Transfer of Salmonella and potential surrogates (Escherichia coli, Enterococcus faecium) to and from onions to FCS materials (high density polypropylene, polyester-nylon conveyor belts, plywood) was quantified.

Variability in cadmium tolerance of closely related isolates originating from dairy processing environments.

Unlabelled: Increased tolerance to cadmium in has been suggested to contribute to their persistence in natural and food production environments. This study investigated the phenotypic cadmium response of strains with efflux pump (variants 1-4) and related strains with . Growth of variant strains ( = 5) in 0 µM-120 µM cadmium salts (CdCl, CdSO) in Mueller-Hinton broth (MHB) was evaluated.

Escherichia coli Survival on Dry Bulb Onions Treated with Crop Protection Sprays Prepared using Contaminated Water in the Treasure Valley Growing Region.

Contaminated agricultural water has been implicated in produce-associated outbreaks, including dry bulb onions (Allium cepa). This study was designed to quantify risks associated with contaminated water used to prepare crop protection sprays applied immediately before the onset of field curing of dry bulb onions. Laboratory experiments determining the behavior of Salmonella and Escherichia coli in crop protection chemical solutions were performed to guide selection for field use.

Resolved genomes of wastewater ESBL-producing and metagenomic analysis of source wastewater samples.

Extended-spectrum beta-lactamase (ESBL)-producing pose a serious threat to human health because of their resistance to the most commonly prescribed antibiotics: penicillins and cephalosporins. In this study, we provide a genomic and metagenomic context for the determinant beta-lactam resistance genes of ESBL-positive isolated from various wastewater treatment utilities in Oregon, USA. Class A beta-lactamase genes on chromosomes (CTX-M, TEM) were clustered with antibiotic resistance genes associated with other classes of antibiotics (sulfonamides and aminoglycosides) along with insertional elements.

Irrigation Method Matters: Contamination and Die-off Rates of Escherichia coli on Dry Bulb Onions After Overhead and Drip Irrigation in Washington State (2022-2023).

Two U.S. outbreaks of salmonellosis in 2020 and 2021 were epidemiologically linked to red onions.

Optimized Ultraviolet-C Processing Inactivates Pathogenic and Spoilage-Associated Bacteria while Preserving Bioactive Proteins, Vitamins, and Lipids in Human Milk.

Holder pasteurization (HoP) enhances donor human milk microbiological safety but damages many bioactive milk proteins. Though ultraviolet-C irradiation (UV-C) can enhance safety while better preserving some milk proteins, it has not been optimized for dose or effect on a larger array of bioactive proteins. We determined the minimal UV-C parameters that provide >5-log reductions of relevant bacteria in human milk and how these treatments affect an array of bioactive proteins, vitamin E, and lipid oxidation.

Characterizing Spoilage of Coconut-based Creamers: A Multifaceted Approach to Identify Problematic Bacteria and Their Potential Sources in a New Product Category.

Beverage innovation is a growing trend with a reliance on comanufacturing relationships to launch products quickly. A recent comanufacturing relationship is the utilization of dairy processing facilities to process plant-based beverages using high-temperature short-time (HTST) pasteurization. While the shelflife of HTST bovine milk is well established at 21 days, retailers are expecting new refrigerated beverages to achieve a 60-day shelflife.

Efficacy of cleaning and sanitizing procedures to reduce Listeria monocytogenes on food contact surfaces commonly found in fresh produce operations.

Cleaning and/or sanitizing methods were evaluated to reduce Listeria monocytogenes (Lm) on coupons of porous (PS; polyester-nylon with coating conveyor belt [PNCB], plywood [PW]) and non-porous (NPS; high density polyethylene, stainless steel) surfaces. Coupons (2.5 cm diameter) were inoculated with six-strain cocktail with cabbage juice, inverted and incubated on tryptic soy agar with yeast extract (TSAYE; 37 °C, 24 h).

Before and After: Evaluation of Microbial and Organic Loads in Produce Handling and Packing Operations with Diverse Cleaning and Sanitizing Procedures.

Inadequate cleaning and/or sanitation (C/S) of food contact surfaces (FCSs) has been frequently reported during Produce Safety Rule inspections; however, limited data are available evaluating the effectiveness of C/S processes in produce operations. Different C/S practices were evaluated in four fresh produce operations for their efficacy in reducing microbial and organic loads on various FCSs. Microbial (aerobic plate counts; APC) and organic (ATP) loads were quantified during production, after cleaning, and after sanitizing, if applicable.

High-Pressure Processing of Human Milk: A Balance between Microbial Inactivation and Bioactive Protein Preservation.

Background: Donor human milk banks use Holder pasteurization (HoP; 62.5°C, 30 min) to reduce pathogens in donor human milk, but this process damages some bioactive milk proteins.

Objectives: We aimed to determine minimal parameters for high-pressure processing (HPP) to achieve >5-log reductions of relevant bacteria in human milk and how these parameters affect an array of bioactive proteins.

Evaluating for its potential to reduce shelf life in reworked high-temperature, short-time fluid milk products.

Rework is a common practice used in the dairy industry as a strategy to help minimize waste from processing steps or errors that might otherwise render the product unsaleable. Dairy processors may rework their high-temperature, short-time (HTST) fluid milk products up to code date (21 d) at a typical dilution rate of ≤20% rework into ≥80% fresh raw milk. Bacterial spores present in raw milk that can survive pasteurization and grow at refrigeration temperatures are often responsible for milk spoilage.

Resistome characterization of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolated from wastewater treatment utilities in Oregon.

Infections resistant to broad spectrum antibiotics due to the emergence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae is of global concern. This study characterizes the resistome (i.e.

Water Application Method Influences Survival or Growth of Escherichia coli on Bulb Onions during Field Curing.

Abstract: The impact of water application method on bacterial survival at or after the final irrigation was evaluated in bulb onions during commercially relevant field drying (curing). A three-strain rifampin-resistant cocktail of Escherichia coli was introduced to onions via a single overhead spray application in two separate trials (5.22 [trial 1] or 2.

Probing antimicrobial resistance and sanitizer tolerance themes and their implications for the food industry through the Listeria monocytogenes lens.

The development of antibiotic resistance is a serious public health crisis, reducing our ability to effectively combat infectious bacterial diseases. The parallel study of reduced susceptibility to sanitizers is growing, particularly for environmental foodborne pathogens, such as Listeria monocytogenes. As regulations demand a seek-and-destroy approach for L.

Adaptation to a Commercial Quaternary Ammonium Compound Sanitizer Leads to Cross-Resistance to Select Antibiotics in Isolated From Fresh Produce Environments.

The effective elimination of through cleaning and sanitation is of great importance to the food processing industry. Specifically in fresh produce operations, the lack of a kill step requires effective cleaning and sanitation to mitigate the risk of cross-contamination from the environment. As facilities rely on sanitizers to control , reports of the development of tolerance to sanitizers and other antimicrobials through cross-resistance is of particular concern.

Nonstarter Bacterial Communities in Aged Cheddar Cheese: Patterns on Two Timescales.

The aim of this study was to investigate the temporal stability of microbial contamination during cheddar cheese production by examining patterns of nonstarter bacteria in 60-day aged cheddar collected from the start and end of 30 consecutive production days. Further, we explored the source of these temporal microbial variations by comparing microbial communities in the aged cheese to those on food contact surfaces from a piece of cheesemaking equipment previously identified as a major source of nonstarter bacteria in the same processing environment. 16S rRNA metabarcoding and culture-based sequencing methods identified two Streptococcus sequence variants significantly associated with the end of the production day in both the aged cheese and the cheese processing environment.

Application of Whole Genome Sequencing to Understand Diversity and Presence of Genes Associated with Sanitizer Tolerance in from Produce Handling Sources.

Recent listeriosis outbreaks linked to fresh produce suggest the need to better understand and mitigate contamination in packing and processing environments. Using whole genome sequencing (WGS) and phenotype screening assays for sanitizer tolerance, we characterized 48   isolates previously recovered from environmental samples in five produce handling facilities. Within the studied population there were 10 sequence types (STs) and 16 cgMLST types (CTs).

Impact of biosolids amendment and wastewater effluent irrigation on enteric antibiotic-resistant bacteria - a greenhouse study.

Reuse of wastewater effluent and biosolids in agriculture is essential to sustainable water and nutrient resource management practices. Wastewater and biosolids, however, are reportedly the recipients, reservoirs, and sources of antibiotic-resistant enteric pathogens. While decay rates of fecal bacterial indicators in soil are frequently studied, very few studies have reported on the persistence of the antibiotic-resistant sub-populations.

Population dynamics of coliforms in a commercial Cheddar cheese production facility.

The detection of coliforms in young cheese is a potential indication of undesirable microbial growth within the processing environment. The aim of this study was to investigate sources and conditions that lead to the intermittent detection of coliforms (1-3 log cfu/g) in young Cheddar cheese at a single commercial facility. Analysis of historical production data, in combination with iterative investigative sampling events, was performed to determine coliform levels in milk, whey, curd, and surfaces at the beginning, middle, and end of the production day.

The Cheese Production Facility Microbiome Exhibits Temporal and Spatial Variability.

A primary goal of modern cheese manufacturing is consistent product quality. One aspect of product quality that remains poorly understood is the variability of microbial subpopulations due to temporal or facility changes within cheese production environments. Therefore, our aim was to quantify this variability by measuring day-day and facility-facility changes in the cheese facility microbiome.

Growth potential and biofilm development of nonstarter bacteria on surfaces exposed to a continuous whey stream.

Commercial Cheddar cheese production uses an automated, continuous production system that provides favorable conditions for specific undesirable bacterial subpopulations in certain sections of the processing system. The draining and matting conveyor (DMC) is a large, fully enclosed series of conveyor belts that separates curd and whey on the first drain belt and supports the cheddaring process in subsequent sections. In a previous study, we demonstrated that coliforms increase in the draining section of the DMC (pH 6.

Relative performance of commercial citric acid and quaternary ammonium sanitizers against Listeria monocytogenes under conditions relevant to food industry.

Growth of Listeria monocytogenes in cold temperatures coupled with its tolerance of antimicrobials can promote its survival and persistence in food processing environments. The food industry relies heavily on cleaning and sanitation to control L. monocytogenes; therefore, it is important to understand the environmental context (i.

Bile Salt-Stimulated Lipase Activity in Donor Breast Milk Influenced by Pasteurization Techniques.

Breast milk contains bile salt-stimulated lipase (BSSL), which significantly increases the fat digestion capacity of newborns who have limited pancreatic lipase secretion in the first few months after birth. Problematically, Holder pasteurization used in non-profit milk banks to ensure the microbiological safety of donor milk for infants, particularly preterm infants (<37 weeks gestation age), destroys milk BSSL, thus limiting infant fat absorption capacity. Alternative strategies are needed to ensure the safety of donor milk while preserving BSSL activity.

Prevalence of Listeria spp. in produce handling and processing facilities in the Pacific Northwest.

Listeria monocytogenes is a significant concern for the produce industry; however, there is limited information to support the practical decision-making to mitigate this risk. This study investigated the prevalence of Listeria spp. and L.