Research Publications (Food Safety)

L. monocytogenes was associated with more than 60 produce recalls between 2017 and 2020 including tomato, cherry, broccoli, lemon, and lime recalls. This study describes the effects of temperature, time and food substrate as factors influencing L. monocytogenes behavior on whole intact raw fruits and vegetables. A cocktail of five L. monocytogenes strains previously associated with foodborne outbreaks were used.

Various methods exist for the enrichment and detection of Listeria spp. and L. monocytogenes from environmental samples. Procedures for the compositing of environmental samples are not as well-defined. In this study, different enrichment procedures involving Buffered Listeria Enrichment Broth (BLEB), University of Vermont Medium (UVM), and Fraser Broth (FB) were evaluated to determine the limits of detection (LOD) for L.

Research suggests that small and independent delis are less likely to follow proper sanitation procedures, including slicer inspection, which could lead to a higher likelihood of these delis being a reservoir for Listeria monocytogenes growth and cross-contamination.    This study was undertaken to determine the incidence of L. monocytogenes in counter-sliced turkey deli meat obtained from independent delis in an urban city.

Following two O121 STEC outbreaks linked to wheat flour, this study was conducted to gain baseline information on the occurrence of bacterial pathogens and levels of indicator organisms in wheat flour in Canada. A total of 347 pre-packaged wheat flour samples were analyzed for Salmonella spp., Shiga Toxin-Producing Escherichia coli (STEC), Listeria monocytogenes ( L. monocytogenes ) , aerobic colony count (ACC), total coliforms, and generic Escherichia coli ( E. coli ) .

ABSTRACT While high temperature heat treatments can efficiently reduce pathogen levels, they also affect the quality and nutritional profile of foods, as well as increase the cost of processing. The food additive butyl para-hydroxybenzoate (BPB) was investigated for its potential to synergistically enhance the thermal inactivation at mild heating temperatures (54 – 58 ºC).

Persistent contamination of food manufacturing environments by Listeria monocytogenes is an important public health risk because such contamination events defy standard sanitization protocols, for example, the application of quaternary ammonium compounds such as benzalkonium chloride (BC), providing a source for prolonged dissemination of the bacteria in food products. We performed whole-genome sequence (WGS) analyses of 1279 well-characterized L.

Growing consumer desires for clean label, “natural” products drives more meat processors to cure meat products with natural sources of nitrate or nitrite such as celery juice powder (CJP). One particular challenge for these producers is to identify safe cooling rates in CJP-cured products where extended cooling could allow growth of pathogens. USDA FSIS recently added guidelines for stabilization of meat products cured using naturally occurring nitrites, based on control of Clostridium spp .

Grocery stores handle fresh produce in large quantities daily. According to the Food and Drug Administration Food Code, food is to be stored at least 15 cm above the floor, and all foods shall be protected from any source of contamination or otherwise discarded. It is reported in the literature that dropped produce could be a potential source of microbial contamination.

Listeria monocytogenes (Lm) is one of the leading causes of death due to foodborne illness, affecting the elderly, pregnant women, neonates and the immune compromised. Serologically, Lm can be classified into 13 serotypes, though only four are typically linked with food contamination and illness. Since 2000, a shift in serotypes involved in listeriosis outbreaks was observed, suggesting that tracking of serotypes could help identify emerging trends.

Bacterial foodborne diseases are one of the most important public health issues worldwide but in Ecuador reports on the microbiological quality of foods are scarce. In this cross-sectional study, a total of 450 samples of high-demand Ecuadorian food, including bolon, encebollado, sauces, ceviche, fruits, fruit juices, fruit salads, cheese, raw chicken and ground beef were collected from popular street markets in the cities of Guayaquil, Quito and Cuenca.

A comprehensive understanding of foodborne pathogen diversity in pre-harvest environments is necessary to effectively track pathogens on farms and identify sources of produce contamination. As such, this study aimed to characterize Listeria diversity in wildlife feces and agricultural water collected from a New York State produce farm over a growing season. Water samples were collected from a pond (N=80) and stream (N=52).

The ability of the enterocin-A-B-P-producing Enterococcus faecium KE82 adjunct strain to inactivate Listeria monocytogenes during Galotyri PDO cheese processing was evaluated. Three artisan cheese trials from traditionally ‘boiled’ (85oC) ewe’s milk were processed. The milk cooled at 42oC was divided in two parts: A1 was inoculated with Streptococcus thermophilus ST1 and Lactococcus lactis subsp. cremoris M78, and A2 with the basic starter ST1+M78 plus the KE82 adjunct (step 1).

The survival and virulence of Listeria monocytogenes was assessed during storage on three low-moisture foods (LMFs), chocolate liquor, corn flakes and shelled, dry-roasted pistachios (a w 0.18, 0.27, 0.20). The LMFs were inoculated with a 4-strain cocktail of L. monocytogenes at 8 log CFU/g, dried, equilibrated and then stored at 4°C, 25–81% relative humidity (RH) and 23°C, 30–35% RH for at least 336 days. At 4°C, L. monocytogenes remained stable on the LMFs for at least 336 days.

The practice of soaking almonds prior to consumption is popular both commercially and at home. The food safety implications of soaking almonds was investigated through analysis of blogs and videos (n = 85 recipes) to identify both the reasons for soaking almonds and the common practices employed. Among the recipes analyzed, the most common reasons for soaking almonds (94.1%) were perceived benefits such as improved digestion and nutrient uptake.

In England and Wales, Public Health England (PHE) applies whole genome sequencing (WGS) to cultures of Listeria monocytogenes recovered from human cases of listeriosis, foods and food production environments. Following the routine inspection of a small retailer in February and March 2016, two unopened packs of cooked chicken produced by the same manufacturer were contaminated with L. monocytogenes at levels of 340 and 20 CFU/g. A public recall of this product was issued in March 2016.

Biofilms have a significant impact on food safety in the food industry. Many foodborne outbreaks have been associated with pathogenic strains that can form a biofilm. The present study aimed to examine the ability to form biofilms by pathogenic strains collected from retail food samples under the Official Control and Monitoring Program in Poland.

Results from monitoring of the microbiological quality of 2,721 samples of ready-to-eat cooked chicken collected between 2013 to 2017 in England were reviewed: 70% of samples were from retail, catering or manufacture and 30% were imported and collected at English ports. Samples were tested for a range of bacterial pathogens and indicator organisms. Six samples (<1%) had unsatisfactory levels of pathogens which were potentially injurious to health.

The goal of this research was to evaluate the efficacy of a novel rechargeable non-leaching polycationic N-halamine coating applied to stainless steel (STEEL) food contact surfaces to reduce Listeria monocytogenes contamination on ready-to-eat (RTE) foods. For this purpose, four L. monocytogenes strains were inoculated onto the charged (C; chlorine-activated) or uncharged (NC) N-halamine coated STEEL coupon surfaces (intact vs. scratched).

Past studies have shown that the on-farm distribution of Listeria monocytogenes is affected by environmental factors (e.g., weather). However, the majority of studies were conducted at large scales (e.g., across farms), while few studies examined drivers of L. monocytogenes prevalence at smaller scales (e.g., within a single field). This study was performed to address this knowledge gap by (i) tracking L.

We aimed to perform serotyping and the antimicrobial resistance profile of Salmonella spp. and Listeria monocytogenes strains isolated from raw meats imported illegally into Brazil along the borders of Argentina and Uruguay. Distinct isolates of Salmonella spp. (n=6) and L. monocytogenes (n=25) obtained from 270 of these food products of earlier work were serotyped and tested for antimicrobial resistance by agar disc diffusion method.

In relation to milk hygiene and safety, the milking phase is considered a critical moment since it represents a probable pathway for the introduction of unwanted microorganisms in the dairy chain. In particular, Listeria monocytogenes (L. monocytogenes) and Escherichia coli ( E. coli ) are known as possible microbial contaminants of raw sheep milk although extensive knowledge regarding their contamination dynamics in sheep farms is still lacking.

Listeria monocytogenes (L. mono) is commonly found in retail deli environments. Proper types and concentrations of sanitizers must be used to eliminate this pathogen from surfaces and reduce the consumer’s risk for infection. In 2012, the CDC’s Environmental Health Specialists Network completed a study on practices in retail delis that can help prevent cross-contamination and growth of L. mono.

Listeria monocytogenes (LM) contamination of produce can often be traced back to the environment of packinghouses and fresh-cut facilities. As there is limited information on the detection, prevalence, and distribution of this pathogen in produce operations, environmental “routine sampling” plans for LM and other Listeria spp. were developed and implemented in three packinghouses and five fresh-cut facilities in the US.

More efficient sampling and detection methods of pathogens on fresh produce are needed. The purpose of this study was to compare a novel rinse/membrane filtration method (RMFM) to a more traditional sponge rubbing or stomaching method in processing jalapeño peppers and cantaloupe samples for detection of Escherichia coli , Salmonella enterica , and Listeria monocytogenes .

Ready-to-eat (RTE) meat and poultry product samples collected between 2005 and 2017 from RTE producing establishments for the Food Safety and Inspection Service’s (FSIS’s) ALLRTE/RTEPROD_RAND (random) and RTE001/RTEPROD_RISK (risk-based) sampling projects were tested for Listeria monocytogenes ( Lm ).