Category Archives: Microbiological Risk Assessment

Research – Efficacy of Selected Powdered Floor Treatments Against Salmonella, E. coli, and L. monocytogenes on Polyurethane-Concrete Flooring Material Carriers

Journal of Food Protection

Food processing environment flooring can become contaminated with pathogens in many ways including foot and equipment traffic, incoming materials, and floor drain backups.  Natural antimicrobial turmeric and commercially available powdered floor treatments may reduce the levels of pathogens on flooring thereby reducing the risk of cross contamination from the floor to food contact surfaces. These chemicals were evaluated to determine their effectiveness against cocktails of Salmonella , Escherichia coli , and Listeria monocytogenes dried onto the surfaces of carriers made from polyurethane-concrete commercial flooring material.  Aqueous test solutions were prepared from the minimum treatment required per m 2 from the manufacturer’s instructions diluted in sterile water.  Potential synergy between turmeric and a percarbonate based commercial floor treatment was explored with a mixture of turmeric and sodium percarbonate, each at approximately 37g/m 2 application rate.  Each inoculated carrier was exposed to the treatment solutions or a sterile water control for 10 minutes at room temperature, neutralized with Hi-Cap neutralizing broth, the bacteria suspended, enumerated, and log 10 reductions calculated for each treatment and inoculum combination.  Mean log 10 CFU/carrier reductions with standard deviations ranged between 4.29±0.34 for the sodium percarbonate (SPC) based treatment and 0.004±0.23 for turmeric for Salmonella , 4.81±0.16 for SPC based treatment and -0.16±0.62 for turmeric for E. coli , and 4.88±0.6 for SPC based treatment and -0.16±0.15 for turmeric for L. monocytogenes .

Research – Strategies for Biocontrol of Listeria monocytogenes Using Lactic Acid Bacteria and Their Metabolites in Ready-To-Eat Meat- and Dairy-Ripened Products

MDPI

Listeria monocytogenes is one of the most important foodborne pathogens. This microorganism is a serious concern in the ready-to-eat (RTE) meat and dairy-ripened products industries. The use of lactic acid bacteria (LAB)-producing anti-L. monocytogenes peptides (bacteriocins) and/or lactic acid and/or other antimicrobial system could be a promising tool to control this pathogen in RTE meat and dairy products. This review provides an up to date about the strategies of use of LAB and their metabolites in RTE meat products and dairy foods by selecting the most appropriate strains, by analysing the mechanism by which they inhibit L. monocytogenes and methods of effective application of LAB, and their metabolites in these kinds of products to control this pathogen throughout the processing and storage. The selection of LAB with anti-L. monocytogenes activity allows to dispose of effective strains in meat and dairy-ripened products, achieving reductions form 2–5 logarithmic cycles of this pathogen throughout the ripening process. The combination of selected LAB strains with antimicrobial compounds, such as acid/sodium lactate and other strategies, as the active packaging could be the next future innovation for eliminating risk of L. monocytogenes in meat and dairy-ripened products.

Research – Aflatoxin B1 in rice: effects of storage duration, grain type and size, production site and season

Journal of Food Protection

Our study aimed to evaluate the AFB1 levels in packed rice marketed in Lebanon and determine the exposure to this toxin from the rice consumption. A total of 105 packed white, parboiled and brown rice bags were collected. ELISA was used to measure AFB1. A comprehensive FFQ was filled by 500 participants to determine the patterns of rice consumption and subsequently the exposure levels to AFB1 from the rice consumption in Lebanon. AFB1 was detected in all rice samples (100%). The average concentration ± standard deviation of AFB1 was 0.5±0.3μg/kg. Contamination ranged between 0.06 and 2.08μg/kg. Moisture content in all rice samples was below the recommended percentage (14%). Only 1% of the samples had an AFB1 level above the European Union (EU) limit (2μg/kg). Brown rice had a significantly higher AFB1 level than white and parboiled rice (p=0.02), while a significant difference was found between both collections for the same brands (p=0.016). Packing season, packing country, country of origin, presence of a food safety management certification, grain size, and time between packing and purchasing had no significant effect. Exposure to AFB1 from rice consumption in Lebanon was calculated as 0.1-2 ng/kg bodyweight/day.

USA – FDA Enforcement Report – MaryRuth’s Organic Infants Liquid Probiotic; Unflavored, a Dietary Supplement – Pseudomonas aeruginosa.

FDA

Product Description:  Updated

MaryRuth’s Organic Infants Liquid Probiotic; Unflavored, a Dietary Supplement.1 fl. oz. (30 mL)UPC: 8 56645 00858 7Serving size (five drops – start with one and work up to 5)Organic Proprietary Probiotic Blend 250 mg. Bifidobacterium lactis Bifidobacterium infantis Bifidobacterium bifidum Lactobacillus reuteri Other ingredients: A blend of probiotics in an enzyme enriched substrate, extracted with water from a proprietary blend of three organic grasses.

Reason for Recall: Internal testing found the presence of Pseudomonas aeruginosa in the product.

Product Quantity: Lot# 100420218 = 23,223 Lot# 100520218 = 2,450

Recall Number: F-0214-2022

Code Information: lots: 100420218, expiry 4/2023 and 100520218, expiry 5/2023

Classification: Class I

Event ID: 88956

Voluntary / Mandated:

Voluntary: Firm initiated

Product Type: Food

Recalling Firm:

MARY RUTH ORGANICS
1171 S Robertson Blvd #
Los Angeles, CA 90035-1403
United States

Recall Initiation Date: 10/28/2021

Center Classification Date: 11/19/2021

Date Terminated:2/18/2022

USA – Las Vegas – Health district: More than 30 report illness after eating at restaurant

Review Journal

More than 30 people have reported becoming ill after they consumed food and/or drink at a northwest Las Vegas restaurant, according to the Southern Nevada Health District.

Secret of Siam, 5705 Centennial Center, has been closed as the health district investigates.

“The Health District has received reports from more than 30 people whose symptoms included increased heart rate, blurry vision, hallucinations, disorientation or confusion, dizziness or vertigo, loss of consciousness, dry mouth, and numbness and tingling in extremities within hours of consuming food or drink from Secret of Siam,” a health district news release stated.

The incidents occurred in January and February.

Anyone who may have eaten food at the restaurant is asked to take a survey at www.snhd.info/siamsurvey.

UK – Dogs Choice UK recalls frozen raw dog foods because of the presence of Salmonella

FSA

Dogs Choice UK is recalling a number of frozen raw dog foods because Salmonella has been found in the products.

Product details

Frozen Chicken and Beef
Pack size 500g
Batch code 080222+2
Best before 08 August 2022
Frozen Chicken and Beef Ready Meal
Pack size 500g
Batch code 080222+2
Best before 08 August 2022
Frozen Chicken Liver
Pack size 500g
Batch code 080222+2
Best before 08 August 2022

Risk statement

The presence of Salmonella in the products listed above. Salmonella is a bacterium that can cause illness in humans and animals. The product could therefore carry a potential risk, because of the presence of Salmonella, either through direct handling of the pet food, or indirectly, for example from pet feeding bowls, utensils or contact with the faeces of animals. In humans, symptoms caused by Salmonella usually include fever, diarrhoea and abdominal cramps. Infected animals may not necessarily display signs of illness, but symptoms can include diarrhoea.

Action taken by the company

Dogs Choice UK is recalling the above products. Point of sale notices will be displayed in the retail stores that sold these products. The notices explain to customers why the products are being recalled and tell them what to do if they have bought the product.

Our advice to consumers

Research – Antibacterial Properties of TMA against Escherichia coli and Effect of Temperature and Storage Duration on TMA Content, Lysozyme Activity and Content in Eggs

MDPI

Studies on trimethylamine (TMA) in egg yolk have focused on how it impacts the flavor of eggs, but there has been little focus on its other functions. We designed an in vitro antibacterial test of TMA according to TMA concentrations that covered the TMA contents typically found in egg yolk. The change in TMA content in yolk was analyzed at different storage temperatures and for different storage durations. The known antibacterial components of eggs, including the cuticle quality of the eggshell and the lysozyme activity and content in egg white, were also assessed. The total bacterial count (TBC) of different parts of eggs were detected. The results showed that the inhibitory effect of TMA on Escherichia coli (E. coli) growth increased with increasing TMA concentration, and the yolk TMA content significantly increased with storage duration (< 0.05). The cuticle quality and lysozyme content and activity significantly decreased with storage time and increasing temperature, accompanied by a significant increase in the TBC on the eggshell surface and in the egg white (< 0.05). This work reveals a new role for trace TMA in yolks because it reduces the risk of bacterial colonization, especially when the antibacterial function of eggs is gradually weakened during storage.

Research – Scientists identify environmental cue linked to illness caused by Salmonella

Science Daily

To survive in hostile environments, bacteria attach to one another, forming a supportive framework known as a biofilm. In biofilms of Salmonella — a major cause of food-borne diarrheal illness — a key component of this framework is curli amyloid protein.

Now, in new research, scientists at the Lewis Katz School of Medicine at Temple University show that the repression of curli by an environmental factor in the intestine plays a critical role in freeing Salmonella bacteria of strain S. Typhimurium from their biofilms, enabling them to cause active infection. The environmental cue is nitrate, which both represses curli and modulates levels of an intracellular molecule known as cyclic-di-GMP. These events ultimately lead to the activation of S. Typhimurium flagella, which in humans is a critical step in allowing individual S. Typhimurium bacteria to swim toward and infect intestinal cells.

“It had been unclear what factors trigger S. Typhimurium to switch between a sessile, biofilm lifestyle to a motile, free-swimming lifestyle in the intestine,” explained Çagla Tükel, PhD, Director of the Center for Microbiology and Immunology at the Katz School of Medicine and senior investigator on the new study. “Our study shows for the first time that nitrate produced in the intestinal lumen of the host serves as an environmental cue driving this switch.”

Research – Prevalence of Mycobacterium bovis in milk on dairy cattle farms: An international systematic literature review and meta-analysis

Science Direct

Bovine tuberculosis, caused by Mycobacterium bovis (M. bovis), is a globally distributed chronic disease of animals. The bacteria can be transmitted to humans via the consumption of unpasteurised (raw) milk, thus representing an important public health risk. To investigate the risk of zoonotic transmission of M. bovis via raw milk, this study systematically reviewed published studies to estimate the prevalence of M. bovis in on-farm bulk-tank milk (BTM) and individual cow’s milk (IM) by meta-analysis.

In total, 1,339 articles were identified through seven electronic databases and initially screened using titles and abstracts. The quality of 108 potentially relevant articles was assessed using full texts, and 67 articles comprising 83 studies (76 IM and 7 BTM), were included in the meta-analysis. The prevalence of M. bovis in IM and BTM was summarised according to the diagnostic test used, and the tuberculin skin test (TST) infection status of the individual cows (for IM) or herds (for BTM). Heterogeneity was quantified using the I-squared statistic. Prediction intervals (95% PIs) were also estimated.

For IM, the overall prevalence was summarised at 5% (95%CI: 3%–7%). In TST positive cows, prevalence was summarised at 8% (95%CI: 4%–13%). For BTM, the overall prevalence independent of individual herd TST infection status was summarised at 5% (95%CI: 0%–21%).

There was considerable heterogeneity evident among the included studies, while PIs were also wide. Inconsistency in the quality of reporting was also observed resulting in missing information, such as the TST infection status of the individual animal/herd. No study reported the number of M. bovis bacteria in test-positive milk samples. Several studies reported the detection of M. tuberculosis and M. africanum in milk.

Despite international efforts to control tuberculosis, this study highlights the risk of zoonotic transmission of M. bovis via unpasteurised milk and dairy products made using raw milk.

Research – Microbial safety and sanitary quality of strawberry primary production in Belgium: risk factors for Salmonella and Shiga toxin producing Escherichia coli (STEC) contamination.

AEM

Hepatitis A kswfoodworld

Strawberries are an important fruit in Belgium both in production and consumption, but little information is available about the presence of Salmonella and STEC in these berries, the risk factors in agricultural production and possible specific mitigation options. In 2012, a survey was undertaken of three soil and three soilless cultivation systems in Belgium. No Salmonella spp. was isolated. No STEC was detected in the strawberry samples (0 out of 72), but STEC was detected by qPCR in 11 out of 78 irrigation water and 2 out of 24 substrate samples.

Culture isolates were obtained for 2 out of 11 qPCR positive irrigation water samples and 2 out of 2 substrate samples. Multivariable logistic regression analysis revealed elevated generic E. coli numbers (odds ratio (OR) for 1 log increase being 4.6) as the most important risk factor for STEC, together with the berry picking season (elevated risk in summer).

Presence of generic E. coli in the irrigation water (≥ 1 cfu per 100 ml) was mainly influenced by the type of irrigation water (collected rainfall water stored in ponds was more often contaminated than ground water pumped from boreholes (OR = 5.8)) and the lack of prior treatment (untreated water versus water subjected to sand filtration prior to use (OR = 19.2)).

The follow-up study in 2013 at one of the producers indicated cattle as the most likely source of STEC contamination of the irrigation water.