Category Archives: microbial contamination

Research – Fate of Listeria monocytogenes, Salmonella spp., and Shiga Toxin-Producing Escherichia coli on Slices of an All-Beef Soppressata during Storage

Posted on May 15, 2023 by | Leave a comment

MDPI

Abstract

Cells of Listeria monocytogenes, Salmonella spp., or Shiga toxin-producing Escherichia coli (STEC) were inoculated (ca. 4.0 log CFU/slice) onto slices (ca. 4 g each slice) of an all-beef soppressata (ca. pH 5.05 and aw 0.85). The storage of vacuum-sealed slices of inoculated soppressata at 4 °C or 20 °C for 90 days resulted in reductions of all three pathogens by ca. 2.2 to 3.1 or ca. ≥3.3 log CFU/slice, respectively. When pathogen levels decreased to below detection (≤1.18 log CFU/slice) by direct plating, it was possible to recover each of the target pathogens by enrichment, albeit more frequently from slices stored at 4 °C (p < 0.05) compared to 20 °C. In summary, the slices of the commercially produced beef soppressata selected for this study did not provide a favorable environment for either survival or outgrowth of surface-inoculated cells of L. monocytogenes, Salmonella spp., or STEC during storage.

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Listeria, Listeria monocytogenes, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Salmonella, STEC, STEC E.coli

New Research Links Foodborne E. Coli Infections to “Hundreds of Thousands” of UTIs in U.S.

Posted on May 15, 2023 by | Leave a comment

Food Safety Magazine

A new study suggests that Escherichia coli infection from contaminated meat products may be responsible for hundreds of thousands of urinary tract infections in the U.S. each year.

A team of scientists led by George Washington University (GWU) Milken Institute School of Public Health researchers have developed a new genomic approach for tracking the origins of E. coli infections. Using this method, the team estimated that between 480,000 and 640,000 UTIs in the United States each year may be caused by foodborne E. coli strains.

According to GWU, E. coli is the most common cause of UTIs, causing upwards of 85 percent of cases each year. Women are at greater risk of developing UTIs, which can range from simple bladder infections to life-threatening bloodstream infections. At present, only specific types of diarrhea-causing E. coli, such as E. coli O157:H7, are rigorously monitored by the U.S. Food and Drug Administration (FDA), but the new findings from GWU suggest that other strains may also pose serious health risks.

In the study, researchers collected raw chicken, turkey, and pork from major grocery store chains in Flagstaff, Arizona, and isolated E. coli from the meat samples. Simultaneously, researchers collected urine and blood E. coli isolates from patients hospitalized at the Flagstaff Medical Center for UTIs.

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Posted in bacterial contamination, Contaminated water, Decontamination Microbial, E.coli, escherichia coli, food contamination, Food Micro Blog, Food Microbiology, Food Microbiology Blog, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk

Research – Salmonella Biofilm Formation under Fluidic Shear Stress on Different Surface Materials

Posted on May 15, 2023 by | Leave a comment

MDPI

Abstract

This study characterized biofilm formation of various Salmonella strains on common processing plant surface materials (stainless steel, concrete, rubber, polyethylene) under static and fluidic shear stress conditions. Surface-coupons were immersed in well-plates containing 1 mL of Salmonella (6 log CFU/mL) and incubated aerobically for 48 h at 37 °C in static or shear stress conditions. Biofilm density was determined using crystal violet assay, and biofilm cells were enumerated by plating on tryptic soy agar plates. Biofilms were visualized using scanning electron microscopy. Data were analyzed by SAS 9.4 at a significance level of 0.05. A surface–incubation condition interaction was observed for biofilm density (p < 0.001). On stainless steel, the OD600 was higher under shear stress than static incubation; whereas, on polyethylene, the OD600 was higher under static condition. Enumeration revealed surface–incubation condition (p = 0.024) and surface–strain (p < 0.001) interactions. Among all surface–incubation condition combinations, the biofilm cells were highest on polyethylene under fluidic shear stress (6.4 log/coupon; p < 0.001). Biofilms of S. Kentucky on polyethylene had the highest number of cells (7.80 log/coupon) compared to all other strain–surface combinations (p < 0.001). Electron microscopy revealed morphological and extracellular matrix differences between surfaces. Results indicate that Salmonella biofilm formation is influenced by serotype, surface, and fluidic shear stress.

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Posted in Biofilm, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Salmonella

Research – Effects of Selected Essential Oils on Listeria monocytogenes in Biofilms and in a Model Food System

Posted on May 15, 2023 by | Leave a comment

MDPI

Abstract

The composition of 18 essential oils was determined using gas chromatography–mass spectrometry, and their antilisterial activity was evaluated by the disk diffusion method, followed by the determination of the minimum inhibitory and minimum bactericidal concentrations. The most active essential oils were oregano, thyme, cinnamon, winter savory, and clove, with MIC values ranging from 0.09 to 1.78 µL/mL. We investigated the biofilm-forming potential of Listeria monocytogenes on polystyrene at 5 °C, 15 °C, and 37 °C in three different media. The formation of biofilm was found to be dependent on the temperature and the availability of nutrients. After treatment with selected essential oils, the reduction in biofilm biomass was in the range of 32.61% and 78.62%. Micromorphological changes in the L. monocytogenes treated by oregano and thyme essential oils were observed in the form of impaired cell integrity and cell lyses by using scanning electron microscope. Oregano and thyme essential oils (MIC and 2MIC) significantly (p < 0.05) reduced the population of L. monocytogenes in minced pork meat during storage at 4 °C. In conclusion, the obtained results indicated the good activity of some selected essential oils on L. monocytogenes, with bacteriostatic, bactericidal, and antibiofilm effects at very low concentrations.

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Posted in Biofilm, essential oils, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Listeria, Listeria monocytogenes, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk

Research -Climate change and food safety: Temperature impact on the attachment of Escherichia coli pathogroups on cress leaf

Posted on May 14, 2023 by | Leave a comment

Wiley Online

Abstract

Climate change and its worldwide effects are undeniable. Temperature increase due to climate change may affect foodborne pathogen survival on fresh produce. This study aimed to present an evaluation of climate change impact regarding temperature rise situations, on attachment of different pathogenic Escherichia coli strains on cress grown under controlled conditions. EHEC O157:H7, EAEC O104:H4 and EPEC O26 were inoculated with initial inoculum concentration of 8 log MPN/mL at different stages during growth to observe how inoculation time (7, 14, 21 and 28 days post sowing; dps) and route (seed and leaves) affect pathogen load on fresh produce. This study revealed that temperature increase designed according to mitigation scenarios for climate change (+2, +4 and +6 °C) did not cause any considerable change in pathogen persistence on leaf at 30 dps (~4.5 to 7 log MPN/g). In plants contaminated at later stage (21 and 28 dps), higher bacterial populations were obtained for all temperatures studied. Our results show that E. coli translocated towards leaf portions from seed and established significant amount of pathogen load on leaf (~4 to 5.3 log MPN/g). Also, inoculated bacteria have tightly bound to leaf (~3.5 to 7 log MPN/g) and cannot be eliminated by washing. Although persistence of E. coli O157:H7, O104:H4 and O26 did not differ significantly according to temperature, the bacterial load on the leaves was above infectious dose for humans.

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Posted in Climate change, Decontamination Microbial, E.coli O104, E.coli O157, E.coli O157:H7, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, STEC, STEC E.coli

Research – Scientists Discover How Foodborne Vibrio Infects People, Could Lead to New Treatments

Posted on May 12, 2023 by | Leave a comment

Food Safety.Com

Food Illness

Researchers at the University of Texas (UT) Southwestern Medical Center have discovered how foodborne pathogen Vibrio parahaemolyticus infects people after eating raw or undercooked shellfish. The findings could lead to new ways to treat illness caused by the enteric bacteria.

The study provides the first visual evidence of how a gut bacterial pathogen uses an “assembly method” to build syringe-like structures to inject toxins into intestinal cells, giving a new view of how enteric bacteria, when exposed to bile acids, efficiently respond and build a virulence system.

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Posted in Antimicrobials, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Vibrio, Vibrio albensis, Vibrio alginolyticus, Vibrio cholera, vibrio cholerae, Vibrio parahaemolyticus, Vibrio vulnificans, Vibrio vulnificus

RASFF Alert- Animal Feed – Enterobacteriaceae – Poultry Meal

Posted on May 12, 2023 by | Leave a comment

RASFF

Exceeded parameter for Enterobacteriaceae in poultry meal from the UK in Netherlands and Belgium

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Posted in Animal Feed, Animal Feed Enterobacteriaceae, Animal Feed Testing, Enterobacteriaceae, Food Micro Blog, Food Microbiology Blog, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Pet Food Enterobacteriaceae, RASFF

RASFF Alerts- Animal Feed – Mold/Mould – Beet Pulp – Wheat Bran Pellets – Wheat

Posted on May 12, 2023 by | Leave a comment

RASFF

Mold in beet-pulp from Ukraine in Poland

RASFF

Wheat bran pellets for animal feed with molds and moisture from Angola in Portugal

RASFF

Wheat bran pellets for animal feed with molds and moisture from Angola in Portugal

RASFF

Wheat bran pellets for animal feed with molds and moisture from Angola in Portugal

RASFF

Mold in wheat from Ukraine in Poland and the Czech Republic

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Posted in Animal Feed, Animal Feed Mould Toxin, Animal Feed Testing, Food Micro Blog, Food Microbiology Blog, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, RASFF

Viet Nam – Seventy children hospitalized in Nghe An, food poisoning suspected

Posted on May 11, 2023 by | Leave a comment

Vietnamnet

More than 70 children aged from three to five from a preschool in the central province of Nghe An were rushed to hospitals after eating a snack on the evening of May 9.

Doctors at a general hospital in Do Luong District said the hospital admitted more than 70 children with symptoms of vomiting, stomach pain, diarrhea and dehydration.

They suspected that the children were food poisoned and that the yogurt was suspected as the cause of the incident, as many other two-year-old kids who did not eat the yogurt were well, the local media reported.

All of the children are rehydrated and in stable condition, and an investigation into the incident is underway.

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Posted in Food Illness, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, Food Poisoning, Foodborne Illness, Illness, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Poisoning

India – Two sisters die of suspected food poisoning in Rajasthan

Posted on May 11, 2023 by | Leave a comment

The Print

Jaipur, May 9 (PTI) Two girls died and their parents and a sister fell ill due to suspected food poisoning in Rajasthan’s Jhunjhunu district, police said on Monday.

The family members started vomiting after taking dinner on Monday night. When their condition deteriorated, locals took them to a hospital early Tuesday, Station House Officer of Gudha police station Veer Singh said.

Two girls Lakshya (8) and Tanishka (6) were declared brought at the hospital, he said, adding their father Buti Ram Meghwal (35), mother Anita (32) and sister Tanuja (11) are undergoing treatment.

The police officer said food samples have been collected for examination.

The postmortem of bodies has been conducted, he said. PTI SDA AQS AQS

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, Food Poisoning, Food Poisoning Death, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk