Category Archives: Food Microbiology Research

Research – Microbiological Quality of Nuts, Dried and Candied Fruits, Including the Prevalence of Cronobacter spp.

Posted on July 17, 2021 by | Leave a comment

MDPI

Cronobacter genus bacteria are food-borne pathogens. Foods contaminated with Cronobacter spp. may pose a risk to infants or immunocompromised adults. The aim of this study was to determine the microbiological quality of nuts, seeds and dried fruits with special emphasis on the occurrence of Cronobacter spp. Analyses were carried out on 64 samples of commercial nuts (20 samples), dried fruits (24), candied fruits (8), seeds (4), and mixes of seeds, dried fruits and nuts (8). The samples were tested for the total plate count of bacteria (TPC), counts of yeasts and molds, and the occurrence of Cronobacter spp. Cronobacter isolates were identified and differentiated by PCR-RFLP (Polymerase Chain Reaction – Restriction Fragments Length Polymorphism) and RAPD-PCR (Random Amplified Polymorphic DNA by PCR) analysis. TPC, and yeasts and molds were not detected in 0.1 g of 23.4%, 89.1%, and 32.8% of the analyzed samples. In the remaining samples, TPC were in the range of 1.2–5.3 log CFU g−1. The presence/absence of Cronobacter species was detected in 12 (18.8%) samples of: nuts (10 samples), and mixes (2 samples). The 12 strains of Cronobacter spp. included: C. sakazakii (3 strains), C. malonaticus (5), and C. turicensis (4). The results of this study contribute to the determination of the presence and species identification of Cronobacter spp. in products of plant origin intended for direct consumption. View Full-Text

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Posted in Cronobacter sakazakii, cross contamination, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

USA – CDC announces 208 confirmed Cyclospora cases with no clear common source

Posted on July 16, 2021 by | Leave a comment

Food Poison Journal

220px-Cyclospora_cayetanensis_stained

As of July 13, 2021, 208 laboratory-confirmed cases of cyclosporiasis in people who had no history of international travel during the 14-day period before illness onset have been reported to CDC by 23 jurisdictions, including 22 states and New York City.

The median illness onset date is June 17, 2021 (range: May 1, 2021–July 3, 2021).

At least 21 people have been hospitalized; no deaths have been reported.

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Posted in Cyclospora, Cyclosporiasis, food bourne outbreak, food contamination, Food Hazard, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Safety, Food Safety Alert, foodborne outbreak, foodbourne outbreak, outbreak, Parasite, Protozoan

Hong Kong – Risk Assessment Studies (Food Microbiology) – Siu-Mei

Posted on July 15, 2021 by | Leave a comment

CFS

Microbiological Quality of Roast Meats when They are Kept at Ambient Temperature for a Prolonged Period of Time

Microbiological Quality of Roast Meats when They are Kept at Ambient Temperature for a Prolonged Period of Time

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Posted in Center for Food Safety, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Safety, Food Safety Alert, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations

Research – Consumer Knowledge and Behaviors Regarding Food Safety Risks Associated with Wheat Flour

Posted on July 14, 2021 by | Leave a comment

Journal of Food Protection

Consumers do not consider flour, a low-moisture food product, a high risk for microbial contamination. In the past 10 years, however, flour has been identified as a source of pathogenic bacteria, including Salmonella and Escherichia coli. Online surveys were conducted to study consumers’ flour handling practices and knowledge about food safety risks related to flour. The survey also evaluated message impact on three food safety messages in communicating information and convincing consumers to adopt safe flour handling practices. Flour-using consumers (n = 1,045) from the United States reported they used flour to make cakes, cookies, and bread. Most consumers stored flour in sealed containers. Less than 1% kept a record of product identification numbers, such as lot numbers, and less than 11% kept brand and use-by date information. Many consumers (85%) were unaware of flour recalls, or outbreaks, and few (17%) believed they would be affected by flour recalls or outbreaks. If the recall affected the flour they bought, nearly half of the consumers (47%) would buy the same product from a different brand for a few months before they returned to the recalled brand. Among consumers who use flour to bake, 66% said they ate raw cookie dough or batter. Raw dough “eaters” were more difficult to convince to avoid eating and playing with raw flour than “noneaters.” Food safety messages were less impactful on those raw dough eaters than noneaters. Compared with the food safety message with only recommendations, those messages with recommendations and an explanation as to the benefits of the practice were more effective in convincing consumers to change their practices. These findings provide insight into effective consumer education about safe flour handling practices and could assist in the accurate development of risk assessment models related to flour handling.

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Posted in E.coli, food contamination, food handler, Food Hazard, Food Hygiene, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, food recall, Food Safety, Food Safety Alert, Pathogen, pathogenic, Research, Salmonella

Research – Getting Inside Salmonella’s Survival Strategies

Posted on July 12, 2021 by | Leave a comment

Technology Networks

kswfoodworld Salmonella

Our cells fight microbial invaders by engulfing them into membrane sacs – hostile environments in which pathogens are rapidly destroyed. However, the pathogen Salmonella enterica, which grows and reproduces inside our cells, has evolved ways to detoxify such hostile compartments, turning them into a comfortable home where Salmonella can survive and thrive.

A team of scientists led by EMBL group leader Nassos Typas has uncovered new details of Salmonella’s survival strategies. The researchers analysed protein interactions in Salmonella-infected cells to identify the diverse biological processes of the host cell that the bacterium uses. Salmonella targets and modifies cellular protein machineries and pathways, in which multiple proteins work together, with the help of so-called effector proteins, which it injects into host cells. Altogether, Salmonella is known to release more than 30 effector proteins into infected cells to hijack nutrients and protect itself. However, the functions of many of these proteins, and which host cell proteins they interact with, are largely unknown.

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

USA – FSIS Guideline for Controlling Campylobacter in Raw Poultry

Posted on July 12, 2021 by | Leave a comment

FSIS USDA

GUIDELINE IDFSIS-GD-2021-0006
ISSUE DATEJuly 2021

Replaces: The Campylobacter part of the 2015 FSIS Guideline for Controlling Salmonella and Campylobacter in Raw Poultry

This guideline helps poultry establishments, including those that are small and very small, identify and implement pre- and post-harvest interventions to control Campylobacter as part of their HACCP system. Additionally, it helps poultry establishments utilizes microbial testing results to monitor the performance of the HACCP system and inform decision making. This guideline relates to 9 CFR 381, 416, and 417.

Disclaimer: The contents of this guidance document do not have the force and effect of law and are not meant to bind the public in any way. This document is intended only to provide clarity to the public regarding existing requirements under the law or agency policies.

Full Guideline

FSIS-GD-2021-0006

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Posted in Campylobacter, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

USA – FSIS Guideline for Controlling Salmonella in Raw Poultry

Posted on July 12, 2021 by | Leave a comment

FSIS USDA

GUIDELINE IDFSIS-GD-2021-0005
ISSUE DATEJuly 2021
Replaces: The Salmonella part of the 2015 FSIS Guideline for Controlling Salmonella and Campylobacter in Raw Poultry

This guideline helps poultry establishments, including those that are small and very small, to identify and implement pre- and post-harvest interventions to control Salmonella as part of their HACCP system. Additionally, the guideline helps poultry establishments utilize microbial testing results to monitor the performance of the HACCP system and inform decision-making. This guideline relates to 9 CFR 381, 416, and 417.

Disclaimer: The contents of this guidance document do not have the force and effect of law and are not meant to bind the public in any way. This document is intended only to provide clarity to the public regarding existing requirements under the law or agency policies.

Full Guideline

FSIS-GD-2021-0005

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Posted in Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Salmonella, Salmonella in Chicken

Research- Predictive microbial modeling of E. faecium NRRL B-2354 inactivation during baking of a multi-component low-moisture food

Posted on July 11, 2021 by | Leave a comment

Journal of Food Protection

Validating baking ovens as a microbial kill step, using thermal inactivation models, is desirable; however, traditional isothermal models may not be appropriate for these dynamic processes, yet they are being used by the food industry. Previous research indicates that the impact of additional process conditions, such as process humidity, should be considered when validating thermal processes for the control of microbial hazards in low-moisture foods. In this study, the predictive performance of traditional and modified thermal inactivation kinetic models accounting for process humidity were assessed for predicting bacterial inactivation of Enterococcus faecium NRRL B-2354 in a multi-ingredient composite food during baking. Ingredients (milk powder, protein powder, peanut butter, and whole wheat flour), individually inoculated to ~6 logCFU/g and equilibrated to a water activity of 0.25, were mixed to form a dough. An isothermal inactivation study was conducted for the dough to obtain traditional D- and z- values (n=63). In a separate experiment, cookies were baked under four dynamic heating conditions: 135℃/high humidity, 135℃/low humidity, 150℃/high humidity, and 150℃/low humidity. Process humidity measurements, time-temperature profiles for the product core, surface, and bulk air, and microbial survivor ratios were collected for the four conditions at six residence times (n=144). The traditional isothermal model had a poor root mean square error (RMSE) of 856.51 log (CFU/g), significantly overpredicting bacterial inactivation during the process. The modified model accounting for the dynamic time-temperature profile and process humidity data yielded a better predictive performance with a RMSE of 0.55 log CFU/g. The results demonstrate the importance of accounting for additional process parameters in baking inactivation models, and that model performance can be improved by utilizing model parameters obtained directly from industrial-scale experimental data.

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Posted in Enterococcus, Enterococcus faecium, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Predictive Modelling, Research, Technology

Research – Sachet water consumption as a risk factor for cholera in urban settings: Findings from a case control study in Kinshasa, Democratic Republic of the Congo during the 2017–2018 outbreak

Posted on July 11, 2021 by | Leave a comment

PLOS One

Food Illness

Cholera is a diarrheal disease caused by ingestion of the Vibrio cholerae bacterium. Outbreaks in urban areas are becoming increasingly frequent in Sub-Saharan Africa. Risk factors for cholera have been studied in rural settings but not sufficiently in urban areas. Understanding context-specific risk factors is key for successful outbreak response. During a cholera outbreak in Kinshasa, the Democratic Republic of the Congo we were able to identify a previously unknown behavioural risk factor of particular relevance in urban settings–the consumption of drinking water from plastic sachets. Water sachets are sold on the streets of all major cities in Sub-Saharan Africa. It requires biting off an edge and sucking out the water, and we think that external contamination of these sachets was an important transmission route in the Kinshasa outbreak. Water sachets are predominantly consumed by socio-economically disadvantaged groups who lack piped water supply in their homes and have poor access to sanitary infrastructure. This makes our findings particularly relevant because these are the very populations who are at increased risk of getting and transmitting cholera. Health messaging and response measures should include consumption of water sachets as a potential risk factor during future cholera outbreaks in urban low-resource settings.

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Posted in Contaminated water, food bourne outbreak, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, foodborne outbreak, foodbourne outbreak, microbial contamination, Microbiology, outbreak, Research, Vibrio, Vibrio cholera, Water, water microbiology, Water Safety

Research – Strain variability in growth and thermal inactivation characteristics of Listeria monocytogenes strains after acid adaptation

Posted on July 11, 2021 by | Leave a comment

Journal of Food Protection

Listeria kswfoodworld food safety food poisoning

Image CDC

Given the importance of strain variability to predictive microbiology and risk assessment, the present study aimed to quantify the magnitude of strain variability in growth and thermal inactivation kinetics behaviors after acid adaptation. Thirty-three Listeria monocytogenes strains were exposed to acid-adapted tryptic soy broth with yeast extract and nonacid-adapted TSB-YE (pH 7.0) for 20 hours. Then, the growth parameters of these adapted and non-adapted strains that grew in non-buffered TSB-YE at 25℃ were estimated. The tested strains were inactivated at 60°C in non-buffered broth to obtain the heat resistance parameters. The results revealed that strain variability was present in the growth and thermal inactivation characteristics. The maximum specific growth rate ( μ max ) ranged within 0.21-0.44 and 0.20-0.45 h -1 after acid and non-acid adaptation, respectively. The lag times ( λ ) were 0.69-2.56 and 0.24-3.36 hours for acid-adapted and non-acid adapted cells, respectively. The apparent D -values at 60°C ( D 60 -values) of the pathogen ranged within 0.56-3.93 and 0.52-3.63 minutes for the presence and absence of acid adaptation condition, respectively. Acid adaptation increased the magnitude of strain variability in the thermal inactivation characteristics of the organism ( P <0.05), with the coefficient of variation (CV) increasing to 0.17, while acid adaptation did not significantly influence the variabilities in the growth parameters of the tested strains ( P ≥0.05). Furthermore, the subsequent growth behaviors of all strains did not exhibit significant changes ( P >0.05) after exposure to acidic broth. However, the thermal resistance of most of the tested strains (25/33) increased ( P <0.05) after growing in acid-adapted broth. The relevant data generated in the present study can be used to describe the strain variability in predictive microbiology, and deeply understand the behavior responses of different strains to acid adaptation.

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Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research