Category Archives: Research

Research – Combination of ultraviolet light‐C and clove essential oil to inactivate Salmonella Typhimurium biofilms on stainless steel

Posted on March 16, 2020 by | Leave a comment

Wiley Online

Abstract

Salmonella typhimurium is able to form biofilms as a resistance mechanism against antimicrobials; therefore, it represents a problem for assuring food safety and highlights the importance of research on anti‐biofilm technologies. In this study, S. typhimurium biofilms were inactivated with the combination of clove essential oil (CEO) and ultraviolet light (UV‐C). The volatile composition of the CEO determined by gas chromatography showed eugenol as the major constituent (82%). A combination of CEO with UV‐C achieved a complete bacterial reduction (6.8 log/cm2) on biofilms with doses of 1.2 mg/ml and 76.41 mJ/cm2, respectively. Individually, the CEO at 1.2 mg/ml caused a reduction of 1.8 log CFU/cm2 of attached bacteria cells on stainless steel, while UV‐C individually used at 620.4 mJ/cm2 caused a 2.9 log CFU/cm2 reduction compared to control biofilms. In conclusion, this study demonstrated a synergistic effect of combining CEO and UV‐C irradiation to inactivate biofilms of S. typhimurium.

 

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Posted in Biofilm, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiology, Research, Salmonella, Uncategorized

Research -Microbiological reduction strategies of irrigation water for fresh produce

Posted on March 15, 2020 by | Leave a comment

JFP

Irrigation water can be a source of pathogenic contamination of fresh produce. The quality of the water used during primary production is important to control to ensure food safety and protect human health. Several measures to control the microbiological quality of irrigation water are available for growers, including preventative and mitigation strategies. However, clear guidance for growers on which strategies could be used to reduce microbiological contamination is needed. This study evaluates pathogenic microorganisms of concern in fresh produce and water, the microbiological criteria of water intended for agricultural purposes, as well as preventative and mitigative microbial reduction strategies. This article provides suggestions for control measures that growers can take during primary production to reduce foodborne pathogenic contamination coming from irrigation water. Results show that controlling the water source, regime, and timing of irrigation may help to reduce the potential exposure of fresh produce to contamination. Moreover, mitigation strategies like electrolysis, ozone, UV, and photocatalysts hold promise either as a single treatment, with pretreatments that remove suspended material, or as combined treatments with another chemical or physical treatment(s). Based on the literature data, a decision tree was developed for growers, which describes preventative and mitigation strategies for irrigation water disinfection based on the fecal coliform load of the irrigation water and water turbidity. It helps guide growers when trying to evaluate possible control measures given the quality of the irrigation water available. Overall, the strategies available to control irrigation water used for fresh produce should be evaluated on a case-by-case basis as one strategy or technology does not apply to all scenarios.

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Posted in Boil Water Notice, Contaminated water, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiology, Research, Uncategorized, Water, water microbiology, Water Safety

Research – Inactivation of Shiga Toxin-Producing Escherichia coli and Listeria monocytogenes Within Plant Versus Beef Burgers in Response to High Pressure Processing

Posted on March 14, 2020 by | Leave a comment

JFP

kswfoodworld E.coli O157

Image CDC

We evaluated high pressure processing to lower levels of Shiga toxin-producing Escherichia coli (STEC) and Listeria monocytogenes inoculated into samples of plant or beef burgers. Multi-strain cocktails of STEC and L. monocytogenes were separately inoculated (ca. 7.0 log CFU/g) into plant burgers or ground beef. Refrigerated (i.e., 4°C) or frozen (i.e., -20°C) samples (25-g each) were subsequently exposed to 350 MPa for up to 9 or 18 min or 600 MPa for up to 4.5 or 12 min, respectively. When refrigerated plant or beef burger samples were treated at 350 MPa for up to 9 min, levels of STEC were reduced by ca. 0.7 to 1.3 log CFU/g. However, when refrigerated plant or beef burger samples were treated at 350 MPa for up to 9 min, levels of L. monocytogenes remained relatively unchanged (ca. ≤0.3 log CFU/g decrease) in plant burger samples, but were reduced by ca. 0.3 to 2.0 log CFU/g in ground beef. When refrigerated plant or beef burger samples were treated at 600 MPa for up to 4.5 min, levels of STEC and L. monocytogenes were reduced by ca. 0.7 to 4.1 and ca. 0.3 to 5.6 log CFU/g, respectively. Similarly, when frozen plant and beef burger samples were treated at 350 MPa up to 18 min, reductions of ca. 1.7 to 3.6 and ca. 0.6 to 3.6 log CFU/g in STEC and L. monocytogenes numbers, respectively, were observed. Exposure of frozen plant or beef burger samples to 600 MPa for up to 12 min resulted in reductions of ca. 2.4 to 4.4 log and ca. 1.8 to 3.4 log CFU/g in levels of STEC and L. monocytogenes, respectively. Via empirical observation, pressurization did not adversely affect the color of plant burger samples, whereas appreciable changes in color were observed in pressurized ground beef. These data confirm that time and pressure levels already validated for control of STEC and L. monocytogenes in ground beef will likely be equally effective towards these same pathogens in plant burgers without causing untoward effects on product color.

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Posted in E.coli, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, microbial contamination, Microbiology, Research, STEC, STEC E.coli, Uncategorized

Research – Some E. coli Strains May Be Linked to Development of Bowel Cancer

Posted on March 14, 2020 by | Leave a comment

Food Poisoning Bulletin

CDC E.coli

Image CDC

According to a new study in the journal Nature, E. coli infections may be linked to bowel cancer. Some species of the intestinal microbiota, which is the collection of bacteria and viruses that live in the human gut, have been associated with colorectal cancer, but a direct role hasn’t been proven.

As it turns out, E. coli bacteria carry what is called a pathogenicity island pks, that creates enzymes that synthesize a compound called colibactin. Colibactin causes double-strand breaks in cultured cells. This damage can lead to cancer over time. Colibactin is found more often in fecal samples of people who do have bowel cancer than healthy people.

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Posted in E.coli, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiology, Microbiome, Research, Uncategorized

Research -Towards a better understanding of listeriosis risk among older adults in the United States: Characterizing dietary patterns and the sociodemographic and economic attributes of consumers with these patterns

Posted on March 13, 2020 by | Leave a comment

JFP

Older adults are at higher risk of invasive listeriosis compared with the general population.  Some foods are more likely than others to be contaminated with or contain high levels of Listeria monocytogenes . The objectives of this study were to, 1) determine dietary consumption patterns, among older adults in the United States; 2) evaluate sociodemographic and economic characteristics of older adults associated with each pattern; 3) determine intake of foods associated with larger relative risk of listeriosis within these patterns; and 4) rank these patterns based on risk. Data of older adults, age 60 and older, participating in the cross-sectional National Health and Nutrition Examination Surveys (NHANES) 2009-2010, 2011-2012, and 2013-2014 (n=4,967) were included in these analyses. Cluster analysis was used to define dietary patterns based on day 1 and day 2 24-hour dietary recalls. Mean intake of foods associated with higher risk of listeriosis were examined within each pattern, and ANOVA with Dunnett’s method of adjustment was used to evaluate significant differences in mean intake of foods. Patterns were ranked based on relative risk of listeriosis using outbreak illness attribution data. Five distinct dietary patterns were identified. Patterns ranked at highest relative risk of listeriosis, based on US outbreak illness attribution data, were characterized by relatively higher intakes of, (1) fruits, vegetables, and cheeses (~13% respondents) or (2) cereal, milk, and yogurt (~14% respondents).  Individuals consuming these dietary patterns differed in sex, race, food security, self-rated diet quality, and self-rated health. Cluster analysis, despite methodological limitations, provides new information on consumption, sociodemographic, and economic characteristics of subgroups within susceptible populations that may be used to target educational messages .

 

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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, Microbiology, Research, Uncategorized

Research -New Monoclonal Antibody Treatment Takes Aim at Bacterial Biofilms

Posted on March 10, 2020 by | Leave a comment

Contagion Live

Microbial biofilms can present a variety of medical challenges by generating chronic infections, modulating host immune response, contaminating medical devices or environments, and facilitating the emergence of antimicrobial resistance.

Investigators at the Lewis Katz School of Medicine at Temple University have shown that a new monoclonal antibody treatment is able to break apart these communities of harmful bacteria, which could aid existing antibiotic treatments in more efficiently clearing out infections. Their research was published in Nature Communications.

The investigators tested a human monoclonal antibody with pan-amyloid-binding activity, mAb 3H3, against biofilms formed by Salmonella enterica serovar typhimurium.

The antibody was isolated from a healthy human subject. The study team was interested in 3H3’s ability to attach to β-amyloid.

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Posted in Biofilm, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Microbiology, Research, Salmonella, Uncategorized

New Zealand – New Zealand Food Safety sets significant new goal to reduce foodborne Campylobacter by 20 per cent by 2025

Posted on March 9, 2020 by | Leave a comment

MPI

campy2

Image CDC

Deputy director-general for New Zealand Food Safety Bryan Wilson announced today a new goal to significantly reduce foodborne Campylobacter poisoning by 20% by 2025.

“Campylobacter is the most common cause of notifiable foodborne illness in New Zealand. Symptoms can include stomach cramps, nausea, fever and diarrhoea, lasting for about a week.

“Contributing factors are Kiwis’ ever-increasing level of consumption of fresh chicken meat and the way we handle, prepare and cook poultry meat in New Zealand.

“Working with the poultry industry, New Zealand Food Safety’s risk management strategy has achieved more than a 50% reduction in foodborne cases since 2006. This is a substantial reduction and one that we could not have achieved without partnership and support from industry. But, the rate of gastrointestinal illness caused by this bug remains high,” says Mr Wilson.

“New Zealand Food Safety and industry continue to work collaboratively to reduce Campylobacter rates in the country with an updated strategy and action plan that includes enhanced consumer education, better hygiene through the poultry processing and food distribution chain, and improved measures at the poultry farm level,” says Mr Wilson.

New Zealand Food Safety commissioned the study to add a high level of scientific rigour to efforts to reduce foodborne illnesses, and the findings of the study Source assigned campylobacteriosis in New Zealand were also released today.

The results from the study found more than 80% of human foodborne cases are likely due to the consumption of poultry meat.

“The intensive 12-month study included interviews with 666 individuals who’d been infected with the bug.

“As well as identifying the sources of Campylobacter illnesses in humans, the study identified several factors that may increase the likelihood of an individual contracting the disease.

“We’ll continue our work with industry to drive down the level of Campylobacter in poultry by understanding where the bacteria enter the food chain and where cross-contamination is likely happening.

“It’s important consumers know how to prevent Campylobacter in the home by continuing to follow the advice on the New Zealand Food Safety web page Clean, Cook, Chill.

“Cooking chicken properly until the juices run clear and having good hygiene practises at home to prevent cross-contamination will minimise your risk to Campylobacter and other foodborne illnesses,” says Mr Wilson.

Source Assigned Campylobacteriosis in New Zealand Study (SACNZS) – Report [PDF, 5.4 MB]

Find out more about Campylobacter

Clean, Cook, Chill

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Posted in Campylobacter, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiology, Research, Uncategorized

Research – In vitro antimicrobial effects of Myristica fragrans essential oil on foodborne pathogens and its influence on beef quality during refrigerated storage

Posted on March 8, 2020 by | Leave a comment

Wiley Online

Nutmeg (Myristica fragrans) seed was subjected to the hydro‐distillation method to extract its essential oil (NEO). Its main constituents were α‐pinene (20.16%), sabinene (14.45%), and β‐pinene (13.26%) with great antimicrobial and antioxidant actions. A novel edible coating was then fabricated based on the sage seed mucilage (SSM) and NEO, to ameliorate the quality and shelf‐life of beef slices. The NEO‐loaded SSM coating was able to significantly decrease the population of total viable count, Escherichia coli, Staphylococcus aureus, psychrotrophic bacteria, and fungi. Moreover, lipid oxidation of beef slices was remarkably suppressed upon the application of bioactive NEO‐loaded SSM edible coating, as compared with the control by Day 6. The coated beef sample, especially NEO‐rich SSM coated ones perceived a higher consumer acceptance and firmness than the SSM coated and noncoated samples. The SSM edible coating containing NEO could therefore have the potential to control the growth of pathogenic microorganisms and lipid oxidation, and to improve the color stability and sensory properties of meat and meat products.

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Posted in Antimicrobials, E.coli, Food Micro Blog, Food Microbiology, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Research, Staphylococcus aureus, Uncategorized

Research – Biofilm-inhibition activities of fractions of Senna Siamea (LAM) Irwin & Barneby leaf against Escherichia coli

Posted on March 3, 2020 by | Leave a comment

Academic Journals ecoli

Escherichia coli has carved its niche in the urinary tract with the formation of a formidable matrix called biofilm. This biofilm is not only recalcitrant to the body’s immune system but also resistant to antibacterial agents. Senna siamea (Lam) Irwin and Barneby is a medicinal plant with established antibacterial effect against planktonic cells of many bacteria. An attempt was made herein to evaluate the effect of its leaf extract and fractions on biofilm of E. coli isolates. Crude extracts of leaf, stem bark and root of this plant were prepared using ethanol as the solvent for the cold extraction. Phytochemical screening was carried out on the three extracts. Two E. coli strains from different antenatal patients attending General Hospital, Kafanchan, Kaduna were donated to us by a researcher from Ahmadu Bello University, Zaria and the reference strain, E. coli, WDCM 00013 (from Germany) were tested for biofilm production using the Congo red method. Antimicrobial susceptibility testing of the crude extracts against the isolates was carried out using the agar diffusion method. The Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) were determined for the leaf extract of the plant using micro broth dilution and agar diffusion methods respectively. In order to establish the antibiofilm activities of the leaf extract of the plant, sub-inhibitory concentrations (sub-MIC) were used against the test isolates in the remaining assays in the work. Column chromatography backed by thin layer chromatography (TLC) was used to fractionate leaf extract (having the best antibacterial activity) of the plant, using different ratios of a combination of hexane, ethyl acetate and n-butanol as fractionating solvents. MIC and MBC of the leaf extract were and 50 mg/ml respectively. High values of percentage biofilm inhibition were observed against all the bacterial isolates from the antibiofilm assay. Combination of solvents in the increasing order of polarity enhanced the antibiofilm activity of the various fractions of the leaf extract of Senna siamea. In conclusion, further fractionation of Senna siamea leaf extract increases its antibiofilm activities.

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Posted in Biofilm, E.coli, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Microbiology, Research, Uncategorized

Research -Restaurants and takeaways cop blame for 60% of food poisoning cases

Posted on March 2, 2020 by | Leave a comment

Food Service Equipment Journal

According to the FSA, there are an estimated 380,000 cases of norovirus linked to food occur in the UK per year.

A breakdown of the roles of the main transmission pathways in food suggest eating out accounts for an estimated 37% of all foodborne norovirus cases and takeaways at 26%.

Open-headed lettuce on retail sale at 30%, raspberries on retail sale at 4%, and oysters on retail sale at 3% make up the remainder.

The revised foodborne norovirus estimate, combined with better analysis of how many illnesses of unknown cause are also likely to be caused by food, suggest around 2.4 million estimated UK cases of foodborne illness occur each year.

Professor Guy Poppy, chief scientific adviser to the Food Standards Agency, said: “This work gives us a much better idea of the role of food in the spread of all infectious intestinal disease in the UK. However, this does not mean more people are getting unwell, only that we estimate food is responsible for more existing cases than previously thought.

 

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Posted in food contamination, Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Safety, Food Testing, Food Virus, Norovirus, Research, Uncategorized, Virus