Category Archives: Food Microbiology Research

Research – Surveillance and source tracking of foodborne pathogens in the vegetable production systems of India

Posted on March 20, 2024 by | Leave a comment

Science Direct

Abstract

Fresh vegetables are prone to foodborne pathogen infection due to improper cultivation methods and poor post-harvest handling practices. This paper describes the prevalence of foodborne pathogens in three vegetables (tomato, brinjal, and lablab) cultivated by small-scale producers of India. We assessed the possible entry of pathogens into the vegetable production chain. Samples from soil, manure, irrigation water, harvesting bins, and workers’ hands were assessed as sources of possible pathogen entry. In addition, further sampling was done to determine prevalence of these pathogens in the produce from the agricultural fields and markets. Total plate counts, yeast and mold count, total coliforms like general microbial indices, and possible foodborne pathogens like Salmonella, Escherichia coli O157, Staphylococcus aureus, Pseudomonas aeruginosa, and Norovirus were assessed in all the samples by standard microbiological, biochemical, and molecular methods. The results revealed that among the three vegetables we studied, brinjal had the highest load of general microbial indicators. Moreover, the total coliforms count of market vegetables was higher than that of on-farm vegetables, indicating poor hygiene in post-harvest operations. The pathogen Pseudomonas aeruginosa was found in the market tomatoes (0.35 log10 cfu/g), and E. coli was detected in the market samples of brinjal (2.98–3.89 log10 cfu/g) and lablab (0.59–2.21 log10 cfu/g), thereby revealing fecal cross-contamination during pre or post-harvest operations. None of the vegetable samples were contaminated with E. coli O157:H7, Staphylococcus aureus, Salmonella sp., and norovirus. However, the microbiological source tracking of primary production farms showed that E. coli O157:H7 was present in manure (9/27), soil (6/27), harvest bins (6/27), and irrigation water samples (3/27) of SSP farms. In addition, soil (33%), manure (11%), and harvest bins (11%) had Pseudomonas aeruginosa. In conclusion, our study suggests that adequate knowledge of good agricultural practices for small-scale producers to cultivate microbiologically safe vegetable production and proper handling strategies for vegetable vendors is crucial to mitigate foodborne pathogen outbreaks through fresh vegetables.

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Posted in Coliforms, E.coli O157, E.coli O157:H7, Food Microbiology Research, Food Pathogen, mold, Mould/Mold, Norovirus, Pathogen, pathogenic, Pseudomonas, Pseudomonas aeruginosa, Research, Salmonella, TVC

Research – Prevalence, identification and antimicrobial resistance of Listeria monocytogenes and Listeria spp. isolated from poultry and pork meat

Posted on March 19, 2024 by | Leave a comment

IFST

The aim of this work was to evaluate the prevalence of Listeria monocytogenes and other Listeria spp. in chicken, duck, quail, turkey and pork meat, including the antibiotic resistance of isolated strains. A total of 184 meat samples were collected from different retailers in La Rioja (Spain). The presence of Listeria spp. and L. monocytogenes were detected in 24.46% and 10.32% of the meat samples respectively. L. monocytogenes was the predominant Listeria spp. found in chicken, quail and pork meat, while L. innocua and L. welshimeri were the predominant species in duck and turkey meat respectively. A total of thirty-three strains (55.93%) of Listeria spp. were found to be multi-resistant (resistant to ≥3 families of antibiotics). The highest multi-resistant rates were observed in L. monocytogenes (73.68%) and L. innocua (70.59%), followed by L. ivanovii (50%). Resistance to ampicillin and trimethoprim–sulfamethoxazole were found in L. monocytogenes strains isolated from chicken, being of special concern, since these antibiotics are used in the treatment of listeriosis. Special measures should be taken to reduce meat contamination such as adequate handling, correct preparation (cooking) and cleaning and disinfection in order to avoid cross-contamination.

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Posted in antimicrobial resistance, Antimicrobials, Food Microbiology Research, Listeria, Listeria monocytogenes, Research

Research – Using Essential Oils to Reduce Yersinia enterocolitica in Minced Meat and in Biofilms

Posted on March 19, 2024 by | Leave a comment

MDPI

Abstract

Yersiniosis, one of the leading foodborne infections in the European Union, is caused by Yersinia enterocolitica. In this study, the antibacterial and antibiofilm effects of cinnamon (Cinnamomum zeylanicum Nees), clove (Syzygium aromaticum L.), oregano (Origanum vulgare L.), rosemary (Rosmarinus officinalis L.), thyme (Thymus vulgaris L.), and winter savory (Satureja montana L.) essential oils were investigated against Y. enterocolitica strains belonging to the bioserotype 4/O:3. Cinnamon essential oil showed the highest antibacterial activity, with an MIC value 0.09 µL/mL, followed by oregano and thyme essential oils, with MIC values from 0.09 to 0.18 µL/mL, and from 0.18 to 0.23 µL/mL, respectively. Thyme essential oil at 0.23 µL/g (MIC) and at 0.46 µL/g (2MIC) significantly (p < 0.05) reduced the number of Y. enterocolitica by 0.38 log CFU/g and 0.64 log CFU/g, respectively, in minced pork meat during storage at 4 °C for 4 days. The Y. enterocolitica strains formed biofilms at 15 °C and 37 °C in tryptic soy broth and Luria–Bertani broth, while no biofilms were obtained at 5 °C, and in meat broth nutrient media. Applying the minimum bactericidal concentrations of cinnamon, clove, oregano, rosemary, thyme, and winter savory essential oils on preformed biofilms led to significant reductions being observed in the range from 45.34% to 78.89%. A scanning electron microscopy assay showed the devastating impact of oregano and thyme essential oils on the morphology of Y. enterocolitica bacterial cells. In conclusion, the results of this study show that essential oils possess high anti-Yersinia and antibiofilm effects.

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Posted in Biofilm, essential oils, Food Microbiology Research, Research, Yersinia, yersinia enterocolitica

Research – Low-Temperature Plasma used to remove E. coli from hydroponically grown crops

Posted on March 18, 2024 by | Leave a comment

Science Daily

A group led by researchers at Nagoya University and Meijo University in Japan has developed a disinfection technology that uses low-temperature plasma generated by electricity to cultivate environmentally friendly hydroponically grown crops. This innovative technology sterilizes the crops, promoting plant growth without the use of chemical fertilizers. Their findings appeared in Environmental Technology & Innovations.

In hydroponic agriculture, farmers cultivate plants by providing their roots with a nutrient solution.

However, the nutrient solution can become infected with pathogenic E. coli strains, contaminating the crop and leading to foodborne illnesses.

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

Nontyphoidal Salmonella Outbreaks Associated With Chocolate Consumption: A Systematic Review

Posted on March 17, 2024 by | Leave a comment

Journals LWW

Abstract

Background:

A large, cross-border outbreak of nontyphoidal salmonellosis connected to chocolate product consumption was recently reported. This occurrence motivated us to conduct a comprehensive review of existing literature concerning outbreaks of nontyphoidal salmonellosis associated with chocolate consumption.

Methods:

We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO CRD42022369023) in 3 databases: U.S. National Library of Medicine, Web of Science and Excerpta Medica. Google Scholar and the bibliography of each identified report were also screened. Eligible were articles published after 1970, describing outbreaks of more than 10 patients with a nontyphoidal salmonellosis associated with chocolate consumption.

Results:

Twenty-three articles were included, which described 12 outbreaks involving a total of 3266 patients. All outbreaks occurred in high-income countries: 1 was limited to 1 city, 6 involved 1 country and the remaining 5 involved 2 or more countries. Six outbreaks peaked in winter, 3 in autumn, 2 in spring and 1 in summer. Children were mainly affected. No predominant serotype was identified.

Conclusions:

Our data documents that chocolate is an optimal medium for the transmission of nontyphoidal salmonellosis. A connected worldwide reporting system including high-income, middle-income and low-income countries is crucial to detect infectious diseases outbreaks in an early phase and avoid their spread.

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Posted in Food Microbiology Research, Research, Salmonella, Salmonella in Chocolate

Research – Controlling Clostridium sporogenes spoilage of “requeijão cremoso” processed cheese: Modelling the growth/no-growth probability as a function of pH, sodium chloride and nisin

Posted on March 17, 2024 by | Leave a comment

Science Direct

Abstract

Predictive models were developed to assess the growth response of Clostridium sporogenes in “requeijão cremoso” processed cheese, as affected by pH and sodium chloride and nisin concentrations. A complete factorial design was performed using different formulations: pH (5.2, 5.6, and 6.0), sodium chloride (0.5, 0.75, 1.0, 1.25, and 1.5%), and nisin (0.0, 5.0, 7.5, 10.0 and 12.5 mg/kg), totalizing 75 conditions. Packs with 150g of “requeijão cremoso” were inoculated with 103 spores/g following storage at 10 °C for up to 60 days. The counts of C. sporogenes were performed on day zero and at the end of storage after a heat shock (80 °C for 12 min). The formulations that allowed an increase in the population >1 log CFU/g were assigned the value of 1 (growth), and the formulations in which the increase was <l log CFU/g were assigned 0 (no growth). Overall, the growth of C. sporogenes was affected by pH, salt concentration and nisin, e.g. at pH 5.2 the growth/no growth limit is 1.25% salt and no nisin, at pH 5.6 this limit is reduced to 0.75% salt, while at pH 6.0 only the effect of pH was sufficient to inhibit C. sporogenes even in the absence of salt and nisin. All isolated parameters and their combinations significantly affected spore germination, indicating that the model generated significantly contributes to the optimization of the processing and mitigation of the microbiological spoilage of “requeijão cremoso” processed cheese by Clostridia.

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Posted in Clostridium, Clostridium sporogenes, Food Microbiology Research, Food Technology, Research, Technology

Research – Measures for the control of Campylobacter spp. in chicken meat.

Posted on March 16, 2024 by | Leave a comment

FAO

Scope and objectives
In response to a request from the 52nd Session of the Codex Committee on Food
Hygiene (CCFH), the Joint FAO/WHO Expert Meeting on Microbiological Risk
Assessment (JEMRA) convened a meeting in Rome, Italy from 6 to 10 February
2023, to collate and assess the most recent scientific information relevant to the
control of thermotolerant Campylobacter species C. jejuni and C. coli (hereafter
Campylobacter) in broiler production and chicken meat, including a review of
the Codex Guidelines for the Control of Campylobacter and Salmonella in Chicken
Meat (CXG 78-2011).1
The scope was focused on aspects of broiler primary production from the point of
chick placement into production establishments to consumer handling.
The objectives were to identify and assess control measures for Campylobacter in
the broiler production chain. The expert committee reviewed the available data
on Campylobacter control including scientific literature published from 2008 to
October 2022 and data submitted in response to a call for data for this meeting. The
experts:

1) determined the quality and quantity of evidence of control measures
for Campylobacter,

2) evaluated the impact of measures to control Campylobacter
in the broiler production chain,

3) determined which hazard-based interventions
pertained specifically to Campylobacter and which were general to the control
of foodborne pathogens in the pre- and post-harvest broiler production chain,
and

4) reviewed and recommended revisions to the Guidelines for the Control of
Campylobacter and Salmonella in Chicken Meat (CXG 78-2011), paragraphs 1 to
115, based on the currently available scientific evidence (Annex 3).
Control measure evaluation began at the time of chick placement since there
is currently no evidence that parent flocks or hatchery practices contribute to
the colonization of broiler chicks. The available literature on interventions was
predominantly based on laboratory and pilot studies, with few commercial
scale applications; therefore, limited conclusions could be reached. The experts
recommend the use of a combination of multiple interventions approach) suitable to production and processing stages to lower Campylobacter contamination on chicken me

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Posted in Campylobacter, campylobacter coli, Campylobacter jejuni, Food Microbiology Research, Research

Research – Inhibition of Salmonella enteritidis in homemade mayonnaise using oregano essential oil (Origanum vulgare)

Posted on March 16, 2024 by | Leave a comment

Research Gate

The potential of oregano essential oil (OEO) as a natural antimicrobial agent to mitigate Salmonella spp. contamination in homemade mayonnaise made from raw eggs should be explored. This study aimed to assess the viability of Salmonella Enteritidis in homemade mayonnaise supplemented with OEO while also examining key quality parameters, including pH, titratable acidity, and the count of mesophilic aerobic microorganisms. In vitro experiments determined the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of OEO against two strains of Salmonella Enteritidis and one of Salmonella Typhimurium. Subsequently, homemade mayonnaise, intentionally contaminated with a Salmonella Enteritidis strain, was prepared, and OEO was added at concentrations of 0.5% and 1.0%. Bacterial plate counts for Salmonella spp. and mesophilic microorganisms, as well as acidity levels, were assessed at 0, 4, 8, and 24 hours of incubation at 30°C. The results indicated the in vitro efficacy of OEO, with an MIC of 0.5% and an MBC of 0.0625% against all strains. However, in homemade mayonnaise, Salmonella counts averaged 6.0 log CFU/g over the 24 hours at 30°C. Mesophilic microorganism counts also averaged 6.0 log CFU/g over 24 hours, similar to those of Salmonella. The pH values ranged from 4.5 to 5.1, and acidity levels remained between 0.31% and 0.39% throughout the 24 hours. In conclusion, oregano essential oil exhibited a bacteriostatic effect, effectively limiting the growth of Salmonella Enteritidis in homemade mayonnaise at the evaluated concentrations and time intervals.

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Posted in Food Microbiology Research, Research, Salmonella, Salmonella in Eggs

Ireland – Guidance on Management of Norovirus for Shellfish Producers

Posted on March 15, 2024 by | Leave a comment

SFPA

Introduction:
Norovirus (NoV), commonly known as the “winter vomiting bug”, is a significant cause of acute gastroenteritis often causing diarrhoea and vomiting. The virus is transmitted through the consumption of food or water contaminated with faecal matter or through contact with infected individuals or surfaces. It is prevalent in the community and can be present in discharges from even advanced wastewater treatment systems, which may not entirely eliminate NoV.
Bivalve molluscs such as oysters are known to accumulate and concentrate NoV. This poses a particular health risk as these shellfish are often consumed raw or lightly cooked, making them a potential source of infection.

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Posted in Food Microbiology Research, Norovirus, Research

USA – FDA Advises Restaurants and Retailers of a Recall of Certain Oysters from Westport, Connecticut Potentially Contaminated with Norovirus

Posted on March 15, 2024 by | Leave a comment

FDA

Food Borne Illness - Norovirus -CDC Photo

March 14, 2024

Audience

  • Restaurants and food retailers in Connecticut (CT), Florida (FL), Georgia (GA), Maine (ME), Maryland (MD), Massachusetts (MA), Minnesota (MN), New Jersey (NJ), Ohio (OH), Rhode Island (RI), South Carolina (SC) and Texas (TX) that have recently purchased oysters from Norm Bloom and Son (CT-069-SS, AQ), harvested from Westport, CT, lot 207, with the harvest date 2/20/2024.
  • Consumers in CT, FL, GA, MA, MD, ME, MN, NJ, OH, RI, SC, and TX who have recently purchased oysters from Norm Bloom and Son (CT-069-SS, AQ), harvested from Westport, CT, lot 207, with the harvest date 2/20/2024.

Product

Recalled oysters are from Norm Bloom and Son (CT-069-SS, AQ), harvested from Westport, CT, lot 207, with the harvest date 2/20/2024. The oysters were distributed to restaurants and retailers in CT, FL, GA, MA, MD, ME, MN, NJ, OH, RI, SC, and TX, and may have been distributed to other states as well.

Purpose

The FDA is notifying restaurants, food retailers, and consumers that the Connecticut Department of Agriculture, Bureau of Aquaculture is conducting a recall of oysters harvested by Norm Bloom and Son (CT-069-SS, AQ) from Westport, CT, lot 207, with the harvest date 2/20/2024, because they are associated with a norovirus outbreak in Minnesota and may be contaminated with norovirus. The FDA is advising restaurants and food retailers not to serve or sell and consumers not to eat the recalled oysters.

Shellfish contaminated with norovirus can cause illness if eaten, and potentially severe illness in people with compromised immune systems. Food containing norovirus may look, smell, and taste normal. Consumers of these products who are experiencing symptoms of illness should contact their healthcare provider and report their symptoms to their local Health Department. Diarrhea, abdominal cramps, nausea, vomiting, and fever may be associated with gastroenteritis infections caused by this organism.

Symptoms of Norovirus

People of all ages can get infected and sick with norovirus. The most common symptoms of norovirus are diarrhea, vomiting, nausea, and stomach pain. Other symptoms include fever, headache, and body ache.

A person usually develops symptoms 12 to 48 hours after being exposed to norovirus. Most people with norovirus illness get better within 1 to 3 days.

If you have norovirus illness, you can feel extremely ill, and vomit or have diarrhea many times a day. This can lead to dehydration, especially in young children, older adults, and people with other illnesses. Symptoms of dehydration include decrease in urination, dry mouth and throat, and feeling dizzy when standing up. Children who are dehydrated may cry with few or no tears and be unusually sleepy or fussy.

If you think you or someone you are caring for is severely dehydrated, call your healthcare provider

Summary of Problem and Scope

The Connecticut Department of Agriculture, Bureau of Aquaculture is conducting a recall of oysters from Norm Bloom and Son (CT-069-SS, AQ), harvested from Westport, CT, lot 207, with the harvest date 2/20/2024, because they are associated with a norovirus outbreak in Minnesota and may be contaminated with norovirus. The oysters were distributed to restaurants and retailers in CT, FL, GA, MA, MD, ME, MN, NJ, OH, RI, SC, and TX, and may have been distributed to other states as well. The FDA is advising consumers not to eat, and restaurants and food retailers not to sell, and to dispose of these oysters.

Contaminated oysters can cause illness if eaten raw, particularly in people with compromised immune systems. Food contaminated with norovirus may look, smell, and taste normal. Consumers of these products who are experiencing symptoms of norovirus illness should contact their healthcare provider, who should report their symptoms to their local Health Department.

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Posted in Food Microbiology Research, Norovirus, Norovirus Oysters, Research