Category Archives: Microbiology Investigations

Research – Survival of Salmonella Typhimurium and Escherichia coli O157:H7 on blueberries and impacts on berry quality during 12 weeks of frozen storage after washing with combinations of sodium dodecyl sulfate and organic acids or hydrogen peroxide

Posted on January 2, 2022 by | Leave a comment

Wiley Online

Salmonella spp. and Escherichia coli are well tolerant of freezing. This study was to investigate survival of the foodborne pathogens during storage at −18 ± 2°C for 12 weeks on blueberries after washing with: 500 ppm acetic acid plus 5,000 ppm sodium dodecyl sulfate (SDS) (AA/SDS), 20 ppm peroxyacetic acid plus 5,000 ppm SDS (PPA/SDS), or 200 ppm hydrogen peroxide plus 5,000 ppm SDS (H2O2/SDS), when compared with findings from no wash, or wash with water, 80 ppm PPA or 200 ppm chlorinated water. Following a 60 s contact with one of the three new solutions, the treatments showed 3.3–3.9 log10 CFU/g reductions in Salmonella Typhimurium and E. coli O157:H7 counts. After 2 weeks of frozen storage, 3.9–4.2 log10 CFU/g reductions of Salmonella and E. coli were observed. After 12 weeks of frozen storage, Salmonella and E. coli survivors were below detection limits (0.39 log10 CFU/g) in berries washed with new solutions. The frozen storage had a significant impact (p < .05) on microbial counts of both treated and nontreated blueberries. Although none of these washings decreased the total phenolic and anthocyanins contents and apparent quality at time 0, frozen storage caused significant damage on the texture of both treated and nontreated blueberries. Interestingly, no significant decrease in the total phenolic, anthocyanins content, and apparent quality was observed during the 12-week frozen storage. The counts of total bacteria, yeasts, and molds decreased throughout storage for treated and untreated berries. This demonstrates that the three wash solutions enhance the safety of frozen berries.

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Posted in Decontamination Microbial, E.coli, E.coli O157, E.coli O157:H7, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Salmonella

Research – Effect of domestic freezing on the viability of Toxoplasma gondii in raw and dry-cured ham from experimentally infected pigs

Posted on January 1, 2022 by | Leave a comment

Journal of Food Protection

Toxoplasma gondii is the causative agent of the parasitic disease toxoplasmosis, which is an important food borne zoonosis. Eating undercooked meat of infected animals has been considered the major transmission route of T. gondii to humans. The present study evaluates the efficacy of domestic freezing on the inactivation of T. gondii bradyzoites in raw and dry-cured ham. Meat (raw and dry-cured ham) of a pig experimentally orally inoculated with 4,000 oocysts of T. gondii VEG strain was subjected to domestic freezing of -20 ºC at different days. The effect was evaluated by bioassay in mice followed by qPCR. In raw ham and dry-cured ham, temperature of -20 ºC for 7 and 14 days respectively did not inactivate T. gondii . More studies are needed to find the right temperature and time needed to render the bradyzoites non-infectious for human. Meanwhile, the recommendations of freezing to inactivate T. gondii in raw or dry-cured meats must be revisited considered that it does not reduce the risk of infection.

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Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Parasite, Protozoan, Research, Toxoplasma gondii, Toxoplasmosis

EU – Europe Increases Checks on Melons after Salmonella Outbreak

Posted on December 30, 2021 by | Leave a comment

Food Safety News

The European Commission has tightened the rules around imports of Galia melons from Honduras because of a recent Salmonella outbreak.

Emergence of a risk to human health because of possible Salmonella Braenderup contamination means official controls are to be increased with identity and physical checks on 10 percent of consignments entering the EU beginning Jan. 6.

The multi-country outbreak of Salmonella Braenderup that affected more than 350 people was traced to Galia melons from Honduras. Four people were sick in the United States and two in Canada. The UK was the most affected but ill people were also from Sweden, Belgium, Germany, Denmark, Netherlands, Switzerland, Austria, Czech Republic, Finland, France, Ireland, Luxembourg and Norway.

A sample of Salmonella Braenderup that matched the outbreak strain was found on the surface of a washing tank in one of the Honduran facilities where Galia melons were packed. The harvest season started again this month.

However, authorities in Honduras said the cause cannot be confirmed to be Galia melons from the country because a case was reported in July 2021 in Denmark, and no melons from Honduras were exported at that time.

The updated regulation temporarily changes the rate of official controls and puts emergency measures on entry into the EU of certain goods from some non-EU countries. Rules are modified every six months to account for new information on risks to health and non-compliance with EU legislation.

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Posted in food bourne outbreak, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, foodborne outbreak, foodbourne outbreak, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, outbreak, Research, Salmonella

Research – A Naturally Derived Nanocomposite Film with Photodynamic Antibacterial Activity: New Prospect for Sustainable Food Packaging

Posted on December 30, 2021 by | Leave a comment

ACS

Abstract Image

Food packaging with efficient antibacterial ability is highly desirable and challenging in facing the crisis of microbial contamination. However, most present packaging is based on metal-based antibacterial agents and requires a time-consuming antibacterial process. Here, the unique packaging (CC/BB films) featuring aggregation-induced emission behavior and photodynamic inactivation activity is prepared by dispersing self-assembled berberine–baicalin nanoparticles (BB NPs) into a mixed matrix of sodium carboxymethylcellulose-carrageenan (CC). The superiority of this design is that this packaging film can utilize sunlight to generate reactive oxygen species, thus eradicating more than 99% of E. coli and S. aureus within 60 min. Also, this film can release BB NPs to inactivate bacteria under all weather conditions. Surprisingly, the CC/BB nanocomposite film presented excellent mechanical performances (29.80 MPa and 38.65%), hydrophobicity (117.8°), and thermostability. The nanocomposite film is validated to be biocompatible and effective in protecting chicken samples, so this work will provide novel insights to explore safe and efficient antibacterial food packaging.

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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, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Staphylococcus aureus, Technology

India – Apple puts India iPhone plant “on probation” after mass food poisoning

Posted on December 30, 2021 by | Leave a comment

CBS News

Some 250 women working at Foxconn’s iPhone factory in the southern Indian state of Tamil Nadu were treated for food poisoning this month. One-hundred-fifty-nine were hospitalized.

That prompted demonstrations against living conditions at company hostels that have kept the factory at Sriperumbudur, near Chennai, closed since December 18.

Apple said it has placed the plant “on probation” and is working with the supplier to rapidly implement “a comprehensive set of corrective actions.”

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

Research – ‘Jelly’ ice cubes could revolutionize cold storage and the safety of cold food

Posted on December 30, 2021 by | Leave a comment

Food Safety News

Researchers at the University of California-Davis have developed a new type of cooling cube with the potential, they say, to transform how cold storage is done.

The benefits of plastic-free, “jelly ice cubes” are that they do not melt, are compostable and antimicrobial, and can help prevent cross-contamination.

It can be easy for foodservice operators and their employees not to think about the food safety implications of how ice is used and handled. If they don’t take proper precautionary measures to handle food properly or keep up with necessary preventive maintenance measures to ensure that their ice machines are clean, sanitary and operating safely, there can be serious food safety risks. The researchers at the UC-Davis took note of this concern.

The researchers began working on their coolant cubes after Luxin Wang, an associate professor in the Department of Food Science and Technology, saw the amount of ice used at fish-processing plants and the cross-contamination that meltwater could spread among products or drains.

“The amount of ice used by these fish-processing sites is massive,” Wang said. “We need to control the pathogens.”

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Safety, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Technology

USA – FDA Core Table Update

Posted on December 30, 2021 by | Leave a comment

FDA

Five outbreaks still active, two with source still unidentified.

Date
Posted		 Reference
#		 Pathogen
 Product(s)
Linked to
Illnesses
(if any)		 Total
Case Count
12/29/2021 1052 E. coli O157:H7 Not Yet Identified 11
12/20/2021 1039 Listeria
monocytogenes		 Packaged Salad See Outbreak
Advisory
12/15/2021 1048 Listeria
monocytogenes		 Packaged Salad See Outbreak
Advisory
11/24/2021 1044 Salmonella

Javiana

 Not Yet
Identified		 60
11/17/2021 1043 E. coli
O157:H7		 Spinach See Outbreak
Advisory
9/15/2021 1031 Salmonella
Oranienburg		 Red, Yellow,
and White Onions		 See Outbreak
Advisory

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Posted in E.coli O157, E.coli O157:H7, FDA, food bourne outbreak, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, foodborne outbreak, foodbourne outbreak, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, outbreak, Salmonella, Salmonella Oranienburg

Research – Salmonella enterica 4,[5],12:i:- an emerging threat for the swine feed and pork production industry

Posted on December 29, 2021 by | Leave a comment

Journal of Food Protection

Salmonella continues to be a significant cause of foodborne illnesses in human medicine. The Centers for Disease Control and Prevention reported Salmonella as the second leading cause of foodborne illness in the United States, and the leading cause of both hospitalizations and deaths. Salmonella enterica 4,[5],12:i:- (STM) is a monophasic variant of S. Typhimurium and it is an emerging threat to both human and animal health. STM was first identified in the 1980’s from poultry products and has become increasingly prevalent in meat products including pork. STM has also been identified in swine farms as well as feed manufacturing environments and feed itself. Similar pulse-field gel electrophoresis profiles have been observed between human clinical cases and the STM samples originating from swine feed. These related profiles suggest a link between swine ingesting contaminated feed and the source of foodborne illness in human. The objective of this article was to better understand the history of STM and the possible pathway between swine feed to the household table. Continued research is necessary to better understand how STM can enter both the feed supply chain and the pork production chain to avoid contamination of pork products destined for human consumption.

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

India – 30 students of Pune institute fall ill, officials suspect food poisoning; probe underway

Posted on December 29, 2021 by | Leave a comment

Hindustan Times

The local block development officer said the students started complaining of stomach upset and nausea after eating certain food items for Christmas.

About 30 girls of a training institute in Pune, Maharashtra, fell ill due to suspected food poisoning after a Christmas dinner following which many of them had to be admitted to a hospital. An investigation is underway.

The incident happened at Nav Gurukul training centre of Flora Institute of Technology, Kusegaon in Bhor taluka. Local block development officer Vishal Tanpure said 31 students started complaining of stomach upset and nausea after eating some food items for Christmas.

Pune district civil surgeon Dr Ashok Nandapurkar said the girls had consumed food items made from paneer (Indian cottage cheese) for Christmas. “On Monday, some of them complained of stomach ache and nausea. A total of 22 girls have been taken to Bhor sub-district hospital. Of them seven are admitted and the rest are being treated at the OPD level. The remaining students have been taken to Sassoon hospital,” he said.

Officials said the condition of all 30 girls was stable, adding that necessary samples were being collected for examination. “The local administration has initiated the investigation and sent a team to collect food and water samples from the spot,” Tanpure was quoted as saying by news agency ANI.

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

Research – Comparisons of Non-thermal Decontamination Methods to Improve the Safety for Raw Beef Consumption

Posted on December 28, 2021 by | Leave a comment

Journal of Food Protection

The object of this study was to examine non-thermal treatments to reduce foodborne pathogens in raw beef. Foodborne-illness pathogens were inoculated in the raw beef. Death rates of foodborne illness pathogens were evaluated by non-thermal decontamination methods(high pressure processing at 500MPa[HPP] for 2min, 5min, and 7min; UV LED radiation at 405nm[UV LED] for 2h, 6h, and 24h; hypochlorous acid water at 100ppm[HAW] for 1min, 3min, and 5min; 2.5% lactic acid[LA] for 1min, 3min, and 5min; modified atmosphere that replaced O2 to CO2 [MAP] for 24h and 48​​h; bio-gel[BG] application for 24h and 48h. Quality characteristics were measured after applying the practical non-thermal decontamination methods. After the treatment of HPP for 7min, inactivity rates were 4.4-6.7Log CFU/g for E. coli, Salmonella, and L. monocytogenes and 1.7Log CFU/g for S. aureus (p <0.05). After the treatment with UV LED for 24h, the reduced cell counts were 0.5, 0.7, and 0.3Log CFU/g for E. coli , Salmonella , and S. aureus, respectively(p <0.05), but no significant reduction for L. monocytogenes. When the beef was treated with HAW was treated for 5min, 0.6Log CFU/g of E. coli, 0.5Log CFU/g of Salmonella, 0.4Log CFU/g of S. aureus , and 0.5Log CFU/g of L. monocytogenes were inactivated. After the beef was treated with LA for 5min, 1.8Log CFU/g of E. coli, 3.0Log CFU/g of Salmonella, 1.3Log CFU/g of S. aureus, and 1.9Log CFU/g of L. monocytogenes were inactivated. MAP for 48h caused the inactivation of 0.3Log CFU/g of E. coli, 0.1Log CFU/g of Salmonella. After treatment of BG for 48h, 0.3Log CFU/g of E. coli and 0.4Log CFU/g of Salmonella were significantly decreased(p <0.05). HPP cooked the beef after 2min of treatment. HAW and BG changed the surface color of the beef, LA reduced the pH of beef (p<0.05). However, UV LED did not cause any changes in the beef quality properties. These results indicates that UV LED can improve the food safety of raw beef.

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Posted in Decontamination Microbial, E.coli, 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, Salmonella