Category Archives: Decontamination Microbial

Research – Recent Trends and Applications of Nanoencapsulated Bacteriocins against Microbes in Food Quality and Safety

MDPI

Abstract

Bacteriocins are ribosomal-synthesized peptides or proteins produced by bacterial strains and can inhibit pathogenic bacteria. Numerous factors influence the potential activity of bacteriocins in food matrices. For example, food additives usage, chemical composition, physical conditions of food, and sensitivity of proteolytic enzymes can constrain the application of bacteriocins as beneficial food preservatives. However, novel bacteriocin nanoencapsulation has appeared as an encouraging solution. In this review, we highlight the bacteriocins produced by Gram-negative bacteria and Gram-positive bacteria including lactic acid bacteria that have shown positive results as potential food preservatives. In addition, this review encompasses the major focus on bacteriocins encapsulation with nanotechnology to enhance the antimicrobial action of bacteriocins. Several strategies can be employed to encapsulate bacteriocins; however, the nanotechnological approach is one of the most effective strategies for avoiding limitations. Nanoparticles such as liposomes, chitosan, protein, and polysaccharides have been discussed to show their importance in the nanoencapsulation method. The nanoparticles are combined with bacteriocins to develop the nano-encapsulated bacteriocins from Gram-negative and Gram-positive bacteria including LAB. In food systems, nanoencapsulation enhances the stability and antimicrobial functionality of active peptides. This nanotechnological application provides a formulation of a broad range of antimicrobial peptides at the industry-scale level. Nano-formulated bacteriocins have been discussed along with examples to show a broader antimicrobial spectrum, increase bacteriocins’ applicability, extend antimicrobial spectrum and enhance stability.

Austrian firm in financial difficulty following a deadly Listeria outbreak

Food Safety News

A company in Austria that was linked to a deadly Listeria outbreak earlier this year is in financial trouble.

AKV, an association to protect creditor rights recognized by Austrian authorities, deals with insolvency cases in courts.

It reported that Käserei Gloggnitz can no longer meet its payment obligations. Insolvency proceedings have been opened by the regional court in Wiener Neustadt. A hearing is planned for early February 2023.

The reasons for the insolvency position are unknown, according to AKV. So the impact of the Listeria monocytogenes incident on the company is unclear.

As part of the proceedings, it will have to be checked whether the dairy producer will be continued and restructured or if existing assets will be inventoried and valued.

Research – The Use of Natural Methods to Control Foodborne Biofilms

MDPI

Abstract

Biofilms are large aggregates of various species of bacteria or other microorganisms tightly attached to surfaces through an intricate extracellular matrix. These complex microbial communities present quite the challenge in the food processing industry, as conditions such as raw meats and diverse food product content in contact with workers, drains, machinery, and ventilation systems, make for prime circumstances for contamination. Adding to the challenge is the highly resistant nature of these biofilm growths and the need to keep in mind that any antimicrobials utilized in these situations risk health implications with human consumption of the products that are being processed in these locations. For that reason, the ideal means of sanitizing areas of foodborne biofilms would be natural means. Herein, we review a series of innovative natural methods of targeting foodborne biofilms, including bacteriocins, bacteriophages, fungi, phytochemicals, plant extracts, essential oils, gaseous and aqueous control, photocatalysis, enzymatic treatments, and ultrasound mechanisms.

Research – Study Confirms that Raw Milk Is Linked to Foodborne Illness

Food Poisoning Bulletin

A new study has confirmed that raw milk is linked to foodborne illness. During the time period of 2013 to 2018, 75 outbreaks that caused 675 illnesses were linked to unpasteurized milk. Of these illnesses, almost half were among children and teenagers aged o to 19 years. Given that the consumption of raw milk is low in this country, with only about 1 to 2% of the adult population buying it, these numbers are shocking. The study points out that almost 80% of those outbreaks occurred in states where the sale of raw milk is allowed.

Sweden reports dozens of Shigella infections linked to travel to Cape Verde

Outbreak News Today

Folkhalsomyndigheten, or Sweden’s Public Health Agency reports 30 cases of shigella infection with a travel connection to Cape Verde have been reported in Sweden since mid-November.

Among Swedish travelers, infections with other intestinal pathogens, for example EHEC, Campylobacter, Cryptosporidium and Giardia, have also been noted. Infection with Shigella in connection with trips to Cape Verde has been a recurring problem. This and the presence of various Shigella species and other intestinal pathogens suggest contamination via food.

Shigella bacteria are found in stool, and infection is spread by eating food or drinking liquids contaminated by an infected person, or when a person touches a contaminated surface or object and then touches their mouth or puts the object into their mouth. People infected with shigellosis typically experience a fever, abdominal cramps and diarrhea which may be bloody.

Onset of shigellosis symptoms usually occurs one to two days after exposure—but may take longer—and lasts around a week. Infected people can remain contagious up to six weeks after symptoms resolve.

Most people with shigellosis recover completely without severe complications. In rare cases Shigella may cause bloodstream infections, seizures, kidney failure or arthritis.

Research – Increasing the Safety and Storage of Pre-Packed Fresh-Cut Fruits and Vegetables by Supercritical CO2 Process

MDPI

Abstract

This work presents a feasibility lab-scale study for a new preservation method to inactivate microorganisms and increase the shelf life of pre-packed fresh-cut products. Experiments were conducted on coriander leaves and fresh-cut carrots and coconut.
The technology used the combination of hydrostatic pressure (<15 MPa), low temperature (≤45 °C), and CO2 modified atmosphere packaging (MAP). The inactivation was achieved for the naturally present microorganisms (total mesophilic bacteria, yeasts and molds, total coliforms) and inoculated E. coli. Yeasts and molds and coliform were under the detection limit in all the treated samples, while mesophiles were strongly reduced, but below the detection limit only in carrots.
Inoculated E. coli strains were completely inactivated (>6.0 log CFU/g) on coconut, while a reduction >4.0 log CFU/g was achieved for carrots and coriander. For all the treated products, the texture was similar to the fresh ones, while a small alteration of colour was detected. Microbiological stability was achieved for up to 14 days for both fresh-cut carrots and coconut.
Overall, the results are promising for the development of a new mild and innovative food preservation technique for fresh food.

Research – Spraying an army of bacteria-eating viruses can save us from food poisoning

Interesting Engineering

Every year more than 40 million people in the U.S. suffer from foodborne illnesses caused by bacteria, viruses, and various other types of pathogens. Food contamination is often underestimated, but it is responsible for 420,000 deaths annually. This number represents more people than the entire population of Iceland.

After being produced on a farm, food passes through a lot of channels before it makes it to our platter. Preventing it from contamination is almost impossible. However, a team of researchers from McMaster University in Ontario has figured out a way to free food from disease-causing bacteria before it goes into your stomach, according to a press release.

They have developed a food decontamination spray that employs food-safe microscopic beads containing bacteriophages (viruses that kill bacteria). The researchers claim, during the study, they were able to free lettuce and meat from E. coli 0157, a common food-borne pathogen that infects the human intestine and causes health issues such as diarrhea. 

Research – Evaluation of the Prevalence of Staphylococcus aureus in Chicken Fillets and Its Bio-Control Using Different Seaweed Extracts

MDPI

Abstract

This study aims to assess the occurrence of Staphylococcus aureus in chicken fillets and to control its growth using various lyophilized seaweed extracts (i.e., Halimeda opuntia (HO), Actinotrichia fragilis, and Turbinaria turbinata) by an agar disk diffusion assay in vitro. Results showed that prevalence of S. aureus in breast and thigh samples reached of 92% and 84%, respectively. Lyophilized HO extract was the only seaweed that showed the antibacterial activity against S aureus with a significant difference at p < 0.05. The minimum inhibitory concentration (MIC) of HO extract was 1.5%, with an inhibition zone of 8.16 ± 0.73 mm. Regarding 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, IC50 was recorded at 55.36 μg/mL, whereas cytotoxic IC50 of the lyophilized HO extract on peripheral blood mononuclear cells (PBMCs) was 33.7 µg/mL; a higher IC50 of HO extracts permits their use as a safe food additive in meat products. Moreover, total phenolic compounds and total flavonoids compounds recorded 20.36 ± 0.092 and 16.59 ± 0.029 mg/mL, respectively. HPLC analyses of phenolic compounds profiles exhibited many bioactive substances and the higher ratio was daidzein with 10.84 ± 0.005 µg/mL and followed by gallic acid with a value of 4.06 ± 0.006 µg/mL. In a challenge study, chicken fillet (CHF) experimentally inoculated with S. aureus (ST) and treated with the lyophilized HO algal extract at 4% and 6% (CHF/ST/HO) showed a complete reduction of S. aureus count on the 6th and 4th days in chicken fillet stored at 4 °C, respectively. Moreover, CHF/ST/HO at 4% and 6% of HO extract enhanced the sensory attributes of grilled un-inoculated chicken fillet. Thus, lyophilized HO extracts are promising antibacterial and antioxidant candidates in the chicken meat industry.

Research – Exploring the Diversity of Biofilm Formation by the Food Spoiler Brochothrix thermosphacta

MDPI

Abstract

Brochothrix thermosphacta is considered as a major spoiler of meat and seafood products. This study explores the biofilm formation ability and the biofilm structural diversity of 30 multi-origin B. thermosphacta strains using a set of complementary biofilm assays (biofilm ring test, crystal violet staining, and confocal laser scanning microscopy). Two major groups corresponding to low and high biofilm producers were identified. High biofilm producers presented flat architectures characterized by high surface coverage, high cell biovolume, and high surface area.

Research -Monitoring the incidence and causes of disease potentially transmitted by food in Australia: Annual report of the OzFoodNet network, 2017

Health Au

Abstract

In 2017, 47,652 notifications of enteric diseases potentially related to food were received by state and territory health departments in Australia. Consistent with previous years, the majority of all notified infections were either campylobacteriosis (n = 28,432; 60%) or salmonellosis (n = 16,416; 34%). A total of 206 gastrointestinal outbreaks, including 179 foodborne outbreaks, were reported in 2017. The remaining 27 outbreaks were due to environmental or probable environmental transmission (22 outbreaks), animal-to person or probable animal-to-person transmission (three outbreaks), and waterborne or probable waterborne transmission (two outbreaks). Foodborne outbreaks affected 2,130 people resulting in at least 290 hospital admissions and five deaths. Eggs continue to be a source of Salmonella Typhimurium infection across the country, with 49 egg-related outbreaks affecting at least 746 people reported across six jurisdictions in 2017.