Join 8,361 other subscribers
- 307,915 Views
Category Archives: Bacteriophage
Research – A Highly Effective Bacteriophage-1252 to Control Multiple Serovars of Salmonella enterica
Salmonella enterica (S. enterica) is the most common foodborne pathogen worldwide, leading to massive economic loss and a significant burden on the healthcare system. The primary source of S. enterica remains contaminated or undercooked poultry products. Considering the number of foodborne illnesses with multiple antibiotic resistant S. enterica, new controlling approaches are necessary. Bacteriophage (phage) therapies have emerged as a promising alternative to controlling bacterial pathogens. However, the limitation on the lysis ability of most phages is their species-specificity to the bacterium. S. enterica has various serovars, and several major serovars are involved in gastrointestinal diseases in the USA. In this study, Salmonella bacteriophage-1252 (phage-1252) was isolated and found to have the highest lytic activity against multiple serovars of S. enterica, including Typhimurium, Enteritidis, Newport, Heidelberg, Kentucky, and Gallinarum. Whole-genome sequencing analysis revealed phage-1252 is a novel phage strain that belongs to the genus Duplodnaviria in the Myoviridae family, and consists of a 244,421 bp dsDNA, with a G + C content of 48.51%. Its plaque diameters are approximately 2.5 mm to 0.5 mm on the agar plate. It inhibited Salmonella Enteritidis growth after 6 h. The growth curve showed that the latent and rise periods were approximately 40 min and 30 min, respectively. The burst size was estimated to be 56 PFU/cell. It can stabilize and maintain original activity between 4 °C and 55 °C for 1 h. These results indicate that phage-1252 is a promising candidate for controlling multiple S. enterica serovars in food production.
Posted in Bacteriophage, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Phage, Salmonella
Research – Natural Killers: Opportunities and Challenges for the Use of Bacteriophages in Microbial Food Safety from the One Health Perspective
Ingestion of food or water contaminated with pathogenic bacteria may cause serious diseases. The One Health approach may help to ensure food safety by anticipating, preventing, detecting, and controlling diseases that spread between animals, humans, and the environment. This concept pays special attention to the increasing spread and dissemination of antibiotic-resistant bacteria, which are considered one of the most important environment-related human and animal health hazards. In this context, the development of innovative, versatile, and effective alternatives to control bacterial infections in order to assure comprehensive food microbial safety is becoming an urgent issue. Bacteriophages (phages), viruses of bacteria, have gained significance in the last years due to the request for new effective antimicrobials for the treatment of bacterial diseases, along with many other applications, including biotechnology and food safety. This manuscript reviews the application of phages in order to prevent food- and water-borne diseases from a One Health perspective. Regarding the necessary decrease in the use of antibiotics, results taken from the literature indicate that phages are also promising tools to help to address this issue. To assist future phage-based real applications, the pending issues and main challenges to be addressed shortly by future studies are also taken into account.
Posted in Bacteriophage, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Safety, Food Safety Management, food safety training, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Phage
Research – UK to tackle Salmonella risks in raw pet food
The UK Food Safety Research Network, hosted by Quadram Institute, announced that six food safety projects will receive between £30,000 to £62,000 (roughly $36,544 USD to $73,089 USD) in funds. One of the projects aims to improve food safety of raw pet food formulas.
All six projects involve academic researchers collaborating with commercial companies and/or government agencies within the human and pet food sectors to establish solutions to common food safety issues.
The raw pet food project involves using bacteriophages to help decrease Salmonella contamination in raw pet food products. According to the Quadram Institute, raw pet foods are growing in popularity throughout the United Kingdom as pet parents seek non-processed diets to improve their pets’ health. However, raw pet foods can carry higher risk of contamination compared to their cooked counterparts.
Research – Cross-Contamination to Surfaces in Consumer Kitchens with MS2 as a Tracer Organism in Ground Turkey Patties
It is estimated that one in five cases of foodborne illnesses is acquired in the home. However, how pathogens move throughout a kitchen environment when consumers are preparing food is not well characterized. The purpose of this study was to determine the prevalence and degree of cross-contamination across a variety of kitchen surfaces during a consumer meal preparation event. Consumers (n = 371) prepared a meal consisting of turkey patties containing the bacteriophage MS2 as a tracer organism and a ready-to-eat lettuce salad. Half were shown a video on proper thermometer use before the trial. After meal preparation, environmental sampling and detection were performed to assess cross-contamination with MS2. For most surfaces, positivity did not exceed 20%, with the exception of spice containers, for which 48% of the samples showed evidence of MS2 cross-contamination. Spice containers also had the highest MS2 concentrations, at a mean exceeding 6 log viral genome equivalent copies per surface. The high level of MS2 on spice containers drove the significant differences between surfaces, suggesting the significance of spice containers as a vehicle for cross-contamination, despite the absence of previous reports to this effect. The thermometer safety intervention did not affect cross-contamination. The efficiency of MS2 transfer, when expressed as a percentage, was relatively low, ranging from an average of 0.002 to 0.07%. Quantitative risk assessment work using these data would aid in further understanding the significance of cross-contamination frequency and efficiency. Overall, these data will help create more targeted consumer messaging to better influence consumer cross-contamination behaviors.
- Forty-eight percent of spice containers sampled showed evidence of MS2 cross-contamination.
- Spice containers had the highest MS2 concentrations across kitchen surfaces.
- Spice containers may be a key vehicle for cross-contamination.
- The thermometer safety intervention did not affect cross-contamination.
- The efficiency of MS2 transfer was relatively low, ranging from 0.002 to 0.07%.
Posted in Bacteriophage, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk
Research – Spraying an army of bacteria-eating viruses can save us from food poisoning
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.
Posted in Bacteriophage, Decontamination Microbial, E.coli O157, E.coli O157:H7, Food Illness, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Foodborne Illness, Illness, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, STEC, STEC E.coli
Research – Antimicrobial Phage Spray Effective Against Foodborne Bacteria, Including Multidrug Resistant E. Coli
Researchers at McMaster University have developed a new, highly effective tool to mitigate bacterial contamination of foods, including pathogens displaying antimicrobial resistance (AMR). The technology involves the application of bacteriophages (phages)—benign viruses that eat bacteria—to goods in the form of microgels.
Phages are natural predators to bacteria, and because phages attack bacteria in a highly targeted manner, they can be used in food and agriculture without disturbing the balance of microbial communities. Phage products have been approved by the US Food and Drug Administration (FDA) for controlling dangerous bacterial contaminants such as Escherichia coli in food products. Though they do not affect the taste, texture, and nutritional quality of foods, phages are not widely used by industry due to challenges with delivery and stability of phage products.
Posted in antimicrobial resistance, Bacteriophage, Decontamination Microbial, E.coli, FDA, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Uncategorized
Research -Application of a novel phage ZPAH7 for controlling multidrug-resistant Aeromonas hydrophila on lettuce and reducing biofilms
Aeromonas hydrophila is an important pathogenic bacterium that causes foodborne illness worldwide. In this study, virulent phages from the sediment of a fish farm were propagated and isolated on a multidrug-resistant strain of A. hydrophila, ZYAH75. One phage, designated as ZPAH7, featured a unique turbid halo around a clear plaque on the bacterial lawn (indicative of potential depolymerase activity), and was selected for further analysis. ZPAH7 was classified as podophage by morphological and genomic methods. Further comparisons of genome nucleotide similarity, ratios of homologous proteins and phylogenetic relatedness among the terminase large subunit and major capsid proteins of similar phage deposited in GENBANK, led us to propose a new genus, ZPAH7virus, in the Autographivirinae subfamily of Podoviridae. ZPAH7 had an adsorption rate of 79% in 5 min, an eclipse period of 15 min, a latent period of 25 min, and a burst size of 148 ± 9 PFU/cell. Antimicrobial application experiments showed that ZPAH7 lead to significantly reduction on A. hydrophila on lettuce. Additionally, ZPAH7 was able to inhibit biofilm formation, as well as degrade and kill bacteria in established biofilms. Furthermore, lytic activity of ZPAH7 remained stable across a wide range of temperatures and pH measurements. These results suggest ZPAH7 could be used as a potential biological control agent against A. hydrophila on food and/or biofilms on food contact surfaces.
Posted in Aeromonas, Bacteriophage, Biofilm, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Research
Research – Bacteriophage cocktail shows promise against Vibrio outbreaks in shrimp farms
Researchers from the Biological Research Center of the Northwest, the Autonomous University of Nuevo León, the Food and Development Research Center AC and the University of Girona evaluated the protective effects of a cocktail of bacteriophages in L. vannamei post larvae against Vibrio bacteria. The scientists found that treating the PLs with bacteriophages kept Vibrio infections at bay and reduced their concentrations in culture water – without harming the surrounding bacterial communities.
Vibrio populations and bacteriophages
Vibrio bacteria are widely disseminated in ocean environments and several Vibrio species are responsible for disease outbreaks in marine animals – especially penaeid shrimp, different fish species and molluscs. Some strains of V. harveyi and V. campbellii have been implicated in disease outbreaks in shrimp hatcheries and grow-out facilities around the world. They’ve also been associated with coral infections.
“We used culture-dependent and culture-independent approaches to explore their effects on bacterial communities associated with shrimp post larvae,” the researchers said. According to the results of the study, administering the phage cocktail drastically reduced Vibrio counts in both in vitro and in vivo environments.
Posted in Bacteriophage, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Research, Vibrio, Water Safety
Research – Efficacy of Repeated Applications of Bacteriophages on Salmonella enterica-Infected Alfalfa Sprouts during Germination
Nontyphoidal Salmonella enterica is one of the leading pathogens for foodborne outbreaks in a multitude of food commodities, including alfalfa sprouts, which are commonly consumed raw. The food industry has commonly used chlorinated washes, but such methods may not be perceived as natural; this can be a detriment as a large portion of sprouts are designated for the organic market. A natural and affordable antimicrobial method that has been acquiring popularity is the use of bacteriophages. This study compared the efficacy of repeated daily applications and a single application of two separate bacteriophage cocktails (SE14, SE20, SF6 and SE14, SF5, SF6) against four Salmonella enterica (S. enterica) strains on germinating alfalfa sprout seeds from days 0 to 7. The results show S. Enteritidis to be the most susceptible to both cocktails with ~2.5 log CFU/mL decrease on day 0 with cocktail SE14, SF5, and SF6. S. enterica populations on all strains continued to grow even with repeated daily bacteriophage applications but in a significantly decreased rate (p < 0.05) compared with a single bacteriophage application. The extent of the reduction was dependent on the S. enterica strain, but the results do show benefits to using repeated bacteriophage applications during sprout germination to reduce S. enterica populations compared with a single bacteriophage application.
Posted in Bacteriophage, food bourne outbreak, food contamination, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, foodborne outbreak, foodbourne outbreak, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, outbreak, Pathogen, pathogenic, Research, Salmonella
Research – Inhibition of Listeria monocytogenes by Phage Lytic Enzymes Displayed on Tailored Bionanoparticles
The high mortality rate associated with Listeria monocytogenes and its ability to adapt to the harsh conditions employed in food processing has ensured that this pathogen remains a serious problem in the ready-to-eat food sector. Bacteriophage-derived enzymes can be applied as biocontrol agents to target specific foodborne pathogens. We investigated the ability of a listeriophage endolysin and derivatives thereof, fused to polyhydroxyalkanoate bionanoparticles (PHA_BNPs), to lyse and inhibit the growth of L. monocytogenes. Turbidity reduction assays confirmed the lysis of L. monocytogenes cells at 37 °C upon addition of the tailored BNPs. The application of BNPs also resulted in the growth inhibition of L. monocytogenes. BNPs displaying only the amidase domain of the phage endolysin were more effective at inhibiting growth under laboratory conditions (37 °C, 3 × 107 CFU/mL) than BNPs displaying the full-length endolysin (89% vs. 83% inhibition). Under conditions that better represent those found in food processing environments (22 °C, 1 × 103 CFU/mL), BNPs displaying the full-length endolysin demonstrated a greater inhibitory effect compared to BNPs displaying only the amidase domain (61% vs. 54% inhibition). Our results demonstrate proof-of-concept that tailored BNPs displaying recombinant listeriophage enzymes are active inhibitors of L. monocytogenes. View Full-Text
Posted in Bacteriophage, Decontamination Microbial, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Technology