Ultrasonic cleaning to reduce instances of food poisoning

A new study has shown that gentle streams of water carrying sound and microscopic air bubbles can clean bacteria from salad leaves more effectively than current washing methods used by suppliers and consumers. As well as reducing food poisoning, the findings could reduce food waste and have implications for the growing threat of anti-microbial resistance.

Salad and leafy green vegetables may be contaminated with harmful bacteria during growing, harvesting, preparation and retail leading to outbreaks of food poisoning which may be fatal in vulnerable groups.

Because there is no cooking process to reduce the microbial load in fresh salads, washing is vital by the supplier and the consumer.

Washing with soap, detergent bleach or other disinfectants is not recommended and the crevices in the leaf surface means washing with plain water may leave an infectious dose on the leaf. Even if chemicals are used, they may not penetrate the crevices.

In this new study, published in the journal Ultrasound in Medicine and Biology, scientists used acoustic water streams to clean spinach leaves directly sourced from the field crop, then compared the results with leaves rinsed in plain water at the same velocity.

Professor Timothy Leighton of the University of Southampton, who invented the technology and led this research, explains: "Our streams of water carry microscopic bubbles and acoustic waves down to the leaf. There the sound field sets up echoes at the surface of the leaves, and within the leaf crevices, that attract the bubbles towards the leaf and into the crevices. The sound field also causes the walls of the bubbles to ripple very quickly, turning each bubble into a microscopic 'scrubbing' machine. The rippling bubble wall causes strong currents to move in the water around the bubble, and sweep the microbes off the leaf. The bacteria, biofilms, and the bubbles themselves, are then rinsed off the leaf, leaving it clean and free of residues."

The results showed that the microbial load on samples cleaned with the acoustic streams for two minutes was significantly lower six days after cleaning than on those treated without the added sound and bubbles. The acoustic cleaning also caused no further damage to the leaves and demonstrated the potential to extend food shelf life, which has important economic and sustainability implications.

Improving how food providers clean fresh produce could have a major role to play in combating the threat of anti-microbial resistance. In 2018 and 2019, there were fatal outbreaks of different strains of E. coli on romaine lettuce in the USA and Canada and samples from humans infected showed strains that are resistant to antibiotics.

See: Weng Yee Chong, Thomas J. Secker, Craig N. Dolder, Charles W. Keevil, Timothy G. Leighton. The Possibilities of Using Ultrasonically Activated Streams to Reduce the Risk of Foodborne Infection from Salad. Ultrasound in Medicine & Biology, 2021; DOI: 10.1016/j.ultrasmedbio.2021.01.026

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Antimicrobial resistance bacteria found in raw pet food

The fight against antimicrobial resistance has a new problem – raw pet food, according to new research. Sales of biologically appropriate raw food, especially for dogs, have risen in recent years.

Microbiologists working in Switzerland have assessed 51 samples of raw diet pet food, drawn from different suppliers in stores as well as from the Internet. The analysis revealed that some three-quarters of the food samples contained bacteria that has the potential to trigger gastrointestinal infections limits.

Furthermore, over half of the foods that tested were found to contai bacteria that are resistant to antimicrobials, meaning that such organisms are hard to kill. Among the bacteria were certain strains of Escherichia coli. Some bacteria can produce the enzyme extended-spectrum beta-lactamase (EBSL), which can enable these microorganisms to resist the impacts of antibiotics.

Other pathogens that have been isolated from raw pet food includes Campylobacter spp, Clostridium spp, enterotoxigenic Staphylococcus aureus, Listeria monocytogenes, and Salmonella spp.

According to lead researcher Dr. Magdalena Nuesch-Inderbinen: “It is really worrying that we found EBSL-producing bacteria in over 60 percent of samples.”

The new research highlights a new area of concern in the battle against antimicrobial resistance. Antimicrobial resistance is a phenomenon the occurs naturally as bacteria respond to various pressures within the environment. What is of concern is the worldwide acceleration of resistance. U.S. Centers for Disease Control and Prevention (CDC) data finds that many high-income countries are entering a “post antibiotic era.”

One reason for the trend is linked to the practice of animal feed-additive antibiotic usage, which is some countries is an integral part of animal-production technology. The reason for adding of antibiotics is for the creation of 'leaner' meat (animals given antimicrobial tend to grow more quickly). In addition, the indiscriminate administering of antibmicrobials to animals is a way of side-stepping putting in place better animal hygiene conditions.  Many countries have banned this practice, but it also continues in many other parts of the world.

The study additionally highlights concerns for pet owners when considering to buy raw food and then how that food is handled in the home.  In fact, the American Veterinary Animal association “discourages the feeding to cats and dogs of any animal-source protein that has not first been subjected to a process to eliminate pathogens because of the risk of illness to cats and dogs as well as humans.”

The research findings have been reported in the journal Royal Society Open Science.

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

The Patient Safety Atlas

In March of 2016, in an effort to prevent healthcare associated infections (HAIs), the Centers for Disease and Prevention (CDC) issued a request for all healthcare providers and healthcare facilities to make three critical efforts to further this cause. The CDC also launched the online Patient Safety Atlas in an effort to control the rising threat of resistant bacterial infections.

The following guidelines are succinct and offer very clear advice:

1) Prevent infections related to surgery or placement of a catheter.

2) Prevent spread of bacteria from spreading between patients.

3) Improve antibiotic use.

There are six antibiotic resistant bacteria that are particularly dangerous and are considered urgent or serious threats by the CDC. They are:

• MRSA (methicillin-resistant Staphylococcus aureus)
• CRE (carbapenem-resistant Enterobacteriaceae)
• ESBL-producing Enterobacteriaceae (extended-spectrum ß-lactamases)
• VRE (vancomycin-resistant enterococci)
• Multi-drug resistant Pseudomonas
• Multi-drug resistant Acinetobacter

Infections caused by these organisms could lead to sepsis or even death. C. difficile infections are the most common HAI found in hospitals, and in many cases, lead to death. However, it is not antibiotic resistant like the others listed above.

Surgery and Catheters: The recommendation for preventing infections from catheters and after surgery include using catheters only when needed, following recommendations for safer surgery and catheter insertion and care, and removing catheters from patients as soon as they are no longer needed.

Patient Isolation: For preventing C.diffficile, it is recommended that healthcare providers are consistent and follow these actions for every patient without exception. When it is appropriate, patients should be isolated, and providers should know antibiotic resistance patterns in their facility and area.  In order to prevent dangerous bacteria from spreading, it is recommended that hand hygiene be improved and that gloves, gowns, and dedicated equipment be used for patients who have antibiotic resistant infections.

Antibiotic Use: Finally, to improve antibiotic use, it is recommended that cultures be obtained and antibiotics started promptly and reassessed 24 to 48 hours later, especially in cases of sepsis. Cultures should be used to reassess the need for antibiotics and to stop treatment as soon as they are no longer needed. Antibiotics should be used appropriately according to the type of infection and in the proper dosage, frequency, and duration.

The Patient Safety Atlas: A patient safety atlas (PSA) was created by the CDC and is a public portal that allows heathcare providers and the greater public to visualize and download data that is based on four years of surveillance (2011-2014) by 4,403 healthcare facilities. These include general acute care hospitals (n=3,676), long term acute care hospitals (n=506), and free-standing inpatient rehabilitation hospitals (n=221).

Source: Hardy Diagnostics



Posted by Dr. Tim Sandle

Standard to validate microorganism testing methods (food)

ISO 16140:2003 for the validation of alternative (proprietary) microbiological methods has just been revised. The new multipart standard provides a specific protocol and guidelines for the validation of methods both proprietary (commercial) or not. Proprietary methods are generally cheaper to use, produce results faster than traditional culturing methods and are simpler to perform as they require fewer technical skills. What’s more, most are partly or completely automated, so easier to use in less experienced laboratories, such as factory and commercial laboratories and with less technical human resources.

News from ISO:

Two parts of ISO 16140 series now published

ISO 16140-1:2016, Microbiology of the food chain – Method validation – Part 1: Vocabulary, describes the terminology used in microbial testing, while ISO 16140-2:2016, Microbiology of the food chain – Method validation – Part 2: Protocol for the validation of alternative (proprietary) methods against a reference method, is dedicated to the validation of proprietary microbiological methods. They are designed to help food and feed testing laboratories, test kit manufacturers, competent authorities, and food and feed business operators to implement microbiological methods. ISO 16140-2 includes two phases, the method comparison study and the interlaboratory study, with separate protocols for the validation of qualitative and quantitative microbiological methods.

Over a hundred alternative methods have been validated based on the previous version of ISO 16140, and the standard was updated to provide new insights on the validation of microbiological methods and experience gained from conducting validation studies across the world. Today, many alternative (mostly proprietary) methods exist that are used to assess the microbiological quality of raw materials and finished food products and monitor the microbiological status of manufacturing processes. The developers, end-users and authorities need a reliable common protocol for the validation of such alternative methods. With this new protocol, the data generated will also provide potential end-users with performance data for a given method, thus enabling them to make an informed choice on the adoption of a particular (alternative) method. This data can also serve as a basis for the certification of a method by an independent organization.

 “The validation according to ISO 16140-2 will lead to a higher reliability of the alternative method test result and the users will benefit from having microbiological test results available sooner. Most likely, this will contribute to greater food safety,” explained Paul in ‘t Veld, the Convenor of Working Group 3 on method validation (ISO/TC 34/SC 9/WG 3 whose secretariat is held by NEN, ISO member for the Netherlands) that is responsible for the development of the ISO 16140 series.

Posted by Dr. Tim Sandle

ISO 22000 on food safety management

News from ISO:

The consequences of unsafe food can be devastating, both for consumers and businesses worldwide. With many of today’s food products repeatedly travelling across national boundaries, ISO 22000 is more essential than ever to the safety of the global food supply chain. Now the standard is being substantially revised to ensure it stays relevant to modern needs.

 

After a decade of good service, ISO 22000, the International Standard for food management systems, is undergoing a complete modification to bring it up to date with today’s new food safety requirements.

Posted by Dr. Tim Sandle

New ISO Standard for Validating Alternative Food Microbiology Methods

ISO 16140 for the validation of alternative (proprietary) microbiological methods has just been revised. The new multipart standard provides a specific protocol and guidelines for the validation of methods both proprietary (commercial) or not.

Two parts of ISO 16140 series now published:

ISO 16140-1:2016, Microbiology of the food chain - Method validation - Part 1: Vocabulary, describes the terminology used in microbial testing, while ISO 16140-2:2016, Microbiology of the food chain - Method validation - Part 2: Protocol for the validation of alternative (proprietary) methods against a reference method, is dedicated to the validation of proprietary microbiological methods. They are designed to help food and feed testing laboratories, test kit manufacturers, competent authorities, and food and feed business operators to implement microbiological methods. ISO 16140-2 includes two phases, the method comparison study and the interlaboratory study, with separate protocols for the validation of qualitative and quantitative microbiological methods.

For further details, see: ISO

Posted by Dr. Tim Sandle

European food microbiology legislation scheme

The European food microbiology legislation scheme is designed for laboratories that examine foods for compliance with Regulation (EC) 2073/2005 and subsequent amendments.  It has recently been updated.

The European food microbiology legislation scheme assesses the participants’ ability to:

Test and interpret laboratory results in accordance with EU food safety

Process hygiene criteria

The samples are simulated foods to be tested for compliance with either the food safety or the process hygiene criteria.

A list of the updates can be found at the Public Health England site here.

Posted by Dr. Tim Sandle

Foodborne illness in humans

An outbreak is an incident in which two or more people, thought to have a common exposure, experience a similar illness or proven infection (at least one of them having been ill).

A general outbreak is an outbreak affecting members of more than one household or residents of an institution.

In relation to the U.K., Public Health England have a compilation of interesting statistics. The various reports can be found here.

 Posted by Dr. Tim Sandle

Sugar in leafy greens may help gut bacteria

The sugar is called sulfoquinovose (SQ) and is made in green leaves by photosynthesis - the process by which plants use energy from the sun to make chemical energy in the form of sugars. Bacteria use SQ as a source of carbon and sulfur.

Sulfur is important for building proteins - the essential building blocks of all living organisms - explain the authors, who point out that SQ is the only sugar molecule that contains sulfur.

The team thinks it may be possible to use enzymes like YihQ to deliver highly specific antibiotics that target harmful forms of E. coli and other bacteria, such as the food-poisoning bacteria Salmonella, while leaving the good bacteria alone.

When bacteria break down SQ from plants, they release sulfur into the environment, where it re-enters the global sulfur cycle and is used again by the other organisms.

For further details, see: medical news

Posted by Dr. Tim Sandle

Food Safety Consortium to Tackle Foodborne Illness

Bio-Rad Laboratories Inc., a life science research and clinical diagnostic products manufacturer has joined IBM Research and Mars Inc. in the Consortium for Sequencing the Food Supply Chain.  The consortium is harnessing the power of genomics and informatics to study microbiomes in food to help prevent contamination and foodborne illness at any step in the food supply chain.

The consortium was initially launched by IBM and Mars in January of 2015, and since joining the effort, Bio-Rad will contribute expertise in chromogenic and molecular tests for food pathogens and food quality indicators.

Further details on this initiative are discussed on the Bioscience Technology website.

Posted by Dr. Tim Sandle

Food Safety in Manufacturing

New FDA Rules Focus on Food Safety in Manufacturing: Food manufacturers are facing an update to equipment and facility designs to comply with the newest U.S. Food & Drug Administration’s (FDA) safety rules, which focus on the prevention of foodborne illness.

In reaction to a string of recent outbreaks of listeria and salmonella, the FDA announced it has finalized the first two of seven major rules under the Food Safety Modernization Act (FSMA), which focus on implementing modern food manufacturing processes for both human and animal foods that are produced domestically or are imported. Food manufacturers are facing an update to equipment and facility designs to comply with the newest U.S. Food & Drug Administration’s (FDA) safety rules, which focus on the prevention of foodborne illness. In reaction to a string of recent outbreaks of listeria and salmonella, the FDA announced it has finalized the first two of seven major rules under the Food Safety Modernization Act (FSMA), which focus on implementing modern food manufacturing processes for both human and animal foods that are produced domestically or are imported.



 Posted by Tim Sandle

Microbial ecology of fermented foods

Microbiologists Rachel Dutton of Harvard and Benjamin Wolfe of Tufts are studying fermented foods to understand the formation and maintenance of microbial communities. “Fermented foods can be valuable models for processes in less tractable microbiota,” Dutton and Wolfe wrote in a Cell review published recently.

The review is titled "Fermented Foods as Experimentally Tractable Microbial Ecosystems."

The abstract reads:

"Microbial communities of fermented foods have provided humans with tools for preservation and flavor development for thousands of years. These simple, reproducible, accessible, culturable, and easy-to-manipulate systems also provide opportunities for dissecting the mechanisms of microbial community formation. Fermented foods can be valuable models for processes in less tractable microbiota."

Posted by Tim Sandle

Changing the Phase of Salmonella

The majority of serotypes of Salmonella possess two phases of H (flagellar) antigens. If agglutination is obtained with one phase, the organism may be induced to change to the other phase.

Most isolates exist in two phases: phase 1, phase 2 or may have both phases simultaneously. Cultures that are not expressed in one phase upon primary culture may be switched to the other phase using 2 methods: a Craigie’s tube or ditch plate (Jamieson’s plate1-3). Both methods involve adding the test organism to the H anti-serum which it has already agglutinated with. Organisms in the original phase demonstrated, agglutinate with the H anti-serum, leaving the organisms in the alternative phase free to move in the culture.

To understand more about this, please refer to a technical report from Public health England here.

Posted by Tim Sandle

IFSAC Report on Key Sources of Foodborne Illness

The Interagency Food Safety Analytics Collaboration (IFSAC) is a partnership of three agencies - the CDC, FDA and FSIS who have together developed an improved method for analyzing outbreak data to determine which foods are responsible for illnesses related to four major foodborne bacteria.

The IFSAC project has published its findings in a new report “Foodborne Illness Source Attribution Estimates for Salmonella, Escherichia coli O157, Listeria monocytogenes, and Campylobacter using Outbreak Surveillance Data,” (published February 2015).

The report briefly summarizes IFSAC’s methods and results, including estimated attribution percentages for the four pathogens named in its title. CDC estimates that, together, these four pathogens cause 1.9 million cases of foodborne illness in the United States each year.

Analysing data from nearly 1,000 outbreaks that occurred from 1998 to 2012 to assess which categories of foods were most responsible for making people sick with Salmonella, Escherichia coli O157, Listeria monocytogenes, and Campylobacter. IFSAC experts divided food into 17 categories for the analysis. The pathogens were chosen because of the frequency or severity of the illnesses they cause, and because targeted interventions can have a significant impact in reducing them.

The report presents the methods behind the results and provides details about the amount of uncertainty around the estimates. Some of the findings include:

• More than 80% of E. coli O157 illnesses were attributed to beef and vegetable row crops, such as leafy vegetables.
• Salmonella illnesses were broadly attributed across food commodities, with 77% of illnesses related to seeded vegetables (such as tomatoes), eggs, fruits, chicken, beef, sprouts and pork.
• Nearly 75% of Campylobacter illnesses were attributed to dairy (66%) and chicken (8%). Most of the dairy outbreaks used in the analysis were related to raw milk or cheese produced from raw milk, such as unpasteurized queso fresco.
• More than 80% of Listeria illnesses were attributed to fruit (50%) and dairy (31%). Data were sparse for Listeria, and the estimate for fruit reflects the impact of a single large outbreak linked to cantaloupes in 2011.
• Due to limitations in outbreak data and uncertainty in the estimates, IFSAC recommends caution in interpreting certain findings, such as the estimates for Campylobacter in dairy and Listeria in fruits. IFSAC suggests that the results be used with other scientific data for risk-based decision making.

Read the report here.

Posted by Tim Sandle

Multi-Drug Resistance in Food Pathogens

Treatment options for some of the most common food-borne infections are decreasing, as isolates continue to show resistance to antimicrobial drugs. For example, multi-drug resistant isolates of Salmonella continue to spread across Europe. Also, high resistance to ciprofloxacin in Campylobacter isolates in both humans and animals has been reported in some Member States.  Encouragingly, co-resistance to critically important antimicrobials for both bacteria remains low. These are some the findings of the latest EFSA-ECDC European Union Summary Report on antimicrobial resistance (AMR) in zoonotic and  indicator bacteria from humans, animals and food, which analyses data from 2013.

For the first time, EFSA and ECDC have used similar criteria to interpret data. “Findings in antimicrobial resistance in humans, animals and foods are now more comparable. This is a step forward in the fight against antimicrobial resistance”, said Marta Hugas, Acting Head of EFSA’s Risk Assessment and Scientific Assistance Department.

“The high levels of resistance to fluoroquinolones observed in Campylobacter isolates from both humans and broilers are of concern considering that a large proportion of human Campylobacter infections come from handling, preparation and consumption of broiler meat. Such high resistance levels reduce the effective treatment options for severe human Campylobacter infections”, said Mike Catchpole, Chief Scientist at ECDC.

Key findings

1. Resistance in Salmonella to commonly used antimicrobials was frequently detected in humans and animals (especially broilers and turkeys) and derived meat products. Multi-drug resistance was high (in humans 31.8%, in broilers 56.0%, in turkey 73.0%, and in fattening  pigs 37.9%), and the  continued spread of particularly multi-drug resistant clones reported in both human and animal (broilers, pigs and cattle) isolates is of concern.
2. Resistance to commonly used antimicrobials in Campylobacter isolates was frequently detected in humans and animals (especially broilers, pigs and cattle). In food, resistance was detected in broiler meat. Resistance to ciprofloxacin, a critically important antimicrobial, was particularly high in humans (meaning that treatment options for serious infections with these zoonotic bacteria are reduced). In Campylobacter jejuni more than half of both human and broiler isolates (54.6% and 54.5% respectively) were resistant, alongside 35.8% in cattle. In E. coli two thirds of humans and broiler isolates (66.6% and 68.8% respectively) were resistant along with 31.1% of pig isolates.
3. Levels of co-resistance to critically important antimicrobials in Salmonella were low (in humans 0.2%, in broilers 0.3%, and in fattening pigs and in turkey there was none). Levels of multi-drug resistance and co-resistance in Campylobacter isolates to critically important antimicrobials were generally reported at low to moderate levels in animals (in C. jejuni isolates from broilers and cattle 0.5% and 1.1%, respectively, in C. coli isolates from broilers and fattening pigs 12.3% and 19.5%, respectively) and at low levels in humans (1.7% in E. jejuni and 4.1% in E. coli).
4. The report also includes data on resistance in indicator Escherichia coli,indicator enterococci and  methicillin-resistant Staphylococcus aureus, in animals and food.

Read full report here - EU Summary Report on antimicrobial resistance in zoonotic and indicator bacteria from humans, animals and food in 2013

Posted by Tim Sandle

GMPs for food products: disinfection

A new paper of interest by Sofija Petkovska1 and Biljana Gjorgjeska, in relation to food hygiene control, published in Journal of Hygienic Engineering and Design.

The abstract reads:

The usage of different disinfectants in the food and pharmaceutical industry provides a possibility for application of certain level of assurance related to microbiological cleanness by using different types of disinfectants which have different spectrum of operation. Used disinfectants residues which stay on the critical points of the equipment after cleaning become potential contaminants of the products and they can be unsafe for the users’ health. Because of this reasons, the Good Manufacture Practice standards recommend validation of the production equipment cleaning procedures including the aspects of microbiological cleanness
and determination of residues of disinfectants.

According to the Republic of Macedonia regulation acts, an application of HACCP system is recommended which will provide safe food with good quality. The methods and control points described in the general principles of this standard are internationally recognized and are from essential meaning. We would recommend in the control of the residues of disinfectants the general principles of HACCP to be used together with the principles of Good Manufacture Practice (GMP) which is well known standard recommended for pharmaceutical production. The validation plan should include determination of the residue quantity of the disinfectant after cleaning with the disinfectant used. The control method for determination of the residue quantity depends on the chemical characteristics of the disinfectant used. In general, specific methods that are sensitive and give possibility for the detection and quantification of selected disinfectant should be used.

Foe details, see food micro.

Posted by Tim Sandle

PCR for food microbiology

Real-time PCR assays for food microbiology have been developed into commercial products whereby some or all of the steps can be automated to minimise the number of operations involved and reduce the risk of contamination. Automation requires a higher capital investment and so will depend on the sample throughput required. The reaction usually takes place inside a computer-controlled combined thermocycler/fluorescence detection instrument and uses pre-prepared reagents. For foodborne pathogen detection tests, the entire process can be completed within 20-30 hours with sufficient sensitivity to detect a single cell in a 25g sample.

The main advantage for PCR-based methods is in shorter detection times, but the high degree of automation built into PCR systems also allows relatively unskilled staff to run them without extensive training. The high specificity of PCR can also mean fewer repeat tests. The principal disadvantage is currently cost, both in terms of capital outlay and consumables. While larger laboratories can benefit from reduced labour costs, economies of scale and rapid results, the benefits for smaller labs may be less clear.

A number of commercial PCR systems are currently offered for food pathogen detection. One of the first into the marketplace was the Bax® system from Dupont Qualicon and this has been joined by TaqMan® and MicroSEQ® food pathogen detection kits from Life Technologies, iQ Check real-time PCR kits from Bio-Rad, foodproof® real-time PCR detection kits distributed by Merck, and several others.

One of the main reasons for the comparatively high capital cost of PCR-based detection systems is the need for thermocycling during the amplification step. Instruments must be capable of very accurate and precise temperature control throughout the cycle. In addition to the capital investment for the instrumentation, the chemistry is also expensive as it uses fluorescent probes. Novel developments in DNA synthesis have demonstrated alternative solutions for DNA amplification under isothermal conditions without the need for a thermocycler. There are several types of nucleic acid amplification technologies. Amongst the isothermal DNA amplification technologies that have been developed, loop-mediated isothermal amplification (LAMP) has been used widely to detect microorganisms and is a promising and suitable technology for the rapid detection of pathogen in the field. LAMP uses multiple primers and a bacterial polymerase, Bst polymerase, derived from Bacillus stereothermophilus to amplify DNA rapidly at a constant 63oC. This does away with the need for a thermocycler component in the instrument and can reduce the cost by up to two thirds.

A commercial isothermal amplification system has already been developed for food pathogen detection. The 3M™ Molecular Detection System uses a unique bioluminescence method to detect the amplification of DNA sequences and is designed to be simple to use. The amplification and detection processes are completed within 75 minutes with real-time positive results available as early as 15 minutes. An overnight single enrichment step is still required at present. Test kits for E. coli O157 including H7, Salmonella and Listeria spp. detection in food and environmental samples are currently available.

Portable PCR-based instruments have also been developed recently. For example, Idaho Technology markets the ‘Ruggedized Advanced Pathogen Identification Device’ or R.A.P.I.D.® System, which uses an air thermocycling process and a fluorimetric detection system to detect Salmonella, Listeria, E. coli O157 and Campylobacter in food samples.
Posted by Rapid Microbiology

Salmonella enteritidis outbreak linked to eggs

Public Health England is continuing to investigate a national outbreak of Salmonella enteritidis. Total reported numbers have reached 247 cases, from 158 on 15 August 2014. The additional cases are not new infections from the last 7 days, but historical cases reported to PHE during that week. Encouragingly, overall case reporting slowed over the last week.

Dr Paul Cleary, consultant epidemiologist at PHE, said: “Investigations into the recent Salmonella enteritidis outbreak are progressing, at both a national and European level. There is now evidence to indicate that cases in Europe with the same strains of Salmonella infection were associated with consumption of eggs from a single source. This egg supply also reached distributors and food outlets in England, but at this stage we cannot conclusively demonstrate this is the infection source in this country.

“We are continuing to work with the Food Standards Agency and public health organisations in Europe but, importantly, the decline in Salmonella case reporting this week alongside other elements of our investigations reassures us that the current risk to public health is low.”

Posted by Tim Sandle

Enterobacteriaceae, Coliforms, and Escherichia Coli

The Enterobacteriaceae is a large family of Gram-negative bacteria that includes, along with many harmless symbionts, many of the more familiar pathogens, such as Salmonella, Escherichia coli, Yersinia pestis, Klebsiella, Shigella, Proteus, Enterobacter, Serratia, and Citrobacter. Members of the Enterobacteriaceae are rod shaped and typically are 1–5 mm in length. Enterobacteria have Gram-negative stains, and they are facultative anaerobes, fermenting sugars to produce lactic acid and various other end products. Many members of this family are a normal part of the gut flora found in the intestines of humans and other animals, whereas others are found in water or soil, or are parasites on a variety of different animals and plants.

This is the introduction to a chapter by Tim Sandle for the new edition of the Encyclopedia of Food Microbiology. The reference is:

Sandle, T., 2014. Biochemical and Modern Identification Techniques: Enterobacteriaceae, Coliforms, and Escherichia Coli. In: Batt, C.A., Tortorello, M.L. (Eds.), Encyclopedia of Food Microbiology, 2^nd edition, vol 1. Elsevier Ltd, Academic Press, pp. 232–237

Written by the world's leading scientists and spanning over 400 articles in three volumes, the Encyclopedia of Food Microbiology, Second Edition is a complete, highly structured guide to current knowledge in the field. Fully revised and updated, this encyclopedia reflects the key advances in the field since the first edition was published in 1999

The articles in this key work, heavily illustrated and fully revised since the first edition in 1999, highlight advances in areas such as genomics and food safety to bring users up-to-date on microorganisms in foods. Topics such as DNA sequencing and E. coli are particularly well covered.

With lists of further reading to help users explore topics in depth, this resource will enrich scientists at every level in academia and industry, providing fundamental information as well as explaining state-of-the-art scientific discoveries.

For details see: Encyclopedia of Food Microbiology

To review a copy, please contact Tim Sandle.

Posted by Tim Sandle

Classification of the Peronosporomycetes

Physiologically and morphologically, as obligately osmotrophic heterotrophs, the Peronosporomycetes are ‘fungi.’ They are phylogenetically separate from the Mycota (an alternative taxonomic name for the kingdom Fungi) and sometimes are described as Oomycota. The biflagellate, anisokont but nonstraminipilous Plasmodiophorales and the uniflagellate Chytridiomycetes likewise are unrelated. The Chytridiomycetes may be an early offshoot from the phylogenetic line leading tothe nonflagellate Mycota.

The Peronosporomycetes are algae fungi or cellulose fungi, form a class within the Stramenopilen, and therefore are much closer to brown algae, golden algae, and diatoms used as the genuine fungi. The taxa include several plant pathogens, such as the causative agent of late blight of potato and downy mildews.

The Peronosporomycetes include the most numerous, most important, and earliest known (with mid-eighteenth century reports for Saprolegnia on fish) water molds…

In relation to this, Tim Sandle has written an article for the new edition of the Encyclopedia of Food Microbiology. The reference is:

Sandle, T., 2014. Fungi: Classification of the Peronosporomycetes. In: Batt, C.A., Tortorello, M.L. (Eds.), Encyclopedia of Food Microbiology, vol 2. Elsevier Ltd, Academic Press, pp. 44–53

For more details about the Encyclopedia of Food Microbiology, please see: EFC

Posted by Tim Sandle