Leading the way in rapid detection technology

It is not just academia that can spawn successful spin-outs – here we find out how to go from defence technology to food science in one easy step

New technology could give faster ways to detect food pathogens such as E.coli

Based at Porton Down, near Salisbury, Tetricus provides specialist support to bioscience start-ups and access to the world-class expertise of the Defence Science and Technology Laboratories (Dstl) and the Health Protection Agency (HPA).

Tetricus is working closely with Ploughshare Innovations - a wholly owned subsidiary of Dstl - which was set up to commercialise defence technologies in non-defence markets. With over 150 patented technologies available at any one time for exploitation, Ploughshare has become a rich source of commercially attractive intellectual property. 

Ploughshare has spun out a number of companies to develop commercial applications of the rapid detection technologies first used to counter the threat of biological warfare in the first Gulf war.

Three of these companies are based at Tetricus - Alaska Food Diagnostics, Acolyte Biomedica and Enigma Diagnostics – where they have developed specialist microbiological testing technologies that offer important timesaving benefits to users.

Alaska Food Diagnostics - a unique joint venture between Ploughshare Innovations and private investors - is helping to revolutionise food safety in the UK and international markets with its rapid microbiology tests. Alaska’s team of world-class scientists has exploited patented Adenylate Kinase (AK) Phage technology to develop a highly sensitive and specific series of rapid assays addressing food safety and product quality issues.

The fastrAK system shares the proven core technology of the clinical microbial detection platform recently acquired by a high profile blue chip multinational. Having built an experienced management, development and technical team, the company is now using its knowledge and exclusive global licence to bring AK technology to the food and beverage market.
 
The assay comprises two levels of specificity:
o immuno-magnetic bead separation (IMS) to capture the food pathogen of interest from pre-enrichment broths, and
o bacteriophage lysis to release intracellular AK from the target cells in a highly specific manner.

A powerful amplification step uses the AK released to mediate the conversion of ADP to ATP and is measured as visible light produced by the bioluminescent reaction of the recombinant firefly enzyme, luciferase.

The fastrAK luminometer read-out then provides an extremely sensitive bioluminescent end-point compared with standard ATP assays. With methodology simple to employ in the laboratory, the assay’s total ‘hands on’ time is less than 15 minutes.

Primary validation studies demonstrated that the initial manual assay could detect a single colony-forming unit (CFU) of the food pathogens Salmonella, E. Coli and Listeria in a single matrix (skimmed milk) in less than eight hours - a unique finding in the food testing market.

Following evaluation at the internationally acclaimed and independent accreditation organisation Campden and Chorleywood Food Research Association (CCFRA) for the same assay for Salmonella, Director of Microbiology, Dr Roy Betts concluded: “In our tests Alaska’s fastrAK method produced higher numbers of positive results within a working day, compared to conventional methods which required over five days for a confirmed positive result. This is a dramatic improvement in accuracy and speed.”

As well as thorough testing and validation by leading reference centres, the combination of this novel rapid technology with established culture and immuno-magnetic methods also provides reassurance to food testing laboratories resistant to embrace unfamiliar molecular techniques.

Alaska has just brought its first product to market - fastrAK Salmonella for processed poultry products. In customer trials with cooked chicken and ready to eat (RTE) products, the semi-automated assay yielded results within 18 hours, compared with a conventional culture method requiring three days for a confirmed negative result and over five days for confirmed positive result. fastrAK provided next morning results with over 95% sensitivity and 98% specificity, saving a whole operating day over automated immunoassay methods.

Much headway has been made in the rapid testing market with the more recent molecular and immunoassay-based methods (PCR and ELISA respectively) bringing the Time To Result (TTR) down to 24-36 hours, compared with up to a week using traditional culture-based methods. The 100-fold amplification process of Alaska’s AK Phage technology is key to the high degree of sensitivity of the assay and therefore the fastest TTR of 18 hours.

New EU microbiological criteria regulations applying to food of animal origin came into force from 1 January 2006. These microbiological criteria are aimed at food business operators in the context of their good hygiene practice and Hazard Analysis Critical Control Point (HACCP) procedures.

For the meat industry, they include carcass-testing requirements replacing those of the Meat (HACCP) Regulations 2002, including new criteria for Salmonella in red meat and poultry carcases. For slaughterhouses the regulations set out process hygiene criteria that should be used to ensure the production processes are operating properly and includes Salmonella testing of broiler and turkey carcasses. Even further upstream in the process, testing on farms can influence HACCP decisions to progress along ‘cutting’ versus ‘cooking’ production lines.

Providing food manufacturers with results in just 18 hours from sample receipt, fastrAK brings a unique offering to the food testing market. Fast and accurate pathogen detection is particularly important during production and Quality Control (QC) testing of final product.

At this stage, sample pre-enrichment for 16 hours can be initiated throughout the day, ready for testing the next morning. After just two hours, products with known QC results can be positively released and shipped in time to meet the rigorous shelf life requirements of the processed poultry market.

The availability of results 6 hours earlier than with comparable methods effectively creates a working day advantage, even compared to the fastest competitive technologies, leading to cost savings on product storage and supply chain logistics. This allows both food manufacturers and retailers to offer greater security and quality assurance to the ‘farm to fork’ supply chain.

Signifying a major step forward in the rapid detection of food pathogens, "The time to result for this assay is a real breakthrough, together with its accuracy, and we are confident it will make a significant impact in the drive for improved food safety standards”, explained Alaska’s head of Microbiology Research and Development, Dr Pradip Patel.

CEO Laurence Callow added: “Alaska is here primarily to assist the food industry to reduce its cost base and to meet the increasing consumer and regulatory demands on its operations. This science delivers savings to the food industry from the first day of application and has its roots in one of the finest scientific research establishments in the world. Independent confirmation of the speed and accuracy of its detection methods has greatly increased interest in the technology and it is likely that within the next two years, its cost benefits will make it the testing technology of choice for leading food producers. The total global savings to the food industry could run into billions of dollars.”

Similarly, Acolyte Biomedica uses the specialised laboratories at Tetricus to develop rapid screening tests for antibiotic-resistant hospital infections.  Such has been the success of Acolyte Biomedica that the company has recently been acquired by the large multinational 3M. 

Meanwhile, Enigma Diagnostics has developed a portable device for the rapid, in-field genetic analysis or detection of micro-organisms or genetic material, taking analysis out of the traditional laboratory environment. All three companies have benefited from close collaboration with the originators of the technology and access to the world-class knowledge network provided by Tetricus.

“Tetricus has become a centre of expertise in rapid microbiological detection technologies for biomedical, veterinary, environmental and food applications”, said Dr Clive Duggleby, general manager of Tetricus. 

“As well as providing tenant companies with the professional support and infrastructure they need to realise their commercial ambitions, we offer access to a world-class knowledge network that includes some of the nation’s most talented scientists thanks to our strong links with the Dstl and the Health Protection Agency”, he added.

Tetricus is a joint venture between Dstl, New Sarum Enterprises (which provides access to a network of specialist business support providers), and Great Western Enterprise (a not-for-profit business support group that works with small and medium-sized businesses to help create and sustain economic growth).

In addition to providing firms with access to an unrivalled knowledge network, it also provides specialist premises and business support for bioscience companies.

By Dr Clive Duggleby. He is General Manager of the Tetricus Bioincubator. Before this Clive worked for 15 years at the PHLS Centre for Applied Microbiology & Research (CAMR), utilising recombinant DNA technology to yield products of commercial, medical, defence or academic importance.