In the US alone, there are an estimated 47.8 million illnesses, over 127,000 hospitalizations and 3,000-plus deaths attributed to foodborne illness each year. Traditional means for microbial detection can no longer match the pace of today’s food processing and global distribution networks. Emerging rapid sensor and detection platforms can provide the timely and actionable information needed to lessen the human and economic burdens levied by foodborne disease.

This conference will feature presentations on emerging optical, nanotechnological, spectroscopic and electrochemical technologies for pathogen detection, including label-free and high-throughput methods. Novel ligands for pathogen capture will be examined, along with benefits and challenges of these new methods and a comparison to existing techniques. Label-free approaches and the advantages of novel bioaffinity ligands will also be highlighted.

Final Agenda

Wednesday, June 27, 2018

7:30 am Registration and Morning Coffee

The Fundamentals of Rapid Methods

8:25 Chairperson’s Opening Remarks

Byron Brehm-Stecher, PhD, Associate Professor, Rapid Microbial Detection and Control Laboratory, Iowa State University

8:30 KEYNOTE PRESENTATION: Sampling: The Forgotten Part of Microbiological Testing

Robert L. Buchanan, PhD, Professor, Department of Nutrition and Food Science and Center for Food Safety and Security Systems, University of Maryland

9:00 Rapid Methods - Where They Come from and How They Have Impacted Food Testing

Peter Feng, PhD, Research Microbiologist, Center for Food Safety and Applied Nutrition, US Food and Drug Administration

The FDA is responsible for ensuring the safety of foods that enter into “interstate” commerce. The assessment that foods are free of pathogens relies heavily on testing hence method development tends to evolve parallel to food safety regulations. Rapid methods are more sensitive than conventional assays, but the increased sensitivity has also created interesting challenges and problems for the regulatory agencies and the food industry.

Stress, Infectivity and Sample Preparation

9:30 Impact of Stress on Detection of Pathogens

Arun Bhunia, PhD, Professor of Food Microbiology, Department of Food Science, Department of Comparative Pathobiology, Purdue University

For microbial pathogen detection, biosensor platforms rely on antibodies, nucleic acids or aptameric probes for capture and detection. However, microbes or microbial biofilms originating from food or environmental sources are often pre-exposed to various physical and chemical stressors, which alter microbial growth, morphology, and physiology and virulence protein expression. Therefore, stressors can significantly affect biosensor performance thus may yield false-negative results. Strategies to overcome such shortcomings of biosensor performance in relation to pathogen’s growth and behavior under various stressful conditions will be discussed.

10:00 Networking Coffee Break

10:30 Generation of VBNC Pathogens While Maintaining Infectivity during Food Processing

Bill Keevil, PhD, Professor, Centre for Biological Sciences, University of Southampton, UK

We have developed a sensitive direct qPCR methodology without pre-enrichment for foods and growing media. Moreover, it is now recognized that during the biofilm mode of growth a sub population of cells become quiescent and resilient to antimicrobial treatment. They spontaneously enter a reversible dormant state which is refractory to antibiotic treatment that usually relies on active growth of bacteria to be effective. Persistence occurs through toxin-antitoxin modules and other dormancy pathways which are now proving amenable to the development of new classes of antibiotics. This presentation will explore this important and rapidly developing area of microbial dormancy to understand microbial survival mechanisms during food processing while maintaining their disease potential using suitable animal models.

11:00 Genome-Scale Identification of Essential Genes in Salmonella Tennessee Required for Infection of Human Macrophages - Linking Biomarkers of Relevance to Food Safety Risk

Seamus Fanning, PhD, Professor, Food Safety and Zoonoses, School of Public Health, University College Dublin

Transposon Directed Insertion Sequencing (TraDIS) is a powerful, high throughput genetic screening technique in functional genomics which combines signature-tagged mutagenesis with novel sequencing-based approaches for transposon mutant identification enabling genome-scale assaying of fitness in selection experiments. It can be applied to large pools of mutants allowing the simultaneous assay of every single gene in the isolate. Here, we describe the analysis of TraDIS data following the infection of human THP-1 macrophages with a high-density library of Salmonella Tennessee CFSAN001387 (S. Tennessee CFSAN001387). From recovering viable intracellular bacteria during infection, we measured the cumulative fitness requirement of the bacterial genome for up to 5 days post infection. TraDIS identified genes that effect the survival of S. Tennessee CFSAN001387 ex vivo when compared with in vitro laboratory growth conditions.

11:30 Advances in Pre-Analytical Sample Preparation: Unclogging the Bottleneck from Sample to Answer

Byron Brehm-Stecher, PhD, Associate Professor, Rapid Microbial Detection and Control Laboratory, Iowa State University

Successful detection of pathogens in foods involves the seamless integration of three interdependent steps: 1) statistically validated sampling, 2) pre-analytical sample preparation and 3) detection. Weak links in any of these three steps will propagate through the system and degrade the end result. In a worst-case scenario, this could lead to false-negative results. “Upstream” methods for sampling have long been established, and the past decade has seen a revolution in development of the hardware and reagents needed for truly rapid detection of pathogens. However, even the most sophisticated detection methods cannot reach their full potential without next-level advances in pre-analytical sample preparation, which is still the key bottleneck in getting from sample to answer when detecting pathogens in foods.

12:00 pm Luncheon Presentation (Sponsorship Opportunity Available) or Enjoy Lunch on Your Own

Spectral Methods, Colorimetric and Electrochemical Detection, Microbiomics

1:55 Chairperson’s Remarks

Arun Bhunia, PhD, Professor of Food Microbiology, Department of Food Science, Department of Comparative Pathobiology, Purdue University

2:00 Spectral Imaging Technologies for Food Safety Evaluation of Agricultural Products

Jianwei Qin, Ph.D., Agricultural Engineer, Environmental Microbial and Food Safety Laboratory, USDA Agricultural Research Service (ARS)

Researchers at the Beltsville Agricultural Research Center have developed spectral-imaging-based techniques that target the reduction of food safety risks in post-harvest production and processing. Objectives of the current research include comprehensive safety and quality inspection for online processing of fresh fruits and leafy greens, authentication of food ingredients and detection of food contaminants, and improvement of cleaning and sanitation efficacies in food processing facilities. The current states of the above spectral imaging technologies are presented.

2:30 Rapid Process-Inline Pathogen Detection Using AI-Driven Low-Cost Optics

Kantha Shelke, PhD, Adjunct Faculty, Johns Hopkins University; Principal, Corvus Blue LLC

Harjeet Bajaj, President & CEO, Executive, Savormetrics

Produce handlers and processors are a hotspot for microbial contamination leading to foodborne illnesses which in turn can lead to severe health ailments including deaths. The economic costs include health care costs, wasted food costs, and PR costs associated with recalls and damaged reputations. Implementing ultra-affordable indicator based technologies, IoT connected to QA/QC protocol monitoring systems, and installed inline at various stages of the food processing wash process, can help mitigate these costs substantially. The technology can help identify pathogens on produce as well. Policy makers and regulators will value the opportunity to implement protocols and enforce them without the barriers of enforcing changes to processes and extensive capital outlay requirements.

3:00 Opening Refreshment Break in the Exhibit Hall with Poster Viewing

4:00 Rapid Detection of Salmonella in Large Volume Samples Using a Flow-Through, Enzyme-Amplified Immunoelectrochemical Biosensor

Andrew Gehring, PhD, Research Chemist, Lead Scientist, United States Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center

Enzyme-based immunoassays are highly desirable for the detection of foodborne pathogens as they offer shorter response times compared to traditional culture-based methods. Biosensors employing the electrochemical detection of a substrate oxidized by horseradish peroxidase (HRP) have been used to successfully detect biomolecules; however, their inability to handle large sample volumes severely limits their application to food safety despite their accuracy and reliability. Here, we describe a biosensor with the capacity to process a large sample volume by utilizing a porous working electrode made from carbon coated with antibodies specific for Salmonella common structural antigens. This design allows samples to flow-through the electrode while capturing target pathogens. The low cost of the sensor allows for incorporation into disposable detection devices while its design not only broadens its applicability in sample processing but also permits the detection of various microbes by simply exchanging the antibodies.

4:30 Colorimetric and Electrochemical Bacteria Detection Using Printed Paper- and Transparency-Based Analytic Devices

Bledar Bisha, PhD, Assistant Professor of Food Microbiology, University of Wyoming

The development of transparency-based electrochemical and paper-based colorimetric analytic detection platforms is presented as complementary methods for food and waterborne bacteria detection from a single assay. A colorimetric paper-based well plate system was developed from a simple cardboard box and smart phone for the detection of PNP and ONP. Colorimetric detection limits were determined to be 81 μM and 119 μM for ONP and PNP respectively. While colorimetric detection methods gave higher detection limits than electrochemical detection, both methods provided similar times to positive bacteria detection. Alfalfa sprout and lagoon water samples served as model food and water samples, and while water samples did not test positive, sprout samples did test positive within 4 h of pre-enrichment. Positive detection of inoculated (2.3 × 102 and 3.1 × 101 CFU/mL or g of E. coli and E. faecium, respectively) sprout and water samples tested positive within 4 and 12 h of pre-enrichment, respectively.

5:00 Applications of Food Microbiomes for Food BioDefense: Lessons from Spoiled Foods

Gregory Siragusa, PhD, Senior Principal Scientist, Microbiology, Eurofins Microbiology Laboratories

For the food microbiologist, cultural microbiology of unknowns has always been a cat-and-mouse game of aligning cultural media requirements with atmosphere, temperature, pH, redox, etc. However, once the microbiologist has even a minimal indicator of the target’s identity, culture is often straightforward, albeit time consuming. The advent of microbiomics (discussed at this meeting) has provided means to resolve unknown mixtures of microorganisms without culture. Where large viable numbers of intentionally spiked pathogenic bacteria are used in food or water in an offensive mode, a major advantage of this approach is that no prior knowledge of bacterial type is needed. The process of performing a microbiome also takes advantage of large differences in the ratio of target to background. Here is presented examples of chronic spoilage issues that have proven recalcitrant to standard cultural microbiology.

5:30 Welcome Reception in the Exhibit Hall with Poster Viewing

6:30 End of Day

Thursday, June 28, 2018

8:30 am Morning Coffee

Identification & Management of Emerging and Re-Emerging Pathogens

8:55 Chairperson’s Remarks

Willy A. Valdivia-Granda, Founder and CEO, Orion Integrated Biosciences, Inc.

9:00 Sequence-Based Method to Predict Host-Pathogen Interactions Between Group IV Viruses and Various Hosts

Patricia Legler, PhD, Research Biologist, Naval Research Laboratories

The alphaviral nonstructural protein 2 (nsP2) cysteine proteases (EC 3.4.22.-) are essential for the proteolytic processing of the nonstructural (ns) polyprotein. A common secondary role of these proteases is in interferon (IFN)-antagonism. Here we identify a new host substrate of the nsP2 protease, human TRIM14, a component of the mitochondrial antiviral-signaling protein (MAVS) signalosome. At least eight other Group IV (+)ssRNA viral proteases have been shown to cleave host proteins involved in the innate immune response and the antagonistic strategy may be akin to those of CRISPR/Cas9 and RNAi/RISC, but with a protease recognizing a cleavage site common to both host and virus.

9:30 Use of IFN-Expressing Vectors in Control of Ebola Virus Disease in Swine

Chandrika Senthilkumaran, PhD, Research Scientist, National Center for Foreign Animal Disease, Canadian Food Inspection Agency

Ebola virus (Kikwit) can replicate in domestic pigs. Infected pigs shed the virus as early as 3 days post infection (dpi) and transmit the virus to animals including non-human primates cohabiting with them. In the event of an intentional or accidental exposure of pigs delaying or preventing the spread of infection in pigs by preventing the shedding of virus is an absolute necessity. In our study we proved that the Porcine Interferon alpha delivered with a replication defective human adenovirus (Ad5-porIFN α) is an effective bio therapeutic agent to prevent shedding of Ebola virus from infected pigs.

10:00 Sponsored Presentation (Opportunity Available)

10:30 Coffee Break in the Exhibit Hall with Poster Viewing

11:15 Microbial Contamination in Surface Water – Challenges and Scope

Pramod Pandey, PhD, Assistant Specialist CE, Department of Population Health and Reproduction, University of California, Davis

While decreasing water levels in rivers has been a major concern for many countries, contamination in surface water, particularly microbial contamination in streams is a serious issue. Solving the problems requires improved understanding of associated source of pollutions. This research is focused on understanding the effects of land uses on microbial contamination in streams, and developing mathematical tools for rapid detection of microbial pathogens in rivers.

11:45 A Cost Effective Method for Surveillance of Influenza Viruses A, B, C and D in Swine Oral Fluid Using Newly Developed Multiplex rRT-PCR Assays

Johnny Callahan, MT(ASCP), PhD, Veterinary Diagnostics Business Development Manager, APHIS/CVB Liaison, Tetracore, Inc.

The objective of this study was to develop cost effective methods for respiratory disease surveillance in swine oral fluid and respiratory swab samples, specifically for various types of influenza viruses. Here, we report on the development of a panel of multiplex rtRT-PCR assays that detect the conserved regions of all four types of influenza viruses. This panel of novel assays was designed to provide cost efficient testing to the producer and promote the continued surveillance for influenza viruses. Screening for various types of influenza viruses by rtRT-PCR is a first but vital step in surveillance. The producer will see cost savings when using the multiplex testing versus the singleplex. In conclusion, having well validated and rapid diagnostic tools such as these new multiplex rtRT-PCR assays will be vital for continued swine health and production while enhancing the One Health Initiative.

12:15 pm Close of Conference

5:15 Dinner Short Course Registration

6:00 Dinner Short Courses*

*Separate registration required