new vdl lab

The University of Kentucky Veterinary Diagnostic Laboratory is excited to announce the opening of a New Pathogens Discovery Diagnostic Laboratory this fall.  The laboratory will serve as an extension to the existing UKVDL Molecular Biology, Virology and Bacteriology laboratories to help identify potential pathogens, both endemic and emerging, that may can cause morbidity and mortality in animals.

Pathogen detection will be done using cutting-edge Next Generation Sequencing (NGS) technology, metagenomics and bioinformatics methods. The Gluck Equine Research Center has plans for a similar laboratory, primarily for infectious disease discovery research.

Traditionally, the identification of infectious disease agents in specimens/animals submitted to the UKVDL has been done through microscopic observation (morphology and Gram stain), bacterial media culture, viral cell culture, polymerase chain reaction (PCR) and other traditional diagnostic methods. 

Reliable cultivation of bacteria was first done by Louis Pasteur and Robert Koch in the late 19th century, and both were named the Fathers of Microbiology for their contributions. 

The first virus (vaccinia) was grown in cell culture in 1913. The PCR method was discovered in 1985 by Kary Mullis, an industrial chemist. Unfortunately, conventional bacterial and viral cultures can take days, weeks and even months to lead to pathogen identification and sometimes grow nothing at all. Unlike culture, PCR can only identify specific agents that might be suspected. 

In 2015, the UKVDL acquired a MALDI-TOF instrument (Matrix-Assisted Laser Desorption/Ionization-Time of Flight) for identification of culturable bacteria and fungi by using mass spectrometry and laser technology. The instrument can identify most agents within minutes, improving the turn-around time by about 24 hours. However, the organism must first be cultured, which still requires about 24 hours or more depending on the microorganism.

            The implementation of NGS and leading-edge bioinformatics systems in the new UKVDL laboratory will assist UKVDL pathologists and microbiologists and Gluck scientists in the discovery of new pathogens and identify known pathogens more precisely than traditional methods. It will also enable innovative disease surveillance methods for endemic and emerging animal diseases.

Metagenomics is a method to study organisms that are difficult or impossible to culture, some of which may be potential pathogens. We are happy to announce that Litty Paul, PhD, an experienced investigational biologist, has been recruited to the UKVDL to design and launch the new NGS laboratory.

Tissue samples from sick or deceased animals are sent to a diagnostic laboratory by a veterinarian or an owner curious about the cause (etiology) of an illness or death loss. Once this new method is validated, the laboratory will extract and sequence the genetic material from the samples and store them in databases. The databases will then be analyzed by state-of-the-art bioinformatics software that can identify and classify the community of microorganisms present in the samples, which can aid in disease diagnosis. Even more powerful is the ability to compare analyses from sick and healthy animals to help identify and characterize new and emerging pathogens.

 

 Several of the 60-member veterinary diagnostics laboratories (VDLs) of the National Animal Health Laboratory Network (NAHLN) are already utilizing this technology.

This past spring, many Bluegrass horse farms were experiencing outbreaks of severe diarrhea in very young foals, and traditional diagnostic tests were not useful in providing the answers. Samples were gathered systematically from many local Thoroughbred farms by Emma Adam, DVM, PhD, DACVIM, DACVS, assistant professor, research and industry liaison at the Gluck Equine Research Center, and brought to the UKVDL for testing in the microbiology laboratory of Erdal Erol, DVM, MSc, PhD, head of diagnostic microbiology and professor at the UKVDL.

He then forwarded select samples to the Texas A&M VDL and the University of Missouri for electron microscopy (EM) for testing. Both labs identified rotavirus on EM. Oddly, all PCR tests for rotavirus group A run at UKVDL had been negative.  Feng Li, DVM, PhD, professor and William Robert Mills Chair in Equine Infectious Disease at the Gluck Center, sent fecal specimens to the South Dakota State University VDL for NGS and metagenomics analysis. This collaborative effort identified a novel group B rotavirus in the foal specimens. Until this time, only group A rotavirus was targeted by the UKVDL PCR test.

This is a prime example of the outstanding collaborative diagnostic effort among the UKVDL, Gluck Center and other institutions, and demonstrates how these new methods can rapidly identify a new, emerging pathogen.  

This data enabled Erol and Li to swiftly develop and validate a new PCR that can now identify the new group B rotavirus in about four hours. This test is now offered by UKVDL. The good news is the UKVDL is now prepared to detect the new virus in upcoming foaling seasons. 

Once NGS technology is in place at the UKVDL and the Gluck Center, new and emerging pathogens in horses and other animals will be detected faster and easier than ever before.

      

Erdal Erol, DVM, MSc, PhD, head of diagnostic microbiology and professor, and Litty Paul, PhD, both from the UK Veterinary Diagnostic Laboratory, provided this information.