AVC is home to a unique clinical diagnostic tool that allows the College’s Diagnostics Services Unit to respond to clients’ needs more efficiently and cost-effectively.

Housed in a laboratory on the third floor of the College is a Bruker Daltonics® Microflex LT—a MALDI-TOF (Matrix Assisted Laser Desorption/Ionization Time-of-Flight) mass spectrometer used primarily to identify bacterial and fungal pathogens. This innovative system includes a built-in searchable database, called BioTyper™, which can quickly identify any microbes in a sample.

It works like this: when a sample comes into the AVC Diagnostic Services Bacteriology and Mycology Laboratory, it is plated and put in an incubator to allow any bacteria present to grow into visible isolated colonies. Once this is done, a tiny amount of the colony is placed on a stainless steel “target” that slides into the mass spectrometer. Inside the machine, the sample is bombarded by a nitrogen laser. This laser “desorption” liberates a spectrum of proteins which travel up a “flight tube” to a detector that registers the “time-of-flight” of each protein. Each protein has a different weight and therefore flies up the tube at a different speed. Once the spectrometer has collected a protein spectrum--or fingerprint--from a sample, the BioTyper software searches the database until it finds a match and provides a corresponding genus and species name.

The beauty of this system for clients is that more clinical samples can be processed in shorter period of time--96 bacterial identifications can be done in less than two hours.

Dr. Jeff Lewis, Associate Professor, Microbiology and Vaccine Development in AVC’s Pathology and Microbiology department, says AVC was the first organization in North America to use this innovative technology for in vitro clinical diagnostics. The application, which originated in Germany, was already being used in Europe.

Dr. Lewis came across this instrument in early 2007 and was impressed by its potential for clinical diagnostics. A serendipitous meeting in April of 2008 with Dr. Gerry Johnson (then Chair of Pathology and Microbiology) and subsequent efforts of Dr. Anne Muckle (Clinical Microbiologist at AVC) resulted in funding from ACOA to purchase the system. The mass spectrometer, with its accompanying database, was installed at AVC in May of 2008, and validated in 2009.

The value of the technology for clinical diagnostics has far exceeded Dr. Lewis’s expectations.

“In my opinion, the mass spectrometer has been a significant success,” he says. “It is used daily by our Diagnostics Unit as a front-line identification tool for bacteriology. It is rare that the potential of new technology is fully realized. This success represents a culmination of expertise, timing, unparalleled training and support from Bruker Daltonics, and perhaps most importantly the commitment and participation of key people at AVC, like Beatrice Despres (Department of Pathology and Microbiology bacteriology research technologist), and members of the AVC Diagnostic Services Unit (Jan Giles, Lorraine Lund, Matt Saab).We were also fortunate to have AVC veterinary students Emily Weidhass and Jessica Cady participate in validation efforts in the summer of 2009.”

The technology has been a boon to clients of AVC’s Diagnostic Services Unit, but AVC has made its own contribution to the system, says Dr. Lewis. Users have been building on the existing database by adding pathogens unique to this region.

The MALDI-TOF clinical diagnostics technology is now being used by other labs and research centres in North America, including the Centre for Disease Control and Prevention in Atlanta, Georgia, and the National Microbiology Laboratory in Winnipeg, Manitoba. Several human hospitals are currently validating the technology in Ontario, and the Ontario Veterinary College at the University of Guelph purchased the instrument in January 2011.

“The power and breadth of application of this technology has evolved considerably since AVC began using it in 2009. The histological potential of the new machines is astounding. We hope to capitalize on our expertise in clinical proteomics and identify the means to bring newer technology into AVC that will broaden both clinical and research uses.”