Dr. Miguel Valvano

The growing presence of drug-resistant pathogens continues to increase at an alarming rate, resulting in longer hospital stays, lost wages, and societal debt. Developing new strategies and therapies to combat these infections is the goal of researcher Dr. Miguel Valvano.

Chair and professor in the Department of Microbiology & Immunology at The University of Western Ontario and a Tier One Canada Research Chair in Infectious Diseases and Microbial Pathogenesis, Valvano is a leader in using molecular genetics tools to understand how microorganisms work.

Bacterium (or pathogens) capable of producing disease are everywhere. They can even be found in hospitals and many are highly resistant to antibacterial drugs. According to the World Health Organization, infectious diseases remain one of the largest health care threats in the world, causing more than one-third of all deaths.

"There are new types of opportunistic microorganisms that afflict our ever changing population, especially the elderly and people suffering and recovering from cancer, genetic diseases, or requiring organ transplants," says Valvano. "Understanding how microorganisms escape from host surveillance and resist treatment will provide us with the knowledge and tools to develop more effective ways to treat and prevent infections."

The areas of research Valvano and his team focus on include the mechanisms of infection in patients with a variety of immune suppression and genetic disorders, and microorganisms that have become extremely resistant to virtually any useful known antibiotic. This includes research on the pathogen, Burkholderia cepacia. B. cepacia does not infect everyone, but it is a major health risk for patients suffering from cystic fibrosis.

Its presence is associated with increasing deterioration of lung function, causing severe chronic lung inflammation. B. cepacia can colonize in the upper respiratory part of the body, including the nose and sinuses, and it can be transmitted from patient-to-patient, however the vehicle of transmission is currently unknown.

To date, Valvano and his lab team have discovered B. cepacia can survive in free-living amoebae and macrophages. This means, not only can it survive in our bodies, but also in the environment. He hopes to use this bacterium as a model system to study and understand bacterial-host interactions that occur under circumstances where the host is compromised.

Valvano’s research also involves studying mechanisms of biosynthesis to reveal how the lipopolysaccharide (LPS) molecule assembles on the bacterial cell surface. LPS is a complex glycolipid molecule located on the outer surface of many common bacteria, such E. coli. The outer surface membrane acts as armor to protect those bacteria from host defenses and antibiotic entry. Valvano and his team are currently studying the enzymes and other proteins involved in its synthesis.

Bacteria with defects in the LPS molecule are more sensitive to a variety of antibiotics and can be easily killed by the host’s immune defensive mechanism. When infections are present, LPS can stimulate uncontrolled host responses that cause a number of different clinical conditions ranging from flu-like symptoms to deadly septic shock. By understanding how LPS is made and assembled on the bacterial cell surface, Valvano hopes to design inhibitors that will interfere with the process and develop more effective or a new class of antibiotics.

Valvano earned his MD from the University of Buenos Aires, Argentina and acquired further specialization in Clinical Pediatrics with concentration on Infectious Diseases. His research program is co-sponsored by a special initiative "in memory of Michael O'Reilly" from the Canadian Cystic Fibrosis Foundation and the Institute of Circulatory and Respiratory Health. He also receives additional funding support from the Canadian Institutes of Health Research (CIHR), the National Science and Engineering Research Council, the Canadian Cystic Fibrosis Foundation, the Canada Foundation for Innovation, and the Ontario Innovation Trust. He is a Member of the Canadian Bacterial Diseases Network and recently served as Chair of the CIHR Microbiology and Infectious Diseases grant review panel (1997-2000).

For further information, please contact Dr. Miguel Valvano using the Email contact form or by phone at 519 661-3436 ext 83436