Veterinary college's researchers receive grant to explore bovine respiratory disease

Dr. Thomas J. Inzana

Dr. Thomas J. Inzana

BLACKSBURG, Va., April 3, 2008 – Dr. Thomas J. Inzana of Blacksburg, Va., the Tyler J. and Frances F. Young Professor of Bacteriology in the Department of Biomedical Sciences and Pathobiology in the Virginia-Maryland Regional College of Veterinary Medicine at Virginia Tech, has been awarded a grant from the United States Department of Agriculture to study the role biofilm plays in the development of Bovine Respiratory Disease Complex.

The $374,000 grant will allow Inzana and his fellow investigators, Drs. Indra Sandal and William Scarratt, to study the role of biofilm in the virulence of Histophilus somni (Haemophilus somnus), which is one of the bacteria responsible for the disease.

“If we can understand the protective or disease-enhancing effect a biofilm provides to H. somni then we can develop more successful and efficacious vaccines for this and other biofilm diseases,” said Inzana.

A biofilm is an organized community of bacteria that forms a glue-like substance that adheres to a variety of surfaces.

The plaque on your teeth is a biofilm, as is the slime that often forms on meat that has been left out too long. While some biofilms are harmless, they can also cause a variety of diseases in humans and animals, explains Inzana. Middle-ear infections and cystic fibrosis are both examples of biofilm diseases that can form in humans.

A biofilm can be particularly hard to treat because the bacteria are encased in an organized matrix that forms a protective architecture, resulting in enhanced bacterial resistance to antibiotics.

In bovines, Bovine Respiratory Disease Complex is a particularly troublesome disease that remains a major economic problem, despite years of extensive research, according to Inzana. It accounts for over 60 percent of all deaths in feedlot cattle, which leads to major financial losses for producers.

Inzana and his fellow researchers believe H. somni naturally occurs in a biofilm state within the bovine host. This may cause H. somni to be more resistant to treatment and host defenses because of the protection the biofilm provides. If left untreated, the bacteria can spread beyond the animal’s respiratory tract into the myocardium and the brain causing further damage and eventually death.

While vaccines against H. somni are currently on the market, none have proven to be adequately protective. Inzana and his team believe this is because of the lack of attention previously given to the role of biofilm in the disease process.

“Our goal is to understand the molecular basis for biofilm formation and to identify ways to prevent or treat the biofilm” said Inzana.

Inzana is quick to point out that the benefits of the research he and his colleagues are doing are not exclusive to bovine health. The study has the potential to advance the understanding of other biofilm diseases in animals and in humans, and it creates the possibility of using the bovine as a model to study human biofilm diseases, particularly those arising from host-specific bacteria, he said.

Inzana is also the associate vice-president for research programs in the Office of the Vice-President for Research. He is also the director of clinical microbiology for the veterinary college’s teaching hospital. In addition, from 1998-2002, Inzana served as coordinator of the school’s Center for Molecular Medicine and Infectious Diseases.

During his career, Inzana has also served as a visiting professor at the University of Pennsylvania School of Medicine and State University of New York at Buffalo School of Medicine. Inzana’s research interests are the development of improved vaccines for bacterial pathogens and biowarfare agents, the development of improved diagnostic tests for bacteria and biowarfare agents, the molecular basis of bacterial capsules and lipopolysaccharides in bacterial virulence, and the host immune response to bacterial pathogens.

He also studies the molecular basis for pathogenesis of Actinobacillus pleuropneumoniae, Francisella tularensis, and Burkholderia mallei. Inzana is board certified by the American Board of Medical Microbiology and Public Health and a Fellow of the American Academy for Microbiology. He is a member of the American Society for Microbiology, the American Association of Veterinary Laboratory Diagnosticians, the Conference of Research Workers in Animal Diseases, and the International Endotoxin and Innate Immunity Society.