Presented to Nizet at the Society's annual meeting last month in Baltimore, the award recognizes young physicians who have made outstanding contributions in clinical or basic research in pediatric infectious diseases.
Nizet Investigates bacteria that produce disease in children, with a particular focus on the pathogens group A and group B streptococcus (strep). Group A strep is the cause of strep throat and invasive infections including necrotizing fasciitis ("flesh-eating disease"), while group B strep is the leading cause of serious bacterial infections in newborn infants. Using molecular genetic methods, Nizet and colleagues discovered different sets of genes in each bacteria that produce potent toxins capable of injuring human cells.
"Our goal was to prove that specific genes were necessary and sufficient for the production of these toxins," Nizet said. "We did this by removing the genes from the strep bacteria and found that the bacteria no longer produced the toxin. The toxin-deficient strains were then found to lack the ability to produce injury or disease in animal models of human strep infection."
The Nizet group also took the genes they had identified and cloned them into other bacteria that normally don't produce toxins. With the new genes added, the benign bacteria became a toxin-producing factory.
As a result of Nizet's findings, researchers now have a better understanding of the two strep bacteria, which he believes will aid in the search for new treatments and disease prevention that specifically target the newly identified toxins.
In addition to these studies, the Nizet group investigates two additional areas - anti-microbial peptides called cathelicidins that provide the body's first line of defense against invading bacteria, and the mechanism by which group B strep crosses the human blood brain barrier to produce meningitis.