Group B streptococcus (GBS) is the most common life-threatening bacterial infection in newborns worldwide. GBS typically resides in the lower genital tract but does not cause infections in healthy women. But if the infection is transmitted to an infant during pregnancy, it can lead to preterm birth or stillbirth. If the infection is transmitted to a newborn, it can cause pneumonia, sepsis or meningitis, all of which can occur within the first week of life or within 90 days of birth. The goal of my research is to prevent maternal to infant transmission of GBS.
But not all babies become infected. In the U.S. and other developed countries, pregnant women are screened for GBS around the 37th week of gestation. If found positive, a pregnant woman is given antibiotics during labor to prevent the newborn from being infected, and that has reduced transmission of GBS from mothers to infants during birth. However, infections that occur earlier than 37 weeks or after 1 week of birth are not prevented by these measures.
Preventing premature births and stillbirths
To prevent GBS infections in utero, I’m trying to better understand GBS and how infections occur before birth. Most bacteria that infect humans produce toxins known as hemolysins, which typically are proteins. What we found with GBS is that it is not using a protein toxin to kill host cells, as previously believed, but it’s using different cell component known as a lipid. This finding has changed the way we think about GBS.
I hope discoveries like this could one day be used to prevent premature births and stillbirths and newborn infections. I’ve been studying this bacteria for 15 years. I want to say here’s what you do to prevent GBS infections during pregnancy. Unfortunately, we are not there yet.
I am a basic science researcher, but one of my key collaborators is an obstetrician and gynecologist, Dr. Kristina Adams Waldorf of the University of Washington. She can tell me what is going on in the clinic because she may see a pregnant mother or baby with GBS and can offer me more information about what we can do on the research side that could be translated to preventing this disease. That collaboration helps me ask the right questions.
In search of a vaccine
When babies are born, their immune systems are just beginning to develop and they don’t know how to react to agents such as GBS. We want to give them a fighting chance and I believe we should do everything we can to protect them.
I’m fascinated by microorganisms that infect humans and want to understand how they do it so that we can develop measures to prevent infections. If my research on GBS is successful, then we could potentially have a vaccine to prevent women from transmitting this bacteria to their unborn or newborn babies.