Researchers have identified a genetic risk factor associated with premature birth.

The risk factor is related to a gene that codes for a protein that helps cells fight Group B Streptococcus (GBS) bacteria, a University of California San Diego news release reported.

This type of bacteria can be found in the vagina or gastrointestinal tract of between 15 and 20 percent of healthy women , but it can lead to problem such as sepsis and meningitis in newborns.

"Pregnant women are universally screened for these bacteria during pregnancy and administered antibiotics intravenously during labor if they test positive to protect the infant from infection," Victor Nizet, MD, professor of pediatrics and pharmacy and co-author said in the news release. "Our research may explain why some women and their infants are at higher risk of acquiring severe GBS infections than others."

The researchers identified two proteins on the fetal membrane of the placenta that were linked the immune system.

"We have one protein that tells the body to attack the pathogen and another that tells the body not to attack it," Raza Ali, PhD, a project scientist in the Nizet laboratory and the study's lead author, said in the news release.

The proteins, dubbed Siglec-5 and Siglec-14, are believed to help the body's immune system respond to pathogens by spurring

"Identifying the dual role of these receptors and how they are regulated may provide insight for future treatments against GBS," Ali said.

 Siglec-14 is absent in some individuals, and researchers believed these people run a higher risk of preterm birth.

"We found this association in GBS-positive but not GBS-negative pregnancies, highlighting the importance of GBS-siglec crosstalk on placental membranes," Ajit Varki, MD, Distinguished Professor of Medicine and Cellular and Molecular Medicine and study co-author said in the news release.

GBS infections only occur in humans and are not found anywhere else in the animal kingdom.

"The expression of the two siglec proteins on the fetal membranes is also unique to humans," Varki said. "Our study offers intriguing insights into why certain bacterial pathogens may produce uniquely human diseases."