The human body is a filthy place. The interrelationship of humans and the bacterial and microbial fauna that cover them has been well-documented, and in most cases our bacterial hitchhikers provide us with benefits far beyond aiding digestion. Some research has even shown that bacteria play a role in regulating the environment and climate.
Now, some new research has microbiologists alarmed: normally benign vaginal bacteria have been observed releasing tiny “balloons” that act as weapons, floating through the birth canal into the uterus and causing stillbirths.
According to research recently published by PLOS One, these balloons, or membrane vesicles, are loaded with poisons created by a strain of the Group B Streptococcus (GBS) bacteria commonly found throughout the human body:
In this work, we demonstrate that GBS produces membrane vesicles (MVs) in a serotype independent manner. These MVs are loaded with virulence factors including extracellular matrix degrading proteases and pore forming toxins […] Our findings suggest that GBS MVs can independently orchestrate events at the feto-maternal interface causing chorio-amnionitis and membrane damage leading to preterm birth or fetal death.
This bacteria is present in the birth canals of 20-30% of women, and doesn’t normally cause pregnancy complications or stillbirths; however, this research is the first to show that the bacteria actively creates ‘weaponry’ that seeks out the amniotic sac where it poisons embryos in utero. While scientists have discovered other weaponized bacteria in other organisms and environments, this research is some of the first to observe these bacteria releasing weapons specifically targeting the mammalian reproductive tract.
This discovery was made when researchers observed Group B Streptococcus bacteria in the birth canals of pregnant mice. The bacteria were seen to produce and release orbs of toxins that migrate through the vagina into the uterus. This discovery might help researchers develop a vaccine against Strep B bacteria; antibiotics alone aren’t enough to prevent an infection altogether, merely stop or slow infections once they happen.