BioterrorismHow anthrax spores grow in cultured human tissues
Cultured human lung cells infected with a benign version of anthrax spores have yielded insights into how anthrax grows and spreads in exposed people. The study will help provide credible data for human health related to anthrax exposure and help officials better understand risks related to a potential anthrax attack. The study also defined for the first time where the spores germinate and shows that the type of cell lines and methods of culturing affect the growth rates.
Cultured human lung cells infected with a benign version of anthrax spores have yielded insights into how anthrax grows and spreads in exposed people. The study, published in the Journal of Applied Microbiology, will help provide credible data for human health related to anthrax exposure and help officials better understand risks related to a potential anthrax attack.
The study also defined for the first time where the spores germinate and shows that the type of cell lines and methods of culturing affect the growth rates.
“What we’re learning will help inform the National Biological Threat Risk Assessment — a computer tool being developed by the Department of Homeland Security,” said Tim Straub, a chemical and biological scientist at the Department of Energy’s Pacific Northwest National Laboratory. “There is little data to estimate or predict the average number of spores needed to infect someone. By better understanding exposure thresholds, the ultimate goal is to be able to predict outcomes from terrorist incidents involving Bacillus anthracis.”
A PNNL release reports that there are decades of data characterizing anthrax exposure in rabbits, but there is limited understanding of how this data extrapolates to humans. When researchers delved into this, working from cultured normal lung cells from each species, they found that, at low doses, the proliferation of anthrax spores is lower in human lung cells.
It is too early to say what that means for human health, but the study’s methods and results may resolve a long-standing debate on the pathogen’s propagation. Researchers showed that anthrax spores germinate in the lungs before making their way to the bloodstream. That has been a point of debate in the research community, with some speculating that spores, which are invisible to the naked eye, must first enter the blood stream and then grow into bacteria that can cause damage and death.
Knowing the precise location and pathway of spore germination and understanding that the bacteria begin producing toxins that damage tissue directly in the lungs may eventually impact treatment options. The finding also likely indicates added susceptibility in individuals who already have lung issues, such as smokers or those with asthma.
