Health Desk-- April 29, 2017: Yersinia pestis, the bacterium that causes bubonic plague, can survive within the ubiquitous soil protozoan, the amoeba, by producing proteins that protect against the latter microbe's digestion.
According to the Centers for Disease Control and Prevention, the research is important because plague is a re-emerging disease and 95 percent of cases occur in sub-Saharan Africa and Madagascar.
Modern antibiotics are effective, but without prompt treatment, plague can cause serious illness, or death.
Y. pestis spreads from rodent to rodent, and sometimes to human, often via fleas It uses the protective niche of the amoeba to abide when conditions are unfavorable to its spread, that is, when rodents are scarce, said Viveka Vadyvaloo, PhD, Assistant Professor, Paul G. Allen School for Global Animal Health, Washington State University, Pullman.
She said, "This study serves as a proof of principle that amoebae can support prolonged survival of Y. pestis in the environment". It may encourage a search for this interaction within areas of Colorado and New Mexico where plague is endemic. And that, she said, could enable prediction of potential disease re-emergence, thereby reducing spread to humans.
The investigators also used electron microscopy to peer inside intact amoebae, and found Y. pestis within the vacuoles.
The research recently published in Applied and Environmental Microbiology.