Antibiotic Resistance Found In Black Plague
Pastor Dale Morgan
Antibiotic Resistance Found In Black Plague*
There is no vaccine, but antibiotics are useful for treatment and for
preventing the disease's spread. The researchers observe, "Our data
imply that high levels of MDR in the causative agent of plague may
rapidly evolve naturally, and present a vital biomedical, public health,
and biodefense threat."
by Staff Writers
Rockville MD (SPX) Mar 22, 2007
The ability to resist many of the antibiotics used against plague has
been found so far in only a single case of the disease in Madagascar.
But because the same ability is present in other kinds of bacteria from
a broad range of livestock, antibiotic resistance could potentially
spread to other Y. pestis and also other bacterial pathogens. In a paper
published March 21 in the new journal PLoS ONE, the authors say this
possibility "represents a significant public health concern."
Genetic ability to disable antibiotics, including multidrug resistance
(MDR) sequences, is carried on plasmids, small circles of DNA that are
passed easily between bacteria. In this study, the same MDR plasmids
found in the Y. pestis from Madagascar were also present in bacteria
such as Salmonella and Escherichia coli found in retail samples of beef,
pork, chicken, and turkey from several US states.
"What we've done is revealed a mechanism for the acquisition of
multidrug resistance in Y. pestis. Obviously, this is an event that
might have serious human health consequences. But the sequencing work
we've done has given us a way to monitor this plasmid in future," says
senior author Jacques Ravel of The Institute for Genomic Research (TIGR)
in Rockville, MD.
"The fact that we found a plasmid usually found in Salmonella in Y.
pestis is a big problem. It also raises a question about how this
happened, how it went from one to the other. But that's a question we
cannot answer in this paper," Ravel notes. He urges a new monitoring
program to track MDR in Y. pestis.
MDR Salmonella and E. coli have been found in droppings from wild geese,
raising the possibility that wild animals might be able to spread MDR
far beyond the livestock where it originated, Ravel notes.
"When we identified the first Y. pestis strain resistant to multiple
antibiotics, we warned that if this type of strain spreads or emerges
again, it would pose a serious health problem" says co-author Elisabeth
Carniel, head of the Yersinia Research Unit at the Institut Pasteur in
Paris. "The discovery that the multiresistance plasmid acquired by the
plague bacillus is widespread in environmental bacteria reinforces this
warning".
There have been many plague epidemics in human history, and Y. pestis is
believed to have killed an estimated 200 million people. Plague is now
regarded as a re-emerging disease, with small outbreaks all over the
world. Because plague is often fatal, Y. pestis is a potential agent for
bioterrorism.
There is no vaccine, but antibiotics are useful for treatment and for
preventing the disease's spread. The researchers observe, "Our data
imply that high levels of MDR in the causative agent of plague may
rapidly evolve naturally, and present a vital biomedical, public health,
and biodefense threat."
The paper resulted from an international collaboration among researchers
at TIGR, a division of the J. Craig Venter Institute, the Institut
Pasteur in Paris, the Agricultural Research Service of the US Department
of Agriculture, and the US Food and Drug Administration. This work was
performed at the National Institute of Allergy and Infectious
Diseases-funded Microbial Sequencing Center managed by TIGR.
The paper appears in the March 21 issue of PLoS ONE, the international,
peer-reviewed, open-access, online publication from the Public Library
of Science (PLoS). After publication, the paper will be available on the
PLoS ONE site (http://www.plosone.org) and at:
http://dx.doi.org/10.1371/journal.pone.0000309. DOI number:
10.1371/journal.pone.0000309