December 22, 2008, Cambridge, UK – A new report demonstrates how a sensitive imaging technique gives scientists the upper hand in seeking out bacteria in chronic infections.
Listeria monocytogenes is a type of pathogenic bacteria that can cause severe illness and death. Listeria outbreaks recently claimed twenty lives in Canada. Additionally, Listeria infection is the third most common cause of bacterial meningitis in newborns, and can cause abortion and stillbirth. When the infection is caught in time, treatment can be difficult and take weeks to clear with intravenous administration of antibiotics.
Therefore, in order to understand how this pathogen can be so elusive and difficult to treat, a research team from Stanford University School of Medicine studied mice infected with Listeria. Their report published in the journal Disease Models & Mechanisms (DMM), dmm.biologists.org describes how they use a technique called in vivo bioluminescence to light up bacteria and allow them to see extremely tiny amounts of bacterial cells in living animals. Using this method, they found that small persistent patches of Listeria took up residence inside bone marrow in the mice. This is significant because it is thought that the bone marrow can act as a reservoir to the brain and spinal cord, potentially causing life-threatening infections, such as in bacterial meningitis in newborns.
Another interesting aspect of this study is due to the use of specially designed Listeria stains in treating cancer. Clinical trials are currently underway in which non-disease-causing strains of Listeria are administered to cancer patients to generate immune responses against tumors. The researchers thus also looked at these attenuated strains, and found that they too could be harbored in bone marrow. It is still unclear, however, if such bacterial persistence will increase or decrease therapeutic effects.
Commentary on this work will be featured in the DMM Podcast for Volume 2, Issue 1/2 of DMM. Podcasts are available via the DMM website at: dmm.biologists.org.
The report was written by Jonathan Hardy, Pauline Chu, and Christopher H. Contag of the Stanford University School of Medicine in California. The report is published in the January/February issue of a new research journal, Disease Models & Mechanisms (DMM), published by The Company of Biologists, a non-profit based in Cambridge, UK.
About Disease Models & Mechanisms:
Disease Models & Mechanisms (DMM) is a new research journal publishing both primary scientific research, as well as review articles, editorials, and research highlights. The journal's mission is to provide a forum for clinicians and scientists to discuss basic science and clinical research related to human disease, disease detection and novel therapies. DMM is published by the Company of Biologists, a non-profit organization based in Cambridge, UK.
The Company also publishes the international biology research journals Development, Journal of Cell Science, and The Journal of Experimental Biology. In addition to financing these journals, the Company provides grants to scientific societies and supports other activities including travelling fellowships for junior scientists, workshops and conferences. The world's poorest nations receive free and unrestricted access to the Company's journals.
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Disease Models & Mechanisms