Questions and AnswersProf. Les Baillie

Your main research topic is anthrax. When talking about anthrax, what comes to mind are the biological weapons used by terrorists since September 11, 2001, which have caused 5 deaths. You are currently working on a project in eastern Turkey in a region where the anthrax causing bacterium Bacillus anthracis is endemic. Isn´t that dangerous?
To tell you the truth: we don´t know. The so-called “Ames Stream” of Bacillus anthracis, which is very dangerous and which had been used as biological weapon, was originally isolated from a cow in Florida. But we don’t know whether the strains in Turkey are as virulent, their is no reason to believe that they are not so we take precautions; we are vaccinated and we wear protective clothes and masks.
 

Why is Bacillus anthracis so common in this region?
The climate and soil support the survival of the pathogen. It´s very damp and cold in winter and the soil is rich in calcium-factors which are thought to play a major role in the environment survival of this particular bug along with its ability to form spores which can survive for many years. In addition the majority of the local farmers cannot afford to regularly vaccinate their cattle who are the many victin of this disease. That´s why the bug can persist in this region.
 

How do the people there live in such close contact with this dangerous bug?
It is somewhat surprising that our Turkish colleagues who are routinely exposed to the bacteria and are not vaccinated or wear protective clothes do not catch the disease. The same is true for the farmers in the region who live in close contact with their animals; during the winter months the animals often live in one half of the house and the people in the other. We don´t know yet why they do not get infected. There might be two reasons for that: One is that the strains in Turkey are not as dangerous for humans although this would not explain why seveal hundred human cases occur every year in Turkey. The other is that the bug is not deadly at low doses. Which means that you could be exposed to the bacteria with a subclinical infection and acquire immunity against it. But apart from the possible danger for the people living there, Bacillus anthracis is a big problem because it kills cattle. The subsistence farmers, who live there, do not have a lot of money, so losing a cow is a big loss for them. The other problem is that they do not have the facilities to properly dispose of the dead animals. They bury them in a hole in the ground. The spores then work their way to the surface over time and can infect other animals. We are trying to help our Turkish colleagues break this infection cycle.

 
Breaking the infection cycle, how do you do that?
The bacteria is able to survive soil for many years due to its ability to form spores which are able to resistant a range of environmental chemicals including most biocides. While we have tried to eliminate spores using chemicals we have also been exploring a more natural approach based on the use of bacteriophages which are viruses which only infect bacteria making them highly specific. In the laboratory we found a way to make the spores convert into a form which is susceptible to the actions of the bacteriophage. So now that we know that the approach is feasible, we plant to determine next year if it works in a real environment.
 

Using bacteriophages for eliminating bacteria, is this a new approach?
No, phages are already in use against Listeria in food decontamination. So the idea is not a new one. But we will try to apply this technique on thousands of hectares of land and that is new. There has never been a study carried out in the real world on surfaces of this dimension.
 

A number of vaccines against Bacillus anthracis exist. but there have been many discussions about it, because it seems to brought on some severe adverse reactions. Are there other vaccines being currently developed?
Yes, there are some but the development is very difficult as we don´t know much about the pathology of anthrax in humans as infection is very rare. We have a lot of data of immunized individuals because in the US all soldiers are given the vaccine. But we have relatively little data on the immune response of naturally infected people. As I already said, it might be that many of the people in this region in eastern Turkey have been infected with Bacillus anthracis someday in their life without knowing it. That´s pretty interesting for us. We try to get some funding to investigate the immune response of the people there. This could provide us with helpful data for the development of new vaccines.  

back