Bacterial Extract Could Provide Protection Against Anthrax

Researchers at the M.D. Anderson Cancer Center in Houston have developed a bacterial extract that when sprayed into the lungs of mice can protect them against the pathogens that cause anthrax and bubonic plague. Their research, which was presented at the American Society for Cell Biology's annual meeting, indicates that the extract derived from a common microbe can protect against four major classes of pathogens.

The spray is derived from a coccobacillus called Haemophilus influenzae, which has been identified as the cause of sinus and ear infection in children. The spray causes the immune system to react against the threat that these pathogens present, causing researchers to hope that the bacterial extract could some day help patients with compromised immune systems, such as those with cancer or AIDS.

Such a treatment could also act as a preventative measure for those people most likely to be exposed to anthrax or other bioterrorism attacks, such as government workers or people who live in large cites. However research indicated that the treatment works best if given four to 24 hours before exposure occurs, making its feasibility as an inoculation doubtable in its current form.

In the study, some mice were treated with the bacterial extract while others were not. The mice were then exposed to a number of different disease. For example when the mice were exposed to Streptococcus pneumoniae, 83 percent of the treated mice survived. None of the mice that did not receive the bacteria extract lived.

Most of the mice that were treated with the spray beforehand survived lethal doses of anthrax, influenza, and Aspergillus. The mice were tested on all four classes of pathogens, including bacteria, fungi, and viruses. Class A bioterror agents were also part of the tests.

Treatments given after exposure also had some benefit, but not as much as when given before exposure. The treatment's effectiveness also seems to decline after five days, although repeat dosages could occur to maintain effectiveness.

The spray works in the lung's airways, preventing common pathogens from killing cells within the lungs. However, it does not rely on neutrophils or other immune system cells. The patient's body only responds in the exposed area, the lungs, and does not cause many side effects. Even after repeated dosages, no serious side effects were apparent.

While only testing on mice has occurred, preclinical testing and clinical trials are all expected to follow.
Source:

American Society for Cell Biology, "Purified bacterial extract sprayed into lungs ramps up innate immune system", Eurekalert