Tag Archives: Undulant fever

Light triggers virulence in abortion-causing bacteria!

The world of microbes and animals still continue to not just entertain, but surprise us as well. The undulant fever or Malta fever-causing bacteria — Brucella — which is a bother especially for the developing countries, are found to possess an interesting feature – It can sense light! To add to it, the brucellosis-causing bacteria use this ‘light-sensed information’ to regulate its own virulence! To their surprise, a group of US and Argentinian researchers found that the bacteria is 10 times more virulent in the light, compared to what it is in the dark Since the bacteria was first spotted by British medical officers in Malta during the Crimean War in the 1850s, it is more than a century of research into brucella that causes high incidences of abortions, or calve weak offspring, arthritic joints, and retention of after-birth – called retained placenta — in livestock and fevers in humans. But, its fluctuating virulence-mystery is detected for the first time, i.e. its light-sensing capability. The light receptors of the bacteria have a molecular region — LOV — that was eventually discovered 10 years ago, but in plants, enabling them to grow toward light sensing day length. Although, the necessity of the bacteria to possess the same sensing ability is still not being discovered, this characteristic clearly shows that it allows brucella to know if it is outside its host – like, when a cow’s infected foetus has been aborted. When, it’s in the open lying in the field along with the aborted foetus, it increases its virulence form the light, getting ready to infect yet another fresh host. Image