'Invisible' bacteria dupe the human immune system

February 19, 2008

Scientists at the University of York have characterised an important new step in the mechanism used by bacteria to evade our immune system.

It is an ‘invisibility cloak’ which means that bacteria like Haemophilus influenzae, a common cause of ear infections in children, can move about the body without the risk of being attacked by the immune system.

A multidisciplinary research team from the Departments of Biology and Chemistry at York have been studying how bacteria capture the molecule used to make the ‘cloak’, called sialic acid.

The researchers have now discovered an enzymatic activity that helps in the more efficient capture of sialic acids released from our cell surfaces. As well as using the sialic acid to make the ‘invisibility cloak’ other bacteria use similar methods to capture sialic acid as a simple food source, so are literally eating us from the inside!

The research is published in the latest issue of the Journal of Biological Chemistry.

Dr Gavin Thomas, of the Department of Biology, who led the research said: “This novel enzyme, as well as other steps required for the formation of the 'invisibility cloak' that we have discovered in York, now offers the chance to develop novel antimicrobials against these bacteria.”

Source: University of York

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4 / 5 (1) Feb 20, 2008
I always have this fear that creating medicines against relatively harmless pathogens will cause them to evolve into more dangerous forms. I mean, these bacteria have coexisted - yes coexisted with humans for a very long time. It's hardly to their benefit to kill the host, but when we force them to evolve we are opening a Pandora's box of potential killer variants.

This is hardly an idle fear, given the myriad forms of drug resistant and more deadly versions of staph infections that constantly emerge in hospitals...

not rated yet Feb 25, 2008
Haemophilus influenzae is not harmless, but yes there are many harmless ones targeted, especially the idiocy of adding antibiotics to anything is a dangerous and dumb practice. Just to make a bit more money corporations take advantage of average persons ignorance (since those antibiotics are not helpful in anyway) at the same time polluting the environment with toxic chemicals, which can very well prove deadly to many organisms including humans if they accumulate to high enough levels.
They also increase selective pressure on pathogens to develop better resistance to antibiotics.
I'm really concerned with the number of chemicals that humans dump into environment, the current assumption is that if for compound X there is no proof of harmful effects its ok to manufacture tons of it many of which will end up in world water supplies or soil. The truth is that most of those chemicals will be toxic to some organisms, the life is so diverse that there certainly is some organism who happens to be unlucky enough to have a key enzyme shaped in a way that will make it susceptible to inhibition by compound X.
Many of those compounds will also prove harmful to humans but it may take 100 years or more before we have the data to back it up, by then many people will die due to ignorance and greed.

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