Bacteria Vs Virus
Two types of normally disease causing bacteria are being manipulated to act as trojan horses in the fight against HIV. Genetically engineered to carry some of the gentic material from HIV these bacteria may represent a radical new kind of cheap vaccine that can be swallowed instead of injected.
David Hone and his colleagues at the University of Maryland Biotechnology Institute in Baltimorehave used a weakened form of Salmonella typhi, the bacterium that causes typhoid fever to produce a possibly vaccine. They hope to start testing the vaccine later this year in Nigeria and Uganda.
Meanwhile Yvonne Paterson and her colleagues at the University of Pennsylvania Medical School in Philadelphia have developed a vaccine based on Listeria monocytogenes. The vaccine has been shown to work as planned in mice. She is now applying to test the vaccine in macaques.
Vaccine (vol 19, p 1435)
Nosey Bugs are Good We Hear
A team of medical microbiologists led by Kristian Roos at the Lundby Hospital in Gothenburg, Sweden have given children suffering from Otitis media a nasal spray of Alpha-streptococci. Alpha-streptococci occur naturally in the ear and upper respiratory tract and they produce an enzyme that inhibits the growth of bacteria that cause otitis media, the spray increases their numbers to make this more effective.
Otitis media is an inflammation in the middle ear, it is the most common bacterial infection in children. Two thirds of those effected normally experience recurrent infections. It is hoped this spray could reduce the reoccurrence of the disease and at the same reduce the usage of antibiotics. This will reduce the speed with which bad bacteria can develop resistance to modern antibiotics.
British Medical Journal (vol 322, p 210)
Escherichia coli 0157 has its genes revealed
The genome of a potentially deadly strain of Escherichia coli 0157 has been sequenced by a team of scientists in USA led by Nicole Perna at the University of Wisconsin-Madison.
E. coli 0157:H7 produces toxins that cause bloody diarrhoea and kidney failure. It is mainly transmitted in infected meat and was responsible for the world's worst outbreak of E. coli food poisoning, killing 20 people in Scotland in 1996. In the US, it causes an estimated 75,000 infections every year.
The team found that E. coli O157:H7 is armed with an extraordinarily wide range of genes that help it trigger disease and resist destruction by the body.Nature (vol 409, p529)
Sweeter Smelling Sewerage Workers
Fetid sewers could be made to smell sweeter with regular injections of concentrated bacteria. Sewers which suffer from rotten-egg smell are the result of bacteria giving off hydrogen sulphide, but not all sewerage bacteria produce this as a waste product. By artificially keeping up the numbers of more pleasantly disposed bacteria in the sewers the producers of hydrogen sulphide can be greatly reduced. Thus improving the smell and reducing the corrosion that results when the hydrogen sulphide dissolves to form sulphuric acid.
In-Pipe Technology of Wheaton, Illinois, is testing the idea in Tampa, Florida. A continuous supply of a bacterial cocktail of between 10 and 14 species of bacteria is leaked into the pipes from dosing units sited strategically throughout the sewage collection system.
Investigators from the Civil Engineering Research Foundation in Washington DC are now assessing the technology independently.