Archive for April, 2008

Virus Eating Bacteria

Thursday, April 17th, 2008

The fear of resistant infectious bacteria is rising.  These can spread rapidly across countertops, stethoscopes, and catheters. These “superbugs” infect up to 1.2 million patients a year in the United States, according to a 2007 report from the Association for Professionals in Infection Control and Epidemiology, and they’re quick to evolve defenses against even the most powerful antibiotics.

Now scientists in Scotland have come up with an alternative to antibiotics, which may effectively stop bacteria in its tracks. Janice Spencer and a team of researchers at the University of Strathclyde are developing nylon sutures coated with bacteriophages–viruses, found naturally in water, that eat bacteria while leaving human cells intact. New research by the Scottish team found that phage-coated sutures effectively stemmed infection in live rats.

Bacteriophages are not a recent discovery. During World War II, Russian doctors used cocktails of these viruses to treat soldiers infected with bacteria such as dysentery and gangrene. However, researchers soon turned their attention from bacteriophages to the rapidly rising field of antibiotics, developing new classes of antibiotics to combat ever-more-resistant strains of bacteria.

In water, these natural-born killers are extremely effective at eating up bacteria. The virus binds to bacteria and injects its DNA, replicating within its host until it reaches capacity, whereupon it bursts out, killing the bacteria in the process.

Obtaining bacteriophage-laden water samples is easy, says Spencer. The challenge is in keeping virus molecules active out of water. In dry environments, the virus’s proteins tend to fall apart in a matter of hours, rendering them ineffective against bacteria. Spencer and her colleagues isolated bacteriophages from water samples and developed a novel method to keep them active.

The team chemically bound bacteriophages to microscopic polymer beads by first breaking the surface of the polymer. Then the researchers added a linker molecule to the polymer’s surface, which in turn binds to bacteriophages and keeps them from falling apart. To test the virus’s virulence, the team first made small incisions in live rats, then infected them with Methicillin-Resistant Staphylococcus Aureus (MRSA), one of the most resistant strains of bacteria found in hospitals. Half of the rats were stitched up with sutures that were coated with polymer-bound bacteriophages. The other rats were closed up with untreated sutures.  Sounds like an exiciting step forward.

Human Animal Cross-Breeding

Wednesday, April 2nd, 2008

For the first time in Britain, researchers at Newcastle University said they had created human-animal hybrid embryos, amid a political row over a disputed embryo research bill in parliament. According to the northern English university, the research, which was first presented at a lecture in Tel Aviv on March 25, has yet to be published or verified, with a spokesman for the university telling AFP that the institution “wouldn’t claim it to be final at all.”

The revelation comes with British MPs engaged in a fierce battle over the Human Fertilisation and Embryology Bill, which allows the creation of human-animal hybrid embryos for medical research. Prime Minister Gordon Brown’s governing Labour Party conceded in March that its party lawmakers with moral or ethical objections would be allowed to vote against parts of the proposed legislation when it comes before parliament this year.

The embryos were created by injecting DNA taken from human skin cells into eggs derived from cow ovaries with almost all their genetic material stripped away, and lasted for three days in a laboratory. The Newcastle University spokesman said that the research would likely be published in “months rather than weeks”. At present, researchers wanting to create such embryos have to apply for a license from the Human Fertilisation and Embryology Authority, which currently regulates the practice in Britain, and hybrid embryos have to be destroyed after 14 days. The government says that the scientific advantages of allowing the creation of hybrid embryos for research purposes could help millions of people to recover from illness or disease.

Religious leaders, however, have argued against the bill, with the leader of Catholics in Scotland, Cardinal Keith O’Brien, using his Easter Sunday sermon to brand the bill a “monstrous attack on human rights, human dignity and human life” which will allow experiments of “Frankenstein proportion”.  Can flying people be just a few decades around the corner?