Ant-i Fungus

A newly-identified fungus discovered by scientists in the US may provide the perfect Trojan Horse for getting rid of ant and termite infestations without needing to resort to pesticides or dangerous chemicals. Previous attempts to use fungi to wipe out unwanted nests of ants and termites have failed because the animals normally avoid fungi like the plague, because the spores can proove lethal to the colony. They even post guards to sniff out and bar infected individuals from the nest. But before it produces any lethal spores, the newly discovered fungus secretes a substance which ants and termites find irrestible. They collect it and carry it back to the nest, and have even been known to turn it into a bed for the queen. Shortly afterwards, however, the fungus begins to produce spores which infect and kill every member of the nest. Even better, once the nest has been wiped out, the smell of the residual spores deters re-infestations by fresh colonies of insects. Paul Stamets, who made the discovery and has now set up a company to commercialise his green means of pest control, is currently screening different strains of the fungus to find specimens which are slower to begin spore production, which would provide sufficient time for nests to become loaded with fungus to ensure efficient and complete destruction of the occupants.

12th Dec 2004

Laptops Bad For your Fertility

A New York-based urologist warned this week that laptops could be bad for mens' sperm counts. Dr. Yefim Sheynkin studied 29 men in their 20s and 30s and found that using a laptop for an hour increased the temperature of the average scrotum by over 2.5 degrees celsius, potentially affecting fertility. Previous studies have found that raising scrotal temperature by as little as 1 degree celsius is sufficient to affect sperm formation, but the volunteers in the laptop study achieved this rise in temperature after just 15 minutes on the computer. The effects of temperature on sperm formation are well known. A 1999 study showed that American mens' sperm production can drop by over 40% during the summer, compared to the winter, and that in hotter temperatures sperm speed drops and the number of defective sperms increases. On the basis of their findings Sheynkin and his team argue that regular daily laptop use could lead to chronically low sperm counts and advise users to put their laptop on a table whenever possible. They are now planning a follow up study to find out to what extent regular laptop use can affect mens' fertility.

12th Dec 2004

Capture The Moment

Have you ever waited ages for the perfect picture and then missed the moment because you were a fraction of a second too slow hitting the button ? If this sounds like you then Kodak may have the solution with a new invention to be added to their future digital camera range, called BLILO, short for "burst last in last out". Once the BLILO button is pressed the camera continuously shoots pictures at the rate of 2 a second, storing them to a separate 32 megabyte memory card. Once 30 pictures have been shot, the camera starts overwriting the old images with new ones, indefinitely. Once the button is released the last 4 frames taken, one of which hopefully contains the crucial moment, are transferred to the camera's main memory.

12th Dec 2004

The MRSA (methicillin-resistant Staphylococcus Aureus) Problem

Mark - MRSA, or Methicillin Resistant Staphylococcus aureus, is a special variety of a very common bacterium. We come into contact with it every day, and a third of us have Staphylococcus aureus up our noses all the time! MRSA is just a small group of this bacterium that has become resistant to a common type of antibiotics. The bacteria itself isn't particularly nasty; it is just more resistant to treatment, which has implications when trying to find ways of preventing and treating infection. The problems Staphylococcus would cause on a day to day basis are wide ranging, and are one of the commonest causes of infection in normal healthy people. When we have a cut, it is usually our own Staphylococcus that infects us. The MRSA strain was first found early 1960s, which was the same time that the antibiotic methycillin was introduced. The reason there were a few isolates of the resistant strain so early on is probably due to methicillin being related to beta-lactin. Beta-lactin is a natural antibiotic produced by fungi; probably used as defence against bacteria. Therefore, Staphylococcus has been in contact with the antibiotic for a long time, allowing a few resistant strains to evolve. It is only since people have been repeatedly prescribed antibiotics that problems have arisen. The non-resistant strains die out, leaving the resistant strains behind.

Chris - When did MRSA become a big problem in hospitals?

Mark - it actually took quite a long time. For many years, the bacteria were only found occasionally, and only slightly more often in people in hospital than people not in hospital. MRSA started to appear in clusters of people in nearby beds, but the outbreaks were still small. The problem has increased as the resistant bacteria has been passed from patient to patient. The most significant method of transmission is via the hands of healthcare workers in general, not just doctors. If a patient has MRSA on their skin and receives care from a member of staff who forgets to wash their hands, the next patient they treat will have the bacteria passed onto them. It is important to distinguish between being colonised by bacteria and being infected by bacteria.
Studies have shown that people visiting hospital acquire a range of bacteria different from those they came in with. However, they do not develop a similar range of infections: having MRSA on your skin does not necessarily mean that you will become ill.

December 2004

Dr. Liz Sockett. Liz

Chris - What has the genetic information told you, and how can they be used in fighting infection?

Liz - We found that Bdellovibrio have lots of genes that make bacteria-dissolving enzymes. They also secrete a juice that breaks down chromosomes. These will both kill bacteria. Bdellovibrio don't look for any specific target sites on their bacteria prey, so there is no way for the bacteria to hide. Unfortunately, Bdellovibrio can't get into MRSA, but they can get into many others. We hope to use them on things like burns and leg ulcers, although more testing needs to be carried out. We might even be able to take genes and put them in the bacteria so they can attack MRSA.

Chris - What happens when the infection has cleared up?

Liz - If the Bdellovibrio burst out of the dead bacterium and can't find any more food, they just die. This makes it a self-terminating therapy that leaves no residue. They are likely to be best for wound infections, as eating them will kill good and bad stomach bacteria, and they also end up going down the loo [with unforeseen consequences].

December 2004

Bacteriophage (phage) Therapy

Nick - Bacteriophages are viruses that infect bacterial cells and kill them. The word bacteriophage literally means 'bacteria eater.'

Chris - How do they grow?

Nick - Phages attach to bacteria and inject their genetic material into the cell. The genetic material makes more copies of itself, bursts the cell open and goes into the environment. One phage gives rise to, say, 100 new phages, which inject their genetic material into 100 more bacteria and so on. This amplifying process is one of the great benefits to phage therapy. Putting one
phage into an infected wound will lead to a chain reaction that expands until all the bacteria are dead. This is in contrast to antibiotics, which become less concentrated and less effective the longer and further they travel into the body.

Chris - How would you give the phage to the patient?

Nick - More trails are needed before we can start administering phages to patients, but we will probably start by putting them on surface wounds. This could be achieved by impregnating wound dressings with the phages. Once the bacteria have gone, the phages also die out. Another avenue we are exploring with regards to MRSA is trying getting rid of it in the nose. The phages will be delivered through a plastic inhaler. So far, it has been tried out on a couple of student volunteers which remained negative for MRSA for the few days we looked at them. We are going to do longer controlled trails and are
desperately trying to get it into hospitals. If the nasal inhaler is given to visitors, staff, and patients, the levels of MRSA in hospitals will hopefully decrease.

Chris - Will the bacteria become resistant to the phages like they have to some
antibiotics?

Nick - The bacteria will become resistant, but phages are living and can mutate too. Therefore, the bacteria and phages will fall into an evolutionary arms race whereby both bacteria and bacteriophages will evolve methods to outwit the other. As long as phages can keep up, they will always be a threat to the bacteria.

December 2004