The Spread of Superbugs, Cellular causes of Tinnitus and Precise Plant Pollination

The spread of superbugs from big city to small town, new drug target to treat Tinnitus, New insight into lunar cataclysms and the precise pollination of plants...
20 May 2012

Interview with 

Ross Fitzgerald, University of Edinburgh; Martine Hamman, University of Leicester; David Kring, Universities Space Research Association; Mark Johnson, Brown University


This 2005 colorized scanning electron micrograph (SEM) depicted numerous clumps of methicillin-resistant Staphylococcus aureus bacteria, commonly referred to by the acronym, MRSA


The Spread of Superbugs

Large city hospitals acts as breeding grounds for the highly resistant bacterium MRSA and facilitate its spread to more regional locations.

A study, led by Ross Fitzgerald from the University of Edinburgh, sequenced MRSAthe DNA of 87 samples of Methicillin-resistant staphylococcus aureus, or MRSA, from patients in over 15 hospitals across the UK.

The team deciphered the genetic make-up of the samples to trace the origins of infections found in more local settings and found that hospitals in big cities act as a hub for transmission of MRSA between patients who can then carry and transmit the bacteria to their local setting...

Ross - You don't have to actually have a disease to be infected with MRSA, but they can carry the MRSA with them to those regional hospitals.  We might be able to identify patients who become colonised when they're in these city hospitals.  If we can screen and identify patients who are MRSA carriers, we could then treat them using topical antibiotics to decolonise or remove those MRSAs so they're not then spreading them back to those regional centres.

---Cellular Causes of Tinnitus

The cellular mechanisms underlying the onset of tinnitus have been discovered by scientists at the University of Leicester, publishing in the journal
Hearing Research.

Working with nerve cells from the brain's dorsal cochlear nucleus, where signals are relayed from the ear to be decoded by the brain, Martine Hamann found that on exposure to loud sounds the erratic signalling in these cells, known to cause the ringing or buzzing associated with the condition, are caused by malfunctions in potassium channels within the nerve that normally regulate the its electrical activity.

Martina - You can have a variety of tinnitus.  It can be on one ear or on two ears.  It can be different frequencies, or the perception can actually be altered differently it can occur at different times of the day  So it's very difficult to pinpoint the mechanism, considering it is quite diverse.  So, finding something that is actually so specific can be quite promising in finding a specific target.

The work leads the way for potential drugs to restore the functioning of these channels, enabling the nerves to return to their normal state...

---Bombarding the Earth and Moon with asteroids

earthThe Earth and moon were bombarded with asteroids nearly 4 billion years ago, re-shaping their surfaces in the process.

It's known that our planet and the moon were bombarded with objects thought to be either asteroids, comets or protoplanets approximately 3.9 billion years ago.

Now, writing in
Science, David Kring from the Universities Space Research Association in Texas, analysed samples of moon rock from the Apollo 16 mission, which contained 30 surviving fragments of the colliding objects and identified the culprit to be asteroids - providing greater insight into our early solar system...

David - This is a period of bombardment that immediately precedes the earliest isotopic evidence of life on the Earth and so, we're constantly trying to address, could this bombardment have something to do with the origin and early evolution of life  To the extent that we can tease apart more details of the objects hitting, the pace at which they hit the Earth and the moon, and what it is they delivered to the Earth and the moon will better help us evaluate those questions.

---Precise Pollination

The precise way in which plants pollinate has been uncovered by scientists at Brown University in the US.

During pollination, hundreds of pollen-containing sperm stick to the stigma of plants such as Arabidopsis and create tubes through which they deliver sperm to the plants' ovules. Precisely two sperm per ovule, as any extra can result in poor seed development. But the way this is controlled was previously unknown.

Working with models of Arabidopsis in the lab, Mark Johnson and colleagues found that the plants generate a signal when sperm have successfully passed down the tubes to fuse with the egg inside the ovule to prevent any further pollen from landing.

Mark -  Plant fertilisation process waits until the moment when fertilisation has been secured to preven t multiple pollen tubes from coming.  So, in a case where defective sperm are delivered, that ovule continues to attract more pollen tubes.  So, if we can understand the molecular mechanisms that are the basis of these systems, we can then improve the systems or perhaps we can engineer them to be more robust and be able to resist adverse environmental conditions.

And that work was published in the journal
Current Biology.


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