I thought I would use my first post to introduce myself and explain the reason(s) for infectious thoughts. I am a research scientist with a background in medical and environmental microbiology. I’ll come back to what I do and what I’m interested in a bit later. As well as microorganisms, I am also obsessed with bioluminescence (the production of light by living organisms – think glow worms and fireflies). I feel immensely privileged to have made a career out of combining these two passions, as in a nutshell, I make bacteria glow in the dark for a living. After many years working in the UK, I was recently awarded a Hercus Fellowship from the Health Research Council (HRC) of New Zealand and relocated to the University of Auckland (UoA). It goes without saying that the views I will be expressing are my own and in no way represent the views of the UoA or the HRC!
So why would glowing bacteria be useful? Well, for a start, we could see them coming! Actually, that is closer to the truth than you might expect. Tagging bacteria with the genes for bioluminescence allows us to use light as a surrogate for actually physically counting the numbers of bacteria present in a sample, which is what you do after plating samples onto selective agar. Instead we can use a luminometer or charged coupled device (CCD) camera to give us a measure of light intensity (relative light units [RLU]). One of the first things we have to do is determine the relationship between light and bacterial numbers, but once this is done we can get a pretty good idea of how many bacteria are present using the RLUs. This can be especially useful if the bacteria take many weeks to grow on an agar plate, like Mycobacterium tuberculosis (the agent of TB) does. The other neat thing about luminescence is that only living organisms will glow so it can be an easy way to tell if something is dead or alive. This feature formed the crux of my PhD research which involved generating bacterial biosensors to monitor the toxicity of industrial effluents from a wastewater treatment plant. The more toxic the industrial effluent, the less the bacterial sensors glow. While it wasn’t great for the company, or indeed, the river into which the treated wastewater is discharged, during my studies the treatment plant failed and it was fantastic to find that my sensors would have been able to predict the failure. Shame though that they are genetically modified organisms and therefore highly unlikely to ever be used for real-time monitoring.
While I enjoyed my PhD studies, I came to realise I was more interested in bacteria that cause human disease so for my post-doctoral research I moved back to medical microbiology, the subject of my undergraduate degree. And this is where bioluminescent bacteria come in really handy. I am not ashamed to say that I am one of those scientists who work with mice. Providing they are used appropriately, animals are still very important in medical research. As someone interested in infectious bacteria, many aspects of the interactions between microorganisms and their hosts just cannot be replicated in a cell line. But we don’t use mice for everything; alternatives include worms and insect larvae. But when we do have to use mice, having bioluminescent bacteria is a bonus. If you haven’t tried this simple experiment before, give it a go: hold a torch up against your hand and you will see a beautiful red light coming out the other side. This is because light can travel through flesh. Not all wavelengths can get through though, hence why the white light ends up coming out red. We are fortunate that there are now sensitive CCD cameras available that can detect even very dim signals coming through flesh. This allows us to visualise where our bacteria are from inside an animal, a technique known as biophotonic imaging (BPI). Usually the animals are anaesthetised, but they can be imaged while awake too. Biophotonic imaging means we can use a lot less animals in experiments; instead of needing separate groups to take organs for plating onto agar plates at different time points, we can follow the bioluminescence from each animal and watch the bacterial numbers and locations change over time. In this way, we can often stop an experiment before the mice start to show any symptoms of disease, saving them from unnecessary suffering. My research is currently focused on using BPI to investigate three particularly nasty bacteria: Staphylococcus aureus (the hospital superbug MRSA), Streptococcus pyogenes (the flesh-eating bug) and M. tuberculosis.
So why blog? There are two reasons really. The first is to try to convey the wonder and admiration I have for microorganisms by writing about recent publications I have found interesting. However, the second reason is perhaps more important, in the grand scheme of things. Twice a day I have to walk past the Christian Science Reading Room (and no, I’m not going to change my route…). These misguided souls go on the teachings of Mary Baker Eddy (1821-1910) who wrote Science and Health with Key to the Scriptures, first copyrighted in 1875 and still in print today. These guys deserve a post all their own, but what really got my blood boiling was this sign in the window. Now Baker Eddy could perhaps be excused. Robert Koch, one of the founding fathers of microbiology, first isolated Bacillus anthracis (the agent of anthrax) two years after Baker Eddy’s first edition, in 1877, with the isolation of M. tuberculosis following in 1882 and Vibrio cholerae (the agent of cholera) in 1883. He was awarded a Nobel Prize in 1905. But what is the excuse of other editions?! As a microbiologist I am obviously a proponent of the germ theory of disease and believe vaccination to be one of the wonders of medicine.
Recently I read Trick or Treatment, by Simon Singh and Edzard Ernst, reviewing the evidence for the effectiveness of complementary and alternative medicine. Despite no evidence for the success of these treatments, they are widely used. In the final chapter, the authors list some reasons why this might be. Surprisingly, scientists are on their list. Singh and Ernst argue that alternative health practitioners are highly vocal and many of their claims go unchallenged. They believe scientists have a responsibility to make their voices heard too. I found Singh and Ernst’s call to arms inspirational. Instead of cursing under my breath at Baker Eddy’s disciples twice a day (amongst many other things…) I should be more vocal. SciBlogs seems a great forum for such an endeavour!