Wednesday, 31 March 2010

DNA chip for the detection of fungi in the air.

This recent article (as yet uncorroborated by a published scientific paper) suggests that a device has been developed which can detect and identify several species of Aspergillus from samples of air. Similar devices are in development in other labs around the world for water samples (review) and other types of samples but this is the first indication that has come to our attention that this technology is to be used for air samples.

The technology (DNA chip technology.) is important because it can detect DNA when it is present in even very tiny amounts. This is particularly useful for working with very dilute samples such as large volumes of drinking water or air as it makes it possible to make accurate detections very quickly - the more established methods (e.g. culturing concentrated samples) would take weeks to achieve the same aim.

Very similar technology has been in use for some years in scientific laboratories to assist in complex fields of research such as cancer. Click here to view a movie of the fundamentals behind the many applications of this technology.

It can also detect specific sequences of DNA which is very useful when combined with DNA sequences that are only found in a single species as it then effectively becomes a tool for identifying specific species - in our case including Aspergillus versicolor & Aspergillus flavus.

Put both of these features on a tiny 'chip' on a single glass slide and you have a highly portable device which has the potential to carry out detailed analysis 'on site' in short periods of time. These chips are now very cheap to manufacture and are reusable - it isn't difficult to see them being in routine use in the fairly near future.

Friday, 26 March 2010

New biocontrol agent for Aspergillus contamination of peanuts

Contamination of peanuts by Aspergillus flavus (Wiki) is a major problem for farmers as it tends to grow in the stored crop after harvest and then cause spoilage by synthesising highly poisonous mycotoxins (aflatoxin). The use of chemical fungicides to prevent Aspergillus growing on the crop is effective but is also expensive and may not be the best solution for all groups - environmentalists for example tend to frown on allowing too many synthetic chemicals into the environment and our food chain.

This is the focus of intense research into prevention of contamination and into breeding 'aflatoxin resistant' crops for example. Several studies have used harmless bacteria and even isolates of Aspergillus itself from a variety of locations, some with very good results.

New research from China uses a novel approach to the problem and has isolated a bacterium that it considers could effectively reduce the growth of Aspergillus on peanuts. The bacterium is isolated from a novel location (the sea) in the hope that the antifungal activities it may possess will be distinct from the earlier studies - they hope to find new mechanisms to defeat Aspergillus contamination and not to repeat that which had already been studied albeit in different ways.

Marine Bacillus megaterium was used to compete with Aspergillus in laboratory experiments on stored peanuts and subsequent contamination by Aspergillus monitored. Results showed that B. megaterium inhibited growth of Aspergillus quite significantly, and also that growth media in which B. megaterium had been grown but which all the bacteria had been removed was also active. This suggests that B. megaterium is secreting an antifungal substance, possibly one that is novel and not previously known.

Watch B megaterium grow here

Monday, 22 March 2010

Basilea Teams up with Astellas to promote new antifungal

The new antifungal drug isavuconazole (made by Basilea) which is in the later stages of its testing and regulatory approval has received a significant boost  by being the subject of  a major new partnership in the drug manufacturing world.
Basilea has sold worldwide rights for the sale of isavuconazole to Astellas and this means that Astellas can take over further development and commercialisation as well as manufacturing - Astellas have a lot of experiance in the antifungal field as they already market 2 other products. This will hopefully give the prospective launch of isavuconazole new impetus and will allow Basilea to concentrate on other drugs it is developing.

Isavuconazole is in current clinical trials for the treatment of invasive aspergillosis, so assuming results are favourable may come to market in the fairly near future.

An independent data safety monitoring board recommended the continuation of the phase III clinical trial of isavuconazole for the treatment of invasive Aspergillus infections based on a futility analysis.This type of analysis is designed to detect any significant safety issues in the trial which might make it necessary to terminate the trial.

Earlier studies have suggested that it has fewer side effects compared with existing comparable antifungal drugs (e.g. voriconazole, itraconazole), so the outcome of the current clinical trials is eagerly anticipated.

Friday, 12 March 2010

Run your car on Aspergillus?

Recent online articles have highlighted the efforts underway to find alternate sources of energy, particularly for the running of engines.
In the paper mentioned (Mahmood & Hussain 2009) plant material (waste tea) is treated with a nanocatalyst at high temperatures followed by 'transesterification' yielding 40% biodeisel!

The next step featured is more relevant to this blog. Aspergillus niger is used to ferment the tea leaves in a process which was much slower than all that heating and 'transesterification' (3-5 days) BUT yielded far more biodiesel at nearly 60% of the original biomass used.

The authors conclude A. niger could be a viable producer of biodeisel and the many millions of tonnes of thrown away tea could be a very useful resource for generating that biodeisel.

Monday, 1 March 2010

The fall and rise of the healthcare mycologist

People most often associate the treatment of their health problems with the doctors and nurses who they see every time they call in to the clinic. There is no arguement with that conclusion however people often do not realise that behind that group of professionals lies another highly skilled group of people: the healthcare scientist.

Healthcare scientists are not medically qualified and so cannot treat patients directly but they are very highly skilled in one of a range of important fields (50 different fields at the last count) closely allied to the frontline of healthcare e.g. genetics, diagnostics, physical engineering, IVF specialists. As medical science advances it also gets very much more complex and thus demands more support from specialist scientists with every year that passes - there are currently 50 000 healthcare scientists working in the UK alone.

One of those scientific specialisations is medical mycology (i.e. the study of illnesses caused by fungi). Up until very recently the UK was depending on a very small group of senior mycology scientists to provide all its expert mycology advice. Professor Malcolm Richardson (based at the National Aspergillosis Centre, Manchester, UK) is one of those experts and he had noticed few new scientists coming through in this field. The existing six scientists seemed to have few candidate to replace them.

However more recently a surge in interest has been noted by Prof Richardson who trains new mycologists. Four graduates are now undergoing training at Manchester participating in a four-year programme funded by the Department of Health.
“That’s quite a change — there have been very few trainees over the last ten years,”
said Prof. Richardson.

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