Finding Fungal Infections Fast

Fungal infections are rough. Once they have infected a host, they are difficult to fully cure. Because of that tenacity it is very important to identify not only that one has a fungus, but what kind of fungus it is, quickly.

Unfortunately there are a lot of problems with the diagnostics implemented in today’s medicine.  Cultures of fungi can take a long time to bring results, and even then they can be false negatives.  Diagnosing from nucleic-acid amplification can detect a fungus, but with that there are several step techniques that must be done after the amplification to present any kind of difference in some of the major fungi. If you are rich you can always go for the DNA sequencing, but that is not something that can feasibly be done for every infection. So with all of these time consuming, expensive and/or inaccurate techniques we find ourselves without an ideal set of diagnostics tools.

But we got people on that.

A new study published July 2, 2012 in PLoS One has demonstrated a new PCR Method (Polymerase-Chain Reaction High-Resolution Melting) that shows promise at not only detecting both yeasts and filamentous fungi, but also differentiating between them, as well as between some of the more relevant yeast species.

New Strategy for Rapid Diagnosis and Characterization of Fungal Infections: The Example of Corneal Scraping

According to the teams journal article, over the past thirty years there has been a large uptake in reported fungi infections. Yeasts have been more responsible for serious disease but with filamentous fungi showing up in conditions such as Keratitis.

Fungal Keratitis

Keratitis is a condition in which the cornea becomes inflamed. A study in the March 2000 issue of Ophthalmology found 88 cases of fungal keratitis at the L.V. Prasad Eye Institute in India.

Keratomycosis: clinical and microbiologic experience with dematiaceous fungi.

With this increase, as well as the different therapies that are needed for treatment,  the team felt it was important to find a less labor intensive and cheaper method than DNA sequencing of quickly identifying what fungus is causing an infection.

To accomplish this, the team took a variety of samples from isolated strains as well as, suspected infections, and suspected bacterial/viral infections. They took these samples and extracted DNA, then mixed them with specific primers diluted in MeltDoctor® HRM Master Mix (CandUn, and FungUn for yeast, and FilamUn and FungUn for filamentous suspects).  They then monitored the yields of DNA extracted and what PCR inhibitors arose.

With their method the team managed to detect and differentiate between 0.1 colony forming units/µl. The new technique even detected and characterized fungi in 7 out of 10 suspect cultures that appeared negative.

It is always good to hear of new methods being developed that show promise of helping quickly and accurately diagnosing disease agents. The faster we find our culprit, the faster we can find ways to effectively fight it.