Fungal Terrorists

Slide of an infected turkey brain

Slide of an Aspergillus infected turkey brain (Photo credit: Wikipedia)

Jenna Rae Shearer (11 AM Micro) enjoyed looking at the different kinds of molds in lab before Thanksgiving, but we didn’t get a lot of time to talk about the diseases they can cause. A good rule of thumb to remember is that although fungi do not typically cause serious disease in humans who are in generally good health, pretty much any fungus is capable of causing fatal disease in the right conditions. Here is Jenna’s summary about two fungi that can cause deep tissue damage.

Claiming six soldiers’ lives, a fungal infection is embedding itself deep into soldiers’ wounds and doing damage. The funguses responsible for the infections are found in the soil of Afghanistan. It is believed that when a soldier suffered from an IED or an explosive attack of sorts, the soil is blasted into the open wound where it has easily past the first barrier of defense – our skin. The infections are severely complicating what are already difficult war wounds. The fungi responsible for the deaths and infections are Mucor and Aspergillus terreus (Zoroya, 2012).

Mucor is a Zygomycota. They have aseptate hyphae, no rhyzoids, grows best at less than 37 degrees Celsius  contain sporangiophores, have spores, long fibers, and have nuclei all along their hyphae (Doctor Fungus, 2007). Mucor typically affects immunosuppressed people and treating the infections it causes proves difficult. A major trait of Mucor is that fact that it invades vascular tissue which usually leads to morality. If invasion of this fungus isn’t caught early, there typically is a not so good prognosis. Once the vascular system is invaded, necrosis of the skin tissue occurs along with perineural invasion (Doctor Fungus, 2007). Surgical amputation of the affected areas is usually conducted to try and save the rest of the skin, but sometimes it doesn’t work the first time and a second amputation needs to be made. Also, aggressive treatment of antibiotics is utilized to try and fight the infection. For Mucor, a cocktail of antibiotics is used but Amphotericin B is one of the key players.

Aspergillus terreus on the other hand is resistant to Amphotericin B. It is Ascomycota. There is presence of septate hyphae and conidiophores. This fungus can infect cutaneously but typically cause pulmonary infections after the fungal spores have been inhaled. Mucor caused necrosis, so having a cutaneous infection from Aspergillus terreus kind of tag teams the infection. It makes it even more difficult when one microorganism is resistant to the other ones treatment. The pulmonary infections cause systemic affects and have a rather high mortality rate (Baddley, Pappas, Smith, & Moser, 2003). Caspofungin and posaconazole are found to be effective against the fungal infection, yet once again the infection needs to be caught early enough for better chances of survival.

It is a scary thing what is happening to these soldiers. Not only are they risking their lives daily, but they are becoming wounded with unimaginable injuries. On top of it, these fungi are invading and infecting their already traumatized bodies. Some cases the soldiers should heal fine, others they should recover fine with the exception of having the injured body part amputated. However, when Mucor and Aspergillus terreus come into the picture, these soldiers are being infected with spores systemically and have to battle death (the chances aren’t usually good!). The doctors could have the soldiers take antibiotics to premeditate the occurrence of acquiring these harsh infections, yet at the same time being on antibiotics for a long time is a bad thing. Possibly, when the soldier is injured in a blast or due to an IED where this contaminated soil could be penetrating their skin, they could begin taking the antibiotic cocktail as a precautionary. Hopefully our troops will soon have a solution and not have to fear these fungal terrorists along with the real ones.

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About ycpmicro

My name is David Singleton, and I am an Associate Professor of Microbiology at York College of Pennsylvania. My main course is BIO230, a course taken by allied-health students at YCP. Views on this site are my own.

Posted on November 28, 2012, in Guest Post, Microbes in the News. Bookmark the permalink. 2 Comments.

  1. It is really scary what is our soldiers have to go through.My brother is active duty for the national guard and when he was overseas for two years, a fungal infection or anything of that nature wasn’t a concern that I had even thought of. It is however, a major concern and more attention should be brought to this concern. I was reading an article pertaining to this topic which mentioned: “Among 2413 U.S. soldiers in Afghanistan with severe traumatic injuries between June 2009 and December 2010, 37 developed (invasive fungal infections) IFIs, most often from blast injuries sustained during foot patrol.” – http://infectious-diseases.jwatch.org/cgi/content/full/2012/1121/3

    • Fungal infections acquired from the environment are not a very big concern, for the broad population in general. Innate defenses are usually pretty good at protecting us, and most serious fungal infections in the US are in otherwise immunocompromised individuals. Trauma such as the kind outlined by Jenna offers an entry point for fungal spores, plus the fact that the dry environment in the Middle East allows the survival of these rather tough cells, leads to a high incidence of fungal infections in injured servicemen and women.

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