It has been found by researchers in Pennsylvania and Iowa that fungal communities found in chronic wounds can create mixed bacterial bacterial-fungal biofilms and can be associated with poor outcomes and longer healing times. The first deep characterization of the fungi found in diabetic foot ulcers has been published in mBio which is an online open-access journal of the American Society for Microbiology.
The research team followed 100 patients with diabetic foot ulcers – open wounds which are found on the bottom of the foot for 26 weeks or until the wound healed or required amputation. In their findings, they found out that fungal components of the microbiome can play a major role in hampering the healing of chronic wounds.
As said by Elizabeth Grice, assistant professor of dermatology and microbiology at University of Pennsylvania in Philadelphia and senior author on the study, “Chronic wounds are a silent epidemic.” She adds: “They usually occur in conjunction with another disorder such as diabetes or obesity, but once a chronic wound occurs, it requires a lot of healthcare and has a devastating effect on a patient’s quality of life.”
It has been estimated by the American Diabetic Association that more than 7 million diabetics in the US will have a diabetic foot ulcer in their lifetime and fifteen percent will end up with a lower limb amputation. The cost for healthcare for chronic wounds in the United Stated is ten billion dollars each year.
Grice, alongside postdoctoral researcher Lindsay Kalan, wanted to know which fungal species make up the communities thriving deep inside a chronic wound and what roles they may play in impaired healing. According to Grice, this represents a huge missing piece of chronic wound research.
The same medical care was given to all of the ulcer patients. For every two weeks, A team led by Sue Gardner, professor of nursing at University of Iowa, sampled patients’ deep wound fluid. These samples were then sent to Grice and Kalan for genetic sequencing and identification of the fungi in the wounds.
The team discovered that eighty percent of the wounds have fungi, which is much higher than the previous estimates from 284 different species. Cladosporium herbarum which was the most abundant fungu, was found in forty-one percent of the samples and the human pathogen Candida albicans was next most abundant, in a little over one-fifth of the samples.
Kalan says that the study is a step towards the better understanding of chronic wounds and to find better ways of treating them. In her own words, “There are polymicrobial interactions within these wounds. It’s important to look at the fungal and bacterial communities and how they interact with each other and the immune system to impair or promote healing.”