Biomarkers for infection: enzymes, microbes, and metabolites

Abstract

Wound infection is a severe complication causing delayed healing and risks for patients. Conventional methods of diagnosis for infection involve error-prone clinical description of the wound and time-consuming microbiological tests. More reliable alternatives are still rare, except for invasive and unaffordable gold standard methods. This review discusses the diversity of new approaches for wound infection determination. There has been progress in the detection methods of microorganisms, including the assessment of the diversity of the bacterial community present in a wound, as well as in the elaboration of specific markers. Another interesting strategy involves the quantification of enzyme activities in the wound fluid secreted by the immune system as response to infection. Color-changing substrates for these enzymes consequently have been shown to allow detection of an infection in wounds in a fast and easy way. Promising results were also delivered in measuring pH changes or detecting enhanced amounts of volatile molecules in case of infection. A simple and effective infection detection tool is not yet on the market, but innovative ideas pave the way for the investigation of fast and easy point-of-care devices.

Hydrogel Dressings for Advanced Wound Management

“…Though the colour response does not provide information about the involved bacteria species, an indication of any early infection may drastically change the outcomes in the wound management. Readers are referred to excellent articles with extended registers for details on monitoring wound status based on enzyme activities related to infections 130,131 . Instead, this short review explains only the basic principles of these detection concepts and their integration in hydrogel-based dressings.…”

Biomarkers of Infection and Inflammation

“…Chronic wound infections are a growing problem worldwide and a life-threatening complication for patients. 64 Early identification of bacterial wound infections, especially in patients that do not have the classic clinical signs of inflammation and purulent secretions, can prevent progression to severe infection and/or sepsis. 65 Quantifying enzyme activity in wound fluid is being investigated as it could allow for early detection of bacterial infection.…”

“…65 Quantifying enzyme activity in wound fluid is being investigated as it could allow for early detection of bacterial infection. Two potential enzyme biomarkers are being studied; the human neutrophil elastase (HNE) and cathepsin G. 64,65 These enzymes are secreted into the wound as an immune mediated response to infection. 65 Neutrophil elastase and cathepsin G are proteases stored in neutrophil azurophilic granules that are released during inflammation and help degrade bacteria during phagocytosis.…”

“…65 Neutrophil elastase and cathepsin G are proteases stored in neutrophil azurophilic granules that are released during inflammation and help degrade bacteria during phagocytosis. 64,66 Researchers are also investigating other enzymes and proteins as possible emergent biomarkers of bacterial wound infections. 65 on August 31 2020 http://hwmaint.clsjournal.ascls.org/…”

Fast Blue RR—Siloxane Derivatized Materials Indicate Wound Infection Due to a Deep Blue Color Development

“…Hence, alternative methods based on the assessment of biomarkers like metabolites, enzymes or microbes have been suggested [4]. New point-of-care devices should facilitate the diagnosis and treatment of chronic wounds [5].…”