Tag Archives: staph infections

Smart Wound Dressing

Smart Wound Dressing Emits Light When Dressing Needs to Come Off

The human skin provides a natural barrier to pathogens and serves as the first line of defense against harmful microbes. When the skin’s integrity is broken via cuts, sores, or other wounds, the site of broken skin potentially becomes an entryway for a systemic infection. Hence, good wound care is crucial from developing sepsis, or widespread infection that can lead to multi-organ failure, particularly in people with chronic diseases, e.g. diabetes, rheumatoid arthritis, or those who are immunocompromised, e.g. receiving chemotherapy, immunotherapy, battling active HIV infection.

Good wound care technique is largely dependent on the specific characteristics of the wound: nature of wound, size, amount of exudate, illness that can exacerbate wound, etc. However, one thing clinicians agree on is that the wound should be kept covered until a temporary barrier, like a scab, forms to prevent infection. Checking on status of wound healing may require frequent dressing changes, which can be detrimental to proper healing. As a result, Swiss scientists collectively from University Hospital Zurich, Centre Suisse d’Electronique et de Microtechnique (CSEM), EMPA, and ETH Zurich developed a type of smart wound dressing called Flusitex—short for fluorescence sensing integrated into medical textiles.

Flusitex works by monitoring the pH (acidity or alkalinity) of the wound. When normal healing is progressing well, pH jumps to 8 before resting around 5 or 6. If the wound’s healing trajectory deviates from standard healing protocols, or the wound becomes chronic, pH may oscillate between 7 and 8. Integrated into the smart wound dressing are pyranine and benzalkonium chloride molecules. Pyranine is a pH-sensitive fluorescent dye, which enable the dressing to fluoresce when a UV light is shined on the bandage at an internal pH of 7.5—an indication the chronic wound is on the verge of healing—which alerts clinicians to leave the dressing alone. Benzalkonium chloride, an antiseptic, is particularly known for killing Staphylococus aureas bacteria, which are commensal on the human skin and may cause opportunistic infections if allowed to enter the wound bed.

To make Flusitex more accessible and user-friendly, scientists are exploring ways to allow an app and camera from a smartphone to interpret fluorescing pH changes on the smart wound dressing so that users can monitor wound healing progress from home.

New Staph Vaccine Derived from Pathogens’ Toxins

Scientists at University of Iowa’s Carver College of Medicine have created a new staph vaccine that protects the public from Staphylococcus aureus infections by targeting toxins made by these bacteria. The toxins are responsible for symptoms people exhibit when infected with staph, such as high fever, low blood pressure, and toxic shock. The researchers suspect immunizing the population against the toxin can prevent staph-related pneumonia deaths associated with MRSA—a highly drug resistant form of Staphylococcus aureus.

In animal studies, rabbits were inoculated against three staph toxins and were unaffected even after being exposed to high doses of bacteria. In addition, the rabbits’ lungs were clear of the pathogens, protecting them from staph-related pneumonia. The team also took serum from the immunized rabbits and injected it into other animals. Protection was conferred (passive immunity) to those animals, indicating antibodies as a result of the vaccine were the factor that conveys immunity.

The scientists are hoping the new staph vaccine can protect the public from all strains of Staphylococcus aureus, including MRSA, and thus prevent serious conditions and deaths associated with the bacteria, such as pneumonia and sepsis. According to the Centers for Disease Control and Protection (CDC), staph-related infections and subsequent deaths are a major cause of disease in the United States.

In the past, staph vaccines were developed to target proteins on the surface of Staphylococcus aureus, which not only failed to effectively vaccinate the test subjects but, new studies have found, increased the acuity of staph infections.

Many healthy people in the community are colonized with staph on their skins, nose, and lungs, without acquiring an infection but can spread the bacteria to others who may be susceptible. The new staph vaccine may be the answer to preventing an infection that plagues hundreds of thousands of people in the United States each year.