New research from Tailand's Songkla University has proven that extracts from two combinations of herbs will deter the growth of a dangerous, sometimes flesh-eating bacteria species called Staphylococcus epidermidis.
The researchers tested extracts of three different herbal formulas that have been used by traditional Thai herbalists for centuries for skin conditions. Of the three formula extracts tested, two were able to inhibit the growth of biofilms of Staphylococcus epidermidis.
The fact that these herbal combinations proved able to inhibit the Staphylococcus epidermidis biofilms indicates that herbal extracts could be used to treat the type of infections proven difficult to treat by conventional medicine.
Hospital-acquired Staphylococcus epidermidis infections
Biofilms of Staphylococcus epidermidis will often infect the skin and underlying surfaces and are frequently transmitted from hospital treatment equipment such as catheters and feeding tubes. Hospital-acquired Staphylococcus epidermidis infections have thus been one of the most difficult and dangerous to treat, outside of hospital-acquired Staphylococcus aureus in the form of MRSA – the antibiotic-resistant strain.
In an three-decade old study of hospital-acquired Staphylococcus epidermidis, 80 patients who were to undergo cardiac surgery were tested for antibiotic-resistant Staphylococcus epidermidis before and after surgery. Prior to surgery, 4 of the 80 patients were found to have antibiotic-resistant Staphylococcus epidermidis on their chests. Following their surgery, 43 of the 80 patients were found to be infected by antibiotic-resistant Staphylococcus epidermidis within their chest wounds. This study indicated the extent that hospital procedures can create infections.
A more recent study from this May's Journal of Infectious Diseases found that antibiotic-resistant Staphylococcus epidermidis infections are rampant among U.S. cardiac surgery centers. In a study of four different U.S. cardiac centers, 1,559 culture tests found 565 were positive for Staphylococcus epidermidis infections and of these, 46% were from one of seven different antibiotic-resistant Staphylococcus epidermidis clones. The researchers commented: "We describe S. epidermidis clones that are highly resistant to antibiotics distributed across US cardiac centers."
Other research has found that babies born in hospitals can also contract Staphylococcus epidermidis infections.
Staphylococcus epidermidis and Necrotizing Fasciitis
As biofilms of Staphylococcus epidermidis infections develop, they can become necrotizing fasciitis. Fasciitis refers to an infection that eats away at the tissues below the skin, and necrotizing fasciitis can spread into all directions, including the epidermis layer, eating away the body's skin surfaces and internal organs by killing cells. Doctors often have to resort to amputation to remove infected regions of the body infected by necrotizing fasciitis.
Necrotizing fasciitis has sometimes been described as specific to antibiotic-resistant virulent Staphylococcus aureus (MRSA), but biofilms of Staphylococcus epidermidis and other bacteria can also cause necrotizing fasciitis. While some strains of Staphylococcus epidermidis are normal inhabitants of the skin – and protect the skin layers – other strains are more virulent and cause disease. Most of these are resistant to penicillin, tetracycline, methicillin and other antibiotics.
Herbal Treatment of Biofilms
It is this later type of Staphylococcus epidermidis that was studied, and biofilms were developed to be tested against the three herbal extracts.
The herbal extract that proved to inhibit Staphylococcus epidermidis biofilms the most was an extract of a formula containing Arrowroot (Maranta arundinacea L.), the bark of the Indian Trumpet tree (Oxylum indicum Vent.) – also called the tree of Damocles – and the whole plant parts of Tropical Spiderwort (Commelina benghalensis L.).
This blend of herbs underwent two different extraction methods – one using water and one using ethanol. The ethanol extract proved to inhibit Staphylococcus epidermidis biofilm more than the water extract.
The herbal extract prevented the growth of Staphylococcus epidermidis biofilms on glass surfaces and polystyrene surfaces. As these surfaces both provide frequent sources of infections in hospitals, it showed the researchers that the extract could prevent many hospital-acquired infections of Staphylococcus epidermidis.
In addition, the researchers tested the herbal extracts upon Staphylococcus epidermidis biofilms that they cultured for seven days. The most successful extract destroyed up to 90% of these mature Staphylococcus epidermidis biofilm cultures.
Another herbal combination tested – this one composed of an extract of Turmeric (Curcuma longa L.), Areca Palm seed (Areca catechu L.), Asian rice seed (Oryza sativa L.) and Mangosteen (Garcinia mangostana L.) – proved to inhibit biofilm growth of Staphylococcus epidermidis by 30% to 40%.
Both of the successful extracts have been utilized by traditional Thai medicine doctors for centuries as treatments for skin conditions. Modern research has confirmed that many skin conditions are related to bacteria infections.
- Chusri S, Sompetch K, Mukdee S, Jansrisewangwong S, Srichai T, Maneenoon K, Limsuwan S, Voravuthikunchai SP. Inhibition of Staphylococcus epidermidis Biofilm Formation by Traditional Thai Herbal Recipes Used for Wound Treatment. Evid Based Complement Alternat Med. 2012;2012:159797.
- Archer GL, Tenenbaum MJ. Antibiotic-resistant Staphylococcus epidermidis in patients undergoing cardiac surgery. Antimicrob Agents Chemother. 1980 Feb;17(2):269-72.
- Gordon RJ, Miragaia M, Weinberg AD, Lee CJ, Rolo J, Giacalone JC, Slaughter MS, Pappas P, Naka Y, Tector AJ, de Lencastre H, Lowy FD. Staphylococcus epidermidis colonization is highly clonal across US cardiac centers. J Infect Dis. 2012 May 1;205(9):1391-8.
- Bingöl-Koloğlu M, Yildiz RV, Alper B, Yağmurlu A, Ciftçi E, Gökçora IH, Ince E, Emiroğlu M, Dindar H. Necrotizing fasciitis in children: diagnostic and therapeutic aspects. J Pediatr Surg. 2007 Nov;42(11):1892-7.