30 August 2022

Double agents fight bacteria

Clinical

Researchers have found a combination of betadine and silver colloidal gel is better at eliminating bacteria and the growth of biofilms.


Betadine as well as silver colloidal gel is more effective than either substance alone for inhibiting the infection-causing bacteria, a new study shows.

And the researchers, whose work has been published in the American Journal of Infection Control, believe their findings could help medical professionals better treat and prevent serious infections in large wounds, including burns.

“Despite substantial advancements in wound treatment and supportive care, wound infections remain a serious problem, particularly in the case of large burns,” US study authors wrote.

“Our study is the first to systematically evaluate the use of betadine alone as compared to the combination of betadine and silver colloidal gel to eliminate bacteria and the growth of biofilms.”

Large wounds such as serious burns are vulnerable to microbial invasion and the production of biofilms, microbial colonies that can become attached to a wound surface and delay or prevent healing, they said.

While the topical antiseptic betadine with its broad spectrum of antimicrobial activity is widely used in the treatment and prevention of wound infections, many studies have suggested it is ineffective against some bacteria.

Topical antimicrobial dressings, including those containing silver, have long been used to support treatment and prevention of wound infections, and seem to provide a different microbial killing mechanism than betadine, the authors wrote.

The researchers measured the effectiveness of 5% betadine solution alone, silver colloidal gel (Ag-gel) alone, and the combination of 5% betadine and Ag-gel for inhibiting the growth of five strains of bacteria, including Staphylococcus aureus and Pseudomonas aeruginosa.

These are the predominant infective organisms in the clinically significant microbiome of large, acute burns, as well as clinical isolates of Klebsiella pneumoniaeStaphylococcus epidermidis and methicillin-resistant staphylococcus aureus (MRSA).

Results showed the combination of 5% betadine and Ag-gel provided complete (100%) inhibition of all five bacterial strains tested; while 5% betadine alone showed little or no inhibition of P. aeruginosa, and at best approximately 90 % inhibition of the other four bacterial strains tested.

Ag-gel alone inhibited 100% of bacterial growth among all bacterial strains except K. pneumoniae.

Notably, while 5% betadine alone killed only about 90% of K. pneumoniae, betadine and Ag-gel combined killed 100%, reinforcing the researchers’ assertion that betadine works by a different bacterial killing mechanism than Ag-gel.

“This study demonstrated that while the individual treatments using either 5% betadine solution and Ag-gel alone were ineffective antimicrobial agents, the combination of 5% betadine solution and Ag-gel was superior at eliminating all tested bacteria, including K. pneumoniae,” the authors concluded.