A sheep biofilm model of sinusitis has been developed by researchers. A biofilm is a thin layer of microorganisms, such as bacteria, that can form on a wide variety of materials, including human tissue.
When a biofilm forms on an infection, treatment becomes very complicated, since the bacteria inside it exists in a state that renders it largely immune to antibiotics. Now that bacterial resistance to many antibiotics is growing sharply, such problems are even more of a threat to patients'' health.
Emeryville, CA-based NovaBay Pharmaceuticals has been investigating ways of eliminating the biofilms created by various types of bacteria. Its chief weapon in this battle is the company''s lead compound, known as NVC-422. A member of a non-antibiotic, anti-infective class of substances called Aganocide compounds, NVC-422 has been shown to exhibit efficacy against biofilms in a series of clinical studies.
The latest evidence for NVC-422''s power against biofilms comes from a just-published study by researchers at the University of Adelaide in Australia. The study focused on sinusitis, an ailment marked by an inflammation of the paranasal sinuses, often as a consequence of a bacterial infection. Infections with the formation of a bacterial biofilm account for many cases of antibiotic-resistant chronic sinusitis. In fact, a bacterial biofilm is detected in 75% of patients undergoing surgery for chronic sinusitis.
This model provides a system to test novel biofilm treatments under in vivo conditions, preserving the dynamic interactions between the bacterial biofilm and the host. As part of the study, a set of four sheep had their sinus drainage pathways blocked and inoculated with the bacterium S. aureus, resulting in the formation of a biofilm over the course of seven days. Then the blockage was removed, and the sheep were treated with four different substances: normal saline; an Acetate/saline mix; an Acetate/saline mix including 0.1% NVC-422; and an Acetate/saline mix including 0.5% NVC-422. The sheep were later euthanized and their sinus mucosa removed for analysis of the biofilm.
The researchers determined that the NVC-422-at a concentration of 0.5%, and, to a lesser degree, at 0.1%-was effective in reducing the S. aureus biofilm mass. The reduction was statistically significant compared to the use of normal saline and the Acetate/saline mix.
"After only two treatments, the NVC-422 used in this study was observed to reduce bacterial biofilm mass in a dose-dependent manner," said Ron Najafi, CEO of NovaBay. "Further research will clarify our understanding of NVC-422''s specific abilities to reduce the incidence of biofilms, and its possible use in treating humans with antibiotic-resistant chronic sinusitis."