A form of bacteria that lives harmlessly on cats has been used to successfully treat drug-resistant skin infections in mice. These bacteria produce antimicrobial substances that can kill off emerging pathogens and could be used as bacteriotherapies against severe animal and human skin infections.
The skin contains hundreds of different microorganisms and research from microbiome studies reveals that many of these organisms have a function with promoting skin health and with combating pathogens.
One concern with taking antibiotics or with applying antiseptics to the skin is that the natural balance of the skin community can become disrupted and this can create an imbalance, leading to a predominance of less desirable organisms. This itself can lead to problems with skin health.
To help counteract this, researchers from University of California San Diego School of Medicine have shown how the transplantation of commensal antimicrobial bacteria as a therapeutic against infections from drug-resistant bacteria can redress the imbalance.
Specifically the researchers have bene examining whether staphylococci collected from dogs and cats have antibacterial activity against a drug-resistant bacteria that causes severe skin infections.
The researchers have been seeking to identify bacteria with activity against methicillin-resistant Staphylococcus pseudintermedius, which is an emerging pathogen like MRSA. This Staphylococcus can move between species and cause severe atopic dermatitis.
To date five strains isolated from cats and dogs were found to inhibit the pathogen’s growth by 80 percent. The most promising has been isolated from cats, appropriately named Staphylococcus felis.
Researchers identified antimicrobial substances produced by S. felis active against the pathogen. By analysing the liquid that S. felis had been cultured in, small protein fragments were detectable. Of particular interest was a type of antibacterial metabolite called a micrococcin. These substances are capable of disrupting bacterial cell walls and increasing the production of toxic free radicals.
By performing experiments on mice, the researchers are considering how to develop a therapy against S. pseudintermedius. The studies to date show a reduction in scaling and redness after the treatment.
These findings suggest that a commensal bacterium from another species could be used as a bacteriotherapy as an alternative to antibiotics for hard-to-treat infections.
The research is titled “Antimicrobials from a feline commensal bacterium inhibit skin infection by drug-resistant S. pseudintermedius” and it has been published in the journal eLife.
