Firmocidin Puts Big Hurt on MRSA

RALEIGH, N.C. – A novel small-molecule antibiotic produced by Staphylococcus epidermidis and dubbed "firmocidin" shows early promise as a potential treatment for methicillin-resistant S. aureus and other major skin pathogens, Dr. Teruaki Nakatsuji reported at the annual meeting of the Society for Investigative Dermatology.

S. epidermidis is a commensal microorganism that appears to act as "an antimicrobial shield" in healthy human skin, protecting against some of the major cutaneous bacterial pathogens. It accomplishes this by producing firmocidin, explained Dr. Nakatsuji of the University of California, San Diego.

He and his coworkers in the laboratory of Dr. Richard L. Gallo, professor of medicine and pediatrics and chief of the division of dermatology at the university, discovered the antibiotic by screening clinical isolates of S. epidermidis and identifying strains possessing pronounced antimicrobial activity. Next, they zeroed in on the antibiotic component. Using mass spectrometry and nuclear magnetic resonance spectrometry, they determined that the structure of the purified product didn’t match that of any known molecule. They named it firmocidin.

In in vitro studies, firmocidin effectively killed S. aureus, both group A and B streptococcus, and methicillin-resistant S. aureus. In these cell culture assays, firmocidin’s antimicrobial activity was stronger than that of benzoyl peroxide.

Importantly, however, firmocidin’s antibiotic activity was selective. It didn’t affect the growth of S. epidermidis or other commensal bacteria, nor did it affect human keratinocytes or sebocytes. Thus, it could potentially maintain a normal microbiome while inhibiting bacterial pathogens. Its mechanism of action involves inhibition of DNA synthesis by interfering with A-T base pair matching, he continued.

The University of California has applied for patent protection for firmocidin and has announced it is seeking business partners for its commercialization. Possibilities include its development as an antiseptic or a topical or systemic antibiotic for treatment of skin infections that does not disrupt the healthy skin microflora.

Dr. Nakatsuji reported having no financial conflicts.

RALEIGH, N.C. – A novel small-molecule antibiotic produced by Staphylococcus epidermidis and dubbed "firmocidin" shows early promise as a potential treatment for methicillin-resistant S. aureus and other major skin pathogens, Dr. Teruaki Nakatsuji reported at the annual meeting of the Society for Investigative Dermatology.

S. epidermidis is a commensal microorganism that appears to act as "an antimicrobial shield" in healthy human skin, protecting against some of the major cutaneous bacterial pathogens. It accomplishes this by producing firmocidin, explained Dr. Nakatsuji of the University of California, San Diego.

He and his coworkers in the laboratory of Dr. Richard L. Gallo, professor of medicine and pediatrics and chief of the division of dermatology at the university, discovered the antibiotic by screening clinical isolates of S. epidermidis and identifying strains possessing pronounced antimicrobial activity. Next, they zeroed in on the antibiotic component. Using mass spectrometry and nuclear magnetic resonance spectrometry, they determined that the structure of the purified product didn’t match that of any known molecule. They named it firmocidin.

In in vitro studies, firmocidin effectively killed S. aureus, both group A and B streptococcus, and methicillin-resistant S. aureus. In these cell culture assays, firmocidin’s antimicrobial activity was stronger than that of benzoyl peroxide.

Importantly, however, firmocidin’s antibiotic activity was selective. It didn’t affect the growth of S. epidermidis or other commensal bacteria, nor did it affect human keratinocytes or sebocytes. Thus, it could potentially maintain a normal microbiome while inhibiting bacterial pathogens. Its mechanism of action involves inhibition of DNA synthesis by interfering with A-T base pair matching, he continued.

The University of California has applied for patent protection for firmocidin and has announced it is seeking business partners for its commercialization. Possibilities include its development as an antiseptic or a topical or systemic antibiotic for treatment of skin infections that does not disrupt the healthy skin microflora.

Dr. Nakatsuji reported having no financial conflicts.

RALEIGH, N.C. – A novel small-molecule antibiotic produced by Staphylococcus epidermidis and dubbed "firmocidin" shows early promise as a potential treatment for methicillin-resistant S. aureus and other major skin pathogens, Dr. Teruaki Nakatsuji reported at the annual meeting of the Society for Investigative Dermatology.

S. epidermidis is a commensal microorganism that appears to act as "an antimicrobial shield" in healthy human skin, protecting against some of the major cutaneous bacterial pathogens. It accomplishes this by producing firmocidin, explained Dr. Nakatsuji of the University of California, San Diego.

He and his coworkers in the laboratory of Dr. Richard L. Gallo, professor of medicine and pediatrics and chief of the division of dermatology at the university, discovered the antibiotic by screening clinical isolates of S. epidermidis and identifying strains possessing pronounced antimicrobial activity. Next, they zeroed in on the antibiotic component. Using mass spectrometry and nuclear magnetic resonance spectrometry, they determined that the structure of the purified product didn’t match that of any known molecule. They named it firmocidin.

In in vitro studies, firmocidin effectively killed S. aureus, both group A and B streptococcus, and methicillin-resistant S. aureus. In these cell culture assays, firmocidin’s antimicrobial activity was stronger than that of benzoyl peroxide.

Importantly, however, firmocidin’s antibiotic activity was selective. It didn’t affect the growth of S. epidermidis or other commensal bacteria, nor did it affect human keratinocytes or sebocytes. Thus, it could potentially maintain a normal microbiome while inhibiting bacterial pathogens. Its mechanism of action involves inhibition of DNA synthesis by interfering with A-T base pair matching, he continued.

The University of California has applied for patent protection for firmocidin and has announced it is seeking business partners for its commercialization. Possibilities include its development as an antiseptic or a topical or systemic antibiotic for treatment of skin infections that does not disrupt the healthy skin microflora.

Dr. Nakatsuji reported having no financial conflicts.