Peptides to Conquer Antibiotic-Resistant Bacteria

Antimicrobial peptides called lantibiotics that have shown the ability to kill a broad spectrum of disease-causing bacteria are being genetically engineered to create new, powerful antibiotics. Special targets are bacteria that are resistant to existing antibiotics.

A new lantibiotic, called sublancin and discovered by Dr. J. Norman Hansen of the department of chemistry and biochemistry at the University of Maryland (College Park, USA), has been licensed to Antex Biologics Inc. (Gaithersburg, MD, USA). The company has also licensed another lantibiotic, subtilin 168, from the university along with a new method for producing a stable formulation. Subtilin has potent antibiotic activity but until now was too unstable to be useful as an antimicrobial. The new method yields a very stable form of subtilin 168. Antex is developing new classes of antibiotic compounds, both broad-spectrum and organism-specific.

The new lantibiotics have been shown to kill a wide range of bacteria, including the major drug-resistant nosocomial pathogens: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), Streptococcus, Pseudomonas, Escherichia coli, and Klebsiella. Lantibiotics are peptides naturally produced by harmless bacteria as part of their natural defense system to protect against other pathogenic bacteria. One of these, nisin, has been used for decades as a food preservative to prevent the growth of food-borne pathogens such as the one that causes botulism. However, lantibiotics are very safe in humans.

"Bacterial antibiotic resistance is a major unmet medical need,” said Larry Ellingsworth, Ph.D., vice president, research and development, at Antex. "We are pleased to have established a collaboration with Dr. Hansen, who is clearly a leader in the field of lantibiotics.”