P. acnes biofilm impacts antimicrobial agents

Dr. CoenyeJersey City, N.J. - Recent data indicates that the formation of biofilms with Propionibacterium acnes (P. acnes) may be the reason why time-tested antimicrobial agents used in acne therapy at times fall short of their therapeutic goal, fueling research to develop targeted therapies to stave off the impact of biofilms in acne vulgaris.

Biofilms are clusters of bacteria that are attached to a surface, and are embedded in a slime layer on that surface. They are produced by the bacteria and serve as a natural self-protection mechanism.

“The formation of biofilms is a natural form of behavior for bacteria, and the main consequence of biofilm formation appears to be the resistance of antimicrobial agents to effectively address a given infection such as sometimes is the case in acne lesions,” says Tom Coenye, Ph.D., professor at the Laboratory of Pharmaceutical Microbiology (LPM), Ghent University, Belgium. He spoke at the Avant Institute Winter Symposium recently.

Related: Study sheds new light on biofilms

Over the past decade, there is increasing evidence showing that the vast majority of̢۬infectious diseases in humans and animals are associated with biofilm formation. According to Dr. Coenye, evidence for the presence of biofilms in acne and their hand in the pathogenesis of the disease is predominantly derived from the ability of P. acnes to form biofilms both in vitro and in vivo on implanted medical devices.

One recent study definitively showed an increased incidence of P. acnes biofilms in acne vulgaris lesions, and demonstrated that the bacteria formed large clusters of macrocolonies/biofilms in the sebaceous follicles of acne lesions, underscoring their involvement in the development of acne vulgaris lesions (Jahns AC, Lundskog B, Ganceviciene R, et al. Br J Dermatol. 2012;167(1):50-58).

“In patients with difficult-to-treat acne lesions, I think there is definitely a possibility that biofilms play a role there. We, and others have demonstrated that if P. acnes forms biofilms, it becomes much less susceptible to antibiotics and oxidizing agents, which are frequently used in the treatment of acne,” Dr. Coenye says.

Related: Acne’s ‘good’ bacteria battles ‘bad’

Next: The search for anti-biofilm agents

Anti-biofilm agents

Searching for anti-biofilm agents has become somewhat of a holy grail in terms of novel antimicrobial agents and at present, there are no current therapies that can effectively address the P. acnes biofilm formed in acne vulgaris lesions. Although no targeted therapy against biofilms exist, in vitro laboratory studies indicate that some antibiotic agents may be more active against biofilms and their formation than others. According to Dr. Coenye, however, translating these in vitro results to an in vivo model is a challenging and daunting task.

There are two avenues of research currently being explored to more effectively address the biofilm concept in acne lesions. According to Dr. Coenye, it is suspected that part of the problem with inferior antibiotic therapy is that the antibiotics are not able to penetrate into the biofilm because the bacteria are tightly packed into a cluster. Therefore, one treatment strategy against biofilms is to combine an antimicrobial with another agent that would disperse the biofilm, which in turn would drastically increase the efficacy of the antibiotic.

Also, as the bacteria inside a biofilm are known to communicate with each other and exchange signaling molecules important in biofilm formation, Dr. Coenye says another potential treatment strategy would be to develop an agent that could interfere with that communication and weaken the biofilm, rendering them more susceptible to antibiotics.

“I believe that in skin diseases and other diseases of the body that do not respond well to standard and proven therapy, it could be useful to consider that biofilms are involved in that treatment failure,” he says. “Unfortunately, however, until effective anti-biofilm agents become available, physicians are left with a trial and error approach with the currently available anti-microbial regimens.”

Disclosures: Dr. Coenye reports no relevant financial interests.

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