Novel Porphyrin Antimicrobial


Novel Porphyrin Antimicrobial



Marissa Christine Jama, Nehaben N Patel



The CDC reports there are over 2 million illnesses and 23,000 deaths per year attributed to antibiotic resistance in the US. The recent report of a colistin resistant strain of E. coli in the US heralds the first truly panresistant bacterium. These data signal a major challenge to human health and a clarion call for new and novel antibacterial treatments. Photodynamic therapy using porphyrins and light activation has emerged as one such strategy. We report here standard antimicrobial testing of a novel Zn containing porphyrin, ZnP, we recently patented (US PAT. NO. 14,466,662). Additionally, we report a novel antimicrobial strategy using a well-known porphyrin, TMP, in the treatment of biofilm associated pathogenic bacteria (US PAT. NO. 8,551,456.Our novel, patented porphyrin, (ZnP) possesses dark as well as light activated toxicity effective at micro molar levels against a broad range of bacterial pathogens: P. aeruginosa, Listeria monocytogenes, Mycobacterium smegmatis and MRSA, for example. Typical killing ranges are from 4-8 logs. Further, ZnP added to planktonic cells results in biofilms that are 6 logs reduced compared to control biofilms. We also present data that show pretreatment of 24h old P. aeruginosa biofilms with TMP, in the dark, substantially enhanced killing by antibiotics such as tobramycin and vancomycin; and dismantles the biofilm from the surface. Enhanced killing by vancomycin is of great interest since this is an antibiotic not typically effective against gram-negative bacteria. In vitro toxicity testing of ZnP has shown no toxicity at effective treatment levels in lung alveolar tissue cells. Resistance has yet to be observed by us or reported by others. Our novel porphyrin ZnP is uniquely effective against a wide range of pathogens in the absence of light. Prior to this finding the requirement for light has limited the areas in the body where porphyrins could be used to treat infections. Our finding that TMP can enhance and expand the effectiveness of currently used antibiotics, and dismantles biofilms from surfaces, provides a combination therapy that should prove to be useful for a wide range of infections.

Publication Date


Project Designation

Graduate Research - Graduate

Primary Advisor

Jayne B. Robinson

Primary Advisor's Department



Stander Symposium project

Novel Porphyrin Antimicrobial