Nosocomial infections are of great cost toward the individual and healthcare system. Resistance towards antimicrobial agents remains an ongoing issue. While there are various routes of transmission from respiratory pneumonia to urinary tract infection, Catheter Related Bloodstream Infections (CRBSI) are among the can cause significant morbidity. CRBSI from long indwelling catheters are often a result of the patient's skin flora invading the catheter. Standards of medical practice include antimicrobial scrubs (betadine, chlorhexidine), however the incidence of infection remains high and these result in allergy. We propose cold atmospheric plasma (CAP) has a potential alternative to traditional scrubs during installation and maintenance of the catheter. Plasma, the 4th state of matter, ionizes atmospheric gas which generates reactive oxygen and nitrogen species that have bactericidal effects. In this study we investigated the antibacterial efficacy of CAP and safety on known materials (PVC). According to Terraplasma, Utilizing the Plasmacare device for more than 6 min in a treatment session is not recommended in Humans. Step 1: We exposed ampicillin resistant E coli to plasma at a time interval of 30 second, 1 min, 2 min, 3 min. We found that even at 30 seconds the CAP was able to significantly reduce the bacterial colonization over a 24-hour incubation period. Step 2: After comparable results to Betadine, we investigated the safety of CAP to butterfly catheters over a time period of 9 min. Through qualitative and microscopic analysis, we found that even at 150% of the maximum recommended daily exposure there was no significant damage. The goal of this study is to lay foundational work for eventual human trials involving CAP in the United States. CAP is intended for topical application; we identified pig ear skin as an adequate ex vivo model for human skin. In further steps, we plan to investigate two-pronged approaches: in the pig ear skin ex vivo model: 1) investigate the safety of CAP exposure on indwelling catheter via histological staining and 2) evaluate the efficacy of CAP on live skin flora via bacterial culture.

Acknowledgements: Meharry Medical College, Stanford University School of Medicine, Department of Radiology, TerraPlasma and plasma care®