Ceramic Filter Project Ian Nettleship, University of Pittsburgh, DMR 1043137

1. Protecting Ceramics Surfaces from MycobacteriaIan Nettleship, University of Pittsburgh, DMR 1043137 Outcome: Researchers at University of Pittsburgh have shown that nanoparticles can be used to impede mycobacteria biofilm formation on ceramic surfaces. The degree to which nanoparticles kill mycobacteria depends on the specific species. Impact: Nanoparticles could be used in point-of-use technologies such as ceramic shower head water filters to protect people with compromised immune systems from opportunistic mycobacteria pathogens found in municipal water supplies. However the nanoparticle technology will have to be tailored to the pathogens found in the specific human microenvironment (e.g. showerheads). Explanation: Waterborne bacteria including mycobacteria prefer to live in communities on the surface of materials where they can cover themselves with an extracellular matrix and develop higher resistance to biocides. Indeed a recent study has shown that mycobacteria can become concentrated in domestic showerhead biofilms. Strategies for protecting surfaces should involve functionalizing the surfaces with antibacterial compounds that will remain active on the surface for long periods of time. Antibacterial nanoparticles may offer potential in this respect by impeding biofilm formation. A electron micrograph showing the early stage of mycobacteria biofilm formation on oxidized silicon where the bacteria begin to cover themselves in extracellular matrix.

2. Effect of Silver Nanoparticles on MycobacteriaIan Nettleship, University of Pittsburgh, DMR 1043107 Silver nanoparticles are currently being used to protect the surfaces of material from the growth of microbial life. Most of the studies in the literature concern the effect of silver nanoparticles on non-pathogenic strains of cultured bacteria such as E.coli. This study evaluated the effect of silver nanoparticles on different wild type species of waterborne mycobacteria. The silver nanoparticles were found to be very effective against mycobacterium smegmatis giving a log 6 to log 7 reduction after 48 hours of exposure. Surprisingly, silver nanoparticles were much less effective against opportunistic human pathogens such as mycobacterium avium and mycobacterium marinum which gave only log 5 and log 2 reductions respectively over 48 hours. Silver nanoparticles stop mycobacterium smegmatis from growing in water. The reduction in the number of bacteria over a control sample without silver nanoparticles is between 7 and 8 orders of magnitude after 48 hours

3. Ceramic Filter ProjectIan Nettleship, University of Pittsburgh, DMR 1043137 The Ceramic Filter Project provides engineering undergraduate students with service learning opportunities and project work related to the manufacturing methods used to make ceramic water filters in low-income communities in developing countries. Filter making workshops are also organized for students and interested members of the public to learn the hands-on skills needed to make water filters using equipment similar to that used by NGO’s in the field. The workshops will continue to be hosted by the Ceramic Studio in the Braddock Carnegie Library. Dr. Nettleship is the founder of the Ceramic Filter Project at the University of Pittsburgh and the Coordinator of the Braddock Carnegie Library filter making facility. Braddock is a municipality close to the city of Pittsburgh that is 66% African American with 34% of families living below the poverty line. Photographs of a training workshop in which undergraduate and graduate students learn how to form low-cost ceramic filters with equipment similar to that used in the field.