Searching for antibiotic producing soil isolates Aaron Rosenbloom Snow, Scott Chimileski, Karen N. Pelletreau University of Connecticut, Department of Molecular and Cell Biology, Storrs, Connecticut Purpose: As bacterial resistance increases and antibiotic discovery slows, there is an increasing need for new antibiotics. The purpose of this experiment was to isolate antibiotic producing soil species to potentially discover new classes of antibiotics and test its efficacy against todays most relevant pathogens. Bacillus subtilis Isolation and identification: Soil was diluted onto 10% Tryptic soy agar (TSA) to calculate CFU/g (3.3x 105) [1]. Isolates were picked from these dilutions and patched onto spread plates of the safe ESKAPEs. Plates were incubated for 2 days at 27°C and checked for zones of inhibition [2]. Lysobacter antibioticus was determined to produce the most ZOIs and was put through polymerase chain reaction (PCR). A 1392R primer of the 16S gene was used for the PCR reaction. Electrophoresis was run on the PCR products to determine quality of products, and they were sent for sequencing. Sequences were compared to BLAST sequence data from the NCBI and RDP databases to determine genus and species [3]. Antibiotic tests : An ethyl acetate extraction was done on Lysobacter antibioticus to isolate the antibiotic compound [4]. This extract was plated under a soft agar plate (liquid agar overlay of ESKAPE relative) containing B. subtilis to test if the extract contained the antibiotic. The Eukaryotic specie, Candita albicans, was grown in the presence of this extract to test its toxicity [5]. Methods: Funding: ASM Helmsley HHMI UCONN Pilot: SWI Yale UCONN [1] [2] [3] [4] [5] Characteristics of Lysobacter antibioticus: Collected January 28th 2014 Storrs, CT from 1 to 3 cm deep mud under a thawed section of a stream. Lysobacter antibioticus was isolated from a plate of 10% TSA after plating the soil sample. Tests were performed to characterize the isolate. Sequence data determined that the species was Lysobacter antibioticus with a 99% match in the database from NCBI’s 16S rRNA and the Ribosomal Database Project. Left: Ethyl acetate Extract vs B. subtilis Right: Lysobacter Antibioticus colonies Antibiotic activity of Lysobacter antibioticus: Lysobacter antibioticus produced zones of inhibition against five of eight safe ESKAPE pathogens .All zones of inhibition completely prevented growth, rather than slowing it. Lysobacter antibioticus inhibited both Gram-positive and Gram-negative bacteria. 5/8 (62.5%) safe ESKAPE species were inhibited by the antibiotics being produced. Lysobacter antibioticus is known to produce β – lactams, macrocyclic lactams, and katanosins. These inhibit both Gram-positive and Gram-negative bacteria. Results: Candita albicans was not inhibited by Lysobacter antibioticus or the ethyl acetate extract. C. albicans vs Lysobacter antibioticus C. Albicans vs Ethyl acetate extract Acknowledgements: University of Connecticut Department of Molecular and Cell Biology, Yale Center for Scientific Teaching, Helmsley Charitable Trust, Davis Educational Foundation, HHMI