High-Throughput Screen for Novel Antimicrobials using a Whole Animal Infection Model

The nematode Coenorhabditis elegons is a unique whole animal model system for identifying small molecules with in vivo anti-infective properties. C elegons can be infected with a broad range of human pathogens, including Enterococcus faecalis, an important human nosocomial pathogen. Here, we describe an automated, high-throughput screen of 37,200 compounds and natural product extracts for those that enhance survival of C elegans infected with E faecalis. Using a robot to dispense live, infected animals into 384-well plates and automated microscopy and image analysis, we identified 28 compounds and extracts not previously reported to have antimicrobial properties, including six structural classes that cure infected C elegons animals but do not affect the growth of the pathogen in vitro, thus acting by a mechanism of action distinct from antibiotics currently in clinical use.