ISU’s Cyclones Develop New Antibiotic Assay Called “CLONE ZONE”

Across the map, Small World Initiative students are devising new strategies to screen their soil bacteria for antibiotic activity. The screening process is akin to the discovery of penicillin, in which Alexander Fleming observed a zone of inhibition produced by the Penicillium mold. Yet every SWI student learns that there are many ways we can visualize scientific data. At Iowa State University, the Cyclones (the school mascot) have developed a new protocol called “CLONE ZONE,” which allows them to observe antagonistic-interactions between soil bacteria and the tester strains (safe-relatives of clinically-relevant pathogens) grown under different culture conditions. The students, led by microbiology and plant pathology lecturer Claudia Lemper, grow their isolates in patches and then plug the patch with the end of a sterile Pasteur Pipette. This produces a core infused with the secreted metabolites, analogous to a Kirby Bauer disc, which is subsequently placed on a lawn or patch of the tester strain. The tester strain is then incubated at its optimal temperature or oxygen environment and later screened for inhibition, which would indicate the presence of antibiotic activity. This protocol provides yet another creative way of visualizing zones of inhibition that resembles art, with all the rigor of science.