The inhibitory properties of various sponges on Listeria spp.

Various retail and environmental sponges were tested for inhibitory properties against Listeria species and several other bacterial genera. Sterile sponges, unrinsed and rinsed in sterile distilled water or sterile neutralizing buffer, were placed on seeded plates of tryptic soy agar with 0.6% yeast extract. Plates were incubated at 30 degrees C for 24 h and zones of inhibition measured. The Systems Plus environmental sponge and the Technical Service Consultants Ltd sponge (sTc) proved to be the only sponges which consistently demonstrated no inhibitory properties. Results using scanning electron microscopy showed considerable bacterial attachment to the Systems Plus sponge, further corroborating these findings.