Experimental use of a new surface acoustic wave sensor for the rapid identification of bacteria and yeasts

Aims: Use of an electronic nose (zNose(TM)) to discriminate between volatile organic molecules delivered during bacterial/fungal growth on agar and in broth media. Methods and Results: Cultures of bacteria (Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli) and yeasts (two Candida albicans strains) were grown on agar and in broth media and incubated for 24 h at 37 degrees C. Headspace samples from microbial cultures were analysed by the zNose(TM), a fast gas chromatography-surface acoustic wave detector. Olfactory images of volatile production patterns were observed to be different for the various species tested after 24 h. Moreover, some strains (two K. pneumoniae, two C. albicans) did not show changes in volatile production patterns within our species. Conclusions: Our experiments demonstrate that the electronic nose system can recognize volatile production patterns of pathogens at species level. Significance and Impact of the Study: Our results, although preliminary, promise exciting challenges for microbial diagnostics.