Recognition of anaerobic bacterial isolates in vitro using electronic nose technology

Aims: Use of an electronic nose (e.nose) system to differentiation between anaerobic bacteria grown in vitro on agar media. Methods and Results: Cultures of Clostridium spp. (14 strains) and Bacteroides fragilis (12 strains) were grown on blood agar plates and incubated in sampling bags for 30 min before head space analysis of the volatiles. Qualitative analyses of the volatile production patterns was carried out using an e.nose system with 14 conducting polymer sensors. Using data analysis techniques such as principal components analysis (PCA), genetic algorithms and neural networks it was possible to differentiate between agar blanks and individual species which accounted for all the data. A total of eight unknowns were correctly discriminated into the bacterial groups. Conclusions: This is the first report of in vitro complex volatile pattern recognition and differentiation of anaerobic pathogens. Significance and Impact of the Study: These results suggest the potential for application of e.nose technology in early diagnosis of microbial pathogens of medical importance.