Identifying the characteristics of bacterial species can improve treatment outcomes and mass spectrometry methods have been shown to
be capable of identifying biomarkers of bacterial species. This study is
the first to use volatile atmospheric pressure chemical ionisation mass
spectrometry to directly and non-invasively analyse the headspace of
E. coli and S. aureus bacterial cultures, enabling major biological
classification at species level (Gram negative/positive respectively).
Four different protocols were used to collect data, three utilising
discrete 5 min samples taken between 2 and 96 h after inoculation and
one method employing 24 h continuous sampling. Characteristic
marker ions were found for both E. coli and S. aureus. A model to
distinguish between sample types was able to correctly identify the
bacteria samples after sufficient growth (24–48 h), with similar results
obtained across different sampling methods. This demonstrates that
this is a robust method to analyse and classify bacterial cultures
accurately and within a relevant time frame, offering a promising
technique for both clinical and research application