Abstract:
Rapid identification and enumeration of bacteria are critical, given the surge of antibiotic-resistance, global exchange of food products, and
the use of bacteria for bioremediation, pharmaceutical, and food production. In response, a wide range of methods are being developed
that can be broadly classified as nucleic acid-based, structure-based, mass spectrometry-based, and optically based. Optical methods have
generated interest given the potential for rapid, non-destructive, high-throughput, and amplification-free measurements that require minimal
sample preparation. This Perspective reviews optical methods, which are applied to identification, enumeration, and greater understanding of
bacteria routinely and more importantly at the cutting edge of research, with the aim of identifying gaps and opportunities for development.
We have focused primarily on methods that directly measure bacteria and not their effect on the sample matrix or sensing, which requires a
biorecognition element (i.e., label specific to some component of the bacterium). We identify gaps in the existing techniques and avenues for
innovation. Finally, we suggest the parameters that should be considered and recorded when reporting the development of existing and new
methods for bacterial characterization. This Perspective is intended for physicists interested in developing new optical methods for the study
of bacteria and microbiologists in need of an optical technique for bacterial applications.
