A SLIC answer to a continuing problem

The burden of Anti-Microbial Resistance (AMR) is a growing problem globally. Here we present a device that determines susceptibility rapidly from primary human or animal samples and could turn the tide of AMR. SLIC (Scattered Light Integrating Collector) is a sensitive device for the detection of microbes based on the scattering of laser light.

Proof of concept studies were carried out initially to establish the lower limit of detection. This was found to be 10–50 c.f.u. ml−1. This exquisite sensitivity allowed us to commence work establishing rapid MICs. Starting with an inoculum of 105/ml bacteria and using a relevant range of antibiotic concentrations the MIC can be established in less than one microbial doubling period.

The rapid and sensitive detection SLIC affords allows for fast growing organisms such as E. coli and S. aureus to have their MICs established in less than 10 min, for any antibiotic. For slow growing organisms such as M. bovis we are able to establish an MIC in H. influenzae and Mycoplasma spp.

As bacterial quantification is continuously monitored we are able to see the action of antibiotics in real time. Using this facility, we can readily distinguish between lytic antibiotics and bactericidal but non-lytic antibiotics. This provides the opportunity to gain new insights into the mechanisms of action and the effect antibiotics have on microbes in a new way in a novel Point-of-Care device.