Robotic Antimicrobial Susceptibility Platform (RASP): A Next Generation Approach to One-Health Surveillance of Antimicrobial Resistance

Abstract

Background: Surveillance of antimicrobial resistance (AMR) is critical to reducing its wide-reaching impact. Its reliance on sample size invites solutions to longstanding constraints regarding scalability. A robotic platform (RASP) was developed for high-throughput AMR surveillance in accordance with internationally recognised standards (CLSI and ISO 20776-1:2019) and validated through a series of experiments. Methods: Experiment A compared RASPs ability to achieve consistent MICs to that of a human technician across eight replicates for four E. coli isolates. Experiment B assessed RASPs agreement with human performed MICs across 91 E. coli isolates with a diverse range of AMR profiles. Additionally, to demonstrate its real-world applicability, the RASP workflow was then applied to five faecal samples where a minimum of 47 E. coli per animal (239 total) were evaluated using an AMR indexing framework. Results: For each drug-rater-isolate combination in experiment A, there was a clear consensus of the MIC and deviation from the consensus remained within one doubling-dilution (the exception being gentamicin at two dilutions). Experiment B revealed a concordance correlation coefficient of 0.9670 (95%CI: 0.9670 - 0.9670) between the robot and human performed MICs. RASPs application to the five faecal samples highlighted the intra-animal diversity of gut commensal E. coli, identifying between five and nine unique isolate AMR phenotypes per sample. Conclusions: While adhering to internationally accepted guidelines, RASP was superior in throughput, cost and data resolution when compared to an experienced human technician. Integration of robotics platforms in the microbiology laboratory is a necessary advancement for future One-Health AMR endeavours.

Proximity to human settlement is directly related to carriage of critically important antimicrobial-resistant Escherichia coli and Klebsiella pneumoniae in Silver Gulls

“…Minimum inhibitory concentrations (MIC) for antimicrobials were determined for the 29 K. pneumoniae and 98 CIA-R E. coli isolates recovered from the selective plates. Broth micro-dilution was performed using the Robotic Antimicrobial Susceptibility Platform (RASP) 14 as per Clinical Laboratory Standards Institute (CLSI) guidelines, with recommended breakpoints for interpreting phenotypic antimicrobial resistance being applied. 15 In addition to ciprofloxacin and ceftriaxone, the panel included antimicrobials of low and high importance for public health including ampicillin, gentamicin, sulfamethoxazole/ trimethoprim, and tetracycline.…”

Escherichia coliisolated from commercial layer hens in Australia remain susceptible to critically important antimicrobials

“…The susceptibility of the isolates to antimicrobials was determined by broth microdilution according to the Clinical and Laboratory Standards Institute (CLSI) ISO 20776 standards (18). Drug panels were prepared in-house using a customised Freedom EVO genomics platform (19).…”