Background: Colibrí™ (Copan) is a system which automatizes the picking of isolated colonies grown on petri dishes and allows the preparation of Maldi-tof targets for bacterial identification, microbial suspensions for antimicrobial susceptibility testing, and inoculation of purity plates.
Materials/methods: A total of 239 urine specimens were inoculated onto CHROMID®CPS elite (bioMérieux) and processed into the WASPLab® system. Isolated colonies of E. coli (n=165), Enterococcus spp. (n=42) and Staphylococcus spp. (n=32) were selected by a technician on the image. Plates were transferred to the Colibrí™ for the colony picking and the automated preparation of the bacterial suspension for the realization of the VITEK2® susceptibility cards with respectively ASTN340 card for E. coli, AST-P606 for Enterococcus spp. and AST-P631 for Staphylococcus spp. In parallel, a microbial suspension was realized manually with the same plate using the procedure of the laboratory. Results were compared in term of Essential Agreement (EA) and Categorical Agreement (CA) globally for the card and individually per antibiotic. Acceptance criteria used for the comparison were based on ISO 20776-2.
Results: For the EA, a total of 2796 MIC (Minimum Inhibitory Concentration) for E. coli, 380 for Enterococcus spp. and 570 for Staphylococcus spp. were compared to the manual methodology. The global EA was respectively 99.7%, 100% and 99.3%. The individual EA varied from 93.8% to 100% for other antibiotic/species. Concerning the CA, among a total of 2781 data for E. coli, 376 for Enterococcus spp. and 545 for Staphylococcus spp., the global CA varied from 98.4% to 99.1% with an individual CA from 95.2% to 100%.
Conclusions: The performance of Colibrí™ for the automated preparation of bacterial suspensions are equivalent to the manual procedure for the realization of VITEK® 2 susceptibility cards for E. coli, Enterococcus spp. and Staphylococcus spp. Colibrí™ allows the total automation of urine specimens from the sampling to the results of VITEK®2 antimicrobial susceptibility testing. The introduction of Colibrí™ in the workflow of a laboratory allowed a consequent gain in reproducibility, productivity and traceability with a real medical added value for the patient.