Just walk Away

Successful treatment of infections depends a lot on the inputs given by microbiologists and their accurate interpretation of results. The process involves plenty of hard work, as a great deal of preparation goes into getting the test ready, followed by a rapid and precise identification and detection of antibiotic resistance of the causative organism. However, the traditional manual method of biochemical identification and susceptibility testing require at least 24 hours to be readable. Since the process is lengthy and tedious, a number of errors can crop in at any stage. Further, repeat testing as well as additional testing required due to erroneous result may further delay identification and could cost patients their lives. Hence, the development of an automated microbiology system was inevitable. With the availability of research in micro computing and robotics, the idea of automated microbiology system took shape and today we have systems that automate nearly all steps in the identification and antimicrobial susceptibility testing (ID/AST) of most microrganisms. The Walkaway® 40 SI automated microbiology system from Dade Behring, USA is one of the latest machine in this segment to arrive in India. 

Walkaway® 40 SI system offers various benefits over the manual systems. The main advantage being reproducibility of the result. Further, the convenience of tracking results, the availability of results within one working day and reduced amounts of contaminated waste are also desired benefits in a microbiology set-up. Further, the software of the machine allows automatic connection to the laboratory information system, providing better data management and efficient workflow.
 
The instrumentation
 

The Walkaway® 40 SI instrument consists of a large incubator and reader unit. It is used in conjunction with microdilution panels that contain media, selected biochemicals and antibiotics in serial dilutions like conventional microdilution tubes. The other accessories with the instrument are line condotioner, turbidity meter, Dade barcode printer, LabPro Alert Software (AS) 4 and RENOK innoculator.
The device utilises the automated incubator, reader and the software to identify the biochemical reactions taking place in the wells of the panel, which is determined by colour changes, fluorescence changes, or the proportion of turbidity in the wells of the panel. Using this machine, an initial minimum inhibitory concentrations (MIC) antibiogram can also be obtained for each organism. WalkAway® 40 SI system can be used with either conventional overnight panels or rapid fluorescent identification and susceptibility panels. The small well size requires micro quantities of reagents, which again benefits the laboratory. The panels are inoculated manually using a RENOK — a multi channel inoculator, then placed in the reader incubator. All subsequent steps are fully automated. The instrument reads the bar codes to identify the type of panel and the patient identification number; it incubates the panels for the required time and robotically positions the panels for readings. The frequency of reading depends on the panel type. Once the panel is read and a result generated, it can be removed and discarded.
Time saving
 The WalkAway® 40 SI system has the potential to produce same day results on most isolates. The turnaround time of the machine — the time from placing the panel in the instrument to the availability of a final result, is less and provides rapid results for both identification and susceptibility. Interestingly, if the susceptibility is reported on time, it could translate into appropriate change in antibiotic therapy and enhance patient recovery. Further, WalkAway® 40 SI system has been used to provide reliable same-day direct blood culture results also.  
Labour advantage
 It is one of the most desired outcome of automation in the West. Yet in