Microbiology in a box

With the ever increasing need to reduce costs and respond to Government initiatives and infection control issues relating to emerging resistance, as exemplified by Methicillin resistant Staphylococcus aureus (MRSA) and Extended Spectrum Beta Lactamase producers (ESBLs), microbiology laboratories are coming under continued pressure to review the way they work.

AT present, traditional methods of culturing and isolating primary specimens cannot be replaced and these will continue, utilising the expertise of the laboratory scientists who have undergone significant training. However, new approaches, including full automation options, are now being seriously considered for identification and antimicrobial susceptibility profiling of primary isolates. This is because traditional biochemical identification procedures, micro broth culture and disk diffusion testing all lend themselves to automation. When coupled with intelligent software and alert rules linked to the hospital information system, laboratories can automate over 90% of this routine work, as well as provide an accurate reporting system to physicians and infection control departments. This creates scope for cost savings in busy hospitals, especially in pharmacy where inappropriate or inadequate usage of antibiotics can be significantly reduced.

The MicroScan system from Dade Behring combines the traditional methodologies of biochemical isolate identification with direct growth-based antimicrobial sensitivity in one convenient, highly flexible solution. Whilst the system automates all the required steps, it allows the microbiologist to retain control over the process and to use his or her skills to resolve issues such as difficult reactions or interpretations of sensitivity/resistance. At all times, the microbiologist is able to access the processing and check the ID and susceptibility tests. As a result they can make their own informed judgements on the results and override the system’s software if deemed appropriate – an option not often available in black box, fully closed systems.

The requirement to ‘zero in’ on emerging resistance is more important than ever before, as Trusts have been charged with reducing MRSA infections by 50% by April 2008. As organisms are constantly adapting and changing, the MicroScan family of products can help laboratories meet this challenge by providing optimal detection of emerging resistance using direct, growth-based MIC testing. This methodology can be extended to allow for the true expression of resistance. Since this approach does not rely on empirical or projected answers, it remains accurate even when the unexpected is encountered. Through continuous development and innovation, such as the introduction of new Synergies Plus panels, MicroScan enables laboratories to adapt to ever-changing demands; whether from the environment or from so-called superbugs, which are highly resistant to standard range antimicrobials. MicroScan was prominen

Dade Behring's new automated microbiology system, Microscan

t in detecting the first isolates of Vancomycin Resistant Staphylococcus aureus known as VRSA, as well as Vancomycin Intermediate Staphylococcus aureus (VISA) organisms.

At the heart of the MicroScan system are three major components which allow for total flexibility and configuration to meet the needs of different laboratories. Walkaway SI 40 and Walkaway SI 96 automated instruments can process, either 40 or 96 panel configurations respectively. With the larger unit, 96 identifications and 96 antimicrobial susceptibilities can be carried out at any one time. Engineered for optimal performance and flexibility, these systems accommodate multiple workflow options and can automate over 90% of the routine ID/AST workload. The autoSCAN 4 is a semi-automated system that allows small volume manual panel processing and automated reading and interpretation. This processes panels in seconds, simplifying ID/AST testing while standardising results, making it an ideal supplemental system for difficult organisms.

The biochemical and antibiotic susceptibility panels for all three instruments are supplied with 96 well plates of dried reagents. This means they can be stored at room temperature, removing the need for refrigerated storage and yet have a one-year shelf life. The Dried Conventional panels, either gram negative or gram positive, can be supplied as identification only, antimicrobial testing MIC or Breakpoint only, or as a combination panel, which allows both ID and AST to be performed concurrently.

Results are reported the next day, when resistance has developed and can be properly expressed. When needed, panels are automatically extended for 24 hours to allow for further resistance expression for Oxacillin and Vancomycin. These panels are the first ID/AST products with FDA clearance for testing VISA and VRSA. They also now include ESBL identification and confirmation on the same plate, removing the need for further costly confirmation work.
All panels conform to the Clinical Laboratory Standards Institute (CLSI) guidelines and in the future the LabPro software will be updated so the products have the ability to adapt to other regulations such as those imminent from the British Society for Antimicrobial Chemotherapy (BSAC).
Incubated for 16-20 hours, the Dried Conventional panels offer a broad menu of current antimicrobials, whilst the combo ID/AST formats provide creative workflow solutions. Use of these panels reduces the supplemental testing costs and reporting delays associated with rapid systems. All interpretations on the automated systems are controlled by the Lab Pro software, a configurable and customisable software suite coupled with a comprehensive Alert system. There is also an extensive identification database of gram-negative and gram-positive organisms.
As well as the conventional panels, the MicroScan Product Range includes other specialty panels including the newly available Synergies plus panels. These combine rapid identification with Read-When-Ready technology, overcoming the limitations inherent in fully rapid methods.

Direct MIC susceptibility in Read-When-Ready formats combined with a 2.5 hour identification, provides key antimicrobial results in as little as 4.5 hours yet will automatically extend susceptibility incubation to 16 hours when needed to express accurate resistance. The software will also enable Read-When-Ready antibiotics to be read and reported as they complete, enabling a quick check to be made on the first-choice antibiotic. As the LabPro Alert System is customisable for Critical Alerts, it can notify staff of results that should be addressed right away, improving productivity and facilitating the communication of critical patient results.
Other specialty panels in the portfolio include ESBL plus panels, which most closely align with the CLSI reference method for the confirmation and susceptibility testing of potential ESBL-producing strains of K. pneumoniae, K. oxytoca, E. coli, and other strains of Enterobacteriaceae, such as P. mirabilis.  There are also Rapid panels that offer a same-day turnaround alternative for common, high-volume gram-negative bacteria with identification available in 2.5 hours and AST in 3.5 – 7 hours. Chromogenic panels provide Yeast, Haemophilus/Neisseria and Anaerobe identifications in 4 hours while MICROSTREP plus panels offer identification to species level and a full range of antimicrobials for cost-effective and accurate streptococcal and Haemophilus* AST testing.
Dade Behring’s PROMPT inoculation method, reduces preparation time by over 40% when compared to turbidity methods. Three small colonies are all that are required in order to inoculate with the PROMPT method.

The LabPro software is the other key component as it enables multiple systems to be linked together and communicate with the laboratory information system. Its New Alert Resolution History feature keeps a record of actions taken by the laboratory to confirm and finalise atypical results. Together, the LabPro Information Manager and the LabPro Alert System software eliminate manual review for unusual conditions or results and integrate laboratory-specific resolution guidance into a laboratory’s workflow. Operation is easy to use and quick to learn, with minimal training.

With the launch of the MicroScan product range, the microbiology laboratory obtains a further choice in how to set up a truly flexible, cost effective solution to meet the challenge of super bugs, process automation and cost reduction in the hospital environment.

By Alan Freke, Marketing Director , Dade Behring Limited. Alan spent 17 years working for the Public Health Laboratory Service based at the South West Regional Laboratory in Bristol, eventually becoming head of the Virology Dept. He is a qualified Virologist  and External examiner for the Oral examination for Virology and lecturer for Microbiology on the HND and Special Courses in Microbiology and Virology and has previously lectured for WHO and UNIDOG on Chlamydia as part of the educational programs in STDs.  He has 19 years commercial experience with Diagnostic companies in all product and commercial areas and held various global and regional positions. Alan is the commercial Virology representative for BIVDA.