By Renee Dilulio

 Sometimes, it’s the waiting that kills you — not usually literally, although the risk is there for a patient awaiting urgent test results. Bacterial identification and susceptibility testing has not traditionally been a fast test, requiring 24 hours to develop cultures. However, advances have allowed results to be obtained more rapidly than in the past, resulting in better patient care and improved lab economics.

 The newest product by bioMérieux Inc, VITEK® 2 Compact, is expected to bring these advantages to small and mid-size laboratories. Currently awaiting approval by the Food and Drug Administration (FDA), the VITEK 2 Compact uses the same technology as the VITEK 2 to deliver results the same day, but with a smaller footprint.

Product Development
The original VITEK was developed by the McDonnell Douglas Corp of St. Louis, Mo, for the aerospace program, but its clinical applications were realized and developed by what became the VITEK subsidiary of the company. The product was sold to bioMérieux, a French company, in 1992, before McDonnell Douglas’ merger with Boeing.

 bioMérieux immediately set out to bring the product to the next level and introduced the VITEK 2 in 1998. The system was designed to introduce workflow efficiencies and sophistication for larger laboratories. In 2001, the company began development of the VITEK 2 Compact to offer the technology within a smaller unit.

“It is always a challenge to transfer technology to a new, smaller platform while keeping the system affordable for customers,” says Beth Cosey, senior marketing manager, Microbiology, with bioMérieux. But the company achieved its goal, and the VITEK 2 Compact is expected to be on the market in the summer of 2005.

How It Works
The VITEK 2 and VITEK 2 Compact use a standard inoculum to prepare an organism suspension and sophisticated algorithms to analyze parameters and test conditions. A variety of susceptibility cards used in the instruments are available to allow an institution to match the susceptibility testing to its pharmacy antibiotic formulary.

Each susceptibility card contains 64 small-volume wells, with representative antibiotics in each well. The optical system reads the wells every 15 minutes. “The new photometric technology in the instrument takes advantage of advances in optics to detect changes in growth for each well. The system also can identify an organism’s phenotype based on the antibiotic susceptibility through pattern recognition using the Advanced Expert System (AES),” says Larry Donahoe, marketing manager, Microbiology, at bioMérieux.

According to Donahoe, portions of the setup and process can be completed by a low-level technologist or technician, but validation requires a laboratory technologist, though not necessarily one specializing in microbiology. The AES helps with verification. “This software package puts a PhD-level review in the hands of the small lab, which typically lacks the scientist traditionally needed to run this test,” Donahoe says.

The VITEK 2 Compact does not feature as much automation as the VITEK 2, but it does eliminate a number of manual steps, allowing consistent handling of the test process as well as time and cost savings. In addition, the expanded menu eliminates the need to run extra tests

Donahoe reports that the mean time for result delivery is 6–8 hours. “Roughly 80% of identification and susceptibility results are delivered in 6 hours, 90% within 8 hours,” he says. “This means that nine of ten patients could have their results in 8 hours or less.”

Quicker Results Lead to Better Treatment
Speed provides all types of benefits for the patient, the physician, the laboratory, and the facility. These include improved patient outcomes; early detection of nosocomial infections; detection of emerging resistances; MIC-based epidemiology; productivity, operating costs, and therapy adjustment savings; and a positive impact on therapeutic failure and microbial resistance costs.

A 1994 study published in the Journal of Clinical Microbiology reports that same-day reporting can have a clinical impact and is associated with significant cost savings.1 “Better clinical outcomes for patients mean they require fewer drugs and can leave the facility sooner,” says Donahoe.

The study researchers found a positive clinical impact as a result of rapid testing. They noted significantly fewer laboratory studies, imaging procedures, days of intubation, and days in ICU/intermediate care in the rapid test group; significantly shorter lengths of elapsed time prior to alternations in antimicrobial therapy; and significantly lower costs for hospitalization.1

Physicians are better able to make treatment decisions with faster knowledge, thus reducing the needless use of broad-spectrum antibiotics. A study led by Bergeron notes that in the past, patients suspected of suffering from severe or nocosomial infections have been treated empirically with broad-spectrum antibiotics.2 Physicians had a tendency to check the results of this test only if the patient did not respond to the treatment.2

With 80% of normally sterile specimens received in the microbiology laboratory not growing any microorganism, quite a few patients are therefore receiving antibiotics even if they do not have a bacterial infection.2 The researchers concluded that, “If physicians could have in hand the identity of the microorganism and its resistance profile from the microbiology laboratory at the same time that they have the biochemistry and hematology results, antibiotic prescription rates could go down dramatically, and when antibiotics are needed, more targeted and inexpensive antibiotics could be used.”2

Other Advantages for the Lab
While rapid result delivery brings benefits to the entire health care system, the laboratory sees many advantages firsthand. The automation available with the product enhances workflow, achieves full process control, and frees staff to perform other tasks, increasing efficiency.

The software is also user friendly. The simple point-and-click user interface is easy to master. An electronic information link provides “traceability.” The system’s data management program generates reports the laboratory must run, such as those for the hospital, for infection control and pharmacy, and for quality assurance. These include antibiogram or organism occurrence reports, says Cosey.

The unique test cards are designed to be light and compact, reducing the weight and volume of deliveries, storage, and waste disposal.

The system even provides health benefits for laboratory staff. An ergonomic study, commissioned by a VITEK client and performed by Worksite International Inc of Monterey, Calif, found that the VITEK 2 causes significantly less strain than another manufacturer’s automated ID/AST system. Using a Strain Index (SI) method to evaluate the level or risk for developing a disorder of the hand, wrist, forearm, or elbow from a certain job, the study found that the SI score for bioMérieux’s VITEK 2 Clinical Laboratory Scientist (CLS) work cycle over 2–4 hours was 6.75. Lower numbers are more ideal. The closest competitor on an identical CLS work cycle over 2–4 hours had a strain index of 60.75.

The information measures the likelihood of developing a musculoskeletal disorder (MSD) to the upper extremities. Reducing this risk means reducing injuries and the time and productivity lost as a result. VITEK representatives cite the Bureau of Labor Statistics’ 2002 report, the most recent to date, which states that MSDs accounted for 34%, or almost 500,000, of the injuries and illnesses that required days away from work.

In addition, the laboratory benefits from increased recognition. “Labs gain recognition by becoming more important as a clinical team player in the care of the patient. This gets microbiology out of the microbiology lab,” says Cosey.

Renee DiIulio is a contributing writer for Clinical Lab Products.

1. Doern GV, Vautour R, Gaudet M, and Levy B. Clinical impact of rapid in vitro susceptibility testing and bacterial identification. Journal of Clinical Microbiology. 1994; 32(7):1757-1762.
2. Bergeron MG, and Ouellette, M. Preventing antibiotic resistance through rapid genotypic identification of bacteria and of their antibiotic resistance genes in the clinical microbiology laboratory. Journal of Clinical Microbiology. 1998; 36(8):2169-2172.