Microbiology

Without cleanability, there is greater bacteria growth, and when it comes to emerging foodborne pathogens, Kornacki says it is still unclear what, in fact, causes illness and more methods are needed to detect those sources.

“There is no effective tissue method to identify and recover these organisms,” he says. “We need to get to a point with actionable results without a culture, and there’s a lot of pressure to do that. There are people who say they have those types of assays, but I’ve been burned before. It’s got to be culturally confirmed. Some of these PCR-based tests are great. The rate of false-positives is minimal, but the government wants to see a culture, and that has tremendous consequences. The last thing you want to be is wrong. You have to make absolutely sure that it’s a positive.”

There also needs to be unity in the field of applied microbiology, and he says that means establishing a lab quality system accredited by ISO 17025, a standard that outlines general requirements for the “competence of testing and calibration laboratories.”

According to ISO, about half of the 50,000 laboratories worldwide are accredited under the standard, which is a must for labs in the European Union. The standard was updated from the 1999 version to make it compatible with ISO 9001:2000, which sets requirements for management systems in businesses and other organizations. The changes were a must because more businesses are opting for ISO 9001:2000 accreditation, including those that testing and calibration laboratories serve.

The modifications place more requirements on top management in their oversight of such laboratories. The new ISO standard also requires accredited laboratories to demonstrate a commitment to continually improve the effectiveness of management systems. A laboratory must also demonstrate they have a program to continually improve customer satisfaction and communications.

“You gain confidence in testing by having a comprehensive lab quality system that allows you to stand behind your results,” Kornacki says.

Key elements to having a solid lab quality system are knowledge of the method and having it written out when a positive result is reported. “Labs are very unique,” he says, adding that it isn’t enough to just say that a method or lab practice is FDA or BAM approved.

Training is also a key element. Technicians must be competent, and that proficiency hangs on clearly-written testing requirements, Kornacki says. “The technicians must read (testing requirements), observe it and then perform it under supervision to prove they can do it well,” he adds.

While equipment calibration and maintenance schedules are givens, and include everything from thermometers to large pieces of equipment, contamination control must also be a priority.

A lot can go wrong quickly if contamination control protocols are not in place. Kornacki recalls one particular lab study for a company that believed it had created Salmonella-resistant eggs, and it involved inoculating yokes with a particular strain.

During that experiment, the tray of plates was tipped over. The technician quickly picked the plates up, sanitized her hands and then set up a separate set of plates, contaminating that experiment with her hands.

The arrangement of test tubes can also usher in cross-contamination. “There needs to be a separation between critical areas to avoid cross-contamination,” he adds.

Proper sampling and comprehensive tracking of samples is also important, for data from botched sample is of no value.

“ABC Company samples may be in the same rack as samples for XYZ Company, and you test both and both tests come back positive,” Kornacki says. “Then you have to ask yourself, which one was positive first. You have to document what you’re doing so you can save yourself the embarrassment and your client the frustration.”