At Lutheran Hospital, lab supervisor Mary Shoaff holds a clear plastic disk filled with reddish gel up to the light. Little pinpoints streak across its surface, meaning something bacterial is growing.
That’s not good news, because the gel was inoculated with a sample of a patient’s blood.
In the old days, she says, a lab worker would have eyeballed the sample, prescreened and allowed it to incubate for hours or days, and decided, based on experience, that it looked like certain nasty bacteria – say, Staphylococus aureus, which causes serious, even potentially fatal, infections.
Then, further tests would have to be run, and doctors would have to decide which antibiotic drug to give – even though they wouldn’t know whether the drug would work.
But lately at Lutheran’s lab, human eyes have been augmented with a new instrument with high-tech “eyes.” The technology can take a blood sample that has tested positive for bacteria and pinpoint in hours not only the kind of bacteria that’s growing but also which drugs are likely to be effective.
“I think this is the way things will be done in the future,” Shoaff says.
The instrument is known as the Verigene System, and Lutheran was the first hospital in Indiana to use it, says Steve Smith, sales representative for the instrument’s maker, Nanosphere of Northbrook, Ill. The hospital now is the only one in northern Indiana to have the technology, he says.
Parkview Hospital is looking into using a similar system, with or without the Verigene instrumentation, but no timetable exists for acquisition, spokesman Eric Clabaugh says.
Dr. April Morrison, Lutheran’s interim medical director for infection control, says the instrument combats a serious problem – the rise of bacteria that have mutated so that typical drugs don’t eradicate them.
Dubbed “superbugs” by some, the bacteria include MRSA – methicillin-resistant Staphylococus aureas, also known as the “flesh-eating bacteria” that attacks the skin – and VRE – vancomycin-resistant Enterococcus, which can live harmlessly in the body but also cause infections in the urinary tract, the bloodstream, or wounds associated with catheters or surgery.
“The problem is (that) we’re starting to get infections that are difficult to treat, and there are fewer and fewer (effective) antibiotics,” she says, adding that doctors are particularly concerned when resistant organisms get into the bloodstream.
“Bloodstream infections, when they’re not adequately controlled, can lead to multi-system organ failure and, in the most serious cases, death,” she says.
Dr. Chris Dempsher, Lutheran’s laboratory medical director and chief pathologist, says that when they can, doctors want to reserve broad-spectrum antibiotics – ones effective at killing a wide swath of bacteria – for the most serious cases. One such drug is vancomycin, he says.
“It’s still a very important antibiotic, but there are some times we can’t use it because there’s resistance to it,” Dempsher adds, citing VRE infections. Most occur in hospitals, and they often occur in people with a weakened ability to fight off germs, according to the federal Centers for Disease Control and Prevention.
The agency says resistant bacteria pose a major public health concern, and it recommends that hospitals implement “antibiotic stewardship” programs to help patients get antibiotics only when necessary and to ensure they get the right drug for the right amount of time. That’s what Lutheran is doing with the aid of the Verigene, Dempsher says.
How it works
The instrument uses nanotechnology, which can “see” down to the genetic level of bacteria. It essentially cuts up a bug’s DNA and isolates mutations that cause resistance and exposes them to a molecular tag that “lights up.” Results can be displayed on a screen, stored and printed out in easy-to-read English.
The process happens on a cartridge about the size of one used to hold printer ink in an instrument about the size of a suitcase. And, says Dempsher, it shaves a process that could take one to five days down to as little as two to three hours, crucial because of the urgency of disease progression.
Shoaff says the Verigene is used two or three times a day, only when a prescreening reveals the presence of bacteria in a patient’s blood. The instrument, she says, already has proved its worth.
Sarah Jones, a pharmacy resident at Lutheran, recalls one patient who had been diagnosed with endocarditis, an inflammation of the lining or valves of the heart and a blood infection. The patient was being treated with vancomycin, but the bacteria, when tested with the Verigene, turned out to be a resistant strain.
“We were able to switch to linezolid,” she says, referring to an antibiotic which is typically reserved for the most serious infections. It is used short-term because of concern about side effects, the CDC says.
Jones is now working on studies that will further document the results of the Verigene System on patient outcomes, length of stay and cost of treatment.
A limitation of the Lutheran’s Verigene is that it works only with gram-positive bacteria, Shoaff says. But a gram-negative test covering the other of the two bacterial classes was approved by the FDA in January, Smith says. Lutheran should be getting gram-negative capability in a month or two, Shoaff says.
Traditional identification methods are still used to confirm infections, she says, but treatment can be started before those tests are finished, based on the Verigene results.
“They’re what I call an early adopter (of the technology),” Smith says of Lutheran’s professionals, noting that about 200 hospitals nationwide are using the system. “For Lutheran to bring this on as a community-based hospital is showing they’re progressive as an institution.”
Dempsher says the Verigene system is a great tool, especially when combined with teamwork among doctors, lab workers and pharmacists.
“It’s important to stay vigilant,” he says. “Every hospital is going to have superbugs. We’re just happy we have technology that will allow us to treat them appropriately and faster.”