New technologies help combat infectious diseases

June 1, 2011

Physicians are faced with the daily challenge of obtaining reliable, actionable information as quickly as possible, then determining the best possible therapy for their patients to ensure swift and full recoveries. In the absence of rapid, detailed diagnostic information, doctors typically administer empirical therapy based on historical experience. Emerging technologies and applications of existing technologies combined with current tools will contribute exciting options to boost future diagnostic capabilities.

The microbiology laboratory, tasked with quickly furnishing critical test results requested by physicians, becomes the focal point in producing an array of information in the management of infectious diseases. With our mobile society — global travel and migrating populations — even the most experienced microbiologists may be faced with strains of bacteria never before seen in their laboratories.

Growth-based antibiotic-susceptibility testing is an essential tool; it determines drug resistance as it is actually seen in the pathogen. It is not simply a prediction of the expected organism resistance. In the past, if a patient had an unusual bug, he was treated empirically with a broad-spectrum antibiotic, without a true indication of the actual effectiveness of that antibiotic. History tells us that this approach is not optimum in preserving the effectiveness of our antibiotic arsenal.

Microbial organisms will continue to evolve, so knowing how the in vitro drug resistance expresses itself is essential to therapeutic efficacy. This is the best tool we have today to identify and monitor mechanisms of resistance expressed by microbial organisms. It could be a big step in preserving the antibiotic pipeline and ensuring the therapeutic value of those drugs.

With a more definite comprehension of the expression of in vitro drug resistance, a physician could target patient treatment more appropriately with better effects. Imagine his ability to better manage a patient’s clinical response while, in turn, minimizing the risk of the infection’s spread and better containing emerging resistance. Decreasing the propagation of antibiotic resistance and minimizing possible toxicity risk to patients would be a huge win globally.

New applications like mass spectrometry and new technologies for strain typing and gene sequencing proffer new options to give clinicians better diagnostic insight due to greater microbial organism discrimination and, perhaps, even some evolutionary information about the pathogen. This new clarity is like changing the lens or the resolution on a camera. As an example, mass spectrometry analyzes proteins by measuring the size of the protein’s particles after being hit by a laser. Mass spectrometry can be used to identify bacteria by analyzing an isolate’s protein pattern and comparing it to a library of patterns produced by various species of bacteria. Mass spectrometry can also look at patterns with more detail and give additional information about a bacterial cell, such as the strain’s pathogenicity.

These technologies can give us information about the transmission and the “risk map” for a specific organism. We can start examining the migration of strains and begin to better understand the migration of infectious diseases — critical for global epidemiology. In many cases, members of the same family or genus behave therapeutically in the same manner, while other strains may behave differently. Improving the discrimination at the early stages of a diagnosis, from family to genus to species — and even to strain level — holds the promise of significantly advanced treatment selection.

Marrying new technologies with existing test systems enhances our ability to learn about evolutionary organism patterns and response characteristics, so we may present information that allows more appropriate and effective patient therapy. By separating routine organisms from unusual ones, we can focus our diagnostic energies and concerns in areas that can best refine patient results and help manage infectious diseases on a global level.

Innovative technologies give us a different set of tools so that we may learn about organisms in a new light. These new tools, when combined in novel ways with the existing array of testing capabilities, may give laboratorians and physicians new ways of combating infectious diseases that should lead to better patient outcomes.

Doug Flammang is vice president of Microbiology Core Business Programs at bioM’erieux in St. Louis, MO.