Differentiate between a virus and a bacterium

Researchers have discovered how to distinguish between viral and bacterial infections in patients using the level of light emitted from their blood sample

A multidisciplinary research group from Ben-Gurion University of the Negev, led by Prof. Robert Marks, in collaboration with doctors from the Soroka Medical Center led by Dr. Boris Rogchiov, discovered a way to distinguish between viral and bacterial infections in patients, with the help of learning the level of light emitted from a sample their blood. The light is a unique measure of the ability of the phagocytic cells (Polymorphonuclear leukocytes) to fight infections in the human body and indicates the ability of the cells to produce oxygen radicals (Reactive oxygen species).

This breakthrough grabbed the headline in the scientific journal Analytical Chemistry, where the research was published these days. The discovery is the result of the work of the PhD student within the Foundation for Integrated Technologies, Daria Prilotsky.

Prof. Marks: "The discovery by our research team will allow for a better diagnosis, as well as preventing inappropriate use of antibiotic prescriptions."

Diagnosing infections of bacterial origin versus infections of viral origin is not a simple task for doctors and medical staff. The tests that are in use today are an effective and necessary tool in selecting and adjusting the appropriate treatment for the patient, but they take up valuable time. The symptoms for both types of infections are very similar, but the way they are treated is completely different. In the case of a bacterial infection, the treatment is based on the use of antibiotics, while in the case of a viral infection, the use of antibiotics is ineffective and even harmful and causes the development of drug resistance, which increases the chance of causing complications in antibiotic treatment in the future. The researchers propose an innovative method based on the activity of the patient's innate immune system, considering that its reactions vary from disease to disease. It turns out that engulfing cells ("phagocytes") are capable of being used by researchers as a tiny laboratory, through which diagnostic information can be produced.

Prilotsky: "Swallowing cells (or "phagocytes") are the main defense cells that are mobilized during the outbreak of infection. The phagocytes produce large amounts of active oxygen products, a process responsible for killing the foreign organisms that enter our bodies. When the phagocytes are 'stimulated' by the presence of luminol molecules, the cells respond with a light-generating reaction (chemiluminescence). The phagocytes move through the body in a stimulated state, which is 'oriented' to future tasks. This arousal state reflects the organism's readiness to defend itself and has a predictive value that can be used as a sensitive marker for a specific infection, that is, to differentiate between different types of infections and therefore can be used as a diagnostic tool." The researchers' findings indicate that there is great potential in using this system to determine phagocyte activity in various pathological processes and hope that this tool can be used for the purposes of assessing the state of the immune system, predicting the outcome of various diseases and predicting the factor involved in the functional change of the immune system.

In order to differentiate between viral and bacterial infections, the researchers recruited patients who attended the emergency department at the Soroka Medical Center and were found to have a high fever index. The experiment measured the ability of the phagocytic cells to produce oxygen products and the amount of light emitted from the patients' blood samples. After that, the researchers were assisted by the extensive knowledge of Prof. Mark Last from the Department of Information Systems Engineering at Ben-Gurion University and used various algorithms for data mining, in order to extract important information and try to find patterns in the behaviors of the cells in question in different infection situations. The study highlights the differences in the production of light by phagocytes in cases of different infections and amounts to an accuracy of almost 90% in the classification of cases of double blindness (Blind cases).