Recognize Pathogenic Bacteria Early
The human biologist Dr. Mareike Müller is studying the communication of bacteria at the University of Siegen, especially in biofilms. On the basis of this biomedical research, she wants to develop methods to detect pathogenic bacteria early on and locally.
Whether in kitchens, pipes or breathing tubes - wherever it is moist and warm, biofilms can form, i.e. mucus layers of bacteria and fungi. Sometimes they can affect entire hospitals because they become resistant to disinfectants and antibiotics. Bacteria are extremely adaptable, you could also say "smart", and communicate with each other to be more successful. The human biologist Dr. Mareike Müller from the Department of Chemistry - Biology of the University of Siegen is researching this communication and the behavior of the bacteria. The goal: to develop an early warning system to prevent the development of pathogenic biofilms.
"Many bacteria are harmless as individual cells," explains Dr. Mareike Müller, who works in the research group "Physical Chemistry" of Prof. Dr. Holger Schönherr, "if they organize themselves in biofilms, it becomes more difficult. 80 percent of the pathogenic bacteria develop in biofilms. "Müller and her international team work with genetically modified bacteria, developed by the cooperation partner NUS Singapore. These "reporter" bacteria respond to the communication of other disease-causing bacteria by lighting up. "Bacteria release signal molecules, which is like speaking," explains group leader Prof. Schönherr, "and they receive these molecules with receptors, which is analogous to hearing." The reporter bacteria used by the Siegen scientists produce these special molecules without the ability to "speak in that language", but only "listen" to the communication of the other disease-causing bacteria. "At the moment, we can only see the glow of the reporter bacteria under a special fluorescence microscope," says Müller, "but we are well on the way to developing test strips that detect pathogenic bacteria, before the bacteria form a biofilm. These will then be visible to the naked eye."
The research requires interdisciplinary collaboration between biology, chemistry and materials science. So have, for example, the researchers Ping Li and Dr. Xiaoqiu Dou together with Dr. Mareike Müller developed a hydrogel matrix as part of a ZIM cooperation project with the Siegen company Quh-Lab Lebensmittelsicherheit, which reliably encapsulates the reporter bacteria and protects them against external influences. At the moment they are still dealing with pure cultures, i.e. with bacteria of a kind. But since such pure cultures in everyday life almost never exist, mixed cultures are to be observed in the future.
Currently, Dr. Mareike Müller and her junior research group investigate the “effect of estradiol on the formation and dynamics of bacterial biofilms” as part of the medical research project, focusing on the relationship between bacteria and a female hormone. This project is funded by the Equal Opportunity Office of the University of Siegen. "It is noticeable that with some infections women show a less favorable course of disease, which seems to be associated with the development of particularly robust bacterial biofilms that make it difficult to cure certain infections," explains Müller. "That could be related to the concentration of the hormone estradiol." How high the estradiol level is depends, among other things, on the female cycle. With the research results, physicians would be able to tailor the treatment of certain infections and tailor it to the individual patient. It is well known that bacteria react to human hormones: "Salmonella, for example, recognize stress hormones," explains Müller, "so they know exactly when humans are particularly vulnerable."
Dr. Mareike Müller has been studying bacterial communication since 2012. In 2014, she came to the University of Siegen as part of a research project and since then has worked in the group of Prof. Dr. Holger Schönherr. Since the beginning of the year she has been heading the junior research group "Biofunctional Materials for Cellular and Applied Microbiology". For her interdisciplinary life science research work, which includes biology, chemistry and materials science, she received the Future Prize of the Research College "Shaping the Future of Human Development" at the University of Siegen.
Dr. Mareike Müller
Junior Research Group: Biofunctional Materials for Cellular and Applied Microbiology
Prof. Dr. Holger Schönherr
Research Group Physical Chemistry I