A group of scientists from CONICET This is what they found out Acinetobacter baumanniia bacterium that is resistant to many Antibiotics and often in Hospitalshas one biological clock that fits with it Light. The research, led by experts from the Center for Photosynthetic and Biochemical Studies (CEFOBI, CONICET-UNR), helps to better understand how the microbes that cause diseases.
This way we can know how this works Superbug Organize your activities during the day and the Eveningwhich may influence how it is caused Infections And responds to treatments. The study was published in the scientific journal Communication biology and researchers from various national and international institutions took part, including the National University of RosarioThe National University of Quilmes and the Washington University School of Medicine.
This is what the investigation revealed Acinetobacter baumannii has endogenous circadian rhythms. That is, the bacterium follows internal cycles of almost 24 hours even when it remains under constant conditions, such as: darkness. To find out, the team used a technique that allows measurement activity of the gene blsAthe main thing Light sensorthrough a reaction from Luminescence. So they could observe how their Behave in various light and dark situations 23°C.
Maria Alejandra MussiLeader of the study and CONICET researcher at the Center for Photosynthetic and Biochemical Studies (CEFOBI, CONICET-UNR), explained in an official statement: “For many years we have been working on mechanisms of resistance to antibiotics. At some point this was a bit disappointing for us because bacteria always win the battle in the end and develop resistance, which means that there are no real solutions to combat them. At some point we discovered that these bacteria (Acinetobacter baumannii) sense light. And that was “a discovery.”
The results showed that the activity of the blsA gene adapts to cycles of blue light and darkness and that these rhythms are maintained even if the bacteria are left continuously in the dark, with a cycle close to that 24 hours. According to the scientific article, “blsA promoter activity can be synchronized with 24-hour cycles blue-dark light that is reset immediately after a phase change.”
Furthermore, the study showed that Acinetobacter baumannii It doesn’t just have one internal clockbut can also react actively to it Light the environment. The bacteria detect the presence or absence of blue light and adjusts his behavior accordingly. This means that the flash acts as an external signal that helps organize your biological activities and synchronize your internal rhythm with the Environmental changes.
The existence of these circadian rhythms in a bacterium normally causes infections that are difficult to treat in hospitals raises new questions about how these cycles may affect their ability to cause disease, survive in different environments, etc resist treatments. The scientific paper suggests that this mechanism “could modulate the persistence of bacteria in the environment, susceptibility to antibiotics and pathogenicity, influence virulence and open new avenues for the treatment of infections caused by these pathogens.”
Valentin PermineatCONICET PhD student at CEFOBI and first author of the paper, explained: “The interesting thing about our work is that it is the first time that these pathogens have been proven to exist.” They have a circadian rhythm and this somehow changes our understanding of an infection process because it was a variable that no one had ever considered. In fact, there is very little or almost no literature and studies on these circadian rhythms.”
The team designed an experiment in which they incorporated a special “sensor.” bacteriumwhich produces a small amount Light if the gene blsA is active. This allowed them to detect when the gene was activated or deactivated over time. The microorganisms were grown on plates at 23 °C, alternating 12 hours of blue light and 12 hours of darkness, and then kept there for several days complete darkness.
The scientists measured the amount every half hour Light produced by this system in bacteria. They observed that the activity of the gene blsA walked up and down and followed a constant rhythmboth when there were differences in light and darkness and when the bacteria remained in the dark.
To confirm that this rhythm corresponds to real changes within the bacterium And not just for measuring light, the team also analyzed that genetic material. They extracted RNA at different points in the cycle and checked the amount of genetic messages blsA It varied throughout the day.
In addition, the researchers worked with modified bacteria that did not have this ability blsA. They discovered that without this sensor the bacterium he could no longer adapt his rhythm to the changes in light, although his internal clock it still worked. The article states: “The overall results suggest that blsA is involved in synchronization with the zeitgeber (the temporal signal) but does not affect the endogenous component of the rhythm.”
“It’s like a human being, they have a cycle throughout the day that also depends on time. It’s well known that human immune system It is regulated by a circadian clock, which is why we get a fever in the afternoon or wake up during the day. So one of the hypotheses that we propose in the paper is that this is actually the case pathogens Synchronize your circadian rhythm with daylight to optimize it infection. Or at a time when they are better prepared. It could be that the pathogens Synchronize your daily rhythm with the rhythm of the People. And well, this is a new perspective that we would bring, because it is a new look at the infection process, but now from the perspective of the pathogen,” Permingeat summarized.
The discovery of circadian rhythms Acinetobacter baumannii introduces a temporal dimension into the study Bacterial physiology. The research highlights the possibility that these rhythms make this possible bacterium anticipate and modulate environmental fluctuations that could give it advantages in colonization and infection Antibiotic tolerance. According to the authors, “the existence of endogenous rhythms suggests that this pathogen has evolved mechanisms to anticipate periodic fluctuations in environmental conditions.”
The work suggests that the synchronization between the circadian rhythm The differences between the pathogen and the host could influence the effectiveness of treatments and the dynamics of the infection. The document notes that “changes in bacterial susceptibility to antibiotics, course of infection, or persistence in the environment, which may be influenced by the time of day.” Implement changes to treatment programs to optimize medical interventions and infection prevention crucial and offers new opportunities for the development of specific therapeutic strategies to combat infectious diseases.”
Research suggests investigating whether adjusting antibiotic treatments leads to this bacterial circadian rhythm can improve its effectiveness and analyze the interaction between Rhythms of pathogens and human immune system. This approach could open avenues for the development of targeted therapy strategies that they take that into account biological temporalitya variable that has been little researched in the field Clinical microbiology.
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