2024-07-18 03:06:27
The fungus named Rhodosporidiobolus fluvialis, was found in clinical samples from two unrelated hospital patients. During the experiments, the researchers found that the fungus was resistant to several first-line antifungal drugs at higher temperatures – about that found in the human body. Such temperatures also produced “hypervirulent mutants” capable of causing more severe disease in laboratory mice.
The results of the study “support the idea that global warming may promote the evolution of new fungal pathogens,” wrote the researchers, who published the finding June 19. žurnale „Nature Microbiology“.
The researchers made this discovery after examining fungi sampled from patients in 96 hospitals in China between 2009 and 2019. period. A total of 27,100 strains were collected and studied, of which only R. fluvialis has never been seen in humans before.
R. fluvialis was detected in the blood of two unrelated patients who were not only infected with this fungus but also had serious underlying medical conditions. One patient was a 61-year-old man who in 2013 died in an intensive care unit in Nanjing, and another was an 85-year-old man who died in 2016. after treatment in the intensive care unit of Tianjin. The report does not indicate whether the fungal infection directly caused the death of these patients or whether they were simply infected at the time.
Patients were treated with standard antifungal medications, including fluconazole and caspofungin. Later, after conducting laboratory tests, the researchers found that R. fluvialis is resistant to both of these drugs.
“This is a great and really unexpected finding that bodes badly for the future,” David Denning, a professor of infectious diseases at the University of Manchester in the UK who was not involved in the study, told Science.
Invasive fungal infections, which affect tissues deep in the body, are more common in people whose immune systems are weakened, such as by HIV infection or the use of immunosuppressants. It should be noted that a 61-year-old person infected R. fluvialiswas immunosuppressed, and the 85-year-old had diabetes, which can complicate the immune system.
However, rising global temperatures are causing the fungus to adapt and expand its geographic range, so some of them may encounter humans more often. This has led to the emergence of new pathogens, including drug-resistant ones Candida auris, which has been found in more than 40 countries since its discovery in 2009. Meanwhile, the development of new anti-fungal drugs has largely stalled, leaving few options to fight resistant infections.
In a new study, researchers R. fluvialis infected immunocompromised mice and found that some fungal cells rapidly evolved and began to grow more aggressively. The team then observed the fungus in laboratory containers kept at about human body temperature of 37 degrees Celsius. At this temperature, the fungus mutated 21 times faster than at room temperature, ie around 25 C°.
Because of the heat R. fluvialis was also more likely to become drug resistant. Under the action of the antifungal drug amphotericin B, the fungus acquired resistance at body temperature more quickly than at room temperature.
If such a fungus as R. fluvialis is more likely to become virulent and drug-resistant at high temperatures, global warming may encourage the evolution of new dangerous fungal pathogens, the team writes.
But speaking specifically about R. fluvialis, some scientists say that one should not jump to conclusions. Matthew Fisher, professor of epidemiology of fungal diseases at Imperial College London, who was not involved in the study, told Science that the fungus should not yet be considered a major emerging threat.
“My first hunch is that there is an unexplored environment in China where this fungus lives, and that these two patients were unlucky enough to be exposed to this fungus,” he said.
In short, there is no evidence that R. fluvialis would be widespread in the population, despite its alarming properties, according to Live Science.
2024-07-18 03:06:27