gulp! is it bad to drink old water?
we have all taken a swig of water that has been sitting in a glass or bottle for a couple of days, but we could be swallowing more than just h₂o.
the team found drug-resistant strains of candida auris— a fungus that can cause persistent and severe infections and widespread outbreaks—on the surfaces of two common varieties of stored apples which had been treated with fungicides to extend shelf life.
for the study, recently published in the journal mbio , the team analyzed samples from nine different tropical and temperate fruits, both fresh and stored, which were collected from new delhi and other regions of india in 2020 and 2021.
researchers swabbed more than 60 apples for c. auris and other yeasts, eight of which were positive, including samples from two common species of apples: royal gala and red delicious.
the results suggest the apples could be a pathway for the yeast, helping it to spread more widely, says jianping xu, a professor in mcmaster’s department of biology and researcher with canada’s global nexus for pandemics and biological threats , who collaborated with lead author anuradha chowdhary, a professor of medical mycology at the university of delhi.
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c. auris was first discovered in japan in 2009 and has since spread all over the world. it often infects immunocompromised hospital patients.
with a study published last year, also in mbio , xu and chowdhary became the first team to isolate c.auris in a natural environment, on the sandy beaches and tidal swamps of the tropical andaman islands in india’s bay of bengal. before then, the yeast had only been found in human environments such as hospitals.
in 2019, the u.s. centers for disease control and prevention classified c. auris as one of five pathogens posing the most urgent threats to public health. antifungal medications often do not work on c. auris , and more than one in three patients with serious and invasive infections will die.
the discovery of multi-drug resistant c. auris on the surface of stored apples provided the first evidence that an anthropogenic environment have likely contributed to the development and spread of antifungal resistance in c. auris. additional environments facilitating drug-resistance development will likely be found in the future, says xu, who is studying how the fungus reproduces in nature.
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“we need to expand the ecological niches that we are investigating for at least the fungal pathogens that are capable of growing and reproducing in multiple types of environments. by no means is the stored apple surface the only ecological niche where candida auris can exist and select for drug resistance.”