More study into impact on cell mitochondria (“powerhouses”) called for
LAUSANNE, SWITZERLAND – Researchers at Swiss and Dutch universities are calling on fellow scientists to look more deeply into the impact of a group of antibiotics on our cell mitochondria – cells’ “powerhouses”. Tetracyclines, widespread, should be used with greater caution, according to a report published by EPFL in the journal Cell Reports 13 March.
“Significant effects” in amounts found in food crop soils
EPFL in a statement, notes
“No one assumes that antibiotics are completely harmless. But a new study shows that some of them have unexpected consequences on the development of a wide variety of organisms. Scientists have observed significant effects in concentrations similar to those found in the soils in which our food crops are grown...
… Delayed development
The effects were huge. “After several days of treatment with high doses of doxycycline, mitochondrial respiration was visibly altered,” explains Moullan. More surprising still, the consequences were observed all the way down the food chain, from mammals to flies to nematode worms to plants. “The worms’ development was hindered. On the other hand, signs of aging appeared more slowly, something we had observed in earlier studies .”
The scientists also carried out growth tests on Arabidopsis thaliana, a common plant that’s frequently used in laboratory research. After growing for a week on a normal substrate, it was transplanted into soil with varying concentrations of doxycycline. “Delays in growth, some quite severe, were observed after a few days, even in soils in which the concentration of antibiotics was no stronger than is found in some agricultural soils today,” says Moullan.
From forage to field
This pollution whose consequences are just beginning to be appreciated is caused by the widespread administration of antibiotics to livestock. “Because they are give orally in feed, they are only partially digested and end up in manure, which is then spread on the fields,” explains Mouchiroud.
The quantities involved are huge, and the economic stakes equally sobering. In 2011, 5.6 million kg of tetracycline was administered to US livestock. A study showed that nearly half of the 210 kg of antibiotics produced in China in 2007 were tetracyclines for veterinary use. “The effects on growth of plants other than A. thaliana have not yet been studied, but our work indicates a need for caution,” says Moullan.”