Toxicity of the different vegetative stages of Amorimia pubiflora to sheep

Lima, Stephanie C.; Godoy, Kelly C.S.; Leal, Paula V.; Lee, Stephen T.; Pfister, James A.; Leal, Juliano de Souza; Barros, Cláudio S.L.; Lemos, Ricardo A.A.

doi:10.1016/j.toxicon.2018.11.306

Cited by 3 publications

(1 citation statement)

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“…MFA leaf contents in A. amazonica, A. exotropica, A. rigida and A. pubiflora were 0.0007, 0.02, 0.002 (Lee et al 2012) and 0.22% (Lima et al 2019), respectively. In A. septentrionalis, collected in Paraíba state, the concentrations found varied according to plant part: 0.002% in mature leaves, 0.001% in stems, 0.008% in flowers, and 0.006% in seeds (Lee et al 2012).…”

Section: Introductionmentioning

confidence: 93%

Techniques for prevention and control of poisoning by sodium monofluoroacetate (MFA)-containing plants in ruminants

2019

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Monofluoroacetate (MFA)-containing plants cause sudden death associated with exercise in ruminants, and are responsible for significant losses in Brazilian livestock, estimated at 500,000 bovine deaths annually. Most of the times, the control and treatment of this type of poisoning are not efficient, because disease evolution is superacute, usually causing the death of the animal. Due to the difficulty in controlling this intoxication, several studies have suggested alternatives to prevent it, mainly by making animals resistant to the MFA present in these plants or by avoiding their consumption. This literature review addresses the techniques used experimentally to control the poisoning of ruminants by plants containing MFA. The first studies carried out in Brazil demonstrated that goats and sheep that continuously receive non-toxic doses of plant containing MFA show greater resistance to poisoning than untreated animals, and that this resistance can be transmitted by ruminal fluid transfaunation, suggesting that poisoning occurs due to the presence of bacteria that hydrolyze MFA in the rumen. Based on this hypothesis, several MFA-hydrolyzing bacteria were isolated (Enterococcus faecalis, Bacillus sp., Paenibacillus sp., Burkholderia sp., Cupriavidus sp., Staphylococcus sp., Ancylobacter sp., Ralstonia sp., Stenotrophomonas sp., Pigmentiphaga kullae, and Ancylobacter dichloromethanicus). When some of these bacteria were administered intraruminally, they provided the animal with a different level of protection against poisoning. However, it was observed that protection is gradually lost when the bacterium administration is interrupted. Consequently, to obtain more efficient protection, these bacteria should be administered continuously, probably in the form of probiotics. In another assay, MFA was administered to sheep at non-toxic doses to test the hypothesis that this substance could induce the multiplication of bacteria that hydrolyze it in the rumen. There was no increase in resistance to poisoning after administration of MFA; however, no signs of poisoning were observed when animals received trifluoroacetate and no clinical signs were verified when they were challenged with toxic doses of MFA; in contrast, all control animals presented clinical signs. These results suggest that trifluoroacetate induces the proliferation of MFA-degrading bacteria, and can be used in intoxication prophylaxis. The conditioned food aversion technique, using lithium chloride, has been successfully used experimentally to prevent ruminants from ingesting plants that contain MFA. Another alternative tested was the spraying of Amorimia septentrionalis with the endophytic bacterium Herbaspirillum seropedicae, which degrades MFA, resulting in decreased concentration of this compound in the plants. In conclusion, several experimental techniques have been proved efficient in the control and prophylaxis of MFA-containing plant poisoning; however, none of these techniques are available commercially. Further experiments, mainly in the field, should be carried out to adapt some of these techniques to the conditions of extensive breeding in the numerous areas where MFA-containing plants occur.

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Section: Introductionmentioning

confidence: 93%

Techniques for prevention and control of poisoning by sodium monofluoroacetate (MFA)-containing plants in ruminants

2019

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Isobiology: A Variational Principle for Exploring Synthetic Life

Danchin

2020

ChemBioChem

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Most developments in synthetic biology try to depart from life as we know it, attempting to create orthogonal constructions. Here, following a variational principle, I try to explore how slight changes in the buildup of cells reveal critical features of life's physics. In a first section, I suggest that we use stable isotopes of the atoms of life to see how living cells fare, beginning with life in heavy water. Subsequently, isotopes of the other main biogenic atoms are suggested as an extension of the variational principle, despite their likely very small influence on the course of biological activity. Finally, two atoms of the second row of Mendeleev's table, boron and fluorine are explored as a further extension of the principle. The use of the former is still in its infancy, whereas the latter, based on existing fluorinases, could open the door to a more general use of halogens in synthetic biology.

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