Cycle 4 (2015 Deadline)
Monitoring the disturbance of the microbiota in Amazonian soils during conversion of forest to pasture and its consequences on cattle health
PI: Ederson Jesus (email@example.com), Embrapa (Brazilian Corporation of Agricultural Research)
U.S. Partner: James Cole, Michigan State University
Project Dates: October 2015 - September 2020
Pandemics of “swollen face,” a bacterial-origin periodontitis disease afflicting ruminant livestock, have been correlated with deforested areas in Brazil (Döbereiner et al., 2000). This disease, which is also known as "lumpy face," was commonly reported in Brazil during the 1960s and 1980s. New cases have recently been observed in sheep and goat flocks in the Amazon, under the same epidemiological conditions and with the same characteristics observed in bovines. In such circumstances, the disease has destroyed herds of livestock, often up to 90% of the animals. Dr. Jesus and his project collaborators hypothesize a link between the “swollen face” disease and shifts in the soil microbial communities as a consequence of deforestation and pasture introduction. This belief is based on previous evidence showing that this disease is triggered by deforestation, which in turn leads to significant changes in the soil communities, favoring specific populations such as actinomycetes. The team’s objective is to characterize correlations between the soil environment, changes in the microbial community due to deforestation, and the occurrence of this disease. Once more specific correlations are identified, they will experimentally test hypotheses (e.g., causation) generated through isolating key microbes and using culture-dependent and independent techniques. Answering these questions is important to advance towards a cure for the disease and design monitoring methods and alternative management to reduce its incidence. Additionally, confirming the link between the occurrence of diseases, deforestation, and changes in biodiversity will contribute to the delineation of policies to hinder deforestation and to promote biodiversity conservation. As part of the effort, the U.S. Government-supported partner, Dr. James Cole, will provide training and support with bioinformatic analysis of the datasets, sharing analytical tools he uses in his own research.
|Dr. Jesus (left) with U.S. partner Dr. James Cole of Michigan State University and Dr. Kostas Konstantinidis from Georgia Tech, along with a third U.S. partner, Dr. Adina Howe of Iowa State University at the MiGA workshop (photo courtesy of Dr. Jesus).|
The world’s growing population and their increasing demand for animal protein raises concerns over the pressure for the creation of new pastures to meet this demand, especially in countries like Brazil, which is the world’s leading beef exporter. New pastures are created at the expense of native lands, including the Brazilian Amazon. In fact, pasture introduction is the major driver of deforestation in the region, and alternatives to reduce this pressure are needed. Within this context, this project can contribute with information to support policymakers in their decisions, as well as to create alternatives to the sustainable management of pre-existing pasture lands. The results of this project may also contribute to designing sustainable, innovative management systems, such as the integrated crop-livestock-forest system, which has been recognized by FAO, the Ministry of Agriculture of Brazil, and Embrapa as an alternative to stimulate the use of pre-existing pasture lands, guarantee food and agricultural security, and discourage the deforestation of new areas for agriculture and livestock production.
Summary of Recent Activities
Dr. Jesus and his team continued working on sequence data analysis during the second and third quarters of 2019, including diversity and multivariate statistical analyses. In addition, field work continued on the second phase of the project, carried out in Araçatuba, SP, to evaluate the effect of pasture management on the appearance of periodontitis in cattle. Team members sowed a site with Panicum maximum (Guinea grass) after preparing the soil using conventional management practices such as liming and fertilization. The pasture reformation effort began in December 2018 and finished in March 2019. The area was subdivided into 20 plots in which the animals are rotated. Eight Girolando cattle, ages 8-10 months, were selected and introduced in these plots in May 2019. Since then, soil samples have been taken monthly. The oral cavities of the animals have been examined weekly and a detailed periodontal examination has been carried out every 15 days. Samples of biofilm have been collected and stored for future sequencing analysis.
On the outreach side, two students working on the project presented their work on conferences recently. Master’s student João Gabriel Barbosa Braga gave a presentation on Arbuscular mycorrhizal fungi associated with a mycoheterotrophic plant from the eastern Amazon at the International Symposium on Agricultural Microbiology, which was held at the Federal University of Lavras in August 2019. In September, PhD student Fernando Igne Rocha took part in the ISME Latin America Congress in Valparaiso, Chile, where he delivered a poster presentation entitled Understanding the effects of land use and soil type on the structure of soil bacterial communities in the Brazilian Western Amazonia.
During the final quarter of 2019 and into 2020, the PI and his fellow researchers will finish the statistical analysis of the first stage of the project and work on manuscripts for publication. PhD student Fernando Igne Rocha is finishing his analyses of soil communities, after which he will write a paper on the topic. This will likely take place in early 2020, as he will be leaving for Iowa State University in November to spend a year working on a fellowship from the Brazilian science agency CAPES. Fernando will work on the analysis of antibiotic resistance data during his stay with Dr. Adina Chuang, and a second paper is expected from that work. In addition, stage two of the field experiments planned under this PEER project will continue with regular evaluations of the animals and soil sampling as noted above. DNA will also be extracted from these samples for laboratory analysis. In view of the delays experienced on the project both at the outset and while in progress, a no-cost extension has been issued through September 2020. The ultimate goal will be to integrate the data from all components of the project to produce a final paper on the team’s major findings.
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