Microorganisms Control in Animal Effluents- A One Health Approach
Author(s): Ana Sofia Pereira Carvalho Soares, Carla Isabel da Silva Miranda, Henrique Manuel da Fonseca Trindade, Ana Cláudia Correia Coelho
Abstract: Utilization of organic manures such as cow slurry is the most economic, practical, environmentally beneficial and useful option for improving soil quality and fertility. In the specific case of land-spreading of bovine manure, that is a common fertilization practice, this effluent is recognised to contain human pathogenic bacteria, which may persist for several weeks in soil, so this practise needs to be done correctly. Spreading fresh manures directly to land presents complex risks in many levels, including a higher risk of pathogen transfer to the food chain for example the liquid fraction of bovine slurry contains an important part of the total bacteria of slurry (>80%). This information was being used during the years to improve guidelines on the management of manures to minimise the risks of pathogen transfer from animal effluents to the human food chain or water systems. The effectiveness of manure management systems needs to concern environmental transmission pathways by which zoonotic pathogens presents in animal manures may be transported to the environment. So, these management systems are planned to reduce the concentrations of microbes found in manure (by 90 to 99% or more). Antibiotics used in farms are excreted by the animals and end up in their effluents, being animal effluents (manure or slurry) used as fertilizers, the antibiotics residues will be transferred to the soil and in some cases can contaminate ground water. With the amount of slurry applied on the soils as fertiliser every year, there is a need of studies to measure the leaching of pathogenic agents, antibiotics residues normally present in slurry, and their fate in the environment using for that a One Health approach. This manuscript is a review of the scientific literature on the viability of some microorganisms in animal effluents and the effects of different manure treatments on the microbial concentrations.