Persistencia de bacterias entéricas resistentes y genes de resistencia a antibióticos en sustratos suplementados con gallinaza comercial y de compostaje tradicional

Abstract

The application of animal manure (fresh or composted) represents a common practice. This practice favors the increasing of organic matter into soils at reduced costs. The efficient use of the animal residues supporting the recycling of organic matter and nutrients. Compost practices transforms efficiently and safely animal manure into materials suitable for use into agricultural soils. However, the application of traditional practices to compost fertilizers, consisting of simple drying of the animal manure and later applying it directly to the soil is common. The high levels of enteric bacteria present in these matrices may represent a pathway for the spread of pathogenic organisms, which can potentially integrate within the food chain.

For this reason, the persistence of enteric bacteria (heterotrophic bacteria, E. coli, coliforms) resistant to antibiotics and the persistence of antibiotic resistance genes were evaluated in soils supplemented with two types of fertilizer (compost of animal origin traditionally composted and compost of animal origin processed by the industry) during 111 days; determining that the application of these fertilizers notably increases the densities of resistant enteric bacteria (ARBs) and antibiotic resistance genes (ARGs) in soils. These pollutants have a high persistence over time, which suggests that the application of fertilizers of animal origin, especially when they do not receive appropriate treatment, may represent a pathway for the spread of antibiotic resistance determinants throughout the chain. foo