Persistencia de genes de resistencia a antibióticos e indicadores de contaminación fecal durante el compostaje tradicional de gallinaza

Abstract

Globally, the livestock industry represents the principal consumer of antibiotics, mainly used to prevent, and treat animal infections. Composted animal manure is one of the most principal resources used by organic farmers because it represents an ideal nutrient source for farming soils. It has been found that hen manure contains a large number of bacteria resistant to (ARBs) antibiotics and resistant-genes to (ARGs) antibiotics. This research project assessed the persistence of antibiotic resistance genes (sul1, blaTEM, qnrS, ermB, and tetW), through quantitative PCR (qPCR) and gene 16S rDNA in hen manure composting samples during 49 days; the most abundant gene was the blaTEM beta-lalatamic resistance gene in the TI (non-additive) T2 (cal) and T4 (bacteria) treatments; while the T3 (tamo) treatment was the qnrS gene, indicators of fecal contamination were also evaluated during the same time, In the case of E.coli there was raised resistance until day 21, total coliforms has high densities microorganisms and resistance until day 28; while bacteriophages showed high resistance that surpassed the 49 days of composting. Consequently, this project establishes that poultry manure has resistance genes in several composing treatments and high densities of bacteriophages affecting the environment, which deserves precedence attention and complementary research in the use of organic fertilizers.