Transmission of antibiotic resistance through organic amendments in arable land: A 3-year field study with pigeonpea–wheat cropping system

• Published in: Journal of hazardous materials 2024-06, Vol.471, p.134378, Article 134378
• Main Authors: Shrivas, Vijay Laxmi, Choudhary, Anil K., Hariprasad, P., Sharma, Shilpi
• Format: Article
• Language: English
• Subjects: Agriculture; Anti-Bacterial Agents - pharmacology; Antibiotic resistance genes; Bio-compost; Cajanus - genetics; Crops, Agricultural; Drug Resistance, Microbial - genetics; Farming practices; Farmyard manure; Genes, Bacterial; Integrons - genetics; Manure - microbiology; Organic Agriculture; Pigeonpea-wheat cropping system; Soil - chemistry; Soil Microbiology; Triticum - genetics
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2024.134378

The worldwide emergence of antimicrobial resistance (AMR) poses a substantial risk to human health and environmental stability. In agriculture, organic amendments (derived from organic sources such as manure, and plant residues) are beneficial in restoring soil properties and providing essential nutrients to crops but raise concerns about harboring antibiotic resistance, which emphasizes the need for vigilant monitoring and strategic interventions in their application. The current study assessed the impact of farming practices (organic and conventional) in a three-year field experiment with pigeonpea-wheat cropping system, focusing on the transmission of AMR using culture-dependent and -independent approaches, and soil nutrient content. Markers for antibiotic resistance genes (ARGs) (aminoglycoside-aacA, β-lactam-blaTEM, chloramphenicol-cmlA1, macrolide-ermB, sulfonamides-sul1, sul2, and tetracycline-tetO) and integrons (intl1 and intl2) were targeted using qPCR. Manure amendments, particularly FYM1, exhibited a higher abundance of copies of ARGs compared to the rhizospheric soil. Organic farming was associated with higher copies of intl2, sul1, blaTEM, and tetO genes, while conventional farming showed increased copies of sul2 and ermB genes in the rhizosphere. Significant positive correlations were observed among soil nutrient contents, ARGs, and MGEs. The notable prevalence of ARGs linked to manure amendments serves as a cautionary note, demanding responsible management practices. [Display omitted] •Multi-drug-resistant bacteria prevalent in majority of manure samples.•Higher ARB in manure treatments than biocompost, latter reduced CFU over 3 years.•Abundance of ARB and ARGs decreased over the course of 3-year experiment.•Higher intl2, sul1, blaTEM, and tetO copies observed under organic farming.•Positive correlations between available NPK and SOC content with ARG copies.