Particle-size stratification of airborne antibiotic resistant genes, mobile genetic elements, and bacterial pathogens within layer and broiler farms in Beijing, China

• Published in: Environmental science and pollution research international Vol. 30; no. 52; pp. 112799 - 112812
• Main Authors: Bai, Yuqiao, Sun, Xingbin, Guo, Yajie, Qiu, Tianlei, Xin, Huibo, Yu, Aoyuan, Wang, Xuming, Gao, Min
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2023; Springer Nature B.V
• Subjects: Actinobacteria; air; Animals; Anti-Bacterial Agents; Antibiotic resistance; Antibiotics; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Bacteria - genetics; Bacteroidetes; Beijing; Campylobacter; chickens; Chickens - genetics; China; droplets; E coli; Earth and Environmental Science; Ecotoxicology; Environment; Environmental behavior; Environmental Chemistry; Environmental Health; Escherichia coli; Escherichia coli - genetics; Farms; Feces; Genes; Genes, Bacterial; Health risk assessment; Health risks; Humans; Interspersed Repetitive Sequences; Livestock; Microbial activity; microbiome; Microbiomes; Microorganisms; Occupational health; occupational health and safety; Particle mass; Particle Size; Particle size distribution; Particulates; pathogens; Poultry farming; Relative abundance; Research Article; Risk taking; RNA, Ribosomal, 16S - genetics; rRNA 16S; Size distribution; Staphylococcus; Stratification; Sulfonamides; Waste Water Technology; Water Management; Water Pollution Control; Beijing; Beijing China; China; Particle size distribution; Antimicrobial resistance; Chicken farms; Airborne transmission; Particulate attachment of microbes
• DOI: 10.1007/s11356-023-29975-8
• ISSN: 1614-7499; 0944-1344

The particle-size distribution of antimicrobial resistant (AMR) elements is crucial in evaluating their environmental behavior and health risks, and exposure to the fecal microbiome via particle mass (PM) is an important route of transmission of AMR from livestock to humans. However, few studies have explored the association between air and fecal AMR in farm environments from the perspective of particle-size stratification. We collected feces and PMs of different sizes from layer and broiler farms, quantified antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and human pathogenic bacteria (HPB) using Droplet digital PCR (ddPCR), and analyzed the bacterial communities based on 16S rRNA sequencing. The particle-size distributions of 16S rRNA and AMR elements were similar and generally increased with larger particle sizes in chicken farms. In broiler farms, we observed a bimodal distribution with two peaks at 5.8–9.0 μm and 3.3–4.7 μm. The dominant airborne bacterial phyla were Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes. The dominant phyla in the feces were the same as those in the air, but the order of relative abundance varied. The particle-size distributions of specific bacterial genera differed between the animal-farm types. Overall, the degree of association between feces and different particulates increased with increasing particle size. The microbial communities in the coarse particles were similar to those in fecal samples. Escherichia coli, Staphylococcus spp ., Campylobacter spp . , and sul 2 (sulfonamide ARGs) tended to attach to small particles. We highlight the particle size-specific relationship between fecal and air microbes involving ARGs, MGEs, and HPB and provide valuable information for comprehensively assessing the transmission of fecal microorganisms through the airpath and its environmental and occupational health risks.