Pollution profiles of antibiotic resistance genes associated with airborne opportunistic pathogens from typical area, Pearl River Estuary and their exposure risk to human

https://doi.org/10.1016/j.envint.2020.105934Get rights and content
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Highlights

  • Bioaerosol amount showed site- and season-related variation in Pearl River Estuary.

  • The abundance and diversity of airborne pathogenic bacteria was higher than fungi.

  • Of the 21 airborne ARGs detected, tetA and tetB were found to be the most abundant.

  • Airborne opportunistic pathogens shaped the profile of the airborne ARGs.

  • Higher human daily intake of airborne ARGs was found in summer.

Abstract

To reveal the selective pressures of near-shore human activities on marine and continental bioaerosols, the pollution profile and potential exposure risk of airborne pathogens and antibiotic-resistance genes (ARGs) in Pearl River Estuaries (113.52 oE, 22.69 oN), a transitional zone between marine and continental environments, were fully explored. The results showed that the total bacteria among bioaerosols varied largely with average pollution levels of 1.86 × 105 and 4.35 × 104 cfu m−3 in spring and summer, respectively, and were high than those of airborne fungi. The predominant aerodynamic diameters of bioaerosols were in respirable size range (<4.7 µm), and the microbes communities’ diversity and abundance varied significantly. Besides, many opportunistic pathogenic bacteria (Burkholderia-Paraburkholderia, Staphylococcus and Acinetobacter) and fungi (Alternaria, Penicillium and Cladosporium) were dominant in bioaerosol samples. Of 21 ARGs subtypes detected, the tetracycline resistance gene tetA was the most abundant, followed by aminoglycoside resistance gene and mobile genetic elements. Correlation analysis revealed that the changes of pathogens community contributed significantly to the prevalence of ARGs in bioaerosol. Based on the average daily dose rates of microorganisms and human direct intake of ARGs, health risk of bioaerosols from the Pearl River Estuaries were also evaluated. In summary, the presence of opportunistic pathogens and diversity of ARGs strengthens the call to consider the bioaerosol in air quality monitoring and risk assessment in the future.

Keywords

Bioaerosols
Airborne antibiotic resistance genes
Airborne pathogens
Bacterial and fungal community
Exposure risk

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