Attenuation of antibiotic resistance genes in livestock manure through vermicomposting via Protaetia brevitarsis and its fate in a soil-vegetable system

https://doi.org/10.1016/j.scitotenv.2021.150781Get rights and content

Highlights

  • High ARGs level were found in livestock-amended soil-vegetable system.

  • Low spreading risk of ARGs was revealed in frass-amended soil-vegetable system.

  • Vermicomposting via Protaetia brevitarsis attenuated about 40% ARG subtypes.

  • MGEs were the key drivers influencing the ARGs pattern in frass-amended soil.

Abstract

Scarab larvae (Protaetia brevitarsis) could transform large quantities of agricultural waste into compost, providing a promising bio-fertilizer for soil management. There is an urgent need to assess the risk of antibiotic resistance genes (ARGs) in soil-vegetable system with application of compost derived from P. brevitarsis larvae. We conducted a pot experiment to compare the changes of ARGs in the soil and lettuce by adding four types of manure, livestock manure (chicken and swine manure) and the corresponding larval frass. Significantly low numbers of ARGs and mobile genetic elements (MGEs) were detected in both larval frass compared with the corresponding livestock manure. Pot experiment showed that the detected numbers of ARGs and MGEs in bulk soil, rhizosphere soil, and root endophytes were significantly lower in the frass-amended treatments than the raw manure-amended treatments. Furthermore, the relative abundance of ARGs and MGEs with application of chicken-frass was significant lower in rhizosphere soil and leaf endophyte. Using non-metric multidimensional scaling analysis, the patterns of soil ARGs and MGEs with chicken-frass application were more close to those from the bulk soil in the control. Structural equation models indicated that livestock manure addition was the main driver shaping soil ARGs with raw manure application, while MGEs were the key drivers in frass-amended treatments. These findings demonstrated that application of livestock manure vermicomposting via scarab larvae (P. brevitarsis) may be at low risk in spreading manure-borne ARGs through soil-plant system, providing an alternative technique for reducing ARGs in organic waste.

Introduction

Land application of livestock manure is a common waste process that improves soil fertility and increases food production. However, with the widespread use of antibiotics in animal husbandry, concerns about the antibiotic residues and selective pressure on indigenous antibiotic resistance bacteria are gaining global attention. Accumulating evidence shows that animal manure has been identified as a significant contributor and reservoir of antibiotic resistance genes (ARGs) (Barrios et al., 2021; Leclercq et al., 2016). Previous studies indicated that land application of animal manure without well treatment resulted in a significant rise in the diversity and abundance of ARGs (Zhu et al., 2013; Zhou et al., 2019), posing a potential risk of spreading antibiotic resistance in environment. Understanding the pathway of ARGs dissemination via soil and plant will be necessary for assessing the potential spread of antibiotic resistome in manure.

It has been suggested that ARGs may be transferred from atmosphere aerosol to the plant surface via the external pathway, or through the plant tissues via the internal pathway from manure-amended soils to plants, resulting in a higher degree of ARGs in edible parts (Marti et al., 2013; Chen et al., 2017; Zhu et al., 2017; Zhang et al., 2019). As a result, manure-derived ARGs may enter into the food chain, posing a risk to human health via consuming raw vegetables or direct contact (Rossi et al., 2014; Udikovic-Kolic et al., 2014; Chen et al., 2019). Recent studies have identified a few core microbiota presented across all plant tissues including rhizosphere and phyllosphere (Chen et al., 2021), indicating the capacity of manure-borne ARGs transmission from soil to plant. It is therefore imperative to develop effective strategies to reduce the dissemination risk of ARGs derived from manure for safer utilization of animal manure as fertilizer.

Strategies have been devoted to deal with the manure derived from livestock feedlots like vermicomposting, which is considered as a low-cost and sustainable bio-conversion process for animal manure recycling with potential attenuation capacity in ARGs (Zhang et al., 2012; Bhat et al., 2018; Xia et al., 2019). Vermicomposting via saprophagous fauna, such as earthworms and housefly larvae, resulted in a substantial reduction in the relative abundance of ARGs (Wang et al., 2015a; Wang et al., 2017; Cui et al., 2018; Chao et al., 2019; Liu et al., 2020). The extent to which manure is reduced more efficiently depends on manure type and fauna species (Miranda et al., 2021). Scarab larvae, such as Protaetia brevitarsis, as one of the typical saprophagous faunas, has the ability in digesting organic waste and thus improving soil fertility and sustainability (Ahrens et al., 2014; Wang et al., 2019). P. brevitarsis larva is a common soil insect, feeding on a wide range of organic resources (Li et al., 2019). We therefore hypothesized that the abundance of ARGs in the compost from P. brevitarsis larvae may be reduced, while the fate of frass-derived ARGs in soil-vegetable system remains unknown.

In this study, we investigated the change of ARGs in swine and chicken manure during one-week vermicomposting via scarab larvae as well as the fate of ARGs in the soil-vegetable system through a pot experiment using high-throughput qPCR and Illumina sequencing technique. We aimed to (i) compare the change of ARGs in swine and chicken manures vermicomposting via P. brevitarsis larvae; (ii) assess the impacts of frass application on the spread of ARGs in lettuce. These findings would provide a practical ARGs mitigation approach for livestock manure and highlight their potential risks in soil-vegetable system.

Section snippets

Soil sampling and livestock manure preparation

Soil sampling sites were located at Xingtai county (XT) (27°15′ N, 113°54′ E) and Changfeng county (CF) (28°13′ N, 113°30′ E) in Hunan province, China. These two soils developed from quaternary red earth were collected in April 2018. Five points at top layers (0–20 cm) within each land were taken and mixed into one composite sample as described previously (Zhao et al., 2020). Soil samples were air dried and passed through a 5-mm mesh for the subsequent pot experiment. Swine manure was collected

Changes of ARGs and bacterial community from livestock manure to larval frass

A total of 234 ARGs and 10 MGEs were detected in the livestock manure and larval frass. The detected numbers of ARGs and MGEs in initial swine and chicken manure were both significantly higher than those in the frass (Fig. 1a and b). Venn diagrams showed that 82 and 93 ARG and MGE subtypes were removed from the initial swine and chicken manure samples, respectively. The detected unique ARGs and MGEs numbers in frass samples were significantly lower than those in initial manure samples (Fig. 1c

Attenuation of ARGs in manure through larvae conversion

In this study, frass samples had a significant lower number of ARGs than raw manure samples, indicating that the scarab larva has a great potential in reducing manure-borne ARGs through vermicomposting. Previous studies have found that high efficiency in ARGs attenuation by earthworms and housefly larvae, which further confirmed that vermicomposting has its priority in reducing ARGs compared with traditional composting practice (Wang et al., 2015a). Our previous research has suggested that

Conclusions

In summary, the relative abundance and numbers of ARGs in livestock manure was significantly attenuated through vermicomposting via P. brevitarsis larvae, resulting in a low risk for land application. It has been widely acknowledged that livestock manure vermicomposting via earthworms or housefly larvae may be an ecofriendly technique and is widely applied in industrial sludge treatment and municipal solid waste treatment (Soobhany, 2018; Swati and Hait, 2018). The addition of frass in pot

CRediT authorship contribution statement

Xiang Zhao: Conceptualization, Methodology, Investigation, Formal analysis, Writing – original draft, Visualization. Ju-Pei Shen: Conceptualization, Validation, Formal analysis, Writing – review & editing, Supervision, Project administration. Chang-Long Shu: Conceptualization, Resources. Sheng-Sheng Jin: Methodology, Resources. Hong J. Di: Writing – review & editing. Li-Mei Zhang: Conceptualization, Validation. Ji-Zheng He: Conceptualization, Validation, Writing – review & editing, Supervision,

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This work was financially supported by National Key Research and Development Program of China (2017YFD0801500 and 2017YFE0109800), and National Natural Science Foundation of China (32070511). Many thanks for Dr. Phillip Chalk from Melbourne University for their helpful comments on this manuscript.

References (54)

  • Y. Li et al.

    Protaetia brevitarsis larvae can efficiently convert herbaceous and ligneous plant residues to humic acids

    Waste Manag.

    (2019)
  • C. Liu et al.

    Changes in gut bacterial communities and the incidence of antibiotic resistance genes during degradation of antibiotics by black soldier fly larvae

    Environ. Int.

    (2020)
  • C.D. Miranda et al.

    Black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), and house fly, Musca domestica L. (Diptera: Muscidae), larvae reduce livestock manure and possibly associated nutrients: an assessment at two scales

    Environ. Pollut.

    (2021)
  • F. Rossi et al.

    Horizontal gene transfer among microorganisms in food: current knowledge and future perspectives

    Food Microbiol.

    (2014)
  • N. Soobhany

    Preliminary evaluation of pathogenic bacteria loading on organic municipal solid waste compost and vermicompost

    J. Environ. Manag.

    (2018)
  • J.Q. Su et al.

    Functional metagenomic characterization of antibiotic resistance genes in agricultural soils from China

    Environ. Int.

    (2014)
  • F.H. Wang et al.

    Antibiotic resistance genes in manure-amended soil and vegetables at harvest

    J. Hazard. Mater.

    (2015)
  • H. Xia et al.

    Effects of tetracycline residuals on humification, microbial profile and antibiotic resistance genes during vermicomposting of dewatered sludge

    Environ. Pollut.

    (2019)
  • W.Y. Xie et al.

    Long-term effects of manure and chemical fertilizers on soil antibiotic resistome

    Soil Biol. Biochem.

    (2018)
  • Z.J. Zhang et al.

    Swine manure vermicomposting via housefly larvae (Musca domestica): the dynamics of biochemical and microbial features

    Bioresour. Technol.

    (2012)
  • Y.J. Zhang et al.

    Transfer of antibiotic resistance from manure-amended soils to vegetable microbiomes

    Environ. Int.

    (2019)
  • X. Zhao et al.

    Arsenic and cadmium as predominant factors shaping the distribution patterns of antibiotic resistance genes in polluted paddy soils

    J. Hazard. Mater.

    (2020)
  • X. Zhou et al.

    Turning pig manure into biochar can effectively mitigate antibiotic resistance genes as organic fertilizer

    Sci. Total Environ.

    (2019)
  • S.Y.D. Zhou et al.

    Does reduced usage of antibiotics in livestock production mitigate the spread of antibiotic resistance in soil, earthworm guts, and the phyllosphere?

    Environ. Int.

    (2020)
  • B.K. Zhu et al.

    Does organically produced lettuce harbor higher abundance of antibiotic resistance genes than conventionally produced?

    Environ. Int.

    (2017)
  • D. Ahrens et al.

    The evolution of scarab beetles tracks the sequential rise of angiosperms and mammals

    Proc. Biol. Sci.

    (2014)
  • J.G. Caporaso et al.

    QIIME allows analysis of high-throughput community sequencing data

    Nat. Methods

    (2010)
  • Cited by (13)

    • Persistence of Salmonella Typhimurium and antibiotic resistance genes in different types of soil influenced by flooding and soil properties

      2022, Ecotoxicology and Environmental Safety
      Citation Excerpt :

      MGEs are frequently regarded as the primary route for spreading ARGs (Gillings, 2014). Studies reported that MGEs were the key driver shaping ARGs profiles in frass-amended soil (Zhao et al., 2022), in the Yellow River and tap water (Yu et al., 2022), or played a predominant role in ARG removal rate during chicken manure composting (Zhou et al., 2021; Qiu et al., 2022). However, it is important to note that ARGs might be found on the DNA segment of MGEs (Qian et al., 2018).

    • Different ratios of Canna indica and maize–vermicompost as biofertilizers to improve soil fertility and plant growth: A case study from southwest China

      2022, Environmental Research
      Citation Excerpt :

      Furthermore, the different wetland plant-based vermicomposts used as organic treatments in the present study resulted in different compositions of soil nutrients. Zhao et al. (2022) reported the importance of vermicomposting Protaetia brevitarsis on antibiotic resistance genes in soil–vegetable systems. However, field experiments and long-term crop growth monitoring would provide a better understanding of vermicomposting systems with wetlands plants.

    • Application of wetland plant-based vermicomposts as an organic amendment with high nutritious value

      2022, Process Safety and Environmental Protection
      Citation Excerpt :

      Besides, in the present study, different wetland plant vermicomposts were used as organic treatments, resulting in differences in the extent of soil nutrient enrichment, and varied regarding different nutrients. Notably, the research was limited to pot experiments as reported by Zhao et al. (2022) about importance of vermicomposting by Protaetia brevitarsis for antibiotic resistance genes in soil-vegetable system, and subsequent field experiment with microbial and molecular studies and long-term crop rotations in other regions for growth tracking would be more helpful to evaluate the effects and prospects of wetland plant vermicomposts. In the present study, wetland plant residues and manure (ecological waste) as raw materials were reused for vermicomposting, thereby proposing a new sustainable management pattern.

    • Reuse of agricultural wastes, manure, and biochar as an organic amendment: A review on its implications for vermicomposting technology

      2022, Journal of Cleaner Production
      Citation Excerpt :

      Earthworms degrade cellulose more rapidly than other organisms, which partially explains the higher degradation rate (Chen et al., 2022). Zhao et al. (2022) used vermicomposting as an advanced technique because the application of livestock manure vermicomposting via scarab larvae (P. brevitarsis) may be at low risk in spreading manure-borne antibiotic resistance genes (ARGs) through the soil plant system, providing an alternative technique for reducing ARGs in organic waste. Developing nations must set up resource reuse and recycling so that resources can be preserved, reused, and recycled rather than discarded (Bui et al., 2021).

    • Manure application: A trigger for vertical accumulation of antibiotic resistance genes in cropland soils

      2022, Ecotoxicology and Environmental Safety
      Citation Excerpt :

      In this study, we tracked the vertical migration of ARGs in farmland soil using swine manure, and found that manure-fertilization promoted the accumulation of ARGs in farmland soil, increasing the ecological risk to the agricultural environment. The risks associated with this fertilization are twofold: the migration of ARGs in the soil-vegetable system (Li et al., 2021; Zhao et al., 2021), and the harm to soil quality due to the gradual accumulation of ARGs in deep soil (Li et al., 2020a; Liu et al., 2021a). The results of this study showed that the ARG abundance s in three pieces topsoil with swine manure application was significantly higher than that of not applying swine manured soil (Fig. 1).

    View all citing articles on Scopus
    View full text