School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, China.
College of Agronomy, Hunan Agricultural University, Changsha, 410127, China.
Environ Res. 2024 Dec 15;263(Pt 2):120090. doi: 10.1016/j.envres.2024.120090. Epub 2024 Oct 5.
Antibiotic resistance genes (ARGs) have been identified as emerging contaminants, raising concerns around the world. As environmentally friendly bioagents (BA), plant growth-promoting rhizobacteria (PGPR) have been used in agricultural systems. The introduction of BA will lead to the turnover of the microbial communities structure. Nevertheless, it is still unclear how the colonization of the invaded microorganisms could affects the rhizosphere resistome. Consequently, 190 ARGs and 25 integrative and conjugative elements (ICEs) were annotated using the metagenomic approach in 18 samples from the Solanaceae crop rhizosphere soil under BA and conventional treatment (CK) groups. Our study found that, after 90 days of treatment, ARG abundance was lower in the CK group than in the BA group. The results showed that aminoglycoside antibiotic resistance (OprZ), phenicol antibiotic resistance (OprN), aminoglycoside antibiotic resistance (ceoA/B), aminocoumarin antibiotic resistance (mdtB) and phenicol antibiotic resistance (MexW) syntenic with ICEs. Moreover, in 11 sequences, OprN (phenicol antibiotic resistance) was observed to have synteny with ICEPaeLESB58-1, indicating that the ICEs could contribute to the spread of ARGs. Additionally, the binning result showed that the potential bacterial hosts of the ARGs were beneficial bacteria which could promote the nutrition cycle, such as Haliangium, Nitrospira, Sideroxydans, Burkholderia, etc, suggesting that bacterial hosts have a great influence on ARG profiles. According to the findings, considering the dissemination of ARGs, BA should be applied with caution, especially the use of beneficial bacteria in BA. In a nutshell, this study offers valuable insights into ARGs pollution control from the perspective of the development and application of BA, to make effective strategies for blocking pollution risk migration in the ecological environment.
抗生素耐药基因（ARGs）已被确定为新兴污染物，引起了全球关注。作为环保型生物制剂（BA），植物促生根际细菌（PGPR）已被应用于农业系统。BA 的引入将导致微生物群落结构的转变。然而，目前尚不清楚入侵微生物的定植如何影响根际抗药性。因此，我们采用宏基因组学方法在 BA 和常规处理（CK）组的 18 个茄科作物根际土壤样本中注释了 190 个 ARG 和 25 个整合子-转座子（ICEs）。我们的研究发现，经过 90 天的处理，CK 组中的 ARG 丰度低于 BA 组。结果表明，与 ICEs 相关的氨基糖苷类抗生素耐药（OprZ）、青霉素类抗生素耐药（OprN）、氨基糖苷类抗生素耐药（ceoA/B）、氨基香豆素类抗生素耐药（mdtB）和青霉素类抗生素耐药（MexW）。此外，在 11 个序列中，观察到 OprN（青霉素类抗生素耐药）与 ICEPaeLESB58-1 具有基因同线性，表明 ICEs 可能有助于 ARG 的传播。此外，分箱结果表明，ARG 的潜在细菌宿主是有益细菌，它们可以促进营养循环，如 Haliangium、Nitrospira、Sideroxydans、Burkholderia 等，这表明细菌宿主对抗生素耐药基因图谱有很大的影响。根据研究结果，考虑到 ARGs 的传播，BA 的应用应谨慎，特别是在 BA 中使用有益细菌时应更加谨慎。总之，本研究从 BA 的开发和应用角度出发，为 ARGs 污染控制提供了有价值的见解，为阻断生态环境中污染风险迁移制定了有效的策略。
