## 3 Results and Discussion
### Mechanism Involved in the Transmission of ARGs
#### 3.2.2 Correlations Between ARGs, LRGs and the Microbial Community  
ARGs in environmental microorganisms represented a crucial reservoir for human pathogens to acquire drug resistance, and the increased abundance of ARGs in such environments significantly heightens the risk of ARGs transmission to other bacteria and pathogens [34]. Correlation analyses demonstrated positive associations between the relative abundances of ARGs and several bacterial phyla, including Proteobacteria, Actinobacteria, Deinococcus-Thermus, and Chloroflexi (Figure S1). For instance, Proteobacteria was positively correlated with ARGs such as _aad_A2-01, _dr_A1, _flo_R, _mph_A-02, and _tet_D-01, which are implicated in metal resistance, motility, biofilm formation, and stress response. Similarly, Actinobacteria correlated with ARGs _mdt_A, _mex_F, and _tet_A-02, associated with antibiotic resistance and metabolic pathways. Key genera, including _Alishewanella_, _Roseomonas_, _Dietzia_, _Rubellinicrobium_, _Sphingomonas_, _Microella_, _Gp6_, _Gp4_, _Gp16_, _Gemmatomonas_, _Truepera_, and _Fontibacter_, were identified as potential hosts of various ARGs (e.g., _aad_D, _flo_R, _dr_A1, _mph_A-02, _me_F_A, _tet_B-02, and _su1_) (Figure S3). _Rubellinicrobium_ might be a potential host of _aad_D, _flo_R, and _dr_A1. _Hyphomonas_ might be a potential host of _mph_A-02, _me_F_A, and _tet_B-02. Additionally, _Gp16_ was suggested as a potential host for _Pbr_A, and _Truepera_, _Roseomonas_, _Fontibacter_, _Alishewanella_, or _Gp6_ for _2 nt_A. The density of ARG-hosting bacteria was critical for ARG transfer, with lower host abundance reducing horizontal gene transfer via limited bacterial encounters [35]. LRGs were similarly associated with distinct bacterial. _Znt_A abundance correlated positively with _Actinobacteria_, while _Pbr_T was linked to _Acidobacteria_, _Chloroflexi_, and _Plancotomycetes_. _Pbr_A showed positive correlations with _Acidobacteria_, _Actinobacteria_, and _Chloroflexi_, and _Cad_A with _Acidobacteria_ and _Plancotomycetes_. ARGs, often found on mobile genetic elements such as transposons and plasmids, exhibited positive correlations with dominant bacterial genera, aligning with dominant genera. [PERSON] et al. [36] found that resistance in _Firmicutes_ can spread rapidly via plasmid-mediated gene transfer. _Znt_A was positively correlated with _Sphingomonas_, _Gaiella_, _Blastococcus_, _Microwiga_, _Gemmatomonas_, and _Rubellinicrobium_, while _Pbr_T correlated with _Gp16_ and _Mycobacterium_. _Pbr_A correlated with _Gp16_, _Blastococcus_, _Gp6_, _Microwiga_, and _Gemmatomonas_, while _Cad_A was associated with _Gp6_, _Gp4_, and _Microwiga_. These findings indicated the crucial role of microbial community composition in shaping the distribution of ARGs and LRGs. Elevated heavy metal concentrations not only increased the abundance of MRGs but also induced shifts in ARGs prevalence [37]. The relative abundances of _Cad_A, _Pbr_A, and _Pbr_T were negatively correlated with most ARGs, while _Znt_A was positively correlated with numerous ARGs, indicating that Pb contamination influences both _Znt_A and ARGs expression. _Cad_A was positively correlated with _ceo_A, _Pbr_A with _aad_D and _acr_R-01, and _Pbr_T, _flo_R, _mec_A, _su1_, and _su2_. where _su2_ was significantly correlated. _Znt_A was positively correlated with _blq_PSE, _blq_TEM, _mef_A, _tet_B-02, _tet_D-01, _tet_D-01, _tet_Q, and _tet_S, with particularly strong associations for _blq_TEM and _tet_Q. Potential hosts for _Znt_A, such as _Truepera_, _Roseomonas_, _Fontibacter_, _Alishewanella_, and _Gp6_, also correlated with ARGs like _blq_TEM, _tet_B-02, _tet_O-01, and _tet_Q. Additionally, _Pbr_A may regulate _acr_R-01, while _Pbr_T may influence the expression of _flo_R, _mec_A, and _su1_, suggesting Pb contamination promoted ARGs co-selection, leading to concurrent changes in both ARGs and LRGs. Changes in Pb concentration and pH significantly affect Pb bioavailability and the efficacy of bioremediation efforts.