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Metal(loid)s can increase the spread and enrichment of antibiotic resistance in the environmental system by means of a co-selection effect. The effects of introducing antibiotics into the environment on the long-term resistance of microbial communities to metal(loid)s are largely unknown. Here, manure-fertilizers that contained either oxytetracycline (OTC) or sulfadiazine (SD) at four concentrations (0, 1, 10, and 100 mg kg−1) were incorporated into a maize cropping system in an area with a high arsenic geological background. The results showed that the introduction of exogenous antibiotics had a notable effect on the bacterial diversity of the maize rhizosphere soil, as evidenced by alterations in Chao1 and Shannon index values when compared to those of the control. Oxytetracycline exposure did not significantly alter the prevalence of most bacterial phyla, with the exception of Actinobacteria. However, sulfadiazine antibiotic exposure caused a decrease in prevalence as exposure concentrations increased, with the exception of Gemmatimonadetes. The same reaction pattern was observed in the five most prevalent genera, such as Gemmatimonas, Fulvimonas, Luteimonas, Massilia, and Streptomyces. It was observed that the abundance of tetC, tetG, and sul2 antibiotic resistance genes (ARGs) significantly increased in correlation with the concentration of antibiotic exposure, and a strong link was found between these genes and integrons (intl1). The abundance of microbial functional genes related to arsenic transformation (aioA and arsM) increased when there was an increase in oxytetracycline exposure concentrations, whereas a decrease in abundance was observed with increasing sulfadiazine exposure concentrations. Proteobacteria, Actinobacteriota, Acidobacteriota, Chloroflexi, Firmicutes, Bacteroidota, Gemmatimonadota, Cyanobacteria and Planctomycetes were found to be important indicators of the introduction of antibiotics, and may be essential in the development of antibiotic resistance in soils with high arsenic geological background. Planctomycetacia (from Planctomycetes) was significantly negatively correlated with sul2 and intl1 genes, which might play a role in the development of resistance profiles to exogenous antibiotics. This study will expand our understanding of microbial resistance to antibiotic contamination in areas with a high geological background, as well as reveal the hidden ecological effects of combined contamination. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the long-time behavior of g -Navier-Stokes equations with weak dampnesss and time delay. The uniformly attracting sets of processes are obtained. On the basis of the method with asymptotic compactness, the existence of the uniform attractor for the equation is proved with the restriction of the forcing term belonging to translational compacted function space. [ABSTRACT FROM AUTHOR]

The residual patterns of 23 target antibiotics in five classes of compound in catchment sediments of a rapidly urbanizing city in east China were studied. A total of 14 antibiotics were detected in the catchment. The dominant classes were tetracyclines and fluoroquinolones and these occurred at substantial concentrations. High environmental risk at the sites sampled may be associated with antibiotics detected at high concentrations. For example, at one site chlortetracycline was found to occur at concentrations ≤ 4496 ng/g. Source traceability indicates that high intensity of urbanization (e.g. hospitals and livestock farms) had a high spatial relationship with sites of high antibiotic contaminations. Urban and suburban areas had some impacts on antibiotic residues in the catchment, especially on veterinary antibiotics such as chlortetracycline in suburban areas. Moreover, antibiotics detected at high concentrations in urban areas included fluoroquinolones associated with human medicine. [ABSTRACT FROM AUTHOR]

Xijiang River is the main surface water source in Guangxi province, South China. This study was carried out to investigate the distribution and potential ecological risks of seven heavy metals (Cu, Pb, Zn, As, Cd, Ni, and Cr) in surface sediments in Xijiang River basin. The results illustrated that the average concentrations of Zn, Pb, Cd, Cu, As, Ni, and Cr were 483.9, 207.5, 13.35, 23.50, 312.1, 28.75, and 50.62 mg/kg, respectively. Among them, Zn, Pb, Cd, and As were the major heave metals with concentration exceeding Class 3 threshold value of Chinese national standard. The result also showed samples with high ecological risk were mainly located in the upstream of Xijiang River basin as Diaojiang River, Hongshui River, Jincheng River, and Dahuan River. Based on the pollution risk assessment, the area manifested composite pollution of heavy metals in the sediments, signifying As, Pb, and Cd as the dominant heavy metals, and there were high ecological risk in sediments for these metals. According to correlation matrix and factor analysis (FA), the seven heavy metals were divided into three types/classes, Cd, as and Zn attributed by anthropogenic sources, natural sources corresponds for Ni and Cr while both natural and anthropogenic sources were attributed to Cu. [ABSTRACT FROM PUBLISHER]