[Distribution of Antibiotic Concentration in Domestic Wastewater Treatment Facilities in Villages and Towns].

Antibiotics discharged into the environment cause increased environmental resistance. Four types of antibiotics (quinolones, tetracyclines, macrolides, and ß-lactams) were selected for this study. In a comparison with the municipal wastewater plant, the concentration and removal of antibiotics in influent and effluent of domestic wastewater treatment facilities of different scales in villages and towns was investigated using high-performance liquid chromatography (HPLC) and tandem mass spectrometry (MS). The results showed that the highest amount of ofloxacin in rural wastewater treatment facilities reached 32663.5 ng·L-1. Due to the different situations of influent fluctuation, discharge requirements, and management between urban and rural wastewater plants, only 33% of the rural domestic wastewater facilities detected an antibiotics removal rate of more than 60%. The effective removal of some antibiotics can be achieved when the rural domestic wastewater treatment facilities maintain the standard discharge of conventional pollutants.

An MRI-Compatible Foot-Sole Stimulation System Enabling Characterization of the Brain Response to Walking-Related Tactile Stimuli.

Foot-sole somatosensory impairment is a main contributor to balance decline and falls in aging and disease. The cortical networks involved in walking-related foot sole somatosensation, however, remain poorly understood. We thus created and tested a novel MRI-compatible device to enable study of the cortical response to pressure stimuli applied to the foot sole that mimic those stimuli experienced when walking. The device consists of a dual-drive stimulator equipped with two pneumatic cylinders, which are separately programed to apply pressure waveforms to the entire foot sole. In a sample of nine healthy younger adults, the pressure curve applied to the foot sole closely correlated with that experienced during over ground walking (r = 0.811 ± 0.043, P < 0.01). MRI compatibility testing indicated that the device has no or negligible impact on MR image quality. Gradient-recalled echo-planar images of nine healthy young adults using a block-designed 3.5-min walking-related stimulation revealed significant activation within the supplementary motor area, supramarginal gyrus, paracingulate gyri, insula, precentral gyrus, middle temporal gyrus, and hippocampus (uncorrected P < 0.001, k ≥ 10). Together, these results indicate that this stimulation system is MRI-compatible and capable of mimicking walking-related pressure waveforms on foot sole. It may thus be used as a research tool to identify cortical targets for interventions (e.g., non-invasive brain stimulation) aimed at enhancing this important source of input to the locomotor control system.

Screening and quantitation of residual antibiotics in two different swine wastewater treatment systems during warm and cold seasons.

Due to many occurrences of the illegal addition, misuse and abuse of antibiotics in the swine industry in China, high-resolution mass spectrometry (HRMS) was used to screen and identify these materials in two swine wastewater treatment systems (Swine farm 1: anaerobic digestion - lagoon treatment; Swine farm 2: anaerobic digestion - anoxic treatment - aerobic biological treatment). The results showed that 11 out of 115 antibiotics, including tetracyclines (tetracycline, oxytetracycline, chlortetracycline), sulfonamides (sulfadimidine (SDMD)), macrolides (clarithromycin, tilmicosin (TILM)), fluoroquinolones (ciprofloxacin, ofloxacin, enrofloxacin), ß­lactam (penicillin G), and lincosamides (lincomycin), were identified in the swine farms by screening and confirmation methods through HRMS. The quantification method was carried out using triple-quadrupole tandem mass spectrometry, and the recoveries of 11 analytes in the swine wastewater were above 50%. The investigation results showed that the amount of antibiotic residues during the cold season was much higher than that during the warm season. Among the antibiotics, tetracyclines (average of 58%) were the main antibiotic residues in the two swine farms, with TILM second (33%). Sulfonamides (SDMD) existed only in SF1 and accounted for 10% of the total antibiotic concentration. The average proportion of total antibiotics in the solid and liquid phases were 98.5% and 1.5%, respectively, indicating that antibiotics were mainly adsorbed onto solids, though only SDMD remained relatively high in the liquid phase (5.29%). The degradation data of most of the antibiotics detected in the liquid phase during the wastewater treatments well fitted the simple first-order kinetic model in both SF1 and SF2, and the half-lives of the analytes in SF2 were much shorter than those in SF1. After the wastewater treatment process, approximately 80% of the antibiotics could be removed, but sulfonamides remained at a relatively higher percentage and were the main antibiotics in the effluent (approximately 60%).

Which animal type contributes the most to the emission of antibiotic resistance genes in large-scale swine farms in China?

Modern swine farms generally contain several animal types and rely extensively on the feed additives, including antibiotics and heavy metals, to augment animal growth. Nonetheless, as an important reservoir of antibiotic resistance genes (ARGs) in the environment, the ARGs emission of each animal type from swine farms has not been characterized. The goal of this study is to determine which animal type contributes the most to the ARGs emission into the environment in typical swine farms of China. Results showed that chlortetracycline (CTC), Cu and Zn were the typical feed additives, and the concentrations of antibiotics and heavy metals in the feed and swine manure were generally higher in nursery pigs (NP) than other animal types, while the gene copies of ARGs from gestation sows (GS) were the most abundant. GS released the most of antibiotics, ARGs and mobile genetic elements (MGEs) per head per day compared to other animal types. A typical swine farms with the feedstock of 10,000 pigs could release about 4.0±1.3×1017 gene copies of ARGs per day, and concerning the breeding ratio and manure production coefficient, growing and fattening pigs (GFP) released the most of ARGs and antibiotics, whereas gestation sows (GS) released the most of MGEs. The different distribution of ARGs in different animal types was mainly determined by the discrepancy of microbial community composition reflected by mantel test and partial redundancy analysis (pRDA). The dominant phylum in swine manure were Firmicutes and Bacteroidetes, but Proteobacteria, Bacteroidetes and Spirochaetae played the dominant role in shaping the ARGs profiles. Antibiotics and heavy metals could have generated and maintained the ARGs profiles, whereas the proliferation and spread of ARGs could be mainly attributed to microbial community in swine manure.

[Distribution and Treatment of Antibiotics in Typical WWTPs in Small Towns in China].

As a new, persistent pollutant in the environment, antibiotics are one of the most important pollutants in sewage treatment plants. The objective of this work was to investigate the concentration distribution and removal efficiency of antibiotics for three typical wastewater treatment technologies applied in small towns (CASS, A2/O, and Orbal oxidation ditch) using solid phase extraction-liquid chromatography-tandem mass spectrometry. Sixteen typical antibiotics, including four tetracyclines, three ß-lactams, four macrolides, three quinolones, and two sulfonamides, were analyzed in the influent and effluent. In addition, the relationship between the presence of antibiotics and the basic water quality (NH4+-N, TN, COD, pH, etc.) in the WWTPs was analyzed. The results showed that ofloxacin (OFX) and norfloxacin (NOR) were the main antibiotics in the WWTPs in this study. However, the concentrations of these two antibiotics in the effluent were low, indicating effective antibiotic removal efficiency. The antibiotic removal efficiency was higher than 60% in five of the WWTPs. Compared with the A2/O process, the CASS and Orbal oxidation ditch technologies resulted in higher removals of most of the antibiotics. In addition, the CASS and A2/O processes worked best for the removal of ß-lactam [ampicillin (AMP) and penicillin (PCN)], quinolones (ENR, NOR, and OFX), and macrolide (CLR), while the Orbal oxidation ditch worked best for the removal of tetracyclines (TC and OTC) and sulfonamides [sulfadiazine (SD)]. The correlation between antibiotic concentration and the basic parameters of water quality (NH4+-N, TN, COD, pH, etc.) was analyzed, and it was found that the water quality parameters had some effect on the concentration of antibiotics. With higher concentrations of the basic water quality parameters, higher the concentration of erythromycin (EM), roxithromycin (ROX), 4-epi-Tetracycline (E-TC), clarithromycin (CLR), ciprofloxacin (CIP), ofloxacin (OFX), epioxytetracycline (E-OTC), tetracyclines (TC), oxytetracycline (OTC), and norfloxacin (NOR) were observed. In summary, it is important to ensure the stable operation of small town WWTPs to reduce the ecological risk of antibiotics.

Novel MRI-compatible tactile stimulator for cortical mapping of foot sole pressure stimuli with fMRI.

Foot sole somatosensory feedback is critical to motor control and declines with aging and disease. To enable study of cortical networks underlying foot sole somatosensation, we developed a pneumatic tactile stimulator capable of producing one degree-of-freedom (DOF) oscillations with preset waveform, frequency (≤10 Hz), force magnitude (5-500 N), duty cycle (20-100%), and contacted surface area over which pressures are applied to the foot sole. Image tests (anatomical/functional/field map) of a phantom demonstrated that the device is compatible with 3 T MRI. Gradient-recalled echo-planar images of seven healthy young adults using a typical block-designed 1 Hz sinusoidal stimulation protocol revealed significant activation contralaterally within the primary somatosensory cortex and paracentral gyrus, and bilaterally within the secondary somatosensory cortex. The stimulation system may therefore serve as a research tool to study functional brain networks involved in the perception and modulation of foot sole somatosensation and its relationship to motor control.