Groundwater antibiotics contamination in an alluvial-pluvial fan, North China Plain: Occurrence, sources, and risk assessment

Priority list of pharmaceutical active compounds in aquatic environments of Mexico considering their occurrence, environmental and human health risks

Pharmaceutical active compounds (PhACs) are detected pollutants in aquatic environments worldwide at concentrations ranging from ng L-1 to µg L-1. Currently, PhAC monitoring is poorly realized in Mexico. This study proposes a priority list of PhACs in Mexican aquatic environments, considering their occurrence and environmental and human health risks. Ecological risks were assessed as Risk Quotients (RQ) values using the PhAC concentrations detected in surface water, obtaining high risks (RQ > 1) against aquatic organisms, especially of naproxen, ibuprofen, diclofenac, acetaminophen, 17β-estradiol, carbamazepine, ketoprofen, caffeine. In contrast, potential human health risks (RQH) were assessed on the Mexican population using the concentrations quantified in groundwater, demonstrating potential risks (RQH > 0.2) on the population, particularly of DCF and CBZ. Thus, a priority list of PhACs can be used as a reference for environmental monitoring in Mexican water supplies as well as PhACs monitoring in countries of the Caribbean region and Central America.

Spatiotemporal distribution and potential risks of antibiotics in coastal water of Beibu Gulf, South China Sea: Livestock and poultry emissions play essential effect

Antibiotics have been the subject of much attention in recent years due to their widespread use and the potential ecological risks and resistance risks. In this study, we conducted an extensive survey of 19 antibiotics in a wide range of waters of the Beibu Gulf during summer and winter (154 samples). The total concentrations of the 19 antibiotics (Σ19ABs, ng/L) were significantly higher in winter (n.d.-364) than in summer (n.d.-70.1) and were mainly concentrated in areas of seagoing rivers (1.50-364). The primary route for antibiotics entering Beibu Gulf was through riverine input. Precisely, florfenicol (FF) (n.d.-278 ng/L) discharged from livestock and poultry farms upstream of Nanliu River, predominantly in swine farming, constitutes the main pollutant in Beibu Gulf throughout the year. The Nanliu River (988 kg/a) accounts for 85% of the gulf's total annual antibiotic emission flux. Source analysis identified livestock and poultry farming, particularly swine farming, as the primary pollution source, contributing 58% in summer. Risk assessment reveals that algae (0.51 ± 0.56) exhibited relatively high sensitivity to antibiotics, presenting a medium-high risk at specific sites in Nanliu River during winter. Additionally, FF discharged from swine farming demonstrates a certain level of antibiotic resistance risk. Therefore, reinforcing control measures for antibiotic discharges from livestock and poultry farming, especially upstream of Nanliu River, can effectively mitigate antibiotic-related risks in the water bodies of Beibu Gulf.

Research on Bacterial Diversity and Antibiotic Resistance in the Dairy Farm Environment in a Part of Shandong Province

Antimicrobials are extensively utilized in dairy farms to prevent and control diseases in cattle. However, their use contributes to the emergence of antimicrobial-resistant bacteria (ARB) and antimicrobial-resistant genes (ARG), and these can be transmitted to the environment. Regular monitoring of antimicrobial resistance (AMR) is crucial for implementing effective mitigation strategies. This research aimed to assess the environmental microbial species present on dairy farms in Shandong Province and characterize the antimicrobial resistance profiles of the isolates. Five dairy farms located in Shandong Province were selected, representing the prevalent large-scale farming patterns in the area. Sampling took place from April to June 2022, with a total of 223 isolates collected from various environmental locations within each farm (bedding, sports field, and milking parlor). Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) was employed to identify the species of the clinical isolates. The main pathogens isolated were Aerococcus viridans (5.38%, n = 12), Corynebacterium xerosis (4.93%, n = 11), and Acinetobacter lwoffii (4.03%, n = 9). Among the bacterial isolates, resistance to lincomycin was highest at 91%, and 88% were resistant to sulfadiazine. Antimicrobial resistance genes were detected in only a small proportion of the isolates, the most common of which was sul1. These findings highlight the necessity for careful evaluation of antimicrobial usage in maintaining their effectiveness in human medicine. Understanding the microbial species present and their antimicrobial resistance profiles aids in focusing efforts toward sustainable antimicrobial use and safeguarding human health.

Response of microbial community to different media in start-up period of Annan constructed wetland in Beijing of China

Microbial community, as the decomposers of constructed wetland (CW), plays crucial role in biodegradation and biotransformation of pollutants, nutrient cycling and the maintenance of ecosystem balance. In this study, 9 water samples, 6 sediment samples, and 8 plant samples were collected in Annan CW, which has the functions of water treatment and wetland culture park. The characteristics of microbial community structure in different media were illustrated by using of high-throughput sequencing-based metagenomics approach and statistical analysis. Meanwhile, this study identified and classified human pathogens in CW to avoid potential risks to human health. The results showed that dominant bacteria phyla in CW include Proteobacteria, Bacteroides, Actinobacteria, Firmicutes and Verrucomicrobia. The distribution of microorganisms in three media is different, but not significant. And the pH and DO profoundly affected microbe abundance, followed by water temperature. The microbial diversity in sediments is the highest, which is similar with the detection of human pathogens in sediments. Moreover, compared with Calamus, Lythrum salicaria and Reed, Scirpus tabernaemontani has fewer pathogenic microorganisms. The distribution of microorganisms in the CW is complex, and a variety of human pathogens are detected, which is more prone to create potential risks to human health and should receive additional attention.