Pharma-molecule Transport across Bacterial Membranes: Detection and Quantification Approaches by Electrochemistry and Bioanalytical Methods

Interaction of sulfate-reducing bacteria and methanogenic archaea in urban sewers, leads to increased risk of proliferation of antibiotic resistance genes

Sewers are considered a potential reservoir of antibiotic resistance. However, the generation of antibiotic resistance genes (ARGs) in microbial communities in pipeline biofilms under antibiotic stress remains unexplored. In this study, the biodegradation efficiency of tetracycline (TCY) and sulfamethoxazole (SMX) was evaluated in a pilot reactor of the sewers. The results showed that under TCY and SMX stress, the degradation efficiency of sewage water was inhibited. The most abundant ARGs detected in the biofilm samples were TCY-related genes (e.g., tetW/N/W, tetC, and tetM), accounting for 34.1%. The microbial community composition varied, and the correlation analysis showed that antibiotic stress had a certain impact on the biological metabolic activity and function of the urban sewers. The community structure and diversity of biofilms enabled the evaluation of the bioconversion of antibiotics. Notably, Anaerocella and Paludibacter directly influenced the methanogenesis and sulfate reduction processes, playing a key role in the interaction between sulfate-reducing bacteria and methanogenic archaea. These microorganisms facilitated the proliferation of ARGs (tet and sul) in the biofilms through horizontal gene transfer. This study provides insight into the front-end control of ARGs, further improving sewage treatment plant processes and reducing the environmental and health risks caused by antibiotic abuse.

Ultrasensitive and facile detection of multiple trace antibiotics with magnetic nanoparticles and core-shell nanostar SERS nanotags

Ultrasensitive, multiplex, rapid, and accurate quantitative determination of trace antibiotics remains a challenging issue, which is of importance to public health and safety. Herein, we presented a multiplex strategy based on magnetic nanoparticles and surface-enhanced Raman scattering (SERS) nanotags for simultaneous detection of chloramphenicol (CAP) and tetracycline (TTC). In practice, SERS nanotags based on Raman reporter probes (RRPs) encoded gold-silver core-shell nanostars were used as detection labels for identifying different types of antibiotics, and the magnetic nanoparticles could be separated simply by magnetic force, which significantly improves the detection efficiency, reduces the analysis cost, and simplifies the operation. Our results demonstrate that the as-proposed assay possesses the capacities of high sensitivity and multiplexing with the limits of detection (LODs) for CAP and TTC of 159.49 and 294.12 fg mL^-1, respectively, as well as good stability and reproducibility, and high selectivity and reliability. We believe that this strategy holds a great promising perspective for the detection of trace amounts of antibiotics in microsystems, which is crucial to our life. Additionally, the assay can also be used to detect other illegal additives by altering the appropriate antibodies or aptamers.

Pico-molar electrochemical detection of ciprofloxacin at composite electrodes

Rapid determination of ciprofloxacin at OCNTs-PDA-Ag sensors enables environmental monitoring and future bioelectrochemical studies.