Fluorescent ensemble based on PBI/SDS assemblies exhibiting cross-reactive responses and discriminative behaviors to multiple aminoglycoside antibiotics in both aqueous solution and serum samples.
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•Three PBI-based fluorescent probes with different side chains were synthesized.•The structure and polarity of side chains influence aggregation behaviors of PBI derivatives in water.•SDS assemblies effectively modulate fluorescence emission of PBI with polar side chains.•Binary sensor system shows turn-on fluorescence responses to aminoglycoside antibiotics.•Ternary sensor system can discriminate multiple aminoglycoside antibiotics.
Fluorescent aggregates and ensembles have been widely applied in fabrication of fluorescent sensors due to their capacity of encapsulating fluorophores and modulating their photophysical properties. In the present work, fluorescent ensembles based on anionic surfactant SDS assemblies and perylene derivatives (PBIs) were particularly constructed. Three newly synthesized neutral PBI derivatives with different structures, PO, PC1 and PC2, were used for the purpose to evaluate probe structure influence on constructing fluorescent ensembles. The one with hydrophilic side chains, PO, experienced distinct photophysical modulation effect by SDS assemblies. The ensemble based on PO@SDS assemblies displayed effective fluorescence variation to antibiotic aminoglycosides (AGs). To improve cross-reactivity and discrimination capability of ensembles, a second probe, coumarin, was introduced into PO@SDS assemblies. The resultant ternary sensor, CM-PO@SDS, exhibited good qualitative and quantitative detection capabilities, and achieved differentiation of eight AGs and mixed AG samples both in aqueous solution and actual biological fluid, like human serum. Sensing mechanism studies revealed that hydrogen bonding, electrostatic and hydrophobic interactions are involved in the sensing process. This surfactant-based fluorescent ensemble provides a simple and feasible method for assessing AGs levels. Meanwhile, this work may provide some insights to design reasonable probes for constructing effective single-system based discriminative fluorescent amphiphilic sensors.
A novel dummy molecularly imprinted polymers (DMIPs) for aminoglycoside antibiotics (AAs) was prepared for the first time by precipitation polymerization using raffinose as template molecule, ...methacrylic acid as functional monomer and trimethylolpropane triacrylate as cross-linker. The obtained DMIPs were characterized in detail, and their adsorbing and recognition performance were evaluated. The results showed that the DMIPs exhibited specific recognition towards six AAs with large adsorption capacity. The dummy molecularly imprinted solid phase extraction (DMISPE) conditions including elution/washing solutions and sample loading volumes were optimized. Under optimum conditions, a convenient and efficient method for the determination of AAs in environmental water samples based on DMISPE coupling with hydrophilic interaction-high performance liquid chromatography-tandem mass spectrometry was established. The developed method showed good linearity with correlation coefficients higher than 0.9921 for all the analytes and good recoveries (70.8–108.3%) with relative standard deviations from 2.6 to 11.4% spiked at three different concentration levels in water samples. The limit of detection (S/N = 3) ranged from 0.006 to 0.6 ng/mL. The results demonstrated good potential of DMIPs for sample pretreatment of trace AAs in environmental water samples.
Schematic illustration of the synthetic process of dummy molecularly imprinted polymers for determination of aminoglycoside antibiotics in environmental water samples. Display omitted
•Dummy molecularly imprinted polymers (DMIPs) for aminoglycoside antibiotics was prepared.•Raffinose was used as the dummy template for synthesizing polymers.•DMISPE coupled with HILIC-LC-MS/MS method was developed for analysis of aminoglycoside antibiotics.•The developed method was simple and sensitive.
The use of aminoglycoside antibiotics is prevalent in medicine and agriculture. Their overuse increases their mobility in the environment, resulting in a need for reliable methods for their ...determination in a variety of matrices. However, the properties of aminoglycosides, in particular their high polarity, make the development of such methods a non-trivial task, inciting researchers to tackle this complex issue from different angles. The necessity to determine aminoglycosides in complex matrices and at low concentration levels requires the development of relatively elaborate sample preparation methods and the use of selective and sensitive detection techniques. Various modes of liquid chromatography coupled with tandem mass spectrometry are usually the analytical methods of choice. However, the recent developments in techniques such as bioassays, quantum dot-based colourimetric applications and various aptasensors point towards the development of more easily accessible and user-friendly point-of-need tests for screening applications in food control and environmental monitoring. This review summarizes the state-of-the-art in sample preparation protocols and the determination of aminoglycosides using various techniques and outlines the future trends with an emphasis placed on the novel and emerging solutions in this area.
•Reliable analytical methods are needed for determining aminoglycoside antibiotics.•We review the state-of-the-art in sample preparation and detection techniques.•Trends in the development of both LC-based and emerging methods are discussed.
Aminoglycoside antibiotics (AAs) have been extensively applied in medical field and animal husbandry owing to desirable broad-spectrum antibacterial activity. Excessive AAs residues in the ...environment can be accumulated in human body through food chain and cause detrimental effect on human health. The establishment of highly specific, simple and sensitive detection methods for monitoring AAs residues is highly in demand. Aptasensor using aptamer as the biological recognition element is the efficient and promising sensing method for detection of AAs. In this review, we have made a summary of specific aptamers sequences against AAs. Subsequently, we provide a systematical and comprehensive overview of modern techniques in aptasensors for detection of AAs according to optical aptasensors as well as electrochemical aptasensors and further summarize their advantages and disadvantages to compare their applications. In addition, we present an overview of practical applications of aptasensors in sample detection of AAs. Moreover, the current challenges and future trends in this field are also included to reveal a promising perspective for developing novel aptasensors for AAs.
Overview of aptamer-based sensors for detection of aminoglycoside antibiotics. Display omitted
•Aptamers sequences of aminoglycoside antibiotics are summarized.•Recent advances in detection of aminoglycoside antibiotics based on optical aptasensors and electrochemical aptasensors are reviewed.•The application of aptasensors for detection of aminoglycoside antibiotics in real samples is summarized.•Current challenges and future perspectives of aminoglycoside antibiotics aptasensors are discussed.
It has become increasingly clear that low levels of antibiotics present in many environments can select for resistant bacteria, yet the evolutionary pathways for resistance development during ...exposure to low amounts of antibiotics remain poorly defined. Here we show that Salmonella enterica exposed to sub-MIC levels of streptomycin evolved high-level resistance via novel mechanisms that are different from those observed during lethal selections. During lethal selection only rpsL mutations are found, whereas at sub-MIC selection resistance is generated by several small-effect resistance mutations that combined confer high-level resistance via three different mechanisms: (i) alteration of the ribosomal RNA target (gidB mutations), (ii) reduction in aminoglycoside uptake (cyoB, nuoG, and trkH mutations), and (iii) induction of the aminoglycoside-modifying enzyme AadA (znuA mutations). These results demonstrate how the strength of the selective pressure influences evolutionary trajectories and that even weak selective pressures can cause evolution of high-level resistance.
Herein, a dual-emission Eu metal-organic framework (Eu-MOF) is prepared and used as the ratiometric fluorescence probe for ultrasensitive detection of aminoglycoside antibiotics (AGs). Due to the ...strong hydrogen bond interactions between AGs and Eu-MOF, the blue emission is enhanced while the red emission has little fluctuation in Eu-MOF with the addition of AGs, thus a good linear relationship with the logarithm of AGs concentrations from 0.001 to 100 μg/mL can be established for quantitative analysis. Good sensitivity with the detection limit of 0.33 ng/mL for apramycin, 0.32 ng/mL for amikacin and 0.30 ng/mL for kanamycin is achieved. The proposed assay demonstrates good selectivity and applicability for determination of AGs in real milk and honey samples. The Eu-MOF materials are further fabricated as fluorescent test papers for facile visual detection. The as-established ratio fluorescence platform offers a portable and economical way for rapid monitoring AGs residues in complex food samples.
Synopsis: The Eu-MOF is composed of two ligands of 2-aminoterephthalic acid (BDC-NH2) and 1,10-phenanthroline (phen) that coordinated to Eu3+, which emits blue fluorescence at 434 nm and red fluorescence at 613 nm under 365 nm excitation. In the presence of AGs, the blue emission is enhanced while the red emission has little fluctuation in Eu-MOF, thus detection of AGs is achieved by using Eu-MOF as ratiometric fluorescence probe, and the visual fluorescence variation from red to purple to blue can be readout by naked eyes using Eu-MOF loaded test paper. Display omitted
•Eu-MOF ratiometric fluorescence probe is designed for ultrasenstive AGs detection.•Detection mechanism is based on enhancing the ICT effect of Eu-MOF by adding AGs.•Eu-MOF test paper is further fabricated as portable sensor for visual analyzing AGs.•It offers an economical way for rapid detection of AGs residues in real food samples.
Class 1 integrase intI1 has been considered as a good proxy for anthropogenic pollution because of being linked to genes conferring resistance to antibiotics. The gene cassettes of class 1 integrons ...could carry diverse antibiotic resistance genes (ARGs) and conduct horizontal gene transfer among microorganisms. The present study applied high-throughput sequencing technique combined with an intI1 database and genome assembly to quantify the abundance of intI1 in 64 environmental samples from 8 ecosystems, and to investigate the diverse arrangements of ARG-carrying gene cassettes (ACGCs) carried by class 1 integrons. The abundance of detected intI1 ranged from 3.83 × 10–4 to 4.26 × 10° intI1/cell. High correlation (Pearson’s r = 0.852) between intI1 and ARG abundance indicated that intI1 could be considered as an important indicator of ARGs in environments. Aminoglycoside resistance genes were most frequently observed on gene cassettes, carried by 57% assembled ACGCs, followed by trimethoprim and beta-lactam resistance genes. This study established the pipeline for broad monitoring of intI1 in various environmental samples and scanning the ARGs carried by integrons. These findings supplemented our knowledge on the distribution of class 1 integrons and ARGs carried on mobile genetic elements, benefiting future studies on horizontal gene transfer of ARGs.
Pharmaceutical drug therapy is often hindered by issues caused by poor drug selectivity, including unwanted side effects and drug resistance. Spatial and temporal control over drug activation in ...response to stimuli is a promising strategy to attenuate and circumvent these problems. Here we use ultrasound to activate drugs from inactive macromolecules or nano-assemblies through the controlled scission of mechanochemically labile covalent bonds and weak non-covalent bonds. We show that a polymer with a disulfide motif at the centre of the main chain releases an alkaloid-based anticancer drug from its β-carbonate linker by a force-induced intramolecular 5-exo-trig cyclization. Second, aminoglycoside antibiotics complexed by a multi-aptamer RNA structure are activated by the mechanochemical opening and scission of the nucleic acid backbone. Lastly, nanoparticle-polymer and nanoparticle-nanoparticle assemblies held together by hydrogen bonds between the peptide antibiotic vancomycin and its complementary peptide target are activated by force-induced scission of hydrogen bonds. This work demonstrates the potential of ultrasound to activate mechanoresponsive prodrug systems.
Emergence of epidemic clones and antibiotic resistance development compromises the management of Pseudomonas aeruginosa cystic fibrosis (CF) chronic respiratory infections. Whole genome sequencing ...(WGS) was used to decipher the phylogeny, interpatient dissemination, WGS mutator genotypes (mutome) and resistome of a widespread clone (CC274), in isolates from two highly-distant countries, Australia and Spain, covering an 18-year period. The coexistence of two divergent CC274 clonal lineages was revealed, but without evident geographical barrier; phylogenetic reconstructions and mutational resistome demonstrated the interpatient transmission of mutators. The extraordinary capacity of P. aeruginosa to develop resistance was evidenced by the emergence of mutations in >100 genes related to antibiotic resistance during the evolution of CC274, catalyzed by mutator phenotypes. While the presence of classical mutational resistance mechanisms was confirmed and correlated with resistance phenotypes, results also showed a major role of unexpected mutations. Among them, PBP3 mutations, shaping up β-lactam resistance, were noteworthy. A high selective pressure for mexZ mutations was evidenced, but we showed for the first time that high-level aminoglycoside resistance in CF is likely driven by mutations in fusA1/fusA2, coding for elongation factor G. Altogether, our results provide valuable information for understanding the evolution of the mutational resistome of CF P. aeruginosa.
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