We have carefully built a new chloramphenicol (CAP) electrochemical sensor, which takes the zinc tungstate @ cobalt magnetic nanoporous carbon @ molecularly imprinted polymer (ZnWO4@Co-MNPC@MIP) as the core. First, we successfully prepared Co-MNPC nanomaterials using an efficient one-step hydrothermal method and a direct carbonization method. Next, we recombined ZnWO4 with Co-MNPC and synthesized the completely new ZnWO4@Co-MNPC complex by using the hydrothermal method. To further improve its performance, we combined ZnWO4@Co-MNPC with a molecular imprinted polymer and coated a molecular imprinted (MIP) shell on the surface of ZnWO4@Co-MNPC by precipitation polymerization. This shell not only gives the sensor a new performance but also gives it a stronger peak current, resulting in a more accurate detection of CAP. Under optimal conditions, the ZnWO4@Co-MNPC@MIP (MMIP) electrode has a stronger CAP detection peak current than the one-component electrode, with a fairly wide linear range: 0.007-200 μM and 200-1400 μM. Even more surprisingly, the detection limit is as low as 0.0027 μM, which allows the sensor to maintain excellent selectivity and stability in the face of various interferences, making it an excellent electrochemically modified electrode. Compared to magnetic non-molecular imprint sensors (MNIPs), MMIP sensors have higher detection efficiency. After practical application, we found that the ZnWO4@Co-MNPC@MIP modified electrode was satisfactory in milk samples.

UNASSIGNED: Topical chloramphenicol is one of the most ubiquitous antibiotics used in ophthalmology and oculoplastic surgery globally. It shows broad-spectrum activity against a variety of different pathogenic organisms, is well tolerated on the ocular surface and displays excellent topical pharmacokinetics. Chloramphenicol has been available for purchase over the counter in the United Kingdom since 2005. Despite this, the largest health economy in the world, The United States has had a de-facto moratorium on its use for the past 30 years. In this review, we aim to evaluate topical chloramphenicol in ophthalmology and oculoplastic surgery and to determine whether its reputation within the US is warranted and justified.
UNASSIGNED: We conducted a comprehensive literature review to evaluate the different facets of chloramphenicol, providing a detailed understanding of the drug, its historical context, the benefits and perceived risks, including safety concerns, and clinical perspectives of its use in clinical practice.
UNASSIGNED: The mechanism of chloramphenicol, the context around which the drug\'s use in the US declined, and the drug\'s evidence base and safety data, including published case reports of serious adverse events, were analysed. The perceived benefits of the drug, particularly in light of antimicrobial resistance and its economic impact, were reviewed. Finally, perspectives on its use in clinical practice in ophthalmology and associated allied specialities were presented.
UNASSIGNED: Chloramphenicol and its topical application have been misunderstood for many decades, particularly in the United States. Its demise across the Atlantic was due to an overzealous response to a dubious association with a weak evidence base. Numerous authors have since validated the safety profile of the and its safety has been borne out. The benefits of chloramphenicol, an effective broad-spectrum agent with a positive cost differential in the era of anti-microbial resistance and fiscal tightening, cannot be understated. Its likely effectiveness as a therapeutic topical agent in ophthalmic surgery makes it a valuable tool in the ophthalmic anti-microbial armoury. We would encourage the reinstatement of this valuable yet misunderstood drug as a first-line agent for simple ophthalmic infections.

Chloramphenicol (CHL) is an antibiotic targeting the peptidyl transferase center in bacterial ribosomes. We synthesized a new analog, CAM-BER, by substituting the dichloroacetyl moiety of CHL with a positively charged aromatic berberine group. CAM-BER suppresses bacterial cell growth, inhibits protein synthesis in vitro, and binds tightly to the 70S ribosome. Crystal structure analysis reveals that the bulky berberine group folds into the P site of the peptidyl transferase center (PTC), where it competes with the formyl-methionine residue of the initiator tRNA. Our toe-printing data confirm that CAM-BER acts as a translation initiation inhibitor in stark contrast to CHL, a translation elongation inhibitor. Moreover, CAM-BER induces a distinct rearrangement of conformationally restrained nucleotide A2059, suggesting that the 23S rRNA plasticity is significantly higher than previously thought. CAM-BER shows potential in avoiding CHL resistance and presents opportunities for developing novel berberine derivatives of CHL through medicinal chemistry exploration.

Rapid, efficient, versatile, easy-to-use, and non-expensive analytical approaches are globally demanded for food analysis. Many ambient ionization approaches based on electrospray ionization (ESI) have been developed recently for the rapid molecular characterization of food products. However, those approaches mainly suffer from insufficient signal duration for comprehensive chemical characterization by tandem MS analysis. Here, a commercially available disposable gel loading tip is used as a low-cost emitter for the direct ionization of untreated food samples. The most important advantages of our approach include high stability, and durability of the signal (> 10 min), low cost (ca. 0.1 USD per run), low sample and solvent consumption, prevention of tip clogging and discharge, operational simplicity, and potential for automation. Quantitative analysis of sulfapyridine, HMF (hydroxymethylfurfural), and chloramphenicol in real sample shows the limit-of-detection 0.1 μg mL-1, 0.005 μg mL-1, 0.01 μg mL-1; the linearity range 0.1-5 μg mL-1, 0.005-0.25 μg mL-1, 0.01-1 μg mL-1; and the linear fits R2 ≥ 0.980, 0.991, 0.986. Moreover, we show that tip-ESI can also afford sequential molecular ionization of untreated viscous samples, which is difficult to achieve by conventional ESI. We conclude that tip-ESI-MS is a versatile analytical approach for the rapid chemical analysis of untreated food samples.

Three functional magnetic nanocatalytic probe, which integrates recognition, catalytic amplification, and separation enrichment, is a new approach to construct a simple, fast, highly selective, and sensitive analytical method. In this article, a new magnetic nanosurface molecularly imprinted polymer nanoprobe (Fe3O4@MIP) with trifunctionality was rapidly prepared using a microwave-assisted method with magnetic Fe3O4 nanoparticles as a substrate, chloramphenicol (CAP) as a template molecule, and methacrylic acid as a functional monomer. The characterized nanoprobe was found that could specifically recognize CAP, strongly catalyze the new indicator nanoreaction of fructose (DF)-HAuCl4. The gold nanoparticles (AuNPs) exhibit strong resonance Rayleigh scattering (RRS) and surface enhanced Raman scattering (SERS) effects. Upon addition of CAP, the SERS/RRS signals were linearly weakened. Accordingly, a new SERS/RRS analysis platform for highly sensitive and selective determination of CAP was constructed. The SERS linear range was 0.0125-0.1 nmol/L, with detection limit (DL) of 0.004 nmol/L CAP. Furthermore, it could be combined with magnet-enriched separation to further improve the sensitivity, with a DL of 0.04 pmol/L CAP. The SERS method has been used for the determination of CAP in real samples, with relative standard deviations of 2.37-9.89 % and the recovery of 95.24-107.1 %.

Electrospun (ES) fibrous nanomaterials have been widely investigated as novel biomaterials. These biomaterials have to be safe and biocompatible; hence, they need to be tested for cytotoxicity before being administered to patients. The aim of this study was to develop a suitable and biorelevant in vitro cytotoxicity assay for ES biomaterials (e.g. wound dressings). We compared different in vitro cytotoxicity assays, and our model wound dressing was made from polycaprolactone and polyethylene oxide and contained chloramphenicol as the active pharmaceutical ingredient. Baby Hamster Kidney cells (BHK-21), human primary fibroblasts and MTS assays together with real-time cell analysis were selected. The extract exposure and direct contact safety evaluation setups were tested together with microscopic techniques. We found that while extract exposure assays are suitable for the initial testing, the biocompatibility of the biomaterial is revealed in in vitro direct contact assays where cell interactions with the ES wound dressing are evaluated. We observed significant differences in the experimental outcome, caused by the experimental set up modification such as cell line choice, cell medium and controls used, conducting the phosphate buffer washing step or not. A more detailed technical protocol for the in vitro cytotoxicity assessment of ES wound dressings was developed.

Despite the beneficial effects of antibiotics such as chloramphenicol (CAP), they exert some destructive impacts on human health. We designed an electrochemical sensor based on reduced graphene oxide (rGO)/Au/Co2CuS4 nanohybrid for determination of CAP in food and biological samples. The Co2CuS4 was synthesized from binuclear metal-organic framework (CoCu-BDC) through a two-step process. Nanohybrid was characterized by X-ray photoelectron spectroscopy and transmission electron microscopy. The rGO/Au/Co2CuS4 provides more active sites and good electrical conductivity to reduce charge transfer resistance and improve the electrocatalytic activity for determination of CAP. The prepared sensor has a wide linear range from 7 to 141 nM with a limit of detection of 2.5 nM and a limit of quantification of 21.92 nM. It also provided high selectivity and repeatability with a relative standard deviation of 2.6%. Stability studies showed that the electrode has acceptable performance with efficiency of 95% after 33 days.

The aim of this study was to evaluate the proportion of resistance to a temocillin, tigecycline, ciprofloxacin, and chloramphenicol phenotype called t2c2 that resulted from mutations within the ramAR locus among extended-spectrum β-lactamases-Enterobacterales (ESBL-E) isolated in three intensive care units for 3 years in a French university hospital. Two parallel approaches were performed on all 443 ESBL-E included: (i) the minimal inhibitory concentrations of temocillin, tigecycline, ciprofloxacin, and chloramphenicol were determined and (ii) the genomes obtained from the Illumina sequencing platform were analyzed to determine multilocus sequence types, resistomes, and diversity of several tetR-associated genes including ramAR operon. Among the 443 ESBL-E strains included, isolates of Escherichia coli (n = 194), Klebsiella pneumoniae (n = 122), and Enterobacter cloacae complex (Ecc) (n = 127) were found. Thirty-one ESBL-E strains (7%), 16 K. pneumoniae (13.1%), and 15 Ecc (11.8%) presented the t2c2 phenotype in addition to their ESBL profile, whereas no E. coli presented these resistances. The t2c2 phenotype was invariably reversible by the addition of Phe-Arg-β-naphthylamide, indicating a role of resistance-nodulation-division pumps in these observations. Mutations associated with the t2c2 phenotype were restricted to RamR, the ramAR intergenic region (IR), and AcrR. Mutations in RamR consisted of C- or N-terminal deletions and amino acid substitutions inside its DNA-binding domain or within key sites of protein-substrate interactions. The ramAR IR showed nucleotide substitutions involved in the RamR DNA-binding domain. This diversity of sequences suggested that RamR and the ramAR IR represent major genetic events for bacterial antimicrobial resistance.IMPORTANCEMorbimortality caused by infectious diseases is very high among patients hospitalized in intensive care units (ICUs). A part of these outcomes can be explained by antibiotic resistance, which delays the appropriate therapy. The transferable antibiotic resistance gene is a well-known mechanism to explain the high rate of multidrug resistance (MDR) bacteria in ICUs. This study describes the prevalence of chromosomal mutations, which led to additional antibiotic resistance among MDR bacteria. More than 12% of Klebsiella pneumoniae and Enterobacter cloacae complex strains presented mutations within the ramAR locus associated with a dysregulation of an efflux pump called AcrAB-TolC and a porin: OmpF. These dysregulations led to an increase in antibiotic output notably tigecycline, ciprofloxacin, and chloramphenicol associated with a decrease of input for beta-lactam, especially temocillin. Mutations within transcriptional regulators such as ramAR locus played a major role in antibiotic resistance dissemination and need to be further explored.

Limited literature exists on chloramphenicol\'s clinical use. In this retrospective, single-center case-series, we examined 183 chloramphenicol-treated and 81 piperacillin-tazobactam-treated medical patients. Chloramphenicol recipients were older, more debilitated, cognitively impaired, and penicillin allergic, while increased need for inotropics, higher leukocyte count, and higher creatinine levels were notable in the piperacillin-tazobactam group. Pneumonia was the most common indication, with no mortality difference between groups. While acknowledging its antimicrobial activity and potential benefit in specific conditions such as pneumonia, further clinical studies are needed to assess the role of chloramphenicol in the setting where other alternatives are available.

Chloramphenicol (CAP) poses a threat to human health due to its toxicity and bioaccumulation, and it is very important to measure it accurately and sensitively. This work explored a host-guest recognition strategy to mediate dual aggregation-induced electrochemiluminescence (AIECL) of 1,1,2,2-tetrakis(4-(pyridin-4-yl) phenyl)-ethene (TPPE) for ratio detection of CAP, in which, cucurbit[8]uril (CB[8]) served as host to assemble guest TPPE. The resulting supramolecular complex CB[8]-TPPE exhibited excellent dual-AIECL-emission with signal strength approximately four times that of TPPE aggregates and black hole quencher-1 (BHQ1) could efficiently quench dual-AIECL signal. CB[8]-TPPE coupled dual-function quencher BHQ1 and high-efficiency DNA reactor to achieve ultra-sensitive detection of CAP, exhibiting a linearity range of 10 fmol·L-1-100 nmol·L-1 and limit of detection of 1.81 fmol·L-1. CB[8]-TPPE provides a novel way to improve the dual-emission of TPE derivatives and sets up a promising platform for CAP detection, demonstrating a good practical application potential.