Different Concentrations Of Chloramphenicol Research Articles

A highly sensitive electrochemical sensor for the detection of chloramphenicol based on Ni/Co bimetallic metal-organic frameworks/reduced graphene oxide composites

A highly and simply sensitive electrochemical sensor has been developed for the detection of trace chloramphenicol (CAP) in water based on Ni/Co bimetallic metal–organic frameworks-reduced graphene oxide composites [rGO/NiCo-BTC MOFs (BTC = 1,3,5-benzenetricarboxylicacid)] modified glassy carbon electrode (GCE/rGO/NiCo-BTC MOFs). The bare glassy carbon electrode was initially coated with graphene oxide (GO). Subsequently, the GO was electrochemically reduced to obtain reduced graphene oxide (rGO). NiCo-BTC MOFs was grown on the surface of rGO modified electrode by in-situ electrochemical synthesis method to construct GCE/rGO/NiCo-BTC MOFs. The as-made composites films have been characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Further, different electrochemical techniques were utilized for investigating the electrochemical reduction behaviors of CAP at GCE/rGO/NiCo-BTC MOFs. This composites film modified electrode combines the large surface area and excellent electrical properties of rGO with the good catalytic activity of NiCo-BTC MOFs, resulting in a significant enhancement of the electrochemical signal during the electroreduction of CAP. Under the optimized experimental conditions, the sensor exhibits excellent sensing performance for CAP, with a wider linear dynamic range (0.1 − 100 μM), a lower limit of detection (0.235 μM) (S/N = 3) and a ultra-high sensitivity (33.12 μA·μM−1·cm−2). The tap water spiked with different concentrations of CAP were considered. The recoveries range from 97.79 % to 100.07 %, with relative standard deviations ranging from 3.45 % to 5.40 %. The method has been successfully applied for the determination of CAP in real samples, yielding satisfactory results. With further research and development, electrochemical in-situ synthesis of MOFs composites have the potential to revolutionize the design and performance of electrochemical sensors, holding great promise in the field of electrochemical sensing.

Nanoparticles coated by chloramphenicol in hydrogels as a useful tool to increase the antibiotic release and antibacterial activity in dermal drug delivery

BackgroundNanocarriers for antibacterial drugs became hopeful tools against the increasing resistance of bacteria to antibiotics. This work focuses on a comprehensive study of the applicability and therapeutic suitability of dermal carbopol-based hydrogels containing chloramphenicol carried by various nanoparticles (AuNPs and SiNPs).MethodsThe different forms of carbopol-based drugs for dermal use were obtained. Five different concentrations of chloramphenicol and two types of nanoparticles (silica and gold) in carbopol-based ointments were tested. The influence of different carbopol formulations with nanocarriers on the rheological properties as well as the release profile of active substances and bacteriostatic activity on five reference strains were determined.ResultsThe properties of the obtained hydrogels were compared to a commercial formulation, and finally it was possible to obtain a formulation that allowed improved antimicrobial activity over a commercially available detreomycin ointment while reducing the concentration of the antibiotic.ConclusionThe work indicates that it is possible to reduce the concentration of chloramphenicol by four times while maintaining its bacteriostatic activity, which can improve the patient’s safety profile while increasing the effectiveness of the therapy.Graphical abstract

In Vitro Photo-Catalytic Degradation of Chloramphenicol Using Pharmaceutical Wastewater

Abstract: In this work, the performance of composite membranes for the treatment of Chloramphenicol (CAP) pollutants was investigated from pharmaceutical industrial wastewater. The composite membrane was under operated with different concentrations of CAP with Titanium dioxide (TiO2) in 10mg/L, 20mg/L and 30 mg/L. The composite membranes were cross-linked with glutaraldehyde for the elimination of H2SO4. Characterizations of synthesized composite membranes were carried out to analyze functionality, morphology, and hydrophilic behaviours. In continuous operation, the different time intervals of TiO2 were removed in centrifuging. The performance of the composite membrane is the removal of pollutant CAP by UV analysis, and kinetics model at different concentrations. The degree of swelling and contact angle were measured in different concentrations of CAP at TiO2. Liquid Chromatography (LC) is used to CAP with Titanium dioxide mixtures. Mass Spectrometry (MS) can be used for structural identity with high specificity. The MS is also used to analyze CAP from pharmaceutical industrial wastewater. The membranes were subjected to filtration of pharmaceutical wastewater which gave a maximum rejection of 95% of Chloramphenicol.

In Vitro Photo-Catalytic Degradation of Chloramphenicol Using Pharmaceutical Wastewater

Abstract: In this work, the performance of composite membranes for the treatment of Chloramphenicol (CAP) pollutants was investigated from pharmaceutical industrial wastewater. The composite membrane was under operated with different concentrations of CAP with Titanium dioxide (TiO2) in 10mg/L, 20mg/L and 30 mg/L. The composite membranes were cross-linked with glutaraldehyde for the elimination of H2SO4. Characterizations of synthesized composite membranes were carried out to analyze functionality, morphology, and hydrophilic behaviours. In continuous operation, the different time intervals of TiO2 were removed in centrifuging. The performance of the composite membrane is the removal of pollutant CAP by UV analysis, and kinetics model at different concentrations. The degree of swelling and contact angle were measured in different concentrations of CAP at TiO2. Liquid Chromatography (LC) is used to CAP with Titanium dioxide mixtures. Mass Spectrometry (MS) can be used for structural identity with high specificity. The MS is also used to analyze CAP from pharmaceutical industrial wastewater. The membranes were subjected to filtration of pharmaceutical wastewater which gave a maximum rejection of 95% of Chloramphenicol.

3D Electrohydrodynamic Printing of Contact Lens‐Like Chloramphenicol‐Loaded Patches for Corneal Abrasions Treatment

Corneal abrasion is a common traumatic emergency, which can cause eyelid photophobia, tearing, and obvious foreign body sensation and pain. Herein, the 3D contact lens‐like chloramphenicol‐loaded patches composed of well‐organized micrometer fibers are prepared via electrohydrodynamic (EHD) printing to treat corneal abrasions. The main material of these patches is cellulose acetate (CA), and chloramphenicol (CAM) is loaded in the patches. EHD printing can realize micrometer fibers stacked layer by layer to form a customizable shape suitable for eye wear. Herein, the surface morphology, chemical as well as physical properties, transparency, drug release behaviors, and biocompatibility of the patches loading various concentrations of CAM are studied. It is found that the CAM‐loaded patches have 3D hemispherical shape similar to contact lens and smooth surface morphology. Moreover, patches loaded with different concentrations of CAM all maintain good water absorption, hydrophilicity, light transmittance, and biocompatibility. The drug release curves of CAM‐loaded patches show that the contact lens‐like patches have high loading efficiency and can achieve sustained release of CAM, indicating clinical potential in the treatment of corneal abrasions.

Application of molecularly imprinted polymers and dual-emission carbon dots hybrid for ratiometric determination of chloramphenicol in milk

Chloramphenicol (CLP) is a veterinary antibiotic that has been banned due to its severe side effects but it is still illegally used in animal husbandry. In this work, the fabrication of simple, fast-response and highly selective ratiometric probe for sensitive visual detection of CLP antibiotic at trace levels in both indoor and outdoor is reported. For the construction of the ratiometric fluorescence probe (mMIP@YBCDs), two kinds of different carbon dots with yellow emission (Y/CDs, 560 nm) and blue emission carbon dots (B/CDs, 440 nm) were used as target sensitive and as reference dyes respectively. Besides, molecularly imprinted mesoporous silica was used as a recognized part of the probe. Upon the addition of different concentrations of CLP, the fluorescence of Y/CDs was quenched significantly while the fluorescence intensity of B/CDs stayed constant which was accompanied by gradual fluorescence color change from yellow-to-blue. The ratiometric probe has a linear response in the range of 0.1–3 μgL−1 with a detection limit 0.035 μgL−1. The practicality of the ratiometric method was validated by the quantification of CLP in milk samples.

Simultaneous Determination of Penicillin G and Chloramphenicol in Milk by a Magnetic Nanoparticle-Based Fluorescent Immunoassay

Background: Antibiotic residues are a problem of increasing importance and have direct consequences for human and animal health. The frequent use of antibiotics in veterinary practice causes their excretion in milk in dairy cattle. This way, they can easily enter the human body through the consumption of milk and dairy products. Objectives: This induces the need for accurate and sensitive methods to monitor antibiotic levels in milk. The aim of this study was to develop a rapid and sensitive magnetic nanoparticle-based fluorescence immunoassay for the simultaneous detection of chloramphenicol and penicillin G in milk. Methods: Magnetic nanoparticles were synthesized and functionalized with (3-aminopropyl)triethoxysilane. Chloramphenicol-Ovalbumin and Chloramphenicol-Ovalbumin-Fluorescein-5-isothiocyanate conjugates were prepared. Penicillin G – ATTO 633 fluorescent conjugate was synthesized. Antibodies against chloramphenicol and penicillin G were immobilized onto the magnetic nanoparticles. The competitive fluorescent immunoassay was developed. The optimal concentration of the antibody-magnetic nanoparticles and the fluorescent conjugates for the assay was determined. The calibration curves for the antibiotics in buffer and milk were plotted. Fluorescent immunoassay for the simultaneous determination of chloramphenicol and penicillin G in milk was developed. Results: The limit of detection by the simultaneous immunoassay of chloramphenicol and penicillin G in milk was 0.85 ng/mL and 1.6 ng/mL, respectively. The recovery of different concentrations of chloramphenicol and penicillin G in milk samples varied from 98% to 106%. Conclusions: A rapid and sensitive magnetic nanoparticle-based immunofluorescent assay for the simultaneous determination of chloramphenicol and penicillin G in milk was developed. The magnetic nanoparticles ensured rapid and easy procedure.

Optimal Allocation of Bacterial Protein Resources under Nonlethal Protein Maturation Stress

Under different environmental stresses, bacteria optimize the allocation of cellular resources through a variety of mechanisms. Recently, researchers have used phenomenological models to quantitatively characterize the allocation of bacterial protein resources under metabolic and translational limitations. Some stresses interfere with protein maturation, thereby enhancing the expression of chaperones and proteases. However, the reallocation of protein resources caused by such environmental stresses has not been modeled quantitatively. Here, we developed a dynamic model of coarse-grained protein resource fluxes based on a self-replicator that includes protein maturation and degradation. Through flux balance analysis, it produces a constrained optimization problem that can be solved analytically. Accordingly, we predicted protein allocation fractions as functions of growth rate under different limitations, which are basically in line with empirical data. We cultured Escherichia coli in media containing different concentrations of chloramphenicol, acetic acid, and paraquat and measured the functional relationship between the expression level of β-galactosidase driven by a constitutive promoter and the bacterial growth rate, respectively. Taking into account the possible mode of stress limitation on the fluxes, our model reproduces this experimentally measured relationship. In addition, our model is in good agreement with the experimental relationship between growth rate and proteome fraction of unnecessary protein in E. coli, considering the unoptimized upregulation of chaperones with useless protein overexpression. The results provide a more systematic view of bacterial stress adaptation that may help in designing for bioengineering or medical interventions.

Novel bioassay using Bacillus megaterium to detect tetracycline in milk

Tetracyclines are used for the prevention and control of dairy cattle diseases. Residues of these drugs can be excreted into milk. Thus, the aim of this study was to develop a microbiological method using Bacillus megaterium to detect tetracyclines (chlortetracycline, oxytetracycline and tetracycline) in milk. In order to approximate the limits of detection of the bioassay to the Maximum Residue Limit (100μg/l) for milk tetracycline, different concentrations of chloramphenicol (0, 1000, 1500 and 2000μg/l) were tested. The detection limits calculated were similar to the Maximum Residue Limits when a bioassay using B. megaterium ATCC 9885 spores (2.8×108spores/ml) and chloramphenicol (2000μg/l) was utilized. This bioassay detects 105μg/l of chlortetracycline, 100μg/l of oxytetracycline and 134μg/l of tetracycline in 5h. Therefore, this method is suitable to be incorporated into a microbiological multi-residue system for the identification of tetracyclines in milk.

Overproduction of a mosquitocidal chloramphenicol-resistant Lysinibacillus sphaericus mutant obtained through UV irradiation

A highly active mosquitocidal mutant UV-chloramphenicol-resistant mutant (UCR-146) of Lysinibacillus sphaericus 2362 was isolated by UV irradiation and selected through resistance to chloramphenicol which was inhibitory for growth of the parent strain. The growth of UCR-146 in NYSMCL at different concentrations of chloramphenicol (20–100 µg/ml) showed high mosquitocidal activity against Culex pipiens larvae with the optimum concentration of 35µg/ml. At this level, LC50 of UCR-146 was decreased about five times from that of L. sphaericus 2362. Comparative efficiency of mosquitocidal activity of UCR-146 and L. sphaericus 2362 within 28 days of consecutive growth exhibited notable stability of both cultures through seven cycles of growth in their optimal media. UCR-146 was grown in industrial by-products media for production of the binary toxin under economic conditions. Offal medium at 2% showed the highest mosquitocidal activity of UCR-146 with LC50 of 0.53 PPM which was 16.6, 13, 12.3 and 3.4 times less than that produced with L. sphaericus 2362 grown in NYSM, L. sphaericus 2362 grown in offal, UCR-146 grown in NYSM and UCR-146 grown in NYSMCL, respectively. Hence, the mosquitocidal activity of L. sphaericus 2362 increased several times through ultraviolet (UV) irradiation followed by chloramphenicol resistance selection and then growth in 2% offal medium. Finally, this procedure for selecting UV-chloramphenicol-resistant mutant and the medium used could potentially be a simple and cost effective approach for obtaining and producing a highly active mosquitocidal mutant.

Effect of antibiotic treatment on the growth and survival of juvenile northern Chilean scallop,Argopecten purpuratusLamarck (1819), and associated microflora in experimental cultures

Juvenile northern Chilean scallops of 937±55 μm shell height were exposed to five different concentrations of chloramphenicol (CHL) (5, 10, 25, 50 and 100 μg mL−1), plus a control without antibiotics. To determine the effect of CHL on the accompanying microflora, the number of colony-forming units (CFU) that grew on TGE culture medium was counted in the seawater of containers with juveniles, and in containers with microalgae used as food. Both were exposed to the same concentrations of CHL. The growth rates of juveniles treated with CHL and the control without antibiotic showed highly significant differences (P=0.0001). The growth rate was inversely proportional to the CHL concentration. The control sample presented the highest growth rate (84.4±14.3 μm day−1), followed by the sample treated with 5 μg mL−1 (64.2±14.3 μm day−1). The survival in the control and in the treated samples with 5–50 μg mL−1 was rather high, with a mean value of 95%. Only the sample treated with 100 μg mL−1 had a low survival (36.7%). The CFU count was larger in the containers with juveniles, when compared with the ones with food. The CFU count tended to decrease with increasing CHL concentration in the juveniles.

Detection of a chloramphenicol efflux system in Escherichia coli isolated from poultry carcass

An active chloramphenicol efflux system was demonstrated in a multiresistant E. coli isolated from poultry carcass. The effect of different concentrations of chloramphenicol on the original strain and on the plasmid-cured strain was determined in the presence and in the absence of CCCP, an uncoupler of the proton-motive force. Minimal inhibitory concentration (MIC) was lower in the presence of CCCP in the original strain. The plasmid-cured strain displayed lower resistance for chloramphenicol than the wild type, but the MIC was not affected by CCCP. The combined results indicate a plasmid encoded energy dependent resistance mechanism. 3H-chloramphenicol accumulation within the cells was measured by scintillation counting. The uptake or the efflux of 3H-chloramphenicol was influenced by CCCP in the original strain, but not in the plasmid-cured strain. More than one chloramphenicol resistance mechanism may exist in this strain. E. coli is an important commensal or pathogen that inhabits the gastrointestinal tracts of humans and animals, so a plasmid encoded active drug resistance mechanism can be a potential source of horizontal transfer of resistance.

Gene amplification in Bacillus subtilis.

A strain of Bacillus subtilis that carries in its genome a staphylococcal chloramphenicol acetyltransferase gene (from pC194) responds to growth at different concentrations of chloramphenicol by an alteration in the number of copies per genome of the sequences encoding the gene. Growth at 20 micrograms chloramphenicol ml-1 results in a 15-fold amplification of the sequences, whereas growth in the absence of chloramphenicol results in their loss. The mechanism of in situ amplification probably has much in common with that involved in 'R factor transitioning'. The hybridization procedures that have been used for accurately determining the number of copies of the amplified DNA sequences are potentially useful for plasmid copy number determination. The findings reported here also provide a potentially useful alternative to more conventional cloning strategies that are based on autonomous plasmids in B. subtilis. The particular advantages that can be envisaged include enhanced stability of the cloned sequences and control of the number of copies that are present.