Chloramphenicol Solution Research Articles

Influence of technological parameters of biological wastewater treatment using lemnaceae on the degree of antibiotic removal

The article is devoted to the study of the effectiveness of the removal of chloramphenicol, a broad-spectrum antibiotic that is often found in the wastewater of pharmaceutical and medical institutions. The aim of the study was to evaluate the efficiency of chloramphenicol removal from model solutions using Lemna minor (duckweed) depending on the initial concentration of the antibiotic, time of cleaning and specific biomass of duckweed. Model solutions of chloramphenicol with concentrations of 2, 5, 10 and 20 mg/L were used in the study. The cleaning time ranged from 1 to 72 hours, and the chloramphenicol content was determined by liquid chromatography. It was established that the efficiency of cleaning depends not only on the time and initial concentration of the antibiotic, but also on the specific biomass of L. minor. In particular, the greatest efficiency was observed in the interval from 24 to 48 hours, after which the removal of the antibiotic markedly decreased, and the content remained stable until the end of the 72-hour period. At chloramphenicol concentrations of 2 and 5 mg/L with a specific duckweed biomass of 36 g/L, the cleaning efficiency gradually increased and reached maximum values in 72 hours of 23.2% and 26.8%, respectively. For a larger biomass – 50 g/L – these indicators were 17% and 19%, which indicates the possible optimization of the cleaning process when reducing the specific biomass of duckweed. At higher initial concentrations of chloramphenicol (10 and 20 mg/L), the use of duckweed with a specific biomass of 36 g/L provided the maximum antibiotic removal of 33.0% and 29.5%, respectively, in 72 hours of purification. As the biomass increased to 50 g/L, the efficiency decreased and amounted to 23.6% and 21% for these concentrations, which indicates the dependence of the process on the amount of L. minor. The results confirm that the use of Lemna minor is promising for the removal of chloramphenicol from wastewater. The highest efficiency was achieved with a process time of 48 hours and a specific duckweed biomass of 36 g/L, which ensured a decrease in the concentration of chloramphenicol to 29.4% at the initial level of 10 mg/L. The use of duckweed contributes to reducing the environmental burden and reduces the risk of the spread of antibiotic resistance in natural waters.

Non-enzymatic rapid sensing platform based on iron doped lead sulfide nano-interfaces for chloramphenicol

The World Health Organization urges strongly to change our needs for the prescription and use of antibiotics. This indicates the severe problem of antibiotic resistance evolving as a universal risk to the masses. Chloramphenicol (CAP) is one such antibiotic, banned internationally, however, it is still being utilized in developing countries due to its low cost and high efficacy. Therefore, routine monitoring of CAP is necessary for humans, food items, and other sources. In this study, lead sulfide (PbS) and different metals [iron (Fe) and cobalt (Co)] doped PbS nanostructures are used for the electrochemical detection of CAP. The PbS nanoparticles and their variants are prepared by the hydrothermal method. Physical, chemical, and surface characterization are done by XRD, SEM, FTIR, PL spectroscopy, and DLS analysis. Under optimum conditions, a quantitative kinetic study for all materials is done in the concentration range of 0.001 μM to 1.5 μM of CAP solution. Fe-doped lead sulfide materials showed a good linear response, sensitivity, and selectivity with a corresponding limit of detection of 0.13 μM (S/N = 3). For selectivity analysis of Fe-doped PbS, chlorfenicol, thiamphenicol, and clindamycin were used as competitors because of their structural and functional similarity with template (CAP) molecules. The electrochemical nano-sensors based on Fe-doped PbS have the potential to detect CAP even in the presence of interfering agents.

Aktivitas Antibakteri Ekstrak Metanol Daun Matenasi (Garcinia Sp.) Terhadap Staphylococcus Aureus dan Eschericia Coli

Medicinal plants are very popular among the people of Indonesia as traditional medicinal ingredients. Traditional medicine is a means of supporting public health for generations, long before formal health services and modern medicines touched the layers of society. One of the medicinal plants which is efficacious as a medicine for diarrhea is matenasi leaf (Garcinia sp). Diarrhea is an infectious disease that often occurs in Indonesia due to Escherichia coli bacteria. This study aims to determine the antibacterial activity of methanol extract using the paper disc diffusion method which is dripped with 10 µl of the test solution using a micro pipette. The concentrations of the methanol extract used were 50%, 75%, and 100% compared to the positive control, namely 30 µl chloramphenicol solution. Matenasi leaves using methanol extract have strong antibacterial activity at a concentration of 100%. For Staphylococcus aureus bacteria with a concentration of 100% with a diameter of 22.67 mm (very strong category), Escherichia coli bacteria with a concentration of 100% with a diameter of 18.25 mm (strong category). The methanol extract of matenasi leaves has the potential as an antibacterial against Stapylococcus aureus and Escherichia coli bacteria.

Boosted chloramphenicol mineralization and detoxification of UV/S(IV) processes with straightforward aeration: The critical contribution of post-reoxygenation

Although advanced reduction processes (ARPs) based on UV/S(IV) (UV/sulfite) processes could achieve higher dechlorination and degradation efficiencies for organic pollutants, the mineralization and detoxification efficiencies still need to be further improved. In this study, post-reoxygenation was employed to improve the mineralization and detoxification of chloramphenicol (CAP) in UV/S(IV)-ARPs. The effects of initial pH and aeration rate on the dechlorination and mineralization efficiency of CAP were investigated. At the optimized conditions (pH 3.0, aeration rate of 0.3 L min−1), 92.75 % of dechlorination efficiency and 29.3 % of COD removal were obtained after 2 h of reoxygenation. Meanwhile, the effects of inorganic anions (Cl-, SO42-, HCO3–, NO3–, and HPO42-) on the removal of COD and dechlorination efficiency were also evaluated. Furthermore, the electron paramagnetic resonance analysis disclosed that SO4•- and HO• mainly contributed to the mineralization of CAP. Further degradation and mineralization of CAP were confirmed in the post-reoxygenation UV/S(IV)-ARPs (PRO-UV/S(IV)-ARPs) and the intermediates were identified. The ecotoxicity prediction and residual toxicity assessment revealed that the ecotoxicity of CAP solution was significantly reduced after the treatment of post-reoxygenation. Overall, the PRO-UV/S(IV)-ARPs provides a promising choice with straightforward operation for the purification and detoxification of CAP wastewater.

Ti/PbO2 Electrode Efficiency in Catalytic Chloramphenicol Degradation and Its Effect on Antibiotic Resistance Genes.

Livestock farming has led to the rapid accumulation of antibiotic resistance genes in the environment. Chloramphenicol (CAP) was chosen as a model compound to investigate its degradation during electrochemical treatment. Ti/PbO2 electrodes were prepared using electrodeposition. The prepared Ti/PbO2-La electrodes had a denser surface and a more complete PbO2 crystal structure. Ti/PbO2-Co electrodes exhibited improved electrochemical catalytic activity and lifetime in practice. The impact of different conditions on the effectiveness of CAP electrochemical degradation was investigated, and the most favorable conditions were identified (current density: I = 15.0 mA/cm, electrolyte concentration: c = 0.125 mol/L, solution pH = 5). Most importantly, we investigated the effects of the different stages of treatment with CAP solutions on the abundance of resistance genes in natural river substrates (intI1, cmlA, cmle3, and cata2). When CAP was completely degraded (100% TOC removal), no effect on resistance gene abundance was observed in the river substrate; incomplete CAP degradation significantly increased the absolute abundance of resistance genes. This suggests that when treating solutions with antibiotics, they must be completely degraded (100% TOC removal) before discharge into the environment to reduce secondary pollution. This study provides insights into the deep treatment of wastewater containing antibiotics and assesses the environmental impact of the resulting treated wastewater.

Simultaneous efficient degradation and dechlorination of chloramphenicol using UV/sulfite reduction: Mechanisms and product toxicity

Chloramphenicol (CAP) is of great concern due to its extensive use and nonnegligible impact on the eco-environment. Herein, the degradation performance and mechanism of CAP by UV/sulfite advanced reduction processes (ARPs) were systematically investigated. 90.67 % degradation efficiency and 92.22 % dechlorination of CAP were simultaneously achieved within 50 min using UV/sulfite-ARPs. The degradation and dechlorination efficiency of the CAP remained elevated with the increase of sulfite concentration, and eventually complete degradation and dechlorination were achieved. Hydrated electrons (eaq−) and direct UV photolysis dominated in the degradation and dechlorination of CAP at pH 5–11. The presence of commonly co-existing anions, humic acid and various water matrices exhibited negligible effect on the CAP degradation and dechlorination efficiencies. Possible degradation pathways of CAP were proposed. Ecotoxicity prediction and seed germination experiments indicated that the acute and chronic ecotoxicity of CAP solution was significantly reduced after the treatment with UV/sulfite-ARPs. Overall, this study demonstrated that UV/sulfite-ARPs could be a promising approach for the CAP purification from wastewaters.

Thermoplastic sago starch nanocomposites wound dressing fortified with antibiotic-modified HNT

Starches were reported to promote wound healing. However, the hydrophilicity of starch help absorbs the exudates from the wounds during the healing process, but it also enables a bacterial infection that slows the healing process. Halloysite nanotubes (HNT) are attracting many biological technologies because of their high loading capacity and biocompatibility. This paper investigates the modified HNT as a carrier for antimicrobials agent in wound healing materials. Halloysite was modified by dispersing it with chloramphenicol solution using a magnetic stirring method. Thermoplastic sago Starch (TPSS)/modified HNT (MHNTs) biocomposite films of different compositions (0.25, 0.5, 0.75 and 1 wt. % HNT) were then developed using the solution casting method. SEM revealed that modified HNT shows good dispersion on the TPSS matrix. With the introduction of modified HNT, the FTIR peaks of TPSS have altered at the peak of 3693.21 cm-1 and 1040.05 cm-1. In addition, modified HNT reduced the water absorption rate of the TPSS films. Furthermore, modified HNT showed good resistance to bacterial culture and significantly reduced the biodegradability rate of TPSS compared to pristine HNT. From the findings, HNT can be a potential carrier for antibacterial agents to withstand bacterial attacks.

Photoelectrocatalytic coupling system synergistically removal of antibiotics and antibiotic resistant bacteria from aquatic environment

Antibiotics, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are ubiquitous in the reclaimed water, posing a potential threat to human and ecological health. Nowadays, the reuse technology of reclaimed water has been widely concerned, but the removal of antibiotics, ARB and ARGs in reclaimed water has not been sufficiently studied. This study used TiO2 nanotube arrays (TNTs) decorated with Ag/SnO2-Sb nanoparticles (TNTs-Ag/SnO2-Sb) as the anode and Ti-Pd/SnO2-Sb as the cathode to construct an efficient photoelectrocatalytic (PEC) system. In this system, 99.9% of ARB was inactivated in 20 min, meanwhile, ARGs was removed within 30 min, and antibiotics were almost completely degraded within 1 h. Furthermore, the effects of system parameters on the removals of antibiotics, ARB and ARGs were also studied. The redox performance of the system was verified by adding persulfate. Escherichia coli, as a representative microorganism in aquatic environments, was used to evaluate the ecotoxicity of PEC treated chloramphenicol (CAP) solution. The ecotoxicity of CAP solution was significantly reduced after being treated by PEC. In addition, transformation intermediates of CAP were identified using liquid chromatography-tandems mass spectrometry (LC-MS/MS) and the possible degradation pathways were proposed. This study could provide a potential alternative method for controlling antibiotic resistance and protecting the quality of reclaimed water.

Antimicrobial Effects of Aqueous Extract from Calyces of Hibiscus sabdariffa in CD-1 Mice Infected with Multidrug-Resistant Enterohemorrhagic Escherichia coli and Salmonella Typhimurium

To determinate the antimicrobial effect of chloramphenicol and aqueous extract against multidrug-resistant enterohemorrhagic Escherichia coli (EHEC) and Salmonella enterica serovar Typhimurium in CD-1 mice. Aqueous extract was isolated from Hibiscus sabdariffa calyces. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of chloramphenicol and aqueous extract were determined for EHEC and S. Typhimurium. Nine groups of six mice each were formed. Three groups were inoculated orally with 1 × 104 colony-forming units (CFU) of S. Typhimurium, three groups were inoculated with 1 × 104 CFU of EHEC and the remaining three groups were not inoculated. Six hours postinoculation, the mice of some groups were orally administered solutions of aqueous extract (50 mg/mL), chloramphenicol (82 μg/mL), or isotonic saline. The EHEC and S. Typhimurium concentration in all mice feces was determined. For both pathogens, the MIC and MBC values of aqueous extract were 20 y 50 mg/mL, respectively; for chloramphenicol, they were between 17.5 and 82 μg/mL. EHEC and S. Typhimurium were not detected in the feces of mice that were administered aqueous extract on the 2nd and 3rd days posttreatment. Furthermore, these mice recovered from the infection. In contrast, in mice not treated, or treated with chloramphenicol alone, pathogens were isolated from their feces throughout the study, and some mice died. The H. sabdariffa calyx extracts could be an alternative to control multidrug-resistant bacteria in humans and animals.

Adsorption of Heavy Metal ions and Antibiotics from Aqueous Solution on Activated Carbons Prepared from Agricultural Waste

The contamination of water by heavy metal ions and antibiotics is presently a serious environmental challenge of the world. This work intends to use activated carbons made out of agricultural waste to alleviate the problem of water pollution. Commercialized coconut shell activated carbon was used for the experiment. Cadmium ions and chloramphenicol were selected as the model compounds for heavy metal and antibiotics in water solution. TOC analyzer and the atomic absorption spectrophotometry were used to determine the concentration of antibiotics and metal ions in solution, respectively. The coconut shell activated carbon turned out to be efficient in the adsorption of metal ions (removal efficiency up to 90% when concentration is 1mg/L) and chloramphenicol (removal efficiency up to 40% when concentration is 1ml/L). The rates of adsorption of both cadmium ions and chloramphenicol were high at first but declined as the contact time increases. The competitive adsorption was investigated in this study by using a mixed solution of cadmium nitrate and chloramphenicol. It was found that the adsorption capacity of chloramphenicol of activated carbon remains the same while the adsorption capacity of metal ions sharply dropped by 44%, indicating that Cadmium ions have no obvious effect on the adsorption of chloramphenicol, whereas chloramphenicol hinders the adsorption of cadmium ions.

Cross-linked Graphene Oxide Framework Membranes with Robust Nano-Channels for Enhanced Sieving Ability.

It remains challenging for graphene oxide (GO) membranes to achieve highly efficient performance and sufficient stability for aqueous molecule/ion precise separations. Herein, a molecular-level rational structure design protocol was proposed to develop ceramic-based graphene oxide framework (GOF) membranes with significantly enhanced sieving performance and stability for efficient removal of salts and micropollutants. Via a molecular cross-linking strategy, interlayered nanochannels between GO nanosheets can be rationally designed, featuring precisely tailorable channel size, promising surface chemistries and remarkably robust stability suitable for aqueous separation. Due to a significantly decreased nanochannel size, cross-linking of TU (thiourea) molecule significantly improved monovalent salt rejection (95.6% for NaCl), outperforming existing state-of-the-art GO-based, commercial organic nanofiltration and emerging two-dimensional MoS2 membranes, while moderately decreasing water permeability. In comparison, the GOF membranes cross-linked with MPD (m-phenylenediamine) exhibited a simultaneous increase in permeability and rejection for both salts and micropollutants (21.0% and 53.3% enhancement for chloramphenicol (CAP) solution), breaking their conventional trade-off issue. Cross-linking mechanism indicates that more robust nanochannels were formed by stronger covalent bonds via dehydration condensation between amine (TU/MPD) and carboxyl groups (GO), and nucleophilic addition between amine (TU/MPD) and epoxy groups (GO). Molecule/ion separation mechanism involved size sieving (steric hindrance), electrostatic interaction, Donnan effect, and partial dehydration effect. This work provides a novel protocol for rationally designing size and surface chemistry of highly robust GO nanochannels at a subnanometer level to construct water-stable functional GOF membranes with enhanced sieving performance for water treatment applications.

Photochemical degradation of chloramphenicol over jarosite/oxalate system: Performance and mechanism investigation

Rational selection of affordable catalyst and effective degradation process are significant for antibiotic-containing wastewater treatment. Herein, a photochemical catalytic system comprising of bio-synthesized jarosite and oxalic acid (Ox) was investigated for degradation of antibiotic chloramphenicol (CAP) under light irradiation. Benefiting from abundant reactive species including H2O2, OH, O2− produced in photochemical process, a 97.5 % removal efficiency of CAP was obtained within 40 min. Consecutive testing cycles indicated jarosite had excellent stability and reusability in photocatalytic system. Radical chain reaction induced by photosensitive Fe(III)-Ox complexes under light irradiation was suggested to be the main mechanism for CAP degradation. A few degradation intermediates were identified to propose the possible degradation pathways of CAP. Further investigation showed that the antibacterial activities of CAP solution towards Escherichia. coli ATCC 8739 and Staphylococcus. aureus ATCC 6538 were largely reduced after treatment by photochemical process. Typical operation parameters of light/jarosite/Ox system were also investigated. CAP degradation performance in actual water demonstrated the feasibility of light/jarosite/Ox process. Overall, the developed light/jarosite/Ox system possesses great potential for antibiotic-containing wastewater treatment.

An electrochemiluminescence aptamer sensor for chloramphenicol based on GO-QDs nanocomposites and enzyme-linked aptamers

In this paper, CdS quantum dots (QDs) were synthesized. Positively charged poly(diallyldimethylammonium chloride) (PDDA) and negatively charged CdS quantum dots were sequentially adsorbed on the surface of graphene oxide (GO). The nano-luminescent materials GO-QDs were prepared and characterized by UV–Vis absorption spectroscopy, fluorescence spectroscopy and transmission electron microscopy. The GO-QDs were then modified on the surface of glassy carbon electrode (GCE). Chloramphenicol aptamer (apt) of 5′-end modified biotin hybridized with the aptamer complementary strand (cDNA) of 5′-end modified amino group into double-stranded DNA (dsDNA). The double-stranded DNA was bonded onto the surface of GO-QDs modified electrode. When the electrode was incubated with streptavidin - labeled horseradish peroxidase (SA-HRP), the biotin modified at the end of the chloramphenicol aptamer can specifically bind directly to the streptavidin labeled HRP. Therefore, HRP was bonded to the surface of the electrode. Hydrogen peroxide was used as the co-reactant of the QDs. HRP can thereby consume hydrogen peroxide and can weaken the electrochemiluminescence intensity. Chloramphenicol in solution can specifically bind to the aptamer to form a composite and to unwind the dsDNA. Then the composite was detached from the surface of the electrode. HRP also left the electrode surface along with the aptamer, so that the electrochemiluminescence signal was significantly enhanced. The electrochemiluminescence intensity of the sensor showed a linear correlation with the logarithm of chloramphenicol concentration. The linear range was 1.0 × 10−12–1.0 × 10−7 M, the detection limit is 0.5 pM. The reproducibility, stability and specificity of the sensor were also studied. The sensor was used for the determination of chloramphenicol in samples and satisfactory results were obtained.

Children’s public health: Danger of exposure to pathogenic fungi in recreational places in the middle-west region of Brazil

BackgroundDermatophytes are keratinophilic fungi, considered etiological agents of cutaneous mycoses in man and animals. The objective of this work was to isolate dermatophytic and non-dermatophytic fungi in recreational sandboxes (rainy and dry periods) in public day-care centers located in the city of Cuiabá-MT (Middle-west of Brazil). MethodsSamples (n=200) were collected from the superficial layer of the sandboxes at a depth of 2–5cm in 10 public nurseries in Cuiabá-MT. Hair baits measuring 1–2cm were autoclaved and dispersed in 50g of the sample in sterile plates, incubated at 28°C, moistened with chloramphenicol solution (50mg/L). After 6 weeks the baits were inoculated on Sabouraud agar plus 50mg/L chloramphenicol and 500mg/L cycloheximide. The fungi were identified according to macroscopic and micromorphological characteristics. ResultsFrom the collected sand samples, 1318 colonies and 56 species of fungi belonging to 22 genera were isolated. The most important genera were Paecilomyces spp. (30.42%), Penicillium spp. (19.12%), Fusarium spp. (11.46%) and Aspergillus spp. (11.15%). Dermatophytes were recovered in 50% of day-care centers in a total of 29 identified colonies, the Trichophyton genus (86.2%) being the most frequently isolated. ConclusionsThe dermatophytes in the recreational areas of day-care centers can pose a risk to the health of its users, especially for children and the employees. Work with this profile is very important to guide actions related to health surveillance.

The use of sea water as a homemade remedy for infectious conjunctivitis-any cause for alarm?

Abstract Aim This study sought to ascertain the usefulness of sea water (SW) in the treatment of infectious conjunctivitis as a homemade medicine. Methods The SW was collected at the sea shore (Gulf of Guinea) in Cape Coast, into a sterile container and kept at 4 °C. This was prepared into different concentrations for assaying in comparison to Normal Saline (NS) and Autoclaved Sea water (AS) which was prepared in the laboratory. The pH, ionic concentration and salinity of SW and NS were determined prior to the antimicrobial assay. Conventional ophthalmic solutions of Chloramphenicol (CH) Gentamycin (Gen), Ciprofloxacin (Cipro) and Tobramycin (Tobra) were used as standards for comparison. The antibacterial susceptibility test was performed against the strains of Staphylococcus spp, Bacillus. spp, Corynebacterium spp, Pseudomonas spp, Haemophilus spp and Klebseilla spp. isolated from clinical cases of infectious conjunctivitis. Minimum inhibition concentrations (MIC) and minimum bactericidal concentration (MBC) were determined for all test agents. Results AS, NS and CH showed bacteriostatic activity against all gram positive bacteria with MIC values of 350–560 µg/mL, 36,000 µg/mL and 5000 µg/mL respectively. NS did the same against only Pseudomonas spp. All Gen, Cipro and Tobra revealed bactericidal activity against all bacteria with MIC and (MBC) value of 3000 µg/mL. However, SW showed no antimicrobial effect but rather introduced other additional bacteria upon subculturing. Conclusion The use of SW as a homemade therapy for infectious conjunctivitis is a risky practice, however, when autoclaved could be beneficial against Gram positive bacteria. Alternatively, normal saline could serve the purpose of first aid homemade therapy for infectious conjunctivitis.

Degradation of chloramphenicol and metronidazole by electro-Fenton process using graphene oxide-Fe3O4 as heterogeneous catalyst

This study investigates the degradation and mineralization of two widely used antibiotics, chloramphenicol and metronidazole, by an electro-Fenton process using graphene oxide-Fe3O4 as a heterogeneous catalyst. The graphene oxide-Fe3O4 composite was typically characterized through conventional spectroscopic and surface analytical methods. The effects of treatment time, pH, catalyst concentration and applied current were examined. In the absence of the graphene oxide-Fe3O4 catalyst (homogeneous environment), the optimum mineralization rates obtained were 57 and 71% at pH 3 and 300 min treatment time for metronidazole and chloramphenicol solutions, respectively. When the optimum graphene oxide-Fe3O4 concentration of 0.5 g L−1 was used, mineralization rates of 73 and 86% were achieved respectively, at the same conditions. This indicated the efficiency of the catalyst and proved that the heterogeneous electro-Fenton process was more effective compared to the homogenous electro-Fenton process. At the same conditions, degradation of chloramphenicol and metronidazole was >99%. The difference between the near-complete antibiotic degradation and the lower mineralization rates, can be justified by the presence of persistent by-products, such as oxalic and glyoxylic acid. Finally, the prepared catalyst showed high levels of reusability and its performance remained practically the same after 4 electro-Fenton runs.

Skrining aktifitas antibakteri dari ekstrak Sisik Naga (Pyyrosia piloselloides (L) M.G.Price)

Abstract
 
 Background : Sisik naga herbs (Pyyrosiapiloselloides (L) M.G. Price) is an epiphyte plants with compounds of flavonoids and tannins. The compound provides antibacterial potency. This plant is effective for wounds, canker sores, constipation and dysentery. The antibacterial activity of the plant is potentially for development of medicinal plant compounds. The extraction process by maceration for 3 days with three repetitions. From 1 kg of weight of Sisik naga obtained 4.95% extract. Antibacterial test using the dilution methods. The results showed the Sisik naga herbs provide antibacterial activity with MIC 256 μg/mL and MBC 512 μg/mL against bacteria Pseudomonas aeruginosa and Staphylococcus aureus. As a positive control used a solution of chloramphenicol.(Objective) This research is aimed to knowing the antibacterial activity of ethanol extracts from Sisik naga hersb. 
 Method : The extraction process by maceration for 3 days with three repetitions with ethanol. Antibacterial avtivity tes by dilution methods. 
 Results :. From 1 kg of Sisik naga obtained 4.95% extract.. The results showed the Sisik naga herbs provide antibacterial activity with MIC 256 μg/mL and MBC 512 μg/mL against bacteria Pseudomonas aeruginosa and Staphylococcus aureus. As a positive control used a solution of chloramphenicol
 Conclusion : herb Sisik naga extracts showed antibacterial activity to Pseudomonas aeruginosae and Staphylococcus aureus
 
 Key words: antibacterial, sisik naga , dilution methods

Insight into the kinetics and mechanism of removal of aqueous chlorinated nitroaromatic antibiotic chloramphenicol by nanoscale zero-valent iron

Nanoscale zero-valent iron (nZVI) is very efficient in removing chlorinated nitroaromatic antibiotic chloramphenicol (CAP) from different waters including DI water, surface water, groundwater, and seawater. The corrosion of nZVI and product distribution after reaction in these water matrices were also investigated. Based on the identification of four main reduction products via HPLC, UPLC-MS/MS, and NMR-H spectrums, a more detailed pathway of CAP degradation by nZVI was proposed than ever reported. The two O atoms on the NO2 group were successively reduced first, and then two Cl atoms were removed via dechlorination. The process of CAP removal could be divided into two stages according to the pseudo-first-order kinetic model. A total of 97.0% of 0.30mM CAP was rapidly removed by 1.8mM nZVI in the first stage (6min) with a surface-area-normalized reaction rate of 1.13Lmin−1m−2. Notably, after reaction with nZVI, the antibacterial activity of the CAP solution was greatly reduced. This study demonstrates that nZVI is a promising alternative to remediate CAP-contaminated water to reduce the antibiotic selection pressure of the environment.

Colorimetric Chemosensor for Chloramphenicol Based on Colloidal Magnetically Assembled Molecularly Imprinted Photonic Crystals

A novel colorimetric chemosensor with good sensitivity, specificity, and self‐reporting capability for chloramphenicol (CAP) has been successfully constructed based on colloidal, magnetically assembled photonic crystals coupled with molecular imprinting. The colloidal, magnetically assembled, molecularly imprinted photonic crystals (CMA‐MIPCs) were prepared by assembling CAP in magnetic, molecularly imprinted nanohydrogels (MMIHs) in a magnetic field. The magnetic assembly of photonic crystals and the sensing processes could be completed simultaneously when MMIHs were dispersed in CAP solutions and in a magnetic field, and the response time was less than 1 min. The CAP concentration could be visually determined from the color change of the CMA‐MIPCs sensor. The diffraction color blue‐shifted from luminous yellow of the blank to purple in a 1.0 mg/mL CAP solution, with a determination limit of 1.0 × 10−3 mg/mL. It could provide a new strategy for qualitative or semiquantitative detection of CAP.

Old drug, new wrapping − A possible comeback for chloramphenicol?

The antimicrobial drug chloramphenicol (CAM) exhibits activity against resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). However, its use has been limited due to its toxicity. As the threat of antibiotic resistance continues to grow, a promising approach might be to increase the use of historical antimicrobial agents that demonstrate clinical efficacy, but are hampered by toxicity. We therefore aimed to prepare a liposome-in-hydrogel system for dermal delivery of CAM. Chitosan (CS) was used as the hydrogel vehicle due to its antimicrobial activity and excellent biocompatibility. All critical preparation steps were carried out by dual centrifugation (DC). The DC-method proved to be fast and simple, and organic solvents were avoided in all processing steps. Liposomes with high drug entrapment (49–56%), low polydispersity and a size of approximately 120nm were produced. Mixing of liposomes into CS-hydrogel by DC produced a homogenous liposomes-in-hydrogel system. Bioadhesive properties were good and comparable to plain CS-hydrogel formulations. Ex vivo permeation studies using pig skin indicated a sustained release of CAM and limited skin permeation. The in vitro antimicrobial activity of CAM in the new liposome-in-hydrogel formulation was similar or better as compared to CAM in solution. Thus, the new formulation was considered highly promising.