EDTA Research Articles

Corrosion mitigation performance of disodium EDTA functionalized chitosan biomacromolecule - Experimental and theoretical approach

Disodium ethylenediaminetetraacetate salt is known for its excellent coordinating properties with the metal ions. The present study deals with the investigation of the prepared Disodium EDTA functionalized chitosan in corrosion inhibition for mild steel in 1 M HCl. The modified chitosan was characterized by spectral studies, thermal analysis, and Zeta potential studies. The corrosion inhibition efficiency (%) was evaluated using the gravimetric method and electrochemical studies. The electrochemical studies included potentiodynamic polarization, linear polarization resistance, and electrochemical impedance methods. The modified chitosan polymer showed an inhibition efficiency of 96.63% for 500 ppm at 303 K. Adsorption process obeyed Langmuir isotherm. Experimental results and theoretical calculations endorsed initial physisorption followed by a chemisorption process. Surface characterization studies supported the formation of a protective film that enabled the inhibition process. Density functional theory, Monte Carlo studies, and molecular dynamics simulation studies show a good agreement with the experimental results. Two-way Analysis of Variance was performed to test the influence of immersion period and inhibitor concentration on the corrosion rate using the statistical software IBM SPSS 20.0. A quartic model was generated as the best fit with the highest R2 value of 0.973. Design Expert software was employed for statistical modeling fit.

Enzyme inhibition and antioxidant functionality of eleven Inula species based on chemical components and chemometric insights

The members of the genus Inula have been widely used in traditional medicinal. In the present study, 11 Inula species were investigated for their phytochemical composition, antioxidant and enzyme inhibitory effects. While quinic acid was the principal compound in I. anatolica, I. britannica, I. inuloides, I. oculus-christi, I. peacockiana, I. sechmenii, I. thapsoides and I. viscidula extracts (22.43–42.02 mg/g dry extract (DE)), I. aucheriana and I. discoidea extracts contained rutin as their most abundant compound (23.28 and 79.10 mg/g extract, respectively). Interestingly, all the Inula extracts were active inhibitors of the five key clinical enzymes (acetylcholinesterase (3.56–5.13 mg galantamine equivalent (GALAE)/g), butyrylcholinesterase (1.49–7.34 mg GALAE/g), tyrosinase (112.31–122.13 mg kojic acid equivalent (KAE)/g), α-glucosidase (0.77–2.08 mmol acarbose equivalent (ACAE)/g) and α-amylase (0.73–0.90 mmol ACAE/g)). Furthermore, the extracts were observed to exhibit substantial antioxidant capacity (1,1-diphenyl-2-picrylhydrazyl (DPPH): 58.99–188.22 mg trolox equivalent (TE)/g); 2,2-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS): 90.51–220.97 mg TE/g; cupric reducing antioxidant capacity (CUPRAC): 169.88–460.53 mg TE/g; ferric reducing antioxidant power (FRAP): 81.57–237.99 mg TE/g; metal chelating activity: 8.31–25.39 mg ethylenediamine tetraacetate equivalent (EDTAE)/g; phosphomolybdenum: 1.55–2.49 mmol TE/g). In conclusion, the Inula species studied herein showed promising pharmacological potentials justified by the presence of a panoply of bioactive compounds.

THE STABILITY OF THE PACKED CELL VOLUME OF ANTICOAGULATED BOVINE BLOOD STORED AT REFRIGERATION TEMPERATURE.

Bovine blood samples with ethylene diamine tetra-acetate (EDTA) or oxalate as anticoagulant were stored at refrigeration temperature of 4°C. The packed cell volume (PCV) was determined daily. During storage, the PCV did not vary significantly. Complete haemolysis, suggested by failure of blood samples to separate into cellular and plasma fractions, started occuring in samples on days 28 and 17, and was observed to have occurred in all samples on days 41 and 24 in blood with EDTA and oxalate respectively.

Analytical measures (tests) recommended before delivery in a labour room for female

The study was conducted at central hospital Saidu Sharif, Swat, Khyber Pakhtunkhwa from April to September 2020. A total of 100 pregnant women belonging to different regions of district Swat were examined, prior to delivery in the research study. The age of the studied participants was 20-45 years. 3ml of venous blood was taken in a sterile syringe (3cc) from each woman and drained in EDTA (Ethylene diamine tetra acetate) tube. The tube was immediately carried to Sheikh-Al-Zahid-bin-Haiyan (casualty) hospital’s laboratory for complete blood count (CBC), Blood sugar (RBS). Human immunodeficiency virus (HIV), HBS-Ag, Hepatitis C virus (HCV), malarial parasites (MP), Brucella and widal test. Urine was also collected in urine bottles for examination and for COVID-19 detection swab samples were taken from nose of the participants. From the recent study it was concluded that pregnant women in the study are susceptible to many diseases and complications. It was found that 12% women were severe anemic while 23% were moderate anemic and 40% were mild anemic. Covid-19 was detected in 12% of the studied women. 2% were observed as HCV positive. 10% of the women had higher blood sugar level (RBS 190mg/dl). 35% of the studied women had a urinary tract infection (UTI). Only 1% of the participant was found to be affected by Brucella bacteria. Malarial parasite was found in almost 5% of the examined participants. HIV was rare and detected in only 1% of the examined one hundred women.

Physiological and histological alterations after post chronic treatment with calcium disodium EDTA on experimental male rats

Physiological and histological alterations after post chronic treatment with calcium disodium EDTA on experimental male rats

Ekscipijensi u inhalacionim lekovima koji mogu izazvati neželjene reakcije

Introduction: In addition to the active pharmaceutical ingredient (API), the composition of the medicines also includes excipients which are only ideally completely pharmacologically inactive. It has been shown that excipients in inhaled preparations can cause effects opposite to the pharmacological effect of the medicine. Aim: The Aim of the study was to identify potentially harmful excipients in inhaled medicines approved in the Republic of Serbia. Material and Methods: The academic study was conducted during April 2021 and included the analysis of medicines that received a marketing authorization from the Medicines and Medical Devices Agency of Serbia (ALIMS). Qualitative compositions of inhaled medicines available in Summaries of product characteristics (SmPC) on the ALIMS's official website were observed. Excipients considered potentially harmful if they are recognised as excipients with known effect (EKE) in Serbian and European regulations. Results: Total of 46 inhalation preparations that are approved in Serbia were analyzed. In their composition were found 17 different excipients. By comparing appropriate domestic and European regulations three excipients from examined preparations that represent potential causative agents of adverse drug reactions (ADRs) were identified: lactose-monohydrate, ethanol and benzalkonium chloride. It has been shown that disodium EDTA is also a potential causative agent of ADRs, but it is not classified as EKE. Conclusion: Neither domestic nor international regulations have classified EDTA and its salts as EKE and they should be given special attention in the future as potential causative agents of ADRs. It has been shown that benzalkonium chloride is the only excipient that can lead to bronchospasm and it was found in two inhaled medicines.

Different WBC count in EDTA caused neutrophil aggregation by hematology analyser

Aggregation of neutrophils in peripheral blood smears is a very rare, mostly self-limiting phenomenon and may result in pseudo leukopenia. The exact reason for neutrophil aggregation in vitro has not been clarified, its relation to the use of ethylene diamine tetra acetate acid as an anticoagulant has been described in adults A 3-year-old boy was referred to Valli e Asr hospital Arak, Iran. The EDTA blood sample was first loaded with the Impedance-based KX-11 Sysmex, which showed a decrease in neutrophils and was observed in the peripheral blood of the Neutrophil aggregation. The blood sample was re-read with the XN-L-350 Sysmex, which is based on the optic method, which showed the number of neutrophils in Norman. Although neutrophil aggregation is extremely rare in daily haematological practice, physicians should be aware of this phenomenon as it may be the cause of leukocytopenia. Therefore, manual differentials should be performed in cases flagged for low leukocyte or neutrophil counts.

Magnetic solid phase extraction of silver-based nanoparticles in aqueous samples: Influence of particle composition and matrix effects on its application to environmental samples and species-selective elution and determination of silver sulphide nanoparticles with sp-ICP-MS

Silver-based nanoparticles (Ag-b-NPs) are currently a cause for concern because they are being produced in increasing quantities for use in industrial goods and consumer products. This goes hand in hand with their release to the environment and the resultant risks for the entire ecosystem. Therefore, it is essential that these materials are monitored. A promising technique that overcomes a number of shortcomings in handling environmental samples is magnetic solid phase extraction (MSPE) of Ag-b-NPs, which is applied in this study. It has been possible to extract different kinds of Ag-b-NPs at environmentally relevant concentrations in the low ng L−1 range using iron oxide magnetic particles (IOMPs) of different size and shape with efficiencies in the range from 80 to 100%. Furthermore, environmentally relevant inorganic ions and TiO2 particles exhibited no major effect on the extraction efficiency. However, natural organic matter (NOM) exhibited a significant influence from 1 mg L−1 resulting in a 50% drop in extraction efficiency. This effect could be overcome by adding 10 mM Ca2+ or increasing the iron oxide magnetic particle (IOMP) concentration to 500 mg L−1. Applying the presented procedure, Ag-b-NPs added to a river water sample at βAg = 50 ng L−1 were successfully extracted. We also investigated the coextraction of Ag+, demonstrating that NOM could eliminate coextraction. The subsequent species-selective elution of Ag2S-NPs after MSPE, was carried out based on ethylene diamine tetraacetate (EDTA) as eluent in different matrices. A desorption efficiency of 76 ± 6% could be achieved while preserving the Ag2S-NPs' size. By contrast, core Ag-NPs and AgCl-NPs are dissolved if the presented method is followed.

Electrodialysis enhanced with disodium EDTA as an innovative method for separating Cu(II) ions from zinc salts in wastewater

In recent years, interest in developing methods for hazardous metal recovery from wastewater has grown steadily within the scientific community. This report describes a method based on electrodialysis enhanced with metal-complex formation to separate cupric ions from zinc sulfate present in a model zinc plating bath. The investigated method can be applied for resource (zinc sulfate) recovery, or to reduce the amount of hazardous galvanic wastes. In this work, the disodium salt of ethylenediaminetetraacetic acid (Na2EDTA) is employed as a complexing agent. The effects of the membrane and current density on the separation efficiency are evaluated and discussed. Finally, the optimal conditions for selective removal of Cu(II) ions from a zinc salt bath are identified, and the effectiveness of the examined method is demonstrated in a batch test. It was determined that, by using thick heterogeneous AM(H)-CM(H) ion-exchange membranes an approximately 13-fold reduction in Cu(II) content, relative to Zn(II), can be achieved at high Zn(II) recovery (94.6%) and current density (220 A/m2). The possibility of applying the described method for concentration of zinc salts in the plating bath was also evaluated. It was shown that Zn(II) content can be increased of up to 1.5 times.

Fenton/ozone-based oxidation and coagulation processes for removing metals (Cu, Ni)-EDTA from plating wastewater

Wastewater containing heavy metals has caused many serious problems to land and marine environments. These heavy metal-laden wastewaters containing organic complexing agents are the consequence of using large-scale industrial applications for dissolving metals. Ethylenediaminetetraacetate (EDTA) is a widely used complexing agent in plating, metal finishing and chemical cleaning industries. However, due to the dramatic increase in the solubility of metal ions, EDTA has negative impact on heavy metals removed in wastewaters by conventional precipitation processes. This study aims to find the optimal conditions of combined/hybrid process of advanced oxidation and coagulation to treat metals-EDTA containing Cu, Ni plating wastewater from an electroplating manufacturer in Vietnam. The effects of pH, H2O2 dose, Fe2+ dose, ozone, reaction time and poly acrylic acid (PAA) dose were investigated. Results indicated that the 3-stage treatment process at the optimal conditions could remove 99.7 % of Ni and 99.72 % of Cu. The effluent of wastewater after the whole treatment process met the Vietnamese national regulation on industrial wastewater (QCVN 40:2011/BTNMT) for NH4+, Cu and Ni at column A and COD at column B. In short, the combined advanced oxidation processes and coagulation/flocculation could successfully be applied for plating wastewater treatment.

Evaluation of ceftriaxone-sulbactam-disodium edetate adjuvant combination against multi-drug resistant Gram-negative organisms.

BackgroundMulti-drug resistant (MDR) Gram-negative bacteria are an emerging threat, both in hospital and community settings. As very few antibiotics are effective against such infections, the need of the hour is a new antibiotic or drug combination which can overcome the effect of extended-spectrum β-lactamases (ESBL) and metallo β-lactamases (MBL). A new antibiotic combination of ceftriaxone, sulbactam and disodium edetate (CSE) has recently been proposed to tackle the MDR organisms.ObjectiveOur study was carried out to assess the susceptibility of ESBL- and MBL-producing Gram-negative organisms to CSE.MethodsThe study was conducted in a tertiary-care hospital in Delhi, India, from February 2017 to June 2017. A total of 179 MDR (85 ESBL + 94 MBL) Gram-negative isolates from various clinical samples, identified by an automated system (Vitek 2) were tested against CSE using the Kirby-Bauer disc diffusion method. Susceptibility to CSE was recorded based on interpretative zone sizes of ceftriaxone as per 2017 Clinical and Laboratory Standards Institute guidelines.ResultsThe most common isolate was Escherichia coli (76/179; 42.4%) followed by Klebsiella pneumoniae (53/179; 29.6%) and Acinetobacter baumanii (27/179; 15.1%). The in vitro susceptibility of ESBL- and MBL-producing Gram-negative isolates to CSE was found to be 58/85 (68.2%) for ESBL and 37/94 (39.4%) for MBL.ConclusionThe in vitro susceptibility results obtained for CSE against ESBL-producing organisms is promising. It has the potential to emerge as a carbapenem-sparing antibiotic, active against ESBL-producing strains. Further clinical studies are required to establish the clinical efficacy of CSE against MDR pathogens.

Study on Electroless Plating Ni-W-P Ternary Alloy with High Tungsten from Compound Complexant Bath

The Ni-W-P alloy coatings have been widely used in the fields of electronic, aviation and anticorrosion, owing to their high hardness, good wear resistance and strong corrosion resistance. Herein, we study the effects of complexants on the chemical composition, morphology and plating rate of the Ni-W-P ternary alloy coatings by developing a near-neutral plating solution with disodium edetate, sodium citrate and lactic acid as complex complexants. The results of scanning electron microscope (SEM) and energy-dispersive spectrometer (EDS) indicate that a flat and dense coating with the W content up to 11.75 wt.% is acquired by adjusting the composition of plating solution. Meanwhile, the plating rate of Ni-W-P coating can reach up to 22.4 µm/h. Furthermore, the characterization results indicate that the Ni-W-P ternary alloy coating possesses higher hardness, better wear and corrosion resistance compared to Ni-P coating. These findings may exploit a broader field for searching better complexants in electroless coating and for understanding the related mechanisms to provide guidance for the design of ternary alloy coatings.

Rates and Dynamics of Mercury Isotope Exchange between Dissolved Elemental Hg(0) and Hg(II) Bound to Organic and Inorganic Ligands.

Mercury (Hg) isotope exchange is a common process in biogeochemical transformations of Hg in the environment, but it is unclear whether and at what rates dissolved elemental Hg(0)aq may exchange with divalent Hg(II) bound to various organic and inorganic ligands in water. Using enriched stable isotopes, we investigated the rates and dynamics of isotope exchange between 202Hg(0)aq and 201Hg(II) bound to organic and inorganic ligands with varying chemical structures and binding affinities. Time-dependent exchange reactions were followed by isotope compositional changes using both inductively coupled plasma mass spectrometry and Zeeman cold vapor atomic absorption spectrometry. Rapid, spontaneous isotope exchange (<1 h) was observed between 202Hg(0)aq and 201Hg(II) bound to chloride (Cl-), ethylenediaminetetraacetate (EDTA), and thiols, such as cysteine (CYS), glutathione (GSH), and 2,3-dimercaptopropanesulfonic acid (DMPS) at a thiol ligand-to-Hg(II) molar ratio of 1:1. Without external reductants or oxidants, the exchange resulted in transfer of two electrons and redistribution of Hg isotopes bound to the ligand but no net changes of chemical species in the system. However, an increase in the ligand-to-Hg(II) ratio decreased the exchange rates due to the formation of 2:1 or higher thiol:Hg(II) chelated complexes, but had no effects on exchange rates with 201Hg(II) bound to EDTA or Cl-. The exchange between 202Hg(0)aq and 201Hg(II) bound to dissolved organic matter (DOM) showed an initially rapid followed by a slower exchange rate, likely resulting from Hg(II) complexation with both low- and high-affinity binding functional groups on DOM (e.g., carboxylates vs bidentate thiolates). These results demonstrate that Hg(0)aq readily exchanges with Hg(II) bound to various ligands and highlight the importance of considering exchange reactions in experimental enriched Hg isotope tracer studies or in natural abundance Hg isotope studies in environmental matrices.

Using loose nanofiltration membrane for lake water treatment: A pilot study

Nanofiltration (NF) using loose membranes has a high application potential for advanced treatment of drinking water by selectively removing contaminants from the water, while membrane fouling remains one of the biggest problems of the process. This paper reported a seven-month pilot study of using a loose NF membrane to treat a sand filtration effluent which had a relatively high turbidity (∼0.4 NTU) and high concentrations of organic matter (up to 5 mg/L as TOC), hardness and sulfate. Results showed that the membrane demonstrated a high rejection of TOC (by<90%) and a moderately high rejection of two pesticides (54%–82%) while a moderate rejection of both calcium and magnesium (∼45%) and a low rejection of total dissolved solids (∼27%). The membrane elements suffered from severe membrane fouling, with the membrane permeance decreased by 70% after 85 days operation. The membrane fouling was dominated by organic fouling, while biological fouling was moderate. Inorganic fouling was mainly caused by deposition of aluminum-bearing substances. Though inorganic foulants were minor contents on membrane, their contribution to overall membrane fouling was substantial. Membrane fouling was not uniform on membrane. While contents of organic and inorganic foulants were the highest at the inlet and outlet region, respectively, the severity of membrane fouling increased from the inlet to the outlet region of membrane element with a difference higher than 30%. While alkaline cleaning was not effective in removing the membrane foulants, the use of ethylenediamine tetraacetate (EDTA) at alkaline conditions could effectively restore the membrane permeance.

Efeito do hipoclorito de sódio na retenção de pinos de fibra de vidro – revisão de literatura

O objetivo desse trabalho foi realizar uma revisão de literatura sobre o efeito do hipoclorito de sódio na retenção de pinos de fibra de vidro. Uma busca por artigos foi feita em bases eletrônicas de dados (Pubmed, Bireme e Scielo). Os resumos foram selecionados de acordo com o tema proposto, baixados e lidos para inserir no trabalho somente os pontos principais de cada trabalho e, assim, formular a revisão de literatura com informações atuais sobre o assunto proposto. A discussão foi realizada para compreender os resultados e chegar a considerações finais da revisão fazendo uma conexão com a prática clínica. As conclusões foram baseadas na hipótese de que o hipoclorito de sódio tem efeito negativo na retenção de pinos de fibra de vidro. A presente revisão de literatura mostrou, a partir dos achados dos estudos, que o uso do hipoclorito de sódio pode interferir na retenção de pinos de fibra de vidro ao canal radicular, principalmente quando a irrigação final com EDTA 17% não é realizada.

Reduction of uranyl and uranyl-organic complexes mediated by magnetite and ilmenite: A combined electrochemical AFM and DFT study

Reduction of mobile aqueous uranyl complexes can be hindered by the strength of the uranyl-ligand complex and the resistivity of the complexes to electron transfer. Semiconducting solids, such as magnetite (Fe3O4) and ilmenite (FeTiO3), can facilitate otherwise-slow electron transfer between the reductant and oxidant, especially if these species are adsorbed on their surfaces as inner-sphere complexes. Electrons can then be shuttled through the surface or the structure. This process can be facilitated by either finding a new electron transfer path or by weakening or destroying the ligand-uranyl complex.Using in situ electrochemical atomic force microscopy (EC-AFM), we imaged reduction products of uranyl as mediated by magnetite and ilmenite in the absence or presence of the organic ligands, ethylenediaminetetraacetate (EDTA) and oxalate. In situ images of uranyl reduction show gradual nucleation and growth of reduced uranium on the mineral surfaces with decreasing reduction potentials. X-ray photoelectron spectroscopy (XPS) measurements indicate pentavalent uranium as the dominant uranium species resulting from uranyl reduction mediated by magnetite and ilmenite. The reduction potentials of uranyl-organic species relevant to our reaction system, (UVIO2∙oxalate)0 and (UVIO2∙HEDTA)−, are derived using quantum–mechanical modeling and compared with the midpoint potentials obtained from cyclic voltammetry measurements. The spectroscopic, electrochemical, and computational data suggest that the catalysis of Fe-bearing minerals facilitates the reduction of uranyl-organic complexes. U(VI)-oxalate complexes are redox-active and participate directly in the reduction mediated by magnetite. In the presence of EDTA, reduction of uranyl may proceed in concert with ligand exchange between metals (i.e., U and Fe) on the mineral surface. The proposed mechanism is the breaking of uranyl-organic bonds upon interaction with the mineral surface followed by the formation of Fe-organic bonds, thereby allowing the reduction of hexavalent uranyl to pentavalent one.

Pilot scale water free dyeing of pure cotton under supercritical carbon dioxide

Supercritical carbon dioxide (scCO2) is a green, safe and environmentally friendly medium in textile dyeing. It is, indeed representing a salient advancement in modern dyeing of textiles. However, to the authors' knowledge, current methods of dyeing 100% unmodified cotton fabrics under supercritical medium up to pilot scale encounter many problems, challenges and a variety of severe shortages. Thus, the aim of the current work is to develop a method for dyeing unmodified 100% cotton fabrics using vinyl sulphone reactive disperse dye under scCO2. Two types of cotton (woven & knitted) fabrics were dyed with N,N‑diethyl-4-((4-vinylsulfonyl)phenyl)diazenylaniline disperse reactive dye, in the presence of disodium edetate as a swelling agent under scCO2. The results indicate that vinyl sulphone dye has high color strength (K/S) values on cotton fabrics using the organic electrolyte (disodium edetate). The system parameters, mainly temperature, pressure, time were investigated. The proposed methodology has been confirmed by carrying out a pilot-scale experiment using the optimum conditions obtained from lab-scale. The results proved that dyeing cotton under scCO2 medium on pilot level is possible. However, more efforts are needed to develop more dyestuffs with different colors that suitable for cotton dyeing.

Statistical optimization of culture medium composition for enhanced zeaxanthin production by Cyanophycean microalgae Trichodesmium thiebautii (NIOT 152)

Background/Objectives: Zeaxanthin is a xanthophyll carotenoid revered for its role in the prevention of age related macular degeneration. The study evaluated the zeaxanthin accumulation of the marine Cyanophycean alga Trichodesmium thiebautii (NIOT 152). A sequential statistical technique was applied to optimize the Artificial Sea Water nutrient medium (ASN-III) components for enhancing the zeaxanthin accumulation in T. thiebautii. Methods: A two-level statistical approach involving Plackett-Burman (PB) design to screen the most important nutrients influencing the zeaxanthin accumulation followed by Response surface methodology (RSM) was employed. The results of PB design revealed sodium nitrate, disodium EDTA, magnesium sulphate and sodium carbonate as the crucial medium components for increasing zeaxanthin accumulation. Further, RSM was employed to study the interaction between these factors and identified an optimum concentration of the ingredients for higher zeaxanthin production. Findings: The optimized medium components resulted in 2.33 fold increase in zeaxanthin accumulation (4.3 ± 1.29 mg L-1) as compared to ASN III medium (1.84 ± 0.12 mg L-1). Novelty: There are only few studies on laboratory cultured Trichodesmium and only very few reports are available regarding pigment production from Trichodesmium sp. The present study successfully demonstrated the statistical optimization of ASN III medium to improve zeaxanthin accumulation by Trichodesmium thiebautii. Keywords: ASN III medium; zeaxanthin; Trichodesmium thiebautii; Plackett-Burman; response surface methodology REFERENCE

Isolation of Antibiotic-Producing Bacteria from Extreme Microhabitates in Mangrove Ecosystem

This study aims to isolate and identify the antibiotic-producing bacteria from extreme microhabitates in the marine ecosystem against fish pathogenic bacteria (V. alginolyticus, A. hydrophila, dan Pseudomonas sp). Microbes from samples were grown on NA and TSA media. Well grown colonies were examined for their ability to produce antibiotics against the pathogens by the streaking and paperdisc diffusion method on MHA. Potential isolates were identified through a series of phenotypic and genotypic test. A number of 4 antibiotic-producing bacteria were selected. DNA of the bacteria were extracted using DNA easy mini column and amplified by using Kappa PCR kit with 16S rDNA 1A and 16S rDNA2A primers. The PCR results were analyzed on a 1.5% agarose gel in Tris-acetat-EDTA (TAE) electrophoresisuffer (4 mM Tris-acetate and 1 mM disodium EDTA at pH 8.0). The electrophoresis process was carried out at 60 mA (100-120 v) for 30-45 minutes read by UV Transilluminator. Isolate Ni5 have a 99% homological similarity to Bacillus amyloliquefaciens strain SH20. Bacterial isolate Xy3 has a 100% homological similarity with Bacillus cereus strain NY180. Isolate S11 has a 97% homological similarity with Enterobacter hormaechei strain CGAPGPBBS-064. Isolate K22 has a 99% homological resemblance to Klebsiella pneumoniae strain MW-W 754.

A new ophthalmic formulation containing antiseptics and dexpanthenol: In vitro antimicrobial activity and effects on corneal and conjunctival epithelial cells

Antibiotic resistance is increasing even in ocular pathogens, therefore the interest towards antiseptics in Ophthalmology is growing. The aim of this study was to analyze the in vitro antimicrobial efficacy and the in vitro effects of an ophthalmic formulation containing hexamidine diisethionate 0.05%, polyhexamethylene biguanide (PHMB) 0.0001% disodium edetate (EDTA) 0.01%, dexpanthenol 5% and polyvinyl alcohol 1.25% (Keratosept, Bruschettini, Genova, Italy) on cultured human corneal and conjunctival cells. The in vitro antimicrobial activity was tested on Staphylococcus aureus, Methicillin-Resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Streptococcus pneumoniae, Streptococcus pyogenes and Streptococcus mitis. For each microbial strain 10 μL of a 0.5 MacFarland standardized bacterial inoculum were incubated at 25 °C with 100 μL of ophthalmic solution for up to 6 h. After different periods of time, samples were inoculated on blood agar with 5% sheep blood. Moreover, a 0.5 MacFarland bacterial inoculum was seeded in triplicate on Mueller-Hinton Agar or on Mueller-Hinton Fastidious Agar; then a cellulose disc soaked with 50 μL of ophthalmic solution was applied on the surface of agar and plates were incubated for 18 h at 37 °C, in order to evaluate the inhibition of bacterial growth around the disc. Human corneal and conjunctival epithelial cells in vitro were incubated for 5, 10 and 15 min with Keratosept or its components. The cytotoxicity was assessed through the release of cytoplasmic enzyme lactate dehydrogenase (LDH) into the medium immediately after exposure to the drugs; the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate the metabolic cell activity. Our results show that Keratosept ophthalmic solution gave an average logarithmic (log) reduction of bacterial load of 2.14 ± 0.35 within 6 h of exposure (p-value < 0.05 versus control saline solution). On agar plates, all microbial strains, excluding P. Aeruginosa, showed an inhibition zone of growth around the Keratosept-soaked discs. Keratosept and its components after 5 and 10 min did not show any cytotoxic effect on cultured corneal and conjunctival cells, and only after 15 min a significant reduction of cell viability and an increase of cytotoxicity compared to control (vehicle) was seen; dexpanthenol 5% and polyvinyl alcohol accelerated the wounding of corneal cells in vitro. In conclusion, Keratosept showed good antimicrobial activity on the tested strains; the ophthalmic solution and its components were safe and non-toxic for the corneal and conjunctival epithelial cells for 5 and 10 min at the concentrations analyzed, and dexpanthenol 5% and polyvinyl alcohol promoted the wounding of corneal cells.