Effect of photodynamic therapy with 5-aminolevulinic acid and EDTA-2Na against mixed infection of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa.

BACKGROUND: The increasing abundance of drug-resistant bacteria is a global threat. Photodynamic therapy is an entirely new, non-invasive method for treating infections caused by antibiotic-resistant strains. We previously described the bactericidal effect of photodynamic therapy on infections caused by a single type of bacterium. We showed that gram-positive and gram-negative bacteria could be killed with 5-aminolevulic acid and 410 nm light, respectively. However, clinically, mixed infections are common and difficult to treat. OBJECTIVE: We investigated the bactericidal effects of photodynamic therapy on mixed infections of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. METHODS: We compared bacterial growth with and without photodynamic therapy in vitro. Then, in vivo, we studied mixed infections in a mouse skin ulcer model. We evaluated the rates of ulcer area reduction and transitions to healing in treated and untreated mice. In addition, a comparison was made between PDT and existing topical drugs. RESULTS: We found that photodynamic therapy markedly reduced the growth of both methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa, in culture, and it reduced the skin ulcer areas in mice. PDT was also more effective than existing topical medicines. CONCLUSION: This study showed that photodynamic therapy had antibacterial effects against a mixed infection of gram-positive and gram-negative bacteria, and it promoted skin ulcer healing. These results suggested that photodynamic therapy could be effective in both single- and mixed-bacterial infections.

Effect of photobiomodulation therapy on TGF-ß release from dentin, migration and viability of dental pulp stem cells in regenerative endodontics treatment: An ex vivo study.

BACKGROUND AND AIM: Regenerative endodontic procedures (REPs) are oriented by the principles of tissue engineering, incorporating dental pulp stem cells (DPSC), crucial growth factors like Transforming growth factor-ß (TGF-ß1), and scaffolds to facilitate the regeneration of dental pulp tissues. The present study aimed to investigate the effect of photobiomodulation (PBM) therapy, using an 808 nm diode laser on cellular modulation mechanisms in REPs. METHOD AND MATERIAL: A total of 108 human dentin discs obtained from intact single root teeth were randomly assigned into six groups (n = 8): 1. Positive control (EDTA), 2. PBM-1 (3 J/cm2), 3. PBM-2 (5 J/cm2), 4. EDTA+PBM-1, 5. EDTA+PBM-2, and 6. Negative control (NaOCl). Then, an extract solution was prepared from each disc and the concentration of released TGF-ß1 from the discs was measured using enzyme-linked immunosorbent assay (ELISA). Moreover, the extract solution was added to DPSC culture medium to evaluate cell viability and migration through MTT assay and scratch test, respectively. RESULT: The group exposed to PBM-1 showed the highest cell viability, while treatment with EDTA and EDTA+PBM-2 decreased cellular viability. Also, the PBM-treated groups showed significantly higher release of TGF-ß1 compared to the negative control. EDTA and EDTA+PBM-1 showed the highest release among all the groups. No significant difference was found between EDTA and EDTA+PBM-1, as well as between PBM-1 and PBM-2. Moreover, the PBM-1 group exhibited the highest migration after 24 h, which was significantly greater than other groups, except for the PBM-2 group. CONCLUSION: According to the obtained data, 808 nm mediated-PBM (3 J/cm2), both independently and in conjunction with EDTA, enhanced the release of TGF-ß1 from dentin and improved cell viability and migration of DPSCs. It seems that, PBM under the specific parameters employed in this study, could be an effective adjunctive therapy in REPs.

Potential low-impact immunogen for the production of anti-bothropic serum: Bothrops alternatus venom treated with Na2EDTA.

This study proposes an alternative method using Na2EDTA to neutralize B. alternatus venom and using it as an immunogen from the start of inoculation to minimize side effects and enhance antivenom production. To achieve this, 1.8 mg/mL of B. alternatus venom (B.aV) was treated with Na2EDTA, and any extra chelate was eliminated by filtering the resulting solution through a Sephadex G-25 column. Two groups of BALB/c mice were immunized subcutaneously on days 1, 15 and 30 with B.aV/Na2EDTA (45, 90, 135 µg/mouse) or B.aV (15, 30, 45 µg/mouse), respectively. Both formulations were emulsified with Freund's adjuvant (complete first and incomplete-booster). Blood samples were collected from each mouse on days 14, 29, 41, and 50 post-first immunization, and serum was separated for antibody detection. Animals were then sacrificed and lungs removed for histological analysis (hematoxylin-eosin). Immunoblotting analysis revealed that the sera from mice inoculated with B.aV/Na2EDTA (anti-B.aV/Na2EDTA) recognized the major venom proteins (20-66 kDa) similarly to the sera from mice inoculated with B.aV (anti-B.aV). The enzyme-linked immunosorbent assay results indicated that the anti-B.aV/Na2EDTA had a higher titer (5.76 × 104) than those the anti-B.aV (1.92 × 104). Additionally, sera from animals immunized with B.aV/Na2EDTA significantly neutralized proteolytic, indirect hemolytic and coagulant activity (p < 0.05). Finally, histological examination of the lungs of mice inoculated with B.aV/Na2EDTA showed normal appearance, while animals inoculated with B.aV showed interstitial lung injury (p < 0.05). In conclusion, the B.aV/Na2EDTA formulation, free of excess Na2EDTA, proved to be a promising candidate as an immunogen for antivenom production.

Synergistic action of indole-3-carbinol with membrane-active agents against multidrug-resistant Gram-negative bacteria.

The purpose of this study was to evaluate the antimicrobial activity of indole-3-carbinol (I3C) with membrane-active agents, namely carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and ethylenediaminetetraacetic acid (EDTA) against multidrug-resistant (MDR) Gram-negative bacteria and bacterial persisters. The determination of minimal inhibitory concentration (MIC) showed that I3C was effective against Acinetobacter baumannii (3.13‒6.25 × 10-3 mol l-1), Klebsiella pneumoniae (8 × 10-3 mol l-1), Pseudomonas aeruginosa (6.25‒12.5 × 10-3 mol l-1), and Escherichia coli (6.25‒12.5 × 10-3 mol l-1). Our study demonstrated that EDTA synergistically enhanced the bactericidal activity of I3C against most MDR Gram-negative bacteria isolates and contributed to an 8- to 64-fold MIC reduction compared with that of I3C alone, yet CCCP only displayed synergy with I3C against P. aeruginosa and A. baumannii. The EDTA-I3C combination also significantly reduced the viable number of testing bacteria (P = 7.2E-05), effectively reduced bacterial persisters, and repressed bacterial growth compared with that the use of I3C alone. Our data demonstrate that use of EDTA as adjuvant molecules can effectively improve the antibacterial activity of I3C and may help to reduce the development of antimicrobial resistance.

Pretreatment of Root Dentin Using Photon-Induced Photoacoustic Streaming, Photodynamic Therapy, and Riboflavin with EDTA as a Final Irrigant to Improve Bond Integrity of Glass Fiber Post.

Objective: To evaluate the outcome of post space disinfection using Er,Cr:YSGG laser (ECYL), riboflavin photosensitizer (RFP), and photon-induced photoacoustic streaming (PIPS) along with ethylene diamine tetra acetic acid (EDTA) as final irrigant on the bond values of glass fiber post (GFP) to the canal wall. Materials and methods: Forty human mandibular premolars were subjected to root canal treatment after decoronation till the cementoenamel junction. Post space was prepared using a Gates-Glidden drill leaving 4 mm of gutta perch at the apical third of the root section. Random allocation of samples was performed into four groups based on the post space disinfection (n = 10 each): Group 1: 1% RFP and 17% EDTA, group 2: 5.25% sodium hypochlorite (NaOCl) and 17% EDTA (control), group 3: PIPS and 17% EDTA, and group 4: ECYL and 17% EDTA. GFP was luted using Rely X Unicem. A universal testing machine and stereomicroscope were used to assess the push-out bond strength (PBS) and failure mode, respectively. Analysis of variance determined the PBS amid different experimental groups at three root levels. Multiple group comparison using means of tested groups was identified using post hoc Tukey. Results: The coronal third of group 2 (5.25% NaOCl +17% EDTA) demonstrated the highest PBS (8.83 ± 0.11 MPa). However, the lowest bond integrity (4.15 ± 0.52 MPa) was displayed in an apical third of group 1 (RFP +17% EDTA). The intergroup comparison revealed that 5.25% NaOCl +17% EDTA at all three levels demonstrated comparable outcomes of PBS with PIPS +17% EDTA and ECYL +17% EDTA specimens (p > 0.05). However, riboflavin +17% EDTA demonstrated the lowest bond strength (p < 0.05). Conclusions: Er,Cr: YSGG and PIPS in combination with 17% EDTA demonstrated comparable outcomes of bond score with those of conventional gold standard irrigation regime 5.25% NaOCl.

Comparative evaluation of Sapindus Mukorossi extract with 17% EDTA on smear layer removal in various parts of the tooth root.

OBJECTIVES: This study aimed to compare the effectiveness of an experimental root canal irrigant and 17% Ethylene-di-amine tetra acetic acid for removal of the smear layer in the coronal, middle and apical portions of the root canal. MATERIALS AND METHODS: Ninety human single rooted maxillary and mandibular teeth were selected for this study. The teeth were randomly divided into two experimental groups and one control group as follows: Group A (Ethanolic extract of Sapindus Mukorossi), Group B (17% EDTA), and Group C (Distilled water). The root canals of all three groups were prepared with stainless steel K-files by means of the standard step-back technique and irrigated with 5.25% sodium hypo chloride. The teeth were decoronated, following the irrigation and divided longitudinally into two-halves and visualized using scanning electron microscope (SEM) for the amount of smear layer present utilizing the three-point score system. The observations were noted both before and after the treatment. Nonparametric tests were applied for the comparison and p-value ⩽ 0.05 was considered as statistically significant. RESULTS: It was evident from that smear layer was completely removed in coronal portion of 27 out of 30 teeth in-group A. For middle and apical areas of group A, 24 and 19 teeth showed complete smear layer removal. In-group B it was found that there were 24, 21, and 3 teeth at coronal, middle and apical, areas respectively where smear layer were completely absent. Intra group comparison showed a significant difference (p = 0.002) in smear layer removal was found for group A at coronal, middle and apical thirds. Similarly, a significant difference (p = 0.001) was also found for group B; however heavy smear layer was found among the three parts of the canal for group C. CONCLUSIONS: Ethanolic extract of Sapindus Mukorossi have higher effectiveness in removing the smear layer from the root canal in comparison to 17% EDTA.

Canal pretreatment using cold atmospheric argon plasma, chitosan and Chlorine p6 activated by photodynamic therapy with EDTA as a final irrigant on the pushout bond strength of fiber post.

AIMS: To evaluate the effect of contemporary root canal irrigants i.e., Cold atmospheric argon plasma (CAAP), Chlorine p6 (Clp6), and chitosan on the push-out bond strength (PBS) of glass fiber post (GFP) and marten hardness (MH) of root canal dentin compared to NaOCl+EDTA. MATERIALS AND METHODS: The anatomic crown of sixty human mandibular premolars was removed by transversal section till cement-enamel junction (CEJ). Root canals were prepared and canals were dried and obturated using gutta-percha points and AH plus sealer. Post space was prepared and specimens were arbitrarily divided into four groups based on the post-space irrigation. (n = 15) Group 1: 5.25% NaOCl + 17% EDTA, Group 2: CAAP + 17% EDTA, Group 3: Chitosan + 17% EDTA and Group 4: Clp6 + 17% EDTA. For MH evaluation five samples from each disinfected group were taken and MH was assessed with the help of an ultra microhardness tester. GFP was cemented using self-etch dual cure cement on the remaining 10 samples from each group. Samples were vertically planted in acrylic resin blocks 1 mm thick slices were subjected to push-out testing and failure mode analysis using a universal testing machine and Stereomicroscope. ANOVA and Tukey multiple comparison tests were used to compare the means of bond integrity attained (p = 0.05). RESULTS: The maximum values of PBS and MH were displayed in group 1 (5.25% NaOCl + 17% EDTA) specimens. However, group 3 exhibited the minimum values of bond strength and MH scores. Intergroup comparison analysis revealed that group 2, group 3, and group 4 displayed comparable outcomes of PBS and MH (p > 0.05). The cervical and middle third of group 1 specimens displayed a cohesive type of failure. However, the apical section of group 1 and other tested groups exhibited the adhesive type of failure. CONCLUSION: Canal irrigation with 5.25% NaOCl and 17% EDTA appears to be better in terms of improving the bond integrity of fiber posts with no compromise in MH of the dentin as compared to the contemporary irrigant used.

Bromelain-based endodontic irrigant: preparation, properties, and biocompatibility: An in-vitro study.

The aim of the study was to determine the properties, efficacy and biocompatibility of combining bromelain enzyme, chlorohexidine and EDTA (BCE) to create a novel endodontic irrigant. Fourier transform infrared spectrometry was performed to confirm the stability of the BCE and direct contact inhibition test was performed to determine antibacterial action. Baseline pH and surface tension of irrigants was compared with determine stability. Subcutaneous injection to dorsal skin of rabbits was graded for presence of inflammation, oedema, granulation and fibrosis. BCE caused less overall irritation, less oedematous and was earlier to heal than 2.5% NaOCl. The pH stability of BCE was also superior to 2.5% NaOCl. A one-way ANOVA test was performed for the direct contact inhibition and microleakage test. A significant difference was determined (p ≤ 0.05) between BCE and 2.5% NaOCl for antibacterial action. BCE irrigant is effective in preparing dentinal surfaces for root canal without adverse effects and promising longevity.

Synergistic antibacterial activity of baicalin and EDTA in combination with colistin against colistin-resistant Salmonella.

The emergence and rapid spread of multidrug resistant (MDR) Gram-negative bacteria have posed a serious threat to global health and security. Because of the time-consuming, high cost and high risk of developing new antibiotics, a significant method is to use antibiotic adjuvants to revitalize the existing antibiotics. The purpose of the study is to research the traditional Chinese medicine baicalin with the function of inhibiting the efflux pump and EDTA whether their single or combination can increase the activity of colistin against colistin-resistant Salmonella in vitro and in vivo, and to explore its molecular mechanisms. In vitro antibacterial experiments, we have observed that baicalin and EDTA alone could enhance the antibacterial activity of colistin. At the same time, the combination of baicalin and EDTA also showed a stronger synergistic effect on colistin, reversing the colistin resistance of all Salmonella strains. Molecular docking and RT-PCR results showed that the combination of baicalin and EDTA not only affected the expression of mcr-1, but also was an effective inhibitor of MCR-1. In-depth synergistic mechanism analysis revealed that baicalin and EDTA enhanced colistin activity through multiple pathways, including accelerating the tricarboxylic acid cycle (TCA cycle), inhibiting the bacterial antioxidant system and lipopolysaccharide (LPS) modification, depriving multidrug efflux pump functions and attenuating bacterial virulence. In addition, the combinational therapy of colistin, baicalin and EDTA displayed an obvious reduction in bacterial loads cfus of liver and spleen compared with monotherapy and 2-drug combination therapy. In conclusion, our study indicates that the combination of baicalin and EDTA as a novel colistin adjuvant can provide a reliable basis for formulating the therapeutic regimen for colistin resistant bacterial infection.

Iron Source and Medium pH Affect Nutrient Uptake and Pigment Content in Petunia hybrida 'Madness Red' Cultured In Vitro.

Deficiency or excess of iron (Fe) and improper medium pH will inhibit the growth and development of plants, reduce the transfer and utilization of energy from the root to the leaf, and affect the utilization efficiency of inorganic nutrients. The most common symptom of Fe deficiency in plants is chlorosis of the young leaves. In this study, the effects of the iron source, in combination with the medium pH, on plant growth and development, plant pigment synthesis, and nutrient uptake in a model plant Petunia hybrida cultured in vitro were investigated. Iron sulfate (FeSO4·7H2O) or iron chelated with ethylenediaminetetraacetic acid (Fe-EDTA) were supplemented to the MNS (a multipurpose nutrient solution) medium at a concentration of 2.78 mg·L-1 Fe, and the treatment without any Fe was used as the control. The pH of the agar-solidified medium was adjusted to either 4.70, 5.70, or 6.70 before autoclaving. The experiment was carried out in an environmentally controlled culture room with a temperature of 24 °C with 100 µmol·m-2·s-1 photosynthetic photon flux density (PPFD) supplied by white light emitting diodes (LEDs) during a photoperiod of 16 h a day, 18 °C for 8 h a day in the dark, and 70% relative humidity. Regardless of the Fe source including the control, the greatest number of leaves was observed at pH 4.70. However, the greatest lengths of the leaf and root were observed in the treatment with Fe-EDTA combined with pH 5.70. The contents of the chlorophyll, carotenoid, and anthocyanin decreased with increasing medium pH, and contents of these plant pigments were positively correlated with the leaf color. The highest soluble protein content and activities of APX and CAT were observed in the Fe-EDTA under pH 5.70. However, the GPX activity was the highest in the control under pH 4.70. In addition, the highest contents of ammonium (NH4+) and nitrate (NO3-) were measured in the FeSO4-4.7 and EDTA-5.7, respectively. More than that, the treatment of Fe-EDTA combined with pH 5.70 (EDTA-5.7) enhanced nutrient absorption, as proven by the highest tissue contents of P, K, Ca, Mg, Fe, and Mn. The genes' ferric reduction oxidase 1 and 8 (PhFRO1 and PhFRO8), iron-regulated transporter 1 (PhIRT1), nitrate transporter 2.5 (PhNRT2.5), and deoxyhypusine synthase (PhDHS) were expressed at the highest levels in this treatment as well. In the treatment of EDTA-5.7, the reduction and transport of chelated iron in P. hybrida leaves were enhanced, which also affected the transport of nitrate and catalyzed chlorophyll level in leaves. In conclusion, when the medium pH was adjusted to 5.70, supplementation of chelated Fe-EDTA was more conducive to promoting the growth and development of, and absorption of mineral nutrients by, the plant and the expression of related genes in the leaves.

[Effect of Chelating Agents and Organic Acids on Remediation of Cadmium and Arsenic Complex Contaminated Soil Using Xanthium sibiricum].

In order to improve the phytoextraction efficiency of Xanthium sibiricum on farmland soil that had been contaminated by Cd and As, this study explored the effects of chelating agents and organic acids (EDTA, SAP, CA, and MA) on the extraction of Cd and As heavy metals using X. sibiricum. The results showed that the four different chelating agents and organic acids had little effect on the biomass of the roots, stems, and leaves of X. sibiricum. However, they had different effects on the concentrations and accumulation of Cd and As in various organs of X. sibiricum. Compared with the those in the CK treatment, EDTA, SAP, CA, and MA significantly increased the Cd concentrations in the leaves of X. sibiricum by 44.1%, 32.4%, 41.2%, and 38.2% and the As concentrations in the roots of X. sibiricum by 89.6%, 7.4%, 94.8%, and 61.5%, respectively. The four treatments (EDTA, SAP, CA, and MA) improved the total Cd accumulation of X. sibiricum, with increasing ranges, respectively, of 70.2%, 29.4%, 28.9%, and 33.1%, and the As accumulation increased by 67.0%, 19.6%, 81.9%, and 40.8%, respectively, compared with that of the CK treatment. The four chelating agents and organic acids had different effects on the Cd and As bioconcentration factor and transfer factor of various organs of X. sibiricum. Treatments with EDTA, SAP, CA, and MA resulted in a decrease of 32.7%-38.2% in soil Cd concentrations and a decrease of 14.6%-20.5% in soil As concentrations. These four chelating agents can be used for enhancing the efficiency of extraction Cd and As heavy metals by X. sibiricum.

High prevalence of mgrB-mediated colistin resistance among carbapenem-resistant Klebsiella pneumoniae is associated with biofilm formation, and can be overcome by colistin-EDTA combination therapy.

The global prevalence of colistin-resistant Klebsiella pneumoniae (ColRkp) facilitated by chromosomal and plasmid-mediated Ara4N or PEtN-remodeled LPS alterations has steadily increased with increased colistin usage for treating carbapenem-resistant K. pneumoniae (CRkp). Our study demonstrated the rising trend of ColRkp showing extensively and pandrug-resistant characteristics among CRkp, with a prevalence of 28.5%, which was mediated by chromosomal mgrB, pmrB, or phoQ mutations (91.5%), and plasmid-mediated mcr-1.1, mcr-8.1, mcr-8.2 alone or in conjunction with R256G PmrB (8.5%). Several genetic alterations in mgrB (85.1%) with increased expressions of Ara4N-related phoPQ and pmrK were critical for establishing colistin resistance in our isolates. In this study, we discovered the significant associations between extensively drug-resistant bacteria (XDR) and pandrug-resistant bacteria (PDR) ColRkp in terms of moderate, weak or no biofilm-producing abilities, and altered expressions of virulence factors. These ColRkp would therefore be very challenging to treat, emphasizing for innovative therapy to combat these infections. Regardless of the underlying colistin-resistant mechanisms, colistin-EDTA combination therapy in this study produced potent synergistic effects in both in vitro and in vivo murine bacteremia, with no ColRkp regrowth and improved animal survival, implying the significance of colistin-EDTA combination therapy as systemic therapy for unlocking colistin resistance in ColRkp-associated bacteremia.

Determination of drug efficacy to dissolve cobalt oxide particles in cellular models: Towards a therapeutic approach to decrease pulmonary retention.

Following accidental inhalation of radioactive cobalt particles, the poorly soluble and highly radioactive Co3O4 particles are retained for long periods in lungs. To decrease their retention time is of crucial importance to minimize radiation-induced damage. As dissolved cobalt is quickly transferred to blood and eliminated by urinary excretion, enhancing the dissolution of particles would favor 60Co elimination. We evaluated the ability of ascorbic acid alone or associated with the chelating agents DTPA1, DFOB2 or EDTA3 to enhance dissolution of cobalt particles after macrophage engulfment, and the drug effects on the translocation of the soluble species CoCl2 through an epithelial barrier. We exposed differentiated THP-1 macrophage-like cells and Calu-3 lung epithelial cells cultured in a bicameral system to cobalt and selected molecules up to 7 days. DTPA, the recommended treatment in man, used alone showed no effect, whereas ascorbic acid significantly increased dissolution of Co3O4 particles. An additional efficacy in intracellular particles dissolution was observed for combinations of ascorbic acid with DTPA and EDTA. Except for DFOB, treatments did not significantly modify translocation of dissolved cobalt across the epithelial lung barrier. Our study provides new insights for decorporating strategies following radioactive cobalt particle intake.

An endolysin Salmcide-p1 from bacteriophage fmb-p1 against gram-negative bacteria.

AIMS: A novel endolysin Salmcide-p1 was developed as a promising candidate of new preservative and a supplement to effective enzyme preparations against gram-negative bacterial contaminations. METHODS AND RESULTS: Salmcide-p1 was identified by complementing the genomic sequence of a virulent Salmonella phage fmb-p1. Salmcide-p1 of 112 µg ml-1 could quickly kill Salmonella incubated with 100 mmol l-1 EDTA, with no haemolytic activity. Meanwhile, Salmcide-p1 had a high activity of lysing Salmonella cell wall peptidoglycan. At different temperatures (4-75°C), pH (4-11) and NaCl concentration (10-200 mmol l-1 ), the relative activity of Salmcide-p1 was above 60%. At 4°C, the combination of Salmcide-p1 and EDTA-2Na could inhibit the number of Salmonella Typhimurium CMCC 50115 in skim milk to less than 4 log CFU ml-1 by 3 days, and the number of Shigella flexneri CMCC 51571 was lower than 4 log CFU ml-1 by 9 days. CONCLUSIONS: Salmcide-p1 had a wide bactericidal activity against gram-negative bacteria and showed a broader anti-Salmonella spectrum than the phage fmb-p1. The combination strategy of Salmcide-p1 and EDTA-2Na could significantly inhibit the growth of gram-negative bacteria inoculated in skim milk. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacteriophage endolysin as an antibacterial agent is considered to be a new strategy against bacterial contamination.

In vivo exposure-response relationship of meropenem against metallo-ß-lactamase-harbouring Pseudomonas aeruginosa: an assessment using MICs from conventional and zinc-limited broth.

OBJECTIVES: Previous investigations into metallo-ß-lactamase (MBL)-harbouring Enterobacterales suggest that susceptibility testing in zinc-limited media may be more appropriate in predicting ß-lactam in vivo activity. There are limited data with MBL-harbouring Pseudomonas aeruginosa. METHODS: Forty-three MBL-harbouring P. aeruginosa isolates (IMP, n = 11; VIM, n = 12; NDM, n = 10; SPM, n = 10) and two P. aeruginosa control isolates (KPC, n = 1; WT, n = 1) were evaluated. Meropenem activity was evaluated in the murine neutropenic thigh model using humanized exposures. Susceptibility testing was conducted in conventional CAMHB, EDTA-supplemented CAMHB (3-300 mg/L EDTA) and Chelex-treated CAMHB (0-1.0 mg/L re-supplemented zinc), resulting in a range of meropenem MIC values for each isolate. A sigmoidal Emax model was fitted to fT>MIC versus change in log10 cfu/thigh to estimate the goodness of fit (R2). RESULTS: Increasing EDTA concentrations or limiting the amount of zinc in broth resulted in several-fold reductions in MIC among the majority of the MBL-harbouring P. aeruginosa while the MICs for the KPC and WT isolates were unchanged. Bacterial killing in vivo was variable, with the range of killing spanning -3.29 to +4.81 log10 change in cfu/thigh. Addition of 30 mg/L EDTA and Chelex-treated CAMHB (with no zinc supplementation) provided broth conditions for susceptibility testing that best predicted in vivo efficacy (R2 > 0.7). CONCLUSIONS: Among MBL-harbouring P. aeruginosa, meropenem in vivo efficacy is best represented by the pharmacodynamic profile generated using MICs determined in EDTA-supplemented or zinc-limited broth. In addition to previous data with Enterobacterales, antibiotic susceptibility testing in media that approximates physiological conditions makes it possible to uncover potential and existing therapeutic agents.

Trace mineral source influences digestion, ruminal fermentation, and ruminal copper, zinc, and manganese distribution in steers fed a diet suitable for lactating dairy cows.

High solubility of certain trace minerals (TM) in the rumen can alter nutrient digestibility and fermentation. The objectives of the present studies were to determine the effects of TM source on 1) nutrient digestibility and ruminal fermentation, 2) concentrations of soluble Cu, Zn, and Mn in the rumen following a pulse dose of TM, and 3) Cu, Zn, and Mn binding strength on ruminal digesta using dialysis against a chelating agent in steers fed a diet formulated to meet the requirements of a high producing dairy cow. Twelve Angus steers fitted with ruminal cannulae were adapted to a diet balanced with nutrient concentrations similar to a diet for a high producing lactating dairy cow for 21 d. Steers were then randomly assigned to dietary treatments consisting of 10 mg Cu, 40 mg Mn, and 60 mg Zn/kg DM from either sulfate (STM), hydroxychloride (HTM) or complexed trace minerals (CTM). The experimental design did not include a negative control (no supplemental Cu, Mn, or Zn) because the basal diet did not meet the National Research Council requirement for Cu and Zn. Copper, Mn, and Zn are also generally supplemented to lactating dairy cow diets at concentrations approximating those supplied in the present study. Following a 14-d adaptation period, total fecal output was collected for 5-d. Following the fecal collection period, rumen fluid was collected for Volatile fatty acid (VFA) parameters. On the following day, the same diet was provided for 14 d, without supplemental Cu, Zn, and Mn. This period served as a wash-out period. A pulse dose of 100, 400, and 600 mg of Cu, Zn, Mn, respectively, from either STM, HTM, or CTM, was administered via ruminal cannulae to the steers on day 15. Over a 24-h period ruminal samples were obtained every 2-h. Following centrifugation, the supernatant was analyzed for Cu, Mn, and Zn. Ruminal solid digesta samples from times 0, 12, and 24 h after bolus dosing were exposed to dialysis against Tris-EDTA. Digestibility of NDF and ADF were lesser in STM vs. HTM and vs. CTM supplemented steers. Steers receiving HTM and CTM had greater total VFA concentrations than STM, and molar proportions of individual VFA were not affected by treatment. Ruminal soluble Cu and Zn concentrations were greater post dosing in STM and CTM supplemented steers at 2, 4, and 6 h for Cu and 4, 6, 8, 10 and 12 h for Zn when compared to HTM supplemented steers. The release of Cu and Zn from ruminal solid digesta following dialysis against Tris-EDTA at 12 and 24 h postdosing was greater for steers receiving HTM compared to those receiving STM or CTM. Results indicate trace mineral source impacts: 1) how tightly bound Cu and Zn are to ruminal solid digesta; 2) fiber digestion; 3) and ruminal total VFA concentrations.

Effect of Citric Acid Versus EDTA on Radiographic Root Development in Regenerative Endodontic Treatment: An Animal Study.

INTRODUCTION: Regenerative endodontic treatment was introduced with the aim of reinforcing the root and enabling further root development. In the process of dentin mineralization, bioactive molecules are entrapped in the dentin matrix, which can be released later by rinsing the dentin with chelating agents. This study aimed to compare the effects of citric acid and EDTA on radiographic root development in regenerative endodontic treatment in an animal model. METHODS: Premolars of 3 beagle dogs were used in this study. The teeth at 1 side of the jaw were irrigated with EDTA according to the regeneration protocol of the American Association of Endodontists. The teeth in the other quadrant were irrigated with citric acid in the second treatment session. Follow-up radiographs were obtained at 6 months, and the primary and final data were analyzed in SPSS Version 23 (IBM Corp, Armonk, NY) using the analysis of covariance. RESULTS: There was no significant difference between the 2 irrigating solutions regarding the increase in root length (P = .668); however, EDTA showed significantly superior efficacy in increasing the root dentin thickness compared with citric acid (P = .022). CONCLUSIONS: Within the limitations of this study, the use of citric acid versus EDTA was not superior on radiographic root development in regenerative endodontic treatment.

In vitro evaluation of EDTA combined with photodynamic therapy to reduce Streptococcus mutans in carious dentin.

BACKGROUND: This in vitro study aimed to evaluate the use of EDTA combined with photodynamic therapy to reduce Streptococcus mutans in carious dentin. METHODS: Sixty third molars were sectioned to obtain flat dentin surfaces. All specimens were waterproofed, except for the coronal dentin, and subjected to cariogenic challenge in brain-heart infusion (BHI) broth supplemented with 0.5% yeast extract, 1% glucose, 1% sucrose, and standard strain of S. mutans (ATCC 25175). The specimens were divided into 6 groups (n = 10 each): (1) control - caries collection; (2) EDTA - 17% EDTA was actively applied with a microbrush for 1 min; (3) aPDT - antimicrobial photodynamic therapy with 0.01% methylene blue photosensitizer (wavelength of 660 nm, energy of 4 J, power of 100 mW, spot size of 0.028 cm2, energy density of 142 J/cm2 for 40 s); (4) EDTA+aPDT - 17% EDTA actively applied for 1 min plus aPDT; (5) (EDTA+PT) + L - application of EDTA compounded with photosensitizer plus laser irradiation; and (6) PT - photosensitizer alone. Collection of caries was performed after the different cavity disinfection protocols. Aliquots from each dilution were seeded for colony-forming unit (CFU) counts. The results were log10-transformed and analyzed by the Kruskal-Wallis test (Student-Newman-Keuls). RESULTS: There was a significant reduction in S. mutans after aPDT (p<0.05), EDTA+aPDT (p<0.001), and (EDTA+PT) + L (p<0.001). The percentage of microbial reduction in ascending order was as follows: EDTA: 1.65%; PT: 15.51%; aPDT: 38.28%; EDTA+aPDT: 75.24%; and (EDTA+PT) + L: 97.35%. CONCLUSION: Application of 17% EDTA prior to photosensitization or compounded with a photosensitizer increased the antimicrobial effect of aPDT on S. mutans in carious dentin.

Kanamycin Supplement for the Disaggregation of Platelet Clumps in EDTA-Dependent Pseudothrombocytopenia Specimens.

OBJECTIVE: To indicate the ability to disaggregate platelet clumps by vortex mixing and kanamycin supplementation in EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) specimens. MATERIALS AND METHODS: For patients with EDTA-PTCP, citrate-anticoagulated, primary EDTA-anticoagulated, vortex-mixed, and kanamycin-treated specimens were tested for complete blood count and platelet-related parameters. RESULTS: Forty-eight specimens were included. Nineteen (39.6%) of the vortex-mixed specimens and 42 (87.5%) of the kanamycin-treated specimens revealed platelet counts more than those of the primary EDTA specimens, with levels exceeding 100 × 109/L. The platelet count and platelet recovery of the kanamycin-treated specimens were higher than those of the vortex-mixed specimens. CONCLUSION: Kanamycin supplementation to EDTA-PTCP blood may be considered as an alternative approach when the recollection of specimens is impractical. Only platelet-related parameters from kanamycin treatment were suitable for guiding patient management. Further studies about the impact of these methods in patients with various conditions, such as in patients with advanced kidney disease, should be conducted.

Effect of L-calcium lactate, zinc lactate, and ferric sodium EDTA on the physicochemical and functional properties of liquid whole egg.

The study aimed to evaluate the physicochemical and functional properties of liquid whole egg (LWE) with L-calcium lactate (L-Ca), zinc lactate (L-Zn), and sodium ferric EDTA (NaFeEDTA), and to compare with NaCl addition to determine the application potential of these mineral supplements. Results showed that salts addition significantly influenced the foaming, emulsifying, and gelling properties of LWE, which was possible through affecting the pH, particle size, surface hydrophobicity, apparent viscosity, and solubility. The addition of all the four salts reduced pH but increased the d4,3 diameter of LWE. Additionally, the addition of 200 mM L-Ca and 6 mM L-Zn significantly improved the emulsifying capacity by 41.73% and 13.6%, the foaming capacity by 26.57% and 10%, and the protein solubility by 13.89% and 12.70%, respectively. In the meantime, mineral supplements tend to produce lower hardness gel, especially with 25 mM L-Ca and 8 mM L-Zn, and the hardness was decreased from 2401.13 to 1138.29 and 1175.59 g, respectively. A relative decrease in hardness was desirable in gelled egg products. Moreover, the addition of NaCl and L-Ca showed a higher redness and yellowness, but the addition of NaFeEDTA showed an undesirable color in dark brown, which may be not accepted by the public. In summary, L-Ca and L-Zn had great potential for application in LWE, which was more appropriate than adding NaCl. This study provides a basis for improving the functional properties of LWE products in the future. PRACTICAL APPLICATION: The addition of L-Ca and L-Zn to liquid whole egg (LWE) could improve the foaming and emulsifying capacity of LWE as well as produce a lower hardness gel, which may be more conducive to the production of cake, custards, and meat products. Meantime, it is more in line with people's pursuit of a healthy diet.