scholarly journals The α-Cyclodextrin/Moringin Complex: A New Promising Antimicrobial Agent against Staphylococcus aureus

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2097 ◽  
Author(s):  
Letizia Romeo ◽  
Veronica Lanza Cariccio ◽  
Renato Iori ◽  
Patrick Rollin ◽  
Placido Bramanti ◽  
...  
Keyword(s):  
Antimicrobial Agent ◽  
Moringa Oleifera ◽  
Therapeutic Strategy ◽  
Inhibitory Concentration ◽  
Antimicrobial Effect ◽  
Aureus Strain ◽  
Antimicrobial Drugs ◽  
Bactericidal Properties ◽  
Mic Minimum Inhibitory Concentration ◽  
Reference Strains

Antimicrobial resistance is one of the major clinical concerns, making the discovery of new antimicrobial drugs desirable. Moringin (MOR), the major isothiocyanate produced from Moringa oleifera seeds, could represent an alternative therapeutic strategy to commonly used antibiotics. The aim of our study was to investigate the antimicrobial effect of MOR conjugated with α-cyclodextrin (MOR/α-CD), a complex with an improved solubility and stability in aqueous solutions. Our data demonstrated that MOR/α-CD was able to exert antimicrobial activity against the S. aureus reference strains (ATCC 25923, ATCC 6538, and ATCC BAA-977). Moreover, MOR/α-CD showed bacteriostatic effects (MIC = minimum inhibitory concentration = 0.5 mg/mL) and bactericidal properties (MBC = minimum bactericidal concentration = 1 mg/mL) against the overall assessed strains. In addition, MOR/α-CD showed bactericidal activity against the S. aureus strain ATCC BAA-977 after treatment with erythromycin (Ery), which induced clindamycin-resistance on the erm (A) gene. This evidence led us to assume that MOR/α-CD could be a promising antimicrobial agent against strains with the clindamycin-resistant phenotype (CC-resistant).

INVESTIGAÇÃO DA AÇÃO ANTIMICROBIANA DO LÁTEX DE MANGABEIRA EM DUAS CEPAS DE BACTÉRIAS CAUSADORAS DE PNEUMONIA

2018 ◽  
Vol 4 ◽  
Author(s):  
Enéas Costa Junior ◽  
Anderson Da Cunha Costa ◽  
Kivia Ludmilla Carvalho Ferreira ◽  
Kelly Maria Rêgo da Silva ◽  
Ester Miranda Pereira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Antimicrobial Effect ◽  
Antimicrobial Action ◽  
Aureus Strain ◽  
Total Inhibition ◽  
Two Samples ◽  
Hancornia Speciosa

Objective: To evaluate the antimicrobial action of latex of Hancornia speciosa in two strains of bacteria causing Pneumonia. Method: The latex was collected and divided into two samples, a sample diluted in 5 mL of distilled water and dissolved in pure latex. The latex was then submitted to the Minimum Inhibitory Concentration (MIC) test, evaluating the lowest concentration capable of inhibiting the growth of strains of Staphylococcus aureus and Escherichia coli. Results: The Minimum Inhibitory Concentration test showed that the diluted latex had no antimicrobial effect in the Staphylococcus aureus strain and showed total inhibition of Escherichia coli growth. In the latex, in its pure form, showed growth in the first three dilutions tested and total inhibition in the others, behaving equally for both Staphylococcus aureus and Escherichia coli. Conclusion: Latex has antimicrobial action and low toxicity.

IDENTIFICATION AND ANTIMICROBIAL ACTIVITY OF ACTINOMYCETES STRAINS ISOLATED FROM SAMPLES IN THE COASTAL AREA OF THANH HOA – QUANG BINH – QUANG TRI

2018 ◽  
Vol 56 (4) ◽  
pp. 424
Author(s):  
Le Thi Hong Minh ◽  
Vu Thi Quyen
Keyword(s):  
Antimicrobial Activity ◽  
Inhibitory Concentration ◽  
Rrna Gene ◽  
Soft Corals ◽  
16S Rrna Gene Sequences ◽  
Reduced Pressure ◽  
Genus Streptomyces ◽  
Mic Minimum Inhibitory Concentration ◽  
Fermentation Broths ◽  
Reference Strains

In this study, we isolated 46 strains of actinomycetes from 40 samples including: sediments, sponges, soft corals, echinoderms and starfish collected from three sea areas of Vietnam: Thanh Hoa – Quang Binh – Quang Tri. The strains were fermented in A+ medium and fermentation broths were extracted 5 times with ethyl acetate then the extracts were evaporated under reduced  pressure to yield crude extracts. Quantitative assay was used to determine MIC (Minimum inhibitory concentration) of extract against 7 reference strains. From the results of screening, we chose 5 strains of actinomycetes that have the highest biological activity (Code: G212, G222, G233, G227 and G241). In particular,  strains G222, G233, G227 and G241 were resistant 6/7 strains of microorganisms test, with values  MICs from 64µg/ml to 256µg/ml; Moreover, All of the five strains were highly resistant to yeast Candida albicans ATCC10231. These strains were then subjected to morphological and phylogenetic investigations based on 16S rRNA gene sequences. The results showed that strains G212, G222 and G227 belonged to Genus Streptomyces; strains G233 and G241 were identified as Genus Micromonospora.

Effectiveness of ZnO Nano Particles against the Foodborne Microbial Pathogens E. coli and S. aureus

2020 ◽  
Vol 15 (2) ◽  
pp. 87-94
Keyword(s):  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Antimicrobial Effect ◽  
Nano Particles ◽  
Microbial Pathogens ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests

In this work, various concentrations of ZnO nano particles, prepared by the coprecipitation method with a size range of 47-68 nm, have been investigated as antimicrobial agents. Dilution antimicrobial susceptibility tests were carried out on two kinds of microbes (Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli) according to the standard method recommended by Clinical and Laboratory Standards Institute, CLSI-2015-M07-A10. The results showed that the antimicrobial effect is larger, the higher the concentration of ZnO nano particles in solution. It was also found that Gram-positive microbes are more sensitive to ZnO nano particles when compared with the Gram-negative ones. The minimum inhibitory concentration (MIC) for E. coli was found to be 50 mg/mL while that for S. aureus was 25 mg/mL. The minimum bactericidal concentration (MBC) was 1600 mg/mL for E. coli and 800 mg/mL for S. aureus.

scholarly journals Cytotoxic Potential of the Novel Horseshoe Crab Peptide Polyphemusin III

Marine Drugs ◽  
2018 ◽  
Vol 16 (12) ◽  
pp. 466 ◽  
Author(s):  
Mariana Marggraf ◽  
Pavel Panteleev ◽  
Anna Emelianova ◽  
Maxim Sorokin ◽  
Ilia Bolosov ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Horseshoe Crab ◽  
Inhibitory Concentration ◽  
Human Cancer ◽  
Membrane Integrity ◽  
Antimicrobial Effect ◽  
Human Leukemia ◽  
Bacterial Strains ◽  
Trypan Blue Exclusion

Biological activity of the new antimicrobial peptide polyphemusin III from the horseshoe crab Limulus polyphemus was examined against bacterial strains and human cancer, transformed, and normal cell cultures. Polyphemusin III has the amino acid sequence RRGCFRVCYRGFCFQRCR and is homologous to other β-hairpin peptides from the horseshoe crab. Antimicrobial activity of the peptide was evaluated and MIC (minimal inhibitory concentration) values were determined. IC50 (half-maximal inhibitory concentration) values measured toward human cells revealed that polyphemusin III showed a potent cytotoxic activity at concentrations of <10 μM. Polyphemusin III caused fast permeabilization of the cytoplasmic membrane of human leukemia cells HL-60, which was measured with trypan blue exclusion assay and lactate dehydrogenase-release assay. Flow cytometry experiments for annexin V-FITC/ propidium iodide double staining revealed that the caspase inhibitor, Z-VAD-FMK, did not abrogate disruption of the plasma membrane by polyphemusin III. Our data suggest that polyphemusin III disrupts the plasma membrane integrity and induces cell death that is apparently not related to apoptosis. In comparison to known polyphemusins and tachyplesins, polyphemusin III demonstrates a similar or lower antimicrobial effect, but significantly higher cytotoxicity against human cancer and transformed cells in vitro.

scholarly journals Antimicrobial Efficacy of Fruit Peels Eco-Enzyme against Enterococcus faecalis: An In Vitro Study

2020 ◽  
Vol 17 (14) ◽  
pp. 5107
Author(s):  
Hetal Ashvin Kumar Mavani ◽  
In Meei Tew ◽  
Lishen Wong ◽  
Hsu Zenn Yew ◽  
Alida Mahyuddin ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Inhibitory Concentration ◽  
Antimicrobial Properties ◽  
In Vitro Study ◽  
Antimicrobial Effect ◽  
Antimicrobial Efficacy ◽  
Significant Difference ◽  
Potential Alternative ◽  
The One

Sodium hypochlorite (NaOCl), an effective endodontic irrigant against Enterococcus faecalis (EF), is harmful to periapical tissues. Natural pineapple-orange eco-enzymes (M-EE) and papaya eco-enzyme (P-EE) could be potential alternatives. This study aimed to assess the antimicrobial efficacy of M-EE and P-EE at different concentrations and fermentation periods against EF, compared to 2.5% NaOCl. Fermented M-EE and P-EE (3 and 6 months) at various concentrations were mixed with EF in a 96-well plate incubated for 24 h anaerobically. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of M-EE and P-EE were determined via EF growth observation. EF inhibition was quantitatively measured and compared between different irrigants using the one-way analysis of variance (ANOVA), and different fermentation periods using the independent-samples T-test. M-EE and P-EE showed MIC at 50% and MBC at 100% concentrations. There was no significant difference in antimicrobial effect when comparing M-EE and P-EE at 50% and 100% to 2.5% NaOCl. P-EE at 6 months fermentation exhibited higher EF inhibition compared to 3 months at concentrations of 25% (p = 0.017) and 0.78% (p = 0.009). The antimicrobial properties of M-EE and P-EE, at both 100% and 50% concentrations, are comparable to 2.5% NaOCl. They could therefore be potential alternative endodontic irrigants, but further studies are required.

scholarly journals Antimicrobial Effect of Platelet-Rich Plasma againstPorphyromonas gingivalis

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Thuy Anh Vu Pham ◽  
Thao Thi Phuong Tran ◽  
Ngan Thi My Luong
Keyword(s):  
Chronic Periodontitis ◽  
Inhibitory Concentration ◽  
Platelet Rich Plasma ◽  
Antibacterial Properties ◽  
Antimicrobial Effect ◽  
Disk Surface ◽  
Subgingival Plaque ◽  
Bacterial Identification ◽  
Severe Periodontitis ◽  
Susceptibility Assay

Aim. The aim of our study was to evaluate whether there was a difference in antimicrobial effect between the PRP of healthy volunteers and that of patients with chronic periodontitis againstP. gingivalis,which was fresh cultured from subgingival plaque.Methods. Subgingival plaque of patients with moderate and severe chronic periodontitis was collected to isolateP. gingivalis. The PRP of four individuals with healthy periodontium and four patients with moderate and severe periodontitis were collected with a specific kit using a two-centrifuge procedure, and then, the antibacterial properties againstP. gingivaliswere tested, through their minimum inhibitory concentration (MIC), adhesion resistance assay, and biofilm susceptibility assay.Results.P. gingivaliswas successfully isolated from the subgingival plaque of the 21st patient. The round, smooth, and black colony appeared in the agar disk after 7–10 days of incubation under anaerobic conditions. Bacterial identification was performed by MALDI-TOF and confirmed by PCR. All PRP samples tested showed the ability to inhibitP. gingivalisgrowth. The MIC value (expressed as fraction of PRP) was 1/2, and PRP preventedP. gingivalisattachment on the disk surface. However, PRP did not have a strong effect on the suppression ofP. gingivalisbiofilm.Conclusion. PRP of individuals with healthy periodontium and chronic periodontitis patients showed antibacterial properties againstP. gingivalis.This material can become an adjunct to periodontal treatment.

scholarly journals Bacteriostatic and Bactericidal Effect of Tigecycline on Leptospira spp.

Antibiotics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 467
Author(s):  
Fabrizio Bertelloni ◽  
Giovanni Cilia ◽  
Filippo Fratini
Keyword(s):  
Antimicrobial Activity ◽  
Urinary Tract ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Bactericidal Effect ◽  
Leptospira Spp ◽  
Tract Disease ◽  
Few Data ◽  
Reference Strains

Tigecycline is a relatively new antimicrobial, belonging to glycylcyclines with antimicrobial activity against a large spectrum of bacteria. Very few data are available on its effect on Leptospira spp., which consist in a bacteriostatic mechanism. The aim of this investigation was to evaluate the bacteriostatic and bactericidal effect of tigecycline on reference Leptospira strains belonging to 16 serovars. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined through the microdilutions method, and tetracycline was used as the control. Results showed that tigecycline had higher MIC and MBC values than tetracycline. Obtained MIC values were between 4 and 32 µg/mL, while MBC values between 16 and >128 µg/mL. Patoc (MIC: 4 µg/mL; MBC: 16 µg/mL) resulted in the most susceptible serovar, while the most resistant were Bataviae (MIC: 32 µg/mL; MBC: 64 µg/mL), Bratislava (MIC: 8 µg/mL; MBC 128 µg/mL), and Tarassovi (MIC: 8 µg/mL; MBC: >128 µg/mL). This is the first investigation focused on the effect of tigecycline against Leptospira spp. reference strains. Since tigecycline is used as a treatment for bacteremia and urinary tract disease, and these symptoms could be linked to Leptospira infection, the possibility of using this antibiotic as a treatment for leptospirosis should be evaluated. Further studies are needed to explore the possibility to use tigecycline for in vivo application against Leptospira.

scholarly journals Preliminary Evaluation of In Vitro Bacteriostatic and Bactericidal Effect of Salt on Leptospira spp.

2020 ◽  
Vol 7 (4) ◽  
pp. 154
Author(s):  
Giovanni Cilia ◽  
Filippo Fratini ◽  
Elena della Buona ◽  
Fabrizio Bertelloni
Keyword(s):  
Marine Mammals ◽  
Inhibitory Concentration ◽  
Chloride Concentration ◽  
Bactericidal Effect ◽  
Preliminary Evaluation ◽  
Environmental Resistance ◽  
Leptospira Spp ◽  
Vitro Effect ◽  
Reference Strains

Environmental resistance is an important factor for understanding the epidemiology of leptospirosis. Recently, new Leptospira hosts were identified, including also marine mammals. Moreover, halotolerant Leptospira strain, isolated from the environment and animals, highlighted the capability of this microorganism to persist in the seawater. The aim of this research was to investigate the bacteriostatic and bactericidal effect of salt on Leptospira strains belonging to 16 different serovars. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were verified through the microdilutions method starting from a 20% sodium chloride concentration. MIC values obtained were between 0.3125% and 10% of salt, while MBC values between 0.625% and >20%. Icterohaemorrhagiae (MIC: 0.3125%; MBC: 0.625%) resulted the most inhibited serovar, while the most resistant was Tarassovi (MIC: 10%; MBC: >20%). Interestingly, trends were reported for Pomona (MIC: 1.25%; MBC: >20%) and Bratislava (MIC: 0.625%; MBC: 20%), highlighting low MIC values but high MBC values. This is the first investigation aimed at the in vitro effect of salt on the growth of Leptospira spp. reference strains.

scholarly journals Surveillance of Antibiotic Resistance of Maltose-Negative Staphylococcus aureus in South African Dairy Herds

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 616
Author(s):  
Joanne Karzis ◽  
Inge-Marié Petzer ◽  
Edward F. Donkin ◽  
Vinny Naidoo ◽  
Eric M.C. Etter
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
South African ◽  
Inhibitory Concentration ◽  
Aureus Strain ◽  
Diffusion Method ◽  
Dairy Herds ◽  
Disk Diffusion Method ◽  
Data Set ◽  
Milk Samples

Antibiotic resistance has been reported since the 1940s in both human and veterinary medicine. Many years of monitoring milk samples in South Africa led to identification of a novel maltose-negative Staphylococcus aureus (S. aureus) strain, which appears to be an emerging pathogen. In this study, the susceptibility of this strain to antibiotics was evaluated over time, during diverse seasons in various provinces and according to somatic cell count (SCC) categories. A data set of 271 maltose-negative S. aureus isolates, from milk samples of 117 dairy herds, was examined using the disk diffusion method, between 2010 and 2017. This study also compared the susceptibility testing of 57 maltose-negative and 57 maltose-positive S. aureus isolated from 38 farms, from three provinces using minimum inhibitory concentration (MIC). The MIC results for the maltose-negative S. aureus isolates showed highest resistance to ampicillin (100%) and penicillin (47.4) and lowest resistance (1.8%) to azithromycin, ciprofloxacin and erythromycin. The maltose-negative S. aureus isolates showed overall significantly increased antibiotic resistance compared to the maltose-positive strains, as well as multidrug resistance. Producers and veterinarians should consider probability of cure of such organisms (seemingly non-chronic) when adapting management and treatment, preventing unnecessary culling.

scholarly journals A Useful Synthesis of 2-Acylamino-1,3,4-oxadiazoles from Acylthiosemicarbazides Using Potassium Iodate and the Discovery of New Antibacterial Compounds

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1490 ◽  
Author(s):  
Tianlei Li ◽  
Gang Wen ◽  
Jishun Li ◽  
Wenxuan Zhang ◽  
Song Wu
Keyword(s):  
Inhibitory Concentration ◽  
Prostate Cancer Cell ◽  
Cancer Cell Line ◽  
Prostate Cancer Cell Line ◽  
Cytotoxic Activities ◽  
Potassium Iodate ◽  
Antibacterial Compounds ◽  
Wide Range ◽  
Antibiotic Compounds ◽  
Mic Minimum Inhibitory Concentration

A useful method for the synthesis of 2-acylamino-1,3,4-oxadiazoles was developed. By using potassium iodate as an oxidant in water at 60 °C, a wide range of 2-acylamino-1,3,4-oxadiazoles were afforded in moderate to excellent yields within two hours. This method could provide a facile shortcut to generate a series of 2-acylamino-1,3,4-oxadiazoles in medicinal chemistry. Interestingly, some highly potent antibiotic compounds were found through this synthetic method, and some of them displayed a significant improvement in activity compared with the corresponding 1,4-diacylthiosemicarbazides. Compound 2n was the most active against Staphylococcus aureus with MIC (minimum inhibitory concentration) of 1.56 mg/mL, and compounds 2m and 2q were the most active against Bacillus subtilis with MIC of 0.78 mg/mL. The preliminary cytotoxic activities of the most potent compounds 2m, 2n, and 2q against the androgen-independent (PC-3) prostate cancer cell line were more than 30 μM (IC50 > 30 μM).

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