scholarly journals In Vitro Antibacterial Activity of Propyl-Propane-Thiosulfinate and Propyl-Propane-Thiosulfonate Derived from Allium spp. against Gram-Negative and Gram-Positive Multidrug-Resistant Bacteria Isolated from Human Samples

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Antonio Sorlozano-Puerto ◽  
Maria Albertuz-Crespo ◽  
Isaac Lopez-Machado ◽  
Juan Jose Ariza-Romero ◽  
Alberto Baños-Arjona ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Bactericidal Activity ◽  
Multidrug Resistant ◽  
Clinical Samples ◽  
Resistant Bacteria ◽  
Moderate Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Multiresistant Bacteria

Background. The aim of this study was to compare the in vitro antibacterial activity of two compounds derived from Alliaceae, PTS (propyl-propane-thiosulfinate), and PTSO (propyl-propane-thiosulfonate), with that of other antibiotics commonly used against bacteria isolated from humans. Materials and Methods. A total of 212 gram-negative bacilli and 267 gram-positive cocci isolated from human clinical samples and resistant to at least one group of antibiotics were selected. In order to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) to various antibiotics as well as PTS and PTSO, all isolates underwent broth microdilution assay. Results. PTS showed moderate activity against Enterobacteriaceae with MIC50 (and MBC50) and MIC90 (and MBC90) values of 256-512 mg/L, while PTSO showed greater activity with MIC50 and MIC90 values of 64-128 mg/L and MBC50 and MBC90 values of 128-512 mg/L. These data show the bactericidal activity of both compounds and indicate that PTSO was more active than PTS against this group of bacteria. Both compounds showed lower activity against P. aeruginosa (MIC50 = 1024 mg/L, MIC90 = 2048 mg/L, MBC50 = 2048 mg/L, and MBC90 = 2048 mg/L, for PTS; MIC50 = 512 mg/L, MIC90 = 1024 mg/L, MBC50 = 512 mg/L, and MBC90 = 2048 mg/L, for PTSO) compared to those obtained in others nonfermenting gram-negative bacilli (MIC50 = 128 mg/L, MIC90 = 512 mg/L, MBC50 = 128 mg/L, and MBC90 = 512 mg/L, for PTS; MIC50 = 64 mg/L, MIC90 = 256 mg/L, MBC50 = 64 mg/L, and MBC90 = 256 mg/L, for PTSO) and also indicate the bactericidal activity of both compounds against these groups of bacteria. Finally, the activity against S. aureus, E. faecalis, and S. agalactiae was higher than that observed against enterobacteria, especially in the case of PTSO (MIC50 = 8 mg/L, MIC90 = 8 mg/L, MBC50 = 32 mg/L, and MBC90 = 64 mg/L, in S. aureus; MIC50 = 4 mg/L, MIC90 = 8 mg/L, MBC50 = 8 mg/L, and MBC90 = 16 mg/L, in E. faecalis and S. agalactiae). Conclusion. PTS and PTSO have a significant broad spectrum antibacterial activity against multiresistant bacteria isolated from human clinical samples. Preliminary results in present work provide basic and useful information for development and potential use of these compounds in the treatment of human infections.

scholarly journals Inhibition of Multidrug-Resistant Gram-Positive and Gram-Negative Bacteria by a Photoactivated Porphyrin

2017 ◽  
Vol 66 (4) ◽  
pp. 533-536 ◽  
Author(s):  
Moreno Bondi ◽  
Anna Mazzini ◽  
Simona de Niederhäusern ◽  
Ramona Iseppi ◽  
Patrizia Messi
Keyword(s):  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
In Vitro Antibacterial Activity

The authors studied the in vitro antibacterial activity of the photo-activated porphyrin meso-tri(N-methyl-pyridyl), mono(N-tetradecyl-pyridyl)porphine (C14) against four multidrug-resistant bacteria: Staphylococcus aureus, Enterococcus faecalis (Gram-positive), Escherichia coli, Pseudomonas aeruginosa (Gram-negative). Using 10 μg/ml of porphyrin and 60 sec irradiation we observed the remarkable susceptibility of S. aureus and E. faecalis to treatment while, under the same conditions, E. coli and P. aeruginosa showed very low susceptibility. In a later stage, suspensions of Gram-negative bacteria were processed with EDTA before photo-activation, obtaining a significant decrease in viable counts. In view of the results, if the combination of low porphyrin concentrations and short irradiation times will be effective in vivo also, this approach could be a possible alternative to antibiotics, in particular against localized infections due to multidrug-resistant microorganisms.

scholarly journals Chromone Derivatives and Other Constituents from Cultures of the Marine Sponge-Associated Fungus Penicillium erubescens KUFA0220 and Their Antibacterial Activity

Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 289 ◽  
Author(s):  
Decha Kumla ◽  
José Pereira ◽  
Tida Dethoup ◽  
Luis Gales ◽  
Joana Freitas-Silva ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Growth Inhibition ◽  
Marine Sponge ◽  
Multidrug Resistant ◽  
Gram Positive ◽  
Gram Negative ◽  
Chromone Derivatives ◽  
Gram Positive Bacteria ◽  
Resistant Strains

A previously unreported chromene derivative, 1-hydroxy-12-methoxycitromycin (1c), and four previously undescribed chromone derivatives, including pyanochromone (3b), spirofuranochromone (4), 7-hydroxy-6-methoxy-4-oxo-3-[(1E)-3-oxobut-1-en-1-yl]-4H-chromene-5-carboxylic acid (5), a pyranochromone dimer (6) were isolated, together with thirteen known compounds: β-sitostenone, ergosterol 5,8-endoperoxide, citromycin (1a), 12-methoxycitromycin (1b), myxotrichin D (1d), 12-methoxycitromycetin (1e), anhydrofulvic acid (2a), myxotrichin C (2b), penialidin D (2c), penialidin F (3a), SPF-3059-30 (7), GKK1032B (8) and secalonic acid A (9), from cultures of the marine sponge- associated fungus Penicillium erubescens KUFA0220. Compounds 1a–e, 2a, 3a, 4, 7–9, were tested for their antibacterial activity against Gram-positive and Gram-negative reference and multidrug-resistant strains isolated from the environment. Only 8 exhibited an in vitro growth inhibition of all Gram-positive bacteria whereas 9 showed growth inhibition of methicillin-resistant Staphyllococus aureus (MRSA). None of the compounds were active against Gram-negative bacteria tested.

scholarly journals Structure of the enterococcal T4SS protein PrgL reveals unique dimerization interface in the VirB8 protein family

2020 ◽  
Author(s):  
Franziska Jäger ◽  
Anaïs Lamy ◽  
Nina Guerini ◽  
Wei-Sheng Sun ◽  
Ronnie P-A Berntsson
Keyword(s):  
Antibiotic Resistance Genes ◽  
Building Blocks ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Secretion Systems ◽  
Multidrug Resistant Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Dimerization Interface

AbstractMultidrug resistant bacteria are one of the most important current threats to public health and a serious problem in hospital acquired infections (HAIs). Most antibiotic resistance genes are acquired via conjugative gene transfer, in a process that is mediated by a protein machinery called the Type 4 Secretion System (T4SS). The core of the T4SS is a multiprotein complex that spans both the cell wall and cellular membrane(s), serving as a channel for macromolecular secretion. Although the majority of multidrug resistant bacteria responsible for HAIs are of Gram-positive origin, with Enterococci being major contributors, mostly Gram-negative T4SSs have been characterized. Here we describe the structure and organisation of PrgL, one of the seven membrane proteins forming the translocation channel of the T4SS encoded by the pCF10 plasmid from Enterococcus faecalis. We present the structure of the C-terminal domain of PrgL, which displays similarity to VirB8 proteins of Gram-negative secretion systems. PrgL forms dimers and higher order oligomers but does not interact strongly with the other T4SS components. In vitro experiments show that the soluble domain alone is enough to drive both dimerization and dodecamerisation, with a dimerization interface that differs from all other known VirB8-like proteins. Our findings provide insight into the molecular building blocks of Gram-positive T4SS, highlighting similarities but also unique features in PrgL compared to other VirB8-like proteins.

scholarly journals The Effect of Charge at the Surface of Silver Nanoparticles on Antimicrobial Activity against Gram-Positive and Gram-Negative Bacteria: A Preliminary Study

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Abbas Abbaszadegan ◽  
Yasamin Ghahramani ◽  
Ahmad Gholami ◽  
Bahram Hemmateenejad ◽  
Samira Dorostkar ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Bactericidal Activity ◽  
Bacterial Species ◽  
Resistant Bacteria ◽  
Proteus Vulgaris ◽  
Surface Charges ◽  
Gram Positive ◽  
Gram Negative ◽  
Positively Charged

The bactericidal efficiency of various positively and negatively charged silver nanoparticles has been extensively evaluated in literature, but there is no report on efficacy of neutrally charged silver nanoparticles. The goal of this study is to evaluate the role of electrical charge at the surface of silver nanoparticles on antibacterial activity against a panel of microorganisms. Three different silver nanoparticles were synthesized by different methods, providing three different electrical surface charges (positive, neutral, and negative). The antibacterial activity of these nanoparticles was tested against gram-positive (i.e.,Staphylococcus aureus,Streptococcus mutans, andStreptococcus pyogenes) and gram-negative (i.e.,Escherichia coliandProteus vulgaris) bacteria. Well diffusion and micro-dilution tests were used to evaluate the bactericidal activity of the nanoparticles. According to the obtained results, the positively-charged silver nanoparticles showed the highest bactericidal activity against all microorganisms tested. The negatively charged silver nanoparticles had the least and the neutral nanoparticles had intermediate antibacterial activity. The most resistant bacteria wereProteus vulgaris. We found that the surface charge of the silver nanoparticles was a significant factor affecting bactericidal activity on these surfaces. Although the positively charged nanoparticles showed the highest level of effectiveness against the organisms tested, the neutrally charged particles were also potent against most bacterial species.

scholarly journals Phytochemical Screening and In Vitro Antibacterial Activities of Leaf Extract Acacia etbaica Schweinf Against Multidrug Resistant Enterobacteriaceae Human Pathogens

2020 ◽  
Vol 11 (3) ◽  
pp. 4857-4865
Author(s):  
Tekleweyni Tadege ◽  
Kidu Hintsa ◽  
Tesfay Weletnsae ◽  
Gopalakrishnan V K ◽  
Muthulingam M ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Leaf Extract ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Phytochemical Screening ◽  
Leaf Extracts ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

Acacia etbaica Schweinf belongs to the family Fabaceae widely distributed in Africa and various parts of this plant such as bark, leaves, flowers and roots are widely used as a folk medicine for curing of various ailments.This study was aimed to screen the phytoconstituents and evaluate the antibacterial activity of leaf extract of A. etbaica against selected multidrug resistant Enterobacteriaceae family. Leaves of A. etbaica were extracted with petroleum ether, chloroform, acetone, and ethanol by sequential soxhlet extraction. Phytochemical screening of organic leaf extract of A.etbaica was carried out for the detection of phytoconstituents accountable for antibacterial activity. In vitro antibacterial activities of A.etbaica leaf extracts against selected Enterobacteriaceae family gram‑positive bacteria such as (B.subtilis, E.faecalis,S.aureus)and gram-negative (E. coli, K. pneumonia, V. cholera) were evaluated by agar well diffusion. The antibacterial potential of acetone and ethanol leaf extracts of A.etbaica were determined by 96 well plate broth dilution assay. Among the tested organic leaf extracts, both acetone and ethanolic leaf extract of A.etbaica showed a potentially broad spectrum of in vitro antibacterial activity against tested multiple drug resistant Enterobacteriaceae family gram-positive pathogens such as B.subtilis, E. faecalis , and S.aureus and gram-negative bacterial strains E. coli, K. Pneumonia and V. Cholera with significant MIC values. The significant antibacterial activity of both acetone and ethanolic leaf extracts of A.etbaica was due to the subsistence of secondary metabolites phytoconstituents such as flavonoids and phenolic compounds.

Design, synthesis and antibacterial evaluation of ocotillol derivatives with polycyclic nitrogen-containing groups

2021 ◽  
Author(s):  
Yucheng Cao ◽  
Kaiyi Wang ◽  
Jiali Wang ◽  
Haoran Cheng ◽  
Mengxin Ma ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Multidrug Resistant ◽  
Inhibitory Effect ◽  
Resistant Bacteria ◽  
Design Synthesis ◽  
In Vitro Antibacterial Activity ◽  
Strong Inhibitory Effect ◽  
Hospital Acquired ◽  
Derivatives Of

Aim: With the increasing abuse of antibacterial drugs, multidrug-resistant bacteria have become a burden on human health and the healthcare system. To find alternative compounds effective against hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA), novel derivatives of ocotillol were synthesized. Methods & Results: Ocotillol derivatives with polycyclic nitrogen-containing groups were synthesized and evaluated for in vitro antibacterial activity. Compounds 36–39 exhibited potent antibacterial activity against hospital-acquired MRSA, with MIC = 8–64 μg/ml. Additionally, a combination of compound 37 and the commercially available antibiotic kanamycin showed synergistic inhibitory effects, with a fractional inhibitory concentration index of ≤0.375. Conclusion: Compound 37 has a strong inhibitory effect, and this derivative has potential for use as a pharmacological tool to explore antibacterial mechanisms.

scholarly journals Sarconesin II, a New Antimicrobial Peptide Isolated from Sarconesiopsis magellanica Excretions and Secretions

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2077 ◽  
Author(s):  
Andrea Díaz-Roa ◽  
Abraham Espinoza-Culupú ◽  
Orlando Torres-García ◽  
Monamaris M. Borges ◽  
Ivan N. Avino ◽  
...  
Keyword(s):  
Micrococcus Luteus ◽  
Multidrug Resistant ◽  
Peptide Sequence ◽  
Resistant Bacteria ◽  
Gram Positive ◽  
Antimicrobial Drugs ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Conserved Domain ◽  
Health Institutions

Antibiotic resistance is at dangerous levels and increasing worldwide. The search for new antimicrobial drugs to counteract this problem is a priority for health institutions and organizations, both globally and in individual countries. Sarconesiopsis magellanica blowfly larval excretions and secretions (ES) are an important source for isolating antimicrobial peptides (AMPs). This study aims to identify and characterize a new S. magellanica AMP. RP-HPLC was used to fractionate ES, using C18 columns, and their antimicrobial activity was evaluated. The peptide sequence of the fraction collected at 43.7 min was determined by mass spectrometry (MS). Fluorescence and electronic microscopy were used to evaluate the mechanism of action. Toxicity was tested on HeLa cells and human erythrocytes; physicochemical properties were evaluated. The molecule in the ES was characterized as sarconesin II and it showed activity against Gram-negative (Escherichia coli MG1655, Pseudomonas aeruginosa ATCC 27853, P. aeruginosa PA14) and Gram-positive (Staphylococcus aureus ATCC 29213, Micrococcus luteus A270) bacteria. The lowest minimum inhibitory concentration obtained was 1.9 μM for M. luteus A270; the AMP had no toxicity in any cells tested here and its action in bacterial membrane and DNA was confirmed. Sarconesin II was documented as a conserved domain of the ATP synthase protein belonging to the Fli-1 superfamily. The data reported here indicated that peptides could be alternative therapeutic candidates for use in infections against Gram-negative and Gram-positive bacteria and eventually as a new resource of compounds for combating multidrug-resistant bacteria.

scholarly journals Cyathea gigantea (Cyatheaceae) as an antimicrobial agent against multidrug resistant organisms

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Kathakali Nath ◽  
Anupam Das Talukdar ◽  
Mrinal Kanti Bhattacharya ◽  
Deepshikha Bhowmik ◽  
Shiela Chetri ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Property ◽  
Treatment Options ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Synergistic Activity ◽  
Gram Positive ◽  
Traditional Use ◽  
Gram Negative ◽  
Multidrug Resistant Organisms

Abstract Background Rapid emergence of multidrug resistant (MDR) organisms in hospital and community settings often result into treatment failure, thus leading the clinicians with fewer treatment options. Cyathea gigantea, an ethnomedicinally important fern used in cuts and wound infections. So, if this medicinal plant is used in treating the MDR infections then it might bring certain relief in future treatment options. Methods Antibacterial activity of C. gigantea against MDR bacteria was assed using well diffusion and broth microdilution methods to determine the diameters of growth inhibition zones, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Synergistic activity was also determined with the conventional antibiotics by disc diffusion method followed by FIC index of each of the tested antibiotic was calculated. The active extract was then subjected to fractionation by column chromatography and antibacterial activity was done with each of the collected fractions. Results Crude extract of C. gigantea was found to be active against all the tested organisms. The MIC was 200 μg/ml against Gram-positive i.e., Staphylococcus aureus ATCC 25923 and 400 μg/ml against Gram-negative i.e., Escherichia coli ATCC 25922 and Pseudomonas aeruginosa PAO1, while the MBC was 400 μg/ml in case of Gram-positive and 800 μg/ml for Gram-negative. The synergistic activity revealed that the plant extract increased the antibacterial property of the studied antibiotics and the FIC index showed that significant synergistic activity was shown by ciprofloxacin followed by tetracycline, ampicillin and oxacillin. Antibacterial activity with the fractionated extract showed that the FR II, FR III and FR IV were active against both Gram-positive and Gram-negative bacteria, whereas FR I, FR V and FR VI did not show antibacterial property against any of the tested bacteria. Conclusions Extracts of C. gigantea was found active against both selected Gram-positive and Gram-negative organisms and thus offers the scientific basis for the traditional use of the fern. The present study also provides the basis for future study to validate the possible use against multidrug resistant organisms.

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