scholarly journals In Vitro Sensitivity Research Concerning Some Microorganisms at Hydroxyquinoline and Cupric Derivatives Deposited onto Hydroxyapatite

2016 ◽  
Vol 73 (2) ◽  
pp. 339
Author(s):  
Sorin Rapuntean ◽  
Alexandru Pop ◽  
Vasile Miclaus ◽  
Corina Garbo ◽  
Flore Chirila ◽  
...  
Keyword(s):  
Chemical Engineering ◽  
Antimicrobial Effect ◽  
Inhibitory Effect ◽  
Candida Spp ◽  
Gram Positive ◽  
In Vitro Susceptibility ◽  
Beneficial Effects ◽  
Diffusion Technique ◽  
Bacillus Spp

ABSTRACT Introduction: The preparations based on hydroxyquinoline, in various combinations, are used in medicine, being shown to have an inhibitory effect against bacteria, molds, fungi, parasites, and viruses, but also having other beneficial effects mentioned in other medical conditions (anti-cancer, anti-degenerative, anti-inflammatory). Aims: In vitro susceptibility testing of microorganisms: bacteria (Gram positive and Gram negative), yeast (Candida spp.,) and unicellular algae (Prototheca spp.) at the preparations based on hydroxyquinoline (HQ) and its cupric derivatives deposited on hydroxyapatite (HAP). Materials and methods: There were tested microbial strains of the following genera: Escherichia, Staphylococcus, Micrococcus, Bacillus, Candida, and Prototheca. The tested products (developed in the Laboratory for Nanobiomaterials Synthesis, Center of Physical Chemistry, Faculty of Chemistry and Chemical Engineering, UBB Cluj-Napoca) were developed in three versions: 1) HQ–Cu2+–HAP1; 2) HQ–Cu2+–HAP2; and 3) NHQ–Cu2+–HAP2, where NHQ stands for nitro hydroxyquinoline. Determination of the inhibitory effect was conducted by diffusion technique in nutrient agar, according to CLSI 2013 standards, with necessary adaptations for testing of products made in the form of suspensions. Results: Following interpretation, it was found that the inhibition zones, arising from the antimicrobial effect of the tested products showed variability in size, depending on the test product and the microbial strain: Escherichia coli (8-10 mm), Staphylococcus sp. (17.6 - 23.2 mm), Micrococcus spp. (24.4 - 27.6 mm), Bacillus spp. (14.0 - 16.0 mm), Candida spp. (20.4 - 25.2 mm), Prototheca spp. (20.8 - 30.0 mm). From the three tested products, the best efficacy was found at the product no. 3 (NHQ – Cu2+ – HAP2), followed by no. 1 (HQ– Cu2+–HAP1) and no. 2 (HQ–Cu2+–HAP2). Conclusions: The inhibitory effect was bactericidal, manifested more intensively against Gram-positive bacteria, yeasts, and prototheca. Such products, prepared in the form of suspensions, may have practical application in the prevention and treatment of skin or hooves disorders. No resistance phenomena are recorded. Keywords: copper, hydroxyapatite, hydroxyquinoline, microorganisms, sensitivity.

scholarly journals Biocontrol of Chickpea Fusarium Wilt by Bacillus Spp. Rhizobacteria

2013 ◽  
Vol 53 (2) ◽  
pp. 177-183 ◽  
Author(s):  
Souad Zaim ◽  
Lakhdar Belabid ◽  
Miloud Bellahcene
Keyword(s):  
Disease Control ◽  
Fusarium Wilt ◽  
Mycelial Growth ◽  
Field Trials ◽  
Inhibitory Effect ◽  
In Vitro Assays ◽  
Beneficial Effects ◽  
Volatile Metabolites ◽  
Bacillus Spp

Abstract Among 131 rhizobacteria isolates, 29 potentially antagonistic strains were screened in in vitro assays. The five antagonistic Bacillus spp. Rb29, Rb6, Rb12, Rb4, and Rb15 showed the most inhibitory effect against FOC1 (from 25.63 to 71.11%), mycelial growth, and FOC2 (from 28.43 to 60.65%) in vitro. Results also revealed that production of volatile metabolite, components and inhibition of the test pathogen by volatile metabolites varied among different antagonistic rhizobacteria. Isolates Rb29, Rb6, Rb12, Rb4, and Rb15 produced more volatile metabolites which inhibited mycelial FOC growth by 40%. Chickpea Fusarium wilt severity caused by FOC1 was reduced from 60 to 99% in the susceptible cultivar ILC 482 treated with antagonistic Bacillus spp. (Rb29, Rb6, Rb12, Rb4, and Rb15) in pot assays and by 98, 81, 68, 64, 57.20%, respectively, in the field trials. As for their beneficial effects on disease control, the results revealed that Bacillus spp. may improve plant growth and disease control.

Phenolic Acids Exert Anticholinesterase and Cognition-Improving Effects

2018 ◽  
Vol 15 (6) ◽  
pp. 531-543 ◽  
Author(s):  
Dominik Szwajgier ◽  
Ewa Baranowska-Wojcik ◽  
Kamila Borowiec
Keyword(s):  
Phenolic Acids ◽  
Ex Vivo ◽  
Amyloid Β ◽  
Inhibitory Effect ◽  
In Vivo Studies ◽  
Amyloid Β Peptide ◽  
Beneficial Effects ◽  
Aβ Fibrils

Numerous authors have provided evidence regarding the beneficial effects of phenolic acids and their derivatives against Alzheimer's disease (AD). In this review, the role of phenolic acids as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) is discussed, including the structure-activity relationship. In addition, the inhibitory effect of phenolic acids on the formation of amyloid β-peptide (Aβ) fibrils is presented. We also cover the in vitro, ex vivo, and in vivo studies concerning the prevention and treatment of the cognitive enhancement.

scholarly journals In Vitro Effect of Photodynamic Therapy with Different Lights and Combined or Uncombined with Chlorhexidine on Candida spp.

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1176
Author(s):  
Vanesa Pérez-Laguna ◽  
Yolanda Barrena-López ◽  
Yolanda Gilaberte ◽  
Antonio Rezusta
Keyword(s):  
Photodynamic Therapy ◽  
Light Emitting Diode ◽  
Antimicrobial Effect ◽  
Photodynamic Treatment ◽  
Candida Spp ◽  
Promising Alternative ◽  
Light Emitting ◽  
Colony Forming Units ◽  
Vitro Effect

Candidiasis is very common and complicated to treat in some cases due to increased resistance to antifungals. Antimicrobial photodynamic therapy (aPDT) is a promising alternative treatment. It is based on the principle that light of a specific wavelength activates a photosensitizer molecule resulting in the generation of reactive oxygen species that are able to kill pathogens. The aim here is the in vitro photoinactivation of three strains of Candida spp., Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258, using aPDT with different sources of irradiation and the photosensitizer methylene blue (MB), alone or in combination with chlorhexidine (CHX). Irradiation was carried out at a fluence of 18 J/cm2 with a light-emitting diode (LED) lamp emitting in red (625 nm) or a white metal halide lamp (WMH) that emits at broad-spectrum white light (420–700 nm). After the photodynamic treatment, the antimicrobial effect is evaluated by counting colony forming units (CFU). MB-aPDT produces a 6 log10 reduction in the number of CFU/100 μL of Candida spp., and the combination with CHX enhances the effect of photoinactivation (effect achieved with lower concentration of MB). Both lamps have similar efficiencies, but the WMH lamp is slightly more efficient. This work opens the doors to a possible clinical application of the combination for resistant or persistent forms of Candida infections.

scholarly journals Antifungal and Antibacterial Metabolites from a French Poplar Type Propolis

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Séverine Boisard ◽  
Anne-Marie Le Ray ◽  
Anne Landreau ◽  
Marie Kempf ◽  
Viviane Cassisa ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Antimicrobial Effect ◽  
Antibacterial Activities ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Gram Positive ◽  
Weak Activity ◽  
Agar Dilution

During this study, thein vitroantifungal and antibacterial activities of different extracts (aqueous and organic) obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains:Candida albicans, C. glabrata, andAspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains includingStaphylococcus aureus. Organic extracts showed a significant antifungal activity againstC. albicansandC. glabrata(MIC80between 16 and 31 µg/mL) but only a weak activity towardsA. fumigatus(MIC80= 250 µg/mL). DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially againstS. aureus(SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC10030–97 µg/mL). A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.

Meropenem: A New Carbapenem Antimicrobial

1994 ◽  
Vol 28 (9) ◽  
pp. 1045-1054 ◽  
Author(s):  
Randy D. Pryka ◽  
George M. Haig
Keyword(s):  
Clinical Trials ◽  
English Language ◽  
Antimicrobial Agents ◽  
Pharmacokinetic Analysis ◽  
Upper Respiratory Tract ◽  
Gram Positive ◽  
Scientific Publications ◽  
In Vitro Susceptibility ◽  
Study Selection

OBJECTIVE: To describe and then compare an investigational carbapenem antibiotic, meropenem, with the only currently available antibiotic in this class, imipenem/cilastatin. DATA IDENTIFICATION: An English language search using MEDLINE (1988–1993); Abstracts of the 31st Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), 1991; and Abstracts of the 32nd ICAAC, 1992. STUDY SELECTION: All current scientific publications were reviewed for study design and quality. Emphasis was placed on susceptibility and pharmacokinetic analysis. Phase 3 clinical trials are now being completed and have only been published in abstract form. Hence, conclusions derived regarding efficacy were tempered. RESULTS: Meropenem is active against a broad spectrum of gram-positive and -negative pathogens including beta-lactamase producers. Meropenem appears to be two- to fourfold less active than imipenem against gram-positive organisms. Meropenem is two- to fivefold more active against enterobacteriaceae. The two compounds appear to be equally active against Pseudomonas aeruginosa. Pharmacokinetic disposition is also similar for imipenem and meropenem. Meropenem may exhibit greater tissue penetration. Meropenem is not labile to renal hydrolysis and can be administered without a competitive antagonist of dihydropeptidase, such as cilastatin. In clinical trials, meropenem appears to be as safe and effective as imipenem/cilastatin or ceftazidime in the treatment of infections involving soft tissue, urinary tract, upper respiratory tract, abdominal processes, and febrile neutropenic episodes. CONCLUSIONS: Meropenem is comparable to imipenem in terms of in vitro susceptibility pattern and pharmacokinetic disposition. Overall, meropenem seems to offer promise as the second of the carbapenem class of antibiotics. Clinical data are preliminary, and further data are needed.

In vitro Susceptibility to Everninomycin of Gram-Positive Nosocomial Pathogens Isolated from Intensive Care Units in Germany

Chemotherapy ◽  
2000 ◽  
Vol 47 (1) ◽  
pp. 15-18 ◽  
Author(s):  
Andrea Kropec ◽  
Andrea Kropec ◽  
Uwe Frank ◽  
Uwe Frank ◽  
Daniel Jonas ◽  
...  
Keyword(s):  
Intensive Care ◽  
Intensive Care Units ◽  
Gram Positive ◽  
In Vitro Susceptibility ◽  
Nosocomial Pathogens

Evaluation of in vitro susceptibility of Gram-positive pathogens from a tertiary care hospital in Singapore to a novel oxazolidinone, tedizolid, by a gradient diffusion method and broth microdilution

2018 ◽  
Vol 72 (2) ◽  
pp. 181-184
Author(s):  
Saugata Choudhury ◽  
Lee Kar Mun ◽  
Esme Ng Chu Xuan ◽  
Lee Shin Jia ◽  
Shawn Vasoo ◽  
...  
Keyword(s):  
Tertiary Care ◽  
Bloodstream Infections ◽  
Diffusion Method ◽  
Care Hospital ◽  
Broth Microdilution ◽  
Coagulase Negative Staphylococci ◽  
Gram Positive ◽  
In Vitro Susceptibility ◽  
Gradient Diffusion

We compared the in vitro antimicrobial activities of tedizolid and linezolid on the Sensititre broth microdilution system for Gram-positive cocci isolates (n=146) from skin and skin structure infections and bloodstream infections, bronchoalveolar lavage and sputum. These pathogens included 40 methicillin-resistant Staphylococcus aureus, 38 coagulase-negative staphylococci, 20 Enterococcus faecalis and 48 beta-haemolytic Streptococcus spp. Susceptibility was simultaneously determined for 48 vanA vancomycin-resistant enterococci isolates 2013–2016 from rectal swabs (23 E. faecalis and 25 E. faecium, of which 4 were linezolid-non-susceptible). MIC90s for tedizolid were fourfold to eightfold lower than linezolid on the Sensititre and ranged from 0.12 to 0.5 µg/mL for the different pathogen groups. All isolates were susceptible to tedizolid except two vanA E. faecium strains (MICs of 1 and 2 µg/mL, respectively). Categorical and essential agreement for tedizolid were 99.48% and 92%, respectively, between Liofilchem gradient diffusion and Sensititre methods. Overall, the drug exhibited excellent activity against the surveyed Gram-positive pathogens.

scholarly journals 686. Evaluation of Contezolid Activity to Anaerobic and Gram-positive-cocci Isolates from a Phase 3 Acute Bacterial Skin and Skin Structure Infection Clinical Trial (MRX-I-06)

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S312-S312
Author(s):  
Yang Yang ◽  
Demei Zhu
Keyword(s):  
Dilution Method ◽  
Phase 3 ◽  
Gram Positive ◽  
In Vitro Susceptibility ◽  
Skin Structure ◽  
Prevotella Bivia ◽  
In Vitro Antibacterial Activity ◽  
Agar Dilution ◽  
Leuconostoc Lactis

Abstract Background Contezolid (MRX-I) is an oxazolidinone in development for the treatment of acute bacterial skin and skin structure infections (ABSSSIs). In this study, in vitro susceptibility (S) for Contezolid and comparator agents for Gram-positive (GP) and anaerobic isolates from Phase 3 ABSSSI clinical trials were determined. Methods 313 isolates were collected from 65 participated sites and sent to a central laboratory for MIC testing. Clinical isolates included 34 anaerobes (15 Finegoldia magna, 8 Actinomyces spp., 4 Prevotella spp., 3 Propionibacterium avidum, 2 Peptostreptococcus spp., 1 Veillonella spp. and 1 Bacteroides fragilis), 187 S. aureus (59.7%). 12 S. pyogenes, 5 Enterococcus, and 75 other Gram-positive organisms. Broth micro-dilution method was used to determine the MIC of contezolid, linezolid, and other comparators to facultative isolates. Agar dilution was carried out for the anaerobes. Results For both 33 MRSA and 154 MSSA MIC50/90 values of contezolid and linezolid were 2 mg/L. One E. faecalis showed decreased susceptibility to oxazolidinones (both MIC = 4). 1 mg/L contezolid and linezolid could inhibit 12 S. pyogenes. 2 mg/L contezolid and linezolid could inhibit 15 Finegoldia magna. 0.5 mg/L contezolid and linezolid could inhibit 8 Actinomyces spp. To one Bacteroides fragili, two Prevotella bivia and one Leuconostoc lactis (Intrinsic resistant to vancomycin) the MIC of contezolid were 4 or 8 mg/L. In general, Contezolid had lower or equal MIC50/90 values against both GP and ANA species compared with linezolid for all organisms. Conclusion Contezolid demonstrated potent in vitro antibacterial activity against Gram-positive and anaerobic isolates tested. These data suggest that contezolid might be a beneficial supplement to the arena against MDR Gram-positive infection. Disclosures All authors: No reported disclosures.

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