scholarly journals Antimicrobial and allelopathic effects of leaves extracts of Myrcia hatschbachii

2021 ◽  
Vol 10 (8) ◽  
pp. e21410817160
Author(s):  
Larissa Junqueira Gatto ◽  
Andressa Veiga ◽  
Natasha Tiemi Fabri Higaki ◽  
Juliane Nadal Dias Swiech ◽  
Elisiane de Bona Sartor ◽  
...  
Keyword(s):  
Crude Extract ◽  
Inhibitory Concentration ◽  
Ethyl Acetate Fraction ◽  
Chloroform Fraction ◽  
Microdilution Method ◽  
Lettuce Seeds ◽  
Biological Potential ◽  
Soxhlet Apparatus ◽  
Broth Microdilution Method ◽  
Germination And Growth

Plants have been seen as alternatives for researching natural antimicrobials and herbicides. The aim of this work was to evaluate the antibacterial, antifungal, and allelopathic properties of leaves extracts of Myrcia hatschbachii. The crude extract and fractions were obtained by Soxhlet apparatus. Antimicrobial activity was determined by the minimum inhibitory concentration (MIC) using the broth microdilution method. The ethyl acetate fraction showed activity against Candida albicans (MIC: 62.5 µg/mL), Staphylococcus aureus (MIC: 500 µg/mL), and Pseudomonas aeruginosa (MIC: 1000 µg/mL). Allelopathic activity evaluated the influence of crude extract and fractions on the germination and growth of Lactuca sativa. The crude extract and the chloroform fraction inhibited the growth of the radicle, while the hexane fraction inhibited the growth of the hypocotyl and radicle of lettuce seeds in all concentrations (100-1000 μg/mL). The biological potential of the species motivates further study of new antimicrobial and bioherbicidal agents.

scholarly journals EXTRACTION OF CRUDE ESSENTIAL FROM SENNA ALATA (POKOK GELENGGANG)

2016 ◽  
Vol 11 (10) ◽  
pp. 3794-3806
Author(s):  
Yee Ching Wong ◽  
Haziqah A. Razak
Keyword(s):  
Traditional Method ◽  
Inhibitory Concentration ◽  
Absolute Ethanol ◽  
Microsporum Gypseum ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Soxhlet Apparatus ◽  
Broth Microdilution Method ◽  
Senna Alata ◽  
Layer Chromatography

Senna alata was one of the herbs plants that can be used to treat the ringworm in traditional method. In this study, the senna alata was scientifically tested to prove the traditional medicinal used. Six forms of extract were extracted by using soxhlet apparatus and continued with the appropriate methods that can extract the chemical compound of anthraquinone. The six forms of extraction included anthraquinone aglycone, anthraquinone glycoside, anthraquinone aglycone from glycoside, anthraquinone from crude absolute ethanol, anthraqunone from crude n-hexane and anthraquinone from crude ethanol 70%. The extraction of six forms of anthraquinone extract as antifungal was observed by tested with two types of fungi; Tricophyton rubrum and Microsporum gypseum. The extraction from crude absolute ethanol and crude n-hexane to inhibit these fungi were compared to determine which type of solvent was the best to use for inhibition. This test was implemented by using well-diffusion and broth microdilution method to determine the minimum inhibitory concentration (MIC). The present of six forms of anthraquinone was examined by using Thin-Layer Chromatography (TLC).

scholarly journals In VitroAntistaphylococcal Effects ofEmbelia schimperiExtracts and Their Component Embelin with Oxacillin and Tetracycline

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Johana Rondevaldova ◽  
Olga Leuner ◽  
Alemtshay Teka ◽  
Ermias Lulekal ◽  
Jaroslav Havlik ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Medicinal Plants ◽  
Bacterial Infections ◽  
Inhibitory Concentration ◽  
Developed Countries ◽  
Positive Interactions ◽  
Fractional Inhibitory Concentration ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method

Bacterial infections are in less-developed countries traditionally treated by remedies prepared from medicinal plants.Embelia schimperi(Vatke) is a plant used as a taenicide or disinfectant in Ethiopia, very often taken mixed with another plant species. In the present study, we examined two extracts prepared from seeds and twigs with leaves ofE. schimperiand its main present secondary metabolite embelin for their antibacterial combinatory effect with oxacillin and tetracycline against sensitive and resistantStaphylococcus aureusstrains. Minimum inhibitory concentrations were determined through the broth microdilution method, whereas the combinatory effect was evaluated through fractional inhibitory concentration sum (ΣFIC) indices. Results show many positive interactions and synergy occurring in embelin and oxacillin combinations against 4 out of 9 strains (ΣFIC 0.203–0.477) and for embelin and tetracycline combination against 3 out of 9 strains (ΣFIC 0.400–0.496). Moreover, the resistance to oxacillin has been overcome in 2 strains and to tetracycline in 3 strains. According to our knowledge, this is the first study showing antimicrobial combinatory effect ofE. schimperias well as of embelin. These findings can be used for the further research targeted on the development of new antistaphylococcal agents.

scholarly journals Antibacterial Activity of 2-(3’,5'-Dibromo-2'-methoxyphenoxy)-3,5-dibromophenol Isolated from Phyllospongia papyracea

2017 ◽  
Vol 12 (4) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Shi Sun ◽  
Corene Canning ◽  
Kuiwu Wang ◽  
Wenjun Zhu ◽  
Fei Yang ◽  
...  
Keyword(s):  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Methanol Extract ◽  
Minimal Bactericidal Concentration ◽  
Antimicrobial Compound ◽  
Highly Active ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Bioassay Guided Fractionation ◽  
And Staphylococcus Aureus

A principal active antimicrobial compound, 2-(3’,5'-dibromo-2'-methoxyphenoxy)-3,5-dibromophenol, was isolated from the methanol extract of Phyllospongia papyracea via bioassay-guided fractionation and isolation. The crude extract and the purified compound were assayed to determine the minimal inhibitory concentration and minimal bactericidal concentration (MBC) using the broth microdilution method. The purified compound was found to be highly active against Bacillus subtilis and Staphylococcus aureus at MIC=1 μg/mL, Campylobacter jejuni at MIC=2 μg/mL, Pseudomonas aeruginosa at MIC=4 μg/mL, and Streptococcus pneumoniae and Listeria monocytogenes at MIC = 8 μg/mL. The activity of this compound was found to be comparable with antibiotics commonly used to control these species of bacteria. The results establish 2-(3’,5'-dibromo-2'-methoxyphenoxy)-3,5-dibromophenol as a potential lead molecule for the development of antibacterial agents.

scholarly journals Curcumin, a Natural Antimicrobial Agent with Strain-Specific Activity

2020 ◽  
Vol 13 (7) ◽  
pp. 153
Author(s):  
Artur Adamczak ◽  
Marcin Ożarowski ◽  
Tomasz M. Karpiński
Keyword(s):  
Inhibitory Concentration ◽  
Specific Activity ◽  
Curcuma Longa ◽  
Antimicrobial Properties ◽  
Antiviral Agent ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Bioactive Substance

Curcumin, a principal bioactive substance of turmeric (Curcuma longa L.), is reported as a strong antioxidant, anti-inflammatory, antibacterial, antifungal, and antiviral agent. However, its antimicrobial properties require further detailed investigations into clinical and multidrug-resistant (MDR) isolates. In this work, we tested curcumin’s efficacy against over 100 strains of pathogens belonging to 19 species. This activity was determined by the broth microdilution method and by calculating the minimum inhibitory concentration (MIC). Our findings confirmed a much greater sensitivity of Gram-positive than Gram-negative bacteria. This study exhibited a significantly larger variation in the curcumin activity than previous works and suggested that numerous clinical strains of widespread pathogens have a poor sensitivity to curcumin. Similarly, the MICs of the MDR types of Staphylococcus aureus, S. haemolyticus, Escherichia coli, and Proteus mirabilis were high (≥2000 µg/mL). However, curcumin was effective against some species and strains: Streptococcus pyogenes (median MIC = 31.25 µg/mL), methicillin-sensitive S. aureus (250 µg/mL), Acinetobacter lwoffii (250 µg/mL), and individual strains of Enterococcus faecalis and Pseudomonas aeruginosa (62.5 µg/mL). The sensitivity of species was not associated with its affiliation to the genus, and it could differ a lot (e.g., S. pyogenes, S. agalactiae and A. lwoffii, A. baumannii). Hence, curcumin can be considered as a promising antibacterial agent, but with a very selective activity.

scholarly journals In Vitro Interaction of Caspofungin Acetate with Voriconazole against Clinical Isolates of Aspergillus spp

2002 ◽  
Vol 46 (9) ◽  
pp. 3039-3041 ◽  
Author(s):  
Sofia Perea ◽  
Gloria Gonzalez ◽  
Annette W. Fothergill ◽  
William R. Kirkpatrick ◽  
Michael G. Rinaldi ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Fractional Inhibitory Concentration ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
In Vitro Interaction ◽  
Vitro Data ◽  
In Vitro Data

ABSTRACT The interaction between caspofungin acetate and voriconazole was studied in vitro by using 48 clinical Aspergillus spp. isolates obtained from patients with invasive aspergillosis. MICs were determined by the NCCLS broth microdilution method. Synergy, defined as a fractional inhibitory concentration (FIC) index of <1, was detected in 87.5% of the interactions; an additive effect, defined as an FIC index of 1.0, was observed in 4.2% of the interactions; and a subadditive effect, defined as an FIC index of 1.0 to 2.0, was found in 8.3% of the interactions. No antagonism was observed. Animal models are required to validate the in vivo significance of these in vitro data presented for the combination of caspofungin and voriconazole.

scholarly journals Validation of a method of broth microdilution for the determination of antibacterial activity of essential oils

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Vanegas David ◽  
Abril-Novillo Andrea ◽  
Khachatryan Aleksandr ◽  
Jerves-Andrade Lourdes ◽  
Peñaherrera Eugenia ◽  
...  
Keyword(s):  
Essential Oils ◽  
Sensitivity And Specificity ◽  
Inhibitory Concentration ◽  
Tween 80 ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Broth Microdilution ◽  
Continuous Contact ◽  
Microdilution Method ◽  
Broth Microdilution Method

Abstract Objective The aim of the present study was to adapt and optimize a broth microdilution method and compare it to the agar dilution method for the evaluation of activity of essential oils from medicinal plants against Gram-negative bacteria. Based on bibliographic research, active and not active oils were selected. The sensitivity and specificity were established as parameters for validation. The comparison between both methods was made using contingency analysis tables, based on the observed frequencies. For both methods, the minimum inhibitory concentration was determined against Escherichiacoli strains, in an essential oil concentration range between 0.03 and 0.48% (v/v). Results A stable emulsion formation was achieved with the addition of Tween 80 and constant agitation, guaranteeing the continuous contact of oil with bacteria (critical step in the microdilution method). The statistical analysis of results obtained with both methods presented a good sensitivity and specificity (100% in both cases), which let us correctly discriminate between active and non-active oils. The values obtained for the minimal inhibitory concentration were independent of the technique used. Finally, the obtained results show that the validated microtechnique allows important diminishment of time and resources for investigations dealing with essential oils or lipophilic extracts evaluation.

scholarly journals Synergistic Antibiofilm Efficacy of Thymol and Piperine in Combination with Three Aminoglycoside Antibiotics against Klebsiella pneumoniae Biofilms

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Borel Bisso Ndezo ◽  
Christian Ramsès Tokam Kuaté ◽  
Jean Paul Dzoyem
Keyword(s):  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Alternative Therapy ◽  
Aminoglycoside Antibiotics ◽  
Antibiofilm Activity ◽  
Promising Alternative ◽  
Microdilution Method ◽  
Fold Reduction ◽  
Broth Microdilution Method

Background. Thymol and piperine are two naturally occurring bioactive compounds with several pharmacological activities. In this study, their antibiofilm potential either alone or in combination with three aminoglycoside antibiotics was evaluated against a biofilm of Klebsiella pneumoniae. Methods. Determination of antimicrobial susceptibility was performed using the broth microdilution method. Biofilm formation was evaluated by the microtiter plate method. Antibiofilm activity was determined using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium-bromide (MTT) assay. The combination studies were performed by the checkerboard microdilution method. Results. The minimum biofilm inhibitory concentration (MBIC) of streptomycin was reduced by 16- to 64-fold when used in combination with thymol, while the MBIC of kanamycin was reduced by 4-fold when combined with piperine. The minimum biofilm eradication concentration (MBEC) values of streptomycin, amikacin, and kanamycin were, respectively, 16- to 128-fold, 4- to 128-fold, and 8- to 256-fold higher than the planktonic minimum inhibitory concentration (MIC). Thymol combined with streptomycin or kanamycin showed synergic effects against the preformed biofilm with 16- to 64-fold reduction in the minimum biofilm eradication concentration values of each antibiotic in combination. Piperine acted also synergically with kanamycin with an 8- to 16-fold reduction in the minimum biofilm eradication concentration values of kanamycin in combination. Conclusion. The association of thymol with antibiotics showed a strong synergistic effect both in the inhibition of biofilm formation and the destruction of the preformed biofilm of K. pneumoniae. This study suggests that a combination of thymol with streptomycin, amikacin, or kanamycin could be a promising alternative therapy to overcome the problem of K. pneumoniae biofilm-associated infections.

scholarly journals Investigation of in vitro activity of colistin and tygecyclin against Stenotrophomonas maltophilia isolates

2021 ◽  
Vol 38 (4) ◽  
pp. 529-532
Author(s):  
Yeliz TANRIVERDİ ÇAYCI ◽  
İlknur BIYIK ◽  
Gonca YILMAZ ◽  
Kemal BİLGİN ◽  
Asuman BİRİNCİ
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Inhibitory Concentration ◽  
Treatment Options ◽  
Opportunistic Pathogen ◽  
Diffusion Method ◽  
Colistin Resistance ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
The Usa

Stenotrophomonas maltophilia has emerged as an important opportunistic pathogen, causing infections whose management is often problematic due to its inherent resistance to many antibiotics. In this study, we aimed to investigate the antimicrobial susceptibility of colistin and tygecyclin as an alternative treatment options for S. maltophilia infections. A total of 122 S. maltophilia isolates were tested. Minimum inhibitory concentration (MIC) values of colistin and tygecycline were determined by broth microdilution method. Susceptibility of TMP/SMX and levofloxacin (LVX) were determined by disc diffusion method and MIC value of ceftazidime (CAZ) was determined by using E-test. Out of 122 S. maltophilia isolates, 5 (4%) of them were resistant to TMP-SXM. MIC range was 0.125- >512 μg/ml and MIC50 64 μg/ml, MIC90 512 μg/ml for colistin. MIC range for tygecyclin was detected as 0.5- >8, MIC50 2 μg/ml and MIC90 8 μg/ml. Tygecyclin resistance was detected as 66.4% according to the EUCAST guideline and 13.1% according to the USA-FDA breakpoints. And colistin resistance was determined as 86.9% according to both guidelines.

scholarly journals Ceftazidime–avibactam and ceftolozane–tazobactam susceptibility of multidrug resistant Pseudomonas aeruginosa strains in Hungary

2020 ◽  
pp. 1-5 ◽  
Author(s):  
Dustin O'Neall ◽  
Emese Juhász ◽  
Ákos Tóth ◽  
Edit Urbán ◽  
Judit Szabó ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inhibitory Concentration ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Test Results ◽  
Diffusion Test ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Gradient Diffusion ◽  
Broth Microdilution Method

Abstract Our objective was to compare the activity ceftazidime-avibactam (C/A) and ceftolozane–tazobactam (C/T) against multidrug (including carbapenem) resistant Pseudomonas aeruginosa clinical isolates collected from six diagnostic centers in Hungary and to reveal the genetic background of their carbapenem resistance. Two hundred and fifty consecutive, non-duplicate, carbapenem-resistant multidrug resistant (MDR) P. aeruginosa isolates were collected in 2017. Minimal inhibitory concentration values of ceftazidime, cefepime, piperacillin/tazobactam, C/A and C/T were determined by broth microdilution method and gradient diffusion test. Carbapenem inactivation method (CIM) test was performed on all isolates. Carbapenemase-encoding blaVIM, blaIMP, blaKPC, blaOXA-48-like and blaNDM genes were identified by multiplex PCR. Of the isolates tested, 33.6& and 32.4& showed resistance to C/A and C/T, respectively. According to the CIM test results, 26& of the isolates were classified as carbapenemase producers. The susceptibility of P. aeruginosa isolates to C/A and C/T without carbapenemase production was 89& and 91&, respectively. Of the CIM-positive isolates, 80& were positive for blaVIM and 11& for blaNDM. The prevalence of Verona integron-encoded metallo-beta-lactamase (VIM)-type carbapenemase was 20.8&. NDM was present in 2.8& of the isolates. Although the rate of carbapenemase-producing P. aeruginosa strains is high, a negative CIM result indicates that either C/A or C/T could be effective even if carbapenem resistance has been observed.

Evaluation of the in vitro interaction of fosfomycin and meropenem against metallo-β-lactamase–producing Pseudomonas aeruginosa using Etest and time-kill assay

2020 ◽  
pp. jim-2020-001573
Author(s):  
Sanjida Jahan ◽  
Heather Davis ◽  
Deborah S Ashcraft ◽  
George A Pankey
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Time Kill ◽  
In Vitro Interaction ◽  
Antimicrobial Combinations

Pseudomonas aeruginosa is a nosocomial pathogen containing various resistance mechanisms. Among them, metallo-β-lactamase (MBL)–producing Pseudomonas are difficult to treat. Fosfomycin is an older antibiotic that has recently seen increased usage due to its activity against a broad spectrum of multidrug-resistant organisms. Our aim was to evaluate the combination of fosfomycin and meropenem against 20 MBL-producing P. aeruginosa (100% meropenem-resistant and 20% fosfomycin-resistant) using both an Etest minimal inhibitory concentration (MIC): MIC method and time-kill assay. MICs for fosfomycin and meropenem were determined by Etest and by broth microdilution method for the latter. The combination demonstrated synergy by Etest in 3/20 (15%) isolates and 5/20 (25%) isolates by time-kill assay. Results from the Etest method and time-kill assay were in agreement for 14/20 (70%) of isolates. No antagonism was found. Comparing both methods, Etest MIC: MIC method may be useful to rapidly evaluate other antimicrobial combinations.

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