scholarly journals Antibacterial Triterpenoids from the Bark of Sonneratia alba (Lythraceae)

2015 ◽  
Vol 10 (2) ◽  
pp. 1934578X1501000
Author(s):  
Harizon ◽  
Betry Pujiastuti ◽  
Dikdik Kurnia ◽  
Dadan Sumiarsa ◽  
Yoshihito Shiono ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Mass Spectrometric ◽  
Broth Microdilution ◽  
Mass Spectrometric Data ◽  
Spectrometric Data ◽  
Gram Positive Bacteria ◽  
Microdilution Method ◽  
Sonneratia Alba ◽  
Broth Microdilution Method

The new lupane-type triterpenoid, 3β-hydroxy-lup-9(11), 12-diene, 28-oic acid (1), along with two known lupane-type triterpenoids, lupeol (2) and lupan-3p-ol (3), were isolated from the bark of Sonnetaria alba. The structure of the new compound was elucidated on the basis of spectroscopic and mass spectrometric data analysis. Using the broth microdilution method, all compounds exhibited antibacterial activity against the Gram-positive bacteria Staphylococcus aureus ATCC 6538 and Streptococcus mutans ATCC 25175, with minimum inhibitory concentrations ranging from 15-33 to 35-55 ng/mL, respectively.

scholarly journals Synergy between Essential Oils of Calamintha Species (Lamiaceae) and Antibiotics

2018 ◽  
Vol 13 (3) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Marina Milenković ◽  
Jelena Stošović ◽  
Violeta Slavkovska
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Essential Oil ◽  
Essential Oils ◽  
Broth Microdilution ◽  
Bacterial Strains ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
The Subject

The subject of the study was the investigation of the chemical composition and antimicrobial activity of the essential oils (EOs) isolated from Calamintha sylvatica, C. vardarensis, C. nepeta and C. glandulosa, as well as their antibacterial activity in combination with antibiotics. The quantitative and qualitative analysis of EOs was performed using the GC/FID and GC/MS methods. The antimicrobial activity of EOs against six standard bacterial strains and one strain of yeast was tested using the broth microdilution method, while the antimicrobial activity of a combination of essential oils and gentamicin/ciprofloxacin was tested by the checkerboard method. The dominant components (> 10%) of the essential oils were: cis-piperitone epoxide and menthone ( C. sylvatica), pulegone and menthone ( C. vardarensis), pulegone and piperitenone ( C. nepeta), pulegone, piperitenone, menthone and piperitone ( C. glandulosa). EOs did not exhibit significant antimicrobial activity except the essential oil of C. vardarensis which was selectively active against Staphylococcus aureus (MIC - 21.25 μg/mL). The overall effect of essential oil-antibiotic combinations varied from synergistic (FICI ≤ 0.5) to antagonistic (FICI ≥ 2) depending on the bacterial strain tested.

scholarly journals Combination Therapy of Sophoraflavanone B against MRSA:In VitroSynergy Testing

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Su-Hyun Mun ◽  
Ok-Hwa Kang ◽  
Dae-Ki Joung ◽  
Sung-Bae Kim ◽  
Yun-Soo Seo ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Multidrug Resistant ◽  
Antibacterial Drug ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Kill Curve ◽  
Time Kill

Sophoraflavanone B (SPF-B), a known prenylated flavonoid, was isolated from the roots ofDesmodium caudatum. The aim of this study was to determine the antimicrobial synergism of SPF-B combined with antibiotics against methicillin-resistantStaphylococcus aureus(MRSA). MRSA, a multidrug-resistant pathogen, causes both hospital- and community-acquired infections worldwide. The antimicrobial activity of SPF-B was assessed by the broth microdilution method, checkerboard dilution test, and time-kill curve assay. The MIC of SPF-B for 7 strains ofS. aureusranges from 15.6 to 31.25 μg/mL determined. In the checkerboard method, the combinations of SPF-B with antibiotics had a synergistic effect; SPF-B markedly reduced the MICs of theβ-lactam antibiotics: ampicillin (AMP) and oxacillin (OXI); aminoglycosides gentamicin (GET); quinolones ciprofloxacin (CIP) and norfloxacin (NOR) against MRSA. The time-kill curves assay showed that a combined SPF-B and selected antibiotics treatment reduced the bacterial counts below the lowest detectable limit after 24 h. These data suggest that the antibacterial activity of SPF-B against MRSA can be effectively increased through its combination with three groups of antibiotics (β-lactams, aminoglycosides, and quinolones). Our research can be a valuable and significant source for the development of a new antibacterial drug with low MRSA resistance.

scholarly journals Evaluation of the Antibacterial Activity and Efflux Pump Reversal of Thymol and Carvacrol against Staphylococcus aureus and Their Toxicity in Drosophila melanogaster

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2103 ◽  
Author(s):  
Zildene de Sousa Silveira ◽  
Nair Silva Macêdo ◽  
Joycy Francely Sampaio dos Santos ◽  
Thiago Sampaio de Freitas ◽  
Cristina Rodrigues dos Santos Barbosa ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Drosophila Melanogaster ◽  
Inhibitory Concentration ◽  
Efflux Pump ◽  
Antibacterial Activities ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Efflux Pump Inhibition ◽  
Broth Microdilution Method

The antibacterial activity and efflux pump reversal of thymol and carvacrol were investigated against the Staphylococcus aureus IS-58 strain in this study, as well as their toxicity against Drosophila melanogaster. The minimum inhibitory concentration (MIC) was determined using the broth microdilution method, while efflux pump inhibition was assessed by reduction of the antibiotic and ethidium bromide (EtBr) MICs. D. melanogaster toxicity was tested using the fumigation method. Both thymol and carvacrol presented antibacterial activities with MICs of 72 and 256 µg/mL, respectively. The association between thymol and tetracycline demonstrated synergism, while the association between carvacrol and tetracycline presented antagonism. The compound and EtBr combinations did not differ from controls. Thymol and carvacrol toxicity against D. melanogaster were evidenced with EC50 values of 17.96 and 16.97 µg/mL, respectively, with 48 h of exposure. In conclusion, the compounds presented promising antibacterial activity against the tested strain, although no efficacy was observed in terms of efflux pump inhibition.

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 the Essential Oil of Heracleum Sibiricum

2013 ◽  
Vol 8 (9) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Dragoljub L. Miladinović ◽  
Budimir S. Ilić ◽  
Tatjana M. Mihajilov-Krstev ◽  
Dejan M. Nikolić ◽  
Olga G. Cvetković ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Essential Oil ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
Gram Positive Bacteria ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Major Chemical ◽  
Total Oil ◽  
Chemical Class

The composition and antimicrobial activity of the essential oil of Heracleum sibiricum L. (Apiaceae) was studied. The aerial part of plant was hydro-distilled and chemical composition of the essential oil was analyzed by GC and GC-MS. Forty-six compounds, corresponding to 95.12% of the total oil, were identified. Esters represented the major chemical class (69.55%) while the main constituents were octyl butanoate (36.82%), hexyl butanoate (16.08%), 1-octanol (13.62%) and octyl hexanoate (8.10%). Antibacterial activity of the essential oil and reference antibiotics against nine bacterial strains was tested by the broth microdilution method. The results of the bioassays showed that essential oil had slight antimicrobial activities against all tested microorganisms (MIC and MBC values were in the range of 2431.2 to 9724.8 μg/mL). Reference antibiotics were active in concentrations between 0.5 and 16.0 μg/mL. The results confirm that Gram-positive bacteria were more susceptible to the essential oil of H. sibiricum, in comparison with Gram-negative bacteria.

scholarly journals In vitro activity of the trinem sanfetrinem (GV104326) against gram-positive organisms.

1996 ◽  
Vol 40 (9) ◽  
pp. 2142-2146 ◽  
Author(s):  
K V Singh ◽  
T M Coque ◽  
B E Murray
Keyword(s):  
Staphylococcus Aureus ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Gentamicin Resistance ◽  
High Level

The in vitro activity of the trinem sanfetrinem (formerly GV104326) (GV) was compared with that of vancomycin, ampicillin, and/or nafcillin against 287 gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and multiresistant enterococci, by the agar and microbroth dilution methods. GV demonstrated 2 to 16 times more activity than ampicillin and nafcillin against the majority of these organisms. The MIC range of GV was 16 to 64 micrograms/ml for 19 Enterococcus faecium strains that were highly resistant to ampicillin (ampicillin MIC range, 64 to 512 micrograms/ml) and vancomycin resistant and 0.25 to 32 micrograms/ml for resistant Rhodococcus spp. Similar activities (+/-1 dilution) were observed by either the agar or the broth microdilution method. GV demonstrated bactericidal activity against a beta-lactamase-producing Enterococcus faecalis strain and against two methicillin-susceptible Staphylococcus aureus strains in 10(5)-CFU/ml inocula. Synergy between GV and gentamicin was observed against an E. faecalis strain that lacked high-level gentamicin resistance. The activity of GV suggests this compound warrants further study.

scholarly journals Antibacterial Activity of Antibiotic-Impregnated Bone Cement Based Coatings Against Microorganisms with Different Antibiotic Resistance Levels

2018 ◽  
Vol 24 (4) ◽  
pp. 105-110
Author(s):  
D. V. Tapalski ◽  
P. A. Volotovski ◽  
A. I. Kozlova ◽  
A. Sitnik
Keyword(s):  
Antibacterial Activity ◽  
Bone Cement ◽  
Antibiotic Activity ◽  
Broth Microdilution ◽  
Antibiotic Resistant ◽  
Microdilution Method ◽  
Bactericidal Properties ◽  
Broth Microdilution Method ◽  
Marked Activity ◽  
Agar Method

Purpose — to evaluate the presence and duration of antibiotic activity of antibiotic-impregnated bone cement based coatings samples against antibiotic-sensitive and antibiotic-resistant microorganisms.Material and Methods. Bone cement based coatings impregnated with antibiotics (gentamycin, vancomycin, colistin, meropenem, fosfomycin) are formed on titanium (Ti) plates. A plate rinse was carried out; antibiotic concentrations in the rinsed solutions were estimated by a serial broth microdilution method. Antibacterial activity of the control and rinsed samples against the antibiotic-sensitive and multiple-antibiotic-resistant Staphylococcus aureus and Pseudomonas aeruginosa strains was estimated by a bilayer agar method.Results. The meropenem and fosfomycin concentrations in the rinsed solutions obtained at a one-fold (16 μg/ml for both antibiotics) and two-fold treatment (2 μg/ml for meropenem and 8 μg/ml for fosfomycin) were sufficient to suppress the growth of the control strains. One-fold rinse of samples with colistin eliminated their antibacterial activity completely. The marked activity of the samples with meropenem and fosfomycin persisted against the antibiotic-sensitive P. aeruginosa ATCC 27853 strain after 2 rinse cycles; single-rinsed samples with fosfomycin also maintained the activity against the extensively antibioticresistant P. aeruginosa BP-150 strain. Vancomycin-containing samples possessed the sufficient antibacterial activity against both methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) S. aureus strains; two-fold rinse of the samples eliminated their bactericidal properties.Conclusion. Bone cement based coatings impregnated with fosfomycin and meropenem possess the most marked and long-lasting antibacterial activity, manifested mainly against the antibiotic-sensitive strains. 

scholarly journals Identification of Substances Produced by Cercospora brachiata in Absence of Light and Evaluation of Antibacterial Activity

2021 ◽  
Vol 7 (9) ◽  
pp. 680
Author(s):  
John K. R. P. Felisbino ◽  
Bruno S. Vieira ◽  
Alberto de Oliveira ◽  
Neiliane A. da Silva ◽  
Carlos H. G. Martins ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acids ◽  
Antibacterial Activity ◽  
Ethyl Acetate Extract ◽  
Phytopathogenic Fungus ◽  
Broth Microdilution ◽  
Actinomyces Naeslundii ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Almost All

Cercospora brachiata is a phytopathogenic fungus. To know more about the metabolites produced by this fungus, the objective of this work was to identify, isolate and characterize substances present in extracts of the growth broth and mycelium, using gas chromatography with mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). It was also objective to evaluate the antibacterial activity of the extracts. Among the compounds identified, fatty acids, esters, and steroids can be highlighted. The main compounds identified are 9-hexadecenoic, hexadecenoic, oleic, octadecanoic, lauric, myristic, palmitic, doceno-13-enoic, stearic, linoleic, and nonadecanoic acids present in almost all extracts. For the antibacterial activity, the broth microdilution method was used. The ethyl acetate extract of the mycelium presented inhibitory concentrations (MICs) against the bacterium Actinomyces naeslundii (100 μg mL−1) and Streptococcus sanguinis (200 μg mL−1). Finally, two steroids were isolated and identified in the hexane extract of mycelium: ergosta-6,22-dien-3β,5α,8α-triol and brassicasterol.

scholarly journals Development, optimization, standardization, and validation of a simple in-house agar gradient method to determine minimum inhibitory concentration of vancomycin for Staphylococcus aureus

2019 ◽  
Vol 11 (03) ◽  
pp. 220-228
Author(s):  
Sumit Rai ◽  
Mukta Tandon ◽  
Narendra Pal Singh ◽  
Vikas Manchanda ◽  
Iqbal Rajinder Kaur
Keyword(s):  
Staphylococcus Aureus ◽  
Gradient Method ◽  
Inhibitory Concentration ◽  
Control Strain ◽  
Broth Microdilution ◽  
Clinical Strains ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Commercial Strip ◽  
Validation Stage

Abstract BACKGROUND: The Clinical and Laboratory Standards Institute recommends reporting minimum inhibitory concentration (MIC) values of vancomycin for Staphylococcus aureus. Commercial MIC strips are expensive, and the traditional broth microdilution method is cumbersome. With this background, we attempted to develop and standardize an in-house agar gradient method to determine MIC values of vancomycin for S. aureus. OBJECTIVES: To develop and validate an in-house vancomycin MIC strip, based on simple agar gradient method for S. aureus as per bioassay development guidelines. MATERIALS AND METHODS: Filter paper gradient strips were made in house and impregnated with varying concentrations of vancomycin to create an antibiotic gradient. During standardization, MICs of ninety clinical strains of S. aureus and ATCC 29213 were tested by the broth microdilution and commercial strip followed by the in-house strip. During the validation stage, MICs of ninety different clinical strains of S. aureus and ATCC 29213 were determined by the in-house strip followed by MIC detection by broth microdilution and commercial strips. A reading of more than ± 1log2 dilution compared with broth microdilution was considered as an outlier. RESULTS: During the initial stage, there were 7/90 outliers in the clinical strains, and no outliers were seen with the ATCC 29213 control strain. Corrective action included increasing precaution during the antibiotic impregnation on the strip. During validation stage, only 4/90 outliers were observed in the clinical strains. The commercial strips had 29/90 among clinical and 15/30 outliers in the control strain during the prevalidation phase. Despite maintaining cold chain during the validation phase, the outliers for commercial strip were 18/90 and 4/30 for clinical and control strains, respectively. CONCLUSION: Reporting vancomycin MIC for S. aureus may be attempted using the in-house method after validating it with a gold standard broth microdilution method and quality control as per protocol.

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