Etomidate inhibits the growth of MRSA and exhibits synergism with oxacillin

2020 ◽  
Vol 15 (17) ◽  
pp. 1611-1619
Author(s):  
Lívia G do AV Sá ◽  
Cecília R da Silva ◽  
João B de A Neto ◽  
Thiago M Cândido ◽  
Leilson C de Oliveira ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Antimicrobial Activity ◽  
Cell Death ◽  
Antibacterial Activity ◽  
Antibacterial Effect ◽  
Broth Microdilution ◽  
Action Mechanism ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Mrsa Strains

Aim: The purpose of this study was to evaluate the antimicrobial activity of the anesthetic etomidate against strains of MRSA and biofilms. Materials & methods: The antibacterial effect of etomidate was assessed by the broth microdilution method. To investigate the probable action mechanism of the compound flow cytometry techniques were used. Results: MRSA strains showed MIC equal to 500 and 1000 μg/ml of etomidate. Four-fifths (80%) of the tested MRSA strains demonstrated synergistic effect with oxacillin. Etomidate also showed activity against MRSA biofilm at concentration of 250 μg/ml. Cytometric analysis revealed that the cells treated with etomidate leading to cell death, probably by apoptosis. Conclusion: Etomidate showed antibacterial activity against MRSA.

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.

Antimicrobial Essential Oil Combinations to Combat Foot Odour

Planta Medica ◽  
2018 ◽  
Vol 84 (09/10) ◽  
pp. 662-673 ◽  
Author(s):  
Ané Orchard ◽  
Alvaro Viljoen ◽  
Sandy van Vuuren
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oil ◽  
Essential Oils ◽  
Antimicrobial Efficacy ◽  
Juniperus Virginiana ◽  
Broth Microdilution ◽  
Synergistic Interactions ◽  
Microdilution Method ◽  
Broth Microdilution Method

AbstractFoot odour (bromodosis) is an embarrassing and perplexing condition mostly caused by bacteria of the Brevibacterium species. Essential oils are a credible option as an affordable treatment of odour and contribute towards antimicrobial efficacy. Therefore, this study sets out to investigate the antimicrobial activity of essential oil combinations against odour-causing bacteria. The broth microdilution method was used to investigate the antimicrobial activity of 119 essential oil combinations, and the fractional inhibitory index was calculated to determine the interactive profile. Combinations that resulted in synergy in 1 : 1 ratios were further evaluated in different concentrations, and isobolograms were plotted to determine the influence of the ratio on overall activity. Numerous combinations could be identified as having synergistic interactions against the Brevibacterium spp. and no antagonism was observed. The combination of Juniperus virginiana (juniper) and Styrax benzoin (benzoin) demonstrated synergy against all three Brevibacterium spp. tested and J. virginiana was the essential oil responsible for the majority of the synergistic interactions. The results reported here confirm the promising potential of the majority of these oils and selected combinations in treating and controlling bromodosis.

scholarly journals Flow Cytometry Antifungal Susceptibility Testing of Pathogenic Yeasts other than Candida albicans and Comparison with the NCCLS Broth Microdilution Test

2000 ◽  
Vol 44 (10) ◽  
pp. 2752-2758 ◽  
Author(s):  
Rama Ramani ◽  
Vishnu Chaturvedi
Keyword(s):  
Flow Cytometry ◽  
Candida Albicans ◽  
Amphotericin B ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
Broth Microdilution ◽  
Nitrogen Base ◽  
Microdilution Method ◽  
Broth Microdilution Method

ABSTRACT Candida species other than Candida albicansfrequently cause nosocomial infections in immunocompromised patients. Some of these pathogens have either variable susceptibility patterns or intrinsic resistance against common azoles. The availability of a rapid and reproducible susceptibility-testing method is likely to help in the selection of an appropriate regimen for therapy. A flow cytometry (FC) method was used in the present study for susceptibility testing ofCandida glabrata, Candida guilliermondii,Candida krusei, Candida lusitaniae,Candida parapsilosis, Candida tropicalis, andCryptococcus neoformans based on accumulation of the DNA binding dye propidium iodide (PI). The results were compared with MIC results obtained for amphotericin B and fluconazole using the NCCLS broth microdilution method (M27-A). For FC, the yeast inoculum was prepared spectrophotometrically, the drugs were diluted in either RPMI 1640 or yeast nitrogen base containing 1% dextrose, and yeast samples and drug dilutions were incubated with amphotericin B and fluconazole, respectively, for 4 to 6 h. Sodium deoxycholate and PI were added at the end of incubation, and fluorescence was measured with a FACScan flow cytometer (Becton Dickinson). The lowest drug concentration that showed a 50% increase in mean channel fluorescence compared to that of the growth control was designated the MIC. All tests were repeated once. The MICs obtained by FC for all yeast isolates except C. lusitaniae were in very good agreement (within 1 dilution) of the results of the NCCLS broth microdilution method. Paired ttest values were not statistically significant (P = 0.377 for amphotericin B; P = 0.383 for fluconazole). Exceptionally, C. lusitaniae isolates showed higher MICs (2 dilutions or more) than in the corresponding NCCLS broth microdilution method for amphotericin B. Overall, FC antifungal susceptibility testing provided rapid, reproducible results that were statistically comparable to those obtained with the NCCLS method.

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 Antimicrobial Activity of Exebacase (Lysin CF-301) against the Most Common Causes of Infective Endocarditis

2019 ◽  
Vol 63 (10) ◽  
Author(s):  
Aubrey Watson ◽  
Jun Taek Oh ◽  
Karen Sauve ◽  
Patricia A. Bradford ◽  
Cara Cassino ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Cell Wall ◽  
Infective Endocarditis ◽  
Broth Microdilution ◽  
Coagulase Negative Staphylococci ◽  
Content Type ◽  
Microdilution Method ◽  
Cell Wall Hydrolase ◽  
Broth Microdilution Method ◽  
Common Causes

ABSTRACT Exebacase, a recombinantly produced lysin (cell wall hydrolase), and comparator antibiotics were tested by the broth microdilution method against strain sets of Staphylococcus and Streptococcus spp., which are the most common causes of infective endocarditis in humans. Exebacase was active against all Staphylococcus spp. tested, including S. aureus and coagulase-negative staphylococci (MIC50/90, 0.5/1 μg/ml). Activity against Streptococcus spp. was variable, with S. pyogenes, S. agalactiae, and S. dysgalactiae (MIC50/90, 1/2 μg/ml) among the most susceptible.

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.

Chemical composition and antimicrobial activity of Erodium species: E. ciconium L., E. cicutarium L., and E. absinthoides Willd. (Geraniaceae)

2010 ◽  
Vol 64 (3) ◽  
Author(s):  
Zorica Stojanović-Radić ◽  
Ljiljana Čomić ◽  
Niko Radulović ◽  
Milan Dekić ◽  
Vladimir Ranđelović ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Essential Oils ◽  
Palmitic Acid ◽  
Gram Negative Bacteria ◽  
Broth Microdilution ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Microdilution Method ◽  
Broth Microdilution Method

AbstractThe present study gives results of chemical composition analyses and antimicrobial activity testing of three Erodium species: E. ciconium L., E. cicutarium L., and E. absinthoides Willd. Essential oils were obtained by hydro-distillation from air-dried entire plants and analyzed by GC and GC-MS. A total of 209 different compounds were identified: 162 for E. cicutarium, 107 for E. ciconium, and 79 for E. absinthoides. Antimicrobial activity (broth microdilution method) of the oils was screened against a panel of Gram positive and Gram negative bacteria and a number of fungi. Moderate susceptibility of all tested strains was observed. Determined MIC values were 0.156–5 mg mL−1 (bacterial strains) and 0.039–0.325 mg mL−1 (fungal strains). Major component of the most active oil, palmitic acid, was also tested for activity together with stearic and myristic acids.

scholarly journals Susceptibility to antibiotic combinations of Klebsiella pneumoniae and Acinetobacter baumannii strains isolated from COVID-19 patients

2021 ◽  
Vol 18 (4) ◽  
pp. 33-40
Author(s):  
D. V. Tapalski ◽  
E. V. Karpova
Keyword(s):  
Klebsiella Pneumoniae ◽  
Bactericidal Activity ◽  
Antibacterial Effect ◽  
Bactericidal Effect ◽  
Bacteriostatic Activity ◽  
Broth Microdilution ◽  
Colistin Resistance ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Broth Microdilution Method

Objective. To assess the susceptibility of K.pneumoniae and A.baumanii strains isolated from hospitalized COVID-19 patients to antibiotics and their combinations.Materials and methods. The minimum inhibitory concentrations (MICs) of meropenem and colistin were determined for 47 A.baumannii and 51K.pneumoniaestrains isolated from the hospitalized COVID-19 patients by the broth microdilution method. The susceptibility to 11 antibiotic combinations was assessed using the method of multiple combination bactericidal testing.Results. Colistin resistance was detected in 31.9 % of A.baumannii strains (MIC50 — 0.5 mg/l, MIC90 — 16 mg/l) and in 80.4 % of K.pneumoniaestrains (MIC50 — 16 mg/l, MIC90 — 256 mg/l). It has been shown that double antibiotic combinations with the inclusion of colistin exhibit bactericidal or bacteriostatic activity against 76.6–87.2 % of A.baumannii strains. Combinations with the addition of meropenem, colistin and macrolides exhibited bactericidal activity against 78.4–80.4 % of K.pneumoniae strains. Combinations of two carbapenems were not active, the combination of meropenem-colistin had a bactericidal effect only in 13.7 % of K.pneumoniae strains.Conclusion. Widespread colistin resistance was found in carbapenem-resistant K.pneumoniae and A.baumannii strains isolated from the hospitalized COVID-19 patients. The combinations of antibiotics that have a synergistic antibacterial effect in their pharmacokinetic/pharmacodynamic concentrations have been determined.

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