GC-FID Analysis and Antibacterial Activity of the Calyptranthes concinna Essential Oil against MDR Bacterial Strains

Presently, results from a study carried out in this area using the essential oil from the Calyptranthes concinna species, a representative from the Myrtaceae family, are reported. The essential oil was obtained by hydrodistillation and gas chromatography coupled to mass spectrometry was used to identify its chemical constituents. Antibacterial activity was determined using the broth microdilution method, thus obtaining the Minimal Inhibitory Concentration (MIC) value, from which the subinhibitory concentration (MIC/8) was derived. The C. concinna essential oil presented antibacterial activity against both standard and multiresistant bacteria. In addition, the oil demonstrated an antibiotic activity potentiation against Staphylococcus aureus and Escherichia coli when in combination with the antibiotic gentamicin, reducing the MIC from 141.38 μg/mL and 208.63 μg/mL to 64 μg/mL and 128 μg/mL, respectively. Conclusions: Findings from the present study suggest this oil is promising in terms of its antimicrobial activity.

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Antibacterial Activity of the Essential Oil of Heracleum Sibiricum

Natural Product Communications ◽

10.1177/1934578x1300800931 ◽

2013 ◽

Vol 8 (9) ◽

pp. 1934578X1300800 ◽

Cited By ~ 4

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.

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In vitro Antibacterial Activity of Libanotis montana Essential Oil in Combination with Conventional Antibiotics

Natural Product Communications ◽

10.1177/1934578x1400900238 ◽

2014 ◽

Vol 9 (2) ◽

pp. 1934578X1400900 ◽

Cited By ~ 4

Author(s):

Dragoljub L. Miladinović ◽

Budimir S. Ilić ◽

Tatjana M. Mihajilov-Krstev ◽

Jovana L. Jović ◽

Marija S. Marković

Keyword(s):

Gas Chromatography ◽

Antibacterial Activity ◽

Chemical Composition ◽

Essential Oil ◽

Hierarchical Cluster ◽

Gas Chromatography Mass Spectrometry ◽

Bacterial Strains ◽

Microdilution Method ◽

Broth Microdilution Method

The chemical composition and antibacterial activity were examined of Libanotis montana Crantz subsp. leiocarpa (Heuff.) Soó. (Apiaceae) essential oil. Gas chromatography and gas chromatography/mass spectrometry were used to analyze the chemical composition of the oil. The antibacterial activity was investigated by the broth microdilution method against thirteen bacterial strains. The interactions of the essential oil and three standard antibiotics: tetracycline, streptomycin and chloramphenicol toward five selected strains were evaluated using the microdilution checkerboard assay in combination with chemometric methods: principal components analysis and hierarchical cluster analysis. Sesquiterpene hydrocarbons were the most abundant compound class in the oil (67.2%), with β-elemene (40.4%) as the major compound. The essential oil exhibited slight antibacterial activity against the tested bacterial strains in vitro, but the combinations L. montana oil-chloramphenicol and L. montana oil-tetracycline exhibited mostly either synergistic or additive interactions. These combinations reduced the minimum effective dose of the antibiotics and, consequently, minimized their adverse side effects. In contrast, the association of L. montana essential oil and streptomycin was characterized by strong antagonistic interactions against Escherichia coli ATCC 25922. In the PCA and HCA analyses, streptomycin stood out and formed a separate group.

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Antibacterial evaluation of Styrax pohlii and isolated compounds

Brazilian Journal of Pharmaceutical Sciences ◽

10.1590/s1984-82502013000400004 ◽

2013 ◽

Vol 49 (4) ◽

pp. 653-658 ◽

Cited By ~ 7

Author(s):

Camila Spereta Bertanha ◽

Susane Hellen Utrera ◽

Valéria Maria Melleiro Gimenez ◽

Milton Groppo ◽

Márcio Luis Andrade e Silva ◽

...

Keyword(s):

Antibacterial Activity ◽

Inhibitory Concentration ◽

Ethanolic Extract ◽

Preliminary Evaluation ◽

Microdilution Method ◽

Aerial Parts ◽

Broth Microdilution Method ◽

Weak Antibacterial Activity ◽

Mic Value

The antibacterial activity of the compounds egonol (1) and homoegonol (2), of the crude ethanolic extract of Styrax pohlii (Styracaceae) aerial parts (EE), and of its n-hexane (HF), EtOAc (EF), n-BuOH (BF), and hydromethanolic (HMF) fractions was evaluated against the following microorganisms: Streptococcus pneumoniae (ATCC 6305), S. pyogenes (ATCC 19615), Haemophilus influenzae (ATCC 10211), Pseudomonas aeruginosa (ATCC 27853), and Klebsiella pneumoniae (ATCC 10031). The broth microdilution method was used for determination of the minimum inhibitory concentration (MIC) during preliminary evaluation of antibacterial activity. The EE yielded MIC values of 400 µg/mL for S. pneumoniae and P. aeruginosa and 300 µg/mL for H. influenzae. The HF and EF fractions exhibited enhanced antibacterial activity, with MIC values of 200 µg/mL against S. pneumoniae, but only EF displayed activity against H. influenzae (MIC 200 µg/mL). The best MIC value with compounds 1 and 2 (400 µg/mL) was obtained for (1) against S. pneumoniae and P. aeruginosa. Therefore, 1 exhibited weak antibacterial activity against these standard strains.

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

Natural Product Communications ◽

10.1177/1934578x1801300325 ◽

2018 ◽

Vol 13 (3) ◽

pp. 1934578X1801300 ◽

Cited By ~ 2

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.

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Synthesis and Antibacterial Activities of Amidine Substituted Monocyclic β-Lactams

Medicinal Chemistry ◽

10.2174/1573406417666210830122954 ◽

2021 ◽

Vol 17 ◽

Author(s):

Lijuan Zhai ◽

Lili He ◽

Yuanbai Liu ◽

Ko Ko Myo ◽

Zafar Iqbal ◽

...

Keyword(s):

Antibacterial Activity ◽

Bacterial Species ◽

Antimicrobial Effect ◽

Antibacterial Activities ◽

Lead Target ◽

Bacterial Strains ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Clinical Interest

Background: Mononcyclic β-lactams are regarded as the most resistant class of β-lactams against a series of β-lactamases though possess limited antibacterial activity. Aztreonam being the first clinically approved monobactam needs broad-spectrum efficacy through structural modification. Objective: We strive to synthesize a number of monocyclic β-lactams by varying the substituents at N1, C3 and C4 positions of azetidinone ring and study the antimicrobial effect on variable bacterial strains. Methods: Seven new monobactam derivatives 23a-g, containing substituted-amidine moieties linked to the azetidinone ring via thiazole linker, were synthesized through multistep synthesis. The final compounds were investigated for their in vitro antibacterial activities using broth microdilution method, against ten bacterial strains of clinical interest. The minimum inhibitory concentrations (MICs) of newly synthesized derivatives were compared with aztreonam, ceftazidime and meropenem, existing clinical antibiotics. Results: All compounds 23a-g showed higher antibacterial activities (MIC 0.25 µg/mL to 64 µg/mL) against tested strains as compared to aztreonam (MIC 16 µg/mL to >64 µg/mL) and ceftazidime (MIC >64 µg/mL). However all compounds, except 23d, exhibited lower antibacterial activity against all tested bacterial strains as compared to meropenem. Conclusion: Compound 23d showed comparable or improved antibacterial activity (MIC 0.25 µg/mL to 2 µg/mL) to meropenem (MIC 1 µg/mL to 2 µg/mL) in case of seven bacterial species. Therefore, compound 23d may be valuable lead target for further investigations against multi-drug resistant Gram-negative bacteria.

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

Traumatology and Orthopedics of Russia ◽

10.21823/2311-2905-2018-24-4-105-110 ◽

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.

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Chemical Composition, and Evaluation of Antibacterial，Antibiofilm and Synergistic Effects with Conventional Antibiotics of Essential Oil from Mallotus repandus

Records of Natural Products ◽

10.25135/rnp.217.20.10.1854 ◽

2021 ◽

Vol 15 (4) ◽

pp. 324-329

Author(s):

Pengxiang Lai ◽

Xin-Chen Zhang ◽

Lin Zhu ◽

Xin-Yu Li ◽

Li-Chuan Liu

Keyword(s):

Essential Oil ◽

Biofilm Formation ◽

Synergistic Effects ◽

Antibacterial Properties ◽

Good Alternative ◽

Bactericidal Effect ◽

Bacterial Strains ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Mallotus Repandus

The essential oil (EO) of aerial parts of Mallotus repandus (Willd.) Muell. Arg. was extracted by hydrodistillation and characterized by GC/FID and GC/MS. Fifty-one compounds comprising 97.1% of the EO were identified, of which α-humulene (18.7%), β-selinene (12.8%), aciphyllene (10.7%), (E)-caryophyllene (8.4%), α-copaene (5.5%), humulene epoxide II (4.9%) and caryophyllene oxide (4.3%) were the major compounds. The EO was evaluated for antibacterial properties using broth microdilution method and crystal-violet static biofilm formation assay. The M. repandus EO possessed a bactericidal effect against tested gram-positive bacteria strains (MIC = MBC: 0.05-0.10 mg/mL). Further, the EO showed the ability to inhibit the biofilm formation of Staphylococcus aureus. In addition, the potential synergistic effect was assessed by checkerboard method. Combination of the M. repandus EO with Streptomycin showed synergistic effects against the tested bacterial strains. This study demonstrates that M. repandus EO could be further explored as good alternative for potential pharmaceuticals.

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Antibacterial Activity of the Essential Oil of Lippia oreganoides against Multiresistant Bacterial Strains of Nosocomial Origin

Natural Product Communications ◽

10.1177/1934578x0700200117 ◽

2007 ◽

Vol 2 (1) ◽

pp. 1934578X0700200 ◽

Cited By ~ 13

Author(s):

Judith Velasco ◽

Janne Rojas ◽

Poema Salazar ◽

Mariseg Rodríguez ◽

Tulia Díaz ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Essential Oil ◽

Low Dose ◽

Methicillin Resistant Staphylococcus Aureus ◽

Pharmaceutical Preparations ◽

Bacterial Strains ◽

Multiresistant Bacteria ◽

Agar Method ◽

First Time

Antibacterial activity of the essential oil of Lippia oreganoides was evaluated against thirty-nine multiresistant bacterial strains of nosocomial origin and five reference bacterial strains using the disk diffusion agar method. The results obtained have revealed strong antibacterial activity against methicillin resistant Staphylococcus aureus, extended spectrum β-lactamase producing Klebsiella pneumoniae, and multiresistant Acinetobacter baumannii with MIC values ranging from 20 to 40 μg/mL. The low dose antibacterial activity observed in this investigation suggested that the essential oil of L. oreganoides could be used in pharmaceutical preparations for the treatment of infections caused by multiresistant bacteria. According to the literature consulted, this is the first time that antibacterial activity of this species against multiresistant bacterial strains of nosocomial origin has been reported.

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Enhancement of Antibiotic Activity by 1,8-Naphthyridine Derivatives against Multi-Resistant Bacterial Strains

Molecules ◽

10.3390/molecules26237400 ◽

2021 ◽

Vol 26 (23) ◽

pp. 7400

Author(s):

José B. de Araújo-Neto ◽

Maria M. C. da Silva ◽

Cícera D. de M. Oliveira-Tintino ◽

Iêda M. Begnini ◽

Ricardo A. Rebelo ◽

...

Keyword(s):

Bacterial Infections ◽

Bacterial Resistance ◽

Antimicrobial Properties ◽

Multidrug Resistant ◽

Antibiotic Activity ◽

Bacterial Strains ◽

Microdilution Method ◽

Fluoroquinolone Antibiotics ◽

Broth Microdilution Method ◽

Resistant Strains

The search for new antibacterial agents has become urgent due to the exponential growth of bacterial resistance to antibiotics. Nitrogen-containing heterocycles such as 1,8-naphthyridine derivatives have been shown to have excellent antimicrobial properties. Therefore, the purpose of this study was to evaluate the antibacterial and antibiotic-modulating activities of 1,8-naphthyridine derivatives against multi-resistant bacterial strains. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of the following compounds: 7-acetamido-1,8-naphthyridin-4(1H)-one and 3-trifluoromethyl-N-(5-chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide. The antibiotic-modulating activity was analyzed using subinhibitory concentrations (MIC/8) of these compounds in combination with norfloxacin, ofloxacin, and lomefloxacin. Multi-resistant strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were used in both tests. Although the compounds had no direct antibacterial activity (MIC ≥ 1.024 µg/mL), they could decrease the MIC of these fluoroquinolones, indicating synergism was obtained from the association of the compounds. These results suggest the existence of a structure–activity relationship in this group of compounds with regard to the modulation of antibiotic activity. Therefore, we conclude that 1,8-naphthyridine derivatives potentiate the activity of fluoroquinolone antibiotics against multi-resistant bacterial strains, and thereby interesting candidates for the development of drugs against bacterial infections caused by multidrug resistant strains.

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Antibacterial and Antibiotic-Potentiating Activities of Thirteen Cameroonian Edible Plants against Gram-Negative Resistant Phenotypes

The Scientific World JOURNAL ◽

10.1155/2018/4020294 ◽

2018 ◽

Vol 2018 ◽

pp. 1-14 ◽

Cited By ~ 2

Author(s):

Paul Nayim ◽

Armelle T. Mbaveng ◽

Brice E. N. Wamba ◽

Aimé G. Fankam ◽

Joachim K. Dzotam ◽

...

Keyword(s):

Antibacterial Activities ◽

Multidrug Resistant ◽

Bark Extract ◽

Minimal Bactericidal Concentration ◽

Edible Plants ◽

Bacterial Strains ◽

Gram Negative ◽

Microdilution Method ◽

Multiresistant Bacteria ◽

Broth Microdilution Method

This work was designed to investigate the antibacterial activities of methanol extracts from thirteen Cameroonian edible plants and their antibiotic-potentiating effects against Gram-negative multidrug-resistant (MDR) phenotypes. The broth microdilution method was used to evaluate the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extracts, as well as their antibiotic-potentiating activities. The phytochemical screening of the extracts was carried out according to the standard methods. The results of phytochemical tests revealed the presence of sterols, polyphenols, and tannins in most of the tested extracts, with the other classes of secondary metabolites being selectively distributed. Tested extracts showed variable antibacterial activities with MIC values ranging from 64 to 1024 μg/mL. However, some extracts were significantly active against certain bacterial strains: seeds extract of Theobroma cacao (64 μg/mL) against Escherichia coli AG100Atet and Klebsiella pneumoniae K24, and the bark extract of Uapaca guineensis against E. coli ATCC 8739. The leaves extract of T. cacao displayed the best MBC values (256 μg/mL) against E. aerogenes EA27. Some tested extracts included extracts from the leaves of T. cacao and P. vulgaris, and the seeds of D. edulis and barks A. indica has selectively improved (2- to 64-fold) the antibacterial activities of some of the tested antibiotics, chloramphenicol (CHL), tetracycline (TET), kanamycin (KAN), streptomycin (STR), and erythromycin (ERY), against more than 70% of tested MDR bacteria. The findings of this work showed that tested plant extracts and particularly those from T. cacao and Phaseolus vulgaris can be used alone or in combination with conventional antibiotics in the treatment of infections involving multiresistant bacteria.

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