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

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.

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EFFECTS OF ALPHA-MANGOSTIN AND CITRONELLA OIL AGAINST ACNE CAUSING BACTERIA

International Journal of Pharmacy and Pharmaceutical Sciences ◽

10.22159/ijpps.2019v11i6.32927 ◽

2019 ◽

pp. 45-49

Author(s):

PIANGPETCH TANNGOEN ◽

Supaporn Lamlertthon ◽

Waree Tiyaboonchai

Keyword(s):

Inhibitory Concentration ◽

Inhibitory Effect ◽

Diffusion Method ◽

Disk Diffusion Method ◽

Citronella Oil ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Natural Agent ◽

And Staphylococcus Aureus ◽

Concentration Indices

Objective: This study assessed the effects of alpha-mangostin (AM) and citronella oil (CO) working alone or in combination against Propionibacterium acnes (P. acnes) and Staphylococcus aureus (S. aureus). Methods: The screening for antibacterial activity of AM and CO against P. acnes and S. aureus was carried out using the disk diffusion method. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these two substances were determined using the broth microdilution method. The fractional inhibitory concentration indices (FICI) of a combination of AM and CO were obtained by checkerboard dilution assay. Results: The results showed that alpha-mangostin and citronella oil do indeed fight against P. acnes and S. aureus. The MICs and MBCs of AM against P. acnes and S. aureus were the same at 6.25 and 50 µg/ml, respectively. Both the MIC and the MBC of CO against P. acnes were 27.81µg/ml. The MIC and the MBC of CO against S. aureus were 112.13 and 224.25 µg/ml, respectively. The FICI of a combination of AM and CO against P. acnes and S. aureus were 2.00, indicating indifferent interaction with no additional inhibitory effect. Conclusion: AM and CO are very effective against P. acnes and S. aureus, nevertheless their effect when used together was indifferent from using alone. Further research may find that either or both of these substances combined with yet a different natural agent could provide synergy againstP. acnes and S. aureus.

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

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2015/175983 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 4

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.

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A Pilot Study of the Synergy between Two Antimicrobial Peptides and Two Common Antibiotics

Antibiotics ◽

10.3390/antibiotics8020060 ◽

2019 ◽

Vol 8 (2) ◽

pp. 60 ◽

Cited By ~ 11

Author(s):

Franziska Kampshoff ◽

Mark D. P. Willcox ◽

Debarun Dutta

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Agents ◽

Inhibitory Concentration ◽

Synergistic Activity ◽

Fractional Inhibitory Concentration ◽

First Line ◽

Checkerboard Assay ◽

Resistant Strains ◽

And Staphylococcus Aureus ◽

Broth Dilution

Background: Frequent and unrestricted use of antibiotics has been associated with the development of antibiotic resistance by microorganisms. Thus, there is a need to find novel antibacterial agents or a combination of agents as the first line of treatment for various infections. This study aimed to investigate the synergy between antimicrobial peptide (AMP) combinations or between AMP-antibiotics combinations using two common pathogens, Pseudomonas aeruginosa and Staphylococcus aureus. Methods: The AMPs melimine, Mel4 and protamine, and antibiotics cefepime and ciprofloxacin were used in this study. The minimum inhibitory concentration (MIC) of each were evaluated against P. aeruginosa and S. aureus strains by a microtiter broth dilution. Based on the MIC of each antimicrobial agent, a checkerboard assay was performed to investigate the synergy between them, which was expressed as the fractional inhibitory concentration (FIC). Results: The combination of melimine and ciprofloxacin showed synergistic activity against antibiotic sensitive or resistant strains of P. aeruginosa and with FIC values ≤0.5. Conclusion: Combinations of AMPs and the fluoroquinolone ciprofloxacin is a promising method for reducing resistance to the fluoroquinolone of P. aeruginosa.

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Curcumin, a Natural Antimicrobial Agent with Strain-Specific Activity

Pharmaceuticals ◽

10.3390/ph13070153 ◽

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.

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Results from the China Antimicrobial Surveillance Network (CHINET) in 2017 of the In Vitro Activities of Ceftazidime-Avibactam and Ceftolozane-Tazobactam against Clinical Isolates of Enterobacteriaceae and Pseudomonas aeruginosa

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02431-18 ◽

2019 ◽

Vol 63 (4) ◽

Cited By ~ 19

Author(s):

Dandan Yin ◽

Shi Wu ◽

Yang Yang ◽

Qingyu Shi ◽

Dong Dong ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Clinical Isolates ◽

Surveillance Network ◽

Content Type ◽

Highly Active ◽

Microdilution Method ◽

Carbapenem Resistant ◽

Antimicrobial Surveillance ◽

Broth Microdilution Method

ABSTRACT The in vitro activities of ceftazidime-avibactam (CZA), ceftolozane-tazobactam (C-T), and comparators were determined for 1,774 isolates of Enterobacteriaceae and 524 isolates of Pseudomonas aeruginosa collected by 30 medical centers from the China Antimicrobial Surveillance Network (CHINET) in 2017. Antimicrobial susceptibility testing was performed by the CLSI broth microdilution method, and blaKPC and blaNDM were detected by PCR for all carbapenem-resistant Enterobacteriaceae (CRE). Ceftazidime-avibactam demonstrated potent activity against almost all Enterobacteriaceae (94.6% susceptibility; MIC50, ≤0.25 mg/liter; MIC90, ≤0.25 to >32 mg/liter) and good activity against P. aeruginosa (86.5% susceptibility; MIC50/90, 2/16 mg/liter). Among the CRE, 50.8% (189/372 isolates) were positive for blaKPC-2, which mainly existed in ceftazidime-avibactam-susceptible Klebsiella pneumoniae isolates (92.1%, 174/189). Among the CRE, 17.7% (66/372 isolates) were positive for blaNDM, which mainly existed in strains resistant to ceftazidime-avibactam (71.7%, 66/92). Ceftolozane-tazobactam showed good in vitro activity against Escherichia coli and Proteus mirabilis (MIC50/90, ≤0.5/2 mg/liter; 90.5 and 93.8% susceptibility, respectively), and the rates of susceptibility of K. pneumoniae (MIC50/90, 2/>64 mg/liter) and P. aeruginosa (MIC50/90, 1/8 mg/liter) were 52.7% and 88.5%, respectively. Among the CRE strains, 28.6% of E. coli isolates and 85% of K. pneumoniae isolates were still susceptible to ceftazidime-avibactam, but only 7.1% and 1.9% of them, respectively, were susceptible to ceftolozane-tazobactam. The rates of susceptibility of the carbapenem-resistant P. aeruginosa isolates to ceftazidime-avibactam (65.7%) and ceftolozane-tazobactam (68%) were similar. Overall, both ceftazidime-avibactam and ceftolozane-tazobactam were highly active against clinical isolates of Enterobacteriaceae and P. aeruginosa recently collected across China, and ceftazidime-avibactam showed activity superior to that of ceftolozane-tazobactam against Enterobacteriaceae, whereas ceftolozane-tazobactam showed a better effect against P. aeruginosa.

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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.46.9.3039-3041.2002 ◽

2002 ◽

Vol 46 (9) ◽

pp. 3039-3041 ◽

Cited By ~ 144

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.

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Antibacterial Activity of Parijoto (Medinilla speciosa Blume) Fruit Against Serratia marcescens and Staphylococcus aureus

Indonesian Journal of Pharmaceutical Science and Technology ◽

10.24198/ijpst.v8i2.32166 ◽

2021 ◽

Vol 8 (2) ◽

pp. 76

Author(s):

Tiana Milanda ◽

Keri Lestari ◽

Nimas T. I. Tarina

Keyword(s):

Antibacterial Activity ◽

Ethyl Acetate ◽

Serratia Marcescens ◽

Local Community ◽

Inhibitory Concentration ◽

Methanol Extract ◽

Clinical Isolates ◽

Central Java ◽

Anti Cancer ◽

And Staphylococcus Aureus

Parijoto (Medinilla speciosa Blume) is a plant found in Mount Muria, Kudus, Central Java. The local community often uses its fruit to treat various diseases, as well as antibacterial, anti-inflammatory, antioxidant, and anti-cancer. This study aimed to determine the antibacterial activity of n-hexane, ethyl acetate and methanol extract from parijoto fruit against Staphyococcus aureus ATCC 29213 and Serratia marcescens clinical isolates. Gradual maceration of simplicial and antibacterial activity testing of the extracts was performed, followed by determining the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and comparative antibacterial activity most active extract against ampicillin and cefadroxil. The results showed that all extracts exhibited activity against S. aureus ATCC 29213, but only ethyl acetate and methanol extracts had activity against S. marcescens clinical isolates. The highest antibacterial activity was shown by the methanol extract, which was more effective against S. aureus ATCC 29213, having the largest inhibition diameter and lowest MIC and MBC values (6.25 and 12.5 mg/mL). The comparative analysis indicated that the methanol extract demonstrated lower antibacterial activity against S. aureus ATCC 29213 than cefadroxil (72,511: 1). This antibacterial activity is presumed to be generated from alkaloids, polyphenols, tannins, flavonoids, quinones and saponina in the extract.Keywords: Amoxicillin, Cefadroxil, MIC, MBC

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

BMC Research Notes ◽

10.1186/s13104-021-05838-8 ◽

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.

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

Canadian Journal of Infectious Diseases and Medical Microbiology ◽

10.1155/2021/7029944 ◽

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.

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

Journal of Experimental and Clinical Medicine ◽

10.52142/omujecm.38.4.24 ◽

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.

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