ANTIMICROBIAL ACTIVITY OF THUJA ORIENTALIS IN COMBINATION WITH CIPROFLOXACIN AGAINST PSEUDOMONAS AERUGINOSA

Disc Diffusion ◽

Thuja Orientalis

OBJECTIVES: To compare the combined antimicrobial effect of Thuja orientalis and Ciprofloxacin against Pseudomonas aeruginosa in vitro samples. METHODS: In-vitro antibacterial activity of plant-extracts was evaluated alone and in combination with ciprofloxacin against Pseudomonas aeruginosa using disc-diffusion susceptibility assay (Kirby Bauer method) and minimum inhibitory concentration (96 well broth microdilution method) following CLSI guidelines. Pseudomonas aeruginosa clinical strains were collected from Rehman Medical Institute (RMI) and Northwest General Hospital Peshawar, Pakistan and ATCC strains (no.9721) of this bacterium were collected from Agriculture University Peshawar. The organism was tested six times with crude extract and fractionation with different solvents such as n-hexane, chloroform, ethyl acetate and butanol at concentrations of 1, 4, 8, 12, 16, 20, 24, 30 and 36 mg/ml. The mean MIC and FICI (fractional inhibitory concentration index) was obtained to report the synergism. The data were analysed using SPSS version-21. RESULTS: In combination, methanolic crude extract, chloroform and butanol fraction showed synergistic effect at all tested concentrations against Pseudomonas aeruginosa (ATCC 9721 and clinical) except with 1, 4, 16 mg/ml concentrations. Ethyl acetate and aqueous fractions shows indifference and synergistic effect against Pseudomonas aeruginosa (ATCC 9721 and clinical) at different concentrations. The fractional inhibitory concentration index (FICI) ranged from 1.24 to 3.24 against Pseudomonas aeruginosa alone and in combination with ciprofloxacin. CONCLUSION: By disc diffusion method, this study shows synergistic effect against Pseudomonas aeruginosa in combination with ciprofloxacin. However, through minimum inhibitory concentration method, it shows antagonism and indifference but no synergistic effect against different fractions of plant.

In Vitro and Intracellular Activity of Imipenem Combined with Tedizolid, Rifabutin, and Avibactam against Mycobacterium abscessus

10.1128/aac.01915-18 ◽

2019 ◽

Vol 63 (4) ◽

Cited By ~ 12

Author(s):

Eva Le Run ◽

Michel Arthur ◽

Jean-Luc Mainardi

Keyword(s):

Serum Concentration ◽

Synergistic Effect ◽

Bactericidal Activity ◽

Concentration Index ◽

Mycobacterium Abscessus ◽

Fractional Inhibitory Concentration Index

Content Type ◽

ABSTRACT Mycobacterium abscessus infections are difficult to treat because of their resistance to many antibiotics. In vitro, tedizolid combined with imipenem displayed a moderate synergistic effect (fractional inhibitory concentration index, 0.41) but no bactericidal activity. Intracellularly, tedizolid 2 μg/ml (half of the MIC), corresponding to the peak serum concentration, increased the efficacy of imipenem at 8 and 32 μg/ml. Addition of avibactam and rifabutin, alone or in combination, improved the activity of the imipenem-tedizolid combination.

Faculty Opinions recommendation of Defining fractional inhibitory concentration index cutoffs for additive interactions based on self-drug additive combinations, Monte Carlo simulation analysis, and in vitro-in vivo correlation data for antifungal drug combinations against Aspergillus fumigatus.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1282045.749142 ◽

2009 ◽

Author(s):

Annette Fothergill

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Concentration Index ◽

Simulation Analysis ◽

Correlation Data

In vitro synergy of isavuconazole in combination with colistin against Candida auris

Scientific Reports ◽

10.1038/s41598-020-78588-5 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Patrick Schwarz ◽

Anne-Laure Bidaud ◽

Eric Dannaoui

Keyword(s):

Response Surface ◽

Surface Analysis ◽

Concentration Index ◽

Response Surface Analysis ◽

Candida Auris ◽

Agar Diffusion

AbstractThe in vitro interactions of isavuconazole with colistin were evaluated against 15 clinical Candida auris isolates by a microdilution checkerboard technique based on the EUCAST reference method for antifungal susceptibility testing and by agar diffusion using isavuconazole gradient concentration strips with or without colistin incorporated RPMI agar. Interpretation of the checkerboard results was done by the fractional inhibitory concentration index and by response surface analysis based on the Bliss model. By checkerboard, combination was synergistic for 93% of the isolates when interpretation of the data was done by fractional inhibitory concentration index, and for 80% of the isolates by response surface analysis interpretation. By agar diffusion test, although all MICs in combination decreased compared to isavuconazole alone, only 13% of the isolates met the definition of synergy. Essential agreement of EUCAST and gradient concentration strip MICs at +/− 2 log2 dilutions was 93.3%. Antagonistic interactions were never observed for any technique or interpretation model used.

In Vitro Interaction of Posaconazole and Caspofungin against Clinical Isolates of Candida glabrata

10.1128/aac.49.8.3544-3545.2005 ◽

2005 ◽

Vol 49 (8) ◽

pp. 3544-3545 ◽

Cited By ~ 19

Author(s):

E. R. Oliveira ◽

A. W. Fothergill ◽

W. R. Kirkpatrick ◽

B. J. Coco ◽

T. F. Patterson ◽

...

Keyword(s):

Candida Glabrata ◽

Concentration Index ◽

Clinical Isolates ◽

Fluconazole Resistant ◽

In Vitro Interaction

ABSTRACT Combinations of caspofungin and posaconazole were evaluated by fractional inhibitory concentration index against 119 Candida glabrata isolates. Synergy was seen in 18% of all isolates and in 4% of fluconazole-resistant isolates at 48 h without evidence of antagonism. This antifungal combination may have utility against this organism.

In Vitro Interactions of Echinocandins with Triazoles against Multidrug-Resistant Candida auris

10.1128/aac.01056-17 ◽

2017 ◽

Vol 61 (11) ◽

Cited By ~ 39

Author(s):

Hamed Fakhim ◽

Anuradha Chowdhary ◽

Anupam Prakash ◽

Afsane Vaezi ◽

Eric Dannaoui ◽

...

Keyword(s):

Concentration Index ◽

Multidrug Resistant ◽

Candida Auris ◽

Synergistic Interactions ◽

In Vitro Interactions

ABSTRACT We determined the in vitro interactions between echinocandins and azoles against 10 multidrug-resistant Candida auris strains by use of a microdilution checkerboard technique. Our results suggest synergistic interactions between micafungin and voriconazole with fractional inhibitory concentration index (FICI) values of 0.15 to 0.5, and we observed indifferent interactions when micafungin was combined with fluconazole (FICI, 0.62 to 1.5). Combinations of caspofungin with fluconazole or voriconazole exhibited indifferent interactions. No antagonism was observed for any combination.

Synergy between Trovafloxacin and Ceftriaxone against Penicillin-Resistant Pneumococci in the Rabbit Meningitis Model and In Vitro

10.1128/aac.44.8.2179-2181.2000 ◽

2000 ◽

Vol 44 (8) ◽

pp. 2179-2181 ◽

Cited By ~ 15

Author(s):

Philippe Cottagnoud ◽

Fernando Acosta ◽

Marianne Cottagnoud ◽

Klaus Neftel ◽

Martin G. Täuber

Keyword(s):

Clinical Practice ◽

Concentration Index ◽

Killing Rate ◽

Pneumococcal Strain ◽

Bactericidal Activities

ABSTRACT The bactericidal activities of monotherapy with trovafloxacin (−0.37 ± 0.15 Δlog10 CFU/ml · h), vancomycin (−0.32 ± 0.12 Δlog10 CFU/ml · h), and ceftriaxone (−0.36 ± 0.19 Δlog10CFU/ml · h) for the treatment of experimental meningitis in rabbits due to a clinical penicillin-resistant pneumococcal strain (MIC, 4 mg/liter) were similar. The combination of ceftriaxone with trovafloxacin considerably improved the killing rates (−0.67 ± 0.16 Δlog10 CFU/ml · h) and was slightly superior to ceftriaxone with vancomycin (killing rate, −0.53 ± 0.22 Δlog10 CFU/ml · h), the regimen most commonly used in clinical practice. In vitro, synergy was demonstrated between ceftriaxone and trovafloxacin by the checkerboard method (fractional inhibitory concentration index, 0.5) and by time-killing assays over 8 h.

Investigation of Copaifera genus as a new source of antimycobaterial agents

Future Science OA ◽

10.2144/fsoa-2020-0018 ◽

2020 ◽

Vol 6 (7) ◽

pp. FSO587

Author(s):

Jéssica Aparecida Alves ◽

Fariza Abrão ◽

Thaís da Silva Moraes ◽

Jaqueline Lopes Damasceno ◽

Marcos Fernando dos Santos Moraes ◽

...

Keyword(s):

Minimum Inhibitory Concentration ◽

Plant Extracts ◽

Concentration Index ◽

Antimycobacterial Activity ◽

Synergistic Action ◽

Copaifera Langsdorffii

Aim: This paper reports on the antimycobacterial activity of the oleoresins and extracts obtained from Copaifera spp. Materials & methods: The minimum inhibitory concentration (MIC) and fractional inhibitory concentration index techniques helped to evaluate the effect of these oleoresins and extracts against six strains of mycobacteria that cause tuberculosis. Results & conclusion: Among the assayed oleoresins and plant extracts, the Copaifera langsdorffii, Copaifera duckei, Copaifera reticulata and Copaifera trapezifolia oleoresins provided the lowest MIC values against some of the tested strains. The combination of Copaifera spp. samples with isoniazid did not evidence any synergistic action. Some Copaifera spp. oleoresins may represent a future source for the discovery of new antimycobacterial drugs due to their low MIC values.

Prevention of Pseudomonas aeruginosa Biofilm Formation on Soft Contact Lenses by Allium sativum Fermented Extract (BGE) and Cannabinol Oil Extract (CBD)

Antibiotics ◽

10.3390/antibiotics8040258 ◽

2019 ◽

Vol 8 (4) ◽

pp. 258 ◽

Cited By ~ 3

Author(s):

Valeria Di Onofrio ◽

Renato Gesuele ◽

Angela Maione ◽

Giorgio Liguori ◽

Renato Liguori ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Biofilm Formation ◽

Concentration Index ◽

Contact Lenses ◽

Clinical Strain ◽

Soft Contact ◽

Soft Contact Lenses

Two natural mixtures, Allium sativum fermented extract (BGE) and cannabinol oil extract (CBD), were assessed for their ability to inhibit and remove Pseudomonas aeruginosa biofilms on soft contact lenses in comparison to a multipurpose Soft Contact Lens-care solution present on the Italian market. Pseudomonas aeruginosa (ATCC 9027 strain) and Pseudomonas aeruginosa clinical strains isolated from ocular swabs were tested. Quantification of the biofilm was done using the microtiter plate assay and the fractional inhibitory concentration index was calculated. Both forms of Pseudomonas aeruginosa generated biofilms. BGE at minimal inhibitory concentration (MIC) showed inhibition percentages higher than 55% for both strains, and CBD inhibited biofilm formation by about 70%. The care solution at MIC inhibited biofilm formation by about 50% for both strains tested. The effect of BGE on the eradication of the microbial biofilm on soft contact lenses at MIC was 45% eradication for P. aeruginosa ATCC 9027 and 36% for P. aeruginosa clinical strain. For CBD, we observed 24% biofilm eradication for both strains. For the care solution, the eradication MICs were 43% eradication for P. aeruginosa ATCC 9027 and 41% for P. aeruginosa clinical strain. It was observed that both the test soft contact lenses solution/BGE (fractional inhibitory concentration index: 0.450) and the test soft contact lenses solution/CBD (fractional inhibitory concentration index: 0.153) combinations exhibited synergistic antibiofilm activity against most of the studied bacteria. The study showed that BGE and CBD have good effect on inhibition of biofilm formation and removal of preformed biofilms, which makes them promising agents that could be exploited to develop more effective care solutions.

In VitroEvaluation of the Type of Interaction Obtained by the Combination of Terbinafine and Itraconazole, Voriconazole, or Amphotericin B against Dematiaceous Molds

10.1128/aac.01015-10 ◽

2011 ◽

Vol 55 (9) ◽

pp. 4485-4487 ◽

Cited By ~ 10

Author(s):

Fernanda Simas Corrêa Biancalana ◽

Luzia Lyra ◽

Angélica Zaninelli Schreiber

Keyword(s):

Amphotericin B ◽

Alternative Treatment ◽

Concentration Index ◽

Drug Combinations ◽

Single Drug ◽

Microdilution Method

ABSTRACTIn vitroassociations using the checkerboard microdilution method indicated lower MIC ranges and MIC median values for each drug (terbinafine, itraconazole, voriconazole, and amphotericin B) in association than those obtained for each single drug. Fractional inhibitory concentration index (FIC) results showed 100% synergism in the association of terbinafine with voriconazole, 96.5% in the association of terbinafine with amphotericin B, and 75.9% in the association of terbinafine with itraconazole. Drug combinations may be useful for treatment of dematiaceous mold infections as an alternative treatment to enhance the effectiveness of each drug.

In Vitro Assessment of the Efficacy of Erythromycin in Combination with Oxytetracycline or Spectinomycin against Pasteurella Haemolytica

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063878900100404 ◽

1989 ◽

Vol 1 (4) ◽

pp. 299-304 ◽

Cited By ~ 8

Author(s):

George E. Burrows ◽

Patty Ewing

Keyword(s):

Concentration Index ◽

Mechanisms Of Action ◽

Pasteurella Haemolytica ◽

Disease Treatment ◽

Tissue Concentrations ◽

In Vitro Assessment

The effects of combining erythromycin (Ery) with oxytetracycline (Oxy) or spectinomycin (Sp) on Pasteurella haemolytica were evaluated in vitro using the chessboard (checkerboard) technique. These combinations were selected because all are drugs widely used in bovine respiratory disease treatment, and they represent possible sequential or complementary mechanisms of action. Using the recommended breakpoints of >4 μg/ml for Ery, 16 μl for Oxy, and 32 μl for Sp, of the 33 P. haemolytica isolates, 32 were resistant to Oxy, 27 to Sp, and 14 to Ery. Based on the fractional inhibitory concentration index, Ery and Oxy in combination were synergistic or additive against 32 of 33 isolates. The combination of Ery and Sp was synergistic or additive against 27 of 33 isolates. No instances of antagonism were seen. When the effects were considered within the context of therapeutically achievable serum/tissue concentrations, the effects of Ery and Oxy in combination were only marginal. Thus, against P. haemolytica isolates, Ery and Sp appeared to represent an effective antimicrobial combination, whereas Ery and Oxy were only of marginal efficacy as a combination.