Ginseng aqueous extract attenuates the production of virulence factors, stimulates twitching and adhesion, and eradicates biofilms of Pseudomonas aeruginosa

2011 ◽  
Vol 89 (6) ◽  
pp. 419-427 ◽  
Author(s):  
Misagh Alipour ◽  
Abdelwahab Omri ◽  
Zacharias E. Suntres
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Aqueous Extract ◽  
North American ◽  
American Ginseng ◽  
Antimicrobial Activities ◽  
Live Cells ◽  
Dilution Method ◽  
Agar Dilution Method

This study was carried out to examine the antimicrobial activity of the aqueous extract of Panax quinquefolius from North American ginseng (NAGE) root against Pseudomonas aeruginosa . The minimum inhibitory concentrations of reference and clinical isolates of Pseudomonas aeruginosa were measured by a standard agar-dilution method. At subinhibitory NAGE concentrations, the secretion of virulence factors, motility on agar, and adhesion to 96-well microplates were studied on the nonmucoid Pseudomonas aeruginosa O1 strain. At suprainhibitory concentrations, the activity of NAGE against mature biofilm complexes formed in the Calgary Biofilm Device and the Stovall flow cell were assessed. NAGE possessed an antibacterial activity against all the Pseudomonas aeruginosa strains at 1.25%–2.5% w/v. NAGE also significantly attenuated pyocyanin, pyoverdine, and lipase concentrations, stimulated twitching, and attenuated swarming and swimming motility. At 1.25% w/v, NAGE augmented adhesion, and at 5% w/v detached 1-day-old biofilms in microplates. The extract also eradicated 6-day-old mature biofilms (5% w/v), and fluorescence microscopy displayed a reduction of live cells and biofilm complexes compared with nontreated biofilms. These data suggest that the aqueous extract from North American ginseng possesses antimicrobial activities in vitro.

scholarly journals In vitro minocycline activity on superinfecting microorganisms isolated from chronic periodontitis patients

2006 ◽  
Vol 20 (3) ◽  
pp. 202-206 ◽  
Author(s):  
Luciana Fernandes de Oliveira ◽  
Antonio Olavo Cardoso Jorge ◽  
Silvana Soléo Ferreira dos Santos
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Chronic Periodontitis ◽  
Periodontal Pocket ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Periodontal Pathogens ◽  
Candida Spp ◽  
Systemic Antibiotic Therapy ◽  
Staphylococcus Spp

Chronic periodontitis is the most common type of periodontitis and it is associated with various species of microorganisms. Enteric rods, Pseudomonas, Staphyloccocus and Candida have been retrieved from periodontal pockets of patients with chronic periodontitis and correlated to cases of superinfection. Local or systemic antibiotic therapy is indicated to reinforce the effects of the conventional mechanical therapy. Minocycline has been suggested as one of the most effective drugs against periodontal pathogens. The aim of this work was to evaluate the minimal inhibitory concentration (MIC) of minocycline on superinfecting microorganisms isolated from the periodontal pocket and the oral cavity of individuals with chronic periodontitis. Isolates of Enterobacteriaceae (n = 25), Staphylococcus spp. (n = 25), Pseudomonas aeruginosa (n = 9) and Candida spp. (n = 25) were included in the study. Minimal inhibitory concentrations (MIC) of minocycline were determined using the Müeller-Hinton agar dilution method. Staphylococcus spp. isolates were the most sensitive to minocycline with a MIC of 8 µg/mL, followed by Enterobacteriaceae with a MIC of 16 µg/mL. The concentration of 16 µg/mL inhibited 96% of Candida spp. isolates. The MIC for 88.8% of the isolates of Pseudomonas aeruginosa was 128 µg/mL. A concentration of 1,000 µg/mL was not enough to inhibit 100% of the tested isolates.

scholarly journals In Vitro Activities of a New Des-Fluoro(6) Quinolone, Garenoxacin, against Clinical Anaerobic Bacteria

2003 ◽  
Vol 47 (11) ◽  
pp. 3667-3671 ◽  
Author(s):  
A. Liebetrau ◽  
A. C. Rodloff ◽  
J. Behra-Miellet ◽  
L. Dubreuil
Keyword(s):  
Clostridium Difficile ◽  
Anaerobic Bacteria ◽  
Bacteroides Fragilis ◽  
Antimicrobial Activities ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Gram Positive ◽  
Agar Dilution ◽  
Gram Positive Cocci

ABSTRACT The antimicrobial activities of garenoxacin and eight other antibiotics against 641 anaerobic isolates were evaluated with the NCCLS agar dilution method. Overall, the MICs of garenoxacin for 50 and 90% of the strains tested (in micrograms per milliliter) were as follows: Bacteroides fragilis group, 0.5 and 2; Prevotella spp., 0.25 and 2; Fusobacterium spp., 0.25 and 0.5; Porphyromonas spp., 0.125 and 0.25; Bilophila wadsworthia, 0.5 and 1; Veillonella spp., 0.25 and 0.5; Clostridium spp., 0.25 and 1; Clostridium difficile, 2 and >64; Bifidobacterium spp., 1 and 2; Eggerthella lenta, 0.25 and 1; Propionibacterium spp., 0.5 and 0.5; gram-positive cocci, 0.125 and 0.25.

scholarly journals In vitro efficacy of synergistic antibiotic combinations in imipenem resistant Pseudomonas aeruginosa strains

2017 ◽  
Vol 9 (1) ◽  
pp. 3-8
Author(s):  
Aleya Farzana ◽  
S. M. Shamsuzzaman
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Considerable Proportion ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
New Antibiotics

The increase in antibiotic resistance coincided with the decline in production of new antibiotics. Combination antibiotic treatment is preferred in nosocomial infections caused by multidrug resistant Pseudomonas aeruginosa. In vitro synergism test by agar dilution method were used to choose the combinations which might be used in clinic. The aim of this study was to investigate the synergistic efficacy of antibiotic combinations in imipenem resistant P. aeruginosa strains. Carbapenem resistance (imipenem and meropenem) wasdetermined by disk diffusion method. Among isolated P. aeruginosa 44.9% were cabapenem resistant. The MIC of drugs among 25 imipenem resistant isolates ranged from >_ 256 mg/L to <_ 8 mg/L for imipenem, >_ 1024 mg/L to <_ 64 mg/L for ceftriaxone, >_ 256 mg/L to <_ 8 mg/L for amikacin, >_ 16 mg/L to <_ 2 mg/L for colistin, >_ 512 mg/L to <_ 16 mg/L for piperacillin/tazobactam. Among antibiotic combinations, piperacillin /tazobactam- amikacin was most effective with 80% synergism next to which was imipenem-amikacin with 60% synergism, then imipenem-colistin with 50% synergism, imipenem-ceftriaxone with 30% synergism. Only one combination (piperacillin/tazobactum -imipenem showed 20% antagonism. All these combinations had considerable proportion of additive effect which is also desirable for these multi drug resistant isolates.Bangladesh J Med Microbiol 2015; 9 (1): 3-8

scholarly journals Comparative Antimicrobial Activities of the Newly Synthesized Quinolone WQ-3034, Levofloxacin, Sparfloxacin, and Ciprofloxacin against Mycobacterium tuberculosis andMycobacterium avium Complex

2000 ◽  
Vol 44 (2) ◽  
pp. 283-286 ◽  
Author(s):  
Haruaki Tomioka ◽  
Katsumasa Sato ◽  
Hiroko Kajitani ◽  
Tatsuya Akaki ◽  
Shinji Shishido
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Cell Line ◽  
Antimicrobial Activities ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Type Ii ◽  
In Vitro Activity ◽  
Alveolar Cell ◽  
Agar Dilution

ABSTRACT WQ-3034 is a newly synthesized acidic fluoroquinolone. We assessed its in vitro activity against Mycobacterium tuberculosisand M. avium complex using levofloxacin (LVFX), ciprofloxacin (CPFX), sparfloxacin (SPFX), and KRM-1648 (KRM) as reference drugs. The MICs of these agents were determined by the agar dilution method with 7H11 medium. The MICs at which 50 and 90% of the test strains were inhibited (MIC50s, and MIC90s, respectively) for the test quinolones for rifampin (RMP)-susceptible M. tuberculosis strains were in the order SPFX < LVFX ≦ WQ-3034 ≦ CPFX, while those for RMP-resistant M. tuberculosis strains were in the order SPFX ≦ WQ-3034 ≦ LVFX < CPFX. The MICs of KRM for RMP-susceptible M. tuberculosis were much lower than those of the test quinolones, while the MIC90 of KRM for RMP-resistant M. tuberculosis strains was higher than those of the quinolones. The MIC50s and MIC90s of the test drugs for M. avium were in the order KRM < SPFX < CPFX ≦ WQ-3034 ≦ LVFX, while those forM. intracellulare were in the order KRM < SPFX < WQ-3034 ≒ LVFX ≦ CPFX. Next, we compared the antimicrobial activities of the test drugs against M. tuberculosisorganisms residing in cells of the Mono Mac 6 macrophage (Mφ)-like cell line (MM6-Mφs) and of the A-549 type II alveolar cell line (A-549 cells). When drugs were added at the concentration that achieves the maximum concentration in blood, progressive killing or inhibition of the M. tuberculosis organisms residing in MM6-Mφs and A-549 cells was observed in the order KRM > SPFX ≧ LVFX > WQ-3034 > CPFX. The efficacies of all quinolones against intracellular M. tuberculosis organisms were significantly lower in A-549 cells than in MM6-Mφs. WQ-3034 at the MIC caused more marked growth inhibition of intramacrophage M. tuberculosis than did LVFX. These findings indicate that the in vitro anti-M. tuberculosis activity of WQ-3034 is greater than that of CPFX and is comparable to that of LVFX.

scholarly journals In-vitro Screening of Antimicrobial Activities of Ocimum gratissimum on Clinical Isolates

2019 ◽  
pp. 1-7
Author(s):  
Ifeanyi Onyema Oshim ◽  
Evelyn Ukamaka Urama ◽  
Oluwayemisi Odeyemi ◽  
Augustina Nkechi Olise ◽  
Sunday Odeyemi
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Ethanolic Extract ◽  
Antimicrobial Activities ◽  
Negative Control ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Ocimum Gratissimum

This study was undertaken to evaluate  the antimicrobial activities of crude  ethanol and methanol extracts of the leaves of Ocimum gratissimum L. (scent leaf) on Escherichia coli, Klebsiella  pneumoniae, Pseudomonas aeruginosa, Staphylococcus auerus and Candida albicans.The antimicrobial activities were carried out using  agar well diffusion method. The Minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) of the plant extracts on the test isolates were determined by the agar dilution method. Ciprofloxacin and fluconazole (positive controls) were used in comparison with crude extract of O. gratissimum leaves and also, Dimethyl sulfoxide (DMSO) was used as the negative control. The ethanolic extract of O. gratissimum showed antibacterial activity with the mean inhibitory zone diameter of 3 -7mm against S. auerus, 2 mm against E. coli, 2 – 12 mm against K. pneumoniae, 2 mm against P.aeruginosa. Ethanol and methanol crude extracts of O. gratissimum leaves   showed no effect on   C.albicans. O. gratissimum extracts showed the lower   antimicrobial activity than the commercially available antibiotics (ciprofloxacin and fluconazole). The minimum Inhibitory Concentration and Minimum Bactericidal Concentration of the extracts on the test organisms also increased in the following order; methanol < ethanol. Hence, this   extract could   only serve   as antibacterial agent in the management of bacterial infection because it has no antifungal activities on Candida isolates used in this study.

scholarly journals Doripenem versus Pseudomonas aeruginosa In Vitro: Activity against Characterized Isolates, Mutants, and Transconjugants and Resistance Selection Potential

2004 ◽  
Vol 48 (8) ◽  
pp. 3086-3092 ◽  
Author(s):  
Shazad Mushtaq ◽  
Yigong Ge ◽  
David M. Livermore
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Clinical Laboratory ◽  
Acquired Resistance ◽  
Single Step ◽  
Cross Resistance ◽  
National Committee ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Resistant Mutants

ABSTRACT Doripenem is a broad-spectrum parenteral carbapenem under clinical development in Japan and North America. Its activities against (i) Pseudomonas aeruginosa isolates with graded levels of intrinsic efflux-type resistance, (ii) mutants with various combinations of AmpC and OprD expression, (iii) PU21 transconjugants with class A and D β-lactamases, and (iv) P. aeruginosa isolates with metallo-β-lactamases were tested by the agar dilution method of the National Committee for Clinical Laboratory Standards. Selection of resistant P. aeruginosa mutants was investigated in single- and multistep procedures. Doripenem MICs for isolates without acquired resistance mostly were 0.12 to 0.5 μg/ml, whereas meropenem MICs were 0.25 to 0.5 μg/ml and imipenem MICs were 1 to 2 μg/ml. The MICs of doripenem, meropenem, ertapenem, and noncarbapenems for isolates with increased efflux-type resistance were elevated, whereas the MICs of imipenem were less affected. The MICs of doripenem were increased by the loss of OprD but not by derepression of AmpC; nevertheless, and as with other carbapenems, the impermeability-determined resistance caused by the loss of OprD corequired AmpC activity and was lost in OprD− mutants also lacking AmpC. The TEM, PSE, PER, and OXA enzymes did not significantly protect P. aeruginosa PU21 against the activity of doripenem, whereas MICs of ≥16 μg/ml were seen for clinical isolates with VIM and IMP metallo-β-lactamases. Resistant mutants seemed to be harder to select with doripenem than with other carbapenems (or noncarbapenems), and the fold increases in the MICs were smaller for the resistant mutants. Single-step doripenem mutants were mostly resistant only to carbapenems and had lost OprD; multistep mutants had broader resistance, implying the presence of additional mechanisms, putatively including up-regulated efflux. Most mutants selected with aminoglycosides and quinolones had little or no cross-resistance to carbapenems, including doripenem.

Synthesis and Biological Evaluation of 3-cyano-4H-chromene Derivatives Bearing Carbamate Functionality

2019 ◽  
Vol 15 (3) ◽  
pp. 257-264 ◽  
Author(s):  
Fatma Boukattaya ◽  
Amal Daoud ◽  
Fabien Boeda ◽  
Morwenna S.M. Pearson-Long ◽  
Néji Gharsallah ◽  
...  
Keyword(s):  
Antimicrobial Activities ◽  
Biological Evaluation ◽  
Grignard Reagents ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Significant Activity ◽  
Anticancer Activities ◽  
Gram Positive Bacteria ◽  
Agar Dilution

Background: 2-Aminochromene derivatives display important pharmacological properties, including mainly antibiotic and anticancer activities. Objective: The study aims to synthesize new chromene derivatives via a new approach using Grignard reagents, for the evaluation of their antibiotic and antifungal properties. Method: A series of novel 3-cyano-4-aminochromene derivatives bearing alkyl substituents at the 4-position was prepared for biological evaluation. Results: These compounds were obtained by the addition of various Grignard reagents into Nethoxycarbonyl- 3-cyanoiminocoumarines in moderate to good yields (72-96%). The reaction is completely regioselective. The new chromene derivatives were screened for their in vitro antimicrobial activities against a panel of six bacterial and three fungal strains using agar dilution method. Conclusion: The antibacterial activity of the chromene derivatives was more pronounced on Gram-positive bacteria than on Gram-negative bacteria with a significant activity observed against Staphylococcus aureus. An interesting antifungal activity against Fusarium sp. and Fusarium oxysporum was also noticed.

scholarly journals In Vitro and In Vivo Activities of Fluoroquinolones against Aeromonas hydrophila

2003 ◽  
Vol 47 (7) ◽  
pp. 2217-2222 ◽  
Author(s):  
Wen-Chien Ko ◽  
Shyh-Ren Chiang ◽  
Hsin-Chun Lee ◽  
Hung-Jen Tang ◽  
Yin-Yi Wang ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Treated Group ◽  
Antimicrobial Activities ◽  
Inhibitory Effect ◽  
Rank Test ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Log Rank Test

ABSTRACT Aeromonas hydrophila, an uncommon human pathogen, can cause invasive infections in immunocompromised individuals. As the fluoroquinolones have been shown to be active in vitro against mesophilic aeromonads and clinical experience with the use of fluoroquinolones to treat aeromonads infections is limited, the antimicrobial activities of five selected drugs (ciprofloxacin, gatifloxacin, levofloxacin, lomefloxacin, and moxifloxacin) against A. hydrophila were studied in vitro and in mice. The MICs of the fluoroquinolones (except lomefloxacin), cefotaxime, and minocycline for 90% of 64 clinical isolates of A. hydrophila tested by the agar dilution method were ≤1 μg/ml. With a clinical cefotaxime-resistant strain, Ah 2743, in an in vitro time-kill study, at an inoculum of 7 × 105 CFU/ml incubated with fluoroquinolones, cefotaxime, or minocycline at concentrations equal to twice the MICs, the inhibitory effect lasted for less than 6 h and regrowth occurred thereafter. In an animal model with female BALB/c mice intraperitoneally infected with an inoculum of 1.1 × 107 CFU of Ah 2743, more mice in the ciprofloxacin-treated group survived (72.2%) than in the cefotaxime-, minocycline-, or cefotaxime-minocycline-treated group (P < 0.00001, log rank test). However, there were similar fatality rates, ranging from 71.4 to 87.5%, among mice treated with any of five fluoroquinolones. With a larger inoculum, 4.9 × 107 CFU, mice in the ciprofloxacin-treated group survived longer than those in the minocycline-, cefotaxime-, or cefotaxime-minocycline-treated group (30 h versus 18, 12, and 12 h, respectively [P < 0.002, log rank test]). However, in mice infected with cefotaxime-susceptible Ah 2556, ciprofloxacin was as effective as cefotaxime-minocycline. Thus, our results suggest that ciprofloxacin is at least as effective as cefotaxime-minocycline against murine A. hydrophila infections, which warrants clinical studies to delineate its role in human infections.

scholarly journals e-Pharmacophore model-guided design of potential DprE1 inhibitors: synthesis, in vitro antitubercular assay and molecular modelling studies

2021 ◽  
Author(s):  
Avinash Kumar ◽  
Revathi Rajappan ◽  
Suvarna G. Kini ◽  
Ekta Rathi ◽  
Sriram Dharmarajan ◽  
...  
Keyword(s):  
Pharmacophore Model ◽  
Antitubercular Activity ◽  
Stable Complex ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Standard Drug ◽  
Docking Score ◽  
Mycobacterium Tuberculosis H37rv ◽  
Cytotoxicity Studies

AbstractTuberculosis continues to wreak havoc worldwide and caused around 1.4 million deaths in 2019. Hence, in our pursuit of developing novel antitubercular compounds, we are reporting the e-Pharmacophore-based design of DprE1 (decaprenylphosphoryl-ribose 2′-oxidase) inhibitors. In the present work, we have developed a four-feature e-Pharmacophore model based on the receptor–ligand cavity of DprE1 protein (PDB ID 4P8C) and mapped our previous reported library of compounds against it. The compounds were ranked on phase screen score, and the insights obtained from their alignment were used to design some novel compounds. The designed compounds were docked with DprE1 protein in extra-precision mode using Glide module of Maestro, Schrodinger. Some derivatives like B1, B2, B4, B5 and B12 showed comparable docking score (docking score > − 6.0) with respect to the co-crystallized ligand. The designed compounds were synthesized and characterized. In vitro antitubercular activity was carried out on Mycobacterium tuberculosis H37Rv (ATCC27294) strain using the agar dilution method, and minimum inhibitory concentration (MIC) was determined. The compound B12 showed a MIC value of 1.56 μg/ml which was better than the standard drug ethambutol (3.125 μg/ml). Compounds B7 and B11 were found to be equipotent with ethambutol. Cytotoxicity studies against Vero cell lines proved that these compounds were non-cytotoxic. Molecular dynamic simulation study also suggests that compound B12 will form a stable complex with DprE1 protein and will show the crucial H-bond interaction with LYS418 residue. Further in vitro enzyme inhibition studies are required to validate these findings.

scholarly journals The Impact of an Efflux Pump Inhibitor on the Activity of Free and Liposomal Antibiotics against Pseudomonas aeruginosa

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 577
Author(s):  
Douweh Leyla Gbian ◽  
Abdelwahab Omri
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Antimicrobial Activities ◽  
Dilution Method ◽  
Efflux Pump Inhibitor ◽  
Signal Production ◽  
Lung Infections ◽  
The Impact ◽  
Microbroth Dilution

The eradication of Pseudomonas aeruginosa in cystic fibrosis patients has become continuously difficult due to its increased resistance to treatments. This study assessed the efficacy of free and liposomal gentamicin and erythromycin, combined with Phenylalanine arginine beta-naphthylamide (PABN), a broad-spectrum efflux pump inhibitor, against P. aeruginosa isolates. Liposomes were prepared and characterized for their sizes and encapsulation efficiencies. The antimicrobial activities of formulations were determined by the microbroth dilution method. Their activity on P. aeruginosa biofilms was assessed, and the effect of sub-inhibitory concentrations on bacterial virulence factors, quorum sensing (QS) signals and bacterial motility was also evaluated. The average diameters of liposomes were 562.67 ± 33.74 nm for gentamicin and 3086.35 ± 553.95 nm for erythromycin, with encapsulation efficiencies of 13.89 ± 1.54% and 51.58 ± 2.84%, respectively. Liposomes and PABN combinations potentiated antibiotics by reducing minimum inhibitory and bactericidal concentrations by 4–32 fold overall. The formulations significantly inhibited biofilm formation and differentially attenuated virulence factor production as well as motility. Unexpectedly, QS signal production was not affected by treatments. Taken together, the results indicate that PABN shows potential as an adjuvant of liposomal macrolides and aminoglycosides in the management of lung infections in cystic fibrosis patients.

Sign in / Sign up

Export Citation Format

Share Document