scholarly journals COMBINATORIAL EFFECT OF D-AMINOACIDS AND TETRACYCLINE AGAINST PSEUDOMONAS AERUGINOSA BIOFILM

2016 ◽  
Vol 8 (11) ◽  
pp. 216
Author(s):  
H. Jayalekshmi ◽  
C. Harikrishnan ◽  
Sajin Sali ◽  
N. Kaushik ◽  
Norin Mary G. Victus ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Wound Dressing ◽  
Ex Vivo ◽  
Multidrug Resistant ◽  
Antibiofilm Activity ◽  
Porcine Skin ◽  
Clinical Strains ◽  
Microtitre Plate Assay

Objective: The present study attempted to evaluate the anti-biofilm activity of D-amino acids (D-AAs) on Pseudomonas aeruginosa and determine if the combination of D-AAs with tetracycline enhances the anti-biofilm activity in vitro and ex vivo.Methods: Different D-AAs were tested for antibiofilm activity against wild type P. aeruginosa PAO1 and two multidrug resistant P. aeruginosa clinical strains in the presence of sub inhibitory concentrations of tetracycline using crystal violet microtitre plate assay. Results were further validated using in vitro wound dressing and ex vivo porcine skin models followed by cytotoxicity and hemocompatibility studies.Results: D-tryptophan (5 mmol) showed 61 % reduction in biofilm formation of P. aeruginosa. Interestingly combinatorial effect of 5 mmol D-tryptophan and 0.5 minimum inhibitory concentration (MIC) (7.5µg/ml) tetracycline showed 90% reduction in biofilm formation. 5 mmol D-methionine shows 28 % reduction and combination with tetracycline shows 41% reduction in biofilm formation of P. aeruginosa. D-leucine and D-tyrosine alone or in combination with tetracycline did not show significant anti-biofilm activity. D tryptophan-tetracycline combination could reduce 80 % and 77 % reduction in biofilm formation in two multi drug resistant P. aeruginosa clinical strains. D-tryptophan-tetracycline-combination could also reduce 76% and 66% reduction in biofilm formation in wound dressing model and porcine skin explant respectively. The cytotoxicity and hemocompatibility studies did not show significant toxicity when this combination was used.Conclusion: The results established the potential therapeutic application of D-tryptophan alone or in combination with tetracycline for treating biofilm associated clinical problems caused by P. aeruginosa.

scholarly journals Inhibitory effect of propafenone derivatives on pseudomonas aeruginosa biofilm and pyocyanin production

2020 ◽  
Vol 148 (3-4) ◽  
pp. 196-202
Author(s):  
Snjezana Petrovic ◽  
Jasmina Basic ◽  
Zoran Mandinic ◽  
Dragana Bozic ◽  
Marina Milenkovic ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Laboratory Strain ◽  
Inhibitory Effect ◽  
Negative Control ◽  
Clinical Strains ◽  
Control Value ◽  
Essential Components ◽  
Pyocyanin Production

Introduction/Objective. Biofilm and pyocyanin production are essential components of Pseudomonas aeruginosa virulence and antibiotic resistance. Our objective was to examine inhibitory effect of synthetized propafenone derivatives 3-(2-Fluorophenyl)- 1-(2- (2-hydroxy-3-propylamino-propoxy)-phenyl)-propan-1-one hydrochloride (5OF) and3-(2- Trifluoromethyl-phenyl)-1-(2-(2-hydroxy-3-propylamino-propoxy)-phenyl)-propan-1-one hydrochloride (5CF3) on biofilm and pyocyanin in Pseudomonas aeruginosa clinical strains. Methods. Effects were tested on nine clinical isolates and one control laboratory strain of P. aeruginosa. In vitro analysis of biofilm growing was performed by incubating bacteria (0.5 McFarland) with 5OF and 5CF3 (500?31.2 ?g/ml) and measuring optical density (OD) at 570 nm. Bacteria in medium without compounds were positive control. Blank medium (an uninoculated medium without test compounds) was used as negative control. Pyocyanin production was estimated by OD at 520 nm, after bacteria incubated with 5CF3 and 5OF (250 and 500 ?g/ml), treated with chloroform, and chloroform layer mixed with HCl. Results. A total of 500 ?g/ml of 5OF and 5CF3 completely inhibited biofilm formation in 10/10 and 4/10 strains, respectively. A total of 250 ?g/ml of 5OF and 5CF3 strongly inhibited biofilm formation in 7/10 strains, while inhibition with 125 ?g/ml of 5OF and 5CF3 was moderate. Lower concentrations had almost no effect on biofilm production. Pyocyanin production was reduced to less than 40% of the control value in 6/9, and less than 50% of the control in 7/9 strains with 500 ?g/ml of 5OF and 5CF3, respectively. At 250 ?g/ml 5OF and 5CF3, most strains had pyocyanin production above 50% of the control value. Conclusion. Synthetized propafenone derivatives, 5OF and 5CF3, inhibited biofilms and pyocyanin production of Pseudomonas aeruginosa clinical strains. Presented results suggest that propafenone derivatives are potential lead-compounds for synthesis of novel antipseudomonal drugs.

scholarly journals Antimicrobial and Antibiofilm Activity against Staphylococcus aureus of Opuntia ficus-indica (L.) Mill. Cladode Polyphenolic Extracts

Antioxidants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 117 ◽  
Author(s):  
Federica Blando ◽  
Rossella Russo ◽  
Carmine Negro ◽  
Luigi De Bellis ◽  
Stefania Frassinetti
Keyword(s):  
Staphylococcus Aureus ◽  
Antioxidant Activity ◽  
Antioxidant Capacity ◽  
Biofilm Formation ◽  
Ex Vivo ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Total Phenolic ◽  
Antibiofilm Activity ◽  
Opuntia Ficus Indica

Plant extracts are a rich source of natural compounds with antimicrobial properties, which are able to prevent, at some extent, the growth of foodborne pathogens. The aim of this study was to investigate the potential of polyphenolic extracts from cladodes of Opuntia ficus-indica (L.) Mill. to inhibit the growth of some enterobacteria and the biofilm formation by Staphylococcus aureus. Opuntia ficus-indica cladodes at two stages of development were analysed for total phenolic content and antioxidant activity by Oxygen Radical Absorbance Capacity (ORAC) and Trolox equivalent antioxidant capacity (TEAC) (in vitro assays) and by cellular antioxidant activity in red blood cells (CAA-RBC) (ex vivo assay). The Liquid Chromatography Time-of-Flight Mass Spectrometry (LC/MS–TOF) analysis of the polyphenolic extracts revealed high levels of piscidic acid, eucomic acid, isorhamnetin derivatives and rutin, particularly in the immature cladode extracts. Opuntia cladodes extracts showed a remarkable antioxidant activity (in vitro and ex vivo), a selective inhibition of the growth of Gram-positive bacteria, and an inhibition of Staphylococcus aureus biofilm formation. Our results suggest and confirm that Opuntia ficus-indica cladode extracts could be employed as functional food, due to the high polyphenolic content and antioxidant capacity, and used as natural additive for food process control and food safety.

Phage therapy to control multidrug-resistant Pseudomonas aeruginosa skin infections: in vitro and ex vivo experiments

2012 ◽  
Vol 31 (11) ◽  
pp. 3241-3249 ◽  
Author(s):  
A. Vieira ◽  
Y. J. Silva ◽  
Â. Cunha ◽  
N. C. M. Gomes ◽  
H.-W. Ackermann ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Phage Therapy ◽  
Ex Vivo ◽  
Multidrug Resistant ◽  
Skin Infections

scholarly journals Clinically Relevant Concentrations of Polymyxin B and Meropenem Synergistically Kill Multidrug-Resistant Pseudomonas aeruginosa and Minimize Biofilm Formation

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 405
Author(s):  
Hasini Wickremasinghe ◽  
Heidi H. Yu ◽  
Mohammad A. K. Azad ◽  
Jinxin Zhao ◽  
Phillip J. Bergen ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Respiratory Infections ◽  
Population Analysis ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Polymyxin B ◽  
Multidrug Resistant ◽  
Bacterial Killing

The emergence of antibiotic resistance has severely impaired the treatment of chronic respiratory infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa. Since the reintroduction of polymyxins as a last-line therapy against MDR Gram-negative bacteria, resistance to its monotherapy and recurrent infections continue to be reported and synergistic antibiotic combinations have been investigated. In this study, comprehensive in vitro microbiological evaluations including synergy panel screening, population analysis profiling, time-kill kinetics, anti-biofilm formation and membrane damage analysis studies were conducted to evaluate the combination of polymyxin B and meropenem against biofilm-producing, polymyxin-resistant MDR P. aeruginosa. Two phylogenetically unrelated MDR P. aeruginosa strains, FADDI-PA060 (MIC of polymyxin B [MICpolymyxin B], 64 mg/L; MICmeropenem, 64 mg/L) and FADDI-PA107 (MICpolymyxin B, 32 mg/L; MICmeropenem, 4 mg/L) were investigated. Genome sequencing identified 57 (FADDI-PA060) and 50 (FADDI-PA107) genes predicted to confer resistance to a variety of antimicrobials, as well as multiple virulence factors in each strain. The presence of resistance genes to a particular antibiotic class generally aligned with MIC results. For both strains, all monotherapies of polymyxin B failed with substantial regrowth and biofilm formation. The combination of polymyxin B (16 mg/L)/meropenem (16 mg/L) was most effective, enhancing initial bacterial killing of FADDI-PA060 by ~3 log10 CFU/mL, followed by a prolonged inhibition of regrowth for up to 24 h with a significant reduction in biofilm formation (* p < 0.05). Membrane integrity studies revealed a substantial increase in membrane depolarization and membrane permeability in the surviving cells. Against FADDI-PA107, planktonic and biofilm bacteria were completely eradicated. In summary, the combination of polymyxin B and meropenem demonstrated synergistic bacterial killing while reinstating the efficacy of two previously ineffective antibiotics against difficult-to-treat polymyxin-resistant MDR P. aeruginosa.

scholarly journals In vitro biofilm formation by multidrug resistant clinical isolates of Pseudomonas aeruginosa

2018 ◽  
Vol 4 (1) ◽  
pp. 105-116
Author(s):  
Sohana Al Sanjee ◽  
Md Mahamudul Hassan ◽  
MA Manchur
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Test Tube ◽  
Microtitre Plate ◽  
Microbial Identification ◽  
Antibiotic Susceptibility Test ◽  
Microtitre Plate Assay ◽  
Mar Index ◽  
Effective Group

In this study, 15 isolates of Pseudomonas aeruginosa were recovered in Cetrimide agar medium from aseptically collected swab samples. Antibiotic susceptibility test revealed highest resistance against Rifampicin (100%) followed by Penicillin (80%), Erythromycin (73.33%), Cephalosporin group (13.33-60%) and Aminoglycoside group (26.67%). The most effective group of antibiotic was Carbapenem with 6.67% resistance. Among 15 isolates, 3 were having highest Multiple Antibiotic Resistance (MAR) index were identified as Pseudomonas aeruginosa (P1, P2 and P3) by API®20NE microbial identification kit. Minimum inhibitory concentration (MIC) of the isolates P1, P2 and P3 was 3.05μg/mL, 0.76μg/mL and 3.05μg/mL for Meropenem whereas for Ceftriaxone it was 12.207μg/mL, 12.207μg/mL and 781.25μg/mL, respectively. Minimum bactericidal concentration (MBC) of Meropenem and Ceftriaxone was same for the isolates P1 and P2 i.e., 48.83μg/mL and 195.313μg/mL, respectively but in case of P3 it was 781.25μg/mL for both antibiotics. In case of 70% ethanol, the MIC and MBC was 1:4 dilutions (for isolate P3, MBC was 1:2 dilutions) whereas for Savlon®, MIC and MBC was 1% and 2% solution, respectively. All of the three isolates were biofilm former according to test tube assay and microtitre plate assay whereas modified congo red agar assay indicated only one isolate as biofilm former. The results suggest that post-operative wound infection may serve as a reservoir for multidrug resistant biofilm forming P. aeruginosa which may complicate the treatment regime unless proper treatment ensured based on antibiotic/antiseptic susceptibility test.Asian J. Med. Biol. Res. March 2018, 4(1): 105-116

scholarly journals Survival Comes at a Cost: A Coevolution of Phage and Its Host Leads to Phage Resistance and Antibiotic Sensitivity of Pseudomonas aeruginosa Multidrug Resistant Strains

2021 ◽  
Vol 12 ◽  
Author(s):  
Sarshad Koderi Valappil ◽  
Prateek Shetty ◽  
Zoltán Deim ◽  
Gabriella Terhes ◽  
Edit Urbán ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Sensitivity ◽  
Multidrug Resistant ◽  
Protein Characterization ◽  
Phage Resistance ◽  
Tail Fiber ◽  
Genomic Deletion ◽  
Clinical Strains

The increasing ineffectiveness of traditional antibiotics and the rise of multidrug resistant (MDR) bacteria have necessitated the revival of bacteriophage (phage) therapy. However, bacteria might also evolve resistance against phages. Phages and their bacterial hosts coexist in nature, resulting in a continuous coevolutionary competition for survival. We have isolated several clinical strains of Pseudomonas aeruginosa and phages that infect them. Among these, the PIAS (Phage Induced Antibiotic Sensitivity) phage belonging to the Myoviridae family can induce multistep genomic deletion in drug-resistant clinical strains of P. aeruginosa, producing a compromised drug efflux system in the bacterial host. We identified two types of mutant lines in the process: green mutants with SNPs (single nucleotide polymorphisms) and smaller deletions and brown mutants with large (∼250 kbp) genomic deletion. We demonstrated that PIAS used the MexXY-OprM system to initiate the infection. P. aeruginosa clogged PIAS phage infection by either modifying or deleting these receptors. The green mutant gaining phage resistance by SNPs could be overcome by evolved PIASs (E-PIASs) with a mutation in its tail-fiber protein. Characterization of the mutant phages will provide a deeper understanding of phage-host interaction. The coevolutionary process continued with large deletions in the same regions of the bacterial genomes to block the (E-)PIAS infection. These mutants gained phage resistance via either complete loss or substantial modifications of the phage receptor, MexXY-OprM, negating its essential role in antibiotic resistance. In vitro and in vivo studies indicated that combined use of PIAS and antibiotics could effectively inhibit P. aeruginosa growth. The phage can either eradicate bacteria or induce antibiotic sensitivity in MDR-resistant clinical strains. We have explored the potential use of combination therapy as an alternative approach against MDR P. aeruginosa infection.

In Vitro Synergistic Activity of Colistin and Ceftazidime or Ciprofloxacin Against Multidrug-Resistant Clinical Strains of Pseudomonas aeruginosa

2014 ◽  
Vol 20 (6) ◽  
pp. 550-554 ◽  
Author(s):  
Beena Benita D'Souza ◽  
Sunil Rao Padmaraj ◽  
Panchapaddy Devasya Rekha ◽  
Rouchelle Charmaine Tellis ◽  
Sudharshan Prabhu ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Synergistic Activity ◽  
Clinical Strains

scholarly journals Synergistic Antimicrobial Activity of Supplemented Medical-Grade Honey against Pseudomonas aeruginosa Biofilm Formation and Eradication

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 866
Author(s):  
Carlos C. F. Pleeging ◽  
Tom Coenye ◽  
Dimitris Mossialos ◽  
Hilde de Rooster ◽  
Daniela Chrysostomou ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Wound Healing ◽  
Broad Spectrum ◽  
Biofilm Formation ◽  
Wound Care ◽  
Multidrug Resistant ◽  
Synergistic Activity ◽  
Medical Grade

Biofilms hinder wound healing. Medical-grade honey (MGH) is a promising therapy because of its broad-spectrum antimicrobial activity and the lack of risk for resistance. This study investigated the inhibitory and eradicative activity against multidrug-resistant Pseudomonas aeruginosa biofilms by different established MGH-based wound care formulations. Six different natural wound care products (Medihoney, Revamil, Mebo, Melladerm, L-Mesitran Ointment, and L-Mesitran Soft) were tested in vitro. Most of them contain MGH only, whereas some were supplemented. L-Mesitran Soft demonstrated the most potent antimicrobial activity (6.08-log inhibition and 3.18-log eradication). Other formulations ranged between 0.89-log and 4.80-log inhibition and 0.65-log and 1.66-log eradication. Therefore, the contribution of different ingredients of L-Mesitran Soft was investigated in more detail. The activity of the same batch of raw MGH (1.38-log inhibition and 2.35-log eradication), vitamins C and E (0.95-log inhibition and 0.94-log eradication), and all ingredients except MGH (1.69-log inhibition and 0.75-log eradication) clearly support a synergistic activity of components within the L-Mesitran Soft formulation. Several presented clinical cases illustrate its clinical antimicrobial efficacy against Pseudomonas aeruginosa biofilms. In conclusion, MGH is a potent treatment for Pseudomonas biofilms. L-Mesitran Soft has the strongest antimicrobial activity, which is likely due to the synergistic activity mediated by its supplements.

scholarly journals Combined With Mefloquine, Resurrect Colistin Active in Colistin-Resistant Pseudomonas aeruginosa in vitro and in vivo

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaodong Zhang ◽  
Yining Zhao ◽  
Luozhu Feng ◽  
Mengxin Xu ◽  
Yiru Ge ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Synergistic Effect ◽  
Biofilm Formation ◽  
Galleria Mellonella ◽  
Synergistic Effects ◽  
Alternative Therapy ◽  
Multidrug Resistant ◽  
Infection Model

Colistin is a polymyxin antibiotic that is widely used for the treatment of multidrug resistant (MDR) Pseudomonas aeruginosa infections, as the last resort. Over the past few years, unreasonable use of antibiotics has resulted in an increase in MDR strains, including colistin-resistant P. aeruginosa. The present study aimed to explore the synergistic effects of mefloquine in combination with colistin for the treatment of colistin-resistant P. aeruginosa in vivo and in vitro. The synergistic effect of the combination of mefloquine and colistin was investigated in vitro using checkerboard method, time-killing assay, biofilm formation inhibition test, and biofilm eradication test. The study also explored the synergistic effects of this combination of drugs in vivo, using a Galleria mellonella infection model. The results for checkerboard method and time killing curve indicated that mefloquine in combination with colistin showed a good antibacterial activity. Furthermore, the combination of these two drugs inhibited biofilm formation and eradicated pre-formed mature biofilms. This synergistic effect was visualized using scanning electron microscopy (SEM), wherein the results showed that the combination of mefloquine and colistin reduced biofilm formation significantly. Further, the application of this combination of drugs to in vivo infection model significantly increased the survival rate of G. mellonella larvae. Altogether, the combination of mefloquine and colistin showed a good synergistic effect in vitro and in vivo, and highlighted its potential to be used as an alternative therapy for the treatment of colistin-resistant P. aeruginosa infection.

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