scholarly journals Benefits of Usage of Immobilized Silver Nanoparticles as Pseudomonas aeruginosa Antibiofilm Factors

2021 ◽  
Vol 23 (1) ◽  
pp. 284
Author(s):  
Kamila Korzekwa ◽  
Anna Kędziora ◽  
Bartłomiej Stańczykiewicz ◽  
Gabriela Bugla-Płoskońska ◽  
Dorota Wojnicz

The aim of this study was to assess the beneficial inhibitory effect of silver nanoparticles immobilized on SiO2 or TiO2 on biofilm formation by Pseudomonas aeruginosa—one of the most dangerous pathogens isolated from urine and bronchoalveolar lavage fluid of patients hospitalized in intensive care units. Pure and silver doped nanoparticles of SiO2 and TiO2 were prepared using a novel modified sol-gel method. Ten clinical strains of P. aeruginosa and the reference PAO1 strain were used. The minimal inhibitory concentration (MIC) was determined by the broth microdilution method. The minimal biofilm inhibitory concentration (MBIC) and biofilm formation were assessed by colorimetric assay. Bacterial enumeration was used to assess the viability of bacteria in the biofilm. Silver nanoparticles immobilized on the SiO2 and TiO2 indicated high antibacterial efficacy against P. aeruginosa planktonic and biofilm cultures. TiO2/Ag0 showed a better bactericidal effect than SiO2/Ag0. Our results indicate that the inorganic compounds (SiO2, TiO2) after nanotechnological modification may be successfully used as antibacterial agents against multidrug-resistant P. aeruginosa strains.

Author(s):  
Fateme Davarzani ◽  
Zahra Yousefpour ◽  
Navid Saidi ◽  
Parviz Owlia

Background and Objectives: Antibiotics at sub-minimum inhibitory concentrations (sub-MIC) may alter bacterial viru- lence factors. The objective of this study was to investigate the effect of gentamicin at sub-MIC concentrations on the expres- sion of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa. Materials and Methods: The broth microdilution method was used to determine the MIC of gentamicin for three P. aeru- ginosa clinical isolates (P1-P3) and standard strains (PAO1 and 8821M). Alginate production and biofilm formation of the bacteria in the presence and absence of sub-MIC concentrations of gentamicin were measured using microtiter plate and carbazole assay, respectively. The real-time PCR method was used to determine the effect of gentamicin at sub-MIC con- centrations on the expression level of genes involved in biofilm formation (pelA and pslA) and alginate production (algD and algU). Results: Gentamicin at sub-MIC concentrations significantly reduced alginate production, biofilm formation, and the expres- sion of alginate and biofilm-encoding genes in clinical isolate P1. This inhibitory effect was also observed on the alginate production of 8821M strain and biofilm formation of PAO1strain. In clinical isolates, P2 and P3, alginate production, biofilm formation, and the expression of alginate and biofilm-encoding genes were significantly increased in exposure to sub-MIC concentrations of gentamicin. Conclusion: This study showed that different phenotypic changes in clinical isolates and standard strains of P. aeruginosa in exposure to sub-MIC concentrations of gentamicin are associated with changes in the expression of virulence genes. Further researches are required to understand the mechanisms involved in regulating the expression of virulence genes after exposure to sub-MIC concentrations of antibiotics.


2020 ◽  
Vol 148 (3-4) ◽  
pp. 196-202
Author(s):  
Snjezana Petrovic ◽  
Jasmina Basic ◽  
Zoran Mandinic ◽  
Dragana Bozic ◽  
Marina Milenkovic ◽  
...  

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.


2010 ◽  
Vol 79 (2) ◽  
pp. 340-344 ◽  
Author(s):  
Kalimuthu Kalishwaralal ◽  
Selvaraj BarathManiKanth ◽  
Sureshbabu Ram Kumar Pandian ◽  
Venkataraman Deepak ◽  
Sangiliyandi Gurunathan

2021 ◽  
Vol 151 ◽  
pp. 106058
Author(s):  
Felix LewisOscar ◽  
Chari Nithya ◽  
Sasikumar Vismaya ◽  
Manivel Arunkumar ◽  
Arivalagan Pugazhendhi ◽  
...  

2020 ◽  
Vol 4 ◽  
Author(s):  
Fatima Reyes-Jurado ◽  
Ricardo Munguía-Pérez ◽  
Teresa Soledad Cid-Pérez ◽  
Paola Hernández-Carranza ◽  
Carlos Enrique Ochoa-Velasco ◽  
...  

2013 ◽  
Vol 57 (4) ◽  
pp. 1921-1925 ◽  
Author(s):  
Kenneth S. Brandenburg ◽  
Karien J. Rodriguez ◽  
Jonathan F. McAnulty ◽  
Christopher J. Murphy ◽  
Nicholas L. Abbott ◽  
...  

ABSTRACTBiofilm formation byPseudomonas aeruginosahas been implicated in the pathology of chronic wounds. Both thedandlisoforms of tryptophan inhibitedP. aeruginosabiofilm formation on tissue culture plates, with an equimolar ratio ofdandlisoforms producing the greatest inhibitory effect. Addition ofd-/l-tryptophan to existing biofilms inhibited further biofilm growth and caused partial biofilm disassembly. Tryptophan significantly increased swimming motility, which may be responsible in part for diminished biofilm formation byP. aeruginosa.


2018 ◽  
Vol 4 (1) ◽  
pp. 95-107
Author(s):  
Nasrin Esfahanizadeh ◽  
Mohammad Reza Nourani ◽  
Abbas Bahador ◽  
Nasrin Akhondi ◽  
Mostafa Montazeri

Abstract Colonization of periodontal pathogens on the surgical sites is one of the primary reasons for the failure of regenerative periodontal therapies. Bioactive glasses (BGs) owing to their favorable structural and antimicrobial properties have been proposed as promising materials for the reconstruction of periodontal and peri-implant bone defects. This study aimed to investigate the antibiofilm activity of zinc-doped BG (Zn/BG) compared with 45S5 Bioglass® (BG®) on putative periodontal pathogens. In this in vitro experimental study, the nano BG doped with 5-mol% zinc and BG® were synthesized by sol-gel method. Mono-species biofilms of Aggregatibacter actinomycetemcomitans (A. a), Porphyromonas gingivalis (P. g), and Prevotella intermedia (P. i)were prepared separately in a well-containing microplate. After 48 hours of exposure to generated materials at 37°C, the anti-biofilm potential of the samples was studied by measuring the optical density (OD) at 570nm wavelengths with a microplate reader. Two-way ANOVA then analyzed the results. Both Zn/BG and BG® significantly reduced the biofilm formation ability of all examined strains after 48 hours of incubation (P=0.0001). Moreover, the anti-biofilm activity of Zn/BG was significantly stronger than BG® (P=0.0001), which resulted in the formation of a weak biofilm (OD<1) compared with a moderately adhered biofilm observed with BG® (1<OD<2). Zn/BG showed a significant inhibitory effect on the biofilm formation of all examined periodontal pathogens. Given the enhanced regenerative and anti-biofilm properties of this novel biomaterial, further investigations are required for its implementation in clinical situations.


Author(s):  
Borel Bisso Ndezo ◽  
Christian Ramsès Tokam Kuaté ◽  
Jean Paul Dzoyem

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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