Effect of silver nanoparticles conjugated to thiosemicarbazide on biofilm formation and expression of intercellular adhesion molecule genes, icaAD, in Staphylococcus aureus

Montazeri, Ahmad; Salehzadeh, Ali; Zamani, Hojjatolah

doi:10.1007/s12223-019-00715-1

Cited by 24 publications

(17 citation statements)

References 29 publications

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“…In other words, the NPs inhibit cytoplasmic proteins via direct attachment which describe the reduced expression of biofilm-associated genes. Montazeri et al reported that at sub-inhibitory concentration of Ag-NPs conjugated to thiosemicarbazide reduced expression of ica A and ica D genes the biofilm formation related between methicillin resistance S. aureus, the results from this study support the finding [20]. In another study, Gheidar et al, showed that exposure to Ag-NPs reduced the expression of fnbA and fnbB genes [38].…”

Section: Discussionsupporting

confidence: 83%

“…Ag-NPs antibacterial mechanism works by inhibiting O 2 metabolism, which finally kills the microbes in a very short time [27]. Moreover, it has been reported that Ag-NPs could efficiently reduction bacterial biofilm biomass [20]. These findings indicate that the antibiofilm activity of 512 μg/ml of Ag-NPs and 256 μg/ml GSH-Ag-NPs could slightly degradation bacterial biofilm (Table 3).…”

Section: Discussionmentioning

confidence: 86%

“…Biofilm formation by bacteria causes higher resistance to antimicrobials due to the decrease of antimicrobial penetration and easier exchange of resistance genes between bacteria. Therefore, biofilm formation is regarded as an essential pathogenicity determinant and the resulting infections are challenging to treat [20]. The world spread of antibiotic resistance has increased the need to develop new antimicrobial agents.…”

Section: Discussionmentioning

confidence: 99%

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Effect of glutathione-stabilized silver nanoparticles on expression of las I and las R of the genes in Pseudomonas aeruginosa strains

Mahnaie

Mahmoudi

2020

Eur J Med Res

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Background: Biofilm formation is regarded as a significant factor in the establishment of infections caused by Pseudomonas aeruginosa. P. aeruginosa is one of the most important causes of nosocomial infections. Today silver nanoparticles (Ag-NPs) are used as antimicrobials due to their well-known, chemical, biological, and physical properties. Exposure to nanoparticles could inhibit colonization of new bacteria onto the biofilm. Methods: In the present work, the green synthesis of Ag-NPs was performed using the alcoholic extract of Eucalyptus camaldulensis. Ag-NPs and glutathione-stabilized silver nanoparticles (GSH-Ag-NPs) were characterized using X-ray diffraction (XRD), dynamic light scattering (DLS), scanning electron microscope (SEM), and carbon, nitrogen, and hydrogen (CNH) and Fourier transform infrared spectroscopy (FTIR) techniques were applied to investigate the structure of the modified nanoparticles. Then, the antimicrobial and antibiofilm potential of the prepared Ag-NPs and GSH-Ag-NPs against P. aeruginosa strains was evaluated using microbroth dilution method and their effects on the expression of las I and las R genes. Results: In this study, a total of 50 P. aeruginosa isolates were recovered from clinical samples. According to the results, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) value of Ag-NPs against P. aeruginosa was determined to be 512-256 μg/ml, respectively, while the MIC and MBC value of GS-Ag-NPs against P. aeruginosa clinical strains was determined in a range of 128-256 μg/ml and 256-512 μg/ml, respectively. The mean expression level in las R, las I genes in P. aeruginosa strains treated with ½ MIC of Ag-NPs was decreased by −5.7 and −8fold, respectively. The mean expression levels of las R, las I genes in P. aeruginosa strains treated with ½ MIC of GS-Ag-NPs were decreased by −8.7 and −10fold, respectively (P < 0.05). Conclusions: The results of our study showed that Ag-NPs and GS-Ag-NPs are highly effective against P. aeruginosa strains. Moreover, this study also proves the promising potential of using nanoparticles as anti-biofilm formation and antibacterial agents.

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Section: Discussionsupporting

confidence: 83%

Section: Discussionmentioning

confidence: 86%

Section: Discussionmentioning

confidence: 99%

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Effect of glutathione-stabilized silver nanoparticles on expression of las I and las R of the genes in Pseudomonas aeruginosa strains

Mahnaie

Mahmoudi

2020

Eur J Med Res

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“…However, the mechanism that allows the inhibition of bio lm formation is not clear. Many studies have shown that polysaccharide intercellular adhesin (PIA) is the primary determinant of the accumulation phase of staphylococcal bio lm formation [21][22][23] . Although bacteria with PIA de ciency have been able to adhere to the surface of medical implants at the initial stage of bio lm formation, the ability of a large number of colonies to gather and form bio lm at the later stage were greatly reduced, and even bacterial bio lms could not be formed 3,6,23 .…”

Section: Discussionmentioning

confidence: 99%

“…It can be seen that the co-expression of the functional ica A and ica D gene can catalyze the synthesis of PIA, and the down-regulation of ica AD expression leads to the reduced activity of N-acetylglucosaminyl transferase, which also leads to reduced amount of PIA [24][25][26] . In addition, studies have shown that the complex gene regulation system of staphylococcus may ultimately in uence the bio lm formation by regulating the expression of ica operon 23,26 . Therefore, in order to verify the role of ica operon in the inhibition of bacterial bio lm formation on the titanium surface by SH decoction, ATCC 35984 with property of positive bio lm formation and ica AD gene expression was selected in this study 11 .…”

Section: Discussionmentioning

confidence: 99%

Adhesion and biofilm inhibiting properties of Chinese Herbal Formula SanHuang decoction against antibiotic resistant staphylococcal strains

Zhang

Wang

Shi

et al. 2020

Preprint

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Clinical study has shown that external socking and washing with the Chinese herbal SanHuang decoction (SH) can control the orthopedic-biofilm related infections. However, the antibiofilm activities of SH in vitro have not been investigated. The aim of the current study was to explore the effect of SH on adhesion and biofilm formation of antibiotic-resistant staphylococci on titanium surface, and to explore its probable mechanistic effects on staphylococcal strains. Biofilm-forming ATCC 35984 (methicillin-resistant Staphylococcus epidermidis, MRSE) and ATCC 43300 (methicillin-resistant Staphylococcus aureus, MRSA) strains were used in this study. The minimum inhibitory concentrations (MICs) of SH and vancomycin against planktonic bacterial strains were determined by the broth microdilution method. Different sub-MIC of SH with TSB (Tryptic soy broth) were used as the basis for experimental grouping (SH group). TSB culture medium alone (TSB group) or TSB containing vancomycin (vancomycin group) incubated with bacteria were considered as the negative or positive control group, respectively. The inhibitory effect of different treatment on bacterial adhesion and biofilm formation were observed by the spread plate method, CV (crystal violet) staining, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM). Real time PCR analysis was performed to determine the effect of SH on the expression levels of ica AD and ica R gene in ATCC 35984 during the biofilm formation. The strains were found to be susceptible to SH decoction with MIC and MBC values of 38.75 mg/ml and 77.5 mg/ml, respectively. The MIC values for vancomycin was 2.5 μg/ml. SH treatment with 1 MIC and 1/2 MIC could inhibit the bacteria adhesion on the titanium surface, showing only scattered bacterial adhesion from SEM. CLSM showed that SH with 1 MIC and 1/2 MIC could also inhibit the bacterial biofilm formation. The quantitative results of the spread plate method and CV staining showed that there was significant differences between the SH groups (P < 0.05). Further, with an increase in SH concentration, the inhibitory effect became more obvious at different culture time points, when compared with TSB control group (P < 0.05). Among the groups, vancomycin had the strongest inhibitory effect on bacterial adhesion and biofilm formation (P < 0.01). Meanwhile, with an increase in SH concentration, the expression levels of ica A and ica D decreased, and the expression of ica R increased correspondingly (P < 0.05). In conclusions, a certain concentration of SH can inhibit the adhesion and biofilm formation of antibiotic-resistant Staphylococcal strains on the titanium surface, but the effect was not as good as vancomycin. Its probable mechanistic activity may be through the inhibition of polysaccharide intercellular adhesin synthesis by down-regulating the expression of ica AD gene, thus inhibiting bacterial biofilm formation.

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Fabrication and Characterization of Thymol‐Loaded Chitosan Nanogels: Improved Antibacterial and Anti‐Biofilm Activities with Negligible Cytotoxicity

Gharaghie

Beiranvand

Riahi

et al. 2022

Chemistry & Biodiversity

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Thymol is a monoterpene phenolic derivative extracted from the Thymus vulgaris which has antimicrobial effects. In the present study, thymol-loaded chitosan nanogels were prepared and their physicochemical properties were characterized. The encapsulation efficiency of thymol into chitosan and its stability were determined. The in vitro antimicrobial and anti-biofilm activities of thymol-loaded chitosan nanogel (Ty-CsNG), free thymol (Ty), and free chitosan nanogel (CsNG) were evaluated against both Gram-negative and Grampositive multidrug-resistant (MDR) bacteria including Staphylococcus aureus, Acinetobacter baumanii, and Pseudomonas aeruginosa strains using the broth microdilution and crystal violet assay, respectively. After treatment of MDR strains with sub-minimum inhibitory concentration (Sub-MIC) of Ty-CsNG, free Ty and CsNG, biofilm gene expression analysis was studied. Moreover, cytotoxicity of Ty-CsNG, free Ty, and CsNG against HEK-293 normal cell line was determined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method. The average size of Ty-CsNG was 82.71 � 9.6 nm, encapsulation efficiency was 76.54 � 0.62 % with stability up to 60 days at 4 °C. Antibacterial activity test revealed that Ty-CsNG reduced the MIC by 4 -6 times in comparison to free thymol. In addition, the expression of biofilm-related genes including ompA, and pgaB were significantly down-regulated after treatment of strains with Ty-CsNG (P < 0.05). In addition, free CsNG displayed negligible cytotoxicity against HEK-293 normal cell lines and presented a biocompatible nanoscale delivery system. Based on the results, it can be concluded that Ty-CsNG can be considered a promising candidate for enhancing antimicrobial and anti-biofilm activities.

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Effect of silver nanoparticles conjugated to thiosemicarbazide on biofilm formation and expression of intercellular adhesion molecule genes, icaAD, in Staphylococcus aureus

Cited by 24 publications

References 29 publications

Effect of glutathione-stabilized silver nanoparticles on expression of las I and las R of the genes in Pseudomonas aeruginosa strains

Effect of glutathione-stabilized silver nanoparticles on expression of las I and las R of the genes in Pseudomonas aeruginosa strains

Adhesion and biofilm inhibiting properties of Chinese Herbal Formula SanHuang decoction against antibiotic resistant staphylococcal strains

Fabrication and Characterization of Thymol‐Loaded Chitosan Nanogels: Improved Antibacterial and Anti‐Biofilm Activities with Negligible Cytotoxicity

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