scholarly journals The combination of silver-containing hydroxyapatite coating and vancomycin has a synergistic antibacterial effect on methicillin-resistant Staphylococcus aureus biofilm formation

2020 ◽  
Vol 9 (5) ◽  
pp. 211-218
Author(s):  
Akira Hashimoto ◽  
Hiroshi Miyamoto ◽  
Tomoki Kobatake ◽  
Takema Nakashima ◽  
Takeo Shobuike ◽  
...  

Aims Biofilm formation is intrinsic to prosthetic joint infection (PJI). In the current study, we evaluated the effects of silver-containing hydroxyapatite (Ag-HA) coating and vancomycin (VCM) on methicillin-resistant Staphylococcus aureus (MRSA) biofilm formation. Methods Pure titanium discs (Ti discs), Ti discs coated with HA (HA discs), and 3% Ag-HA discs developed using a thermal spraying were inoculated with MRSA suspensions containing a mean in vitro 4.3 (SD 0.8) x 106 or 43.0 (SD 8.4) x 105 colony-forming units (CFUs). Immediately after MRSA inoculation, sterile phosphate-buffered saline or VCM (20 µg/ml) was added, and the discs were incubated for 24 hours at 37°C. Viable cell counting, 3D confocal laser scanning microscopy with Airyscan, and scanning electron microscopy were then performed. HA discs and Ag HA discs were implanted subcutaneously in vivo in the dorsum of rats, and MRSA suspensions containing a mean in vivo 7.2 (SD 0.4) x 106  or 72.0 (SD 4.2) x 105  CFUs were inoculated on the discs. VCM was injected subcutaneously daily every 12 hours followed by viable cell counting. Results Biofilms that formed on HA discs were thicker and larger than those on Ti discs, whereas those on Ag-HA discs were thinner and smaller than those on Ti discs. Viable bacterial counts in vivo revealed that Ag-HA combined with VCM was the most effective treatment. Conclusion Ag-HA with VCM has a potential synergistic effect in reducing MRSA biofilm formation and can thus be useful for preventing and treating PJI. Cite this article: Bone Joint Res. 2020;9(5):211–218.

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Shizhou Wu ◽  
Yunjie Liu ◽  
Hui Zhang ◽  
Lei Lei

Aim. Antibiotic abuse contributes to the emergence of methicillin-resistant Staphylococcus aureus (MRSA). It is increasingly important to screen new antimicrobial agents for the management of MRSA infections. G. chinensis, a nontoxic Chinese herbal medicine, is considered a potential antibacterial agent. The aim of this study was to investigate the bactericidal effects of the aqueous extracts of G. chinensis on MRSA. The potential mechanisms of G. chinensis aqueous extract inhibition of the pathogenicity of MRSA in vivo are also discussed. Methods. G. chinensis aqueous extract was prepared and its antimicrobial activities were examined by determining its minimum inhibitory concentration (MIC). Biofilm biomass was determined by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). RNA sequencing (RNA-seq) was used to evaluate differentially expressed functional pathways in MRSA treated with G. chinensis aqueous extract. We validated the role of G. chinensis aqueous extract in the invasive ability and pathogenicity of MRSA in vivo using a rat infectious model. Results. The results indicated that MRSA was sensitive to the G. chinensis aqueous extracts at concentration of 31.25μg/mL. G. chinensis extract led to a reduction in dextran-dependent aggregation and biofilm formation in MRSA. Based on the transcriptome analysis, G. chinensis aqueous extracts significantly downregulated the gene expression related to biofilm formation and carbohydrate metabolism. G. chinensis aqueous extract inhibited the invasive ability and the pathogenicity of MRSA in vivo. Conclusion. The antimicrobial properties of G. chinensis aqueous extract are likely related to its modulation of MRSA biofilm formation and carbohydrate metabolism. G. chinensis aqueous extract is a promising supplementary therapy to lessen or eliminate the use of antibiotics and is a potential tool for the management of MRSA infections.


ACS Omega ◽  
2020 ◽  
Vol 5 (48) ◽  
pp. 31100-31114
Author(s):  
Anthonymuthu Selvaraj ◽  
Alaguvel Valliammai ◽  
Pandiyan Muthuramalingam ◽  
Arumugam Priya ◽  
Manokaran Suba ◽  
...  

2022 ◽  
Vol 12 ◽  
Author(s):  
Lulin Rao ◽  
Yaoguang Sheng ◽  
Jiao Zhang ◽  
Yanlei Xu ◽  
Jingyi Yu ◽  
...  

The resistance of methicillin-resistant Staphylococcus aureus (MRSA) has augmented due to the abuse of antibiotics, bringing about difficulties in the treatment of infection especially with the formation of biofilm. Thus, it is essential to develop antimicrobials. Here we synthesized a novel small-molecule compound, which we termed SYG-180-2-2 (C21H16N2OSe), that had antibiofilm activity. The aim of this study was to demonstrate the antibiofilm effect of SYG-180-2-2 against clinical MRSA isolates at a subinhibitory concentration (4 μg/ml). In this study, it was showed that significant suppression in biofilm formation occurred with SYG-180-2-2 treatment, the inhibition ranged between 65.0 and 85.2%. Subsequently, confocal laser scanning microscopy and a bacterial biofilm metabolism activity assay further demonstrated that SYG-180-2-2 could suppress biofilm. Additionally, SYG-180-2-2 reduced bacterial adhesion and polysaccharide intercellular adhesin (PIA) production. It was found that the expression of icaA and other biofilm-related genes were downregulated as evaluated by RT-qPCR. At the same time, icaR and codY were upregulated when biofilms were treated with SYG-180-2-2. Based on the above results, we speculate that SYG-180-2-2 inhibits the formation of biofilm by affecting cell adhesion and the expression of genes related to PIA production. Above all, SYG-180-2-2 had no toxic effects on human normal alveolar epithelial cells BEAS-2B. Collectively, the small-molecule compound SYG-180-2-2 is a safe and effective antibacterial agent for inhibiting MRSA biofilm.


2013 ◽  
Vol 57 (10) ◽  
pp. 5045-5052 ◽  
Author(s):  
Zheng Hou ◽  
Fei Da ◽  
Baohui Liu ◽  
Xiaoyan Xue ◽  
Xiuli Xu ◽  
...  

ABSTRACTStaphylococcus epidermidisis one of the most frequent causes of device-associated infections, because it is known to cause biofilms that grow on catheters or other surgical implants. The persistent increasing resistance ofS. epidermidisand other coagulase-negative staphylococci (CoNS) has driven the need for newer antibacterial agents with innovative therapeutic strategies. Thanatin is reported to display potent antibiotic activities, especially against extended-spectrum-beta-lactamase-producingEscherichia coli. The present study aimed to investigate whether a shorter derivative peptide (R-thanatin) could be used as a novel antibacterial agent. We found that R-thanatin was highly potentin vitroagainst coagulase-negative staphylococci, such asS. epidermidis,S. haemolyticus, andS. hominis, and inhibited biofilm formation at subinhibitory concentrations. Properties of little toxicity to human red blood cells (hRBCs) and human umbilical vein endothelial cells, a low incidence of resistance, and relatively high stability in plasma were confirmed. Excellentin vivoprotective effects were also observed using a methicillin-resistantS. epidermidis(MRSE)-induced urinary tract infection rat model. Electron microscopy and confocal laser-scanning microscopy analyses suggested that R-thanatin disturbed cell division of MRSE severely, which might be the reason for inhibition of MRSE growth. These findings indicate that R-thanatin is active against the growth and biofilm formation of MRSEin vitroandin vivo. R-thanatin might be considered as a specific drug candidate for treating CoNS infections.


Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1731
Author(s):  
Yu Maw Htwe ◽  
Huashan Wang ◽  
Patrick Belvitch ◽  
Lucille Meliton ◽  
Mounica Bandela ◽  
...  

Lung endothelial dysfunction is a key feature of acute lung injury (ALI) and clinical acute respiratory distress syndrome (ARDS). Previous studies have identified the lipid-generating enzyme, group V phospholipase A2 (gVPLA2), as a mediator of lung endothelial barrier disruption and inflammation. The current study aimed to determine the role of gVPLA2 in mediating lung endothelial responses to methicillin-resistant Staphylococcus aureus (MRSA, USA300 strain), a major cause of ALI/ARDS. In vitro studies assessed the effects of gVPLA2 inhibition on lung endothelial cell (EC) permeability after exposure to heat-killed (HK) MRSA. In vivo studies assessed the effects of intratracheal live or HK-MRSA on multiple indices of ALI in wild-type (WT) and gVPLA2-deficient (KO) mice. In vitro, HK-MRSA increased gVPLA2 expression and permeability in human lung EC. Inhibition of gVPLA2 with either the PLA2 inhibitor, LY311727, or with a specific monoclonal antibody, attenuated the barrier disruption caused by HK-MRSA. LY311727 also reduced HK-MRSA-induced permeability in mouse lung EC isolated from WT but not gVPLA2-KO mice. In vivo, live MRSA caused significantly less ALI in gVPLA2 KO mice compared to WT, findings confirmed by intravital microscopy assessment in HK-MRSA-treated mice. After targeted delivery of gVPLA2 plasmid to lung endothelium using ACE antibody-conjugated liposomes, MRSA-induced ALI was significantly increased in gVPLA2-KO mice, indicating that lung endothelial expression of gVPLA2 is critical in vivo. In summary, these results demonstrate an important role for gVPLA2 in mediating MRSA-induced lung EC permeability and ALI. Thus, gVPLA2 may represent a novel therapeutic target in ALI/ARDS caused by bacterial infection.


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