Control of Foodborne Staphylococcus aureus by Shikonin, a Natural Extract

Foodborne Staphylococcus aureus (S. aureus) has attracted widespread attention due to its foodborne infection and food poisoning in human. Shikonin exhibits antibacterial activity against a variety of microorganisms, but there are few studies on its antibacterial activity against S. aureus. This study aims to explore the antibacterial activity and mechanism of shikonin against foodborne S. aureus. The results show that the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of shikonin were equal for all tested strains ranging from 35 μg/mL to 70 μg/mL. Shikonin inhibited the growth of S. aureus by reducing intracellular ATP concentrations, hyperpolarizing cell membrane, destroying the integrity of cell membrane, and changing cell morphology. At the non-inhibitory concentrations (NICs), shikonin significantly inhibited biofilm formation of S. aureus, which was attributed to inhibiting the expression of cidA and sarA genes. Moreover, shikonin also markedly inhibited the transcription and expression of virulence genes (sea and hla) in S. aureus. In addition, shikonin has exhibited antibacterial ability against both planktonic and biofilm forms of S. aureus. Importantly, in vivo results show that shikonin has excellent biocompatibility. Moreover, both the heat stability of shikonin and the antimicrobial activity of shikonin against S. aureus were excellent in food. Our findings suggest that shikonin are promising for use as a natural food additive, and it also has great potential in effectively controlling the contamination of S. aureus in food and reducing the number of illnesses associated with S. aureus.

Download Full-text

Silver-Containing Hydroxyapatite Coating Reduces Biofilm Formation by Methicillin-ResistantStaphylococcus aureusIn Vitro and In Vivo

BioMed Research International ◽

10.1155/2016/8070597 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 11

Author(s):

Masaya Ueno ◽

Hiroshi Miyamoto ◽

Masatsugu Tsukamoto ◽

Shuichi Eto ◽

Iwao Noda ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Biofilm Formation ◽

Thermal Spraying ◽

Time Points ◽

High Antibacterial Activity ◽

Ha Coating ◽

Coverage Rates

Biofilm-producing bacteria are the principal causes of infections associated with orthopaedic implants. We previously reported that silver-containing hydroxyapatite (Ag-HA) coatings exhibit high antibacterial activity against methicillin-resistantStaphylococcus aureus(MRSA). In the present study, we evaluated the effects of Ag-HA coating of implant surfaces on biofilm formation. Titanium disks (14-mm diameter, 1-mm thickness), one surface of which was coated with HA or 0.5%–3.0% Ag-HA with a thermal spraying technique, were used. In vitro, the disks were inoculated with an MRSA suspension containing4×105 CFU and incubated for 1-2 weeks. In vivo, MRSA-inoculated HA and 3% Ag-HA disks (8.8–10.0 × 108 CFU) were implanted subcutaneously on the back of rats for 1–7 days. All disks were subsequently stained with a biofilm dye and observed under a fluorescence microscope, and biofilm coverage rates (BCRs) were calculated. The BCRs on the Ag-HA coating were significantly lower than those on the HA coating at all time points in vitro (p<0.05). Similar results were observed in vivo (p<0.001) without argyria. Ag-HA coating reduced biofilm formation by MRSA in vitro and in vivo; therefore, Ag-HA coating might be effective for reducing implant-associated infections.

Download Full-text

Antibacterial activity of xanthan-oligosaccharide against Staphylococcus aureus via targeting biofilm and cell membrane

International Journal of Biological Macromolecules ◽

10.1016/j.ijbiomac.2020.03.044 ◽

2020 ◽

Vol 153 ◽

pp. 539-544 ◽

Cited By ~ 1

Author(s):

Zichao Wang ◽

Qingqing Yang ◽

Xueqin Wang ◽

Ruifang Li ◽

Hanzhen Qiao ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Cell Membrane

Download Full-text

Assessment of in vivo versus in vitro biofilm formation of clinical methicillin-resistant Staphylococcus aureus isolates from endotracheal tubes

Scientific Reports ◽

10.1038/s41598-018-30494-7 ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 8

Author(s):

Laia Fernández-Barat ◽

Soumaya Ben-Aicha ◽

Anna Motos ◽

Jordi Vila ◽

Francesc Marco ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Biofilm Formation ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistant ◽

Endotracheal Tubes

Download Full-text

Anaerobic Conditions Induce Expression of Polysaccharide Intercellular Adhesin in Staphylococcus aureus and Staphylococcus epidermidis

Infection and Immunity ◽

10.1128/iai.69.6.4079-4085.2001 ◽

2001 ◽

Vol 69 (6) ◽

pp. 4079-4085 ◽

Cited By ~ 222

Author(s):

Sarah E. Cramton ◽

Martina Ulrich ◽

Friedrich Götz ◽

Gerd Döring

Keyword(s):

Staphylococcus Aureus ◽

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Extracellular Polysaccharide ◽

Growth Conditions ◽

Anaerobic Conditions ◽

Anaerobic Environment ◽

Specific Mrna

ABSTRACT Products of the intercellular adhesion (ica) operon in Staphylococcus aureus and Staphylococcus epidermidis synthesize a linear β-1,6-linked glucosaminylglycan. This extracellular polysaccharide mediates bacterial cell-cell adhesion and is required for biofilm formation, which is thought to increase the virulence of both pathogens in association with prosthetic biomedical implants. The environmental signal(s) that triggers ica gene product and polysaccharide expression is unknown. Here we demonstrate that anaerobic in vitro growth conditions lead to increased polysaccharide expression in both S. aureus and S. epidermidis, although the regulation is less stringent inS. epidermidis. Anaerobiosis also dramatically stimulates ica-specific mRNA expression inica- and polysaccharide-positive strains of both S. aureus and S. epidermidis.These data suggest a mechanism whereby ica gene expression and polysaccharide production may act as a virulence factor in an anaerobic environment in vivo.

Download Full-text

Expression of icaA and icaD genes in biofilm formation in Staphylococcus aureus isolates from bovine subclinical mastitis

Pesquisa Veterinária Brasileira ◽

10.1590/1678-5150-pvb-6645 ◽

2021 ◽

Vol 41 ◽

Author(s):

Viviane F. Marques ◽

Huarrisson A. Santos ◽

Thomas H. Santos ◽

Dayanne A. Melo ◽

Shana M.O. Coelho ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Biofilm Formation ◽

Phenotypic Expression ◽

Bovine Mastitis ◽

Subclinical Mastitis ◽

Transcriptional Analysis ◽

Important Species ◽

High Prevalence ◽

Staphylococcus Spp

ABSTRACT: Staphylococcus spp. plays a significant role in the etiology of bovine mastitis. Staphylococcus aureus is considered the most important species due to the high prevalence and the difficulty of in vivo treatment that is related to the expression of virulence factors and biofilm formation. This study aimed to detect the phenotypic expression of the biofilm formation in 20 S. aureus isolated from bovine mastitis and to evaluate the expression and regulation of genes involved in its production. MALDI-TOF and phenogenotypic identification assays were performed to characterize the isolates. The phenotypic biofilm production and the presence of icaA and icaD and bap genes were evaluated. The Agr system was typified (agr I, agr II, agr III and agr IV) and its regulator (agr RNAIII) was detected. Furtherly, Real-time PCR (qPCR) was performed at chosen times to quantify the expression of icaA, icaD and hld genes in three selected isolates. All 20 strains were biofilm producers and most presented icaA and icaD genes. Only one isolate presented the bap gene. The agr gene type II showed a prevalence of 70%. Transcriptional analysis revealed increased expression of ica genes at eight hours of growth. These results confirm that polysaccharides production mediated by the icaADBC operon genes is an essential mechanism to the biofilm formation and contributes to the early stages of bacterial growth.

Download Full-text

In vitro and in vivo evaluation of antibacterial activity of Bridelia ferruginea extracts on some clinical isolates

The Journal of Phytopharmacology ◽

10.31254/phyto.2018.7407 ◽

2018 ◽

Vol 7 (4) ◽

pp. 392-398

Author(s):

B.T Yunana ◽

◽

B. B Bukar ◽

J. C Aguiyi ◽

◽

...

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Bark Extract ◽

Root Extract ◽

Root Bark ◽

Zone Of Inhibition ◽

Bridelia Ferruginea

The ethanol extracts of root, bark and leaf of Bridelia ferruginea was investigated for antibacterial activity against clinical isolate of Staphylococcus aureus and Escherichia coli. The extracts had significant antibacterial activity in vitro at concentration of 25 mg/ml, 50 mg/ml, 100 mg/ml and 200 mg/ml and in vivo at dose of 50 mg/kg and 100 mg/kg. The root extract in vitro had the highest zone of inhibition, followed by the bark extract for both Staphylococcus aureus and Escherichia coli. The concentration of 200 mg/ml had the highest zone of inhibition in vitro. The minimum inhibitory concentration (MIC) showed a decreasing inhibitory effect of the plant extracts for both Staphylococcus aureus and Escherichia coli as the concentration decreases with root having 3.125 mg/ml, bark having 6.25 mg/ml and leaf having 25 mg/ml for Staphylococcus aureus and Escherichia coli. Likewise, the minimum bactericidal concentration (MBC) showed decreasing bactericide effects with decrease concentration with root having 12.5 mg/ml, bark having 12.5 mg/ml and leaf having 25 mg/ml for Escherichia coli while root had 6.25mg/ml, bark had 12.5mg/ml and leaf had 25mg/ml for Staphylococcus aureus. The in vivo investigation showed that the root and bark extract exhibited antibacterial activity on both Staphylococcus aureus and Escherichia coli at doses of 100mg/kg and 50mg/kg; the root extract had higher activity than the bark and root/bark combined. The dose of 100 mg/kg had the highest colonies reduction for Staphylococcus aureus and Escherichia coli in vivo. Preliminary phytochemical screening of root, bark and leaves of Bridelia ferruginea revealed the presence of tannins, flavonoids, carbohydrates, cardiac glycoside (root, bark and leaves), saponins (root and bark). The presence of tannins, saponins, flavonoid, cardiac glycoside and carbohydrate in the bark and root extracts of the plant indicates that the bark and root extracts were pharmacological importance

Download Full-text

The Pathogenicity and Transcriptome Analysis of Methicillin-Resistant Staphylococcus aureus in Response to Water Extract of Galla chinensis

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2019/3276156 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

Shizhou Wu ◽

Yunjie Liu ◽

Hui Zhang ◽

Lei Lei

Keyword(s):

Staphylococcus Aureus ◽

Carbohydrate Metabolism ◽

Aqueous Extract ◽

Transcriptome Analysis ◽

Biofilm Formation ◽

Laser Scanning Microscopy ◽

Aqueous Extracts ◽

Invasive Ability ◽

Methicillin Resistant

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.

Download Full-text

Antibacterial Activity and Mechanism of Ginger Essential Oil against Escherichia coli and Staphylococcus aureus

Molecules ◽

10.3390/molecules25173955 ◽

2020 ◽

Vol 25 (17) ◽

pp. 3955 ◽

Cited By ~ 1

Author(s):

Xin Wang ◽

Yi Shen ◽

Kiran Thakur ◽

Jinzhi Han ◽

Jian-Guo Zhang ◽

...

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Essential Oil ◽

Cell Membrane ◽

Bacterial Cell ◽

Tricarboxylic Acid Cycle ◽

Inhibition Zone ◽

Underlying Mechanism ◽

Bacterial Suspension

Though essential oils exhibit antibacterial activity against food pathogens, their underlying mechanism is understudied. We extracted ginger essential oil (GEO) using supercritical CO2 and steam distillation. A chemical composition comparison by GC-MS showed that the main components of the extracted GEOs were zingiberene and α-curcumene. Their antibacterial activity and associated mechanism against Staphylococcus aureus and Escherichia coli were investigated. The diameter of inhibition zone (DIZ) of GEO against S. aureus was 17.1 mm, with a minimum inhibition concentration (MIC) of 1.0 mg/mL, and minimum bactericide concentration (MBC) of 2.0 mg/mL. For E. coli, the DIZ was 12.3 mm with MIC and MBC values of 2.0 mg/mL and 4.0 mg/mL, respectively. The SDS-PAGE analysis revealed that some of the electrophoretic bacterial cell proteins bands disappeared with the increase in GEO concentration. Consequently, the nucleic acids content of bacterial suspension was raised significantly and the metabolic activity of bacteria was markedly decreased. GEO could thus inhibit the expression of some genes linked to bacterial energy metabolism, tricarboxylic acid cycle, cell membrane-related proteins, and DNA metabolism. Our findings speculate the bactericidal effects of GEO primarily through disruption of the bacterial cell membrane indicating its suitability in food perseveration.

Download Full-text

Virulence of methicillin-resistant Staphylococcus aureus modulated by the YycFG two-component pathway in a rat model of osteomyelitis

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-019-1508-z ◽

2019 ◽

Vol 14 (1) ◽

Author(s):

Shizhou Wu ◽

Yunjie Liu ◽

Lei Lei ◽

Hui Zhang

Keyword(s):

Staphylococcus Aureus ◽

Western Blot ◽

Rat Model ◽

Biofilm Formation ◽

Bacterial Biofilm ◽

Invasive Ability ◽

Methicillin Resistant ◽

Two Component ◽

Mrsa Strains

Abstract Objectives Methicillin-resistant Staphylococcus aureus (MRSA) strains present an urgent medical problem in osteomyelitis cases. Our previous study indicated that the YycFG two-component regulatory pathway is associated with the bacterial biofilm organization of MRSA strains. The aim of this study was to investigate the regulatory roles of ASyycG in the bacterial biofilm formation and the pathogenicity of MRSA strains using an antisense RNA strategy. Methods An ASyycG-overexpressing MRSA clinical isolate was constructed. The bacterial growth was monitored, and the biofilm biomass on bone specimens was examined using scanning electron microscopy and confocal laser scanning microscopy. Furthermore, quantitative RT-PCR (QRT-PCR) analysis was used to measure the expression of yycF/G/H and icaA/D in the MRSA and ASyycG strains. The expression of the YycG protein was quantified by Western blot assays. We validated the role of ASyycG in the invasive ability and pathogenicity of the strains in vivo using histology and peptide nucleic acid fluorescent in situ hybridization. Results The results showed that overexpression of ASyycG lead to a reduction in biofilm formation and exopolysaccharide (EPS) synthesis compared to the control MRSA strains. The ASyycG strains exhibited decreased expression of the yycF/G/H and icaA/D genes. Furthermore, Western blot data showed that the production of the YycG protein was inhibited in the ASyycG strains. In addition, we demonstrated that ASyycG suppressed the invasive ability and pathogenicity of the strain in vivo using an SPF (specific pathogen free) rat model. Conclusion In summary, the overexpression of ASyycG leads to a reduction in biofilm formation and bacterial pathogenicity in vivo, which provides a potential target for the management of MRSA-induced osteomyelitis.

Download Full-text