scholarly journals Antibacterial and Anti-biofilm Efficacy of Chinese Dragon’s Blood Against Staphylococcus aureus Isolated From Infected Wounds

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiangkuo Zheng ◽  
Lijiang Chen ◽  
Weiliang Zeng ◽  
Wenli Liao ◽  
Zhongyong Wang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Membrane ◽  
Biofilm Formation ◽  
Empiric Therapy ◽  
Sem Analysis ◽  
Clinical Settings ◽  
Expression Levels ◽  
Dragon’S Blood ◽  
Infected Wounds ◽  
Time Kill

Chinese dragon’s blood (CDB), a characteristic red resin, is an important traditional Chinese medicine (TCM), and empiric therapy of infected wounds with CDB is performed in clinical settings. For the first time, we herein report the antibacterial and anti-biofilm efficacy of CDB against Staphylococcus aureus (S. aureus). Antimicrobial susceptibility testing, growth curve assay, time-kill curve assay, crystal violet biofilm assay, scanning electron microscope (SEM) analysis, cell membrane tests, and quantitative real-time polymerase chain reaction (qRT-PCR) were used for this purpose. The results suggested that the minimum inhibitory concentration (MIC) values of CDB against S. aureus ranged from 32 to 128 μg/mL. Growth curves and time-kill curves confirmed that CDB could inhibit the growth of S. aureus. The biofilm formation ability and the expression levels of saeR, saeS, and hla of S. aureus in the presence and absence of CDB were statistically significant (P < 0.01). The results of SEM analysis and cell membrane tests revealed that exposure to CDB had some destructive effects on S. aureus cells. In conclusion, CDB exhibits positive antibacterial activity against S. aureus. Moreover, CDB could reduce the biofilm formation and the virulence factors of S. aureus by downregulating the expression levels of saeR, saeS, and hla genes. These findings indicated that CDB has immense potential to serve as a viable alternative for the treatment of infected wounds caused by S. aureus in clinical settings.

scholarly journals Alpha-Toxin Is Required for Biofilm Formation by Staphylococcus aureus

2003 ◽  
Vol 185 (10) ◽  
pp. 3214-3217 ◽  
Author(s):  
Nicky C. Caiazza ◽  
G. A. O'Toole
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Clinical Settings ◽  
Alpha Toxin ◽  
Flow Conditions ◽  
Alpha Hemolysin ◽  
Integral Role ◽  
Hemolytic Toxin ◽  
Plastic Surfaces

ABSTRACT Staphylococcus aureus is a common pathogen associated with nosocomial infections. It can persist in clinical settings and gain increased resistance to antimicrobial agents through biofilm formation. We have found that alpha-toxin, a secreted, multimeric, hemolytic toxin encoded by the hla gene, plays an integral role in biofilm formation. The hla mutant was unable to fully colonize plastic surfaces under both static and flow conditions. Based on microscopy studies, we propose that alpha-hemolysin is required for cell-to-cell interactions during biofilm formation.

scholarly journals Control of Foodborne Staphylococcus aureus by Shikonin, a Natural Extract

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2954
Author(s):  
Yangli Wan ◽  
Xiaowen Wang ◽  
Pengfei Zhang ◽  
Meng Zhang ◽  
Mingying Kou ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Cell Membrane ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Food Poisoning ◽  
Heat Stability ◽  
Natural Food ◽  
Foodborne Infection

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.

scholarly journals The Bactericidal and Antibiofilm Activity of Stem Bark of Jatropha multifida L. Against Staphylococcus aureus and MRSA

2018 ◽  
Vol 18 (1) ◽  
pp. 42-55
Author(s):  
Annisa Fitria
Keyword(s):  
Staphylococcus Aureus ◽  
Bactericidal Activity ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Stem Bark ◽  
Antibiofilm Activity ◽  
Biofilm Production ◽  
Bioactive Substance ◽  
Time Kill ◽  
Jatropha Multifida

Chronical wound often caused by bacteria which has antibiotic resistance characteristic and presence of biofilm formation. This study aims to evaluate the bactericidal and antibiofilm activity of stem bark of Jatropha multifida L. against Staphylococcus aureus and MRSA (Methicillin-Resistant Staphylococcus aureus), as alternative antimicrobial agents. Examination of bactericidal activity of the extract was performed by time-kill assay to determine the speed of the extract to eradicate bacteria. The inhibitory activity of extract toward biofilm production was quantified using spectrophotometric method. The extract showed bactericidal activity which can be achieved at 8 hours and 12 hours against Staphylococcus aureus and MRSA in MBC value of 0.5 mg/mL and 1 mg/mL. The extract exhibited antibiofilm activity which indicates by its IC50 value of 0.3 mg/mL and 0.76 mg/mL against Staphylococcus aureus and MRSA. These experiments have shown the potential of the extract of  Jatropha multifida L. stem bark as a bioactive substance in a topical agent for chronical skin infection.  

scholarly journals Effect of ZnO nanoparticles on methicillin, vancomycin, linezolid resistance and biofilm formation in Staphylococcus aureus isolates

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Wedad M. Abdelraheem ◽  
Rasha M. M. Khairy ◽  
Alaa I. Zaki ◽  
Shaimaa H. Zaki
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Genes ◽  
Biofilm Formation ◽  
Formation Rate ◽  
Microtiter Plate ◽  
Multidrug Resistant ◽  
P Value ◽  
Burn Wound ◽  
Zno Nps ◽  
Expression Levels

Abstract Background Multidrug resistant (MDR) and biofilm producing Staphylococcus aureus strains are usually associated with serious infections. This study aimed to evaluate the antibacterial and antibiofilm-formation effects of zinc oxide nanoparticles (ZnO-NPs) against staphylococcus aureus (S. aureus) isolates. Methods A total of 116 S. aureus isolates were recovered from 250 burn wound samples. The antimicrobial/antibiofilm effects of ZnO-NPs against methicillin, vancomycin and linezolid resistant S. aureus (MRSA, VRSA and LRSA) isolates were examined using phenotypic and genotypic methods. The minimum inhibitory concentration (MIC) of ZnO-NPs was determined by microdilution method. The effects of sub-MIC concentrations of ZnO-NPs on biofilm formation and drug resistance in S. aureus were determined by the microtiter plate method. The change in the expression levels of the biofilm encoding genes and resistance genes in S. aureus isolates after treatment with ZnO-NPs was assessed by real time reverse transcriptase PCR (rt-PCR). Results MICs of ZnO-NPs in S. aureus isolates were (128–2048 µg/ml). The sub-MIC of ZnO-NPs significantly reduced biofilm formation rate (the highest inhibition rate was 76.47% at 1024  µg/ml) and the expression levels of biofilm genes (ica A, ica D and fnb A) with P < 0.001. Moreover, Sub-MIC of ZnO-NPs significantly reduced the rates of MRSA from 81.9 (95 isolates) to 13.30% (15 isolates), VRSA from 33.60 (39 isolates) to 0% and LARSA from 29.30 (34) to 0% as well as the expression levels of resistance genes (mec A, van A and cfr) with P value < 0.001. Conclusion ZnO-NPs can be used as antibiofilm and potent antimicrobial against MRSA, VRSA and LRSA isolates.

Biological Evaluation of Selected 1,2,3-triazole Derivatives as Antibacterial and Antibiofilm Agents

2020 ◽  
Vol 20 (24) ◽  
pp. 2186-2191
Author(s):  
Lialyz Soares Pereira André ◽  
Renata Freire Alves Pereira ◽  
Felipe Ramos Pinheiro ◽  
Aislan Cristina Rheder Fagundes Pascoal ◽  
Vitor Francisco Ferreira ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Public Health Problem ◽  
Biological Evaluation ◽  
Major Public Health Problem ◽  
Community Environments ◽  
Scanning Electron

Background: Resistance to antimicrobial agents is a major public health problem, being Staphylococcus aureus prevalent in infections in hospital and community environments and, admittedly, related to biofilm formation in biotic and abiotic surfaces. Biofilms form a complex and structured community of microorganisms surrounded by an extracellular matrix adhering to each other and to a surface that gives them even more protection from and resistance against the action of antimicrobial agents, as well as against host defenses. Methods: Aiming to control and solve these problems, our study sought to evaluate the action of 1,2,3- triazoles against a Staphylococcus aureus isolate in planktonic and in the biofilm form, evaluating the activity of this triazole through Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests. We have also performed cytotoxic evaluation and Scanning Electron Microscopy (SEM) of the biofilms under the treatment of the compound. The 1,2,3-triazole DAN 49 showed bacteriostatic and bactericidal activity (MIC and MBC 128 μg/mL). In addition, its presence interfered with the biofilm formation stage (1/2 MIC, p <0.000001) and demonstrated an effect on young preformed biofilm (2 MICs, p <0.05). Results: Scanning Electron Microscopy images showed a reduction in the cell population and the appearance of deformations on the surface of some bacteria in the biofilm under treatment with the compound. Conclusion: Therefore, it was possible to conclude the promising anti-biofilm potential of 1,2,3-triazole, demonstrating the importance of the synthesis of new compounds with biological activity.

Comparative Time-Kill Study of Doxycycline, Tigecycline, Cefazolin and Vancomycin Against Several Clones of Staphylococcus aureus

2013 ◽  
Vol 8 (4) ◽  
pp. 332-339 ◽  
Author(s):  
Melina Herrera ◽  
Liliana Mobilia ◽  
Graciela Posse ◽  
Adriana Limansky ◽  
Viviana Ballerini ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Time Kill

scholarly journals Interaction of Acinetobacter baumannii with Human Serum Albumin: Does the Host Determines the Outcome?

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 833
Author(s):  
Camila Pimentel ◽  
Casin Le ◽  
Marisel R. Tuttobene ◽  
Tomas Subils ◽  
Krisztina M. Papp-Wallace ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Human Serum Albumin ◽  
Quorum Sensing ◽  
Serum Albumin ◽  
Human Serum ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Model Systems ◽  
Expression Levels ◽  
Multiple Drugs

Acinetobacter baumannii has become a serious threat to human health due to its extreme antibiotic resistance, environmental persistence, and capacity to survive within the host. Two A. baumannii strains, A118 and AB5075, commonly used as model systems, and three carbapenem-resistant strains, which are becoming ever more dangerous due to the multiple drugs they can resist, were exposed to 3.5% human serum albumin (HSA) and human serum (HS) to evaluate their response with respect to antimicrobial resistance, biofilm formation, and quorum sensing, all features responsible for increasing survival and persistence in the environment and human body. Expression levels of antibiotic resistance genes were modified differently when examined in different strains. The cmlA gene was upregulated or downregulated in conditions of exposure to 3.5% HSA or HS depending on the strain. Expression levels of pbp1 and pbp3 tended to be increased by the presence of HSA and HS, but the effect was not seen in all strains. A. baumannii A118 growing in the presence of HS did not experience increased expression of these genes. Aminoglycoside-modifying enzymes were also expressed at higher or lower levels in the presence of HSA or HS. Still, the response was not uniform; in some cases, expression was enhanced, and in other cases, it was tapered. While A. baumannii AB5075 became more susceptible to rifampicin in the presence of 3.5% HSA or HS, strain A118 did not show any changes. Expression of arr2, a gene involved in resistance to rifampicin present in A. baumannii AMA16, was expressed at higher levels when HS was present in the culture medium. HSA and HS reduced biofilm formation and production of N-Acyl Homoserine Lactone, a compound intimately associated with quorum sensing. In conclusion, HSA, the main component of HS, stimulates a variety of adaptative responses in infecting A. baumannii strains.

Sign in / Sign up

Export Citation Format

Share Document