scholarly journals Controlling Staphylococcus aureus by 2-[(Methylamino)methyl]phenol (2-MAMP) in a co-culture moderates the biofilm and virulence of Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Gopalakrishan Thamil Selvan ◽  
Brindha Thirunavukkarasu ◽  
Nerellapalli Nandini Pravallika ◽  
Sahana Vasudevan ◽  
Balamurugan Palaniappan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Chronic Wound ◽  
Healing Process ◽  
Relative Increase ◽  
Polymicrobial Infection ◽  
Wound Healing Process ◽  
Polymicrobial Infections ◽  
Chronic Wound Infection

Staphylococcus aureus and Pseudomonas aeruginosa are the most encountered organisms in a polymicrobial chronic wound infection. Production of multiple virulence factors by this duo delays wound healing process. Notably P. aeruginosa displays enhanced virulence in the presence of S. aureus by a peptidoglycan sensing mechanism. Thus novel therapies are imperative to address polymicrobial infections effectively. Previously, it has been suggested that targeting S. aureus might be a possible approach to reduce the severity of P. aeruginosa in a polymicrobial infection. In this aspect, we have used 2-[(Methylamino)methyl]phenol (2-MAMP), our previously reported QS inhibitor to target S. aureus and phenotypically determine the virulence factors of P. aeruginosa under this condition. Analysis of major virulence factors of Pseudomonas viz. biofilm, pyocyanin and pyoveridine showed a significant reduction. The competitive index (CI) and relative increase ratio (RIR) were determined to understand the organisms interaction in co-culture. Results indicated competitiveness among the strains and on increasing ratios of S. aureus cells, co-existence was noticed. Further as a sensible approach antibiotic anti-virulence drug combinations were tested on co-culture. Significant improvement in the growth inhibition was observed. Our preliminary results presented here would enable further research to address polymicrobial infection in a novel way.

scholarly journals The inhibitory effects of Staphylococcus aureus on the antibiotic susceptibility and virulence factors of Pseudomonas aeruginosa: A549 cell line model

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sanaz Dehbashi ◽  
Mohammad Yousef Alikhani ◽  
Hamed Tahmasebi ◽  
Mohammad Reza Arabestani
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Cell Line ◽  
Virulence Factors ◽  
A549 Cell ◽  
Virulent Strain ◽  
Inhibitory Effect ◽  
A549 Cell Line ◽  
Polymicrobial Infections

AbstractPseudomonas aeruginosa and Staphylococcus aureus often lead to serious lung infections. This study aimed to investigate the role of S. aureus in the expression of the β-lactamase enzymes and virulence factors of P. aeruginosa in the polymicrobial infections of the respiratory tract. Biofilm and planktonic co-culture of P. aeruginosa and S. aureus were performed in the A549 cell line. Then, antibiotic resistance and virulence factors of P. aeruginosa were examined, and the expression of lasR, lasI, algD, mexR, and KPC genes were determined using qPCR. S.aureus decreased β-lactam resistance but increased resistance to tobramycin in the biofilm condition. Furthermore, S.aureus showed a positive effect on reducing resistance to meropenem, doripenem, and tobramycin (except PA-2). Altough it was demonstrated that S.aureus reduced the viability of P. aeruginosa, particularly in the biofilm state, the pathogenicity of the recovered strains of P.aeruginosa increased. Moreover, the gene expression levels for lasR/I and algD were increased in biofilm conditions. The levels of lasI were more prominent in the virulent strain than the β-lactamase producing strain. Furthermore, the expression of KPC was increased in all strains of P. aeruginosa. According to the findings of this study, S. aureus has an inhibitory effect in polymicrobial infections by suppressing the β-lactamase genes and viability of P. aeruginosa. Also, it cooperates with the biofilm-producing P. aeruginosa strains to increase pathogenicity and resistance to tobramycin.

A Comprehensive Review On Alginate As Wound Dressing Biomaterial

2020 ◽  
Vol 04 ◽  
Author(s):  
Sourav Mohanto ◽  
Prithviraj Chakraborty ◽  
Chidambaram Soundra Pandian ◽  
Shubhradeep Manna ◽  
Joni Dutta
Keyword(s):  
Therapeutic Efficacy ◽  
Wound Dressing ◽  
Chronic Wound ◽  
Healing Process ◽  
Wound Healing Process ◽  
Detailed Knowledge ◽  
Pathophysiological Mechanisms ◽  
Moist Environment ◽  
Bioactive Agents ◽  
Mechanical Nature

Background: The design and characteristics of alginate biomaterial have a significant role in wound dressing and tissue regeneration. The ideal biomaterial for wound dressing must have biodegradable, biocompatible, non-inflammatory, non-toxic. Objective: Wound dressing should promote the re-epithelization and protect the wound for further infection by creating a moist environment. The physical and mechanical nature of the alginate biopolymer has the potential to influence the pathophysiological mechanisms in the chronic wound actively. The application of this biomaterial provides an ampule advantage to synthetic polymers. Method: The wound healing process is a critical step involved in different phases. The presence of cross-linkers, polymers along with alginate lead to a decrease in the mechanical property of dressing. Hence the effective material choosing along with alginate is a very critical decision. The therapeutic efficacy of the alginate dressing system (film, hydrogel, wafer, etc.) influenced by the incorporation of different materials such as bioactive agents, nanoparticles, cross-linker, nature of the excipients, etc. Results: The ion exchange occurring between dressing and exudates resulted in the formation of gel, due to the glucuronic acid presence in alginate. This gel absorbs moisture and maintains an appropriate moist environment and actively influence the pathophysiological mechanisms in the chronic wound. Conclusion: This review gives a detailed knowledge of the researchers to work with alginate and provides knowledge about the incorporation of the appropriate material and their therapeutic efficacy in wound dressing.

New Strategies Targeting Virulence Factors of Staphylococcus aureus and Pseudomonas aeruginosa

2017 ◽  
Vol 38 (03) ◽  
pp. 346-358 ◽  
Author(s):  
Bruno François ◽  
Charles-Edouard Luyt ◽  
C. Stover ◽  
Jeffery Brubaker ◽  
Jean Chastre ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Effective Utilization ◽  
Mechanically Ventilated ◽  
Stage Of Development ◽  
Antivirulence Agents ◽  
Interventional Therapies ◽  
Improve Patient ◽  
New Strategies

AbstractMorbidity, mortality, and economic burden of nosocomial pneumonia caused by Staphylococcus aureus and Pseudomonas aeruginosa remain high in mechanically ventilated and hospitalized patients despite the use of empirical antibiotic therapy or antibiotics against specific classes of pathogens and procedures to reduce nosocomial infections in hospital settings. Newer agents that neutralize or inhibit specific S. aureus or P. aeruginosa virulence factors may eliminate or reduce the risk for developing pneumonia before or during mechanical ventilation and may improve patient outcomes through mechanisms that differ from those of antibiotics. In this article, we review the types, mechanisms of action, potential advantages, and stage of development of antivirulence agents (AVAs) that hold promise as alternative preventive or interventional therapies against S. aureus– and P. aeruginosa–associated nosocomial pneumonias. We also present and discuss challenges to the effective utilization of AVAs separately from or in addition to antibiotics and the design of clinical trials and meaningful study end points.

Human-microorganism mutualism theory: Possible mechanisms for the delayed chronic wound healing process

2020 ◽  
Vol 141 ◽  
pp. 109720
Author(s):  
Mengru Pang ◽  
Zexin Yao ◽  
Caihong Chen ◽  
Xiaoxuan Lei ◽  
Biao Cheng
Keyword(s):  
Wound Healing ◽  
Chronic Wound ◽  
Healing Process ◽  
Wound Healing Process

scholarly journals Functional Mining of the Crotalus Spp. Venom Protease Repertoire Reveals Potential for Chronic Wound Therapeutics

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3401
Author(s):  
David Meléndez-Martínez ◽  
Luis Fernando Plenge-Tellechea ◽  
Ana Gatica-Colima ◽  
Martha Sandra Cruz-Pérez ◽  
José Manuel Aguilar-Yáñez ◽  
...  
Keyword(s):  
Wound Healing ◽  
Serine Proteases ◽  
Chronic Wounds ◽  
Chronic Wound ◽  
Healing Process ◽  
Wound Healing Process ◽  
Major Health Problem ◽  
Normal Wound Healing ◽  
Alternative Sources ◽  
Fibrin Clots

Chronic wounds are a major health problem that cause millions of dollars in expenses every year. Among all the treatments used, active wound treatments such as enzymatic treatments represent a cheaper and specific option with a fast growth category in the market. In particular, bacterial and plant proteases have been employed due to their homology to human proteases, which drive the normal wound healing process. However, the use of these proteases has demonstrated results with low reproducibility. Therefore, alternative sources of proteases such as snake venom have been proposed. Here, we performed a functional mining of proteases from rattlesnakes (Crotalus ornatus, C. molossus nigrescens, C. scutulatus, and C. atrox) due to their high protease predominance and similarity to native proteases. To characterize Crotalus spp. Proteases, we performed different protease assays to measure and confirm the presence of metalloproteases and serine proteases, such as the universal protease assay and zymography, using several substrates such as gelatin, casein, hemoglobin, L-TAME, fibrinogen, and fibrin. We found that all our venom extracts degraded casein, gelatin, L-TAME, fibrinogen, and fibrin, but not hemoglobin. Crotalus ornatus and C. m. nigrescens extracts were the most proteolytic venoms among the samples. Particularly, C. ornatus predominantly possessed low molecular weight proteases (P-I metalloproteases). Our results demonstrated the presence of metalloproteases capable of degrading gelatin (a collagen derivative) and fibrin clots, whereas serine proteases were capable of degrading fibrinogen-generating fibrin clots, mimicking thrombin activity. Moreover, we demonstrated that Crotalus spp. are a valuable source of proteases that can aid chronic wound-healing treatments.

scholarly journals Hypertonic glucose inhibits growth and attenuates virulence factors of multidrug-resistant Pseudomonas aeruginosa

2020 ◽  
Author(s):  
Tao Chen ◽  
Ye Xu ◽  
Wenya Xu ◽  
Wenli Liao ◽  
Chunquan Xu ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Diabetic Foot ◽  
Biofilm Formation ◽  
Chronic Wound ◽  
Multidrug Resistant ◽  
Wound Infections ◽  
Hypertonic Glucose ◽  
Diabetic Foot Infections ◽  
Chronic Wound Infections

Abstract Background: Pseudomonas aeruginosa is the most common Gram-negative pathogen responsible for chronic wound infections, such as diabetic foot infections, and further exacerbates the treatment options and cost of such conditions. Hypertonic glucose, a commonly used prolotherapy solution, can accelerate the proliferation of granulation tissue and improve microcirculation in wounds. However, the action of hypertonic glucose on bacterial pathogens that infect wounds is unclear. In this study, we investigated the inhibitory effects of hypertonic glucose on multidrug-resistant P. aeruginosa strains isolated from diabetic foot infections. Hypertonic glucose represents a novel approach to control chronic wound infections caused by P. aeruginosa. Results: Four multidrug-resistant P. aeruginosa clinical strains isolated from diabetic foot ulcers from a tertiary hospital in China and the reference P. aeruginosa PAO1 strain were studied. Hypertonic glucose significantly inhibited the growth, biofilm formation, and swimming motility of P. aeruginosa clinical strains and PAO1. Furthermore, hypertonic glucose significantly reduced the production of pyocyanin and elastase virulence factors in P. aeruginosa. The expression of major quorum sensing genes (lasI, lasR, rhlI, and rhlR) in P. aeruginosa were all downregulated in response to hypertonic glucose treatment. In a Galleria mellonella larvae infection model, the administration of hypertonic glucose was shown to increase the survival rates of larvae infected by P. aeruginosa strains (3/5).Conclusions: Hypertonic glucose inhibited the growth, biofilm formation, and swimming motility of P. aeruginosa, as well as reduced the production of virulence factors and quorum sensing gene expression. Further studies that investigate hypertonic glucose therapy should be considered in treating chronic wound infections.

scholarly journals The Effect Of Giving Honey on The Process of Wound Healing in Burned Patients

2021 ◽  
Vol 5 (1) ◽  
pp. 51-56
Author(s):  
Intan Pramesty
Keyword(s):  
Staphylococcus Aureus ◽  
Wound Healing ◽  
Healing Process ◽  
Health Sector ◽  
Antimicrobial Properties ◽  
High Viscosity ◽  
Low Ph ◽  
Wound Healing Process ◽  
Burn Patients ◽  
Ph Level

Backgroud: Burns are one of the most dangerous injuries and the main cause of disability to death. Burns can be interpreted as one of the serious problems in society and are recorded to cause around 265,000 deaths each year. Honey can maintain the wound condition to keep it moist and in high viscosity to prevent infection. Method: This study was conducted to determine the effect of honey on the wound healing process in burn patients. This study uses a literature review method. The population in this study is a journal with a background in the health sector with 10 international journals on burns with the qualifications of 9 SCIMAGO indexed journals and 1 SINTA indexed journal published from 2015 to 2020. Results: Burns that treated in the form of pure honey can generate good results and heal in an average of 20 days. The healing process will be better, if the wound given a mixture of other ingredients which also have a low acidity such as garlic, chitosan and beeswax and olive oil. Honey has antimicrobial properties and a low pH level. The microbe most sensitive to honey is Staphylococcus aureus. Conclusion: The conclusion from this study, honey can be used as an alternative treatment for burns.

scholarly journals Genotypic and phenotypic diversity of Staphylococcus aureus from cystic fibrosis lung infections and their interactions with Pseudomonas aeruginosa

2019 ◽  
Author(s):  
Eryn E. Bernardy ◽  
Robert A. Petit ◽  
Vishnu Raghuram ◽  
Ashley M. Alexander ◽  
Timothy D. Read ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Phenotypic Diversity ◽  
Laboratory Strain ◽  
Toxin Production ◽  
Reference Isolate ◽  
Patient Health ◽  
Lung Infections

AbstractPseudomonas aeruginosa and Staphylococcus aureus are the most common bacteria that infect the respiratory tract of individuals with the genetic disease cystic fibrosis (CF); in fact, S. aureus has recently overtaken P. aeruginosa to become the most common. Substantial research has been performed on the epidemiology of S. aureus in CF; however, there appears to be a gap in knowledge in regard to the pathogenesis of S. aureus in the context of CF lung infections. Most studies have focused on a few S. aureus isolates, often exclusively laboratory adapted strains, and how they are killed by P. aeruginosa. Because of this, little is known about the diversity of S. aureus CF lung isolates in both virulence and interaction with P. aeruginosa. To begin to address this gap in knowledge, we recently sequenced 65 clinical S. aureus isolates from the Emory CF Biospecimen Registry and Boston Children’s Hospital, including the reference isolate JE2, a USA300 strain. Here, we analyzed antibiotic resistance genotypes, sequence type, clonal complex, spa type, and agr type of these isolates. We hypothesized that major virulence phenotypes of S. aureus that may be associated with CF lung infections, namely toxin production and mucoid phenotype, would be retained in these isolates. To test our hypothesis, we plated on specific agars and found that most isolates can hemolyze both rabbit and sheep blood (67.7%) and produce polysaccharide (69.2%), consistent with virulence retention in CF lung isolates. We also identified three distinct phenotypic groups of S. aureus based on their survival in the presence of nonmucoid P. aeruginosa laboratory strain PAO1 and its mucoid derivative. Altogether, our work provides greater insight into the diversity of S. aureus CF isolates, specifically the distribution of important virulence factors and their interaction with P. aeruginosa, all of which have implications in patient health.Author SummaryStaphylococcus aureus is now the most frequently detected pathogen in the lungs of individuals who have cystic fibrosis (CF), followed closely by Pseudomonas aeruginosa. When these two pathogens are found to coinfect the CF lung, patients have a significantly worse prognosis. While P. aeruginosa has been rigorously studied in the context of bacterial pathogenesis in CF, less is known about S. aureus. Here we present an in-depth study of 64 S. aureus CF clinical isolates where we investigated genetic diversity utilizing whole genome sequencing, virulence phenotypes, and interactions with P. aeruginosa. We have found that S. aureus isolated from the CF lung are phylogenetically diverse, most retain known virulence factors, and they vary in interactions with P. aeruginosa from highly sensitive to completely tolerant. Deepening our understanding of how S. aureus responds to its environment and other microbes in the CF lung will enable future development of effective treatments and preventative measures against these formidable infections.

scholarly journals Antibacterial Test of Binahong Leaf Extract Ointment (Anredera cordifolia) Against Staphylococcus aureus Bacteria from Diabetic Wounds

2020 ◽  
Vol 5 (01) ◽  
pp. 1-10
Author(s):  
Risa Umami ◽  
Riwayati Malika
Keyword(s):  
Staphylococcus Aureus ◽  
Wound Healing ◽  
Leaf Extract ◽  
Wound Closure ◽  
Healing Process ◽  
The Body ◽  
Wound Healing Process ◽  
Antibacterial Test ◽  
Glucose Levels ◽  
Diabetic Wounds

Diabetes mellitus (DM) is characterized by an increase in glucose levels in the blood due to disorders of glucose metabolism in the body. The pancreas organ of people with DM has a weakness in producing the hormone insulin. As a result, the distribution of blood glucose to other organs of the body is inhibited so that glucose levels in the blood increase which causes DM sufferers to experience longer wound healing than normal humans. Binahong leaves contain alkaloids, saponins and flavonoids which have antibacterial activity which can accelerate the wound healing process. The purpose of this study was to determine the antibacterial effect of binahong leaf extract ointment (Anredera cordifolia) against Staphylococcus aureus bacteria from diabetic wounds. This research includes antibacterial test for binahong leaf extract ointment (Anredera cordifolia) with variations in the concentration of 10%, 20%, and 30% of the concentration of binahong leaf extract of 25% which resulted in a wound coverage percentage of up to 100%, namely at 30% ointment concentration. The conclusion of this study is that there was no wound closure for negative control and positive control in the form of oxytetracycline, the percentage of wound closure was 85%.

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