scholarly journals The effects of Staphylococcus aureus biofilm conditioned media on 3T3 fibroblasts

FEMS Microbes ◽  
2021 ◽  
Author(s):  
Leigh Madden ◽  
Shyan Huey Low ◽  
Anthony R J Phillips ◽  
Kimberly A Kline ◽  
David L Becker

Abstract Staphylococcus aureus (SA) is the most common bacterial species in chronic wounds. However, there is a lack of understanding of how SA secretions affect the cell biology during the healing process. We studied the effects of biofilm-secretions from SA strain SA29213 on 3T3 fibroblasts. SA29213 is a chronic wound isolate and widely used as a reference strain. We used a series of concentrations of biofilm-conditioned media (BCM) and found 100% BCM is lethal within 10 hours. Cells survived in ≤75% BCM but the rate of closure in scratch wound assays was reduced. Treatment with 75% and 50% BCM caused fibroblasts to change shape and develop dendrite like processes. Prolonged treatment with 75% and 50% BCM, reduced cell proliferation and increased the 4n DNA cell population with cell cycle arrest. There was also an elevation in the senescence marker beta galactosidase and the number of multinucleated cells. Shorter treatments with 75% and 50% SA BCM caused an increase in cell-cell adhesion and a redistribution of β-catenin from the cell membrane to the cytoplasm along with a change in the appearance and decrease in size of ZO-1, vinculin and paxillin structures. Fibroblasts in the edge of chronic wounds exposed to the secretions of SA may suffer similar effects such as induction of senescence, reduced proliferation and migration, which may contribute to the delayed healing of these chronic infected wounds.

2020 ◽  
Author(s):  
Aleksander Mahnic ◽  
Vesna Breznik ◽  
Maja Bombek Ihan ◽  
Maja Rupnik

AbstractChronic wounds are a prominent health concern affecting 0.2% of individuals in the Western population. Microbial colonization and the consequent infection contribute significantly to the healing process of chronic wounds. We have compared cultivation and 16S amplicon sequencing (16S-AS) for the characterization of bacterial populations in swabs and biopsy tissues obtained from 45 chronic wounds and analysed metadata for wound-specific and clinical-outcome-associated correlations with bacterial community structure.Using cultivation approach, we detected a total of 39 bacterial species, on average 2.89 per sample (SD=1.93). Comparison of cultivation results between swabs and biopsy samples showed no significant advantage of one sampling method over the other. 16S-AS was advantageous in comparison to the cultivation approach in case of highly diverse communities, where we could additionally detect numerous obligate and facultative anaerobic bacteria from genera Anaerococcus, Finegoldia, Porphyromonas, Morganella and Providencia. Based on the community diversity, chronic wound microbiota could be distributed into three groups, however, no correlation between groups and clinical outcome was observed. Clinically estimated presence of biofilm and a larger surface area at the initial visit were most significantly associated with unfavourable clinical outcomes after one-year follow-up visit. Corynebacterium was the single most predictive bacterial genus associated with unfavourable clinical outcomes in our study.


Author(s):  
Raza ur Rehman Syed ◽  
Robin augustine ◽  
Alap ali Zahid ◽  
Anwarul Hasan

Non-healing chronic wounds are the key concern in type-2 diabetes that frequently leads to chronic infections, finally causing amputation of limbs, organs etc. Decrease in the proliferation and migration of cells such as keratinocytes and fibroblasts is the major reason for the development of such chronic diabetic wounds. Multiple evidences have shown that CTGF and reduced graphene oxide possesses angiogenic property and promote wound healing by promoting proliferation and migration of fibroblasts and keratinocytes cells.Conjugation of rGO with CTGF using EDC-NHS chemistry is a novel approach to accelerate the wound healing process. In the current work, we have developed a rGO/CTGF incorporated GelMA hydrogel dressing to improve wound healing by increasing proliferation and migration of cells as well as promoting formation of new blood vessels for increased supply of nutrients, oxygen and growth factors to wound area


2015 ◽  
Vol 9 (09) ◽  
pp. 936-944 ◽  
Author(s):  
Shin Yee Wong ◽  
Rishya Manikam ◽  
Sekaran Muniandy

Introduction: Chronic wounds represent a major health burden worldwide. It has been hypothesized that the polymicrobial nature of wounds plays an important role in their healing process. Thus, a review of pathogen frequency and susceptibility patterns in wounds is necessary to provide appropriate guidelines for antimicrobial usage. Methodology: In this study, microbiota and antimicrobial resistance in both acute and chronic wound patients treated at the University of Malaya Medical Centre, Malaysia, were compared. Wound swabs from 84 patients with acute wounds and 84 patients with chronic wounds were collected. The specimens were cultured using standard microbiological techniques. Isolates were then tested for antibiotic sensitivity with the broth microdilution method. Results: Of 210 pathogenic bacteria isolates, Staphylococcus aureus (49; 23.3%) and Pseudomonas aeruginosa (31; 14.8%) were the most prevalent bacteria found in wounds. Staphylococcus aureus was found significantly more often in patients with chronic wounds (41; 48.8%) than in patients with acute wounds (8; 9.5%), while Staphylococcus epidermidis was found predominantly in acute wounds (15; 17.9%). At the time of study, patients with chronic wounds (58.3%) had received more antibiotic treatments in the past previous 12 months compared with patients with acute wounds (16.7%). In the antibiotic susceptibility test, Staphylococcus spp. revealed highest resistance towards penicillin and ampicillin. Isolates showed no decrease in susceptibility against a number of newly developed antibiotics (linezolid, daptomycin, and tigecycline). Conclusions: Our finding showed that bacteria diversity and antimicrobial-resistant strains are more frequently found in chronic wounds than in acute wounds.


2021 ◽  
Vol 8 ◽  
Author(s):  
Aleksander Mahnic ◽  
Vesna Breznik ◽  
Maja Bombek Ihan ◽  
Maja Rupnik

Chronic wounds are a prominent health concern affecting 0.2% of individuals in the Western population. Microbial colonization and the consequent infection contribute significantly to the healing process. We have compared two methods, cultivation and 16S amplicon sequencing (16S-AS), for the characterization of bacterial populations in both swabs and biopsy tissues obtained from 45 chronic wounds. Using cultivation approach, we detected a total of 39 bacterial species, on average 2.89 per sample (SD = 1.93), compared to 5.9 (SD = 7.1) operational taxonomic units per sample obtained with 16S-AS. The concordance in detected bacteria between swab and biopsy specimens obtained from the same CWs was greater when using cultivation (58.4%) as compared to 16S-AS (25%). In the entire group of 45 biopsy samples concordance in detected bacterial genera between 16S-AS and cultivation-based approach was 36.4% and in swab samples 28.7%. Sequencing proved advantageous in comparison to the cultivation mainly in case of highly diverse microbial communities, where we could additionally detect numerous obligate and facultative anaerobic bacteria from genera Anaerococcus, Finegoldia, Porphyromonas, Morganella, and Providencia. Comparing swabs and biopsy tissues we concluded, that neither sampling method shows significant advantage over the other regardless of the method used (16S-AS or cultivation). In this study, chronic wound microbiota could be distributed into three groups based on the bacterial community diversity. The chronic wound surface area was positively correlated with bacterial diversity in swab specimens but not in biopsy tissues. Larger chronic wound surface area was also associated with the presence of Pseudomonas in both biopsy and swab specimens. The presence of Corynebacterium species at the initial visit was the microbial marker most predictive of the unfavorable clinical outcome after one-year follow-up visit.


2017 ◽  
Vol 1 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Besser Manuela ◽  
Khosravani Milad ◽  
Severing Anna-Lena ◽  
Rembe Julian-Dario ◽  
Stuermer Ewa Klara

If a wound progressively heals or the healing process is impaired is basically influenced by the surrounding milieu. This is reflected by the wound fluid. Its specific composition triggers the migration, proliferation and differentiation of dermal and epidermal cells which so far was not sufficiently examined in 2D cell culture models. The influence of the different wound entities was analyzed on a newly implemented three dimensional in-vitro model, which improved the transferability to the in-vivo situation. The influence of pooled wound fluids from patients suffering from acute or chronic wounds were investigated within a time period of 10 days after wound application. Histological and immunohistochemical analyses were performed addressing the impact of AWF and CWF on regeneration, such as cell proliferation, fibroblast activity and cell migration. AWF slightly stimulated fibroblast migration while CWF inhibited their activation and migration. The CXCR4- immunopositive population was continuously decreased compared to the control and AWF treatment. The expression of FAP was enhanced under AWF and medium. In keratinocytes CWF massively stimulated cell proliferation initiating on day six after injury. The presence of 10% CWF inhibited fibroblast activation and migration and induced the degradation of the collagen matrix. Keratinocytes were stimulated to proliferate, resulting in healing inhibiting hyperplasia. Transferred to human wounds, no effective wound closure would be achieved because of the de-regulation of pro-proliferative and migration-stimulating factors and a degraded extracellular matrix. This newly implemented 3D study model represents a novel appropriate in-vitro system for studying healing mechanisms and potential therapeutic applications.


2020 ◽  
Author(s):  
Lungwani Muungo

ADP ribosylation factor GTPase-activating protein 3 (ARFGAP3) is a GTPase-activating protein that associates with the Golgiapparatus and regulates the vesicular trafficking pathway. In the present study, we examined the contribution of ARFGAP3 toprostate cancer cell biology. We showed that ARFGAP3 expression was induced by 100 nM of dihydrotestosterone (DHT) atboth the mRNA and protein levels in androgen-sensitive LNCaP cells. We generated stable transfectants of LNCaP cells withFLAG-tagged ARFGAP3 or a control empty vector and showed that ARFGAP3 overexpression promoted cell proliferation andmigration compared with control cells. We found that ARFGAP3 interacted with paxillin, a focal adhesion adaptor protein thatis important for cell mobility and migration. Small interfering RNA (siRNA)-mediated knockdown of ARFGAP3 showed thatARFGAP3 siRNA markedly reduced LNCaP cell growth. Androgen receptor (AR)-dependent transactivation activity on prostatespecificantigen (PSA) enhancer was synergistically promoted by exogenous ARFGAP3 and paxillin expression, as shown byluciferase assay in LNCaP cells. Thus, our results suggest that ARFGAP3 is a novel androgen-regulated gene that can promoteprostate cancer cell proliferation and migration in collaboration with paxillin.


2020 ◽  
pp. 43-57
Author(s):  
Anna Tabuika

The article reflects the results of a retrospective non-comparative study, the objects of which were 34 outpatient comorbid patients (15 of which are over 60 years old) with chronic wounds of the lower limbs developed against the background of varicosity, post-thrombotic disease, chronic arterial insufficiency of the lower limbs, diabetes mellitus or their combination. Their local treatment was carried out using atraumatic ointment dressing «Branolind N» containing Peruvian balsam. There were 23 women (67.6 %) and 11 men (32.4 %). In microbiological study prior to the beginning of treatment in 31 patients the growth of a pathogen of wound infection was revealed; in 19 patients — Staphylococcus aureus in monoculture and in various associations, in 6 patients — Pseudomonas aeruginosa in monoculture, in other cases — other pathogens. In 3 patients the pathogen was not detected. The average wound size was 34 cm2 . The phase of the wound process was additionally confirmed by cytological studies. After treatment the average area of the wound defect decreased by 10 cm2 and made 24 cm2 on average. Full healing of the wound defect occurred in 11 patients, the others had granulation and active marginal epithelization. There was also a decrease in bacterial semination of wounds, a change in composition of infection agents to less aggressive monoflora, and cytologically — a decrease in signs of inflammation against the background of significant activation of reparative processes.


2020 ◽  
Vol 16 ◽  
Author(s):  
Kuldeep B. Pawar ◽  
Shivani Desai ◽  
Ramesh R. Bhonde ◽  
Ritesh P. Bhole ◽  
Atul A. Deshmukh

: Diabetes is a chronic metabolic disorder of endocrine system characterized by increase in blood glucose level. Several factors such as pancreatic damage, oxidative stress, infection, genetic factor, obesity, liver dysfunction play a vital role in pathogenesis of diabetes which further lead to serious diabetic complications. Diabetic wound is one such complication where the wound formation occurs, especially due to pressure and its healing process is disrupted due to factors such as hyperglycemia, neuropathy, nephropathy, peripheral vascular disease, reduction of blood flow, atherosclerosis, impaired fibroblast. Process of wound healing is delayed due to different abnormalities like alteration in nitric oxide level, increase in aldose reductase, sorbitol and fructose. Therefore, diabetic wound requires more time to heal as compare to normal wound. Healing time is delayed in diabetic wound due to many factors such as stress, decreased oxygenation supply, infection, decreased blood flow, impaired proliferation and migration rate, impaired growth factor production, impaired keratinocytes proliferation and migration, and altered vascular endothelial mediators. The current treatment for diabetic wound includes wound patches, oxygenation therapy, hydrogel patches, gene therapy, laser therapy, and stem cell therapy. Medications with phytoconstituents is also one way to manage diabetic wound, but it is not more effective for quick healing. The objective of this review is to understand the potential of various management options which are available for diabetic wound, with a special focus on biological cells.


2021 ◽  
Vol 22 (9) ◽  
pp. 4297
Author(s):  
Matthew Thomas Ferreira ◽  
Juliano Andreoli Miyake ◽  
Renata Nascimento Gomes ◽  
Fábio Feitoza ◽  
Pollyana Bulgarelli Stevannato ◽  
...  

Prostaglandin E2 (PGE2) is known to increase glioblastoma (GBM) cell proliferation and migration while cyclooxygenase (COX) inhibition decreases proliferation and migration. The present study investigated the effects of COX inhibitors and PGE2 receptor antagonists on GBM cell biology. Cells were grown with inhibitors and dose response, viable cell counting, flow cytometry, cell migration, gene expression, Western blotting, and gelatin zymography studies were performed. The stimulatory effects of PGE2 and the inhibitory effects of ibuprofen (IBP) were confirmed in GBM cells. The EP2 and EP4 receptors were identified as important mediators of the actions of PGE2 in GBM cells. The concomitant inhibition of EP2 and EP4 caused a significant decrease in cell migration which was not reverted by exogenous PGE2. In T98G cells exogenous PGE2 increased latent MMP2 gelatinolytic activity. The inhibition of COX1 or COX2 caused significant alterations in MMP2 expression and gelatinolytic activity in GBM cells. These findings provide further evidence for the importance of PGE2 signalling through the EP2 and the EP4 receptor in the control of GBM cell biology. They also support the hypothesis that a relationship exists between COX1 and MMP2 in GBM cells which merits further investigation as a novel therapeutic target for drug development.


Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1182
Author(s):  
Claudia Ramirez-Sanchez ◽  
Francis Gonzales ◽  
Maureen Buckley ◽  
Biswajit Biswas ◽  
Matthew Henry ◽  
...  

Successful joint replacement is a life-enhancing procedure with significant growth in the past decade. Prosthetic joint infection occurs rarely; it is a biofilm-based infection that is poorly responsive to antibiotic alone. Recent interest in bacteriophage therapy has made it possible to treat some biofilm-based infections, as well as those caused by multidrug-resistant pathogens, successfully when conventional antibiotic therapy has failed. Here, we describe the case of a 61-year-old woman who was successfully treated after a second cycle of bacteriophage therapy administered at the time of a two-stage exchange procedure for a persistent methicillin-sensitive Staphylococcus aureus (MSSA) prosthetic knee-joint infection. We highlight the safety and efficacy of both intravenous and intra-articular infusions of bacteriophage therapy, a successful outcome with a single lytic phage, and the development of serum neutralization with prolonged treatment.


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