scholarly journals Biofilm and Equine Limb Wounds

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2825
Author(s):  
Elin Jørgensen ◽  
Thomas Bjarnsholt ◽  
Stine Jacobsen

In chronic wounds in humans, biofilm formation and wound chronicity are linked, as biofilms contribute to chronic inflammation and delayed healing. Biofilms are aggregates of bacteria, and living as biofilms is the default mode of bacterial life; within these aggregates, the bacteria are protected from both antimicrobial substances and the immune response of the host. In horses, delayed healing is more commonly seen in limb wounds than body wounds. Chronic inflammation and hypoxia are the main characteristics of delayed wound healing in equine limbs, and biofilms might also contribute to this healing pattern in horses. However, biofilm formation in equine wounds has been studied to a very limited degree. Biofilms have been detected in equine traumatic wounds, and recent experimental models have shown that biofilms protract the healing of equine limb wounds. Detection of biofilms within wounds necessitates advanced techniques that are not available in routine diagnostic yet. However, infections with biofilm should be suspected in equine limb wounds not healing as expected, as they are in human wounds. Treatment should be based on repeated debridement and application of topical antimicrobial therapy.

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 98
Author(s):  
Carla L. Vidal ◽  
Izabela Ferreira ◽  
Paulo S. Ferreira ◽  
Mariana L. C. Valente ◽  
Ana B. V. Teixeira ◽  
...  

Biofilm formation on biomaterials is a challenge in the health area. Antimicrobial substances based on nanomaterials have been proposed to solve this problem. The aim was to incorporate nanostructured silver vanadate decorated with silver nanoparticles (β-AgVO3) into dental porcelains (IPS Inline and Ex-3 Noritake), at concentrations of 2.5% and 5%, and evaluate the surface characteristics (by SEM/EDS), antimicrobial activity (against Streptococcus mutans, Streptococcus sobrinus, Aggregatibacter actinomycetemcomitans, and Pseudomonas aeruginosa), silver (Ag+) and vanadium (V4+/V5+) ions release, and mechanical properties (microhardness, roughness, and fracture toughness). The β-AgVO3 incorporation did not alter the porcelain’s components, reduced the S. mutans, S. sobrinus and A. actinomycetemcomitans viability, increased the fracture toughness of IPS Inline, the roughness for all groups, and did not affect the microhardness of the 5% group. Among all groups, IPS Inline 5% released more Ag+, and Ex-3 Noritake 2.5% released more V4+/V5+. It was concluded that the incorporation of β-AgVO3 into dental porcelains promoted antimicrobial activity against S. mutans, S. sobrinus, and A. actinomycetemcomitans (preventing biofilm formation), caused a higher release of vanadium than silver ions, and an adequate mechanical behavior was observed. However, the incorporation of β-AgVO3 did not reduce P. aeruginosa viability and increased the surface roughness of dental porcelains.


2012 ◽  
Vol 6 (2) ◽  
pp. 17 ◽  
Author(s):  
Masachika Senba ◽  
Naoki Mori

Human papillomavirus (HPV) has developed strategies to escape eradication by innate and adaptive immunity. Immune response evasion has been considered an important aspect of HPV persistence, which is the main contributing factor leading to HPV-related cancers. HPV-induced cancers expressing viral oncogenes E6 and E7 are potentially recognized by the immune system. The major histocompatibility complex (MHC) class I molecules are patrolled by natural killer cells and CD8<sup>+</sup> cytotoxic T lymphocytes, respectively. This system of recognition is a main target for the strategies of immune evasion deployed by viruses. The viral immune evasion proteins constitute useful tools to block defined stages of the MHC class I presentation pathway, and in this way HPV avoids the host immune response. The long latency period from initial infection to persistence signifies that HPV evolves mechanisms to escape the immune response. It has now been established that there are oncogenic mechanisms by which E7 binds to and degrades tumor suppressor Rb, while E6 binds to and inactivates tumor suppressor p53. Therefore, interaction of p53 and pRb proteins can give rise to an increased immortalization and genomic instability. Overexpression of NF-kB in cervical and penile cancers suggests that NF-kB activation is a key modulator in driving chronic inflammation to cancer. HPV oncogene-mediated suppression of NF-kB activity contributes to HPV escape from the immune system. This review focuses on the diverse mechanisms of the virus immune evasion with HPV that leads to chronic inflammation and cancer.


2019 ◽  
Author(s):  
Caitlin N. Esoda ◽  
Meta J. Kuehn

AbstractPseudomonas aeruginosa, known as one of the leading causes of morbidity and mortality in cystic fibrosis (CF) patients, secretes a variety of virulence-associated proteases. These enzymes have been shown to contribute significantly toP. aeruginosapathogenesis and biofilm formation in the chronic colonization of CF patient lungs, as well as playing a role in infections of the cornea, burn wounds and chronic wounds. Our lab has previously characterized a secretedP. aeruginosapeptidase, PaAP, that is highly expressed in chronic CF isolates. This leucine aminopeptidase is not only secreted solubly, it also associates with bacterial outer membrane vesicles (OMVs), structures known for their contribution to virulence mechanisms in a variety of Gram-negative species and one of the major components of the biofilm matrix. With this in mind, we hypothesized that PaAP may play a role inP. aeruginosabiofilm formation. Using a lung epithelial cell/bacterial biofilm coculture model, we show that PaAP deletion in a clinicalP. aeruginosabackground leads to increased early biofilm formation. We additionally found that only native vesicle-bound PaAP, as opposed to its soluble forms, could reconstitute the original PaAP-mediated inhibition phenotype, and that the PaAP-containing vesicles could disperse preformed biofilm microcolonies ofKlebsiella pneumoniae, another lung pathogen. These data provide the basis for future work into the mechanism behind PaAP-OMV mediated bacterial microcolony dispersal and the application of these findings to clinical anti-biofilm research.


Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1198
Author(s):  
Emanuela Boštjančič ◽  
Željka Večerić-Haler ◽  
Nika Kojc

MicroRNAs (miRNAs) are members of the non-coding regulatory RNA family that play pivotal roles in physiological and pathological conditions, including immune response. They are particularly interesting as promising therapeutic targets, prognostic and diagnostic markers due to their easy detection in body fluids and stability. There is accumulating evidence that different miRNAs provide disease-specific signatures in liquid samples of distinct kidney injuries. Using experimental models and human samples, there have been numerous suggestions that immune-related miRNAs are also important contributors to the development of different kidney diseases as well as important markers for monitoring response after kidney transplantation. However, there are limited data for understanding their function in the molecular pathways of allograft pathologies. In our review, we focused on microRNAs that are related to different aspects of immune response after kidney transplantation.


Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1074
Author(s):  
Natalia Vacani-Martins ◽  
Marcelo Meuser-Batista ◽  
Carina de Lima Pereira dos Santos ◽  
Alejandro Marcel Hasslocher-Moreno ◽  
Andrea Henriques-Pons

Chagas disease was described more than a century ago and, despite great efforts to understand the underlying mechanisms that lead to cardiac and digestive manifestations in chronic patients, much remains to be clarified. The disease is found beyond Latin America, including Japan, the USA, France, Spain, and Australia, and is caused by the protozoan Trypanosoma cruzi. Dr. Carlos Chagas described Chagas disease in 1909 in Brazil, and hepatomegaly was among the clinical signs observed. Currently, hepatomegaly is cited in most papers published which either study acutely infected patients or experimental models, and we know that the parasite can infect multiple cell types in the liver, especially Kupffer cells and dendritic cells. Moreover, liver damage is more pronounced in cases of oral infection, which is mainly found in the Amazon region. However, the importance of liver involvement, including the hepatic immune response, in disease progression does not receive much attention. In this review, we present the very first paper published approaching the liver’s participation in the infection, as well as subsequent papers published in the last century, up to and including our recently published results. We propose that, after infection, activated peripheral T lymphocytes reach the liver and induce a shift to a pro-inflammatory ambient environment. Thus, there is an immunological integration and cooperation between peripheral and hepatic immunity, contributing to disease control.


2013 ◽  
Vol 2 (4) ◽  
pp. 487-492 ◽  
Author(s):  
Noriaki Kawanishi ◽  
Hiromi Yano ◽  
Tsubasa Mizokami ◽  
Katsuhiko Suzuki

2020 ◽  
Vol 11 ◽  
Author(s):  
Verónica L. Burstein ◽  
Ignacio Beccacece ◽  
Lorena Guasconi ◽  
Cristian J. Mena ◽  
Laura Cervi ◽  
...  

Dermatophytoses (ringworms) are among the most frequent skin infections and are a highly prevalent cause of human disease worldwide. Despite the incidence of these superficial mycoses in healthy people and the compelling evidence on chronic and deep infections in immunocompromised individuals, the mechanisms controlling dermatophyte invasion in the skin are scarcely known. In the last years, the association between certain primary immunodeficiencies and the susceptibility to severe dermatophytosis as well as the evidence provided by novel experimental models mimicking human disease have significantly contributed to deciphering the basic immunological mechanisms against dermatophytes. In this review, we outline the current knowledge on fungal virulence factors involved in the pathogenesis of dermatophytoses and recent evidence from human infections and experimental models that shed light on the cells and molecules involved in the antifungal cutaneous immune response. The latest highlights emphasize the contribution of C-type lectin receptors signaling and the cellular immune response mediated by IL-17 and IFN-γ in the anti-dermatophytic defense and skin inflammation control.


2019 ◽  
Vol 18 (2) ◽  
pp. 171-175 ◽  
Author(s):  
Pooja Gupta ◽  
Hari Shankar Singh ◽  
Vijay K. Shukla ◽  
Gopal Nath ◽  
Satyanam Kumar Bhartiya

Background: A chronic wound usually results due to halt in the inflammatory phase of wound healing. Bacterial infections and biofilm formation are considered to be the basic cause of it. Chronic wounds significantly impair the quality of life. Antibiotics are now failing due to biofilm formation emergence of drug-resistant bacteria. Objective: This study aims to see the effect of bacteriophage therapy in chronic nonhealing wound infected with the following bacteria: Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Subject: Patients with chronic nonhealing wound not responding to conventional local debridement and antibiotic therapy were included in the study. The age of patients ranged between 12 and 60 years. Method: A total of 20 patients selected and tissue biopsies and wound swabs were taken for isolation of the bacteria. After confirmation of organism, a cocktail of customized bacteriophages was topically applied over the wound on alternate days till the wound surface became microbiologically sterile. Mean bacterial count and clinical assessment were done and compared at the time of presentation and after 3 and 5 doses of application. Results: A significant improvement was observed in the wound healing, and there were no signs of infection clinically and microbiologically after 3 to 5 doses of topical bacteriophage therapy. Seven patients achieved complete healing on day21 during follow up while in others healthy margins and healthy granulation tissue were observed. Conclusion: Topical bacteriophage application may be quite effective therapy for the treatment of chronic nonhealing wounds.


2020 ◽  
Vol 8 (11) ◽  
pp. 1823
Author(s):  
Joanna Kwiecińska-Piróg ◽  
Jana Przekwas ◽  
Michał Majkut ◽  
Krzysztof Skowron ◽  
Eugenia Gospodarek-Komkowska

Chronic wound infections are difficult to manage because of the biofilm formation in the wound environment. New measures for eliminating infections are necessary to increase the chance of wound healing. Apitherapy may be the new solution. The aim of this study was to assess the prevalence of wound infection factors and to examine the impact of Manuka honey and ethanol extract of propolis on biofilm formation of Proteus mirabilis isolated from chronic wound infections. According to the findings, the most frequent factors of infection are Staphylococcus aureus (46.1%), Pseudomonas aeruginosa (35.0%), and Proteus mirabilis (10.6%). Minimal inhibitory concentration and minimal bactericidal concentration values were assigned using the microbroth dilution test according to the Clinical and Laboratory Standards Institute. Biofilm of Proteus mirabilis isolates was formed in 96-well polystyrene plates and treated with Manuka honey (concentrations from 1.88% to 30.0%) and ethanol extract of propolis (1.0% to 40.0%). After 24 h, the biofilm viability was expressed by formazan absorbance (λ = 470 nm). Manuka honey reduced the biofilm viability in all, and ethanol extract of propolis in most, of the concentrations tested. Ethanol extract of propolis at the concentrations of 20.0% and 40.0%, reduced biofilm viability stronger than ethanol itself. With these results comes the conclusion that these substances can reduce biofilm formation.


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