scholarly journals Phage Therapy as a Focused Management Strategy in Aquaculture

2021 ◽  
Vol 22 (19) ◽  
pp. 10436
Author(s):  
José Ramos-Vivas ◽  
Joshua Superio ◽  
Jorge Galindo-Villegas ◽  
Félix Acosta

Therapeutic bacteriophages, commonly called as phages, are a promising potential alternative to antibiotics in the management of bacterial infections of a wide range of organisms including cultured fish. Their natural immunogenicity often induces the modulation of a variated collection of immune responses within several types of immunocytes while promoting specific mechanisms of bacterial clearance. However, to achieve standardized treatments at the practical level and avoid possible side effects in cultivated fish, several improvements in the understanding of their biology and the associated genomes are required. Interestingly, a particular feature with therapeutic potential among all phages is the production of lytic enzymes. The use of such enzymes against human and livestock pathogens has already provided in vitro and in vivo promissory results. So far, the best-understood phages utilized to fight against either Gram-negative or Gram-positive bacterial species in fish culture are mainly restricted to the Myoviridae and Podoviridae, and the Siphoviridae, respectively. However, the current functional use of phages against bacterial pathogens of cultured fish is still in its infancy. Based on the available data, in this review, we summarize the current knowledge about phage, identify gaps, and provide insights into the possible bacterial control strategies they might represent for managing aquaculture-related bacterial diseases.

2021 ◽  
Author(s):  
Moataz Dowaidar

A feasible alternative to state-of-the-art enzymatic nucleases was created by regulating the cleavage activity of metal complexes using (covalent or non-covalent) homing agents. Targeted AMNs, unlike enzymatic nucleases, break DNA by an oxidative mechanism and can therefore permanently knock off genes. Compared to larger enzymatic nucleases, the modest size of the metal complex may aid cellular transfection. Furthermore, the painstaking construction of the sequence-specific probe permits a metal complex to be directed to dsDNA's minor or major groove. To direct the chemical reactivity of several small-molecule compounds to dsDNA's minor groove, covalently bonded polyamide samples were used. PNA and DNA were also used to construct antisense and antigen hybrids, with Watson–Crick or Hoogsteen base pairing with major groove nucleobases giving sequence recognition. Click chemistry created chimeric AMN-TFOs with desirable focused effects and negligible off-target cleavage. Clip-Phen-modified TFOs, 230 polypyridyl-modified TFOs, 232 and intercalating phenanthrene-modified TFOs are three contemporary instances of copper AMN–TFOs. All three systems have distinct advantages in maintaining the desired 2:1 phenthroline/copper ratio for DNA cleavage (clip-Phen TFOs), caging the copper center and facilitating efficient ROS-mediated strand scission (polypyridyl-modified TFO) and improving triplex stability (polypyridyl-modified TFO) (phenanthrene-TFOs). Cerium (IV)/EDTA complexes, recently shown to bind and hydrolytically cleave ssDNA/dsDNA junctions and used in conjunction with PNA to successfully introduce genome changes in vitro and in vivo, are another important class of targeted chemical nucleases. The chemical reactivity and wide flexibility of metal complex design, combined with their coupling to sequence specific samples for directed applications, show that these compounds have a wide range of untapped applications in biological fields such as chemotherapy, protein engineering, DNA footprinting, and gene editing. Parallel advancements in cell and tissue targeting will be essential to maximise their therapeutic potential, either by using specific ligands or creating new targeting modalities.


Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1039
Author(s):  
Hana S. Fukuto ◽  
Gloria I. Viboud ◽  
Viveka Vadyvaloo

Yersinia pestis, the causative agent of plague, has a complex infectious cycle that alternates between mammalian hosts (rodents and humans) and insect vectors (fleas). Consequently, it must adapt to a wide range of host environments to achieve successful propagation. Y. pestis PhoP is a response regulator of the PhoP/PhoQ two-component signal transduction system that plays a critical role in the pathogen’s adaptation to hostile conditions. PhoP is activated in response to various host-associated stress signals detected by the sensor kinase PhoQ and mediates changes in global gene expression profiles that lead to cellular responses. Y. pestis PhoP is required for resistance to antimicrobial peptides, as well as growth under low Mg2+ and other stress conditions, and controls a number of metabolic pathways, including an alternate carbon catabolism. Loss of phoP function in Y. pestis causes severe defects in survival inside mammalian macrophages and neutrophils in vitro, and a mild attenuation in murine plague models in vivo, suggesting its role in pathogenesis. A Y. pestisphoP mutant also exhibits reduced ability to form biofilm and to block fleas in vivo, indicating that the gene is also important for establishing a transmissible infection in this vector. Additionally, phoP promotes the survival of Y. pestis inside the soil-dwelling amoeba Acanthamoeba castellanii, a potential reservoir while the pathogen is quiescent. In this review, we summarize our current knowledge on the mechanisms of PhoP-mediated gene regulation in Y. pestis and examine the significance of the roles played by the PhoP regulon at each stage of the Y. pestis life cycle.


2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Katia Rupel ◽  
Luisa Zupin ◽  
Giulia Ottaviani ◽  
Iris Bertani ◽  
Valentina Martinelli ◽  
...  

Abstract Resolution of bacterial infections is often hampered by both resistance to conventional antibiotic therapy and hiding of bacterial cells inside biofilms, warranting the development of innovative therapeutic strategies. Here, we report the efficacy of blue laser light in eradicating Pseudomonas aeruginosa cells, grown in planktonic state, agar plates and mature biofilms, both in vitro and in vivo, with minimal toxicity to mammalian cells and tissues. Results obtained using knock-out mutants point to oxidative stress as a relevant mechanism by which blue laser light exerts its anti-microbial effect. Finally, the therapeutic potential is confirmed in a mouse model of skin wound infection. Collectively, these data set blue laser phototherapy as an innovative approach to inhibit bacterial growth and biofilm formation, and thus as a realistic treatment option for superinfected wounds.


2019 ◽  
Vol 116 (20) ◽  
pp. 10072-10080 ◽  
Author(s):  
Bradley E. Poulsen ◽  
Rui Yang ◽  
Anne E. Clatworthy ◽  
Tiantian White ◽  
Sarah J. Osmulski ◽  
...  

Genomics offered the promise of transforming antibiotic discovery by revealing many new essential genes as good targets, but the results fell short of the promise. While numerous factors contributed to the disappointing yield, one factor was that essential genes for a bacterial species were often defined based on a single or limited number of strains grown under a single or limited number of in vitro laboratory conditions. In fact, the essentiality of a gene can depend on both the genetic background and growth condition. We thus developed a strategy for more rigorously defining the core essential genome of a bacterial species by studying many pathogen strains and growth conditions. We assessed how many strains must be examined to converge on a set of core essential genes for a species. We used transposon insertion sequencing (Tn-Seq) to define essential genes in nine strains ofPseudomonas aeruginosaon five different media and developed a statistical model,FiTnEss, to classify genes as essential versus nonessential across all strain–medium combinations. We defined a set of 321 core essential genes, representing 6.6% of the genome. We determined that analysis of four strains was typically sufficient inP. aeruginosato converge on a set of core essential genes likely to be essential across the species across a wide range of conditions relevant to in vivo infection, and thus to represent attractive targets for novel drug discovery.


PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Tamotsu Tsukahara

In recent years, peroxisome proliferator-activated receptor gamma (PPARγ) has been reported to be a target for the treatment of type II diabetes. Furthermore, it has received attention for its therapeutic potential in many other human diseases, including atherosclerosis, obesity, and cancers. Recent studies have provided evidence that the endogenously produced PPARγ antagonist, 2,3-cyclic phosphatidic acid (cPA), which is similar in structure to lysophosphatidic acid (LPA), inhibits cancer cell invasion and metastasisin vitroandin vivo. We recently observed that cPA negatively regulates PPARγ function by stabilizing the binding of the corepressor protein, silencing mediator of retinoic acid and thyroid hormone receptor. We also showed that cPA prevents neointima formation, adipocyte differentiation, lipid accumulation, and upregulation of PPARγ target gene transcription. We then analyzed the molecular mechanism of cPA's action on PPARγ. In this paper, we summarize the current knowledge on the mechanism of PPARγ-mediated transcriptional activity and transcriptional repression in response to novel lipid-derived ligands, such as cPA.


2005 ◽  
Vol 49 (10) ◽  
pp. 4185-4196 ◽  
Author(s):  
Yutaka Ueda ◽  
Katsunori Kanazawa ◽  
Ken Eguchi ◽  
Koji Takemoto ◽  
Yoshiro Eriguchi ◽  
...  

ABSTRACT SM-216601 is a novel parenteral 1β-methylcarbapenem. In agar dilution susceptibility testing, the MIC of SM-216601 for 90% of the methicillin-resistant Staphylococcus aureus (MRSA) strains tested (MIC90) was 2 μg/ml, which was comparable to those of vancomycin and linezolid. SM-216601 was also very potent against Enterococcus faecium, including vancomycin-resistant strains (MIC90 = 8 μg/ml). SM-216601 exhibited potent activity against penicillin-resistant Streptococcus pneumoniae, ampicillin-resistant Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, with MIC90s of less than 0.5 μg/ml, and intermediate activity against Citrobacter freundii, Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa. The therapeutic efficacy of SM-216601 against experimentally induced infections in mice caused by S. aureus, E. faecium, E. coli, and P. aeruginosa reflected its in vitro activity and plasma level. Thus, SM-216601 is a promising candidate for nosocomial bacterial infections caused by a wide range of gram-positive and gram-negative bacteria, including multiresistant pathogens.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e15594-e15594
Author(s):  
Scott Strum ◽  
Laszlo Gyenis ◽  
David W Litchfield

e15594 Background: Protein kinase CSNK2 (CK2) is a pleiotropic serine/threonine kinase whose expression levels are frequently elevated in solid and hematologic malignancies. CSNK2 has been discovered to hold prognostic and therapeutic significance across multiple cancers and is an excellent target for oncology research. This systematic review summarizes the current knowledge from in vitro and in vivo studies on the biology of this kinase in cancer alongside pre-clinical/clinical investigations from 24 different human cancer types. Methods: PRISMA methodology was used to generate a study protocol and building-block search strategy, from which a total of 796 publications in PubMed were retrieved across 24 human cancers. 245 of these publications met both screening and inclusion criteria. Data was then systematically extracted, including information about CSNK2 subunit mRNA/protein/activity levels, phosphorylation targets, phenotypic changes, in vivo studies, and prognostic/therapeutic data. The data was thereafter summarized and analyzed. Results: Five targets phosphorylated by CSNK2 were identified in at least 4 cancers: AKT, STAT3, RELA, PTEN, and TP53. The most heavily cited was AKT, identified in 15 cancers. Phenotypically, behaviors influenced by CSNK2 that were reported in 11 or more cancers included: evasion of apoptosis, enhancement of proliferation, enhancement of invasion/metastasis, and cell cycle control. Interestingly, these pathways correlated heavily with the most commonly cited CSNK2 targets. From a clinical perspective, CSNK2 held prognostic significance in 17 of the cancers. Additionally, xenograft experiments were found to have been performed in 13 cancers where CSNK2 inhibition resulted in a positive response to treatment. Lastly, early studies have shown promising results through the clinical application of CSNK2-specific inhibitors, with several clinical trials now underway for further assessment. Conclusions: Overall, our analysis supports CSNK2 as an attractive target for cancer therapy and points to specific areas where additional investigation is critical to advance our understanding of CSNK2 biology. The design of targeted therapies by exploiting the pathophysiology of CSNK2 has the potential to generate impactful treatment strategies across a wide range of cancers, promising exciting new discoveries scientifically and clinically.


2007 ◽  
Vol 114 (2) ◽  
pp. 99-108 ◽  
Author(s):  
Michael R. Loebinger ◽  
Susana Aguilar ◽  
Sam M. Janes

There has been increasing excitement over the last few years with the suggestion that exogenous stem cells may offer new treatment options for a wide range of diseases. Within respiratory medicine, these cells have been shown to have the ability to differentiate and function as both airway and lung parenchyma epithelial cells in both in vitro and increasingly in vivo experiments. The hypothesis is that these cells may actively seek out damaged tissue to assist in the local repair, and the hope is that their use will open up new cellular and genetic treatment modalities. Such is the promise of these cells that they are being rushed from the benchside to the bedside with the commencement of early clinical trials. However, important questions over their use remain and the field is presently littered with controversy and uncertainty. This review evaluates the progress made and the pitfalls encountered to date, and critically assesses the evidence for the use of stem cells in lung disease.


2021 ◽  
Vol 22 (15) ◽  
pp. 8312
Author(s):  
Daniela Valenti ◽  
Rosa Anna Vacca ◽  
Loredana Moro ◽  
Anna Atlante

Mitochondria are complex intracellular organelles traditionally identified as the powerhouses of eukaryotic cells due to their central role in bioenergetic metabolism. In recent decades, the growing interest in mitochondria research has revealed that these multifunctional organelles are more than just the cell powerhouses, playing many other key roles as signaling platforms that regulate cell metabolism, proliferation, death and immunological response. As key regulators, mitochondria, when dysfunctional, are involved in the pathogenesis of a wide range of metabolic, neurodegenerative, immune and neoplastic disorders. Far more recently, mitochondria attracted renewed attention from the scientific community for their ability of intercellular translocation that can involve whole mitochondria, mitochondrial genome or other mitochondrial components. The intercellular transport of mitochondria, defined as horizontal mitochondrial transfer, can occur in mammalian cells both in vitro and in vivo, and in physiological and pathological conditions. Mitochondrial transfer can provide an exogenous mitochondrial source, replenishing dysfunctional mitochondria, thereby improving mitochondrial faults or, as in in the case of tumor cells, changing their functional skills and response to chemotherapy. In this review, we will provide an overview of the state of the art of the up-to-date knowledge on intercellular trafficking of mitochondria by discussing its biological relevance, mode and mechanisms underlying the process and its involvement in different pathophysiological contexts, highlighting its therapeutic potential for diseases with mitochondrial dysfunction primarily involved in their pathogenesis.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1454
Author(s):  
Young-Kyung Jung ◽  
Dongyun Shin

Imperata cylindrica is a medicinal plant native to southwestern Asia and the tropical and subtropical zones. To date, 72 chemical constituents have been isolated and identified from I. cylindrica Among these compounds, saponins, flavonoids, phenols, and glycosides are the major constituents. Investigations of pharmacological activities of I. cylindrica revealed that this edible medicinal herb exhibits a wide range of therapeutic potential including immunomodulatory, antibacterial, antitumor, anti-inflammatory, and liver protection activities both in vivo and in vitro. The purpose of this review is to provide an overview of I. cylindrica studies until 2019. This article also intends to review advances in the botanical, phytochemical, and pharmacological studies and industrial applications of I. cylindrica, which will provide a useful bibliography for further investigations and applications of I. cylindrica in medicines and foods.


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