scholarly journals Developing Tadpole Xenopus laevis as a Comparative Animal Model to Study Mycobacterium abscessus Pathogenicity

2021 ◽  
Vol 22 (2) ◽  
pp. 806
Author(s):  
Arianna Lopez ◽  
Carolyn Shoen ◽  
Michael Cynamon ◽  
Dionysia Dimitrakopoulou ◽  
Matthieu Paiola ◽  
...  
Keyword(s):  
Animal Model ◽  
Xenopus Laevis ◽  
Pulmonary Infection ◽  
Bacterial Load ◽  
Mycobacterium Abscessus ◽  
Zebrafish Model ◽  
Experimental Organism ◽  
Immunocompetent Mice ◽  
Significant Mortality

Mycobacterium abscessus (Mab) is an emerging, nontuberculosis mycobacterium (NTM) that infects humans. Mab has two morphotypes, smooth (S) and rough (R), related to the production of glycopeptidolipid (GPL), that differ in pathogenesis. To further understand the pathogenicity of these morphotypes in vivo, the amphibian Xenopus laevis was used as an alternative animal model. Mab infections have been previously modeled in zebrafish embryos and mice, but Mab are cleared early from immunocompetent mice, preventing the study of chronic infection, and the zebrafish model cannot be used to model a pulmonary infection and T cell involvement. Here, we show that X. laevis tadpoles, which have lungs and T cells, can be used as a complementary model for persistent Mab infection and pathogenesis. Intraperitoneal (IP) inoculation of S and R Mab morphotypes disseminated to tadpole tissues including liver and lungs, persisting for up to 40 days without significant mortality. Furthermore, the R morphotype was more persistent, maintaining a higher bacterial load at 40 days postinoculation. In contrast, the intracardiac (IC) inoculation with S Mab induced significantly greater mortality than inoculation with the R Mab form. These data suggest that X. laevis tadpoles can serve as a useful comparative experimental organism to investigate pathogenesis and host resistance to M. abscessus.

scholarly journals Rifabutin Is Bactericidal against Intracellular and Extracellular Forms of Mycobacterium abscessus

2020 ◽  
Vol 64 (11) ◽  
Author(s):  
Matt D. Johansen ◽  
Wassim Daher ◽  
Françoise Roquet-Banères ◽  
Clément Raynaud ◽  
Matthéo Alcaraz ◽  
...  
Keyword(s):  
Opportunistic Pathogen ◽  
Mycobacterium Abscessus ◽  
Zebrafish Model ◽  
Content Type ◽  
Attractive Option ◽  
Conventional Antibiotics ◽  
Susceptibility Profiles ◽  
Combination Regimens

ABSTRACT Mycobacterium abscessus is increasingly recognized as an emerging opportunistic pathogen causing severe lung diseases. As it is intrinsically resistant to most conventional antibiotics, there is an unmet medical need for effective treatments. Repurposing of clinically validated pharmaceuticals represents an attractive option for the development of chemotherapeutic alternatives against M. abscessus infections. In this context, rifabutin (RFB) has been shown to be active against M. abscessus and has raised renewed interest in using rifamycins for the treatment of M. abscessus pulmonary diseases. Here, we compared the in vitro and in vivo activity of RFB against the smooth and rough variants of M. abscessus, differing in their susceptibility profiles to several drugs and physiopathologial characteristics. While the activity of RFB is greater against rough strains than in smooth strains in vitro, suggesting a role of the glycopeptidolipid layer in susceptibility to RFB, both variants were equally susceptible to RFB inside human macrophages. RFB treatment also led to a reduction in the number and size of intracellular and extracellular mycobacterial cords. Furthermore, RFB was highly effective in a zebrafish model of infection and protected the infected larvae from M. abscessus-induced killing. This was corroborated by a significant reduction in the overall bacterial burden, as well as decreased numbers of abscesses and cords, two major pathophysiological traits in infected zebrafish. This study indicates that RFB is active against M. abscessus both in vitro and in vivo, further supporting its potential usefulness as part of combination regimens targeting this difficult-to-treat mycobacterium.

scholarly journals Anti-quorum Sensing and Protective Efficacies of Naringin Against Aeromonas hydrophila Infection in Danio rerio

2020 ◽  
Vol 11 ◽  
Author(s):  
Ramanathan Srinivasan ◽  
Kannan Rama Devi ◽  
Sivasubramanian Santhakumari ◽  
Arunachalam Kannappan ◽  
Xiaomeng Chen ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Quorum Sensing ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Bacterial Load ◽  
Antibiotic Resistance Genes ◽  
Alternative Methods ◽  
Zebrafish Model ◽  
Virulence Gene Expression

It is now well known that the quorum sensing (QS) mechanism coordinates the production of several virulence factors and biofilm formation in most pathogenic microorganisms. Aeromonas hydrophila is a prime pathogen responsible for frequent outbreaks in aquaculture settings. Recent studies have also continuously reported that A. hydrophila regulates virulence factor production and biofilm formation through the QS system. In addition to the presence of antibiotic resistance genes, biofilm-mediated antibiotic resistance increases the severity of A. hydrophila infections. To control the bacterial pathogenesis and subsequent infections, targeting the QS mechanism has become one of the best alternative methods. Though very few compounds were identified as QS inhibitors against A. hydrophila, to date, the screening and identification of new and effective natural QS inhibitors is a dire necessity to control the infectious A. hydrophila. The present study endorses naringin (NA) as an anti-QS and anti-infective agent against A. hydrophila. Initially, the NA showed a concentration-dependent biofilm reduction against A. hydrophila. Furthermore, the results of microscopic analyses and quantitative virulence assays displayed the promise of NA as a potential anti-QS agent. Subsequently, the downregulation of ahh1, aerA, lip and ahyB validate the interference of NA in virulence gene expression. Furthermore, the in vivo assays were carried out in zebrafish model system to evaluate the anti-infective potential of NA. The outcome of the immersion challenge assay showed that the recovery rate of the zebrafish has substantially increased upon treatment with NA. Furthermore, the quantification of the bacterial load upon NA treatment showed a decreased level of bacterial counts in zebrafish when compared to the untreated control. Moreover, the NA treatment averts the pathogen-induced histoarchitecture damages in vital organs of zebrafish, compared to their respective controls. The current study has thus analyzed the anti-QS and anti-infective capabilities of NA and could be employed to formulate effective treatment measures against A. hydrophila infections.

scholarly journals AR-12 Exhibits Direct and Host-Targeted Antibacterial Activity toward Mycobacterium abscessus

2020 ◽  
Vol 64 (8) ◽  
Author(s):  
Shaoyan Zhang ◽  
Yuzhen Zou ◽  
Qi Guo ◽  
Jianhui Chen ◽  
Liyun Xu ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Minimum Bactericidal Concentration ◽  
Bacterial Load ◽  
Mycobacterium Abscessus ◽  
Potential Candidate ◽  
Content Type ◽  
Repurposed Drugs ◽  
Time Kill

ABSTRACT Therapeutic options for Mycobacterium abscessus infections are extremely limited. New or repurposed drugs are needed. The anti-M. abscessus activity of AR-12 (OSU-03012), reported to express broad-spectrum antimicrobial effects, was investigated in vitro and in vivo. Antimicrobial susceptibility testing was performed on 194 clinical isolates. Minimum bactericidal concentration and time-kill kinetics assays were conducted to distinguish the bactericidal versus bacteriostatic activity of AR-12. Synergy between AR-12 and five clinically important antibiotics was determined using a checkerboard synergy assay. The activity of AR-12 against intracellular M. abscessus residing within macrophage was also evaluated. Finally, the potency of AR-12 in vivo was determined in a neutropenic mouse model that mimics pulmonary M. abscessus infection. AR-12 exhibited high anti-M. abscessus activity in vitro, with an MIC50 of 4 mg/liter (8.7 μM) and an MIC90 of 8 mg/liter (17.4 μM) for both subsp. abscessus and subsp. massiliense. AR-12 and amikacin exhibited comparable bactericidal activity against extracellular M. abscessus in culture. AR-12, however, exhibited significantly greater intracellular antibacterial activity than amikacin and caused a significant reduction in the bacterial load in the lungs of neutropenic mice infected with M. abscessus. No antagonism between AR-12 and clarithromycin, amikacin, imipenem, cefoxitin, or tigecycline was evident. In conclusion, AR-12 is active against M. abscessus in vitro and in vivo and does not antagonize the most frequently used anti-M. abscessus drugs. As such, AR-12 is a potential candidate to include in novel strategies to treat M. abscessus infections.

scholarly journals Zebrafish-Based Screening Models for the Identification of Anti-Metastatic Drugs

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2407
Author(s):  
Joji Nakayama ◽  
Hideki Makinoshima
Keyword(s):  
Animal Model ◽  
Drug Discovery ◽  
Cancer Cells ◽  
High Throughput Screening ◽  
Metastatic Tumor ◽  
Tumor Formation ◽  
Zebrafish Model ◽  
Step Process ◽  
Physiological Relevance

Metastasis, a leading contributor to the morbidity of cancer patients, occurs through a multi-step process: invasion, intravasation, extravasation, colonization, and metastatic tumor formation. Each process is not only promoted by cancer cells themselves but is also affected by their microenvironment. Given this complexity, drug discovery for anti-metastatic drugs must consider the interaction between cancer cells and their microenvironments. The zebrafish is a suitable vertebrate animal model for in vivo high-throughput screening studies with physiological relevance to humans. This review covers the zebrafish model used to identify anti-metastatic drugs.

scholarly journals Rufomycin Exhibits Dual Effects Against Mycobacterium abscessus Infection by Inducing Host Defense and Antimicrobial Activities

2021 ◽  
Vol 12 ◽  
Author(s):  
Cho Rong Park ◽  
Seungwha Paik ◽  
Young Jae Kim ◽  
Jin Kyung Kim ◽  
Sang Min Jeon ◽  
...  
Keyword(s):  
Pulmonary Infection ◽  
Nuclear Translocation ◽  
Antimicrobial Activities ◽  
Mycobacterium Abscessus ◽  
Immune Defense ◽  
New Drugs ◽  
Innate Defense ◽  
Host Immune Responses ◽  
Oxidative Stresses

Nontuberculous mycobacterial pulmonary infection is often aggravated due to antibiotic resistance issues. There is a need for development of new drugs inducing both host immune responses and antimicrobial activities. This study shows that the rufomycins 4/5/6/7 (Rufomycin 4–7), which targets ClpC1 as a subunit of caseinolytic protein complex ClpC1/ClpP1/ClpP2 of mycobacteria, exhibits a dual effect in host innate defense and in vivo antimicrobial activities against a rough morphotype of Mycobacterium abscessus (Mabs-R), a clinically severe morphotype that causes hyperinflammation. Rufomycin 4–7 treatment showed antimicrobial effects against Mabs pulmonary infection in vivo and in macrophages. In addition, Rufomycin 4–7 significantly decreased inflammation, but enhanced the autophagy/lysosomal genes through upregulation of the nuclear translocation of transcription factor EB (TFEB). Furthermore, Rufomycin 4–7 treatment effectively inhibited mitochondrial damage and oxidative stresses in macrophages during Mabs-R infection. Collectively, Rufomycin 4–7-mediated dual effects inducing both antimicrobial activities and host immune defense might confer an advantage to treatment against Mabs-R infection.

scholarly journals Efficacy of the New Lantibiotic NAI-107 in Experimental Infections Induced by Multidrug-Resistant Gram-Positive Pathogens

2011 ◽  
Vol 55 (4) ◽  
pp. 1671-1676 ◽  
Author(s):  
Daniela Jabés ◽  
Cristina Brunati ◽  
GianPaolo Candiani ◽  
Simona Riva ◽  
Gabriella Romanó ◽  
...  
Keyword(s):  
Bactericidal Activity ◽  
Bacterial Load ◽  
Severe Infection ◽  
Multidrug Resistant ◽  
Minimal Bactericidal Concentration ◽  
Gram Positive ◽  
Immunocompetent Mice ◽  
Dose Proportional

ABSTRACTNAI-107 is a novel lantibiotic active against Gram-positive bacteria, including methicillin-resistantStaphylococcus aureus(MRSA), glycopeptide-intermediateS. aureus(GISA), and vancomycin-resistant enterococci (VRE). The aim of this study was to evaluate thein vivoefficacy of NAI-107 in animal models of severe infection. In acute lethal infections induced with a penicillin-intermediateStreptococcus pneumoniaestrain in immunocompetent mice, or with MRSA, GISA, and VRE strains in neutropenic mice, the 50% effective dose (ED50) values of NAI-107 were comparable or lower than those of reference compounds, irrespective of the strain and immune status (0.51 to 14.2 mg/kg of body weight for intravenous [i.v.] NAI-107, 5.1 to 22.4 for oral linezolid, and 22.4 for subcutaneous [s.c.] vancomycin). Inthe granuloma pouch model induced in rats with a MRSA strain, intravenous NAI-107 showed a dose-proportional bactericidal activity that, at a single 40-mg/kg dose, compared with 2 20-mg/kg doses at a 12-h or 24-h interval, caused a 3-log10-CFU/ml reduction of viable MRSA in exudates that persisted for more than 72 h. Rat endocarditis was induced with a MRSA strain and treated for five consecutive days. In a first experiment, using 5, 10, or 20 mg/kg/day, and in a second experiment, when 10 mg/kg at 12-h intervals was compared to 20 mg/kg/day, intravenous NAI-107 was effective in reducing the bacterial load in heart vegetations in a dose-proportional manner. Trough plasma levels, as determined on days 2 and 5, were several times higher than the NAI-107 minimal bactericidal concentration (MBC). NAI-107 binding to rat and human serum ranges between 93% and 98.6%. The rapid bactericidal activity of NAI-107 observedin vitrowas thus confirmed by the efficacy in several models of experimental infection induced by Gram-positive pathogens, supporting further investigation of the compound.

scholarly journals Bedaquiline Inhibits the ATP Synthase in Mycobacterium abscessus and Is Effective in Infected Zebrafish

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Christian Dupont ◽  
Albertus Viljoen ◽  
Sangeeta Thomas ◽  
Françoise Roquet-Banères ◽  
Jean-Louis Herrmann ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Multidrug Resistant ◽  
Mycobacterium Abscessus ◽  
Nucleotide Polymorphisms ◽  
Pulmonary Infections ◽  
Zebrafish Model ◽  
Content Type ◽  
Short Period

ABSTRACT Pulmonary infections caused by Mycobacterium abscessus are emerging as a global threat, especially in cystic fibrosis patients. Further intensifying the concern of M. abscessus infection is the recent evidence of human-to-human transmission of the infection. M. abscessus is a naturally multidrug-resistant fast-growing pathogen for which pharmacological options are limited. Repurposing antitubercular drugs represents an attractive option for the development of chemotherapeutic alternatives against M. abscessus infections. Bedaquiline (BDQ), an ATP synthase inhibitor, has recently been approved for the treatment of multidrug-resistant tuberculosis. Herein, we show that BDQ has a very low MIC against a vast panel of clinical isolates. Despite being bacteriostatic in vitro, BDQ was highly efficacious in a zebrafish model of M. abscessus infection. Remarkably, a very short period of treatment was sufficient to protect the infected larvae from M. abscessus-induced killing. This was corroborated with reduced numbers of abscesses and cords, considered to be major pathophysiological signs in infected zebrafish. Mode-of-action studies revealed that BDQ triggered a rapid depletion of ATP in M. abscessus in vitro, consistent with the drug targeting the FoF1 ATP synthase. Importantly, despite a failure to select in vitro for spontaneous mutants that are highly resistant to BDQ, the transfer of single nucleotide polymorphisms leading to D29V or A64P substitutions in atpE conferred high resistance, thus resolving the target of BDQ in M. abscessus. Overall, this study indicates that BDQ is active against M. abscessus in vitro and in vivo and should be considered for clinical use against the difficult-to-manage M. abscessus pulmonary infections.

scholarly journals Efficacy of Aerosol MP-376, a Levofloxacin Inhalation Solution, in Models of Mouse Lung Infection Due to Pseudomonas aeruginosa

2009 ◽  
Vol 53 (9) ◽  
pp. 3923-3928 ◽  
Author(s):  
Mojgan Sabet ◽  
Courtney E. Miller ◽  
Thomas G. Nolan ◽  
Kathy Senekeo-Effenberger ◽  
Michael N. Dudley ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pulmonary Infection ◽  
Antimicrobial Agents ◽  
Bacterial Load ◽  
Lung Infection ◽  
In Vivo Studies ◽  
Mouse Lung ◽  
Bacterial Killing ◽  
High Concentrations

ABSTRACT Progressive respiratory failure due to Pseudomonas aeruginosa is the leading cause of morbidity and mortality in patients with cystic fibrosis. The pulmonary delivery of antimicrobial agents provides high concentrations of drug directly to the site of infection and attains pharmacokinetic-pharmacodynamic indices exceeding those which can be achieved with systemic dosing. MP-376 is a new formulation of levofloxacin that enables the safe aerosol delivery of high concentrations of drug to pulmonary tissues. In vivo studies were conducted to demonstrate the efficacy of MP-376 in models of mouse pulmonary infection. The superiority of aerosol dosing over systemic dosing was demonstrated in models of both acute and chronic lung infection. In a model of acute lung infection, aerosol treatment with MP-376 once or twice daily reduced the lung bacterial load to a greater extent than aerosol tobramycin or aztreonam did when they were administered at similar or higher doses. The bacterial killing by aerosol MP-376 observed in the lung in the model of acute pulmonary infection translated to improved survival (P < 0.05). In a model of chronic pulmonary infection, aerosol MP-376 had antimicrobial effects superior to those of aztreonam (P < 0.05) and effects similar to those of tobramycin (P > 0.05). In summary, these data show that aerosol MP-376 has in vivo activity when it is used to treat acute and chronic lung infections caused by P. aeruginosa.

scholarly journals Variation in wall shear stress in channel networks of zebrafish models

2017 ◽  
Vol 14 (127) ◽  
pp. 20160900 ◽  
Author(s):  
Woorak Choi ◽  
Hye Mi Kim ◽  
Sungho Park ◽  
Eunseop Yeom ◽  
Junsang Doh ◽  
...  
Keyword(s):  
Animal Model ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Blood Vessels ◽  
Equivalent Circuit Model ◽  
Zebrafish Model ◽  
Typical Application ◽  
Wall Shear

Physiological functions of vascular endothelial cells (ECs) vary depending on wall shear stress (WSS) magnitude, and the functional change affects the pathologies of various cardiovascular systems. Several in vitro and in vivo models have been used to investigate the functions of ECs under different WSS conditions. However, these models have technical limitations in precisely mimicking the physiological environments of ECs and monitoring temporal variations of ECs in detail. Although zebrafish ( Danio rerio ) has several strategies to overcome these technical limitations, zebrafish cannot be used as a perfect animal model because applying various WSS conditions on blood vessels of zebrafish is difficult. This study proposes a new zebrafish model in which various WSS can be applied to the caudal vein. The WSS magnitude is controlled by blocking some parts of blood-vessel networks. The accuracy and reproducibility of the proposed method are validated using an equivalent circuit model of blood vessels in zebrafish. The proposed method is applied to lipopolysaccharide (LPS)-stimulated zebrafish as a typical application. The proposed zebrafish model can be used as an in vivo animal model to investigate the relationship between WSS and EC physiology or WSS-induced cardiovascular diseases.

scholarly journals MITO-Luc/GFP zebrafish model to assess spatial and temporal evolution of cell proliferation in vivo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luisa de Latouliere ◽  
Isabella Manni ◽  
Laura Ferrari ◽  
Federica Pisati ◽  
Maria Grazia Totaro ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Animal Model ◽  
Temporal Evolution ◽  
Luciferase Activity ◽  
Luciferase Expression ◽  
Transgenic Zebrafish ◽  
X Rays ◽  
Adult Zebrafish ◽  
Zebrafish Model

AbstractWe developed a novel reporter transgenic zebrafish model called MITO-Luc/GFP zebrafish in which GFP and luciferase expression are under the control of the master regulator of proliferation NF-Y. In MITO-Luc/GFP zebrafish it is possible to visualize cell proliferation in vivo by fluorescence and bioluminescence. In this animal model, GFP and luciferase expression occur in early living embryos, becoming tissue specific in juvenile and adult zebrafish. By in vitro and ex vivo experiments we demonstrate that luciferase activity in adult animals occurs in intestine, kidney and gonads, where detectable proliferating cells are located. Further, by time lapse experiments in live embryos, we observed a wave of GFP positive cells following fin clip. In adult zebrafish, in addition to a bright bioluminescence signal on the regenerating tail, an early unexpected signal coming from the kidney occurs indicating not only a fin cell proliferation, but also a systemic response to tissue damage. Finally, we observed that luciferase activity was inhibited by anti-proliferative interventions, i.e. 5FU, cell cycle inhibitors and X-Rays. In conclusion, MITO-Luc/GFP zebrafish is a novel animal model that may be crucial to assess the spatial and temporal evolution of cell proliferation in vivo.

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