scholarly journals Linalool Nanoemulsion Preparation, Characterization and Antimicrobial Activity against Aeromonas hydrophila

2021 ◽  
Vol 22 (20) ◽  
pp. 11003
Author(s):  
Weiming Zhong ◽  
Puyu Tang ◽  
Ting Liu ◽  
Tianyu Zhao ◽  
Jiajing Guo ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Electron Microscope ◽  
Aeromonas Hydrophila ◽  
Ultrasonic Method ◽  
Economic Losses ◽  
Disruptive Effect ◽  
Spherical Droplet ◽  
Control And Prevention ◽  
Nano Emulsion ◽  
Aquatic Pathogens

Aeromonas hydrophila is one of the most important aquatic pathogens causing huge economic losses to aquaculture. Linalool, a vital ingredient of a variety of essential oils, was proved as a good antimicrobial agent in our previous studies. However, the low solubility and volatility of Linalool obstruct its application in the field of aquatic drugs. Thus, in this study, Linalool nano-emulsion (LN) was prepared to solve these obstructions. We investigated the physicochemical properties, antibacterial activity, and mode of action of LN against A. hydrophila. LN with different medium chain triglycerides (MCT) concentrations were prepared by ultrasonic method. The results showed that the emulsion droplet size of LN was the smallest when MCT was not added to the formulation. Nano-emulsions are usually less than 500 nm in diameter. In our study, LN in this formulation were spherical droplet with a diameter of 126.57 ± 0.85 nm and showed good stability. LN showed strong antibacterial activity, the MIC and MBC values were 0.3125% v/v and 0.625% v/v, respectively. The bacterial population decreased substantially at 1 × MIC of LN. LN exhibited disruptive effect on cell membranes by scanning electron microscope (SEM) and transmission electron microscope (TEM). The present study provided a formulation of Linalool nano-emulsion preparation. Moreover, the good antibacterial activity of LN showed in our study will promote the application of Linalool for the control and prevention of A. hydrophila in aquaculture.

scholarly journals IN VITRO ANTIBACTERIAL EFFICACY OF LEAVES EXTRACT OF Centela asiatica AGAINST Vibrio harveyi AND Aeromonas hydrophila

2019 ◽  
Vol 14 (2) ◽  
pp. 69
Author(s):  
Rukisah Rukisah ◽  
Diana Maulianawati ◽  
Jimmy Cahyadi
Keyword(s):  
Antibacterial Activity ◽  
Aeromonas Hydrophila ◽  
Vibrio Harveyi ◽  
Centella Asiatica ◽  
Inhibition Zone ◽  
Limiting Factors ◽  
Economic Losses ◽  
Potential Use ◽  
Test Result

Disease infection is one of the limiting factors that affect productivity in aquaculture and has caused economic losses. Luminescent vibrios and motile aeromonas septicemia (MAS) are diseases caused by Vibrio harveyi and Aeromonas hydrophila bacteria, respectively. Certain plants have antimicrobial compounds and can potentially be used to treat the diseases, such as Centella asiatica. In the present study, the crude leaves extracts of C. asiatica were examined for its antibacterial potential using methanol solvents against V. harveyi and A. hydrophila bacteria. Different concentrations of 50 mg/mL and 100 mg/mL were checked for its antibacterial activity. The crude extract was also tested for phytochemistry content and LC50 using Brine Shrimp Lethal Assay. The crude extracts of C. asiatica showed a remarkable antibacterial activity with inhibition zone of 10.57 mm against A. hydrophila and 21.14 mm against V. harveyi. The phytochemistry test result showed that C. asiatica leaves contain alkaloid, phenol, and tannin compounds. The acute lethal concentration (LC50) of C. asiatica after 24 hours exposure to the extract mixture was 254 mg/L. The results confirmed the potential use of C. asiatica extracts as a source of antibacterial compounds.

scholarly journals Ginger Essential Oils-Loaded Nanoemulsions: Potential Strategy to Manage Bacterial Leaf Blight Disease and Enhanced Rice Yield

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3902
Author(s):  
Abdullahi Adamu ◽  
Khairulmazmi Ahmad ◽  
Yasmeen Siddiqui ◽  
Intan Safinar Ismail ◽  
Norhayu Asib ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Electron Microscope ◽  
Essential Oils ◽  
Disease Severity ◽  
Rice Yield ◽  
Cell Structure ◽  
Leaf Blight ◽  
Bacterial Leaf Blight ◽  
Control Treatment ◽  
Promising Alternative

The bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most serious rice diseases, causing huge yield losses worldwide. Several technologies and approaches have been opted to reduce the damage; however, these have had limited success. Recently, scientists have been focusing their efforts on developing efficient and environmentally friendly nanobactericides for controlling bacterial diseases in rice fields. In the present study, a scanning electron microscope (SEM), transmission electron microscope (TEM), and a confocal laser scanning microscope (CLSM) were utilized to investigate the mode of actions of ginger EOs on the cell structure of Xoo. The ginger EOs caused the cells to grow abnormally, resulting in an irregular form with hollow layers, whereas the dimethylsulfoxide (DMSO) treatment showed a typical rod shape for the Xoo cell. Ginger EOs restricted the growth and production of biofilms by reducing the number of biofilms generated as indicated by CLSM. Due to the instability, poor solubility, and durability of ginger EOs, a nanoemulsions approach was used, and a glasshouse trial was performed to assess their efficacy on BLB disease control. The in vitro antibacterial activity of the developed nanobactericides was promising at different concentration (50–125 µL/mL) tested. The efficacy was concentration-dependent. There was significant antibacterial activity recorded at higher concentrations. A glasshouse trial revealed that developed nanobactericides managed to suppress BLB disease severity effectively. Treatment at a concentration of 125 μL/mL was the best based on the suppression of disease severity index, AUDPC value, disease reduction (DR), and protection index (PI). Furthermore, findings on plant growth, physiological features, and yield parameters were significantly enhanced compared to the positive control treatment. In conclusion, the results indicated that ginger essential oils loaded-nanoemulsions are a promising alternative to synthetic antibiotics in suppressing Xoo growth, regulating the BLB disease, and enhancing rice yield under a glasshouse trial.

The Preparation of Carbon Microspheres Loading Silver Antimicrobial Agent and the Study of its Properties

2012 ◽  
Vol 550-553 ◽  
pp. 1026-1029
Author(s):  
Jian Xi Ren ◽  
Jing Ya Li ◽  
Zhi Feng Cai ◽  
Jin Ming Dai ◽  
Mei Niu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Electron Microscope ◽  
Antibacterial Agent ◽  
Chemical Adsorption ◽  
Carbon Microspheres ◽  
Bacterial Inhibition ◽  
Good Antibacterial Activity ◽  
Scanning Electron

Carbon microspheres (CMSs) were used as the carrier to prepare the Ag-loading CMSs (Ag/CMSs) antibacterial agent through the method of chemical adsorption. The morphologies and structures of modified CMSs were characterized by using the field emission Scanning Electron Microscope (SEM). The results showed that silver was absorbed on the surface of CMSs. The bacterial inhibition ring experiment showed that Ag/CMSs had good antibacterial activity against Staphylococcus aureus and Escherichia coli, meanwhile the diameters of the bacterial inhibition rings were 19 mm against Staphylococcus aureus and 21 mm against Escherichia coli, respectively.

Traditional antibacterial activity of freshwater microalga Spirulina platensis to aquatic pathogens

2011 ◽  
Vol 43 (9) ◽  
pp. 1287-1295 ◽  
Author(s):  
Jyotirmayee Pradhan ◽  
Basanta Kumar Das ◽  
Swagatika Sahu ◽  
Nilima Priyadarshini Marhual ◽  
Anil K Swain ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Spirulina Platensis ◽  
Aquatic Pathogens

scholarly journals Haemato-immunological responses and effectiveness of feed-based bivalent vaccine against Streptococcus iniae and Aeromonas hydrophila infections in hybrid red tilapia (Oreochromis spp.)

2020 ◽  
Author(s):  
Md. Shirajum Monir ◽  
Md Sabri bin Mohd Yusoff ◽  
Zarirah binti Mohamed Zulperi ◽  
Hasliza binti Abu Hassim ◽  
Aslah Mohamad ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Post Infection ◽  
Serum Antibody ◽  
Economic Losses ◽  
Control Group ◽  
Streptococcus Iniae ◽  
Post Vaccination ◽  
Bivalent Vaccine ◽  
Red Tilapia ◽  
Immunological Responses

Abstract Background Streptococcosis and Motile Aeromonad Septicemia (MAS) are important diseases of tilapia, Oreochromis spp. and causes huge economic losses in aquaculture globally. The feed-based vaccination may be an alternative to minimize major infectious diseases in tilapia. Thus, this study aims to evaluate the haemato-immunological responses and effectiveness of a newly developed feed-based killed bivalent vaccine against Streptococcus iniae and Aeromonas hydrophila in hybrid red tilapia. A total of 495 hybrid red tilapia of 61.23±4.95 g were distributed into 5 groups (each with triplicate). The fish were immunized orally through bivalent (combined S. iniae and A. hydrophila ) spray vaccine (BS group), bivalent formulate vaccine (BF group), monovalent S. iniae vaccine (MS group), monovalent A. hydrophila vaccine (MA group) and unvaccinated as a control group. The vaccine was orally administered on days 0, 14 and 42 applied feed-based bacterin at 5% body weight. The blood and spleen samples were collected from all groups on 7, 21 and 49 days post-vaccination, and also 96 hours post-infection to assess their haemato-immune responses. Results Compared with the unvaccinated group, leukocyte, lymphocytes, monocytes, granulocytes counts in vaccinated groups were significantly ( P < 0.05) increased on 21, 49 days post-vaccination and also 96 hours post-infection, while erythrocytes, haemoglobin and haematocrit in vaccinated groups were significantly ( P < 0.05) enhanced only 96 hours post-infection. Additionally, the lysozyme and phagocytic activity and, serum antibody (IgM) were significantly higher ( P < 0.05) against S. iniae and A. hydrophila in vaccinated groups compared to the unvaccinated group in the pre- and post-infection. Results from the challenge through co-infection with S. iniae and A. hydrophila showed the relative percent survival (RPS) in BF group was 76.37±5.14%, which had the capacity to induce significant protection ( P < 0.05) compared to others groups. Conclusions This study demonstrates the bivalent formulate (BF) group could elicit significant non-specific and specific immunological responses with higher protection in hybrid red tilapia. In addition, this newly developed feed-based bivalent vaccination can be a promising technique for effective and large scale fish immunization in the aquaculture industry.

scholarly journals Effectiveness of Dunaliella salina Extracts against Bacillus subtilis and Bacterial Plant Pathogens

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 613
Author(s):  
Alfredo Ambrico ◽  
Mario Trupo ◽  
Rosaria Magarelli ◽  
Roberto Balducchi ◽  
Angelo Ferraro ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Pseudomonas Syringae ◽  
Dunaliella Salina ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Economic Losses ◽  
Tomato Plants ◽  
Hexane Extracts

Several bacteria pathogens are responsible for plant diseases causing significant economic losses. The antibacterial activity of Dunaliella salina microalgae extracts were investigated in vitro and in vivo. First, biomass composition was chemically characterized and subjected to extraction using polar/non-polar solvents. The highest extraction yield was obtained using chloroform:methanol (1:1 v/v) equal to 170 mg g−1 followed by ethanol (88 mg g−1) and hexane (61 mg g−1). In vitro examination of hexane extracts of Dunaliella salina demonstrated antibacterial activity against all tested bacteria. The hexane extract showed the highest amount of β-carotene with respect to the others, so it was selected for subsequent analyses. In vivo studies were also carried out using hexane extracts of D. salina against Pseudomonas syringae pv. tomato and Pectobacterium carotovorum subsp. carotovorum on young tomato plants and fruits of tomato and zucchini, respectively. The treated young tomato plants exhibited a reduction of 65.7% incidence and 77.0% severity of bacterial speck spot disease. Similarly, a reduction of soft rot symptoms was observed in treated tomato and zucchini fruits with a disease incidence of 5.3% and 12.6% with respect to 90.6% and 100%, respectively, for the positive control.

Characterization of a Bacillus velezensis with antibacterial activity and inhibitory effect on common aquatic pathogens

Aquaculture ◽  
2020 ◽  
Vol 523 ◽  
pp. 735165 ◽  
Author(s):  
Xixi Li ◽  
Xiaojian Gao ◽  
Shuangming Zhang ◽  
Ziyan Jiang ◽  
Hui Yang ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Effect ◽  
Bacillus Velezensis ◽  
Aquatic Pathogens

scholarly journals Hemolysin, Protease, and EPS Producing PathogenicAeromonas hydrophilaStrain An4 Shows Antibacterial Activity against Marine Bacterial Fish Pathogens

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Anju Pandey ◽  
Milind Naik ◽  
Santosh Kumar Dubey
Keyword(s):  
Antibacterial Activity ◽  
Aeromonas Hydrophila ◽  
Pathogenic Bacteria ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Antibacterial Properties ◽  
Cell Extract ◽  
Extracellular Proteins ◽  
Butylated Hydroxytoluene ◽  
Crude Cell Extract

A pathogenicAeromonas hydrophilastrain An4 was isolated from marine catfish and characterized with reference to its proteolytic and hemolytic activity along with SDS-PAGE profile (sodium dodecyl sulphate-Polyacrylamide gel electrophoresis) of ECPs (extracellular proteins) showing hemolysin (approximately 50 kDa). Agar well diffusion assay using crude cell extract of the bacterial isolate clearly demonstrated antibacterial activity against indicator pathogenic bacteria,Staphylococcus arlettaestrain An1,Acinetobactersp. strain An2,Vibrio parahaemolyticusstrain An3, andAlteromonas aurentiaSE3 showing inhibitory zone >10 mm well comparable to common antibiotics. Further GC-MS analysis of crude cell extract revealed several metabolites, namely, phenolics, pyrrolo-pyrazines, pyrrolo-pyridine, and butylated hydroxytoluene (well-known antimicrobials). Characterization of EPS using FTIR indicated presence of several protein-related amine and amide groups along with peaks corresponding to carboxylic and phenyl rings which may be attributed to its virulent and antibacterial properties, respectively. Besides hemolysin, EPS, and protease,Aeromonas hydrophilastrain An4 also produced several antibacterial metabolites.

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