Cloning, Characterization, and Antibacterial Properties of Endolysin LysE Against Planktonic Cells and Biofilms of Aeromonas hydrophila

Author(s):  
Pallavi Baliga ◽  
Puneeth Thadooru Goolappa ◽  
Malathi Shekar ◽  
Girisha Shivani Kallappa
2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Anju Pandey ◽  
Milind Naik ◽  
Santosh Kumar Dubey

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.


Author(s):  
Yori Turu Toja ◽  
Eddy Suprayitno ◽  
Aulanni’am ◽  
Uun Yanuhar

Indonesia has many local plants with potential as herbal antibacterial properties, one of which is the local black fruit of Wandama. The objective of this study is to determine the antibacterial activity of the extract of black fruit seed against A. Hydrophila by in vitro and FTIR by Tilapia. The benefit of this research is to make black fruit seed extract as a natural remedy against tilapia attacked by Aeromonas Hydrophila. The antibacterial activity of black fruit seed extract against A. Hydrophila is investigated in vitro and using FTIR on tilapia in this research. The aim of this study is to establish black fruit seed extract as a natural treatment for tilapia infected with Aeromonas Hydrophila. The disc approach was used to conduct the in vitro research. Agar medium was poured into a sterile petri dish, and 2 drops of bacteria from the liquid medium were uniformly distributed and cooled. On the press, disc paper with black fruit seed extract was put and incubated for 18-24 hours at 35 C. An FTS 1000 version spectrophotometer system was used for the FTIR test. For the FT-IR study, a fraction of dried black fruit seeds was used. For clear preparation, 100 mg of dry extract is condensed in KBr pellets. A specimen of loaded black fruit seed samples was analyzed using FT-IR spectroscopy with a scanning range of 400-4000 cm-1 and a resolution of 4 cm-1. The results showed that the ethyl acetate fraction produced an inhibition zone (13.65 mm), the water fraction produced an inhibition zone (11.21 mm), and the n-hexane fraction produced the weakest inhibition zone (11.21 mm) (5.31mm). The concentration test results from 125 ppm, 250 ppm, 500 ppm and 1000 ppm obtained a large inhibition zone at a concentration of 1000 ppm with an inhibition zone area of 11.43 + 0.02. The absorbance value of black fruit seed extract in ethyl acetate solvent at 3430 cm-1 revealed the absorption band with the strongest vibration of the hydroxylate (-OH) functional group, according to FTIR research. Final thoughts with an average value of 13.65 + 0.06, black fruit seed extract using ethyl acetate can inhibit A. Hydrophila bacteria.


2021 ◽  
Author(s):  
Mingming H ◽  
Chenxi Zhu ◽  
Zakaria Zuraini ◽  
Tianheng Gao ◽  
Ying Yang ◽  
...  

The innate immune response of Charybdis japonica treated with Aeromonas hydrophila was explored using bioinformatics. Metabolomics data were integrated with a gut microbial 16S rRNA dataset, together with information on corresponding enzyme activity. The results of the study showed that after being infected with A. hydrophila, some beneficial genera of bacteria in the gut of C. japonica, such as Photobacterium, Rhodobacter, Polaribacter, Psychrilyobacter, Mesoflavibacter, Fusibacter and Phormidium, could directly inhibit Vibrio or produce extracellular polysaccharides with highly effective antibacterial properties. The intestinal probiotics of C. japonica such as Mesoflavibacter have a mutually reinforcing relationship with Phaeobacter, Colwellia, Bacillus, Psychrobacter and Cohaesibacter. Conditional pathogenic bacteria in the gut of healthy crabs may also have such a symbiotic relationship with intestinal probiotics, promoting their growth and reproduction. For example, Phormidium has a mutualistic relationship with Aeromonas and Azopira. Metabolites in the gut of C. japonica infected with A. hydrophila, including beta-alanine metabolism, nitrogen metabolism, inositol phosphate metabolism, galactose metabolism, histidine metabolism, ascorbate and arginine and proline metabolism were increased, with alanine metabolism being the most abundant. The activity of metabolite related enzymes such as lipid peroxidase, phenoloxidase, superoxide dismutase, nitric oxide synthase, glutathione transferase and mid-glutathione decreased and NO levels also decreased. The positive correlation with the probiotic flora suggests that metabolites increase with bacterial abundance and that microbial metabolites or co-metabolites can, in turn, achieve many pleiotropic effects to resist invasion by A. hydrophila. These results may contribute to further research in the resistance of C. japonica to invading pathogens.


2021 ◽  
Vol 6 (1) ◽  
pp. 41-44
Author(s):  
An’amt Mohamed Noor ◽  
Nurul Farah Amanina Yusoff ◽  
Huang Nay Ming ◽  
Zulhisyam Abdul Kari ◽  
Mohammad Khairul Azhar Abdul Razab ◽  
...  

We report a simple and straightforward method for the preparation of graphene oxide-silver aerogel (GOAg) via microwave irradiation. Graphene oxide (GO) was used as a substrate for the growth of silver nanoparticles (AgNPs) and silver complex was used as a precursor. The GOAg were prepared by rapidly expose mixture of GO and silver complexes with microwave for 30 s under an ambient atmosphere. For the nanocomposites, GOAg solution were lyophilized in a freeze-dryer for 24 hours to form an aerogel. The obtained GO and GOAg nanocomposites were characterized by X-ray diffractometer (XRD) and Ultraviolet-visible spectroscopy (UV-Vis). XRD confirmed the formation GO, and GOAg while GOAg display antibacterial properties against Methicillin-resistant Staphylococcus aureus (MRSA) and Aeromonas hydrophila bacteria. We demonstrate


2016 ◽  
Vol 24 (4) ◽  
pp. 219-230 ◽  
Author(s):  
Halyna Tkachenko ◽  
Lyudmyla Buyun ◽  
Elżbieta Terech-Majewska ◽  
Zbigniew Osadowski

Abstract The main goal of this study was to determine in vitro antimicrobial activity of ethanolic extracts obtained from the leaves of various Ficus species against Aeromonas hydrophila isolated locally from infected rainbow trout (Oncorhynchus mykiss Walbaum) with the aim of providing scientific rationale for the use of the plant in the treatment of bacterial infections induced by Aeromonas spp. in fish. Antimicrobial susceptibility testing was done on Muller-Hinton agar with the disc diffusion method. In the present study, most ethanolic extracts proved effective against the A. hydrophila tested, with 10-12 mm inhibition zones observed. A. hydrophila demonstrated the highest susceptibility to F. pumila. Among various species of Ficus with moderate activity against A. hydrophila, the highest antibacterial activities were noted for F. benghalensis, F. benjamina, F. deltoidea, F. hispida, and F. lyrata. Thus, Ficus can be used as a natural antiseptic and antimicrobial agent in veterinary practice. Further investigations need to be conducted to isolate and identify the bioactive compounds that can then be subjected to detailed pharmacological studies and the development of clinical applications. The alarming rate of increasing resistance in bacterial pathogens in aquaculture environments means that medicinal plants with antibacterial properties are very important as natural resources of new active compounds.


2001 ◽  
Vol 64 (2) ◽  
pp. 195-200 ◽  
Author(s):  
LIDIA del C. VELÁZQUEZ ◽  
MARÍA E. ESCUDERO ◽  
ANA MARÍA S. de GUZMÁN

Aeromonas hydrophila is considered to be an emergent food-related bacterium. Phosphates are used as additives, mainly in meat products, to improve the quality of these foods. The antibacterial properties of phosphates are also well known. In this work, two A. hydrophila strains in early exponential phase were used: (A) A. hydrophila ATCC 7965 and (B) A. hydrophila derived from food, isolated in our laboratory. MIC and MBC studies were performed to assess the antibacterial effects of four phosphates assayed in brain heart infusion broth (BHI) and modified complete defined synthetic medium (mCDS) as compared to cooked ground meat medium (CM). The MBC values of the phosphates in CM were significantly higher than MIC values in BHI broth and mCDS medium (P < 0.05). In the two latter media, the growth of both A. hydrophila strains was totally inhibited by concentrations between 0.5 and 3.0%. Although all the assayed phosphates proved to have bactericidal effects on A. hydrophila, 0.5% sodium acid pyrophosphate (SAPP) exhibited greater effects in both strains and was selected for subsequent experiments. The bacteriolytic effect of SAPP was spectrophotometrically determined (260 nm of absorbance) by means of the leakage of intracellular nucleotides and microscopically confirmed by the presence of massive gelatinous aggregates. These were identified by enzymes (RNase, DNase, and proteinase) that hydrolyzed the nucleotides and proteins released during cellular lysis in the presence of SAPP. It was concluded that 0.5% SAPP can have bactericidal and bacteriolytic effects in early exponential phase A. hydrophila cells.


2011 ◽  
Vol 77 (3) ◽  
pp. 375-384 ◽  
Author(s):  
Chunxia Lu ◽  
Hongxin Wang ◽  
Wenping Lv ◽  
Pao Xu ◽  
Jian Zhu ◽  
...  

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