scholarly journals Inhibition of Fish Pathogenic Aeromonas hydrophila and Edwardsiella tarda by Centella asiatica In-vitro

2018 ◽  
Vol 09 (02) ◽  
Author(s):  
Soumyadip Purkait ◽  
Thangapalam Jawahar Abraham ◽  
Sutanu Karmakar ◽  
Biswadeep Dey ◽  
Anwesha Roy
Keyword(s):  
Aeromonas Hydrophila ◽  
Centella Asiatica ◽  
Edwardsiella Tarda

scholarly journals Enterococcus, Myroides Y Exiguobacterium: GÉNEROS BACTERIANOS CON POTENCIAL PROBIÓTICO PARA EL CULTIVO DE TILAPIA NILÓTICA (Oreochromis niloticus)

2017 ◽  
Vol 22 (3) ◽  
pp. 331-339 ◽  
Author(s):  
Luisa Marcela Villamil Díaz ◽  
Daniel Esguerra Rodríguez
Keyword(s):  
16S Rrna ◽  
Enterococcus Faecalis ◽  
Streptococcus Agalactiae ◽  
Aeromonas Hydrophila ◽  
Oreochromis Niloticus ◽  
Edwardsiella Tarda ◽  
Tilapia Nilotica ◽  
Myroides Odoratimimus

Se aislaron 120 morfotipos bacterianos de intestino de tilapia y se seleccionaron según su actividad antibacteriana contra patógenos como Aeromonas hydrophila, Streptococcus agalactiae y Edwardsiella tarda, su capacidad de adherencia a mucus intestinal y cinética de crecimiento. Las bacterias seleccionadas se identificaron mediante secuenciación de 16S rRNA y se identificaron como Exigobacterium sp. I9, Enterococcus faecalis I15 y Myroides odoratimimus I19. Además, se evaluó su efecto in vivo sobre el crecimiento de los peces, mediante su adición al alimento de juveniles de Oreochromis niloticus (106 UFC / g, por 15 días). Se determinó la supervivencia luego de un desafío experimental con Edwardsiella tarda por inyección intraperitoneal (100 µL 105 UFC / mL). Las tres bacterias seleccionadas incrementaron la tasa de crecimiento específica, redujeron la mortalidad de los peces durante el desafío experimental con E. tarda y no causaron mortalidad durante la adición en el alimento. Los efectos positivos in vivo se relacionan posiblemente con actividad in vitro; sin embargo, por motivos de bioseguridad se recomienda efectuar estudios posteriores a Exigobacterium sp. I9y E. faecalis I15 dado que se han reportado miembros de este género como causantes de mortalidad en peces, mientras que en el caso de M. odoratimimus I19, es necesario efectuar futuros estudios para verificar su actividad positiva a mayor escala productiva.

scholarly journals Evaluation of the efficacies of selected antibiotics and medicinal plants on common bacterial fish pathogens

1970 ◽  
Vol 7 (1) ◽  
pp. 163-168 ◽  
Author(s):  
T Rahman ◽  
MMR Akanda ◽  
MM Rahman ◽  
MBR Chowdhury
Keyword(s):  
Medicinal Plants ◽  
Aeromonas Hydrophila ◽  
Control Measure ◽  
Edwardsiella Tarda ◽  
Effective Control ◽  
Fish Pathogens ◽  
Different Doses ◽  
Fresh Culture ◽  
Silver Barb

An experiment was conducted to compare the efficacies of some selected antibiotics and medicinal plants against common bacterial fish pathogens viz., Aeromonas hydrophila, Pseudomonas fluorescens and Edwardsiella tarda. Four different antibiotics viz., CFCIN (ciprofloxacin), Renamycin (oxytetracycline), DT-10 (doxycicline) and Sulfatrim (sulphadiazine + trimethoprim) were exposed in different doses (100, 75, 50 and 25 ppm) to the culture of freshly isolated bacteria under the in vitro condition for sensitivity test and minimum inhibitory dose (MID) was determined. Based on in vitro results, antibiotics were applied to the experimental infection of Thai silver barb, Barbonymus gonionotus. CFCIN showed the best result with 100% recoveries of challenged fish in prolonged bath treatment. Medicinal plants were selected on the basis of previous studies. Crude extracts were prepared from various parts (leaves and bulb) of garlic, turmeric, akand and neem and four different doses were applied to the fresh culture of pathogenic isolates under the in-vitro condition to determine minimum inhibitory dose (MID). However, garlic offered the best result with 90.00 ± 2.89% recoveries of challenged fish in aquarium trial. Akand + neem, turmeric and akand showed moderate to weak recovery rates with the same dose. The present study thus showed that medicinal plants would be an effective control measure along with antibiotics against bacterial fish diseases. Keywords: Efficacy; Medicinal plants; Bacterial fish pathogens DOI: 10.3329/jbau.v7i1.4980 J. Bangladesh Agril. Univ. 7(1): 163-168, 2009

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 Attenuation of Aeromonas hydrophila Infection in Carassius auratus by YtnP, a N-acyl Homoserine Lactonase from Bacillus licheniformis T-1

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 631
Author(s):  
Mengfan Peng ◽  
Wentao Tong ◽  
Zhen Zhao ◽  
Ling Xiao ◽  
Zhaoyue Wang ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Bacillus Licheniformis ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Carassius Auratus ◽  
Quorum Quenching ◽  
Inhibition Rate ◽  
Sequence Identity

In this experiment, the quorum quenching gene ytnP of Bacillus licheniformis T-1 was cloned and expressed, and the effect against infection of Aeromonas hydrophila ATCC 7966 was evaluated in vitro and vivo. The BLAST results revealed a 99% sequence identity between the ytnP gene of T-1 and its homolog in B.subtilis sub sp. BSP1, and the dendroGram showed that the similarity in the YtnP protein in T-1 was 100% in comparison with B.subtilis 3610, which was categorized as the Aidc cluster of the MBL family. The AHL lactonase activity of the purified YtnP was detected as 1.097 ± 0.7 U/mL with C6-HSL as the substrate. Otherwise, purified YtnP protein could significantly inhibit the biofilm formation of A.hydrophila ATCC 7966 with an inhibition rate of 68%. The MIC of thiamphenicol and doxycycline hydrochloride against A. hydrophila reduced from 4 μg/mL and 0.5 μg/mL to 1 μg/mL and 0.125 μg/mL, respectively, in the presence of YtnP. In addition, YtnP significantly inhibited the expression of five virulence factors hem, ahyB, ast, ep, aerA of A. hydrophila ATCC 7966 as well (p < 0.05). The results of inhibition on virulence showed a time-dependence tendency, while the strongest anti-virulence effects were within 4–24 h. In vivo, when the YtnP protein was co-injected intraperitoneally with A. hydrophila ATCC 7966, it attenuated the pathogenicity of A. hydrophila and the accumulated mortality was 27 ± 4.14% at 96 h, which was significantly lower than the average mortality of 78 ± 2.57% of the Carassius auratus injected with 108 CFU/mL of A. hydrophila ATCC 7966 only (p < 0.001). In conclusion, the AHL lactonase in B. licheniformis T-1 was proven to be YtnP protein and could be developed into an agent against infection of A. hydrophila in aquaculture.

scholarly journals Cross-talk among flesh-eating Aeromonas hydrophila strains in mixed infection leading to necrotizing fasciitis

2016 ◽  
Vol 113 (3) ◽  
pp. 722-727 ◽  
Author(s):  
Duraisamy Ponnusamy ◽  
Elena V. Kozlova ◽  
Jian Sha ◽  
Tatiana E. Erova ◽  
Sasha R. Azar ◽  
...  
Keyword(s):  
Necrotizing Fasciitis ◽  
Mixed Infection ◽  
Aeromonas Hydrophila ◽  
Case Fatality ◽  
Host Immune System ◽  
Complex Interactions ◽  
Solid Media ◽  
Multiple Strains ◽  
Highly Virulent

Necrotizing fasciitis (NF) caused by flesh-eating bacteria is associated with high case fatality. In an earlier study, we reported infection of an immunocompetent individual with multiple strains of Aeromonas hydrophila (NF1–NF4), the latter three constituted a clonal group whereas NF1 was phylogenetically distinct. To understand the complex interactions of these strains in NF pathophysiology, a mouse model was used, whereby either single or mixed A. hydrophila strains were injected intramuscularly. NF2, which harbors exotoxin A (exoA) gene, was highly virulent when injected alone, but its virulence was attenuated in the presence of NF1 (exoA-minus). NF1 alone, although not lethal to animals, became highly virulent when combined with NF2, its virulence augmented by cis-exoA expression when injected alone in mice. Based on metagenomics and microbiological analyses, it was found that, in mixed infection, NF1 selectively disseminated to mouse peripheral organs, whereas the other strains (NF2, NF3, and NF4) were confined to the injection site and eventually cleared. In vitro studies showed NF2 to be more effectively phagocytized and killed by macrophages than NF1. NF1 inhibited growth of NF2 on solid media, but ExoA of NF2 augmented virulence of NF1 and the presence of NF1 facilitated clearance of NF2 from animals either by enhanced priming of host immune system or direct killing via a contact-dependent mechanism.

In vitro modulatory effects of Andrographis paniculata, Centella asiatica and Orthosiphon stamineus on cytochrome P450 2C19 (CYP2C19)

2011 ◽  
Vol 133 (2) ◽  
pp. 881-887 ◽  
Author(s):  
Yan Pan ◽  
Badrul Amini Abd-Rashid ◽  
Zakiah Ismail ◽  
Rusli Ismail ◽  
Joon Wah Mak ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Centella Asiatica ◽  
Andrographis Paniculata ◽  
Orthosiphon Stamineus ◽  
Cytochrome P450 2C19

scholarly journals STUDI BACILLUS FIRMUS SEBAGAI KANDIDAT PROBIOTIK DALAM MENGHADAPI Aeromonas hydrophila PADA MEDIA BUDIDAYA The Study of Bacillus firmus as Probiotic Candidate in Supressing Aeromonas hydrophila in Culture Media

2016 ◽  
Vol 11 (2) ◽  
pp. 111
Author(s):  
Alfabetian Harjuno Condro Haditomo ◽  
Angela Mariana Lusiastuti ◽  
Widanarni Widanarni
Keyword(s):  
Aeromonas Hydrophila ◽  
Pathogenic Bacteria ◽  
Culture Media ◽  
Inhibition Zone ◽  
Probiotic Bacteria ◽  
Bacterial Disease ◽  
Second Phase ◽  
Bacillus Firmus ◽  
Culture Methods

ABSTRAK   Pengendalian penyakit bakterial yang umum dilakukan dengan pemakaian antibiotik atau  bahan kimia sudah tidak diperbolehkan lagi karena menimbulkan patogen yang resisten  terhadap bahan kimia tersebut, terlebih jika penggunaan tidak sesuai dengan anjuran yang diberikan. Dampak negatif terhadap kesehatan konsumen berupa residu antibiotik juga menjadi pertimbangan yang harus diperhatikan. Manipulasi terhadap populasi mikroba yang berada di perairan guna pencegahan sebelum terjadinya serangan bakteri yang bersifat mematikan perlu dilakukan sebagaimana konsep probiotik sebagai biokontrol. Tujuan penelitian ini adalah menguji kandidat probiotik dalam menekan atau menghambat bakteri patogen Aeromonas hydrophila. Penelitian ini dilaksananakan dalam dua tahap. Tahap pertama adalah tahap pengujian bakteri kandidat probiotik secara in vitro menggunakan metode zona hambat dan kultur bersama pada media agar.  Tahap kedua adalah uji tentang bakteri kandidat probiotik dengan patogen pada media budidaya. Hasil terbaik penelitian tahap pertama pada  uji kultur bersama antara kandidat probiotik B. firmus dengan A. hydrophila pada skala in vitro adalah dengan penambahan probiotik  B. firmus sebanyak 108 cfu/ml. Sedangkan pada penelitian tahap kedua didapatkan hasil berturut-turut perlakuan D dengan tingkat kelangsungan hidup (SR) mencapai 90%, perlakuan C dengan SR 75%, perlakuan A dengan SR 50% dan perlakuan K dengan SR 50%.   Kata kunci: Bacillus firmus, probiotik, Aeromonas hydrophila, media budidaya   ABSTRACT  Controlling bacterial disease with the use of antibiotics or chemicals is no longer allowed as it results in pathogens that are resistant to the chemicals, especially when not in accordance with the recommendations provided. The negative impactsof the antibiotics residues on the consumers’ health  also need to be considered. Manipulation of microbial populations present in the waters as preventation before the lethal attack of bacteria needs to be done which is in accordance with the concept of probiotics as biocontrol.The purpose of this study was to test the probiotic candidates in suppressing or inhibiting pathogenic bacteria Aeromonas hydrophila. This study was conducted in two stages. The first stage was to test a candidate probiotic bacteria in vitro using culture methods and inhibition zone on the media together. The second stage wasto test candidate probiotic bacteria to pathogens on the cultivation media. The best results in the first phase of the research is shared culture test between probiotic candidate B. FIRMUS with A. hydrophila on vitro scale is the addition of the probiotic B. FIRMUS 108 cfu / ml. While in the second phase of the research results obtained successively: treatment D with a survival rate (SR) reaches 90%, treatment C with SR 75%, treatment A with SR 50% and treatment K with SR 50%. Keywords: Bacillus FIRMUS, probiotics, Aeromonas hydrophila, media cultivation

scholarly journals Structural Insight Into Aeromonas Hydrophila AHL Synthase AhyI Driving Acyl-ACP Selective Recognition

2021 ◽  
Author(s):  
Lei Jin ◽  
Yu chen ◽  
Wenge Yang
Keyword(s):  
Aeromonas Hydrophila ◽  
Acyl Chain ◽  
Virulence Gene ◽  
Kinetic Studies ◽  
Homoserine Lactone ◽  
Selective Recognition ◽  
Acyl Donor ◽  
Virulence Gene Expression ◽  
Long Chain

Abstract Background: The gram-negative bacterium Aeromonas hydrophila as the major causative agent of the fish disease motile aeromonad septicemia, uses N-acyl-homoserine lactone quorum sensing signals to coordinate biofilm formation, motility and virulence gene expression in pathogens. Thus, AHL signaling pathway is considered as a therapeutic target against pathogenic A. hydrophila infection. AHL autoinducers biosynthesis in A. hydrophila are specifically catalyzed by an ACP-dependent AHL synthase AhyI using SAM and acyl-ACP as the precursors. Our previously reported AhyI protein heterologously expressed in E. coli strain showed the production characteristics of medium-long chain AHLs, although AhyI was only considered as a short-chain C4/C6-HSL synthase during the past two decades.Results: In this study, we carried out the in vitro biosynthetic assays of six AHL molecules and kinetic studies of recombinant AhyI with a panel of four linear acyl-ACPs. These resulting data all indicate that C4/C6-ACP are the native acyl substrates for AhyI against acyl-ACPs with longer linear chains as the non-native acyl donor. In an effort to further understand AhyI acyl-donor substrates preferences, we performed a structural comparison of three ACP-dependent LuxI homologs (TofI, BmaI1 and AhyI), and identified three key hydrophobic residues (I67, F125 and L157) as part of the acyl-chain binding pocket that confer AhyI to selectively recognize native C4/C6-ACP substrates. The predictions were further supported by computational Ala mutation assay.Conclusions: Our current studies redefined AhyI protein that is a multiple short- to long-chain AHL molecules synthase with longer acyl-ACPs (C8~C14) as the non-native substrates, and we also theorized that with knowledge of the key residues in AHL signal synthase AhyI to drive acyl-ACP selective recognition.

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