scholarly journals Symbiotic bacteria associated to Prosthechea citrina, a Mexican endemic orchid

2020 ◽  
Vol 38 (3) ◽  
Author(s):  
Tomasita Santiago-Gerónimo ◽  
Héctor Lozoya-Saldaña ◽  
María Lourdes Rodríguez-Mejía
Keyword(s):  
Aeromonas Hydrophila ◽  
Symbiotic Bacteria

En el proceso de cultivo <em>in vitro</em> de tejidos de plantas, se presentan microorganismos potencialmente fitopatógenos y/o aparentemente contaminantes, que eventualmente ocasionan perdidas de material vegetal. La presente investigación tuvo como objetivo identificar a bacterias endófitas asociadas a <em>Prosthechea citrina</em>, una orquídea endémica de México, mediante el aislamiento, cultivo<em> in vitro</em> y secuenciación del gen 16S del ARN ribosomal de las cepas bacterianas. Se identificaron a <em>Aeromonas hydrophila</em> y <em>Enterobacter</em> sp. como simbiontes, no patogénicos, del bulbo y de base de hoja y a <em>A. hydrophila</em> en la parte media y el ápice foliar. Se evaluaron cuatro antibióticos para su control<em> in vitro</em> mediante el método de disco-placa, cuantificando el diámetro de crecimiento de la colonia. El mayor halo de inhibición, con significancia estadística, se obtuvo con oxitetraciclina para <em>A. hydrophila</em> y con ampicilina para <em>Enterobacter</em> sp. Se demuestra la presencia de bacterias endófitas, con especificidad de ubicación en el tejido, así como el antibiótico correspondiente que las inhibe.

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.

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.

scholarly journals Identification and characterization of virulent Aeromonas hydrophila Ah17 from infected Channa striata in river Cauvery and in vitro evaluation of shrimp chitosan

2020 ◽  
Vol 8 (2) ◽  
pp. 1272-1283 ◽  
Author(s):  
Vignesh Samayanpaulraj ◽  
Muthukumar Sivaramapillai ◽  
Sankara Naynar Palani ◽  
Krishnaveni Govindaraj ◽  
Vijay Velu ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
In Vitro Evaluation ◽  
Channa Striata ◽  
Virulent Aeromonas Hydrophila ◽  
Identification And Characterization

Dominant symbiotic bacteria associated with wild medfly populations reveal a bacteriocin-like killing phenotype: a ‘cold-case’ study

2019 ◽  
Vol 110 (4) ◽  
pp. 457-462
Author(s):  
Silvia Ciolfi ◽  
Laura Marri
Keyword(s):  
Bacterial Species ◽  
Klebsiella Oxytoca ◽  
Pcr Amplification ◽  
Fruit Trees ◽  
Antagonistic Activity ◽  
Culture Collection ◽  
Symbiotic Bacteria ◽  
Bacterial Populations

AbstractThe gut of the agricultural pest Ceratitis capitata hosts a varied community of bacteria, mainly Enterobacteriaceae, that were implicated in several processes that increase the fitness of the insect. In this study, we investigated the antagonistic activity in vitro of Klebsiella oxytoca strains isolated in the 1990s from the alimentary tract of wild medflies collected from different varieties of fruit trees at diverse localities. Assays were carried out against reference strains (representative of Gram-negative and -positive bacterial species) of the American Type Culture Collection (ATCC). Eight Klebsiella, out of 11, expressed a killing activity against Escherichia coli ATCC 23739, and Enterobacter cloacae ATCC 13047; among the eight strains, at least one showed activity against Salmonella typhimurium ATCC 23853. Genomic DNA derived from all Klebsiella strains was then subjected to PCR amplification using specific primer pairs designed from each of the four bacteriocin (KlebB, C, D, CCL) sequences found so far in Klebsiella. KlebD primer pairs were the only to produce a single product for all strains expressing the killing phenotype in vitro. One of the amplicons was cloned and sequenced; the DNA sequence shows 93% identity with a plasmid-carried colicin-D gene of a strain of Klebsiella michiganensis, and 86% identity with the sequence encoding for the klebicin D activity protein in K. oxytoca. Our work provides the first evidence that dominant symbiotic bacteria associated with wild medfly populations express a killing phenotype that may mediate inter and intraspecies competition among bacterial populations in the insect gut in vivo.

scholarly journals Atividade antimicrobiana in vitro de extratos etanólicos de própolis de três estados brasileiros sobre Aeromonas hydrophila isoladas de peixes

2012 ◽  
Vol 79 (1) ◽  
pp. 9-15
Author(s):  
N.P.C. Andrade ◽  
E.M.S da Silva ◽  
R.A. Mota ◽  
J.L.A. Veschi ◽  
M.F. Ribeiro ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Minas Gerais ◽  
Para Determinar

O presente estudo teve como objetivo avaliar a sensibilidade in vitro de Aeromonas hydrophila frente a extratos etanólicos de própolis (uma verde e duas marrons) obtidos em três estados brasileiros (Minas Gerais, Ceará e Pernambuco). Para verificar a atividade antimicrobiana in vitro da própolis, 15 isolados de A. hydrophila foram testados para determinar a Concentração Bactericida Mínima (CBM) dos extratos. Curvas de sobrevivência para o crescimento bacteriano foram determinadas pela incubação dos isolados em extratos etanólicos de própolis a 15% por 24 horas. As médias da CBM dos extratos de própolis foram 1,68% para a própolis verde, 2,31% para a própolis marrom do Ceará e 3,75% para a própolis marrom de Pernambuco. A curva de sobrevivência dos isolados demonstrou uma inibição parcial com até três horas de incubação. Este resultado é compatível com o efeito bacteriostático da própolis, o que pode ser de interesse para a terapia em aquicultura, como alternativa às poucas drogas antimicrobianas disponíveis.

Sulfated galactan from Halymenia dilatata enhance the antioxidant properties and prevents Aeromonas hydrophila infection in tilapia fish: In vitro and in vivo study

2020 ◽  
Vol 158 ◽  
pp. 569-579
Author(s):  
Manoharan Vinosha ◽  
Subramanian Palanisamy ◽  
Ravichandran Anjali ◽  
Changsheng Li ◽  
Khamphone Yelithao ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Antioxidant Properties ◽  
In Vivo Study ◽  
Sulfated Galactan
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