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vibrio harveyi

Alyssa S Ball, Julia C van Kessel
In Vibrio species, quorum sensing controls gene expression for numerous group behaviors, including bioluminescence production, biofilm formation, virulence factor secretion systems, and competence. The LuxR/HapR master quorum sensing regulators activate expression of hundreds of genes in response to changes in population densities. The mechanism of transcription activation by these TetR-type transcription factors is unknown, though LuxR DNA binding sites that lie in close proximity to the -35 region of the promoter are required for activation at some promoters...
February 11, 2019: Molecular Microbiology
Noorashikin Md Noor, Tom Defoirdt, Norfarrah Alipiah, Murni Karim, Hassan Daud, Ikhsan Natrah
The link between quorum sensing in Vibrio campbellii and its virulence towards tiger grouper (Epinephelus fuscoguttatus) was investigated using V. campbellii wild type and quorum-sensing mutants with inactive quorum sensing or constitutively maximal quorum-sensing activity, and signal molecule synthase mutants. The results showed that wild-type V. campbellii is pathogenic to grouper larvae, causing more than 50% mortality after 4 days of challenge. Furthermore, the mortality of larvae challenged with the mutant with maximally active quorum sensing was significantly higher than that of larvae challenged with the wild type, whereas a higher survival was observed in the larvae challenged to the mutant with a completely inactive quorum-sensing system...
February 11, 2019: Journal of Fish Diseases
María Auxiliadora Sotomayor, Jessica Karina Reyes, Leda Restrepo, Cristóbal Domínguez-Borbor, Martha Maldonado, Bonny Bayot
Bacterial diseases cause high mortality in Penaeus (Litopenaeus) vannamei postlarvae. Therefore, appropriate application of efficient therapeutic products is of vital importance for disease control. This study evaluated through in vitro analyses the antimicrobial effectiveness of commercial therapeutic products used for P. vannamei bacterial diseases and antibiotics against pathogenic Vibrio strains circulating in Ecuadorian hatcheries. Twenty strains were isolated from 31 larvae samples with high bacterial counts from 10 hatcheries collected during mortality events...
2019: PloS One
Itxaso Montánchez, Elixabet Ogayar, Ander Hernández Plágaro, Anna Esteve-Codina, Jèssica Gómez-Garrido, Maite Orruño, Inés Arana, Vladimir R Kaberdin
Discovering the means to control the increasing dissemination of pathogenic vibrios driven by recent climate change is challenged by the limited knowledge of the mechanisms in charge of Vibrio spp. persistence and spread in the time of global warming. To learn about physiological and gene expression patterns associated with the long-term persistence of V. harveyi at elevated temperatures, we studied adaptation of this marine bacterium in seawater microcosms at 30 °C which closely mimicked the upper limit of sea surface temperatures around the globe...
January 22, 2019: Scientific Reports
Nurliyana Mohamad, Muskhazli Mustafa, Mohammad Noor Amal Azmai, Mohd Zamri Saad, Ina Salwany Md Yasin, Nurhidayu Al-Saari
This study investigates the environmental factors associated with the presence of Vibrionaceae in economically important cage-cultured tropical marine fish; the Asian Seabass, Red Snapper and Hybrid Grouper. Fish samplings were conducted at monthly intervals between December 2016 and August 2017. The body weight and length of individual fish were measured, while the skin, eye, liver and kidney were sampled for bacterial isolation and identification. Water physico-chemical parameters during the sampling activities were determined, and the enumeration of total Vibrionaceae count was also conducted from water and sediment samples...
January 17, 2019: Journal of Aquatic Animal Health
G B Zavilgelsky, R S Shakulov
The origin of bioluminescence in living organisms was first mentioned by Charles Darwin (1859) and remains obscure despite significant success achieved over the past decades. Here we discuss the mechanisms of bacterial bioluminescence. We have the main results from structural and functional analysis of the genes of lux operons, enzymes (luciferase), and mechanisms of bioluminescence in several species of marine bacteria, which belong to three genera, Vibrio, Aliivibrio, and Photobacterium (A. fischeri, V. harveyi, P...
November 2018: Molekuliarnaia Biologiia
Lei Guo, Fei Zhang, Xintong Wang, Hui Chen, Qianqian Wang, Jiacai Guo, Xi Cao, Le Wang
This study investigated the antibacterial activity and mechanism of questin from marine Aspergillus flavipes HN4-13 against aquatic pathogenic Vibrio harveyi . The minimal inhibitory concentration and minimal bactericidal concentration of questin against V. harveyi strain SZ-1 and 1.8690 were determined by Oxford cup and tube dilution methods. The mechanism of action of questin against V. harveyi 1.8690 was investigated by bacterial growth curve analysis, ultraviolet absorption, Mo-Sb-Vc colorimetry, alkaline phosphatase and scanning electron microscopy...
January 2019: 3 Biotech
Watcharin Chumjan, Mathias Winterhalter, Wipa Suginta
BACKGROUND: VhChiP is a sugar-specific-porin present in the outer membrane of the marine bacterium Vibrio harveyi and responsible for chitin uptake, with a high selectivity for chitohexaose. METHODS: VhChiP and its mutants were expressed and purified from BL21 (DE3) Omp8 Rosetta strain. After reconstitution into planar lipid bilayers, the ion current fluctuations caused by chitohexaose entering the channel were measured in deuterium oxide and in water. RESULTS: The role of hydrogen-bonding in sugar binding was investigated by comparing channel occlusion by chitohexaose in buffers containing H2 O and D2 O...
December 18, 2018: Biochimica et biophysica acta. Biomembranes
Fanghua Wang, Zongze Wu, Abdelkarim Abousalham, Bo Yang, Yonghua Wang
A novel phospholipase D that originate from marine Vibrio harveyi (VhPLD) was recombinant expressed and biochemically characterized. Moreover, effects of C-terminal peptides on catalytic and interfacial binding properties of VhPLD were investigated by constructing two truncated mutants (VhPLD-Δ(472-483) and VhPLD-Δ(437-483)). Optimal reaction temperature and pH value for wild-type VhPLD (VhPLD-WT) was 45 °C and pH 8.0. However, optimal reaction temperature of VhPLD-Δ(437-483) increased to 50 °C. Meanwhile, catalytic efficiency (kcat /KM ) of VhPLD-Δ(472-483) and VhPLD-Δ(437-483) to the 1,2-Dioctanoyl-sn-glycero-3-phosphatidyl-p-nitrophenol (PpNP) was 12...
December 11, 2018: International Journal of Biological Macromolecules
Eveline Brodl, Andreas Winkler, Peter Macheroux
Bioluminescence refers to the production of light by living organisms. Bioluminescent bacteria with a variety of bioluminescence emission characteristics have been identified in Vibrionaceae , Shewanellaceae and Enterobacteriaceae . Bioluminescent bacteria are mainly found in marine habitats and they are either free-floating, sessile or have specialized to live in symbiosis with other marine organisms. On the molecular level, bioluminescence is enabled by a cascade of chemical reactions catalyzed by enzymes encoded by the lux operon with the gene order luxCDABEG ...
2018: Computational and Structural Biotechnology Journal
Nurliyana Mohamad, Fauzul Aidil Mohd Roseli, Mohammad Noor Amal Azmai, Mohd Zamri Saad, Ina Salwany Md Yasin, Nor Amalina Zulkiply, Nurrul Shaqinah Nasruddin
In September 2016, a marine fish farm operator in Selangor, Malaysia reported a disease outbreak affecting juvenile Hybrid Groupers (Camouflage Grouper Epinephelus polyphekadion x Tiger Grouper E. fuscoguttatus). The average daily mortality was 120 fish, resulting in a cumulative mortality rate of 29% within 10 days. The affected Hybrid Groupers displayed lethargy, excessive mucus production, rotten fins, congestion of livers and kidneys, and enlargement of spleens. Microscopically, there were generalize congestion of the brains and internal organs...
December 7, 2018: Journal of Aquatic Animal Health
Mingkang Chen, Xia Liu, Jing Zhou, Xu Wang, Ruiting Liu, Hongyu Peng, Boyan Li, Zhonglu Cai, Chen Jiang
Galectins are a family of proteins with conserved carbohydrate recognition domains (CRDs) that bind to specific glycans, including the glycans on the surface of pathogens, and therefore play a role in cytokine secretion, cell activation, migration, adhesion and apoptosis. Currently, galectins have been extensively studied in mammalian species but rarely studied in teleost fish species. In this study, a total of 12 galectin genes were characterized to understand the molecular mechanisms of galectin function in Japanese pufferfish (Takifugu rubripes)...
November 27, 2018: Fish & Shellfish Immunology
An Ngoc Nguyen, Elena Disconzi, Guillaume M Charrière, Delphine Destoumieux-Garzón, Philippe Bouloc, Frédérique Le Roux, Annick Jacq
CsrBs are bacterial highly conserved and multiple-copy noncoding small RNAs (sRNAs) that play major roles in cell physiology and virulence. In the Vibrio genus, they are known to be regulated by the two-component system VarS/VarA. They modulate the well-characterized quorum sensing pathway controlling virulence and luminescence in Vibrio cholerae and Vibrio harveyi , respectively. Remarkably, Vibrio tasmaniensis LGP32, an oyster pathogen that belongs to the Splendidus clade, was found to have four copies of csrB , named csrB1-4 , compared to two to three copies in other Vibrio species...
November 28, 2018: MSphere
Zhiming Zhu, Chuanfu Dong, Shaoping Weng, Jianguo He
Vibrio harveyi is a serious pathogen of scale drop and muscle necrosis disease in marine commercial fishes. Adhesion to and colonization of the host cells surfaces is the first and crucial step for pathogenic bacterial infection, which is usually mediated by outer membrane proteins (Omps). The objectives of this study were to identify the major adhesin in Omps that plays the essential role in adhesion of V. harveyi to the host cells, and to assess the potential of this adhesin as a vaccine candidate for V. harveyi infection...
November 16, 2018: Fish & Shellfish Immunology
Yongcan Zhou, Yang Lei, Zhenjie Cao, Xiaojuan Chen, Yun Sun, Yue Xu, Weiliang Guo, Shifeng Wang, Chunsheng Liu
Defensins are a group of small cationic and cysteine-rich peptides that are important components of the innate immune system. However, studies on defensins in teleosts are very limited, particularly studies on defensin functions through in vivo assays. In this study, we cloned and identified one β-defensin (TroBD) the golden pompano, Trachinotus ovatus, and analyzed the functions of TroBD in both in vivo and in vitro assays. TroBD is composed of 63 amino acids and shares high sequence identities (27.27-98...
November 15, 2018: Developmental and Comparative Immunology
Jing Diao, Hongjun Liu, Fawen Hu, Le Li, Xiaolu Wang, Chunlei Gai, Xiaoqing Yu, Ying Fan, La Xu, Haibin Ye
Fat greenling (Hexagrammos otakii) is an important aquaculture fish species in northern China. Unfortunately, Vibrio infections have caused considerable losses to the fat greenling aquaculture industry. However, the study on immune response of fat greenling against Vibrio species has not been reported yet. In this paper, the immune response of fat greenling against V. harveyi at gene expression level was studied by transcriptome analysis. A total of 189753 high-quality unigenes with a N50 length of 672bp were obtained by transcriptome profiling, which provided abundant data for the future study of fat greenling...
October 25, 2018: Fish & Shellfish Immunology
Biao Han, Vaneet Inder Kaur, Kartik Baruah, Viet Dung Nguyen, Peter Bossier
Ascorbate is an essential nutrient commonly regarded as an antioxidant. In this study, using axenic brine shrimp and pathogenic strain Vibrio harveyi as the host-pathogen model, we confirmed that pretreatment of sodium ascorbate (NaAs), at an optimum concentration, was a prooxidant by generation of hydrogen peroxide, inducing protective effects in the brine shrimp against V. harveyi infection. Such a protective effect could be neutralized by the addition of an antioxidant enzyme catalase. We further showed that generation of oxygen radicals is linked to the induction of heat shock protein 70 (Hsp70), which is involved in eliciting the antioxidant protection system including superoxidase dismutase (SOD) and possibly many other immune responses...
November 13, 2018: Developmental and Comparative Immunology
Maurilio Lopes Martins, Uelinton Manoel Pinto, Katharina Riedel, Maria Cristina Dantas Vanetti
The 16S rDNA of six psychrotrophic Enterobacteriaceae isolated from cold raw milk were sequenced and the isolate 039 was identified as Pantoea sp., isolates 059, 068, and 071 were identified as Hafnia alvei , 067 was identified as Enterobacter sp., and 099 was identified as Aeromonas hydrophila . They presented different spoilage potentials in milk with A. hydrophila 099 being the most deteriorative. Only Pantoea sp. 039 was not able to induce the quorum sensing monitor strains of acyl homoserine lactones (AHLs)...
2018: BioMed Research International
Xiao-Dong Li, Xin Li, Xiao-Ming Li, Gang-Ming Xu, Yang Liu, Bin-Gui Wang
Four new uncommon 20-nor-isopimarane diterpenoid epimers, aspewentins I-L ( 1 ⁻ 4 ), together with a new methylated derivative of 3 , aspewentin M ( 5 ), were isolated from the deep sea sediment-derived fungus Aspergillus wentii SD-310. The very similar structures of these epimers made the separation and purification procedures difficult. The structures of compounds 1 ⁻ 5 were illustrated based on spectroscopic analysis, and the absolute configurations of compounds 1 ⁻ 5 were unambiguously determined by the combination of NOESY, time-dependent density functional (TDDFT)-ECD calculations, and X-ray crystallographic analysis...
November 9, 2018: Marine Drugs
Ander Hernández Plágaro, Peter B Pearman, Vladimir R Kaberdin
Vibrio harveyi is a Gram-negative pathogenic bacterium ubiquitously present in natural aquatic systems. Although environmental adaptability in V. harveyi may be enabled by profound reprogramming of gene expression previously observed during responses to starvation, suboptimal temperatures and other stress factors, the key characteristics of V. harveyi transcripts and operons, such as their boundaries and size as well as location of small RNA genes, remain largely unknown. To reveal the main features of the V...
November 10, 2018: Genomics
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