scholarly journals Factors other than metalloprotease are required for full virulence of French Vibrio tubiashii isolates in oyster larvae

Microbiology ◽  
2015 ◽  
Vol 161 (5) ◽  
pp. 997-1007 ◽  
Author(s):  
Rachida Mersni-Achour ◽  
Yosra Ben Cheikh ◽  
Vianney Pichereau ◽  
Ibtissem Doghri ◽  
Cédric Etien ◽  
...  
Keyword(s):  
Vibrio Tubiashii

Exemplar Abstract for Vibrio tubiashii Hada et al. 1984 emend. Dubert et al. 2016.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Vibrio Tubiashii

Nồng độ ức chế tối thiểu (Minimal Inhibitory Concentration - MIC) của một số loại kháng sinh đến vi khuẩn phân lập được từ cá dìa thương phẩm mắc bệnh lở loét (Siganus guttatus, Bloch, 1787)

2015 ◽  
Vol 104 (5) ◽  
Author(s):  
Lê Văn Bảo Duy ◽  
Dương Thị Thủy ◽  
Nguyễn Ngọc Phước ◽  
Trương Thị Hoa ◽  
Nguyễn Đức Quỳnh Anh
Keyword(s):  
Minimal Inhibitory Concentration ◽  
Vibrio Parahaemolyticus ◽  
Inhibitory Concentration ◽  
Vibrio Tubiashii

Nghiên cứu được tiến hành nhằm xác định nồng độ ức chế tối thiểu (Minimal Inhibitory Concentration - MIC) của một số loại kháng sinh đến vi khuẩn phân lập được từ cá dìa thương phẩm mắc bệnh lở loét (Siganus guttatus). Từ kết quả phân lập định danh cho thấy 2 chủng Vibrio parahaemolyticus VPMP22 và Vibrio tubiashii ATCC 19109 có mặt trên các vết lở loét ở cá dìa thương phẩm. Kết quả thử nghiệm MIC cho thấy các loại kháng sinh Cefuroxim, Cefotaxim, Tetracycline, Erythromicin, Rifamicin có nồng độ ức chế vi khuẩn Vibrio parahaemolyticus VPMP22 tốt nhất dưới 0.21 µg/ml. Các kháng sinh có Cefuroxim, Cefotaxim, Oxytetraciline, Erythromicin, Trimethoprim nồng độ ức chế vi khuẩn Vibrio tubiashii ATCC 19109 tốt nhất dưới 1.25 µg/ml. Penicillin có nồng độ ức chế tối thiểu cao nhất đối với cả 2 chủng vi khuẩn trên (80 µg/ml), cho thấy 2 chủng vi khuẩn trên đã có sự kháng thuốc đối với loại kháng sinh này. Do đó, trong phòng trị bệnh lở loét trên cá dìa nên sử dụng Cefuroxim và Cefotaxim để có hiệu quả cao nhất trong phòng trị bệnh.

scholarly journals The Extracellular Metalloprotease of Vibrio tubiashii Is a Major Virulence Factor for Pacific Oyster (Crassostrea gigas) Larvae

2008 ◽  
Vol 74 (13) ◽  
pp. 4101-4110 ◽  
Author(s):  
Hiroaki Hasegawa ◽  
Erin J. Lind ◽  
Markus A. Boin ◽  
Claudia C. Häse
Keyword(s):  
Crassostrea Gigas ◽  
Pacific Oyster ◽  
Vibrio Vulnificus ◽  
Invasive Disease ◽  
High Homology ◽  
Structural Genes ◽  
Vibrio Tubiashii ◽  
Extracellular Products ◽  
Larval Toxicity ◽  
Culture Supernatants

ABSTRACT Vibrio tubiashii is a recently reemerging pathogen of larval bivalve mollusks, causing both toxigenic and invasive disease. Marine Vibrio spp. produce an array of extracellular products as potential pathogenicity factors. Culture supernatants of V. tubiashii have been shown to be toxic to oyster larvae and were reported to contain a metalloprotease and a cytolysin/hemolysin. However, the structural genes responsible for these proteins have yet to be identified, and it is uncertain which extracellular products play a role in pathogenicity. We investigated the effects of the metalloprotease and hemolysin secreted by V. tubiashii on its ability to kill Pacific oyster (Crassostrea gigas) larvae. While V. tubiashii supernatants treated with metalloprotease inhibitors severely reduced the toxicity to oyster larvae, inhibition of the hemolytic activity did not affect larval toxicity. We identified structural genes of V. tubiashii encoding a metalloprotease (vtpA) and a hemolysin (vthA). Sequence analyses revealed that VtpA shared high homology with metalloproteases from a variety of Vibrio species, while VthA showed high homology only to the cytolysin/hemolysin of Vibrio vulnificus. Compared to the wild-type strain, a VtpA mutant of V. tubiashii not only produced reduced amounts of protease but also showed decreased toxicity to C. gigas larvae. Vibrio cholerae strains carrying the vtpA or vthA gene successfully secreted the heterologous protein. Culture supernatants of V. cholerae carrying vtpA but not vthA were highly toxic to Pacific oyster larvae. Together, these results suggest that the V. tubiashii extracellular metalloprotease is important in its pathogenicity to C. gigas larvae.

scholarly journals TetR-Type Transcriptional Regulator VtpR Functions as a Global Regulator in Vibrio tubiashii

2009 ◽  
Vol 75 (24) ◽  
pp. 7602-7609 ◽  
Author(s):  
Hiroaki Hasegawa ◽  
Claudia C. Häse
Keyword(s):  
Virulence Factors ◽  
Elevated Temperatures ◽  
Extracellular Proteins ◽  
Protease Production ◽  
High Homology ◽  
Global Regulator ◽  
Extracellular Proteases ◽  
Negative Effects ◽  
Vibrio Tubiashii ◽  
Protein Functions

ABSTRACT Vibrio tubiashii, a causative agent of severe shellfish larval disease, produces multiple extracellular proteins, including a metalloprotease (VtpA), as potential virulence factors. We previously reported that VtpA is toxic for Pacific oyster (Crassostrea gigas) larvae. In this study, we show that extracellular protease production by V. tubiashii was much reduced by elevated salt concentrations, as well as by elevated temperatures. In addition, V. tubiashii produced dramatically less protease in minimal salts medium supplemented with glucose or sucrose as the sole carbon source than with succinate. We identified a protein that belongs to the TetR family of transcriptional regulators, VtpR, which showed high homology with V. cholerae HapR. We conclude that VtpR activates VtpA production based on the following: (i) a VtpR-deficient V. tubiashii mutant did not produce extracellular proteases, (ii) the mutant showed reduced expression of a vtpA-lacZ fusion, and (iii) VtpR activated vtpA-lacZ in a V. cholerae heterologous background. Moreover, we show that VtpR activated the expression of an additional metalloprotease gene (vtpB). The deduced VtpB sequence showed high homology with a metalloprotease, VhpA, from V. harveyi. Furthermore, the vtpR mutant strain produced reduced levels of extracellular hemolysin, which is attributed to the lower expression of the V. tubiashii hemolysin genes (vthAB). The VtpR-deficient mutant also had negative effects on bacterial motility and did not demonstrate toxicity to oyster larvae. Together, these findings establish that the V. tubiashii VtpR protein functions as a global regulator controlling an array of potential virulence factors.

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