Outbreaks of mass mortality among cultured juvenile Chinese shrimp Fenneropenaeus chinensis occurred during summer 2010 in Jiangsu Province, PR China. Gross signs of disease included lethargy, swimming near the water surface and close to pond edges, pale red shell and appendages, breaking of antenna, and reduction in food consumption. Green and yellow bacterial colonies were recovered on thiosulfate citrate bile salt sucrose agar plates from the diseased shrimp. The predominant observed colonies were purified (VP1 and VR1) and their virulence toward postlarvae of Fenneropenaeus chinensis confirmed by bath experimental challenges. The phenotypic characteristics of the isolates, including morphological, physiological, and biochemical traits, were determined. Three housekeeping genes (16S rRNA, RNA polymerase a-chain (rpoA), and DNA gyrase B subunit (gyrB)) were sequenced, and phylogenetic trees based on rpoA and gyrB sequences were constructed. Phenotypic and genetic results confirmed the diseased shrimp were infected with both Vibrio parahaemolyticus and Vibrio rotiferianus. To our knowledge, this is the first report of V. rotiferianus as a pathogenic bacteria in shrimp. In addition, the activities of extracellular enzymes and hemolysin were also studied. Results showed that all the isolates (VP1–VP3 and VR1–VR3) produced β-hemolysis on rabbit blood agar, lecithinase, proteinase, and gelatinase, but DNase and lipase were not produced.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 33 • No. 1