This study presents the first report of myonecrosis and hepatopancreatic necrosis in broodstock of Litopenaeus vannamei. Of the 400 individuals examined, 34 displayed myonecrosis and hepatopancreatic necrosis, conditions previously reported to be caused by bacterial, fungal, parasite, and viral infections. Gross signs of infection include passive swimming, anorexic and the abdominal muscle become opaque with extensive whitish discoloration of distal abdominal segments and the posterior appendages. Macroscopic necropsy examination revealed atrophied hepatopancreas and empty stomach and mid-gut. The histopathological investigations revealed that reddened muscular lesions are composed of coagulative and liquefactive necrosis of striated muscle fibers, often with edema. The hepatopancreas showed necrotic lesions displaying disorganized lumen and dispersed tubular epithelial cells scattered on necrotic myoepithelial cells. Gill lamellae in infected shrimp showed disorganized, necrotic filaments infiltrated with inflammatory hemocyte. The RT-PCR analysis using OIE-recommended primer and additional sets of primers used in previous studies revealed the absence of IMNV as well as other emerging pathogens including MrNV, PvNV, WSSV, IHHNV, TSV, YHV, AHPND, and EHP. Basis on these negative results, microbiological tests were performed. A dominant yellow-colored bacterial colony was isolated on TCBS agar and identified as Photobacterium damselae subsp. damselae KPD. Injection of the isolate of P. damselae KPD proved to be pathogenic to L. vannamei. The study concludes that P. damselae KPD is the causative agent of myonecrosis and hepatopancreatic necrosis and represents a threat to the Indian shrimp hatcheries.

本研究首次报道了凡纳滨对虾亲虾的肌肉坏死和肝胰腺坏死。在接受检查的400名个体中，有34名表现出了肌肉坏死和肝胰腺坏死，以前据报道是由细菌，真菌，寄生虫和病毒感染引起的。感染的大体征包括被动游泳，厌食症和腹肌变得不透明，远端腹部和后肢广泛发白。宏观尸检显示萎缩的肝胰腺，空腹和中肠。组织病理学调查显示，发红的肌肉病变由横纹肌纤维的凝固性和液化性坏死组成，常伴有水肿。肝胰脏显示坏死性病变，显示管腔紊乱，散布在坏死的肌上皮细胞上的管状小管上皮细胞。感染虾中的ill片显示出杂乱的坏死丝，浸润了炎性血细胞。使用OIE推荐的引物和先前研究中使用的其他引物进行的RT-PCR分析显示，不存在IMNV以及其他新兴病原体，包括MrNV，PvNV，WSSV，IHHNV，TSV，YHV，AHPND和EHP。基于这些阴性结果，进行了微生物测试。在TCBS琼脂上分离出显性的黄色细菌菌落并鉴定为 进行了微生物测试。在TCBS琼脂上分离出显性的黄色细菌菌落并鉴定为 进行了微生物测试。在TCBS琼脂上分离出显性的黄色细菌菌落并鉴定为damselae细菌亚种。丹塞拉KPD。注射P. damselae KPD的分离物被证明对南美乳杆菌致病。该研究的结论是，P。damselae KPD是肌肉坏死和肝胰腺坏死的病原体，对印度虾孵化场构成威胁。