对虾病毒病病毒和细菌合并感染的病理特点和诊断价值

PATHOLOGICAL CHARACTERISTICS AND DIAGNOSTIC VALUE OF VIRUS CO-INFECTION WITH BACTERIA IN CULTURED SHRIMP

应用电镜超薄切片及光学石蜡切片和环氧树脂薄片技术，观察健康对照组、疾病始发组和濒临死亡组的草虾、中国对虾、日本对虾和长毛对虾的肝胰腺和中肠，结果在３组４种对虾中均检测到病毒，只在濒临死亡组的４种对虾中发现病毒与细菌的合并感染。合并感染的病毒有ＭＢＶ、球形病毒和淋巴样细胞核型杆状病毒。细菌以弧菌为主，其病理变化表现为器官和组织的保护层受损、溶解样坏死和凝固样坏死。仅以病毒和细菌合并感染作为养殖对虾病毒病早期诊断的指标是不够的，仅可作为辅助性诊断指标。但合并感染对评估对虾病毒病的预后以指导捕捞，却有一定意义。

With the techniques of electronmicroscopy and regular thin paraffin sections under light micro scope,we studied the structure of hepatopancreatic and midgut cells from three groups of shrimp(normal、just diseased and dying shrimps)each included Penaeus monodon,P.japonicus,P.chinensis and P.penicillatus species.The results showed that viruses be detected in three groups of every species,though co-infection of viruses and bacteria couled be found only in the dying group of four shrimp species.The virus types in co-infected shrimps are monodon baculovirus(MBV),spherical virus.and lymphoid cell muclear baculovirus(LNBV);the bacteria are mainly vibrios.The pathological changes of co-infection are damage and dissolution or coagulating necrosis of organs and tissues.Although detection of virus co-infection with bacteria is not enough for early diagnosis of cultured shrimp disease,it is still a valuable auxiliary index for this purpose and it might also be a useful index to evaluate the prognosis of shrimp disease and to guide harvest.