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The ridge-tail white prawn, Exopalaemon carinicauda, is an important economic shrimp in the mariculture of China, especially in Jiangsu Province. The “zombie disease” of ridge-tail prawn is a new epidemic that is a highly transmissible and pathogenic fungal disease caused by Metschnikowia bicuspidateinfection. To understand the response mechanism of E. carinicaudaafter M. bicuspidateinfection, the hepatopancreas of shrimp injected with M. bicuspidateMQ2101 and normal saline solution were used for proteomics analysis. A total of 5078 proteins were identified, of which 1708 proteins were identified as differentially expressed proteins (DEPs, 1311 upregulated and 397 downregulated) using a 1.2-fold change in expression as a physiologically significant benchmark. These DEPs were mainly involved in cellular processes, single-organism processes, and metabolic processes in the GO enrichment analysis and metabolism, translation, signal transduction, cell growth and death, and immune system pathways in the KEGG enrichment analysis. The DEPs related to immunity and metabolism were significantly changed, such as CTSB, CPs, DSP1, GDP, and ADH3, and these proteins might be potential determinants of E. carinicaudaresponses to M. bicuspidatainfection. qRTPCR was used to detect changes in the expression of nine DEP-related genes at the transcriptional level to validate the proteomics analysis results, and the results of the transcription tendencies in qRTPCR were consistent with proteomics analysis. The results of this study might provide an important theoretical basis for the response mechanism of ridge-tail white prawns to M. bicuspidateinfection and scientific prevention and control of this fungus in ridge-tail white prawn aquaculture.

Increasing evidences have showed that a tight link among pathogen infection, physiological indicators and intestinal microbiota. To investigate effects of Enterocytozoon hepatopenaei(EHP) infection to growth retardation and intestinal microbiota, different sized Pacific white shrimp (Penaeus vannamei) infecting with EHP were studied. The shrimp with big, medium and small sized groups were from same batch of postlarvae and reared in one pond under the same diet and environmental conditions. Number of EHP copies revealed that the more EHP copies the smaller size of shrimp individuals. Denaturing gradient gel electrophoresis (DGGE) profiles showed intestinal bacterial patterns of small sized shrimp were similar to the middle sized shrimp, rather than the big sized shrimp. It implied that intestinal microbiota were influenced by severity of EHP infection and suggested the different sizes of shrimp were due to the successive infection period of EHP. Among the different sized groups, the relative abundance of Vibrioof small group was the highest, suggesting EHP infection could result in higher susceptibility to pathogen invasion. Our findings provided the evidence intestinal bacterial patterns altered by infection of EHP, the more EHP copies the smaller size of shrimp, and different sized individuals due to successive infection period of EHP.