Study on"Dixing disease"of Litopenaeus vannamei cultured in small shed
To explore the pathogenesis of Litopenaeus vannamei,a dominant strain MRY0520 was isolated from the hepatopancreas of dying diseased shrimp.Meanwhile,the strain MRY0520 was observed morphologically,identified physiologically and biochemically,and analyzed by molecular biology.The results showed that the strain MRY0520 was identified as Photobacterium damselae subsp.damselae,and the artificially infected L.vannamei could cause healthy shrimp exhibit the same symptoms as natural diseased shrimp.The results of artificial challenge showed that the LD50 of the bacteria to L.vannamei in 72 h was 2.15 x 105 CFU/g,the drug sensitivity test showed that strain MRY0520 was sensitive to neomycin(30 μg/disc),doxycycline(30 μg/disc)and other drugs.The bacteria was pathogenic to L.vannamei,and could cause obvious pathological changes in the hepatopancreas of the shrimp,even leading to death.
Litopenaeus vannameiPhotobacterium damselae subsp.damselaeIsolation and identificationDrug sensitivity test