Identification of Pathogen Responsible for White-spots Disease in Larimichthys crocea

Two strains of the suspected bacteria,H2013032002 and H2013032003,were isolated from croakers,Larimichthys crocea,in Sanduao,Fujian.An artificial infection with the isolates caused the similar white-spots disease in the fish.Subsequently,morphological and biochemical tests identified the isolated strains as Pseudomonas putida or P.fluorescent.Then,the 16S-rDNA sequence analysis showed that the bacteria had a 99.0%homologous rate with P.putida.In addition,a drug sensitivity test revealed that the two strains of pathogen were highly sensitive to norfloxacin,ciprofloxacin,oxolinic acid and kanamycin neomycin.It was,therefore,determined that P.putid was likely the culprit that caused the white-spots disease in croakers.