A contribution on motile aeromonas septicemia caused by Aeromonas sobria in common carp (cyprinus carpio)‎ with trials for disease prevention

الملخص EN

Along one year, clinically diseased cultured common carp showing hemorrhages on different parts of the body surface and fins, fin and tail rot with septicemic lesions in internalorgans were exposed to bacteriological examination.

On the basis of biochemical characteristics and API 20 E system, the bacteria were identified as Aeromonas sobria, A.

jandaei and A.

veronii.

70 % of examined fish were affected with motile aeromonas species.

A.

sobria was the most prevalent bacteria 98 % among other isolated motile aeromonas species and was recorded in all seasons except winter.

All examined isolates of A.

sobria (9) were highly pathogenic to carp at 0.2 ml of 108 cells / ml.

PCR indicated that 6 isolates of A.

sobria showed the aerolysine gene at 462 base pare and not detected in A.

jandaei or A.

veronii.

Trials for disease prevention by feeding on live yeast and vaccination were done.

The using of live yeast Saccaromycis castelli at 5 g per Kg commercial diet increased fish resistance against A.

sobria infection through decreasing the mortality from 100 % to 10 % and increasing respiratory burst and serum lysozyme activities compared to control.

Also, vaccination with Formalin Killed vaccine of A.

sobria by injection and oral routes gave protection against experimental infection by A.

sobria than control.

Antibody titre was higher in vaccinated group by injection than orally vaccinated group.

Live yeast and vaccine increased carp resistance against A.

sobria.