Research Article: Amelioration of hemato-serological parameters, antioxidant capacity, and resistance against Aeromonas hydrophila in common carp (Cyprinus carpio) fed with quorum quenching probiotics

In this study, two probiotics (Citrobacter freundii and Bacillus foraminis) with indigenous quorum quenching (QQ) were isolated from the intestine of Cyprinus carpio and their effects on hemato-serological parameters and innate immune responses, antioxidant capacity and disease resistance in C. carpio were determined. The juveniles (n=۴۵۰, ۵۰.۲۶±۱۰.۴۷ g mean weight) were randomly divided into ۶ groups (with ۳ replications) and fed with diets containing ۱×۱۰۹ cfu g-۱ of C. freundii (QQ۱, G۱), B. foraminis (QQ۲, G۲), Lactobacillus plantarum (without characteristics QQ, WQQ, G۳), QQ۱+QQ۲ (G۴), QQ۱+QQ۲+WQQ (combine, G۵), and a control diet (without probiotic) for ۶۰ days. The hematocrit level was increased in the fish fed with QQ۱ and WQQ supplemented diets compared to the control group. At ۳۰ days, the combined probiotic treatments (QQ۱+QQ۲+WQQ) significantly increased hemoglobin and total leukocyte count compared to QQ۱ and control, though these differences were not observed at ۶۰ days. QQ۲ notably improved complement activity and lysozyme levels after ۳۰ days, while QQ۱+QQ۲ showed a higher antitrypsin activity at ۳۰ days. The myeloperoxidase levels were elevated in the combined treatments at ۶۰ days. The hepatic catalase activity was higher in QQ probiotic groups at ۳۰ days but it was decreased by ۶۰ days with significant differences noted between WQQ and other groups. The highest superoxide dismutase activity was obtained in QQ۲ at ۳۰ and ۶۰ days. The liver glutathione level was decreased in the mixed probiotic groups but it was increased in the combined group at ۶۰ days. A lower content of malondialdehyde was in QQ۱ and QQ۲ groups at ۶۰ days. The probiotic-treated groups showed significantly lower mortality rates compared to the control against A. hydrophila infection, with the highest mortality occurring ۳۰ hours post-infection [G۱ (۳۰.۶%), G۲ (۳۰.۶%), G۳ (۴۰.۶۳%), G۴ (۳۰.۶%), G۵ (۴۰.۶۳%), and the control group (۶۰.۳%)]. Overall, the indigenous probiotics cause an improvement in various health parameters and could reduce mortality rates in infected fish.

کلیدواژه ها:

Carp ، Intestine bacteria ، Quorum quenching ، Immune response ، Aeromonas hydrophila