Modulation of Immune Response in Edible Fish against Aeromonas hydrophila

The present study was to obtain a basic knowledge of the hematology of Catla catla Post challenged with Aeromonas hydrophila. Fish were fed diets representing different supplementation levels of Aegle marmelos fruit extract. The various concentration of fruit extract were 10mg, 20mg and 30mg per 100g for each diet of fi sh. Supplementation of experimental feed after seven days collected from serum in treated fi sh to haematological parameters and biochemical parameters were analysed between control and experiment. The results of challenge test suggest that the fi shes fed with 30mg Aegle marmelos diet had better immunostimulatory activity compared to the control group. Thus, our fi nding confi rms our concentration that Aegle marmelos is a growth promoter and immunostimulant. Research Article Modulation of Immune Response in Edible Fish against Aeromonas hydrophila R Muthu*, Rajan MK and S Rajeshwari Department of Zoology, Ayya Nadar Janaki Ammal College (Autonomous), Sivakasi, India Received: 09 January, 2018 Accepted: 17 January, 2018 Published: 18 January, 2018 *Corresponding author: R Muthu, Department of Zoology, Ayya Nadar Janaki Ammal College (Autonomous), Sivakasi, India, E-mail:


Introduction
Aquaculture is one of the important sectors contributing signifi cantly in the Indian economy. Fish culturists are encouraged towards intensifi cation of culture system to increase production and profi t. In such practice of fi sh and shrimp farming, disease becomes major threats. Disease is one of the most important constraints of fi sh production both in culture system, as well as in wild condition [1]. For the last twenty years, the problem of microbial diseases has emerged as a major constraint to aquaculture industry. Increased disease occurrences have resulted due to the transfer of pathogenic organisms among cultured species of fi sh and shrimp, between different countries without proper quarantine measures. Due to this, the fi sh industry in India as well as other Southeast Asian countries has suffered signifi cant economic losses [2].
Fish production is decreased due to the occurrence of disease caused by different pathogens in aquaculture. Aquaculture has been a tradition in several parts of Asia and according to FAO statistics, over 80% 0f fi sh produced by aquaculture come from Asia, where the production was 31.07 million metric tons valued at $ 38.855 billion [4]. Aeromonas hydrophila is a gram negative motile bacterium. The ulcerative disease is mostly caused by gram negative bacterium. Aeromonas hydrophila is pathogenic not only to fi shes but also to amphibian, reptiles and mammals including man [5]. Aeromonas sp. is a ubiquitous inhabitant of aquatic ecosystems such as, freshwater, coastal water and sewage. These bacteria are usually microbiota as well as primary or secondary pathogens of fi sh and amphibians. Some motile species of Aeromonas, such as, Aeromonas caviae, A.hydrophila and A.veronii are opportunistic pathogens of humans. Among the species belonging to Aeromonas genus, one of the most important is A. salmonicida, a fi sh pathogen which causes a common disease among salmonids, named furunculosis or ulcerative furunculosis [6]. The Indian major carps, Catla catla, Labeo rohita and Cirrhinus mrigala are the most important commercial fi shes in India with a maximum market demand and acceptability as food by the consumers due to their taste and fl esh. They contribute about 67% of total freshwater fi sh production [7]. Catla catla and Labeo rohita contribute a major portion to the freshwater fi sh production in South India. The Indian major carp Catla catla mainly inhabits in rivers. It can also be easily cultured in ponds and lakes Catla is nonpredatory and its feeding is restricted of the Catla enables its safe introduction into fi sh community including Rohu, Mrigal, etc. despite its reputations as a vegetarian species [8]. Aegle marmelos, a plant indigenous to India has been used by the inhabitants of the Indian subcontinent for over 5000 years. The leaves, bark, roots, fruits and seeds are used extensively in the Indian traditional system of medicine the Ayurveda and in various folk medicine to treat myriad ailments. Bael fruits are of dietary use and the fruit pulp is used to prepare delicacies like murabba, puddings and juice. Bael fruits are also used in the treatment of chronic diarrhea, dysentery, and peptic ulcers, as a laxative and to recuperate from respiratory affections in various folk medicines [9]. Hence, the present study has been carried out the Haematological studies on disease induced Indian major carp; Catla catla (L) fed with Aegle marmelos formulated diet.

Materials and Methods
Alive and activity fi shes (12± 1g) were collected from Hightech fi sh farm, Madurai, Tamil Nadu, India. The fi shes were maintained in non-chlorinated at 20 day. The ground nut oil cake, fi sh meal and rice bran, tapioca, soybean, were mixed and sterilized. And then add a multivitamin tablet. The above mixed foods were added with different concentrations (1.0g, 1.5g and 2.0g) of plant extract prepared using shoxlet apparatus. These extract Melia azedarach extract used for experimental fi shes and without plant extract diet for control fi sh. The food was made into small pellets. 0.1 ml of 10 CFU/ ml of Aeromonas hydrophila was injected intraperitoneally both for control and experimental. In every seven days following physiological studies such as

Survival and mortality
The survival and mortality rate was calculated by dividing the number of fi sh died to the total number of fi sh.

Number of fish died
Survival rate 100 Total number of fish  

Erythrocyte count
Erythrocytes were counted by the method of Rusia and Sood [10] using haemocytometer. at a concentration of 0.2mg/ml was prepared. One ml of the standard solution was taken in a test tube. 10 mg of muscles was isolated and homogenized with a mortar and pestle by adding 5 ml of 10% TCA and certifuged at 3000 rpm for 15 minutes. Then the precipitate was dissolved in 1 ml of 0.1N NaOH solution taken in the test tube. A blank was also prepared with 1 ml of distilled water.
To the test tube, 5.5 ml of reagent (50 ml of reagent A + 1 ml of reagent B) Reagent A-2% sodium carbonate in .1N NaOH reagent B-0.5% copper sulphate in solution in 1 % sodium potassium tartarate (freshly prepared).
After 15 minutes 0.5 ml of folin -cicolteau reagent was added. Blue color was developed and optical density was measured in photoelectric colorimeter at red fi lter after 20 minutes. The amount of protein in 10 mg of tissue was calculated by using the formula.

Results and Discussion
In this study the cumulative percentage of Mortality, RBCs, and WBCs, were studied in disease induced Catla catla using different concentration of Aegle marmelos formulated died against Aeromonas hydrophila. In control groups showed 60% mortality 10g of died fed groups was 20% mortality and 30g of fed diet no mortality in experimental groups. Similar result were observed by [11], reported that Mikania cordata leaf powder signifi cantly increased non-specifi c immunity and decreased mortality in C. catla experimentally infected with Aphanomyces invadans. The M. cordata leaf powder supplemented diet showed signifi cantly (p<0.05) high disease resistance against A.
reported that the experimental groups of C. carpio administered with different dose of Cannon-ball tree, Couroupita guianensis plant extract treated fi shes showed no mortality and 100% survival. This is due to the immunostimulant potential of plant extract. Also [13], reported that A. hydrophila (10 6 CFU/ml) injected fi shes showed 89.47 % mortality and severe lesions and wound were noticed in the infected portions. The injured tails appeared reddish in colour and loss of skin layer was observed.
The RBCs count was increased with increasing concentration of plant extract formulated diet in different day of treatment [7,14,21,28,35]. Similarly result are also observed by the [14], reported that WBC and RBC counts were higher in Labeo rohita fi ngerlings fed Mangifera indica kernel when compared to control [15], reported that fi sh fed with herbs had signifi cantly higher WBC and RBC counts compared to the control. [16], reported that mixed herbal extract supplementation diets the altered haematological parameters and triggered the innate In agreement with the fi nding, reported that WBC and RBC counts were higher in Labeo rohita fi ngerlings fed Magnifera