scholarly journals Isolation and Identification of Some Probiotic Bacteria and Their Potential Role in Improving Immune Response and Resistance of Nile Tilapia (Oreochromis niloticus) in Comparison with a Commercial Product

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Mosleh M. Abomughaid
Keyword(s):  
Immune Response ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Management Tool ◽  
Phagocytic Index ◽  
Control Group ◽  
Second Phase ◽  
Feeding Experiment ◽  
Isolation And Identification

This work aimed to retrieve a field isolate of probiotic from Nile tilapia (Oreochromis niloticus) and compare the obtained results with a commercial probiotic product through experimental studies. The study was conducted on 250 Nile tilapia. Ten fish were used to isolate the probiotic strain. Two isolates showed an in vitro inhibitory effect against pathogenic A. hydrophila. The isolate with the largest zone was identified by PCR. Sixty fish were used to test the safety of a potential probiotic. One hundred and eighty fish were used in a two-month feeding experiment. Fish were divided into 3 groups, group (1): the control, group (2): fed on potential probiotics, and group (3): fed on commercial probiotic (Organic Green™). The effects of tested products on the immune response were recorded in all groups. After one and two months of feeding experiment, blood and nonspecific immune parameters were evaluated. Disease resistance against Aeromonas hydrophila was evaluated through challenge experiment. The histopathology of the treated groups was fully recorded in comparison with the control group. The potential probiotic based on the in vitro antimicrobial activity test was identified as P. putida using routine and gel electrophoresis and 16S rRNA sequencing. During the first and the second month of experiment, there was a highly significant increase in the survival percent of the experimental fish in both treated groups with probiotics. In the first phase of the experiment, a significant increase in the haematocrit values and NBT, lysozyme activity, and phagocytic activity was seen in all treated groups in comparison with the control. The increase in the TLC was significant in the group fed with P. putida in comparison with the control group. In the second phase, a nonsignificant increase in the hematocrit values and significant increases in the NBT and phagocytic index were seen in P. putida and organic green groups in comparison with the control group. The TLC and DLC revealed nonsignificant changes in the treated groups in comparison with the control. The RLP in the groups treated with P. putida was higher than that in those treated with organic green. Although probiotics are an important management tool in aquaculture, it should be subjected to scientific laboratory tests and field measurements.

scholarly journals LECT2 Protects Nile Tilapia (Oreochromis niloticus) Against Streptococcus agalatiae Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Qi Li ◽  
Zhiqiang Zhang ◽  
Weiqi Fan ◽  
Yongxiong Huang ◽  
Jinzhong Niu ◽  
...  
Keyword(s):  
Immune Response ◽  
Bacterial Infection ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Head Kidney ◽  
Transcriptional Level ◽  
Reading Frame ◽  
Tissue Damages

Leukocyte cell-derived chemotaxin 2 (LECT2) is a multifunctional cytokine that especially plays an important role in innate immune. However, the roles of LECT2 in the immune response of the economically important fish Nile tilapia (Oreochromis niloticus) against bacterial infection remains unclear. In this study, a lect2 gene from Nile tilapia (On-lect2) was identified, and its roles in the fish’s immune response against bacterial infection were determined and characterised. On-lect2 contains an open reading frame of 456 bp that encodes a peptide of 151 amino acids, as well as the conservative peptidase M23 domain. On-LECT2 is 62%–84% identical to other fish species and about 50% identical to mammals. The highest transcriptional level of On-lect2 was detected in the liver, whereas the lowest levels were detected in the other tissues. Moreover, the On-LECT2 protein is located mainly in the brain and head kidney. The transcriptional levels of On-lect2 substantially increased in the head kidney, brain, liver and spleen after Streptococcus agalactiae infection. Knockdown On-lect2 led to higher mortality due to liver necrosis or haemorrhage and splenomegaly. In vitro analysis indicated that the recombinant protein of On-LECT2 improved phagocytic activity of head kidney-derived macrophages. In vivo challenge experiments revealed several functions of On-LECT2 in the immune response of Nile tilapia against bacterial infection, including promotion of inflammation, reduction of tissue damages and improvement of survival rate.

Incidence and molecular characterization of fungi and yeast isolated from cultured catfish and Nile tilapia

2020 ◽  
Vol 21 (3) ◽  
pp. 61-66
Author(s):  
Ola Hashem ◽  
Viola Zaki ◽  
Rawia Adawy
Keyword(s):  
Molecular Characterization ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Clarias Gariepinus ◽  
Fungal Species ◽  
High Rate ◽  
Fish Farms ◽  
Isolation And Identification ◽  
Penicillium Spp

Objective: To study the incidence and seasonal dynamics of different fungi affected freshwater fishes in Lake Manzala with molecular identification of the isolated fungi. Animals: 300 Nile tilapia (Oreochromis niloticus) and 300 catfish (Clarias gariepinus). Design: Descriptive study. Procedures: Random samples of Oreochromis niloticus (O. niloticus) and Clarias gariepinus (C. gariepinus) were collected from Manzala fish farms. Clinical and postmortem examination of fish was applied. Isolation and identification of different fungi were performed by conventional methods. Furthermore, the molecular characterization of isolated fungi was carried out. Results: C. gariepinus had a higher rate of infection with different fungal species than O. niloticus. Aspergillus spp. (Aspergillus niger and Aspergillus flavus) were the most fungal isolated from the examined fishes, followed by Penicillium spp. and Candida albicans. Aspergillus spp were detected in all seasons with a higher rate in summer and spring. A. flavus, A. niger, Penicillium spp. and C.albicans isolates were amplified from both C. gariepinus and O. niloticus at the specified molecular weight using PCR. Conclusion and clinical relevance: Fungal infection affected the fish showing different external and internal lesions, all species of Aspergillus were found in all seasons with a high rate in, hot seasons, summer and spring. The Prevalence of Penicillium and C. albicans were also reported. All fungal isolates were identified on the phenotypic and molecular bases.

Generation of mouse monoclonal antibodies specific to tilapia immunoglobulin using fish immunoglobulin/BSA complex for monitoring of the immune response in Nile tilapia Oreochromis niloticus

2018 ◽  
Vol 50 (1) ◽  
pp. 277-283 ◽  
Author(s):  
Tanapon Soonthonsrima ◽  
Pradit Wangman ◽  
Parin Chaivisuthangkura ◽  
Chalinan Pengsuk ◽  
Paisarn Sithigorngul ◽  
...  
Keyword(s):  
Immune Response ◽  
Monoclonal Antibodies ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Nile Tilapia Oreochromis Niloticus

scholarly journals How Dopamine Influences Survival and Cellular Immune Response of Rhipicephalus microplus Inoculated with Metarhizium anisopliae

2021 ◽  
Vol 7 (11) ◽  
pp. 950
Author(s):  
Thaís Almeida Corrêa ◽  
Jéssica Fiorotti ◽  
Emily Mesquita ◽  
Laura Nóbrega Meirelles ◽  
Mariana Guedes Camargo ◽  
...  
Keyword(s):  
Immune Response ◽  
Metarhizium Anisopliae ◽  
Cellular Immune Response ◽  
Tick Control ◽  
Rhipicephalus Microplus ◽  
Phagocytic Index ◽  
Control Group ◽  
Immune Functions ◽  
Phenoloxidase Activity ◽  
Cellular Immune

Dopamine (DA) is a biogenic monoamine reported to modulate insect hemocytes. Although the immune functions of DA are known in insects, there is a lack of knowledge of DA’s role in the immune system of ticks. The use of Metarhizium anisopliae has been considered for tick control, driving studies on the immune response of these arthropods challenged with fungi. The present study evaluated the effect of DA on the cellular immune response and survival of Rhipicephalus microplus inoculated with M. anisopliae blastospores. Exogenous DA increased both ticks’ survival 72 h after M. anisopliae inoculation and the number of circulating hemocytes compared to the control group, 24 h after the treatment. The phagocytic index of tick hemocytes challenged with M. anisopliae did not change upon injection of exogenous DA. Phenoloxidase activity in the hemolymph of ticks injected with DA and the fungus or exclusively with DA was higher than in untreated ticks or ticks inoculated with the fungus alone, 72 h after treatment. DA was detected in the hemocytes of fungus-treated and untreated ticks. Unveiling the cellular immune response in ticks challenged with entomopathogenic fungi is important to improve strategies for the biological control of these ectoparasites.

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