scholarly journals The Role of Nile Tilapia (Oreochromis niloticus) in the Life Cycle of Toxocara spp.

2021 ◽  
Vol 8 ◽  
Author(s):  
Everton André de Oliveira ◽  
Yslla Fernanda Fitz Balo Merigueti ◽  
Isabella Braghin Ferreira ◽  
Isabele Santos Garcia ◽  
Alini Soriano Pereira ◽  
...  

The present study aimed to experimentally assess Nile tilapia as potential paratenic host of Toxocara spp. A total of 15 Nile tilapia (Oreochromis niloticus) were fed with 300 embryonated Toxocara canis eggs by oral gavage, while five others of the control group received distilled water. The fish were individually analyzed at 16, 24, 48, 72, and 240 h after inoculation. Water contamination was assessed, and tissue migration by liver, gastrointestinal tract (GIT), eyes, and central nervous system. A murine model was used as the paratenic host for egg infectivity assessment. Eggs and larvae were found in plastic tank water and fish GIT, ranging from 23 to 86% per fish. Eggs and larvae were recovered from the tank water (76.3%) and fish GIT (23.7%). The counting of eggs and larvae observed was negatively correlated with number of eggs and larvae in the water tank (rho = −0.698, p = 0.003). Shedding of embryonated eggs was first detected at 16 and up to 240 h, with significant egg and larvae yield decrease on water-shedding (p = 0.001) and in the GIT (p = 0.007). Although no T. canis larva was recovered in fish tissues, egg infectivity after fish GIT transit was experimentally confirmed by mice assessment. In conclusion, despite shedding viable embryonated eggs through the gastrointestinal tract, tilapias may not play a role as a suitable paratenic hosts for Toxocara spp., posing low risk of zoonotic transmission by fish meat consumption.

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Mosleh M. Abomughaid

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.


2020 ◽  
Vol 21 (3) ◽  
pp. 53-60
Author(s):  
Enas Hassan ◽  
Gehad El-Sayed ◽  
Azza Hassan ◽  
Shaimaa Abd Elsalam

Objective: This study was conducted to evaluate the influence of pollution with lead, copper, cadmium on the gene expression pattern of liver Glutathione-S-transferase and serum lysozyme in Nile tilapia (Oreochromis. niloticus). Design: Descriptive study. Fish: A Total of 120 Nile tilapia fish (Oreochromis niloticus) samples were collected from Lake Manzala, and drainage water at different localities. Procedures: Cd, Cu, and Pb concentrations residues within mid-dorsal muscle tissue, within gills, liver, and kidney were determined. Erythrocyte count, hemoglobin concentration, Packed Cell volume and other blood indices, as well as, total leukocyte count were measured. Biochemically, Alanine transaminase, Aspartate transaminase activities, total protein, creatinine, uric acid, lysozymes activity were estimated. GST gene expression was determined in the liver. Results: The results showed that Pb, Cu and Cd were bio accumulated at a higher level in the liver, kidney and gills of Nile tilapia fish (Oreochromis niloticus) from all sampling sites. The levels of the ALT and AST were increased, total protein and Albumin concentrations were decreased. Creatinine and uric acid were significantly (P≤ 0.05) increased in all groups (compared to the control group. Hematological parameters and lysozyme activity were decreased. Up regulation of the hepatic GST expression levels in Nile tilapia exposed to the heavy metals in comparison to the control value. Conclusion and clinical relevance: This study shows that lead, copper and cadmium were bio accumulated at higher concentration in liver, kidney, gills and muscles of Nile tilapia due to large industrial activities near locations of the sampling sites. Additionally, GST gene expression represents sensitive biomarker of aquatic pollution.


2020 ◽  
Vol 41 (1) ◽  
pp. 351
Author(s):  
Gláucia Frasnelli Mian ◽  
Charles Oswaldo Roncancio ◽  
Maria Cristina de Souza Silva ◽  
Amanda Carvalho Rosado Ferreira ◽  
Dircéia Aparecida da Costa Custódio ◽  
...  

Nile tilapia (Oreochromis niloticus) has always been considered more resistant to diseases compared to other fish species. However, in recent decades, this fish species has also been susceptible to many bacterial, fungal, parasitic, and nutritional diseases. In Brazil, streptococcosis is one of the main diseases that affect tilapia and has caused many economic losses. A resistance test was conducted with 93 tilapia of four varieties (UFLA strain and three commercial varieties: SC1, SC2, and SC3) to evaluate resistance to experimental inoculation with Streptococcus agalactiae. Each variety was distributed in five aquariums, with nine specimens of the same variety. Among the five aquariums, four housed fish were intraperitoneally inoculated with 107 CFU/fish of S. agalactiae and one aquarium harbored fish from the control group, which received 0.1 mL of sterile BHI (Brain Heart Infusion). Significant differences were observed in the survival rates accumulated at the end of the experiment (day 15), with values of 22, 36, 36, and 15% for SC1, SC2, SC3, and UFLA, respectively. The UFLA strain presented lower survival than other strains, which did not differ among the 15 days of challenge. These results demonstrate that there are animals with a better response to the resistance test than others.


2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4237
Author(s):  
Nadia Cristine Weinert ◽  
Julieta Volpato ◽  
Ádson Costa ◽  
Rozyanne Rosa Antunes ◽  
Aldo Camargo de Oliveira ◽  
...  

<p>Clinical hematology facilitates the diagnosis of disease and can act as a prognostic indicator of pathological conditions in fish. The aim of the present study was to evaluate hematological parameters of Nile tilapia (<em>Oreochromis niloticus</em>) subjected to different anesthetics and anticoagulants. Thirty apparently healthy fishes (average weight of 473 ± 35. 50 g and mean total length of 29. 33 ± 0. 37 cm), were selected from the local commercial fish farm in the Lages municipality (Santa Catarina, Brazil). The animals were randomly divided into three groups of 10. In two groups, anesthesia was induced with eugenol (70 mg·L- 1) (EG) and Benzocaine hydrochloride (100 mg·L-1) (BG), respectively. Anesthesia was not administered to fish of the third group (CG/control group). Blood samples were obtained by venipuncture of the caudal vessels and placed into microtubes containing sodium heparin or Na2EDTA for further analysis. The results were analyzed by Sigma Stat for Windows, the paired t-test for significant differences between anticoagulants of the same group, and analysis of variance followed by the Tukey test for comparison of means between groups (p ? 0. 05). Most of the observed changes in the erythrogram were significantly higher for the anticoagulant heparin and benzocaine group in comparison to the control group. However, the values obtained for the leukogram were significantly higher for all groups subjected to the Na2EDTA anticoagulant, suggesting that heparin may cause cell clumping. The results suggest that the anesthetics under investigation effectively minimizes the effects of stress caused by handling and invasive procedures, and that the anticoagulant heparin causes less hemolysis in comparison to Na2EDTA for Nile tilapia. Thus, the hematological variations attributed to different anesthetic protocols and/or different anticoagulants should be considered for the species <em>Oreochromis niloticus. </em></p>


2016 ◽  
Vol 91 (5) ◽  
pp. 633-636 ◽  
Author(s):  
M. Zibaei ◽  
S.M. Sadjjadi ◽  
S. Maraghi

AbstractConsuming raw and undercooked meat is known to enhance the risk of human toxocariasis because Toxocara species have a wide range of paratenic hosts, including chickens. The aim of this study was to identify species of Toxocara in naturally infected broiler chickens using molecular approaches. A polymerase chain reaction (PCR) method was used for the differentiation of Toxocara canis and Toxocara cati larvae recovered from tissues and organs, and identified by microscopic observations. Thirty-three 35- to 47-day-old broiler chickens were used for examination of Toxocara larvae. The duodenum, liver, lungs, heart, kidneys, skeletal muscles and brain of each chicken were examined using the pepsin method, and DNA from each tissue was extracted as the template for PCR assay. The findings revealed that 5 of 33 (15.2%) broiler chickens were infected with Toxocara larvae. Larvae were recovered from the liver (n = 19), duodenum (n = 8), skeletal muscles (n = 8) and brain (n = 2) of broiler chickens naturally infected with Toxocara spp. The results showed that the frequencies of the species in the chickens were T. canis larvae (n = 5, 83.3%) and T. cati larvae (n = 1, 16.7%). Our data from the present study demonstrated the importance of broiler chickens as a paratenic host for the parasite's life cycle in the environment. The implementation of DNA amplification as a routine diagnostic technique is a specific and alternative method for identification of Toxocara larvae, and allowed the observation of specific species under field conditions within the locations where broiler chickens are typically raised and exposed to Toxocara spp. eggs or larvae.


Author(s):  
A. Jemimah ◽  
Y. M. Yahaya ◽  
T. Murna ◽  
A. Rejoice ◽  
A. Bara’atu

Aim: The aim of the study is to identify helminth parasites in the gastrointestinal tract of Oreochromis niloticus in Dadin Kowa Dam, Yamaltu Deba Local Government Area, Gombe State. Study design:  Oreochromis niloticus fish species were randomly obtained from the local fishermen in the landing sites; between 7:00am-10:00am weekly. Place and duration of study: The study was carried out at Dadin Kowa Dam in Yamaltu Deba Local Government Area of Gombe State between the months of March to June, 2019. Methodology: 60 Oreochromis niloticus (Nile Tilapia) were obtained and examined for gastro intestinal parasites. Sex of the fish was determined by the presence and absent of an intromittent organ. The total length, standard length and body weight was measured using standard method. Dissection was done using standard procedure and the Parasites recovered were identified using the helminth parasites of fish identification guide. Results: Out of the 60 fish species examined. (23 female and 37 males), 21 (35.00%) were infected and were observed to habour six (6) endoparasites; viz nematodes, Cestodes and trematodes. The results show that there was a significant difference between infection rate, total length and weight of fish with female species having relatively higher percentage prevalence 11(43.50%) than the males 10 (29.70%). It was observed that the prevalence of parasitic infection increase with length and weight of the fish. Conclusion: Presence of these fish helminth parasites may lead to devaluation in protein constant in the body of the fish. The work therefore recommends water quality assessment of Dams as it is one of the factors that bring about the increase in parasitic infection.


Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1309
Author(s):  
Luís Félix ◽  
Rita Correia ◽  
Rita Sequeira ◽  
Cristiana Ribeiro ◽  
Sandra Monteiro ◽  
...  

The use of anesthetics has been suggested as a strategy to hamper live fish transport-induced stress. Still, there is insufficient data available on the use of alternative anesthetics to MS-222. This study investigated the use of propofol to mitigate stress in Nile tilapia (Oreochromis niloticus, 143.8 ± 20.9 g and 20.4 ± 0.9 cm) during a 6 h simulated transport. Individuals (n = 7) were divided into three groups: control, 40 mg L−1 MS-222, and 0.8 mg L−1 propofol. A naïve group non-transported was also considered. During the 6 h transport and 24 h after, the response to external stimuli, opercular movements, water quality parameters, behavior, blood hematology and other physiological values, the histopathology of the gills, the quality of the fillet, and oxidative-stress changes in gills, muscle, brain, and liver were evaluated. Propofol increased swimming activity of fish but decreased opercular movements and responses to external stimuli, indicating oscillations of the sedation depth. Water pH and glucose levels increased, while hematocrit (HCT) and lactate decreased in propofol groups at 6 h. At this time-point, MS-222 also induced a decrease in the HCT and lactate levels while increasing cortisol levels. Despite these effects, the stress-related behaviors lessened with anesthetics compared to the control group. After the recovery period, physiological responses normalized in animals from both anesthetic groups, but the control still had high cortisol levels. Overall, propofol is a good alternative for the transportation of this species, showing efficient sedation without compromising health or fillet quality. However, further pharmacodynamics and pharmacokinetics knowledge is required to support its use in aquaculture settings.


2022 ◽  
Vol 10 (1) ◽  
pp. 177
Author(s):  
Patrick Waindok ◽  
Elisabeth Janecek-Erfurth ◽  
Dimitri L. Lindenwald ◽  
Esther Wilk ◽  
Klaus Schughart ◽  
...  

Toxocara canis and Toxocara cati are globally occurring zoonotic roundworms of dogs and cats. Migration and persistence of Toxocara larvae in the central nervous system of paratenic hosts including humans may cause clinical signs of neurotoxocarosis (NT). As pathomechanisms of NT and host responses against Toxocara larvae are mostly unknown, whole-genome microarray transcription analysis was performed in cerebra and cerebella of experimentally infected C57Bl/6J mice as paratenic host model at days 14, 28, 70, 98, and 120 post-infection. Neuroinvasion of T. cati evoked 220 cerebral and 215 cerebellar differentially transcribed genes (DTGs), but no particular PANTHER (Protein ANalysis THrough Evolutionary Relationships) pathway was affected. In T. canis-infected mice, 1039 cerebral and 2073 cerebellar DTGs were identified. Statistically significant dysregulations occurred in various pathways, including cholesterol biosynthesis, apoptosis signaling, and the Slit/Robo mediated axon guidance as well as different pathways associated with the immune and defense response. Observed dysregulations of the cholesterol biosynthesis, as well as the Alzheimer disease-amyloid secretase pathway in conjunction with previous histopathological neurodegenerative findings, may promote the discussion of T. canis as a causative agent for dementia and/or Alzheimer’s disease. Furthermore, results contribute to a deeper understanding of the largely unknown pathogenesis and host-parasite interactions during NT, and may provide the basis for prospective investigations evaluating pathogenic mechanisms or designing novel diagnostic and therapeutic approaches.


2021 ◽  
Vol 16 (2) ◽  
pp. 109
Author(s):  
Ratchaneegorn Mapanao ◽  
Wirat Jiwyam ◽  
Wilailuk Khrueanet ◽  
Nudtha Nithikulworawong

Herbal medicine, including moringa (Moringa oleifera), is widely used as dietary supplementation to enhance growth performance and increase disease resistance in aquaculture. This study aimed to investigate the effects of supplementing moringa leaves on growth performance, hematology and disease resistance of nile tilapia (Oreochromis niloticus) against Aeromonas hydrophila. Fish (38.05 ± 0.83 g) were fed with a commercial feed supplemented by moringa leaves at 0%, 15%, 20%, and 25%, ad libitum, twice a day for eight weeks. Results revealed that 15% moringa leaves supplemented diet gave the highest weight gain, while the specific growth rate was statistically significantly different (p<0.05) among the treatments. Fish fed with 25% supplementation had the highest total red blood cell count and total white blood cell count. All experimental groups had higher values of red blood cells and white blood cells than the control group. The challenge test with A. hydrophila showed that the fish fed with the 25% moringa leaves supplementation diet had the highest relative percentage survival rate. There were no significant differences among the treatment groups. However, the treatment groups had a statistically significant difference with the control group (p<0.05). Results of the present study indicated that supplementation of 15% moringa leaves in diet gave optimal growth performance, while supplementation of 25% moringa leaves in the diet showed the best results in terms of the health of nile tilapia. Moringa leaves supplemented in nile tilapia diet enhanced growth performance and increased disease resistance against A. hydrophila.


2017 ◽  
Vol 45 (1) ◽  
pp. 1-10
Author(s):  
Sumaiya Ahmed ◽  
Bernd Giese ◽  
Volker Schulz ◽  
Md Sagir Ahmed

The effects of toxic Microcystis aeruginosa on the liver of Nile tilapia, Oreochromis niloticus were investigated in the laboratory. Four treatments were setup into aquariums for 15 days to investigate the histopathological changes exposed to Microcystis aeruginosa bloom. Fishes of treatment A1 were treated as a control group and given artificial feed. In the three treatments (A2, A3 and A4), the M. aeruginosa cell concentration were 35 × 102, 72 × 102, 149 × 102 colony/ml, respectively. In the control group, no histopathological change was observed. In exposed fish, histopathological alterations were characterized by swollen and granular cytoplasm, vascular proliferation, bile stasis, fatty change and focal necrosis. Histopathological changes were observed within five days of exposure when fish exposed to moderate (72 × 102 colony/ml) to high (149 × 102 colony/ml) bloom concentration, whereas it took 15 days in lower concentration (35 × 102 colony/ml). Histopathological changes proved that intake of toxic M. aeruginosa bloom by aquatic animals, particularly Nile tilapia has significant effects on its internal organs that may cause of massive mortality. Accordingly, cyanotoxin accumulation in fish tissue my pose a risk to human health through the food chain.Bangladesh J. Zool. 45(1): 1-10, 2017


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