Insight into summer mortality syndrome in farmed Nile tilapia (Oreochromis niloticus) associated with bacterial infection.

Asely, Amel M. El; Youssuf, Hadeer; Gawad, Eman A. Abdel; Elabd, Hiam; Matter, Aya; Shaheen, Adel; Abbass, Amany

doi:10.21608/bvmj.2020.40404.1255

Cited by 8 publications

(6 citation statements)

References 21 publications

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“…Regarding the clinical and post-mortem findings in naturally diseased fish, which were recorded in this study, such as generalized haemorrhagic lesions, varying degrees of skin ulcers, inflamed and protruded vents, ascites and fin rot, they are similar to those documented by Youssuf et al (2020). Moreover, other symptoms were recorded, such as loss of appetite, skin darkness, detached scales and ascites with congestion mainly in the kidneys, liver and spleen (Abd El Latif et al, 2019).…”

Section: Discussionsupporting

confidence: 77%

“…including humans (Joseph et al, 1991;Lazado & Zilberg, 2018). A. veronii has been recorded in Egypt and worldwide as a cause of serious mortality in tilapia raised in the Nile River (Abd El Latif et al, 2019;Amal et al, 2018;Dong et al, 2015Dong et al, , 2017Eissa et al, 2015;Youssuf et al, 2020). The topmost important reason behind the danger of A. veronii is the existence of its virulence genes (Abd El Latif et al, 2019;Sun et al, 2016;M.…”

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confidence: 99%

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Aeromonas veroniidetection in Egyptian fish farms with summer tilapia mortality outbreaks and the role of formic acid in limiting its spread

Reda

El-Murr

Elhakim

et al. 2021

Aquaculture Research

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Egypt is the third tilapia producer globally and the top aquaculture producer in Africa (Ali et al., 2020). Because tilapia is a good protein source, it is considered one of the main keys to food security, particularly in highly populated countries, such as Egypt (El-Sayed, 2019). Besides, this industry is a source of income for many young people (Dickson et al., 2016;Salem & Saleh, 2006). However, since 2013, this industry has been exposed to a great challenge, which is high summer mortality in various fish farms along with the Nile Delta, leading to economic and social losses (Ali et al., 2020). Studies have reported multiple factors implicated in tilapia mortality, including infectious, fungal, bacterial and parasitic causes (

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Section: Discussionsupporting

confidence: 77%

mentioning

confidence: 99%

Aeromonas veroniidetection in Egyptian fish farms with summer tilapia mortality outbreaks and the role of formic acid in limiting its spread

Reda

El-Murr

Elhakim

et al. 2021

Aquaculture Research

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“…Several motile aeromonads, including Aeromonas sobria (Li and Cai 2011), A. jandaei (Dong et al 2017), A. hydrophila (AlYahya et al 2018), and A. veronii (El Asely et al 2020, are associated with disease problems and have caused mass mortalities in tilapia farming. Aeromonas veronii has been reported as the causative agent of motile Aeromonas septicemia (MAS), which is responsible for serious mortalities on tilapia farms in Egypt and worldwide (Dong et al 2015;Eissa et al 2015;Amal et al 2018;Abd El Latif et al 2019;El Asely et al 2020) and results in losses of up to 100% during mass mortality events (Dong et al 2017).…”

Section: Introductionmentioning

confidence: 99%

“…2018), and A. veronii (El Asely et al. 2020), are associated with disease problems and have caused mass mortalities in tilapia farming. Aeromonas veronii has been reported as the causative agent of motile Aeromonas septicemia (MAS), which is responsible for serious mortalities on tilapia farms in Egypt and worldwide (Dong et al.…”

Section: Introductionmentioning

confidence: 99%

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Expression profiles of four Nile Tilapia innate immune genes during early stages of Aeromonas veronii infection

Bakry,

Emeish,

Embark

et al. 2024

J Aqua Anim Hlth

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ObjectiveDuring Egypt's hot summer season, Aeromonas veronii infection causes catastrophic mortality on Nile Tilapia Oreochromis niloticus farms. Egypt is ranked first in aquaculture production in Africa, sixth in aquaculture production worldwide, and third in global tilapia production. This study aimed to investigate, at the molecular level, the early innate immune responses of Nile Tilapia to experimental A. veronii infection.MethodsThe relative gene expression, co‐expression clustering, and correlation of four selected immune genes were studied by quantitative real‐time polymerase chain reaction in four organs (spleen, liver, gills, and intestine) for up to 72 h after a waterborne A. veronii challenge. The four genes studied were nucleotide‐binding oligomerization domain 1 (NOD1), lipopolysaccharide‐binding protein (LBP), natural killer‐lysin (NKL), and interleukin‐1 beta (IL‐1β).ResultThe four genes showed significant transcriptional upregulation in response to infection. At 72 h postchallenge, the highest NOD1 and IL‐1β expression levels were recorded in the spleen, whereas the highest LBP and NKL expression levels were found in the gills. Pairwise distances of the data points and the hierarchical relationship showed that NOD1 clustered with IL‐1β, whereas LBP clustered with NKL; both genes within each cluster showed a significant positive expression correlation. Tissue clustering indicated that the responses of only the gill and intestine exhibited a significant positive correlation.ConclusionThe results suggest that NOD1, LBP, NKL, and IL‐1β genes play pivotal roles in the early innate immune response of Nile Tilapia to A. veronii infection, and the postinfection expression profile trends of these genes imply tissue‐/organ‐specific responses and synchronized co‐regulation.

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Virulence genes contributing to Aeromonas veronii pathogenicity in Nile tilapia (Oreochromis niloticus): approaching the development of live and inactivated vaccines

et al. 2022

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This study aimed to develop and evaluate live and inactivated vaccines to Aeromonas veronii pathogenicity in Nile tilapia. Therefore, five well-identified Aeromonas veronii isolates, including A (HY1), A (HY2), A (HY3), A (HY4), and A (HY6) isolated from diseased Nile tilapia (Oreochromis niloticus), were used for vaccine preparation. Virulence genes detected by a polymerase chain reaction (PCR) and lethal dose determination were conducted. Nile tilapia, each with a body weight of 25 ± 0.5 g were divided into six experimental groups (each of 20): T1 group (control), fish were injected with saline as a negative control, T2 group (formalin-killed vaccine) for the A (HY2) strain, T3 group ( formalized killed vaccine) for the A (HY4), T4 group (autoclaved vaccine) for the A (HY2), T5 group (autoclaved vaccine) for A (HY4), and T6 (live vaccine) for A (HY1), triplicate. At the end of the immunization period, all groups were challenged by A. veronii, A (HY2). Blood samples were drawn 21 days post-immunization and 3 days after the challenge test for antibody titer assay. The results showed that the pathogenicity of strains A (HY2) and A (HY4) was the strongest, as the lethality rates (LR) were 100% and 90%, respectively, whereas the pathogenicity was moderate for strains A (HY3) and A (HY6) (LR 60% for each). A (AY1) was the weakest strain as no dead fish was found for this strain. The presence of alt, act, aerolysin, lipase, and fla genes as the main cause of the pathogenesis. The best protective efficacy was obtained from the live vaccine, A (HY1) with a protective rate of about 94.12% (relative percentage of survival, RPS), compared to autoclaved killed vaccines and formalin-killed vaccines. Based on immunoglobulin estimation (IgM) and RPS%, our data concluded that A (HY1) live vaccine had the best vaccine prophylactic effect against the highly pathogenic strain A(HY2).

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Insight into summer mortality syndrome in farmed Nile tilapia (Oreochromis niloticus) associated with bacterial infection.

Cited by 8 publications

References 21 publications

Aeromonas veroniidetection in Egyptian fish farms with summer tilapia mortality outbreaks and the role of formic acid in limiting its spread

Aeromonas veroniidetection in Egyptian fish farms with summer tilapia mortality outbreaks and the role of formic acid in limiting its spread

Expression profiles of four Nile Tilapia innate immune genes during early stages of Aeromonas veronii infection

Virulence genes contributing to Aeromonas veronii pathogenicity in Nile tilapia (Oreochromis niloticus): approaching the development of live and inactivated vaccines

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