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Manal I. El-barbary - One of the best experts on this subject based on the ideXlab platform.
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First recording of Shewanella putrefaciens in cultured Oreochromis niloticus and its identification by 16Sr RNA in Egypt
The Egyptian Journal of Aquatic Research, 2017Co-Authors: Manal I. El-barbaryAbstract:A survey to determine the pathogenic bacterial strains of an important commercial capture fish, Oreochromis niloticus in an Egyptian fish farm was conducted. One strain presumptively identified as Shewanella putrefaciens was isolated from the fish and identified by a biochemical test, API20NE system and 16S rRNA gene. Intraperitoneal (I.P) challenge by S. putrefaciens revealed its pathogenicity with 50% mortality. The infected fish showed skin hemorrhage, Fin Rot and shallow necRotizing ulcers on the skin with congestion and enlargement of the liver, spleen and kidneys. The antibiogram of S. putrefaciens revealed its sensitivity to ciprofloxacin, norfloxacin, nalidixic acid, streptomycin, gentamycin, oxytetracyclin and sulfamethoxazole. Complete resistance to cephazolin and fusidic acid was recorded. Histological changes in the liver of infected O. niloticus included hepatocyte degeneration, fatty vacuolation in liver cells, Kupffer cell increase, hemolysis with infiltration in blood vessels, deposition of hemosiderin associated with the liver blood vessels and necrosis hepatocytes in the fatty liver tissue. The results concluded that the S. putrefaciens should be considered as an opportunistic pathogen for fish, which had caused fish infections, diseases with septicemia and mortality in O. niloticus.
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Vibrio harveyi infection in Arabian Surgeon fish (Acanthurus sohal) of Red Sea at Hurghada, Egypt
The Egyptian Journal of Aquatic Research, 2013Co-Authors: Mahmoud Hashem, Manal I. El-barbaryAbstract:Vibrio harveyi causes vibriosis to marine ornamental Arabian surgeon fish (Acanthurus sohal) the disease appeared and spread rapidly in fish in the indoor aquarium of the National Insti- tute of Oceanography and Fisheries (NIOF) in Hurghada (Egypt). The pathogen was isolated from skin ulcers in head and body, and internal organs of randomly collected samples of diseased fish using tryptic soy agar and thio-sulfate citrate bile salt sucrose agar plates. Lethargic, off food, hem- orrhagic skin ulcers in head and body varies between superficial and deep skin depigmentation, hemorrhagic spots and Fin Rot were the main clinical signs appeared on the naturally infected fish. All isolates of the bacterium constituted a homogeneous phenotypic group and were identified by morphological characterization, biochemical tests and API20E as V. harveyi. The isolated strain was sensitive to ciprofloxacin, streptomycin, chloramphenicol and kanamycin. a 2013 Production and hosting by Elsevier B.V. on behalf of National Institute of Oceanography and Fisheries.
A.d. Vethaak - One of the best experts on this subject based on the ideXlab platform.
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Disease prevalence in flounder (Platichthys flesus) from the Dutch Wadden Sea as indicator of environmental quality: A summary of 1988-2005 surveys
Journal of Sea Research, 2013Co-Authors: A.d. VethaakAbstract:Abstract In 1988, epizootics of ulcer disease in the flatfish flounder in the Dutch Wadden Sea were reported near freshwater drainage sluices of IJsselmeer Lake, locally affecting up to 38.9% of fish. Other diseases such as Fin Rot and lymphocystis were less frequent, but followed a similar pattern. Results of follow-up surveys in the Wadden Sea in 1994–2005 confirm previous Findings and also show significantly elevated ulcer prevalences at other smaller drainage works. The most likely stress factors that contributed to the development of the epizootics at these sites include osmotic stress, adverse water quality conditions including chemical contaminants, nutritional deficiencies, and obstruction to fish migration. It was shown that discharges of IJsselmeer Lake freshwater in 1988–96 had a wide effect on the prevalence and distribution of ulcers and lymphocystis in the western Wadden Sea. A general reduction in disease prevalence in flounder in the entire Dutch Wadden Sea was observed during 1988–2005, which was most likely due to a general improvement in water quality and locally improved habitat conditions for flounder near drainage sluices. Ulcer prevalences outside the two IJsselmeer Lake sluices (Den Oever and Kornwerderzand) declined in this period from approximately 30% to 10% for medium-sized fish. Other skin diseases have also displayed a downward trend at both sites in recent years, with prevalences falling sharply to below 1%. Elsewhere in the Wadden Sea and the Ems–Dollard estuary, disease prevalences have declined towards natural background levels (
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skin and liver diseases induced in flounder platichthys flesus after long term exposure to contaminated sediments in large scale mesocosms
Environmental Health Perspectives, 1996Co-Authors: A.d. Vethaak, J G Jol, A Meijboom, M L Eggens, T Rheinallt, P W Wester, T Van De Zande, A Bergman, N Dankers, Freek ArieseAbstract:Disease development in flounder (Platichthys flesus) was studied over a period of 3 years in three large mesocosms (40 m x 40 m x 3 m). Two of the mesocosms contained clean sand and the third, sharing a common water circulation with one of the clean-sand mesocosms, was stocked with contaminated dredged spoil. In this way, one of the clean-sand mesocosms was indirectly polluted via the water phase, and analysis of contaminant concentrations in sediments and flounder tissues showed that it had a status intermediate between the other two. Random samples of the flounder populations from the indirectly polluted and reference mesocosms were examined every 2 months for epidermal diseases (lymphocystis, skin ulcers, Fin Rot) and then released. In addition, every 6 months, random samples of fish from all three mesocosms were sacrificed for histological and chemical investigation. With regard to the development of epidermal disease, the results showed little difference between the reference mesocosm and the indirectly polluted mesocosm, with the exception that lymphocystis was significantly elevated in the indirectly polluted mesocosm. Although pollution may be a risk factor in the etiology of this disease, such a relationship would probably be obscured under field conditions due to variation arising from other factors. Histopathological analysis of the livers revealed in total four cases of hepatocellular adenoma (1.5% of sampled population) in fish from the polluted mesocosms, the first occurring after 2.5 years of exposure in fish from the indirectly polluted mesocosm. Furthermore, several other liver lesions, including foci of cellular alteration and hydropic vacuolated lesions, developed during the course of the experiment before tumor formation was apparent. Prevalences of these conditions were very much lower in the reference mesocosm than in the two polluted mesocosms. Densities of melanomacrophage centers in the liver showed a similar trend. The Findings clearly indicate that long-term exposure to chemically contaminated dredged spoil can induce liver neoplasia and other liver lesions in flounder at contaminant levels comparable to those found in the natural environment.
Ronald Goldberg - One of the best experts on this subject based on the ideXlab platform.
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The effects of Fin Rot disease and sampling method on blood chemistry and hematocrit measurements of winter flounder, Pseudopleuronectes americanus from New Haven Harbor (1987--1990).
Marine pollution bulletin, 2008Co-Authors: J. Ziskowski, Renee Mercaldo-allen, Jose J. Pereira, Catherine A. Kuropat, Ronald GoldbergAbstract:Winter flounder from New Haven, Connecticut were evaluated for Fin Rot disease. Blood samples collected from healthy and diseased fish were used to measure bilirubin, calcium, hematocrit, inorganic phosphorus, osmolality, and total pRotein. Blood measurements were significantly affected by the presence of Fin Rot disease and by sampling mode (bled immediately or after 18 h). A reduction in blood chemistry values was associated with Fin Rot disease. Logistic regression modeling was used to identify explanatory variables contributing to the Fin Rot outcome in winter flounder. Blood constituent levels were higher in fish bled immediately versus 18 h post-capture, especially among fish without Fin Rot, suggesting that a waiting period is necessary for blood values to stabilize following initial sampling stress. This study presents evidence that winter flounder blood chemistry and hematocrit measurements are affected by Fin Rot disease.
Erlinda R. Cruz-lacierda - One of the best experts on this subject based on the ideXlab platform.
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Vibrio harveyi-like bacteria associated with Fin Rot in farmed milkfish Chanos chanos (Forsskal) Fingerlings in the Philippines
Aquaculture, 2021Co-Authors: Erish G. Estante-superio, Rolando V. Pakingking, Valeriano L. Corre, Erlinda R. Cruz-lacierdaAbstract:Abstract Milkfish (Chanos chanos) is a commercially important species widely cultured and consumed in the Philippines. It is a hardy fish but due to culture intensification, occurrence of bacterial disease is inevitable. The causative agent of Fin Rot disease in milkfish Fingerlings (total length [TL] = 2.8–4.5 cm) reared in intensive nursery earthen ponds in the Philippines was investigated in the current study. Following biochemical characterization tests and 16S rRNA sequencing, seven isolates recovered from affected fish were identified as Vibrio harveyi-like bacteria. Immersion challenge of milkfish (TL = 5.64 ± 0.76 cm) using a representative strain (CCL-01) at inoculum dose of 108 CFU/mL resulted in Fin Rot as early as 1-day post-infection (dpi) and concomitant mortalities of 57% ± 0.58 at 7 dpi. Moreover, when milkfish (TL = 6.18 ± 0.66 cm) stocked at 5, 10, and 20 fish/5 L were exposed to the computed 168-h lethal dose (LD50) at 6.63 × 104 CFU/mL, significant mean mortality of 45% ± 1.0 coupled with typical signs of Fin Rot were particularly obtained in fish stocked at 20 fish/5 L (biomass = 4 g/L) while low mortality of 0% and 7% ± 0.58 were recorded in fish stocked at 5 fish/5 L and 10 fish/5 L, respectively, at 7 dpi. Vibrio harveyi-like bacteria was reisolated in lesions and kidney of all challenged fish while none in any of the control fish. The current data clearly indicate that the isolated V. harveyi-like bacteria is an opportunistic pathogen capable of instigating disease epizootics in milkfish Fingerlings stocked at higher densities.
J. Ziskowski - One of the best experts on this subject based on the ideXlab platform.
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The effects of Fin Rot disease and sampling method on blood chemistry and hematocrit measurements of winter flounder, Pseudopleuronectes americanus from New Haven Harbor (1987--1990).
Marine pollution bulletin, 2008Co-Authors: J. Ziskowski, Renee Mercaldo-allen, Jose J. Pereira, Catherine A. Kuropat, Ronald GoldbergAbstract:Winter flounder from New Haven, Connecticut were evaluated for Fin Rot disease. Blood samples collected from healthy and diseased fish were used to measure bilirubin, calcium, hematocrit, inorganic phosphorus, osmolality, and total pRotein. Blood measurements were significantly affected by the presence of Fin Rot disease and by sampling mode (bled immediately or after 18 h). A reduction in blood chemistry values was associated with Fin Rot disease. Logistic regression modeling was used to identify explanatory variables contributing to the Fin Rot outcome in winter flounder. Blood constituent levels were higher in fish bled immediately versus 18 h post-capture, especially among fish without Fin Rot, suggesting that a waiting period is necessary for blood values to stabilize following initial sampling stress. This study presents evidence that winter flounder blood chemistry and hematocrit measurements are affected by Fin Rot disease.