Hemopoietic Organs Research Articles

Влияние облучения на заболевания крови среди участников ликвидации последствий аварии на Чернобыльской атомной электростанции с учётом мультиморбидности состояний пациентов

The statistical relationships between radiation doses and blood diseases with the account of the multimorbidity factor in the Russian cohort of workers involved in mitigation of the consequences of the accident at the Chernobyl NPP have been investigated. For analysis observation data accumulated from 1986 over 2022 kept in the National Radiation Epidemiological Register were used. The size of the liquidators cohort was 89,578 men. During the follow-up period 6,013 blood disorders (D50-D89 ICD-10) were detected for the first time. The average radiation dose in the cohort was 0.13 Gy, and the average age at the first exposure was 33.6 years. Common approaches to data mining (Data Mining) were used to identify statistical relationships between blood diseases and other diseases; for radiation risk assessment, logistic regression models were used to link disease probability to radiation dose. The effect of low-dose radiation (less than 0.3 Gy) on blood diseases is statistically significant and is characterized by a multiplicative linear no-threshold model, the dose-response model with ERR/Gy=0.59 at 95% CI (0.23; 0.99). When considering multimorbidity in patients, the blood diseases radiation risk change was not statistically significant. Radiation risks several times higher than risks of malignant neoplasms, were found in three groups of diseases: 1) blood and haemopoietic organs other than anaemia and hemorrhages (D70-D77), with ERR/Gy=2.25; 2) immunodeficiency states (D80-D89), with ERR/Gr=2.01; 3) aplastic anemias (D60-D61), with ERR/Gy=5.56. The inclusion of aplastic anaemia in the officially approved list of diseases caused by exposure to ionizing radiation in Russia should be considered as scientifically justified document. The list may need to be supplemented by diseases of blood and haemorrhagic organs other than anaemia and hemorrhage, as well as immunodeficiency conditions. The radiation risk coefficients (ERR/Gy) for the main groups of blood diseases estimated for the first time will make it possible to establish radiation dependence in exposed people with the use of a dose and radiation-epidemiological approach, estimating the attributive fraction of radiation in the etiology of each specific disease case.

Study of subchronic oral toxicity of Altric-Extra drug in laboratory animals

The purpose of the research is to determine main toxicological parameters in repeated intragastric administration of Altric-Extra for veterinary use to laboratory outbred rats.Materials and methods. White outbred rats were used as a test system in the study. The experiment used clinical, toxicological, biochemical and morphological research methods.Results and discussion. Altric-Extra doses of 325 and 650 mg/kg were toxic for the laboratory animals. When administered daily intragastrically to the rats in the above doses, the drug had a negative effect on the functional status of the hemopoietic organs, and excretory and digestive systems. The main target organ for this drug is the thymus. Functional disorders in the above organs and systems are irreversible as evidenced by the post-mortem examination, general blood analysis, and biochemical blood test obtained 10 days after the drug administration was completed.

Analysis of the Development of B-Cell Precursors in Day Three Incubated Chicken Embryos

Background: In mammals, birds, and amphibians, the B lineage of lymphoid cells first arise during embryogenesis and are distinguished by their capacity to produce immunoglobulin. For the purpose of researching the development of the B-cell repertoire and the development of self-tolerance, these early B-cell precursors are of utmost importance. The genetic and/or microenvironmental variables that control the beginning of immunoglobulin synthesis in embryonic haemopoietic cells are, however, poorly understood. Purpose: The ontogeny of B-cell precursors in chicken embryos from day three of incubation was examined in this work. Research methods: The terms "ontogeny, B-cell, precursors, chicken embryos, incubation" were used in a thorough literature search in the PubMed, NCBI, and Google Scholar databases. After all articles were picked based on the inclusion and exclusion criteria, 38 papers that satisfied the criteria for inclusion were collected. Result: The study's findings show that clglarge basophilic hemopoietic stem cells and cIg+ small lymphoid B-cell precursors are two types of migrant cells that appear to enter the embryonic bursa of Fabricius. Hence, B lymphopoiesis does not only take place in the bursa of Fabricius in the avian embryo. Although the yolk sac and the hemopoietic tissues around the dorsal aorta are strong candidates, the identity of the extra-bursal location remains unknown. Conclusion: Hence, general haemopoietic organs may serve as the initial site of B lymphopoiesis in both birds and mammals. Only later in the course of avian development do the bursal follicles become accessible and take over.

Destabilization Processes in the Hemopoietic Organs of Goldfish as a Consequence of the Survival Strategy of Cestode Ligula (Digramma) interrupta (Cestoda: Pseudophyllidea)

Destabilization Processes in the Hemopoietic Organs of Goldfish as a Consequence of the Survival Strategy of Cestode Ligula (Digramma) interrupta (Cestoda: Pseudophyllidea)

Peracetic acid treatment of Ichthyophthirius multifiliis (Ciliophora: Ichthyophthiriidae) and Trichodina spp. reduces the infection by Aeromonas hydrophila and improves survival in Nile tilapia (Oreochromis niloticus)

Co-infections with ectoparasites and bacteria commonly occur in fish farms and are associated with high mortality. In March 2020, a private Nile tilapia (Oreochromus niloticus) farm in Sharkia Governorate, Egypt, experienced high fish mortality, and the clinically diseased fish were characterized by lethargy, abnormal swimming behavior, loss of appetite, skin hemorrhages, exophthalmia, and abdominal distension. Laboratory parasitological and bacteriological examinations of the diseased fish revealed concurrent infections with Ichthyophthirius multifiliis, Trichodina centrostrigeata, and Aeromonas hydrophila. Pathological findings indicated severe gill and skin infections with I. multifiliis and T. centrostrigeata associated with necrosis, hemorrhages, and depletion of the hemopoietic organs, as well as cardiac inflammation. Peracetic acid (PAA) was applied as a strong oxidizing antimicrobial disinfectant, and in vitro evaluation showed that 5 ppm achieved 5-log reductions in the viable colony count of A. hydrophila after a contact time of 5 min and 1.076 ppm represented the 4-h 50% lethal concentration (LC50) for the infective stage of I. multifiliis (theronts). The continuous exposure of culture water to 1 mg L−1 PAA for 1 week followed by periodical use of PAA at the same concentration twice per week was effective in eradicating the ciliated protozoans, reducing the aerobic bacterial density in water, ameliorating the pathological alterations, restoring the fish health, and reducing the mortality rate by up to 15%. Thus, the use of PAA to treat I. multifiliis and T. centrostrigeata reduces the infection by A. hydrophila in Nile tilapia and improves their survivability.

Impact of the Injection Site on Growth Characteristics, Phenotype and Sensitivity towards Cytarabine of Twenty Acute Leukaemia Patient-Derived Xenograft Models.

Rodent models have contributed significantly to the understanding of haematological malignancies. One important model system in this context are patient-derived xenografts (PDX). In the current study, we examined 20 acute leukaemia PDX models for growth behaviour, infiltration in haemopoietic organs and sensitivity towards cytarabine. PDX were injected intratibially (i.t.), intrasplenicaly (i.s.) or subcutaneously (s.c.) into immune compromised mice. For 18/20 models the engraftment capacity was independent of the implantation site. Two models could exclusively be propagated in one or two specific settings. The implantation site did influence tumour growth kinetics as median overall survival differed within one model depending on the injection route. The infiltration pattern was similar in i.t. and i.s. models. In contrast to the s.c. implantation, only one model displayed circulating leukaemic cells outside of the locally growing tumour mass. Cytarabine was active in all four tested models. Nevertheless, the degree of sensitivity was specific for an individual model and implantation site. In summary, all three application routes turned out to be feasible for the propagation of PDX. Nevertheless, the distinct differences between the settings highlight the need for well characterized platforms to ensure the meaningful interpretation of data generated using those powerful tools.

New molecular markers involved in immune system homeostasis and hemopoietic organ development are differentially regulated during oocytes in vitro maturation

Abstract The growth and maturation of the oocyte is a dynamic process which requires a variable supply of hormones, growth factors and energy. These needs are met partially by the surrounding somatic cells and the cumulus-oocyte complex, which communicate bi-directionally via gap junctions. Identifying and analyzing protein expression in the oocyte can provide insight in its development and growth. Further, like bone marrow stem cells, if relevant marker genes are found in oocytes, there is a potential for the oocyte to be manipulated into becoming hemopoietic stem cells. In this study, porcine oocytes were isolated and subjected to microarray analysis to compare the oocyte gene expression in vivo and in vitro maturation (IVM). Genes identified belonged to both ‘hemopoietic or lymphoid organ development’(GO:0048534) and ‘immune system development’ (GO:0002520), and the markers can be used to identify several activities such as cell migration, neurogenesis and proliferation. The following are the identified genes and all were downregulated after IVM to varying degrees: ID2, VEGFA, TGFBR3, INHBA, CDK6, BCL11A, MYO1E, ITGB1, EGR1, NOTCH2, SPTA1, KIT and TPD52. Our results should provide new markers to further investigate oocyte development and growth regulation. Running title: Markers of hemopoietic organ development

Monitoring of public health in the Kashagan oil and gas field

According to explored hydrocarbon reserves the Republic of Kazakhstan (RK) is among ten top countries rich in oil deposits. In connection with the intensive development of oil and gas industry environmental protection and public health issues became subject of a great interest from both scientists ’ and health practitioners ’ side. Results of the study included in this article are devoted to the study of health of the population, living near the “Bolashak” installation of complex preparation of oil and gas. There is a preliminary oil refining process coming from the Kashagan field and its further export. Analysis proved air pollution to be the one of the major risk factors for the health of the residing people. In the area there are problems of fresh water supply and frequent accidents at sewage plants. Landfills for municipal solid waste does not meet sanitary standards. The health care system of Makat district is characterized by uncompleted personnel and lack of beds. Indices of the mortality rate over the study period declined by 28.8%. As a result, population growth over the study the period was characterized by a tendency to increase. In 2013 population sought medical advice due to respiratory diseases, injuries and poisoning, diseases of blood and hemopoietic organs, diseases of the skin and subcutaneous tissue and nervous system.

РАЗВИТИЕ И ФУНКЦИОНАЛЬНАЯ ОРГАНИЗАЦИЯ ЦЕНТРАЛЬНЫХ ОРГАНОВ ГЕМОПОЭЗА ЛИЧИНОК ЛЕЩА ОБЫКНОВЕННОГО (ABRAMIS BRAMA (L.))

The article dwells upon physiological and morphological studies of fish carried out on a large scale, due to the need to control their reproduction and assess the impact of living conditions on the body of fish. Currently, a large amount of data on hematopoietic organs and the formation of blood cells in fish have been accumulated, but the facts are quite contradictory. At the same time, the state of the hematopoietic system can be justified only according to histogenesis of hematopoietic organs. From the results of examining reticular intercanal tissue of the head kidney (pronephros) of bream, a typical representative of bony fish, it can be inferred that pronephros is one of the main hemopoietic organs, in which the process of developing red blood cells and leukocytes takes place, with the majority of cells accounted for blood cells of erythropoietic series. Pronephros loses its excretory function in the early stages of ontogenesis. Throughout its development pronephros is presented as a dense formation, in the intercanal tissue of which there is reticular tissue with numerous hematopoietic elements. Active hematopoiesis occurs in mesonephros (trunk kidney) of bream larvae. The study of the morphophysiology of mesonephros in ontogenesis showed that this organ forms blood elements of all series, with more than half of the hematopoietic elements accounted for erythropoietic cells. The excretory function of the trunk kidney is maintained throughout the whole period of the organ developing. Thus, mesonephros of bream is also one of the main organs of hematopoiesis represented by a paired organ which stretches along the spine.

Hemogram and iron indices in renal anemia and the amelioration with Carica papaya leaf extract applied on albino rat model.

The present study was designed to look at the hematological disorders in gentamicin nephrotoxicity model, as kidney is considered as one of the hemopoietic organs. In a previous study, novel and classical kidney injury biomarkers were utilized to evaluate the nephroprotective potential of Carica papaya leaf extract (CPLE) in the same model in albino rats. Gentamicin (100 mg/kg, subcutaneously, for 21 consecutive days) resulted in significant decreases in red blood cell (RBC) count, hemoglobin concentration (HGB), and packed cell volume (PCV) value, with minimal alterations in erythrocytic indices. Leucogram showed leukocytosis, granulocytosis, and thrombocytopenia. Erythropoietin (EPO) levels were also drastically decreased by the end of the experimental course. Serum iron, unsaturated iron-binding capacity (UIBC), total iron binding capacity (TIBC), transferrin saturation %, and serum transferrin concentration values were significantly decreased in contrast to ferritin, which was increased. When concurrently administered with gentamicin, CPLE (150 and 300 mg/kg, orally via gastric tube, for 21 days) significantly protected against the drastic effects of the former on the blood profile with improving potentials on erythrogram, leukogram, thrombocytes, EPO, iron and its indices, in a dose-dependent manner. These data may suggest CPLE as an appreciated blood homeostatic and nephroprotective agent from a natural source that could be a good remedy in conditions associated with blood disorders.

Эффекты влияния электромагнитного поля радиочастотного диапазона на органы кроветворения у экспериментальных животных

Цель - оценка влияния электромагнитного излучения радиочастотного диапазона на органы кроветворения самок и самцов мышей линии СВА. Методика. Опытные группы животных подвергали воздействию электромагнитного излучения радиочастотного диапазона (диапазон сотовой связи) с интенсивностью 1,2 мВт/см2, периодом экспозиции 10 мин ежедневно в течение 5 сут. Через 30 сут с момента начала облучения часть животных выводили из эксперимента для исследования органов кроветворения, другую часть спаривали для получения потомства. Результаты. Установлено, что воздействие исследуемого фактора вызывает статистически значимые изменения в красном костном мозге, селезенке, тимусе, периферической крови у экспериментальных животных и их потомства. Через 30 сут у облученных самок мышей в крови возрастало количество эритроцитов, у половозрелых самцов количество эритроцитов уменьшалось. Содержание гемоглобина изменялось однонаправленно у облученных самок и самцов, что проявлялось тенденцией к снижению его уровня. У самцов и самок отмечалось снижение числа нейтрофилов. Число лимфоцитов у самцов было в пределах нормы, у самок отмечалась тенденция к увеличению доли лимфоцитов. Однонаправленные изменения у самок и самцов отмечены в эритроидном ростке - уменьшение числа полихроматофильных и оксифильных нормоцитов, вследствие ускоренного созревания клеток и их выхода в кровь. В тимусе облученных самок и самцов уменьшалось число ядросодержащих клеток, в селезенке, напротив, их число увеличивалось. У потомства облученных животных снижалось число лейкоцитов с увеличением доли юных и палочкоядерных нейтрофилов, доля лимфоцитов снижалась по сравнению с потомством необлученных животных. Заключение. Выявленные изменения расцениваются как компенсаторно-приспособительные реакции в органах кроветворения у экспериментальных животных. The purpose - identify the effects of the influence of electromagnetic radiation (EMR) at the radio frequency band hemopoietic organs of males and females CBA mice in different models of irradiation. Methods. The experimental group of animals exposed to RF EMF with an intensity of 1.2 mW / cm2 exposure period of 10 minutes daily for 5 days. After 30 days from the start of irradiation of the animals were taken out of the experiment for the study of blood, the other part mated to produce offspring. Results. It was found that when exposed to the test factor there was a significant change in the bone marrow, spleen, thymus, peripheral blood of experimental animals and their offspring. The findings indicate the development of compensatory and adaptive reactions of the blood of experimental animals.

MALIGNANT NEOPLASMS IN THE REPUBLIC OF BURYATIA: A RETROSPECTIVE ANALYSIS

Introduction. The problem of the carcinogenic danger of the gain in cancer incidence in large cities and industrial centers is under consideration, but there are no studies on the epidemiological and hygienic aspects of the prevalence of cancer pathology in the regions of Siberia. Material and methods. Incidence and mortality rates of malignant tumors were studied as in general as corresponding to the leading localizations in accordance with the International Classification of Diseases for 1991-2015. To reduce the uncertainties of the analysis associated with the small population of the rural areas of the Republic of Buryatia (RB), the average value for five-year periods was calculated. Results. The epidemiological analysis of the long-term morbidity and mortality rate in cancer cases indicates negative trends. The gain in cancer prevalence was revealed to be 1.5 times higher in the RB. The increase of the index value is especially pronounced in the following localizations: blood and hemopoietic organs by 2.8 times, genitourinary system - 2.8 times, endocrine system - 2 times, digestive organs - 1.5 times. Malignant neoplasms of the lungs (33.3 ‰00 of the population) and the stomach (28.1 ‰00) are most often recorded. Using repeated georeferenced measurements of oncological pathology from the general population in the RB, we identified clusters highlighting a particular structure in the spatial distribution of high and low values of the mortality and incidence rate. Conclusion. The further direction of research is discussed: a detailed study of the impact of carcinogenic risk factors (industrial, natural and climatic origin, lifestyle) and the organization of medical care for the population in identified areas of risk.

РАЗВИТИЕ КРОВИ КАК ТКАНИ В РАННЕМ ОНТОГЕНЕЗЕ КЛАРИЕВЫХ СОМОВ (CLARIAS GARIEPIUS)

The study of the growth of blood cells and hemopoietic organs of claravia catfish ( Clarias gariepius ) grown in the closed loop water systems on the basis of "RANTOP AGRO-5" LLC in the Krasnodar region. Test materials (prolarvae and larvae aged 5, 10, 15, 20 and 25 days of active feeding) were selected in the spring-summer period of 2013-2014. Prolarvae in mesenchyma of forming mesonephros which begins to develop after hatching had primordial precursor cell and blast blood cells between forming vesicles. There took place differentiation of erythropoietic cells: erythroblasts, pronormoblasts and basophilic normoblasts. Accumulation of hemoglobin in erythrocytes indicates that since the first day of hatching, the blood starts to perform transport function - transportation of oxygen. The rudiment of thymus was observed in larvae aged 10 days. This organ generated lymphocytepoietic cells. The central hemopoietic organ - spleen - was originally registered as a mesenchymal rudiment at the age of 10 days. At the age of 25 days, development of the organ stroma is not finished in clarid catfish larvae. Reticular tissues develop actively. Separate lymphoid clumps in the spleen structure have not been found. Melano-macrofagic centres are also unformed. Qualitative analysis of haemopoiesis showed that in spleen there take place development of all types of blood cells: erythropoiesis, granulopoiesis and agranulopoiesis.

Black Scorpionfish (Scorpaena porcus) Hemopoiesis: Analysis by Flow Cytometry and Light Microscopy.

Cell suspensions of head kidney and spleen of black scorpionfish (Scorpaena porcus L.) have been studied using flow cytometry and light microscopy. On the basis of forward scatter (FS) and side scatter (SS) distribution and light microscopy, two main types of cells in the hemopoietic organs were identified: "small cells" (5.1-8.9 µm) and "large cells" (10.8-15.3 µm). Subpopulation of small cells was formed by thrombocytes, lymphocytes, and elements with functionally inactive nuclei. Euchromatin level in their nuclei was low and acidophilic cytoplasm corresponded to negligible nucleic acids content. No proliferative activity was observed using SYBR Green I fluorescence analysis. Morphological characteristics of these cells coincided with colony forming units of mammals. Large cells in head kidney consisted of two subpopulations of cells differing in granularity and DNA content. Proliferating blast cells and differentiating cells of all hemopoietic lines were identified among them. Macrophages and apoptotic cells were also detected in head kidney. In spleen large cells cluster mainly included aged red blood cells with extended lengthwise axis. Blast cells and differentiating elements in spleen were not observed. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:1993-1999, 2017. © 2017 Wiley Periodicals, Inc.

Gene expression and regulation of molecules involved in pharynx inflammatory response induced by LPS in Ciona intestinalis

In the ascidian Ciona intestinalis, the pharynx (hemopoietic organ) connects the external environment to the gastrointestinal system for two main activities, respiration and food collection, potentially exposing the ascidian to high concentrations of pathogenic microorganisms. Recently, evidence in C. intestinalis has indicated that the pharynx is involved in the inflammatory reaction induced by lipopolysaccharide (LPS) injection into the body wall. Immune-related genes such as cytokines, galectins, pro-PO, CAP are expressed in pharynx hemocytes and are up-regulated by the inflammatory agent LPS. Studies of the expression pattern of the immune gene clearly show that in C. intestinalis, as in vertebrates, immune gene expression can be regulated through Alternative Polyadenylation (APA) Mechanism and GAIT element al 3’UTR.

Effect of ranching time on melanomacrophage centres in anterior kidney and spleen of Southern bluefin tuna, Thunnus maccoyii

Melanomacrophage centres (MMCs) are common in the haemopoietic tissue of fish and are an important component of the humoral immune response. Increasingly they are being studied as a biomarker of environmental stress in both wild and aquaculture fish stocks. Computer image analysis of histological sections of the head kidney and spleen of ranched Southern bluefin tuna (SBT) was used to investigate changes in MMCs over various stages of the ranching cycle. Histochemical pigment differentiation indicated haemosiderin, lipofuscin and melanin were present in MMCs of both the kidney and spleen, with kidney MMCs being highly positive for lipofuscin and melanin and spleen having high levels of haemosiderin and a lower level of melanin than kidney. The MMC area in the kidney of wild sampled SBT ranged from 0.41 ± 0.13% to 2.95 ± 0.26% and that in the spleen ranged from 0.35 ± 0.09% to 2.75 ± 0.86%. The MMC area in the spleen of SBT increased over the latter stages of ranching and at harvest compared to SBT sampled in the wild and at the end of tow. There was no statistically significant difference in the MMC area in the kidney of ranched SBT sampled at various stages. SBT appear to have a higher MMC area in haemopoietic organs than numerous other fish species, perhaps providing a greater capacity to deal with ‘wear and tear’ and increased immune-competence.

Сердечно-сосудистая система и кроветворные органы

Сердечно-сосудистая система и кроветворные органы

Effects of acoustic and EHF impulses on multipotent stromal cells during formation of bone marrow containing heterotopic organs in tissue engineered constructions.

We studied the effects of physical factors (acoustic impulses of laser-induced hydrodynamics, AILIH, and EHF-radiation) on the formation of heterotopic bone marrow organs. Suspension of precipitated mouse bone marrow cells was exposed to AILIH and EHF or their combinations (AILIH+EHF, EHF+AILIH). The developed tissue engineering constructions (gelatin sponges containing 107 nucleated bone marrow cells exposed to physical factors) were transplanted under the renal capsule of syngeneic mice. Analysis of newly formed hemopoietic organs was performed after 3 and 5 months. The total amount of hemopoietic cells, number of multipotent stromal cells, efficiency of colony formation from these cells, and weight of bone capsule of the transplants were measured. Microscopic study showed that 5-month transplants were significantly larger than 3-month transplants and contained 3-fold more hemopoietic cells (20-fold in the AILIH+EHF group). The number of multipotent stromal cells was maximum in EHF+AILIH group (by 2.2 times higher than in the control) and minimum in AILIH+EHF group. Exposure to EHF+AILIH had most pronounced effect on the formation of the bone marrow transplants. The weight of bone capsules more rapidly increased in gelatin sponges of 3-month transplants of EHF+AILIH and AILIH groups. These data suggest that the studied physical factors can be used for acceleration of rehabilitation process.

In vitro characterization of 6-Coumarin loaded solid lipid nanoparticles and their uptake by immunocompetent fish cells

The primary aim of the present work was to evaluate the in vitro uptake of 6-Coumarin (6COUM) loaded solid lipid nanoparticles (SLN) by two gilthead seabream (Sparus aurata L.) cell types: an established cell line (SAF-1 cells) and the primary cultures of head-kidney (HK)—the main haemopoietic organ in fish, equivalent to mammalian bone marrow—leucocytes. For this purpose, after the physicochemical characterization of SLN, the uptake by those immunocompetent fish cells was evaluated using flow cytometry and confocal microscopy. Concomitantly, the uptake of 6-COUM loaded SLN was compared with that achieved with 6-COUM loaded pectin microparticles (MPs), which were selected as a competitor of the delivery carriers. After SLN and MP physicochemical characterization, the results demonstrated that SAF-1 cells were able to internalize high percentages of 6-COUM SLNs when incubated for 4, 8 and 24h, with the highest SLN concentration tested (10μg/ml). The ability of HK leucocytes to internalize SLN was also found to vary depending on both incubation time and SLN concentration. The highest values of HK leucocytes internalizing SLN particles (around 16%) were detected at the maximum SLN concentration (20μg/ml) at incubation times of 4 or 8h. Conversely, HK leucocytes were unable to internalize MPs at any tested concentration and incubation time. A possible mechanism explaining the uptake into cells is proposed. The present work constitutes the first approximation to consider SLN as nanocarriers for delivering biologically active substances to fish.

Caligus Elongatus and Photobacterium Damselae Subsp Piscicida Concomitant Infections Affecting Broodstock European Seabass, Dicentrarchus Labrax, with Special Reference to Histopathological Responses

Caligus elongatus and Photobacterium damsela subsp piscicida are pathogens of serious infections in European seabass, Dicentrarchus labrax. In this study, both agents were concomitantly isolated from moribund broodstock European seabass cultured within the hatchery unit at El-Max Research Station (NIOF), Alexandria governorate, Egypt. Externally, fish were heavily infested with Caligus elongatus ectoparasitic copepods. The overall prevalence, mean intensity and mean abundance of C. elongatus on examined fish were 92.3%, 23.3 and 21.5; respectively. Majority of samples noticed sever haemorrhages on the external body surface and fins. Internally, moribund fish showed characteristic whitish nodules and extensive adhesions of visceral organs. 88.46% of investigated fish were concurrently found to be infected with P. damsela subsp piscicida. No other bacterial species were detected. P. damsela subsp piscicida was also isolated from C. elongatus infesting clinically diseased fish. All P. damsela subsp piscicida isolates were confirmed by sequencing of the16S rRNA gene. Microscopically, multiple granulomas were regularly observed in haemopoietic organs. Our results as a whole indicate that C. elongatus may serve as a potential vector for P. damsela subsp piscicida and possibly enhance photobacteriosis dissemination among cohabitant fish, thus suggesting the desirability of redesigning the protocols presently used for microbial recognition during fish epidemiological studies to improve fish health.