Increase In Total Hemocyte Count Research Articles

Evaluation of CpG-Oligodeoxynucleotides as Immunostimulants and Protecting Agents Against Aeromonas hydrophila in Freshwater Lobster (Cherax quadricarinatus)

MAS disease (Motyle Aeromonas hydrophila) is a prevalent bacterial infection that affects freshwater lobsters. This research aimed to evaluate the potential of CpG-ODN as an immunostimulant and protecting agent in Cherax quadricarinatus lobsters. The study was conducted at the Fish Health Laboratory, Pangkep State Polytechnic, Indonesia. The lobsters were divided into different groups and injected with three types of CpG-ODN (2133, 2006, 1668) or a control group using PBS. Parameters such as Total Hemocyte Count, Phagocytic Index, and Lysozyme Activity were measured at multiple time points, including before and after injection. CpG-ODN 2006 showed significant immunostimulant effects, as evidenced by a notable increase in total hemocyte count, phagocytic index, and lysozyme activity compared to the other CpG-ODN types. On the other hand, CpG-ODN 2133 exhibited potential as a protecting agent against Aeromonas hydrophila, as lobsters injected with this CpG-ODN demonstrated higher survival rates in the challenge test compared to the control group. These findings contribute to our understanding of immunostimulant strategies and protective mechanisms in freshwater lobsters. CpG-ODN, particularly CpG-ODN 2006, shows promise as an effective immunostimulant, while CpG-ODN 2133 exhibits potential as a protecting agent against A. hydrophila. Further exploration of CpG-ODN applications could lead to advancements in disease management in aquaculture.

Dietary administration of mangosteen, Garcinia mangostana, peel extract enhances the growth, and physiological and immunoendocrinological regulation of prawn, Macrobrachiumrosenbergii.

In this study, we investigated the potential immunostimulatory effects of mangosteen (Garcinia mangostana) peel extract on Macrobrachium rosenbergii, specifically in enhancing immunity and resistance against Lactococcus garvieae. We employed a dietary administration approach to assess the impact of different extract preparations from mangosteen peel, namely mangosteen peel powder (MPP), boiled mangosteen peel powder (MPB), and mangosteen peel extract (MPE). Following the administration of mangosteen peel extract, we evaluated growth performance, innate immune parameters, and disease resistance in the prawns. The results revealed a significant increase in total haemocyte count (THC), differential haemocyte count (DHC), phenoloxidase (PO) activity, respiratory bursts (RBs), as well as phagocytic activity and clearance efficiency against L. garvieae. Based on these findings, we suggest that mangosteen peel extract can be utilized as an immunostimulant for prawns through dietary administration, regulating immune responses and enhancing resistance against pathogens by modulating carbohydrate metabolism.

The effect of banana blossom on growth performance, immune response, disease resistance, and anti-hypothermal stress of Macrobrachium rosenbergii

Banana (Musa acuminata) blossom contains high nutritional value and bioactive compounds. In this study, Macrobrachium rosenbergii were fed with diets containing banana blossom powder (BBP) at 10 and 20 g kg−1, hot-banana blossom (BBH) extract at 10 and 20 g kg−1, and the basal diet for 56 days. The growth performance, physiological response and immune parameters were evaluated. The results showed that a significantly higher percentage weight gain (PWG) and percentage length gain (PLG) in prawns fed with BBH diet. The feed efficiency (FE) significantly increased in prawns fed BBP. The prawn fed both BBH and BBP diet showed higher survival rate than control group. The prawn fed with BBH showed a significant increase in total haemocyte count (THC) and different haemocyte count (DHC), whereas phenoloxidase (PO) activity and respiratory bursts (RBs) significant increase in prawns fed both BBP and BBH diet. Furthermore, M. rosenbergii fed with both BBP and BBH diets showed significantly higher phagocytic activity and clearance efficiency against Lactococcus garvieae infection. At the end of the 56 days of feeding trial, the susceptibility of prawns to L. garvieae infection and hypothermal (18 °C) stress were evaluated. The results showed that prawns fed BBH diets had a significantly higher survival rate against L. garvieae than those of fed with the basal diet. Anti-hypothermal stress was observed in prawns fed both BBP and BBH diets showing no significant difference in haemolymph glucose in prawns subjected to 18 °C and 28 °C, whereas the norepinephrine level in haemolymph of prawns fed with BBH diets subjected to 18 °C was significantly lower than in prawns subjected to 28 °C. In summary, we recommend addition of hot-banana blossom extract to the diet of M. rosenbergii at 20 g kg−1 to promote growth performance, improve physiological function, enhance immunity, increase anti-hypothermal stress, and to increase resistance against L. gavieae.

Fermented corn protein concentrate to replace fishmeal in practical diets for Pacific white shrimp Litopenaeus vannamei

The latest corn-based ingredient available in the market today is fermented corn protein concentrate (FCPC), which is expected to perform well in shrimp diets due to its nutritional profile and the probiotic properties of the product. The current study was conducted to evaluate the efficacy of FCPC as a replacement for fish meal (FM) in diets of Pacific white shrimps, Litopenaeus vannamei. Graded levels of FCPC (0, 4, 8, 11, 13 and 15 g/100 g) were used to replace fishmeal (16, 12, 8, 4, 2 and 0 g/100 g) in diet, which was evaluated over a 8-week growth trial (initial weight 0.17 ± 0.01 g; n = 3). At the conclusion, no significant differences were detected in growth, FCR, survival or haematological parameters of shrimp (p > 0.05). Results reveals the efficacy of FCPC to replace 100% fishmeal at an inclusion level as high as 15%, without compromising the performances of shrimp. Significant increase in total haemocyte count (THC) and astaxanthin level in shrimp in response to the inclusion level of FCPC was assumed to be due to the probiotic properties of fermented corn and due to the availability of bio-convertible carotenoids in FCPC, respectively.

Exposure to Decreased pH and Caffeine Affects Hemocyte Parameters in the Mussel Mytilus galloprovincialis

Combined effects of reduced pH, as predicted under climate change scenarios, and the most popular and widely used stimulant caffeine were assessed in hemocyte parameters of the mussel Mytilus galloprovincialis, being hemocytes involved in immune defense. Bivalves were exposed for one week to natural pH (8.1) and two reduced pH values (pH −0.4 units and pH −0.7 units). Exposure continued for additional two weeks, both in the absence and in the presence of environmentally relevant concentrations of caffeine (0.05 and 0.5 µg/L). Hemocyte parameters (total hemocyte count, hemocyte volume and diameter, neutral red uptake and hemocyte proliferation) were measured after 7 days of exposure to pH only, and after 14 (T1) and 21 (T2) days of exposure to the various pH*caffeine combinations. At all sampling times, pH significantly affected all the biological variables considered, whereas caffeine exhibited a significant influence at T2 only. Among the various hemocyte parameters, caffeine caused a significant increase in total hemocyte count at T2, and in hemocyte volume and diameter at both T1 and T2, when a significant interaction between pH and caffeine was also found. Overall, results demonstrated that hemocyte functionality was strongly influenced by the experimental conditions tested. Further studies are needed to assess combined effects of climate changes and emerging contaminants on bivalve immune system when challenged with environmental pathogens.

Effect of Chromolaena odorata as bioactive compound in artificial diet on survival rate of tiger prawn Penaeus monodon

The leaves of Chromolaena odorata can be used as alternative bioactive compounds to address high mortality in shrimp due to outbreaks of Vibrio sp. during both larval rearing and grow-out. The study aimed to determine the effect of Chromolaena odorata leaves on the survival and growth performance of tiger prawn Penaeus monodon larvae. Four different formulated diets with different concentrations of Chromolaena odorata leaves (1250 mg/kg, 1500 mg/kg, 1750 mg/kg) and a control (0 mg/kg) were fed to tiger prawns infected with Vibrio harveyi. Data were collected on total hemocyte count (THC), phenoloxidase (PO) and survival rate. One way ANOVA was applied for statistical analysis. The results show that Chromolaena odorata leaves were able to increase the immune response of tiger prawns infected with Vibrio harveyi. This was indicated by the increase in total haemocyte count (THC), phenoloxidase (PO) and survival rate with the values of 0.05 × 106 cells / mL, 0.05 and 84 %, respectively, for the formulated diet treatment with 1500 mg/kg feed. The increase in tiger prawn immune response led to increased resilience against Vibrio harveyi. As a result, survival rates of treated tiger prawns were higher than the control.

Comparative analysis of immune responses in Colorado potato beetle larvae during development of mycoses caused by Metarhizium robertsii, M. brunneum, and M. pemphigi

A comparative investigation of humoral and cellular immune response in larvae of Colorado potato beetle Leptinotarsa decemlineata was conducted under development of mycoses caused by entomopatho- genic fungi Metarhizium robertsii, M. brunneum and M. pemphigi. The larvae were found highly suscep- tible to M. robertsii, M. brunneum and less susceptible to M. pemphigi. The susceptibility to the fungi was not correlated with the rate of conidia germination in epicuticular extracts of larvae. A non-specific for Colorado beetle pathogen M. pemphigi did not cause significant changes in the immune response and did not result in colonization of larvae hemocoel. Infection with M. robertsi and M. brunneum led to an increase in total hemocyte count at the initial stages of mycoses (day 2) followed by a sharp decrease on day 3. The strongest decrease was observed for the immunocompetent cells - plasmatocytes and granu- locytes. Enhanced phenoloxidase activity in hemolymph and cuticle was found on days 2 and 3 after in- fection. These changes in immune reactions correlated with the level of virulence of the strains. Thus, the immune response in Colorado potato beetle larvae is an important factor determining differences in the development of mycoses caused by different Metarhizium species.

Galleria mellonella larvae are capable of sensing the extent of priming agent and mounting proportionatal cellular and humoral immune responses

Larvae of Galleria mellonella are useful models for studying the innate immunity of invertebrates or for evaluating the virulence of microbial pathogens. In this work, we demonstrated that prior exposure of G. mellonella larvae to high doses (1×104, 1×105 or 1×106 cells/larva) of heat-killed Photorhabdus luminescens TT01 increases the resistance of larvae to a lethal dose (50 cells/larva) of viable P. luminescens TT01 infection administered 48h later. We also found that the changes in immune protection level were highly correlated to the changes in levels of cellular and humoral immune parameters when priming the larvae with different doses of heat-killed P. luminescens TT01. Priming the larvae with high doses of heat-killed P. luminescens TT01 resulted in significant increases in the hemocytes activities of phagocytosis and encapsulation. High doses of heat-killed P. luminescens TT01 also induced an increase in total hemocyte count and a reduction in bacterial density within the larval hemocoel. Quantitative real-time PCR analysis showed that genes coding for cecropin and gallerimycin and galiomycin increased in expression after priming G. mellonella with heat-killed P. luminescens TT01. All the immune parameters changed in a dose-dependent manner. These results indicate that the insect immune system is capable of sensing the extent of priming agent and mounting a proportionate immune response.

Dietary supplement of banana (Musa acuminata) peels hot-water extract to enhance the growth, anti-hypothermal stress, immunity and disease resistance of the giant freshwater prawn, Macrobrachium rosenbergii

In the present study, Macrobrachium rosenbergii were fed with diets containing extracts of banana, Musa acuminate, fruit's peel (banana peels extract, BPE) at 0, 1.0, 3.0 and 6.0 g kg−1. The non-specific immune parameters, disease resistance and anti-hypothermal stress were evaluated at 2, 4, 8, 16 and 32 days of post feeding. Also, we demonstrated the percent weight gain (PWG), percent length gain (PLG), feeding efficiency (FE), and survival rate of giant freshwater prawn at 30, 60, 90, and 120 days of post feeding. The PWG, PLG, FE and survival rate of prawns fed at 0, 1.0, 3.0 and 6.0 g kg−1 BPE-containing diets after 120 days were 69.5%, 75.4%, 77.8% and 83.3%; 21.8%, 23.6%, 27.8% and 33.9%; 0.60, 0.72, 0.75 and 0.90; and 55.4%, 62.2%, 62.3% and 75.3%, respectively. After 32 days of post feeding, a significant increase in total haemocyte count (THC), different haemocyte count (DHC), respiratory bursts (RBs), superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, phenoloxidase (PO) activity and transglutaminase (TG) activity, and meanwhile, a decreased haemolymph coagulation time was observed. Furthermore, phagocytic activity and clearance efficiency of prawns against Lactococcus garvieae infection were significantly increased. Prawns challenged with L. garvieae after 32 days of feeding at 1.0, 3.0 and 6.0 g kg−1 had a significantly higher survival rate (33.3%, 40.0% and 56.7%) than those fed with the control diet. Subsequently, hypothermal (14 °C) stress was 43.4%, 50.0% and 50.0%, respectively. Altogether, we therefore recommend the dietary BPE administration at 6.0 g kg−1 promotes growth, anti-hypothermal stress, and enhance immunity and resistance against L. garvieae in M. rosenbergii.

Genotoxicity monitoring of freshwater environments using caged crayfish (Astacus leptodactylus)

Genotoxicity of freshwater pollution was assessed by measuring DNA damage in haemocytes of caged freshwater crayfish Astacus leptodactylus by the means of Comet assay and micronucleus test, integrated with the measurements of physiological (total protein concentration) and immunological (total haemocyte count) haemolymph parameters as biomarkers of undergone stress. Crayfish were collected at the reference site (River Mrežnica) and exposed in cages for 1week at three polluted sites along the Sava River (Zagreb, Sisak, Krapje). The long term pollution status of these locations was confirmed by chemical analyses of sediments. Statistically significant increase in DNA damage measured by the Comet assay was observed at all three polluted sites comparing to the crayfish from reference site. In addition, native crayfish from the mildly polluted site (Krapje) cage-exposed on another polluted site (Zagreb) showed lower DNA damage than crayfish from the reference site exposed at the same location indicating adaptation and acclimatisation of crayfish to lower levels of pollution. Micronuclei induction showed similar gradient of DNA damage as Comet assay, but did not reach the statistical significance. Observed increase in total haemocyte count and total protein content in crayfish from polluted environments in the Sava River also confirmed stress caused by exposure to pollution. The results of this study have proved the applicability of caging exposure of freshwater crayfish A. leptodactylus in environmental genotoxicity monitoring using Comet assay and micronucleus test.

The immune response of the desert locust Schistocerca gregaria during mycosis of the entomopathogenic fungus, Metarhizium anisopliae var acridum

Topical application of Metarhizium anisopliae var acridum to the desert locust Schistocerca gregaria resulted in changes in the biochemistry and antimicrobial defenses of the haemolymph. M. anisopliae var acridum colonized the host haemolymph from day two post application. The haemocytes did not attach to, phagocytose or nodulate elements of the fungus. However, the presence of the fungus appeared to stimulate hemocyte aggregation over the first few days of mycosis though the number of aggregates declined subsequently. The total hemocyte count increased two days after application, indicating an overall stimulation of the immune system, but declined to a value below that for uninoculated controls by day four. The differential haemocyte count showed that the initial increase in total haemocyte count was primarily due to a larger number of coagulocytes. After day two consistent declines in cell number were observed for all haemocyte classes in mycosed insects. The activity of the enzyme, phenoloxidase, decreased during the course of infection. However, the converse was true for prophenoloxidase. Lysozyme levels were significantly smaller in infected than control locusts. There was a significant correlation between lysozyme and PO activities when data from mycosed and control insects were combined. The total protein content of the haemolymph decreased during the course of infection.

Effect of hormones on total haemocyte count during the post-embryonic development of Corcyra cephalonica (Lepidoptera)

Total haemocyte count increased gradually from the penultimate instar to late last instar larvae of Corcyra cephalonica. However, the cell number declined during prepupal stages. Decapitation and ligation behind the thoracic segments resulted in a decrease of the haemocyte number in the posterior part of the larvae. Injection of brain homogenate either from early last instar larvae of C. cephalonica or nymphs of Periplaneta americana into decapitated larvae, caused a significant increase in total haemocyte count. Injection of 5 μg of 20-hydroxyecdysone into the posterior half of thorax ligated larvae caused a significant increase in total haemocyte count, while application of juvenile hormone-I alone had no effect. However, juvenile hormone-I, when applied in conjunction with 20-hydroxyecdysone partially blocked the effect of 20-hydroxyecdysone.