Effects of Dietary Lactic Acid Supplementation on the Activity of Digestive and Antioxidant Enzymes, Gene Expressions, and Bacterial Communities in the Intestine of Common Carp, Cyprinus carpio

The present study investigated the effects of dietary lactic acid (LA) supplementation on the growth performance, intestinal digestive/antioxidant enzymes' activities, gene expression, and bacterial communities in common carp, Cyprinus carpio. Four diets were formulated to contain 0 g/kg LA (control), at 2.5 g/kg LA (2.5LAC), 5 g/kg LA (5LAC), and 10 g/kg LA (10LAC) and offered to the fish over a period of 56 days. The results showed that dietary 5 g/kg LA supplementation improved growth performance and feed efficiency in the fish. All LA treatments exhibited significant elevations in the intestinal trypsin and chymotrypsin activities, whereas the intestinal lipase, amylase, and alkaline phosphatase activities exhibited significant elevations in the 5LAC and 10LAC treatments. All LA treatments exhibited significant elevations in the intestinal heat shock protein 70, tumor necrosis factor-alpha, interleukin-1 beta, and defensin gene expressions, and the highest expression was observed in the 5LAC treatment. Additionally, dietary LA treatment significantly increased the lysozyme expression and Lactobacillus sp. population in the intestine of the fish, and the highest values were observed in the 5LAC and 10LAC treatments. Aeromonas sp. and Vibrio sp. populations decreased in the LA treatments, and the lowest Aeromonas sp. population was observed in the 10LAC treatment. The intestinal mucin2 and mucin5 expressions, and the hepatic reduced glutathione content, significantly increased, whereas hepatic glutathione peroxidase, glutathione reductase, and malondialdehyde significantly decreased in the 5LAC and 10LAC treatments. In conclusion, dietary 5 g/kg LA is recommended for common carp feeding to improve growth rate, antioxidant capacity, and intestinal health.

Parasitic fauna of farmed freshwater ornamental sutchi catfish (Pangasiandon hypophthalmus) and silver dollar (Metynnis hypsauchen) in Alborz province, Iran

BACKGROUND

Parasitic infestations are one of the most significant problems in global aquaculture. In addition to direct economic losses due to significant mortalities, parasites may have a significant negative impact on the fish's behaviour, energetic demands, trophic position, interspecific competition, growth rate, and reproductive function.

OBJECTIVES

We conducted the present study to evaluate the infection status of parasitic pathogens in freshwater sutchi catfish (Pangasianodon hypophthalmus) and silver dollar (Metynnis hypsauchen) farmed in Alborz province of Iran.

METHODS

Between January and February 2021, 140 ornamental fish, including 70 sutchi catfish (P. hypophthalmus) and 70 silver dollar (M. hypsauchen), were delivered from various ornamental fish farms for parasitological analysis. Thorough macroscopic and microscopic examinations were performed to detect parasitic infections in delivered freshwater ornamental fish.

RESULTS

A total of six parasite species, including five protozoan species (Nyctotherus piscicola, Trichodina heterodentata, Ichthyophthirius multifiliis, Protoopalina sp., and Hexamita sp.) and one monogenean species (Ancyrocephalus sp.), were identified in the examined fish. The overall prevalence of the recovered parasites was 46.43% (65/140) of the fish.

CONCLUSIONS

In the current study, several parasites, including Hexamita sp., Ancyrocephalus sp., Protoopalina sp., and N. piscicola, were identified as the first records of the sutchi catfish (P. hypophthalmus) and/or silver dollar (M. hypsauchen), and these two fish species are known as new hosts for the isolated parasites in ornamental fish farms in Iran. Assessing the parasitic fauna of ornamental fish is therefore critical for preventing parasite introduction into adjacent provinces as well as neighbouring countries and promoting fish health.

Effects of Dietary Glycine Supplementation on Growth Performance, Immunological, and Erythrocyte Antioxidant Parameters in Common Carp, Cyprinus carpio

The effects of dietary glycine supplementation, 0 (control), 5 (5 GL), and 10 (10 GL) g/kg, have been investigated on growth performance, hematological parameters, erythrocyte antioxidant capacity, humoral and mucosal immunity in common carp, Cyprinus carpio. After eight weeks feeding, the 5 GL treatment exhibited significant improvement in growth performance and feed efficacy, compared to the control treatment. Red blood cell (RBC) and white blood cell (WBC) counts, hemoglobin, hematocrit, neutrophil and monocyte counts/percentages, RBC reduced glutathione (GSH) content, and skin mucosal alkaline phosphatase, peroxidase, protease, and lysozyme activities were similar in the glycine-treated fish and significantly higher than the control treatment. Blood lymphocyte percentage decreased in the glycine-treated fish, but lymphocyte count increased, compared to the control fish. RBC glutathione reductase activities in the glycine-treated fish were similar and significantly lower than the control treatment. The highest plasma lysozyme and alternative complement activities were observed in GL treatment. The glycine-treated fish, particularly 5 GL, exhibited significant improvement in RBC osmotic fragility resistance. Dietary glycine had no significant effects on RBC glutathione peroxidase activity, plasma immunoglobulin, eosinophil percentage/count, and hematological indices. In conclusion, most of the benefits of dietary glycine supplementation may be mediated by increased glutathione synthesis and antioxidant power.

Effects of Spirulina platensis on Iron Oxide Nanoparticles Induced-oxidative Stress and Liver Damage in Grey Mullet (Mugil cephalus)

Background: Nanoparticles are increasingly exposed to ecosystems and people due to their large-scale manufacture and usage. The use of nanomaterials has increased their discharge into the aquatic environment. Objectives: This research evaluated the protective effect of Spirulina platensis against liver damage and oxidative stress in grey mullet (Mugil cephalus) after exposure to Iron oxide nanoparticles. Methods: Juvenile grey mullets were randomly classified into 12 equal groups: Group 0, 96h control group; Group 1, 60 days control group; Group 2, iron oxide nanoparticles (IONPs) at 15mg/kg for 96h; Group 3, IONPs at 15mg/kg for 60 days; Group 4, S. platensis at 300mg/kg for 96h; Group 5, S. platensis at 300mg/kg for 60 days, Group 6, IONPs at 15mg/kg+S. platensis at 300mg/kg for 96h; Group 7, IONPs at 15mg/kg+S. platensis at 300mg/kg for 60 days; Group 8, IONPs at 15mg/kg (for 2 weeks) followed by S. platensis at 300mg/kg for 96h; Group 9, IONPs at 15mg/kg (for 2 weeks) followed by S. platensis at 300mg/kg for 60 days; Group 10, S. platensis at 300mg/kg (for 2 weeks) followed by IONPs at 15mg/kg for 96h; Group 11, S. platensis at 300mg/kg (for 2 weeks) followed by IONPs at 15mg/kg for 60 days. At the end of the experiment, samples of the liver were extracted and subjected to analyses to measure reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) Results: MDA levels in the liver were shown to have dramatically risen in the current investigation, but antioxidant SOD and GSH activity in the IONPs-treated group had significantly reduced compared to the controls. When compared to fish solely treated with IONPs, S. platensis treatment dramatically reduced liver MDA and CAT activity and raised SOD and GSH. Conclusion: All prior metrics significantly improved when IONPs-induced liver damage in fish was prevented by spirulina. By scavenging free radicals, reducing inflammation, and restoring endogenous antioxidant defense systems, S. platensis therapy has a protective effect in the liver of grey mullet against damage and oxidative stress in the IONPs.

Anesthesia of rainbow trout with citronellal: Efficacy and biochemical effects

The aim of this study was to assess the anesthetic efficacy and biochemical effects of citronellal on rainbow trout, Oncorhynchus mykiss. The fish were exposed to 200-800 µl/L citronellal to find the anesthesia induction and recovery times. The deep anesthesia stage was reached within 117-613 s, using 800-200 µl/L citronellal, respectively, and all fish recovered within 240-420 s. To assess biochemical responses, the fish were exposed to 200, 400, 600, and 800 µl/L of citronellal and blood-sampled after deep anesthesia. The results showed that anesthesia led to significant elevations in blood erythrocytes, hematocrit, hemoglobin, mean corpuscular volume, plasma lactate, and lactate dehydrogenase; these parameters exhibited increasing trends as citronellal concentration increased. These results along with significantly higher plasma lysozyme activity, cortisol, and glucose levels in 200 µl/L treatment suggest that an increase in citronellal concentration significantly mitigates hypoxia/stress responses in the fish. Significant elevations in plasma alkaline phosphatase activity and malondialdehyde level were observed in the 200 µl/L treatment, which suggests induction of hemolysis and oxidative stress in this treatment. There was a tendency to higher ammonia levels along with the increase in citronellal concentration, which might be due to early ammonia accumulation because of lower opercular movement in the fish. Except for blood hematocrit and mean corpuscular volume, there were no significant differences between the 600 and 800 µl/L citronellal treatments. In conclusion, high concentrations of citronellal are more suitable for trout anesthesia and blood sampling than low concentrations. Based on the present study, 600-800 µl/L citronellal is recommended for trout anesthesia.

Food sources for camptandriid crabs in an arid mangrove ecosystem of the Persian Gulf: a stable isotope approach

Crabs of the family Camptandriidae are the most dominant burrowing crabs inhabiting arid mangrove forests of the Persian Gulf. They play important roles in the structuring and functioning of mangrove ecosystems by modulating biogeochemical processes and cycling of nutrients, serving as important ecosystem engineers. We analysed stable carbon (¹³C) and nitrogen (¹⁵N) isotope values of three camptandriid crabs (Opusia indica, Nasima dotilliformis, and Manningis arabicum) and their potential food sources in the Hara Biosphere Reserve, northern Persian Gulf. A Bayesian mixing model was used to estimate the contribution of potential food sources for consumers. The results showed that to some degree, all the four sources selected contributed to the camptandriid diets, but microphytobenthos made the most important contributions to the diet of the consumers. Mangroves do not appear to be a significant source of carbon in the diet of camptandriid crabs in the arid mangrove system of the Persian Gulf. Rather, they offer favourable growing conditions, thus boosting microphytobenthos production and availability for consumers which prefer a high nutritional and palatable source.

Effects of dietary thyme (Zataria multiflora) extract on antioxidant and immunological responses and immune-related gene expression of rainbow trout (Oncorhynchus mykiss) juveniles

Effects of dietary hydroalcoholic extract of Zataria multiflora (ZE) on growth performance, plasma and hepatic antioxidant capacities, and humoral and skin mucus immune parameters were evaluated in rainbow trout (Oncorhynchus mykiss) juveniles. in vitro tests showed that ZE had antioxidant property comparable to butylated hydroxytoluene (BHT) at 100-200 μg/mL concentrations, although its antioxidant property was lower than BHT at concentration below 100 μg/mL. Moreover, ZE had anti-bacterial activity against Aeromonas hydrophila, which was 30-50% lower than that of tetracycline. After feeding the fish with diets supplemented with 0 (CT, 1 (ZE1), 2 (ZE2), and 3 (ZE3) g/kg ZE for eight weeks, there were no significant differences in growth performance and feed efficiency among the treatments; however, the fish in ZE2 and ZE3 treatments showed significantly higher survival than the fish in CT treatment. Blood leukocyte counts, plasma globulin, total immunoglobulin, lysozyme and bactericidal activity against A. hydrophila in ZE2 and ZE3 groups were significantly higher than that of CT group. All the ZE-treated groups had higher plasma complement activity compared to the CT group. Mucosal lysozyme and bactericidal activities of the ZE2 fish were significantly higher than the other treatments. Expression of tumor necrosis factor alpha, interleukin-1 beta, interleukin-6, and lysozyme genes increased in head kidney of the fish treated with ZE; the highest increases were related to the ZE2 treatment. Plasma total antioxidant (TA) activities of ZE2 and ZE3 treatments were significantly higher than that of the CT treatment. Plasma and hepatic superoxide dismutase (SOD) and catalase (CAT) activities of ZE2 group were significantly higher than the other treatments. Plasma malondialdehyde (MDA) levels were significantly lower in ZE2 treatment, compared to the other treatments. However, hepatic MDA level of ZE2 treatment was significantly lower than those of the ZE1 and CT treatments. In conclusion, dietary ZE supplementation level of 2 g/kg is suggested for rainbow trout feed supplementation to augment fish survival, antioxidant and immune strength.

Humoral immune responses and gill antioxidant-related gene expression of common carp (Cyprinus carpio) exposed to lufenuron and flonicamide

The aim of this study was to investigate plasma proteins, total immunoglobulin (Ig), lysozyme and complement (ACH50) levels, and gill superoxide dismutase (SOD) and catalase (CAT) gene expression in common carp (Cyprinus carpio), following exposure to lufenuron (LUF) and flonicamide (FL). Fish were distributed in 12 tanks as three quadrupled treatments: control (fish were kept in pesticide-free water), LUF [fish exposed to 10% of LUF LC50 (4.3 mg/L)], and FL [fish exposed to 10% of FL LC50 (0.1 mg/L)]. The plasma parameters were assessed after 7 and 21 days exposure to pesticides, whereas the gene expressions were assessed after 21 days. The results showed that LUF exposure significantly decreased plasma total protein and globulin levels compared to the control group. Both pesticide significantly decreased plasma total Ig levels compared to the control group; however, LUF exhibited a greater effect. There were no significant effects of pesticides or sampling time on plasma ACH50 activity. Pesticides and sampling time interacted to affect plasma lysozyme activity. Seven days after exposure, both pesticides significantly increased lysozyme activity, and the effect of FL was greater than LUF. Nevertheless, there was no significant difference in plasma lysozyme activities among the pesticides, 21 days after the exposure. Both pesticides significantly decreased SOD and CAT gene expression, nevertheless, FL exhibited greater effects than LUF. In conclusion, both pesticides induced immunosuppression in the fish, though such effects were more severe in LUF group, compared to the FL. These pesticides negatively affect expression of gill antioxidant genes, and the FL effects were greater than the LUF.

LC50 determination and intoxication symptoms of a new pyridine carboxamide pesticide Flonicamid on common carp Cyprinus carpio

The present study was undertaken to evaluate the lethal toxicity and stress signs of Flonicamid toward juvenile common carp ( Cyprinus carpio ). The 96 h LC50 values, determined 43.17 mgL-1 by probit analysis in a semi-static system. LC50 24, 48 and 72 h were 47.54, 41.83 and 43.51 mgL-1, respectively. Behavioral changes include hyperexcitement, erratic swimming, dark coloration, loss of equilibrium and lethargy were observed with different intensities. Consequently, mortality rate, stress signs and behavioral changes observed in response to the Flonicamid are dependent to dose and time exposure.

Dietary sodium butyrate (Butirex® C4) supplementation modulates intestinal transcriptomic responses and augments disease resistance of rainbow trout (Oncorhynchus mykiss)

Intestine in fish is a complex multifunctional organ, not only plays roles in digestion and absorption of nutrient, but also has critical role in immunity. The present study evaluated the effects of different levels of dietary sodium butyrate [Butirex^® C4 (Butirex)] on intestinal immune-,antioxidant-and tight junction-related gene expression injuvenile rainbow trout(Oncorhynchusmykiss). 240 healthy rainbow trout were dispensed in 12 fiberglass tanks appointed to four treatments [0 (control), 1.5 (B1.5), 2.5 (B2.5) and 5 (B5)g Butirex per kg diet]. After a 45-day feeding trial, the fish fed with the Butirex-supplemented diets showed higher intestinal lysozyme (LYZ), complement(ACH50) and bactericidal activities; the elevations in ACH50 and bactericidal activities depended on Butirex levels (P < 0.05). The Butirex-supplemented groups, particularly the B2.5 group, had significantly higher LYZ gene expression compared to the control group (P < 0.05). Butirex at 2.5 and 5 g/kg levels led to significantly higher IL-1β gene expression. B2.5 and B5 had significantly lower and higher TNF-α gene expression compared to the control group (P < 0.05). The B2.5 group had significantly higher TGF-B, and significantly lower IL-8 compared to the control group (P < 0.05). The B1.5 and B2.5 group had significantly higher IL-10 gene expression compared to the control group (P < 0.05). The B2.5 and B5 groups had significantly higher SOD gene expression compared to the other groups; the highest expression was related to the B2.5 group (P < 0.05). Dietary Butirex supplementation significantly up-regulated CAT and GPx genes expression compared to the control group; the highest expression as related to the B2.5 and B5 groups (P < 0.05). The B2.5 group had significantly lower CLD12 gene expression compared to the control group (P < 0.05). The B2.5 and B5 groups had significantly higher CLD3, OCLD and ZO-1 gene expression compared to the control. The highest CLD3, ZO-1 gene expressions was related to the B2.5, and B5 groups respectively (P < 0.05). After challenge with Streptococcus iniae, B2.5 and B5 had significantly higher survival compared to the control group (55.6 ± 7.70 and 68.9 ± 10.2 vs. 33.3 ± 6.67). In conclusion, Butirex is efficient immune stimulant and health booster in rainbow trout, which augments the fish resistance to disease. Modulation of immune components, cytokines, antioxidant system and intestinal integrity might involve in improving disease resistance in Butirex-treated fish. Although most of the examined genes were modulated by 2.5 g/kg Butirex under normal conditions, 5 g/kg level is recommended under pathogenic state to mitigate mortality.

Expression of immune, antioxidant and stress related genes in different organs of common carp exposed to indoxacarb

The aim of the present study was to investigate the effects of chronic exposure of common carp (Cyprinus carpio) to indoxacarb on immune, antioxidant and stress gene expression. After 21 days exposure to 0, 0.75, 1.5 and 3 ppm indoxacarb, expression of IL-1β, IL-8, IL-10, TNF-α, IFN-γ, SOD, CAT, HSP70, IGF-I and IGF-II were assessed in liver, kidney and gills. In general, exposure to low concentration of indoxacarb increased inflammatory cytokine gene expression (IL-1β, IL-8, IL-10, TNF-α and IFN-γ) and inhibits inflammatory cytokines' expression at higher concentrations. The assessment of antioxidant gene expression (SOD and CAT) in different organs indicate that they were increased by low concentrations of indoxacarb to deal with primary oxidative situation. However, higher concentrations of indoxacarb caused reduction in oxidative gene expression. IGF genes expression in liver significantly increased at a concentration of 0.75 ppm treatment, then it decreased at 1.5 ppm indoxacarb and increased again by increasing in the indoxacarb concentration to 3 ppm. The expression of HSP70 in kidney showed a significant elevation in 0.75 and 1.5 ppm treatments compared with 3 ppm treatment and the control group. The expression of this gene in liver was significantly increased in 1.5 and 3 ppm treatments. The same pattern of expression was also observed in gill. Overall, indoxacarb exposure affects common carp health at transcription levels. Changes in the genes expression generally suggest that indoxacarb exposure led to interference in inflammation, oxidative stress and tissue damage.

Effects of dietary 1,8-cineole supplementation on physiological, immunological and antioxidant responses to crowding stress in rainbow trout (Oncorhynchus mykiss)

The aim of the present study was to investigate beneficial effects of dietary 1,8-cineole (cineole) supplementation on physiological, immunological and antioxidant responses of rainbow trout (Oncorhynchus mykiss) to crowding stress. The fish were fed for 50 days with diets containing 0 (control), 0.05, 0.1, 0.25, 0.5 and 1% cineole prior to exposure to a 14-day crowding stress. Serum stress markers (cortisol, glucose, lactate, T₄ and T₃), antioxidant responses [catalase (CAT) and superoxide dismutase (SOD) activities and total antioxidant capacity (TAC) and malondyaldehyde (MDA) levels] and immune responses [lysozyme and alternative complement (ACH50) activity, and total immunoglobulin (Ig) levels], and blood leukocyte (WBC) and differential counts were measured before and after crowding stress. Results showed that 1% cineole was capable to reduce the basal and stress-induced cortisol elevation and increase the serum T₃ levels after stress. Increase in dietary cineole levels significantly decreased serum cortisol, glucose and lactate levels. Increase in dietary cineole levels significantly increased serum CAT, SOD, lysozyme and ACH50 activities, and TAC and eosinophil levels, and decreased MDA and monocyte levels. After the stress, there was no significant difference in the control group CAT and SOD activities compared to the basal values; however, CAT activities decreased and SOD activities increased in the cineole-treated groups compared to the basal values. Nevertheless, the control group had significantly lower CAT and SOD activities compared to the fish treated with 0.1-1% cineole. Cineole significantly increased blood WBC and serum lysozyme, ACH50 and total Ig. Moreover, cineole administration significantly mitigated the stress-induced decrease in total Ig levels as well as increase in leukocyte count. The cineole-treated fish had higher survival and growth performance compared to the control group. Although all levels of cineole (0.05-1%) showed beneficial effects on different tested factors, 0.5 and 1% levels had beneficial effects on most of the tested factors; thus, are recommended for dietary inclusion to suppress adverse effects of stress in trout.

Rainbow trout (Oncorhynchus mykiss) anesthesia with myrcene: efficacy and physiological responses in comparison with eugenol

The aim of the present study was to investigate anesthetic efficacy of myrcene in rainbow trout (Oncorhynchus mykiss) along with the fish biochemical response to anesthesia in comparison with eugenol. In the first experiment, 240 fish were stocked in 12 tanks and acclimatized to experimental conditions for 2 weeks. Then, the fish of each tank were subjected to one concentration of either eugenol (12, 20, 30, 50, 80, and 130 μL/L) or myrcene (100, 150, 200, 300, 400, and 500 μL/L) concentrations. Induction time of and recovery time from anesthesia were recorded for each fish separately. Using these results, desired concentrations to induce anesthesia within 60, 180, 300, and 600 s were determined, being 81, 30, 19, and 10 μL/L eugenol and 531, 251, 177, and 111 μL/L myrcene. In the second experiment, 96 fish were stocked in 8 tanks. Six fish were netted from each tank and exposed to the calculated eugenol or myrcene concentrations. Blood samples were taken after the fish reached anesthesia. The results showed that there was no significant difference in serum lactate, alanine transaminase, and alkaline phosphatase. Increase in the induction time of anesthesia resulted in increased serum glucose with no significant difference between the anesthetics. Increase in induction time of anesthesia led to increase in serum lactate dehydrogenase activity in the eugenol-anesthetized fish and aspartate transaminase activity in myrcene-anesthetized fish. In conclusion, myrcene is capable to anesthetize rainbow trout, but at higher concentrations compared to eugenol. In addition, biochemical analysis showed that increase in induction time of anesthesia leads to hyperglycemia and increase in AST and LDH activities depending on anesthetic type.

The effects singular or combined administration of fermentable fiber and probiotic on mucosal immune parameters, digestive enzyme activity, gut microbiota and growth performance of Caspian white fish (Rutilus frisii kutum) fingerlings

The aim of the present study was to investigate the effects of single or combined administration of dietary fermentable fiber (Vitacel^®) and probiotic PrimaLac^® on mucosal immune parameters, digestive enzyme activity, gut microbiota and growth performance of Caspian white fish (Rutilus frisii kutum) fingerlings. Fish were transferred to laboratory, acclimatized for two weeks and then fish (0.56 ± 0.026 g) were allocated into 12 tanks (30 fish per tank). Triplicate groups were fed a basal diet (Control) or basal diet supplemented with fermentable fiber [Vitacel^®] (FF), probiotic [PrimaLac^®] (P) and combined fermentable fiber and probiotic (FF + P). At the end of feeding trial, growth performance and feed utilization parameters were significantly (P < 0.05) improved in FF, P and FF + P treatments compared control group. Evaluation of digestive enzyme activity revealed significant (P < 0.05) increase of lipase activity in fish fed supplemented diet. However, amylase, protease and alkaline phosphatase were significantly higher (P < 0.05) only in P and FF + P treatments. Furthermore, total autochthonous intestinal microbiota and autochthonous LAB levels significantly increased in fish fed supplemented diet (P < 0.05). Also, inclusion of FF, P and FF + P in Caspian white fish diet remarkably increased skin mucus immune parameters compared control group (P < 0.05). These results indicate that singular or combined administration of FF and P can be considered as a beneficial dietary supplement for early stages of Caspian white fish (Rutilus fresii kutumn) culture.

Modification of saltwater stress response in Cyprinus carpio (Linnaeus, 1758) pre-exposed to pesticide indoxacarb

To evaluate the effects of indoxacarb on saltwater stress response in Cyprinus carpio, the fish were pre-exposed to indoxacarb (0, 0.75, 1.5 and 3mg/L denoted as CP, 0.75IT, 1.5IT and 3IT, respectively) for 21 days and then released to saltwater. A negative control (CN) group was included (the fish were held in indoxacarb-free water for the entire experiment). The fish were sampled immediately (0h) and 24, 48 and 72h after the salinity exposure for the analysis of plasma cortisol, glucose and sodium, chloride, potassium and calcium levels. All fish pre-exposed to 3mg/L indoxacarb, died after the first day of salinity challenge. CP showed typical cortisol response after the salinity challenge, but, cortisol response of the fish pre-exposed to indoxacarb (0.75IT and 1.5IT) was blocked. Plasma glucose increased significantly in all groups compared to the CN; however, this elevation had no consistent trend in 0.75IT and 1.5IT which indicated interference in glucose response due to indoxacarb exposure. Plasma sodium increased (compared to CN) in all groups after the salinity challenge. However, elevation in plasma chloride and potassium was significantly different among the groups and the indoxacarb-treated fish showed slightly sooner ionic disturbance. The results clearly indicate that indoxacarb impairs stress response of C. carpio and the fish may not be able to respond normally to additional stressors, which threatens their survival.

Dietary Immunogen® modulated digestive enzyme activity and immune gene expression in Litopenaeus vannamei post larvae

Pacific white shrimp Litopenaeus vannamei (Boone, 1931) is an important economical shrimp species worldwide, especially in the Middle East region, and farming activities of this species have been largely affected by diseases, mostly viral and bacterial diseases. Scientists have started to use prebiotics for bolstering the immune status of the animal. This study aimed to investigate the influence of Immunogen^® on growth, digestive enzyme activity and immune related gene expression of Litopenaeus vannamei post-larvae. All post-larvae were acclimated to the laboratory condition for 14 days. Upon acclimation, shrimps were fed on different levels of Immunogen^® (0, 0.5, 1 and 1.5 g kg^-1) for 60 days. No significant differences were detected in weight gain, specific growth rate (SGR) and food conversion ratio (FCR) in shrimp post-larvae in which fed with different levels of Immunogen^® and control diet. The results showed that digestive enzymes activity including protease and lipase increased with different amounts of Immunogen^® in the shrimp diet. Protease activity increased with 1.5 g kg^-1 Immunogen^® after 60 days and lipase activity increased with 1 and 1.5 g kg^-1 Immunogen^® after 30 and 60 days of the trial respectively (P < 0.05), while amylase activity did not change in response to different levels of Immunogen^® (P > 0.05). The expression of immune related genes including, prophenoloxidase, crustin and g-type lysozyme increased with diet 1.5 g kg^-1 Immunogen^® (P < 0.05) while expression of penaeidin gene increased only with experimental diet 1 g kg^-1 of Immunogen^®. These results indicated that increase in digestive enzymes activity and expression of immune related genes could modulate the Immunogen^® in the innate immune system in L. vannamei in this study.

Hemolysis interference in measuring fish plasma biochemical indicators

The present study aimed to determine hemolysis interference in measurement of plasma biochemical parameters in fish specimens. For this purpose, blood samples were harvested from 24 Huso huso juveniles. After centrifugation, each plasma sample was divided into seven portions to make seven levels of hemolysis. Hemolysis was induced by addition of different percentages of the corresponding whole blood [0 (non-hemolyzed control group), 1, 3, 5, 10, 15, and 20% of whole blood]. Albumin, total protein, calcium, phosphorus, glucose, sodium, potassium, chloride, alkaline phosphatase (ALP), aspartate transaminase (AST), and alanine transaminase (ALT) were measured in different samples. Results showed that plasma albumin, ALP, potassium, and AST significantly increased (more than 200% at the highest hemolysis level) in the hemolyzed samples. Also, plasma total protein and phosphorus showed significant elevation in the hemolyzed samples (more than 70% at the highest hemolysis level). Plasma glucose, calcium, chloride, and ALT showed narrow but significant increase in hemolyzed samples (11.8-35.2% at the highest hemolysis level). Plasma sodium showed no significant changes in the hemolyzed samples. In conclusion, the present results show that hemolysis markedly affects plasma parameters levels, which interferes with plasma results interpretation. Therefore, analysis of hemolyzed samples should be avoided or the results should be interpreted with caution. This study encourages further investigations to develop methods for omitting the effects of hemolysis by sample blanking and/or presenting correction coefficients for measurement of plasma parameters in samples with different levels of hemolysis.

Detection of Hepatitis C virus RNA in peripheral blood mononuclear cells of patients with abnormal alanine transaminase in Ahvaz

PURPOSE

Hepatitis C virus (HCV) is an important agent for chronic and acute hepatitis. Occult hepatitis C remains a major health problem worldwide. Patients with chronic occult HCV may progress to cirrhosis and hepatocellular carcinoma. The aim of this study was to determine prevalence of occult hepatitis C by IS-PCR-ISH (in situ PCR in situ hybridisation) in the patients with abnormal ALT.

MATERIALS AND METHODS

The blood samples were taken from 53 patients including 17 females (32.1%) and 36 (67.9%) males who had abnormal alanine transaminase (ALT) for more than 1 year. The mean ALT and aspartate transaminase (AST) level were 41.02±9.3 and 24.17±7.3, respectively. The patients' age were between 4 and 70-years old with mean age 38±13. All the patients were negative for HCV antibody, HCV RNA and HBs Ag. The peripheral blood mononuclear cells (PBMC) were separated with ficoll gradient from each blood sample, then the cells were fixed on slides by cold acetone and followed by IS-PCR-ISH for HCV RNA detection.

RESULTS

Seventeen (32%) patients including 6 (11.3%) females and 11 (20.7%) males showed positive results for HCV RNA by in situ-PCR in situ hybridisation. Ten (18.8%) positive cases were between 20 and 40-years old and 6 (11.3%) positive patients were between 40 and 60 years old. Ten (19.6%) patients who were positive for IS-PCR-ISH also had positive anti-HBc IgG and 7 (13.2%) patients were negative for HBc-IgG.

CONCLUSION

In the present study high rate of 32% occult hepatitis C were found among the patients with elevated ALT.