ABSTRACT
Hematological studies are valuable diagnostic techniques in the medical care of fish, reflecting the health condition and the effects of environmental factors on fish. Due to the high value of sturgeon fish and necessity to recover the brood stock, this study was done to provide data about hematological parameters and reproduction normative of wild brood stock beluga, Huso huso, from the southeast of the Caspian Sea. Hematological parameters including RBC, WBC, hematocrit, hemoglobin, MCV, MCH, MCHC, and differential leukocyte count were determined. In this regard, 7 male and 7 female wild broods were studied. Differences in mentioned parameters between genders were evaluated. The correlations among parameters were also determined. According to the results, the male fish had significantly higher WBC and lymphocyte and lower neutrophil compared to the females. Also, functional fecundity was 447000 +/- 157210 and weight of extracted oocytes was 35.4 +/- 3.78 mg/ cell. The oocytes' long diameter was 4.17 +/- 0.21mm and width diameter was 3.75 +/- 0.19 mm. Egg fertilization rate was 46.7 +/- 24.33%, and larvae weight was 25.48 +/- 1.56 mg. Hematological parameters of juvenile and fingerling reared beluga showed wide ranges, and there are differences in hematological parameters between reared and wild broodstock belugas. These findings highlight the importance of hematological study in wild beluga sturgeon
ABSTRACT
Streptococcosis caused by Streptococcus iniae is one the most important bacterial diseases in aquaculture industry worldwide. This study was aimed to assess the experimental pathogenicity of Streptococcus iniae in Persian sturgeon [Acipenser persicus] fingerling. A number of 400 Persian sturgeon [Acipenser persicus] fingerling weighting 17 +/- 3 g were used. Fish were challenged with a virulent strain of Streptococcus iniae via both intraperitoneal and intramuscular injections at dosage of 4.7×106, 4.7×105, 4.7×104, 4.7×103, 4.7×102 cells/fish. Each treatment group included 12 fish in two replicates. Control fish received 0.1 mL per fish sterile normal saline [0.9% NaCl]. Clinically mortality started after 24 hours post-challenge and the affected fish showed listless, spiral swimming, spot haemorrhages on different parts of bodies particularly at the base of fins, the lateral line around the bone columns, on the base of barbells, mouth and around anal area. Also signs of abdominal distention, hyperemia of intestine, accumulation of bloody fluid in abdominal cavity, lordosis and scoliosis as well as hemorrhages in eyes were seen. The lethal concentration [LD50] of intraperitoneal injection was calculated 1.1×103, 8×103, 3.7×106 cells/fish after 48, 72 and 96 hours post-challenge, respectively. The LD50 of intramuscular injection was 4.8×102, 1.8×103 and 6.4×105 cells/fish at 48, 72 and 96 hours post-challenge, respectively [p<0.05]. No mortality or abnormal signs was seen in control fish up to 14 days post-experiment. The results of this study showed that Parisian sturgeon fingerling is highly susceptible to Streptococcosis
Subject(s)
Animals , Fishes/microbiologyABSTRACT
Various studies have been conducted to show the effects of essences and enzymes on foodborne pathogens in culture media. The aim of this study was to determine the effect of Zataria multiflora Boiss. essential oil and lysozyme alone and in combination on preventing growth of Vibrio parahaemolyticus in culture media. In this study, the MIC of Zataria multiflora Boiss. essential oil and lysozyme, together and alone, on Vibrio parahaemolyticus, was determined by using macro and microdilution methods. The MIC of Zataria multiflora essential oil determined 0.01% and 0.02% by using macro and microdilution methods, respectively and lysozyme at 1000 mg/mL concentration could not inhibit the growth of V. parahaemolyticus. According to the results of current study, Zataria multiflora essential oil showed better results in comparison with lysozyme, moreover Applying lysozyme and essential oil together did not decrease MIC, but extended the latent phase of V. parahaemolyticus, which considered an important factor in microbiology
ABSTRACT
Vibrio parahaemolyticus causes acute gastroenteritis associated with the consumption of contaminated raw or under cooked seafood. The virulence of vibrio parahaemolyticus is initially attributed to the production of a thermostable direct hemolysin [TDH]. The survey of different concentrations of garlic essential oil [Allium sativum] on MIC, MBC, growth curve and production of TDH toxin of vibrio parahaemolyticus. The effects of garlic essential oil at concentrations of 0, 0.005, 0.015, 0.03 and 0.045% on the MIC, MBC, growth curve and production of TDH toxin of vibrio parahaemolyticus were studied in BHI model. MIC and MBC of garlic essential oil was estimated 0.03%. The essential oil showed significant effect on toxin production, Titers of TDH production in 0 and 0.005% were 1/256 comparing to 1.64 in 0.015% concentration of EO. Concentrations of 0.005 and 0.015% of garlic essential oil reduced the bacterial growth rate significantly [p<0.05] compared to the control group. Garlic essential oil showed to be effective against bacterial growth and production of TDH toxin. Its potential application in food systems may be suggested
ABSTRACT
Zataria multiflora Boiss. is one of the Iranian traditional spices and it has antimicrobial effect on the pathogenic bacteria which are agents for some current foodborne intoxications. The present study was conducted to evaluate the antimicrobial activity of Zataria multiflora Boiss. Essential oil on Escherichia coil 0157:H7. Minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] of Zataria multiflora Boiss. Essential oil [EO] for Escherichia coil 0157:H7 at 35°C, the effect of subinhibitory concentrations of EO on growth curve of bacteria up to 24 hours at 25 and 35°C and also production of shigatoxin 2 [Stx2], at 35°C has been determined. MIC and MBC of EO which have been evaluated were 0.04 and 0.06%, respectively the effect of subinhibitory concentrations of EO on bacterial growth curve during 24 hours has been determined by spectrophotometer device at 25 and 35°C and also production of shigatoxin 2 [Stx2], at 35°C has been determined. Subihibitory concentrations of EO, significantly, decreased the production of Stx2 at 35°C in a dose dependent manner. The results showed that Zataria multiflora Boiss. Essential oil had inhibitory effect on Escherichia coli 0157:H7 and it can be used as a natural preservative in food industry