Study of efficacy of vaccination against yersinosis in rainbow trout using local strains of Yersinia ruckeri

Outbreak and development of yersiniosis in rainbow trout farms in Iran has caused a serious problem over the last years. The purpose of this study was to evaluate the efficacy of immersion vaccination with Yersinia ruckeri in rainbow trout. Prior to antigen preparation, the phenotypic, molecular and serological features of a number of Yersinia ruckeri isolates obtained from affected trout farms were studied. The virulent of these isolates were then evaluated using intra peritoneal injection route. Trout were vaccinated by immersion route [3 min at 12 °C] using Yersinia ruckeri bacterin of the virulent strains. The efficacy of vaccine antibody titer within 2, 4, 6, 8 and 10 weeks post vaccination were evaluated using relative percent survival. The phenotyping, serological and molecular studies have led to identification of 8 isolates of Yersinia ruckeri and all the isolates produced bands 409 bp, which is indicative of Yersinia ruckeri. In pathogenicity test 3 isolates caused above 50% mortality, while 5 isolates reached 16%. The RPS of vaccinated fish reached 72.7, 80, 80, 82.2 and 83.3% within 2, 4, 6, 8 and 10 weeks post vaccination, respectively. In the other words, the mortality level in vaccinated groups was in range of 10-20% within 10 weeks post vaccination, while those of control group was in range 56.7 - 73.3% [p<0.05] .The lowest and the highest antibody titers in immunized groups were 32 +/- 4.50 and 164.57 +/- 9.37 respectively, obtained after 4 and 10 weeks of immunization, whereas the control group had no measurable titer of antibody. The results of this study clearly show that this vaccine can remarkably protect the trout from yersiniosis outbreaks inside Iran

Isolation of bovine spermatogonial cells and co-culture with prepubertal sertoli cells in the presence of colony stimulating factor-1

Spermatogonial stem cells [SSCs] are infrequent self-renewing cells among the type A spermatogonia within the seminiferous tubules and are the basis of spermatogenesis in mammalian testis. An adequate number of SSCs is a primary requirement for the study of their behavior, regulation, and further biomanipulation. In this paper, we studied the development of the primary co-cultures of type A spermatogonia and prepubertal bovine sertoli cells in the presence of Colony Stimulating Factor 1 [CSF1], a potential contributor in the SSC niche. The effect of different concentrations of CSF1 [0, 10, 50 and 100 ng/mL] on the colonization activity of spermatogonial cells was assessed 4, 7 and 11 days after the beginning of the culture by counting the total number of colonies and measuring their area in each group of the present experiment. Immunofluorescent staining against OCT4 and vimentin led to the confirmation of the nature of both the SSCs and sertoli cells. Results showed that the total number of colonies from day 4 to 11 increased significantly in all groups, independent of CSF1 concentration. In addition, the total number and total area of colonies were higher [not significant] in 10 and 50 ng/mL CSF1 treatments than the control and 100 ng/mL CSF1 groups in all the three evaluations during the experiment. However, this difference was only significant [p<0.05] between the total area of colonies in the control and 10 ng/mLCSF1 groups at day 4 of co-culture. It was concluded that CSF1 can be a suitable growth factor for improving SSCs colonization in vitro, particularly during the first days of culture where accompanying sertoli cells still have not proliferated sufficiently to support the propagating spermatogonial cells

Effects of gamma irradiation on antioxidant activity of Ergosan

The approaches chosen for control of Outbreaks of infectious diseases in Aquatic farming industry include improvement of environmental conditions, stocking of specific pathogen free [SPF] brood stockings, and application of vaccines and immunostimulants. Despite numerous studies on the effects of Ergosan on immune system of aquatic animals, there is no data available on antioxidant activities of Ergosan. The aim of the present study was to investigate and evaluate the radical scavenging activities of Ergosan extract by DPPH [1, 1-diphenyl-2-picrylhydrazyl] free radical scavenging assay, and the possible effects of gamma irradiation on its assumed radical scavenging activities. Ergosan was irradiated with gamma rays [10, 20, 30, 40 and 50 kGy], and their structural changes and antioxidant activities were investigated by UV absorbanceand DPPH [1,1-diphenyl-2-picrylhydrazyl] assays, respectively. The gamma irradiation decreased the average pH of irradiated Ergosan, and UV spectra of irradiated product showed increase in the number of carboxyl groups and double bonds. Our results showed that 30 kGy irradiated Ergosan suspension had significant higher level of antioxidant activity in comparison with non-irradiated Ergosan [P<0.05]. Also, the reducing power values of 30 and 50 kGy irradiated Ergosan were higher than that of nonirradiated [P<0.05] and the other doses of irradiation couldn't make any significant difference in reducing power of Ergosan. Results indicate that the 30 kGy irradiated Ergosan might be an appropriate candidate for the use in aquatic animal diets as a natural antioxidant agent besides its immunostimulant role