Optimization of short-term storage of pikeperch semen: an applicable approach.

Contamination of semen with urine and asynchronous maturation of males and females are main obstacles in artificial reproduction of pikeperch Sander lucioperca. The objective of this study was to overcome these obstacles using optimization of a procedure for short-term storage of pikeperch semen at 4°C using two immobilizing media (IM): (a) IM1, 180mM NaCl, 2.68mM KCl, 1.36mM CaCl2⋅2H2O and 2.38mM NaHCO3, 343mOsm/kg; and (b) IM2, 200mM NaCl, 2.68mM KCl, 1.36mM CaCl2⋅2H2O and 2.38mM NaHCO3, 381mOsm/kg. Undiluted sperm was used as the control. At 6h poststorage, there were no substantial changes in spermatozoa motility and velocity at 30s postactivation in all groups. Over 48h of storage, the highest spermatozoa motility and velocity were obtained in sperm diluted in IM2 compared to the other groups. IM2 could maintain a significantly higher ATP content of diluted sperm than IM1 and undiluted treatment for 2days. Similarly, the highest values of eyeing and hatching rates were observed in sperm diluted in IM2 compared to sperm in the other studied groups. It can be concluded that the obtained result is a novel and applicable approach to maintain semen quality of pikeperch during short-term storage, suggesting IM2 as a promising medium for short-term storage. The present study also opens possibilities for ensuring a reliable source of semen as a convenient approach for increasing genetic diversity in hatcheries.

Assessment of type I interferons, clinical signs and virus shedding in broiler chickens with pre and post challenge Newcastle disease vaccination.

BACKGROUND: Newcastle disease (ND) causes devastating economic losses in poultry industry. AIMS: This study evaluates the plausible effect of prior or post challenge vaccination with a live commercial vaccine on some pathogenic aspects of velogenic Newcastle disease virus (vNDV) infection in broilers with an emphasis on elucidating type I interferons (IFNs) response trends. METHODS: Chicks (n=250) were randomly allocated into 5 equal groups including negative control (NC), positive control (PC) (challenged with vNDV), and treatment (T1-T3) groups: (T1) only received Villegas-Glisson/University of Georgia (VG/GA) strain of NDV vaccine, (T2) vaccinated 24 h prior to vNDV challenge, and (T3) vaccinated 24 h post vNDV challenge. Samples from trachea, cloacal content, and serum were collected at different time points to evaluate virus shedding or IFNs levels. RESULTS: Although clinical signs and lesions were not completely blocked by administration of vaccine prior to or post vNDV inoculation, the disease severity diminished as demonstrated by an increase in bird's survival rate and median survival days (MSDs). Moreover, prior to or post challenge VG/GA live vaccine administration, modified viral shedding patterns by decreasing the vNDV shedding period especially from the gastrointestinal (GI) system. Strong early type I IFNs response was observed in the trachea and sera of chickens vaccinated prior to or post-infection (pi) as compared to birds that received vaccine or vNDV alone. In trachea, IFN-α response was more pronounced than IFN-ß, while both IFNs showed a considerable change in serum. CONCLUSION: It seems that vaccination after challenge with vNDV can improve bird's health similar to prior administration and reduces virus shedding which may be due to type I IFNs production.

Infectious bursal disease virus suppresses H9N2 avian influenza viral shedding in broiler chickens.

1. Infectious bursal disease virus (IBDV) causes immunosuppression in chickens, increasing their susceptibility to other infectious diseases and resulting in vaccination failure. Here, we investigated the immune-depressing effect of IBDV on H9N2 avian influenza viral infection in the broiler chickens. 2. For this purpose, chickens were divided into four groups. In group A, chickens were inoculated with IBDV at 21 days of age and H9N2 avian influenza virus (AIV) 5 days later. Groups B and C only received AIV at 26 days of age and IBDV at 21 days, respectively. The control group (D) were inoculated with normal saline at the same times. Tissue samples from different organs were collected on the days 1, 3, 6, 9, and 12 after H9N2 infection. 3. Macroscopic observation showed IBD lesions in groups A and C, including swollen bursa with the presence of gelatinous exudates, haemorrhages in the thigh muscle, edema, and nephritis. 4. Reverse Transcription-PCR was used to study H9N2 AIV dissemination, and qRT-PCR to determine viral genome copy number in different organs. A considerable titre of AIV was found in the trachea, lungs, cecal tonsils, spleens, and feces of infected chickens. The genome copy number of the virus in the trachea and lungs of group A was significantly higher than that in group B on the first day after inoculation. But in the other days post inoculation, RT-PCR did not detect the AIV genome in group A. Although there might have been some immunosuppression in group A, IBDV could interfere with AIV replication in the chickens of this group. 5. In conclusion, we propose that pre-exposure to IBDV at 3 weeks of age reduces the replication and shedding of H9N2 in broiler chicken.

Evaluation of the timing of the Escherichia coli co-infection on pathogenecity of H9N2 avian influenza virus in broiler chickens.

Bacterial co-infections can probably influence the pathogenicity of H9N2 low pathogenic avian influenza virus (AIV). This study aimed to evaluate the effect of exposure time to Escherichia coli (O:2) on the pathogenicity of H9N2 AIV in broiler chickens. Three hundred and sixty broiler chickens were randomly allocated to six equal groups. At the age of 26 days, all chicks except groups 5 and 6 were inoculated intra-nasally with H9N2 virus. At the same time, the birds in groups 1 and 5 were infected with E. coli via spray route. Birds in groups 3 and 2 were infected with E. coli three days prior to and three days post AI challenge, respectively. Mortality rates, clinical signs, gross and microscopic lesions, excretion and duration of virus shedding in faecal and tracheal samples and seroconversion to H9N2 virus were assessed in the challenged groups. The highest mortality rate was observed in chickens inoculated with H9N2 followed by E. coli. The most severe clinical signs, gross lesions, mortality rate and virus detection were observed at day 6 post challenge (PC) in birds of group 2, while the duration of virus shedding was longer in group 3 (E. coli followed by H9N2) than other groups. In conclusion, E. coli infection prior to, after or concurrently with H9N2 virus infection could exacerbate the adverse effects of the virus. Our results indicate that E. coli and H9N2 together can mutually exacerbate the condition of either disease in broiler chicks as compared to single infected birds.

Gonad histology and serum 11-KT profile during the annual reproductive cycle in sterlet sturgeon adult males, Acipenser ruthenus.

The aim of this study was to assess monthly testicular development in the cultured breeding stock of sterlet, Acipenser ruthenus, using histological and serum sex steroid changes. Testicular development in the adult male was examined monthly and showed four distinct phases including resting, pre-spawning, spawning and post-spawning. Also, seasonal changes of the testes were described according to its variations in gonadosomatic index (GSI) during different phases of testicular development. Using histology, we identified continuous spermatogenesis and asynchronous gonad development pattern in the testes of male sterlet, which shows that regulation of annual gonadal cycle is influenced by season. Results also showed variation in the GSI value and number of spermatogenic cells according to each season during annual cycle of gonad, as the highest value of GSI was recorded during spawning phase (spring; March-May). Hormonal profiles of 11-ketotestosterone (11-KT) showed peak, which indicated a seasonal pattern of gonadal development. The 11-KT concentration increased considerably during the spermatogenesis (pre-spawning phase) and remained quite high throughout the pre-spermiation period. In the final phase of testicular development (spawning phase), the 11-KT markedly dropped. This study undertook an examination of complete reproductive development in cultured sterlet sturgeon to provide a valuable guide for the future sterlet studies, and allows comparison of reproductive development between sturgeon species.

Effects of Lactobacillus acidophilus and inulin on faecal viral shedding and immunization against H9 N2 Avian influenza virus.

AIMS: The aims of this investigation were to compare the effects of Lactobacillus acidophilus addition as simple or microencapsulated (ME) probiotic and inulin as prebiotic to the broiler diet on the faecal viral shedding and immunization against avian influenza virus (AIV) with or without H9 N2 vaccination. METHODS AND RESULTS: Simple or ME forms of Lact. acidophilus, inulin and combination of them as synbiotic were analysed for their ability to enhance immunity against H9 N2 AIV and to decrease faecal viral shedding in Cobb-500 broiler chicks. Our results indicated that probiotic as ME form can decrease haemagglutination inhibition (HI) titre significantly on days 34 in vaccinated trial (P < 0·05). Also, the effects of ME form of probiotic are more remarkable on reduction of viral faecal shedding detected by RT-PCR. CONCLUSIONS: The study shows the significant role of microencapsulation on probiotic effects against H9 N2 AIV. SIGNIFICANCE AND IMPACT OF THE STUDY: The application of probiotics especially in the ME form could have the potential for stimulating the immune system, preventing influenza infection and consequently reduce faecal viral shedding of H9 N2 AIV.

Coinfection of avian influenza virus (H9N2 subtype) with infectious bronchitis live vaccine.

Avian influenza virus of H9N2 subtype is pathotyped as a non-highly pathogenic virus. However, frequent incidences of avian influenza of high mortality that are caused by H9N2 viruses have been observed in broiler chicken farms in Iran and some other Asian countries. Coinfections or environmental factors may be involved in such cases. Infectious microorganisms have been implicating in taking part in the cases of coinfection. We studied the effect of experimental coinfection of H9N2 avian influenza virus with infectious bronchitis live vaccine, which is used extensively in chicken farms in Iran. Clinical signs, gross lesions, viral shedding and mortality rate of the experimentally infected birds were examined. Coinfection of infectious bronchitis live vaccine and H9N2 avian influenza virus led to an extension of the shedding period of H9N2 virus, increasing the severity of clinical signs and mortality rates, causing macroscopic lesions in the embryos.

Pathobiology of H9N2 avian influenza virus in Japanese quail (Coturnix coturnix japonica).

Clinical signs, serologic response, viral contents of the trachea and intestine, and histopathological and ultrastructural changes of the tracheal epithelium of Japanese quail experimentally infected with field isolate of H9N2 avian influenza were studied. Vaccinated and unvaccinated quail were inoculated with 10(6.3) 50% embryo infectious dose/bird of A/ chicken/Iran/SH-110/99 (H9N2) virus via nasal inoculation. Clinical signs such as depression, ruffled feathers, diarrhea, and nasal and eye discharges were observed 6 days postinfection (PI). No mortality was observed; however, there was reduction in feed and water consumption and egg production. However, the serologic response of vaccinated challenged and unvaccinated challenged birds was not significantly different. Unvaccinated challenged quail showed more severe histopathologic reaction in their lungs and trachea. Hyperemia, edema, infiltration of inflammatory cells, and deciliation and sloughing of the tracheal epithelium were observed. Ultrastructural study showed dilatation of endoplasmic reticulum and degeneration of Golgi apparatus and cilia of the tracheal lining cells of respiratory epithelium.

A scanning soft x-ray microscope with an ellipsoidal focusing mirror.

We have developed and brought into operation a new type of scanning soft x-ray microscope which can operate at any photon energy from 20 to 1300 eV. This microscope demagnifies a diaphragm by means of an annular section of an ellipsoidal mirror to a smallest spot size of, at present, about 0.4 µm (FWHM), certainly containing only a small fraction of the total intensity. The sample is scanned across this spot. Between mirror and focus a free space of 30 mm is available for detectors, and particles emitted from a surface at more than 30° to the normal can be extracted into a mass or energy analyzer. Transmission, photoemission, luminescence, photostimulated desorption, reflectivity, and other signals may serve for imaging. In addition, a static analysis of very small samples or spots on a sample will become feasible.