11 research outputs found

    Study on viral nervouse necrosis (isolation, characterisation and pathogenesis) in golden grey mullet in the Caspian Sea and study of pathogenecity and possibility of transmission to the other fish species (Sturgeon fishes, Rutilus frisii kutum and reared Rainbow trout and Carp)

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    Study on Viral Nervouse necrosis (isolation, characterisation and pathogenesis) in Golden grey mullet in the Caspian Sea and study of pathogenecity and possibility of transmission to the other fish species (Sturgeon fishes, Rutilus frisii kutum and reared Rainbow trout and Carp) Viral Nervous Necrosis (VNN) is a worldwide disease affecting several species of cultured marine fish. For the past two decades, betanodavirus infections that cause Viral Nervous Necrosis (VNN) have emerged as major constraints on the culture and sea ranching of marine fish in almost all parts of the world. More than forty species mainly of marine origin have been so far affected and this number is likely to rise in future following the introduction of new species and the increase of aquaculture trade. Unknown acute mortality occurred in wild golden grey mullet Lisa auratus and Liza saliens in Iranian waters of Caspian Sea in recent years. In order to isolation and confirmation of causative agents of golden grey mullet mortality in the Caspian Sea, a complementary research investigation project was designed in 2005 and approved immediately in Iranian Fisheries Research Organization (IFRO). Many diagnostic aspects such as Virology (Cell culture and Elctereone Microscopy), Hemathology, Bacteriology, Histopathology, Molecular biology (NestedRT-PCR), Heavy metals measuerment and Serology (IFAT and IHC) were employed in mentioned multidiciplinary project. About 322 moribund fish samples which revealed skin darkening, erratic swimming behavior such as spiral and belly-up at rest and high distention of swimming bladder. Suspected samples were collected from coastal capture sites in iranian north proviences in 2006 till 2009. Targets tissue such as brain and eye were removed in strile condition and then kept in -80oC frezzer for cell culture and Nested-RT-PCR. Other tissue samples from liver, kidney, intestine, stomach, gill, skin and muscle, gall bladder and gonads were taken and fixed in 10% buffer formalin and same parts fixed in glutaraldehyde 3% for histopathology, IHC and EM respectively. Cytopathic effect (CPE) was observed in those cell cultures just six days after inoculation with the dilutions of the tested 312 homogenate supernatants. CPE in monolayers of cells cultured (SSN-1 cell line) was characterised by thin or rounded, refractile, granular cells with vacuoles. Nine samples were positive in virology assay. Nested- RT-PCR was done on suspected tissue samples and supernatant of CPE positive samples and 21 tissue samples and all CPE positive samples were positive. IFAT was selected as a confirmatory method for identifying viral strains replicating on cell cultures and carried out with rabbit anti-betanodavirus serum on suspected tissue samples and some smears of CPE positive samples. Some bright points approved betanodavirus antigen and confirmed cell culture and Nested-RT-PCR findings. In fixed tissue samples widespread and massive vacuolation were observed in brain, spinal cord, retina and optical nerve. In order to confirmation of diagnostic findings , IHC was done with monoclonal antibody antibetanodavirus and some red-brown points were observed. Theses findings revealed expected viral antigens and confirmed previous results. Moreover, virus particles with 25-30 nm in diameter were visualized in infected brain and retina using positive staining in TEM. Also pathogenicity test was employed to confirm the obtained results. So Guppy fish Poecilia reticulata and sturgeon fry were used instead of the experimental host due to ease of handling and susceptibility. After 15 days post infection, guppy bathed in VNN-infected tissue culture with 104 TCID50 showed clinical signs similar to naturally infected Golden grey mullet, and the mortality rate reached up to 100% in 75 dpi. When target organs were examined by cell culture isolation, serology, and histopathology, all revealed the presence of virus in the Guppy. Suspected supernatant injected to sturgeon fry through intravitreous injection and widespread vacuolation were observed in brain and spinal cord buy IHC and Real time PCR were negative. In conclusion, with attntion to obtained results in this investigation such as ecological factors, clinical signs, histopathological, virological and bacteriological results, molecular analysis, (IHC, IFAT, PCR), TEM demonstration, serological and hematological findings, it could be confirmed that VNNV was the main causative agent for disease outbreak in Golden grey mullet in Southern coastline of Caspian Sea

    Epidemiological Study of Rabies Infection in Specimens Sent to Pasteur ‎Institute of Iran in 2015‎

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    BACKGROUND AND OBJECTIVE: Rabies is an acute untreatable fatal encephalitis, which is fully preventable. Determination of prevalence and the main source of the virus can help with controlling and eradicating the disease. This study aimed to evaluate the prevalence of rabies in the suspicious specimens submitted to the national reference center for rabies, Pasteur Institute of Iran, during March-August 2015. METHODS: This cross-sectional study was performed on 195 rabies-suspected specimens of brain tissue. The diagnosis was done based on the determination Negri bodies through direct immunofluorescence method. In addition, rabies infection was evaluated in terms of animal type and geographic distribution. FINDINGS: The results showed that the prevalence rate of rabies infection was 59.5% (116 specimens). This infection was mostly observed among dogs, so that from 116 cases of positive rabies, 45 cases were canine (39%). In categorizing the specimens into carnivorous and ruminant, it was found that rabies was more prevalent in carnivorous animals (p=0.01). In terms of geographic distribution, the most cases of positive rabies were reported in Khorasan Razavi province with 23 positive cases (24.2%). CONCLUSION: Rabies infection is highly prevalent in carnivorous animals, especially dogs, and it is still considered as a dangerous zoonotic disease

    Natural infection with rabies virus: A histopathological and immunohistochemical study of human brains

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    Objectives: Despite all the efforts and increased knowledge of rabies, the exact mechanisms of infection and mortality from the rabies virus are not well understood. To understand the mechanisms underlying the pathogenicity of rabies virus infection, it is crucial to study the tissue that the rabies virus naturally infects in humans. Methods: Cerebellum brain tissue from 9 human post mortem cases from Iran, who had been infected with rabies virus, were examined histopathologically and immunohistochemically to evaluate the innate immune responses against the rabies virus. Results: Histopathological examination revealed inflammation of the infected cerebellum and immunohistochemical analyses showed an increased immunoreactivity of heat shock protein 70, interleukin-6, interleukin-1, tumor necrosis factor-alpha, caspase-3, caspase-9, toll-like receptor3 and toll-like receptor4 in the infected brain tissue. Conclusion: These results indicated the involvement of innate immunity in rabies infected human brain tissue, which may aggravate the progression of this deadly disease. © 2019 Korea Centers for Disease Control and Prevention. This is an open access article under the CC BY-NC-ND licens

    Rotavirus VP7, VP4 and VP6 genotypes co-circulating in Tehran, Iran, between 2003 and 2004

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    Rotaviruses were detected by enzyme-linked immunosorbent assay (ELISA) in 92 out of 374 faecal samples collected between November 2003 and October 2004 at the Markaz Tebbi Koudakan Hospital, Tehran, Iran, from children aged 6 months to 5 years. Analysis of clinical and disease severity data showed a significant association between rotavirus infection and diarrhoea, vomiting and severe dehydration. Ninety-two samples (64 rotavirus ELISA-positive and 28 ELISA-negative samples) were sent to the Enteric Virus Unit, Virus Reference Department, Centre for Infection, Health Protection Agency, UK for rotavirus characterization by G-typing, P-typing and subgrouping (SG) using reverse transcriptase (RT)–PCR, semi-nested PCR and sequencing methods. In this study, both common and uncommon rotavirus genotypes were detected. The most prevalent types were G1P[8], SGII (59·2%) followed by G9P[8] SGII (15·5%) which has not been previously reported from Iran. Unusual genotypes G1P[10] SGI (2·8%) and G12P[8] SGII (1·4%) and strains derived from reassortment between common co-circulating genotypes such as G1P[4] SGII represented 5·6% of strains. Mixed infections with combinations of G1+G4P[8] SGII and G1+G9P[8] SGII were also found. This contrasts with previous reports from Iran in which a small number of common rotavirus strains (G1 and G4) were found. This study highlights the need for continued surveillance and characterization of rotaviruses to take account of the rapid evolution and introduction of novel rotaviruses into the human population

    The Middle East and Eastern Europe rabies Expert Bureau (MEEREB) third meeting: Lyon-France (7–8 April, 2015)

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    MEEREB is an inter-regional network of countries from North Africa, Europe, the Middle East and Central Asia that work together with the aim of improving rabies control and prevention at local, regional and global level. MEEREB members met for the third time in 2015 in France (Lyon) to review the current rabies situation within the network and to discuss the way forward the prospect of a One Health approach against rabies. Dogs were the main vector of transmission in all MEEREB countries except for Croatia and Serbia where foxes represented the primary source. The number of rabies animal cases reported in 2014 varied substantially between countries with Ukraine reporting the highest number of animal cases. Human cases still occur in North Africa and all Middle East and Eurasian countries while no cases of human rabies were reported in Croatia, Serbia and Romania, although cases of rabies were identified in both dogs and foxes in 2014. Participants concluded that MEEREB can act as a think-tank where countries can share data, information, experiences and best practices to jointly address challenges in rabies control and prevention. They called for elimination of dog-transmitted rabies through vaccine and rabies immunoglobulin stockpiles and implementation of a One Health approach to achieve rabies’s eradication. Keywords: MEEREB, Rabies, Epidemiology, Repor
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