The pathogenicity and biological features of Santee-Cooper Ranaviruses isolated from Chinese perch and snakehead fish.

Ranavirus has become a noticeable threat to both farmed and natural populations of fish and amphibians. Herein, we reported that 3 strains of novel viruses, designated as ScRIV-GM-20150902, CmRIV-XT-20150917 and ScRIV-ZS-20151201, were isolated from diseased Chinese perch and snakehead fish in China. Efficient propagation of these isolates were determined in Chinese perch brain (CPB) cell line by the means of cytopathic effect observation, PCR amplification and electron microscopy observation. And their viral titers in CPB cells reached 108.13 TCID50 ml-1, 107.71 TCID50 ml-1 and 107.94 TCID50 ml-1, respectively. While the challenge experiment results showed that 3 isolates resulted in 100% mortality of Chinese perch after virus infection. Electron microscopy analysis showed that two kinds of viral inclusion bodies (intracytoplasmic and intranuclear inclusion body) were observed in infected CPB cells. Sequence alignment and phylogenetic analysis of major capsid protein gene sequences of isolates revealed that these isolates belonged to the species Santee-Cooper Ranavirus.

Molecular detection of kobuviruses in livestock in Northern Ireland and the Republic of Ireland.

Kobuviruses have been detected in a wide range of mammals including cats, dogs, pigs, cattle, goats, sheep and bats. Kobuviruses have been detected in symptomatic and asymptomatic animals; however, the clinical significance of infection in animals is still unclear. To date, there is no information regarding kobuvirus prevalence in livestock in Ireland. This study reports the first detection of kobuviruses in pigs, bovines and ovines using quantitative PCR. In this study, mesenteric lymph node was collected from cattle (n = 57), pigs (n = 53) and sheep (n = 50) from farms in Northern Ireland and the Republic of Ireland, from animals which had been submitted by private veterinary practitioners from 2009 to 2011 for routine post mortem and clinico-pathological examination. Kobuviruses were detected in 14 cows (24.5%), 5 pigs (9.4%) and 1 sheep (2%). Phylogenetic analysis of Irish kobuviruses from cattle and pigs revealed that the isolates clustered according to their host species. Interestingly, the sheep kobuvirus clustered with bovine kobuviruses detected in this study and other published kobuvirus strains. The data presented in this study contributes to the understanding of the epidemiology of these viruses in animals and to the genetic diversity that these viruses possess.

Synchronous hepatic, mesenteric and pulmonary Epstein-Barr virus-associated smooth muscle tumors in a renal transplant recipient.

Epstein-Barr virus-associated smooth muscle tumors (EBV-SMT) are distinct lesions that occur in immunocompromised patients. EBV-SMT following solid organ transplantation are rare and generally have an indolent biological behavior. Post-transplant EBV-SMT have been reported in various anatomical locations. This report describes a synchronous and multicentric development of EBV-SMT in liver, mesentery, and lung of a 33-yr-old male patient, 10 yr after a deceased allograft renal transplantation. The hepatic and mesenteric tumors were available for study. These tumors were composed of bland looking, desmin-positive, spindle-shaped cells which showed a strong nuclear staining for EBV with in situ hybridization technique. A literature review of post solid organ transplant EBV-SMT in the liver and lung, particularly regarding their pathogenesis, synchronicity and biological behavior would be provided.

Detection and genetic typing of type 2 porcine circoviruses in archived pig tissues from the UK.

Porcine circovirus 2 (PCV-2) is implicated as the causative agent of post-weaning multisystemic wasting syndrome (PMWS) and is also associated with porcine dermatitis and nephropathy syndrome (PDNS). The recent emergence of epidemic PMWS in the United Kingdom was predated by sporadic cases of PDNS dating back to the early 1980's. The aim of this study was to investigate whether PCV-2 DNA was present in archival tissues, and if so, to investigate the relatedness of these viruses with contemporary strains of PCV-2. DNA extracted from paraffin wax-embedded tissue blocks ( n = 68), was subjected to a TaqMan polymerase chain reaction (PCR) targeting a fragment of ORF1 of PCV-2. Positive results were obtained from 41% (9/22), 31% (4/13) and 32% (8/25) of submissions from the 1990's, 1980's and 1970's respectively. The presence of PCV-2 antigen in some of these tissues was confirmed by immunohistochemistry (IHC). A PCR targeting ORF2 was used to obtain sequence data for phylogenetic analysis. Sequences from 5 archival tissues were unique but showed high genetic identity to PCV-2 sequence obtained from a 2000 PDNS case. These data demonstrate that similar isolates of PCV-2 have been present in the UK pig population for more than 30 years.

Hypertrophy, hyperplasia, and infectious virus in gut-associated lymphoid tissue of mice after oral inoculation with simian-human or bovine-human reassortant rotaviruses.

Oral inoculation of infants with a vaccine that contains simian-human reassortant rotaviruses has been found to be a rare cause of intussusception. Because intussusception can be associated with enlargement of gut-associated lymphoid tissue, we studied the capacity of simian-human and bovine-human reassortant rotaviruses to cause lymphoid hypertrophy and hyperplasia of Peyer's patches (PP) of adult BALB/c mice. Neither hypertrophy nor hyperplasia was detected in PP after oral inoculation with simian-human or bovine-human reassortant rotaviruses. However, infectious virus was detected in PP and mesenteric lymph nodes after oral inoculation with simian, but not bovine, reassortant rotaviruses. Implications of these findings on the pathogenesis of intussusception are discussed.

Further evidence of the absence of measles virus genome sequence in full thickness intestinal specimens from patients with Crohn's disease.

Specimens of macroscopically inflamed and normal intestine along with mesenteric lymph nodes were obtained at resection from patients with Crohn's disease. The samples were systematically examined by RT-PCR-nested PCR targeting N, M and H gene regions of the measles virus genome. None of the samples examined gave any evidence of the persistence of measles virus in the intestine of Crohn's disease patients. The study supports previous findings produced by this laboratory and others using highly sensitive measles virus specific PCR diagnostic technology.

Quantitation of virus-specific classes of antibodies following immunization of mice with attenuated equine herpesvirus 1 and viral glycoprotein D.

The antibody responses of CBA/J mice infected intranasally (i.n.) with either the attenuated KyA strain or the pathogenic RacL11 strain of equine herpesvirus 1 (EHV-1) or immunized with recombinant glycoprotein D (rgD) were investigated using the ELISPOT assay to measure EHV-1-specific antibody-secreting cells (ASC) in the regional lymphoid tissue of the respiratory tract. IgG, IgA, and IgM ASC specific for EHV-1 were detected in the mediastinal lymph nodes (MLN) and lungs 2 weeks after i.n. infection with EHV-1 strain KyA or RacL11, or immunization with heat-killed KyA or rgD. EHV-1-specific ASC were present in the MLN and lungs at 4 and 8 weeks, but declined in frequency by fivefold in the lung at 8 weeks. However, i.n. immunized (2 x 10(6) pfu KyA or 50 microgram rgD/mouse) mice infected at 8 weeks with pathogenic EHV-1 RacL11 resisted challenge and showed eight- and tenfold increases in MLN ASC and lung ASC, respectively, by 3 days after challenge. In contrast to the intranasal route of immunization, intraperitoneal immunization yielded ASC frequencies in the MLN and lungs that were only slightly above those of nonimmunized control mice. These data indicate that immunization with infectious or heat-killed EHV-1 KyA, or rgD, induces significant levels of virus-specific ASC both in the MLN and lungs, a specific memory B-cell response, and long-term protective immunity. The finding that the numbers of ASC induced by the pathogenic strain versus the attenuated strain of EHV-1, which were virtually identical, indicated that the ability to generate a B-cell response is independent of and does not contribute to EHV-1 virulence.

[Smooth muscle mesentery associated with Epstein-Barr virus (EBV). Report of a case in a child with a liver transplant under FK506 regimen]. / Tumeur musculaire lisse mésentérique associée au virus d'Epstein-Barr (EBV). A propos d'un cas chez un enfant transplanté hépatique sous FK 506.

Smooth-muscle tumors, benign and malignant, are increasingly recognized in children who are immunocompromised because of HIV infection and organ transplantation. We report a case of an EBV-associated smooth-muscle tumor, of unusual location arising in a seven-year-old post-transplant patient who was previously treated for a lymphoproliferative disease. Five years after liver transplantation, a mesenteric tumor was diagnosed. The tumor was composed of spindle cells with smooth-muscle features. Immunohistochemical analysis was positive for muscle-specific actin and desmin, negative for EBV latent membrane protein (LMP-1). In situ hybridization revealed nuclear EBV sequences. This case underlines the role of EBV infection in the development of unusual smooth-muscle tumors after organ transplantation. The evolution of these rare tumors is uncertain.

Rotavirus-specific proteins are detected in murine macrophages in both intestinal and extraintestinal lymphoid tissues.

Rotaviruses replicate in mature, villous epithelial cells of the mammalian small intestine. Although rotavirus has not been detected in plasma of infants with rotavirus-induced gastroenteritis, rotavirus particles and rotavirus genomic RNA have been detected in extraintestinal sites (e.g. cerebrospinal fluid). Using a murine rotavirus strain well adapted to growth in the small intestines of suckling mice, we found that macrophages (and to a lesser extent B cells) in gut-associated lymphoid tissue contained rotavirus-specific proteins, and that these antigen-containing cells travelled to sites distant to the intestine.

Pathology of experimental Ebola virus infection in African green monkeys. Involvement of fibroblastic reticular cells.

BACKGROUND: Ebola virus has been responsible for explosive lethal outbreaks of hemorrhagic fever in both humans and nonhuman primates. Previous studies showed a predilection of Ebola virus for cells of the mononuclear phagocyte system and endothelial cells. OBJECTIVE: To examine the distribution of lesions and Ebola virus antigen in the tissues of six adult male African green monkeys (Cercopithecus aethiops) that died 6 to 7 days after intraperitoneal inoculation of Ebola-Zaire (Mayinga) virus. METHODS: Tissues were examined histologically, immunohistochemically, and ultrastructurally. RESULTS: A major novel finding of this study was that fibroblastic reticular cells were immunohistochemically and ultrastructurally identified as targets of Ebola virus infection. CONCLUSIONS: The role of Ebola virus-infected fibroblastic reticular cells in the pathogenesis of Ebola hemorrhagic fever warrants further investigation. This is especially important because of recent observations indicating that fibroblastic reticular cells, along with the reticular fibers they produce, maximize the efficiency of the immune response.