Diferentes fontes e níveis de selênio sobre a imunidade humoral de frangos de corte

The use of organic trace minerals is getting strength and is an alternative to increase production and improve other characteristics such as humoral immunity. The present study was conducted to evaluate the effect of different levels and sources of selenium (Se) on humoral immunity of broilers. A six-week research was conducted using 1440 one-day-old males broiler chickens. The experimental design was randomized with six experimental diets (A: 0.15mg kg(-1) inorganic (inorg.); B: 0.15mg kg(-1) organic; C: 0.15mg kg(-1) inorg. + organic; D: 0.45mg kg(-1) inorganic; E: 0.45mg kg(-1) organic; F: 0.45mg kg(-1) inorg. + organic) calculated to provide the described amount of Se. Each diet was replicated in six box with 40 birds. A 3x2 factorial arrangement was used and the data were analyzed by ANOVA. The immunity was evaluated by means of the reaction against vaccine of Newcastle disease, and a reaction against sheep red blood cells (SRBC). No significant effects were observed at 5% significance level in NewCastle antibody (P >0.05). However at 14 day-old the source factor had p value at 0.0580, that show a trend of inorganic source in prolong the maternal immunity. No effect was observed in the immune response against SRBC (P >0.05). The results showed a immunologic response against Newcastle vaccine and SRBC, but the treatments was not able to induce a significant difference. The source and the level of Se showed no effect on the response against Newcastle vaccine and SRBC.

Patologie da Porcine Circovirus tipo 2 (PCV2) nel suino

The main work involved the PMWS (Post-weaning multisystemic Wasting Syndrome), caused by PCV-2 (Porcine Circovirus type 2) that involved post-weaned pigs. Merial Italy has funded a study activity in which groups of 3-5 animals were sampled for lungs, tracheo-bronchial and superficial inguinal lymph nodes, ileum and tonsils. The protocol applied can be identified as a more diagnostic potential on the individual than on the group. PNP. Another investigation has been conducted to study proliferative and necrotizing pneumonia (PNP), a form of interstitial pneumonia in weaning and post-weaning pigs characterized by hypertrophy and hyperplasia of type II pneumocytes, coagulative necrosis and granular debris within alveolar spaces. Many studies suggest porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) as the main causes of the disease, but Aujeszky disease virus (ADV) and swine influenza virus (SIV) are also considered. An immunohistochemical study was carried out to evaluate the role of these viruses in PNP lesions in Italy. PNP results primarily associated with PRRSV, even if co-infection is characterized by more severe histological features. Reproductive pathology. A major risk factor for PCV2 infection is a viraemic episode taking place in pregnant sows with low antibody titer which is transmitted by specific PCV2 products of conception. PCV2 can infect the fetus even by vehicles through infected semen or ova, or as a result of infection of the genital tract. An investigation was carried out to identify the presence and localization of PCV2 in the genital tracts of sows experimentally infected with PCV2 and in their fetuses. The results obtained suggest that: conventional sows can be infected by intrauterine exposition; low antibody titres increase the probability of infection; PCV2 infection close to insemination time reduces the pregnancy rate; placental lesions may represent an additional cause of fetal suffering.

Epidemiological study of pestiviruses in South American camelids in Switzerland

BACKGROUND: In the context of the ongoing eradication campaign for bovine viral diarrhea virus (BVDV) in cattle in Switzerland, the role of South American camelids (SAC) as a possible virus reservoir needed to be evaluated. OBJECTIVE: To assess and characterize the prevalence of pestivirus infections in SAC in Switzerland. ANIMALS: Serum samples collected from 348 animals (40 herds) in 2008 and from 248 animals (39 herds) in 2000 were examined for antibodies against pestiviruses and for the presence of BVDV viral RNA. METHODS: Cross-sectional study using stratified, representative herd sampling. An indirect BVDV-ELISA was used to analyze serum samples for pestivirus antibodies, and positive samples underwent a serum neutralization test (SNT). Real-time RT-PCR to detect pestiviral RNA was carried out in all animals from herds with at least 1 seropositive animal. RESULTS: In 2008, the overall prevalence of animals positive for antibodies (ELISA) and pestiviral RNA or was 5.75 and 0%, respectively. In 2000, the corresponding prevalences were 3.63 and 0%, respectively. The seroprevalences (SNT) for BVDV, border disease virus or undetermined pestiviruses were estimated to be 0, 1.73, and 4.02% in 2008, and 0.40, 1.21, and 2.02% in 2000, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: At the present time, SAC appear to represent a negligible risk of re-infection for the BVDV eradication program in cattle in Switzerland.

Immunohistochemical screening for viral agents in cheetahs (Acinonyx jubatus) with myelopathy

Numerous cases of acute-onset progressive ataxia, hindlimb paresis and paralysis of unknown aetiology occurred during 1993 to 2003 in cheetahs (Acinonyx jubatus) within the European Endangered Species Programme (eep). This study describes the immunohistochemical investigation of a possible viral aetiology of the "cheetah myelopathy". Antibodies to feline herpesvirus type 1, canine distemper virus, canine parvovirus and Borna disease virus were applied to formalin-fixed and paraffin-embedded brain and spinal cord sections from 25 affected cheetahs aged between three-and-a-half months and 13 years. Using the avidin-biotin complex technique, none of the antibodies gave positive immunosignals in either the brain or the spinal cord tissue.

Seroprevalence and characterization of pestivirus infections in small ruminants and new world camelids in Switzerland

The seroprevalence of pestivirus infections in small ruminants and new world camelids in Switzerland was determined. In 5'059 sera of sheep from 382 herds, 503 sera of goats from 54 herds and 109 sera of alpacas and lamas from 53 herds, population prevalences of 16.1% (sheep), 25.4% (goats) and 4.6% (new world camelids), respectively, were found. In order to determine the source of infection, the serological reactions were further characterized by cross-neutralization against two pestiviruses representing the genotypes BVDV (Bovine Virus Diarrhea Virus)-1 and BDV (Border Disease Virus)-1. Based on the ratio of respective antibody titres, 56.1% of the infections in sheep were induced by a BDV-1, 12.9% by a BVDV-1 and 31.0% by an unresolved pestivirus. In goats, the corresponding proportions were 23.4%, 10.2% and 66.4%, respectively. In Alpacas and Lamas, the source of infection of 1 animal was BDV-1 and that of 4 seropositive animals remained unresolved. In view of the phylogenetic relationship between pestiviruses, the unresolved source of infection is most probably attributable to other pestivirus genotypes circulating in small ruminants and new world camelids. Due to the predominance of pestiviral genotypes other than BVDV-1, the risk of transmission of BVDV from persistently infected small ruminants and new world camelids to cattle appears to be moderate, apart from close direct contact in mixed animal husbandry, communal pasturing and grazing in the Alps.

Pestiviruses.

Pestiviruses cause economically important diseases among domestic ruminants and pigs, but they may also infect a wide spectrum of wild species of even-toed ungulates (Artiodactyla). Bovine viral diarrhea virus (BVDV) and Border disease virus of sheep infect their hosts either transiently or persistently. Cellular and humoral immunotolerance to the infecting strain is a unique feature of persistent infection (PI) by ruminant pestiviruses. Persistence, caused by transplacental infection early in fetal development, depends on virally encoded interferon antagonists that inactivate the host's innate immune response to the virus without globally interfering with its function against other viruses. At epidemiological equilibrium, approximately 1-2% of animals are PI. Successful BVDV control programs show that removal of PI animals results in viral extinction in the host population. The nucleotide sequences of ruminant pestiviruses change little during persistent infection. Nevertheless, they display large heterogeneity, pointing to a long history of virus-host coevolution in which avirulent strains are more successful.

Viral capsid mobility: A dynamic conduit for inactivation

Mass spectrometry and fluorescent probes have provided direct evidence that alkylating agents permeate the protein capsid of naked viruses and chemically inactivate the nucleic acid. N-acetyl-aziridine and a fluorescent alkylating agent, dansyl sulfonate aziridine, inactivated three different viruses, flock house virus, human rhinovirus-14, and foot and mouth disease virus. Mass spectral studies as well as fluorescent probes showed that alkylation of the genome was the mechanism of inactivation. Because particle integrity was not affected by selective alkylation (as shown by electron microscopy and sucrose gradient experiments), it was reasoned that the dynamic nature of the viral capsid acts as a conduit to the interior of the particle. Potential applications include fluorescent labeling for imaging viral genomes in living cells, the sterilization of blood products, vaccine development, and viral inactivation in vivo.

Synthetic transcripts of double-stranded Birnavirus genome are infectious.

We have developed a system for generation of infectious bursal disease virus (IBDV), a segmented double-stranded RNA virus of the Birnaviridae family, with the use of synthetic transcripts derived from cloned cDNA. Independent full-length cDNA clones were constructed that contained the entire coding and noncoding regions of RNA segments A and B of two distinguishable IBDV strains of serotype I. Segment A encodes all of the structural (VP2, VP4, and VP3) and nonstructural (VP5) proteins, whereas segment B encodes the RNA-dependent RNA polymerase (VP1). Synthetic RNAs of both segments were produced by in vitro transcription of linearized plasmids with T7 RNA polymerase. Transfection of Vero cells with combined plus-sense transcripts of both segments generated infectious virus as early as 36 hr after transfection. The infectivity and specificity of the recovered chimeric virus was ascertained by the appearance of cytopathic effect in chicken embryo cells, by immunofluorescence staining of infected Vero cells with rabbit anti-IBDV serum, and by nucleotide sequence analysis of the recovered virus, respectively. In addition, transfectant viruses containing genetically tagged sequences in either segment A or segment B of IBDV were generated to confirm the feasibility of this system. The development of a reverse genetics system for double-stranded RNA viruses will greatly facilitate studies of the regulation of viral gene expression, pathogenesis, and design of a new generation of live vaccines.

Local nitric oxide production in viral and autoimmune diseases of the central nervous system.

Because of the short half-life of NO, previous studies implicating NO in central nervous system pathology during infection had to rely on the demonstration of elevated levels of NO synthase mRNA or enzyme expression or NO metabolites such as nitrate and nitrite in the infected brain. To more definitively investigate the potential causative role of NO in lesions of the central nervous system in animals infected with neurotropic viruses or suffering from experimental allergic encephalitis, we have determined directly the levels of NO present in the central nervous system of such animals. Using spin trapping of NO and electron paramagnetic resonance spectroscopy, we confirm here that copious amounts of NO (up to 30-fold more than control) are elaborated in the brains of rats infected with rabies virus or borna disease virus, as well as in the spinal cords of rats that had received myelin basic protein-specific T cells.

Is the distribution of Fiji leaf gall in Australian sugarcane explained by variation in the vector Perkinsiella saccharicida?

Fiji leaf gall (FLG) is an important virally induced disease in Australian sugarcane. It is confined to southern canegrowing areas, despite its vector, the delphacid planthopper Perkinsiella saccharicida, occurring in all canegrowing areas of Queensland and New South Wales. This disparity between distributions could be a result of successful containment of the disease through quarantine and/or geographical barriers, or because northern Queensland populations of Perkinsiella may be poorer vectors of the disease. These hypotheses were first tested by investigating variation in the ITS2 region of the rDNA fragment among eastern Australian and overseas populations of Perkinsiella. The ITS2 sequences of the Western Australian P. thompsoni and the Fijian P. vitiensis were distinguishable from those of P. saccharicida and there was no significant variation among the 26P. saccharicida populations. Reciprocal crosses of a northern Queensland and a southern Queensland population of P. saccharicida were fertile, so they may well be conspecific. Single vector transmission experiments showed that a population of P. saccharicida from northern Queensland had a higher vector competency than either of two southern Queensland populations. The frequency of virus acquisition in the vector populations was demonstrated to be important in the vector competency of the planthopper. The proportion of infected vectors that transmitted the virus to plants was not significantly different among the populations tested. This study shows that the absence of FLG from northern Queensland is not due to a lack of vector competency of the northern population of P. saccharicida.

Husbandry and trade of indigenous chickens in Myanmar - results of a participatory rural appraisal in the Yangon and the Mandalay divisions

There is a variety of professions working with village chickens in developing countries, including farmers, veterinarians and chicken traders. People from all these occupations were involved in a participatory rural appraisal to investigate husbandry practices and trade of village chickens in Myanmar. Data were collected in two climatically different regions of the country, in the Yangon and in the Mandalay divisions. The breeding and training of fighting cocks was practised only in the Mandalay division, with well-trained birds sold for very high prices. Apart from this, chickens were raised in both regions mainly for small disposable income and were generally sold when money was needed, in particular during religious festivals. Chicken traders on bicycles, often called 'middle men', usually purchase birds from farmers in about 10 villages per day. Several 'middle men' supply birds to wealthier chicken merchants, who sell these birds at larger chicken markets. There is in general limited knowledge among farmers about the prevention of Newcastle disease via vaccination. Commercial indigenous chicken production is practised in Myanmar, but family poultry farming dominates indigenous chicken production in the country.

MOSQUITO CONTROL AND ZIKA

This checklist is a tool to help local governments prepare for mosquito season and potential mosquito-borne disease outbreaks. It contains recommended items to be considered as part of a Zika readiness plan.

Proposal to minimize the difficulty of recording abortion data in sheep

Background: The most frequent viral diseases which can cause abortion in sheep are Blue tongue, Border disease virus, Cache Valley fever and Schmallenberg virus. The diagnosis of abortion, namely virus-induced represents a challenge to field clinicians, since clinical signs presented by the dam are discrete, non-specific and variable (Agerhom et al., 2015). On the other hand, while some foetuses reveal characteristic and visible malformations, others do not reveal any lesions. In face of it, definitive diagnosis requires an appropriate history collection, as well as sending fresh samples, namely abortion material, foetus, placenta and umbilical cord, to a specialty laboratory, to obtain a precise diagnosis. Objectives: The authors suggest a registration method of all mandatory data, in order to further assist the diagnosis of viral diseases at the laboratories, including the most frequent congenital malformations reported in sheep abortions. Methods: Abortion samples of suspected viral origin were collected and all data were registered, in worktables optimized for this purpose. Results: The authors document, using macroscopic figures lesions of malformations in abortions, emphasizing the frequency and the importance of documenting each case, proposing practical and effective worktables to assist the fieldwork. Conclusions: Field clinician’s awareness of the importance of early detection of viral diseases causing abortion outbreaks stimulates a proper data collection for each case of abortion, in order to contribute to a precise diagnosis and posterior consistent epidemiological studies, which may allow diminishing of economic losses.

Trichomonas vaginalis is associated with pelvic inflammatory disease in women infected with human immunodeficiency virus

We assessed the association between the causative agents of vaginal discharge and pelvic inflammatory disease (PID) among women attending a rural sexually transmitted disease clinic in South Africa; the role played by coinfection with human immunodeficiency virus type 1 (HIV-1) was studied. Vaginal and cervical specimens were obtained to detect Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, and bacterial vaginosis. HIV-1 infection was established by use of serum antibody tests. A total of 696 women with vaginal discharge were recruited, 119 of whom had clinical PID. Patients with trichomoniasis had a significantly higher risk of PID than did women without trichomoniasis (P = .03). PID was not associated with any of the other pathogens. When the patients were stratified according to HIV-1 status, the risk of PID in HIV-1-infected patients with T. vaginalis increased significantly (P = .002); no association was found in patients without HIV-1. T. vaginalis infection of the lower genital tract is associated with a clinical diagnosis of PID in HIV-1-infected women.

Lower numbers of circulating natural killer T (NK T) cells in individuals with human T lymphotropic virus type 1 (HTLV-1) associated neurological disease

Human T lymphotropic virus type 1 (HTLV-1) infects 10-20 million people worldwide. The majority of infected individuals are asymptomatic; however, approximately 3% develop the debilitating neurological disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). There is also currently no cure, vaccine or effective therapy for HTLV-1 infection, and the mechanisms for progression to HAM/TSP remain unclear. NK T cells are an immunoregulatory T cell subset whose frequencies and effector functions are associated critically with immunity against infectious diseases. We hypothesized that NK T cells are associated with HAM/TSP progression. We measured NK T cell frequencies and absolute numbers in individuals with HAM/TSP infection from two cohorts on two continents: Sao Paulo, Brazil and San Francisco, CA, USA, and found significantly lower levels when compared with healthy subjects and/or asymptomatic carriers. Also, the circulating NK T cell compartment in HAM/TSP subjects is comprised of significantly more CD4(+) and fewer CD8(+) cells than healthy controls. These findings suggest that lower numbers of circulating NK T cells and enrichment of the CD4(+) NK T subset are associated with HTLV-1 disease progression.