Carlos Mazur

Characterization of neutrophil extracellular traps in cats naturally infected with feline leukemia virus

Feline leukemia virus (FeLV), a common, naturally occurring gammaretrovirus in domestic cats, is associated with degenerative diseases of the haematopoietic system, immunodeficiency and neoplasia. FeLV infection causes an important suppression of neutrophil function, leading to opportunistic infections. Recently, a new microbicidal mechanism named NETosis was described in human, bovine and fish neutrophils, as well as in chicken heterophils. The purpose of the present study was to characterize NETosis in feline neutrophils, as well as to evaluate neutrophil function in FeLV naturally infected symptomatic and asymptomatic cats through the phagocytosis process, release of neutrophil extracellular traps (NETs) and myeloperoxidase (MPO) activity. The results showed that feline neutrophils stimulated with protozoa parasites released structures comprising DNA and histones, which were characterized as NETs by immunofluorescence. Quantification of NETs after neutrophil stimulation showed a significant increase in NET release by neutrophils from FeLV(-) and FeLV(+) asymptomatic cats compared with FeLV(+) symptomatic cats. Moreover, the number of released NETs and MPO activity in unstimulated neutrophils of FeLV(+) symptomatic cats were higher than those in unstimulated neutrophils from FeLV(-) and FeLV(+) asymptomatic cats. This study reports, for the first time, NET release by feline neutrophils, along with the fact that NET induction may be modulated by a viral infection. The results indicate that the NET mechanism appears to be overactivated in FeLV(+) cats and that this feature could be considered a marker of disease progression in FeLV infection.

Detection of poxvirus in cattle associated with human cases in the State of Rio de Janeiro: preliminary report

This preliminary report describes human and cow cases of poxvirus that recently occurred in the State of Rio de Janeiro. The electron microscopic findings were consistent with parapoxviral and orthopoxviral infection. Orthopoxvirus strains were isolated from human and cow cases. Detailed viral characterization by means of genetical techniques is under investigation. Based on these informations, poxviral diseases should be also considered an emerging viral zoonosis that can affect human beings.

Detection and phylogenetic analysis of Orf virus from sheep in Brazil: a case report

BackgroundOrf virus (ORFV), the prototype of the genus Parapoxvirus (PPV), is the etiological agent of contagious ecthyma, a severe exanthematic dermatitis that afflicts domestic and wild small ruminants. Although South American ORFV outbreaks have occurred and diagnosed there are no South American PPV major membrane glycoprotein B2L gene nucleotide sequences available.Case presentationan outbreak of ovine contagious ecthyma in Midwest Brazil was investigated. The diagnosis was based on clinical examinations and molecular biology techniques. The molecular characterization of the virus was done using PCR amplification, cloning and DNA sequencing of the B2L gene. The phylogenetic analysis demonstrated a high degree of identity with ORFV strains, and the isolate was closest to the ORFV-India 82/04 isolate. Another Brazilian ORFV isolate, NE1, was sequenced for comparative analysis and also showed a high degree of identity with an Asian ORFV strain.ConclusionDistinct ORFV strains are circulating in Brazil. This is the first report on the phylogenetic analysis of an ORFV in South America.

Nested-multiplex PCR detection of Orthopoxvirus and Parapoxvirus directly from exanthematic clinical samples

BackgroundOrthopoxvirus (OPV) and Parapoxvirus (PPV) have been associated with worldwide exanthematic outbreaks. Some species of these genera are able to infect humans and domestic animals, causing serious economic losses and public health impact. Rapid, useful and highly specific methods are required to detect and epidemiologically monitor such poxviruses. In the present paper, we describe the development of a nested-multiplex PCR method for the simultaneous detection of OPV and PPV species directly from exanthematic lesions, with no previous viral isolation or DNA extraction.Methods and ResultsThe OPV/PPV nested-multiplex PCR was developed based on the evaluation and combination of published primer sets, and was applied to the detection of the target pathogens. The method showed high sensitivity, and the specificity was confirmed by amplicon sequencing. Exanthematic lesion samples collected during bovine vaccinia or contagious ecthyma outbreaks were submitted to OPV/PPV nested-multiplex PCR and confirmed its applicability.ConclusionThese results suggest that the presented multiplex PCR provides a highly robust and sensitive method to detect OPV and PPV directly from clinical samples. The method can be used for viral identification and monitoring, especially in areas where OPV and PPV co-circulate.

Vírus da doença de Newcastle em aves não vacinadas no Estado do Rio de Janeiro

The Newcastle disease virus (NDV) has been isolated in most of the species of free and domestic life all over the world. The international trade of birds should be considered as an important factor of disease spread. Natural and experimental infections were already demonstrated in, at least, 236 species of birds. Therefore, wild, free or captive, and non vaccinated domestic birds can act as reservoir for VDN. To analyze this hypothesis, birds from the municipal Zoo of Rio de Janeiro and from private properties in the municipal districts of Seropedica, Japeri, Paulo de Frontin, Paracambi, Valenca, Barra do Pirai, Rio de Janeiro and Nova Friburgo, RJ, Brazil had their blood collected and plasmas stored for detection of antibodies levels for VDN. A panel of 837 plasmas was obtained, in the period of August of 1998 to July of 2001, and analyzed by the hemaglutination inhibition (HI) test, from which 12 were soropositives (1.43%) for NDV, indicating the contact of the birds with the pathogen.

Prevalence of feline leukemia virus infection in domestic cats in Rio de Janeiro

Peripheral blood smears of 1094 domestic cats were collected and tested by indirect immunofluorescence antibody assay for p27 antigen in cells to study the prevalence and risk factors for feline leukemia virus (FeLV) in the state of Rio de Janeiro. Sex, age, breed, outdoor access, neutering status, type of habitation (household, shelter, veterinary clinics and other places), number of household cats and clinical signs were registered on a form. Among the tested samples, 11.52% were positive. Risk factors for FeLV infection included outdoor access, age range between 1 and 5 years old, and cohabitation with numerous cats.

Performance of a latex agglutination test in the diagnosis of acute gastroenteritis by rotavirus

The aim of this work was to determine the performance of latex agglutination test (LAT) for evaluating children acute gastroenteritis by rotavirus. The LAT showed good sensitivity, as well as specificity and predictive positive value and due to its simplicity and speed, it has been suitable for rotavirus diagnosis in hospital laboratories.

Oral administration of piperine for the control of aflatoxin intoxication in rats.

Aflatoxins are mycotoxins that have important toxic effects on human and animal health, even if consumed at low doses. The oral administration of piperine (1.12 mg/kg) during 23 days in rats seemingly interfered with the toxicity of aflatoxins, decreasing hepatic injuries and the leukocyte depletion in experimentally intoxicated animals.

Prevalência de anticorpos para o vírus da Influenza Eqüina, subtipo H3N8, em eqüídeos apreendidos no Estado do Rio de Janeiro

The Influenza virus type A, subtype H3N8, is the etiological agent of the Equine Influenza, responsible for several epidemics and endemic respiratory diseases in world level, besides in the Rio de Janeiro State, Brazil. The objective of this work was to evaluate the role of errant equids, as infectious sources of the Influenza virus, subtype H3N8. The survey was performed from the research of specific antibodies for this virus in 1106 sera analyzed by the inhibition of the hemagglutination test. The high percentile (35,9%) of seropositive animals found in this study evidenced its importance as infectious sources of the Influenza virus, subtype H3N8, to the national equine flock.

Isolamento e caracterização biológica da amostra JAP99 do vírus da doença de Newcastle isolada de patos domésticos (Neta sp) no Rio de Janeiro

Newcastle disease virus (NDV) is the etiological agent of one of the most important diseases of the poultry industry and it has been identified in most of the avian species, wild and domestic birds. In this work, the isolation of the sample denominated JAP99 was obtained from duck feces collected in Japeri, RJ, which was identified by hemagglutination-inhibition technique (HI). The biological characterization of the pathogenicity of the new isolate was investigated at the Animal Regional Laboratory, Ministry of Agriculture, Campinas, SP. By intracerebral inoculation in one day chicks, the index was 1.4. In the intravenous inoculation in birds of six weeks, the index found was 0.0 and the mean death time in chicken embryos was 62 hours. These results pointed out that the isolate JAP99 is mesogenic for commercial chickens, offering risk for the poultry industry.