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Brucellosis and tuberculosis in cattle in South America
2018
José Soares Ferreira Neto
In general, European and North American countries, as well as Australia and New Zealand, have already eradicated or reached good levels of control of brucellosis and tuberculosis in cattle. In the rest of the world, however, the epidemiological situation of these two diseases is frequently poorly understood. In this review article, quantified data on these diseases in the South American countries are presented. Initially, the aspects that led the continent to host 25% of the world cattle population are presented, in addition to the aspects that placed the continent at a prominent position in the international meat market. Subsequently the continent was divided into three country groups, considering the size of the cattle population and how well the epidemiological situation of brucellosis and tuberculosis in cattle is quantified. It is argued that countries that do not generate high-quality quantitative epidemiological data on these diseases have serious limitations in outlining and managing control or eradication strategies. Thus, for successful outcomes, at least methodologies to estimate the prevalence of infected herds should be employed.
Afficher plus [+] Moins [-]Comparative leukocyte morphometric analysis between endemic Anurans from Brazil and the invasive species Lithobates catesbeianus
2017
Stephanie Moira Rodrigues e Silva | Ana Carolina Ewbank | Ricardo de Francisco Strefezzi | Gilbert Alvarado | Carlos Sacristan | Cátia Dejuste de Paula | José Luiz Catão-Dias
Amphibians are potentially reliable and efficient bioindicators. Existing anuran white blood cell morphology studies are limited, with only a few morphometric studies available. We employed morphometric techniques to characterize leukocytes of selected Neotropical anurans from Brazil and compare our findings with the exotic American Bullfrog (Lithobates catesbeianus), genus Ranidae. We compared blood smears of 28 specimens from six different genera (Hyla, Phyllomedusa, Hypsiboas, Scinax, Physalaemus, and Proceratophrys) with samples from L. catesbeianus. Leukocyte average diameter was calculated by an image analysis software. One-way analyses of variance and Bonferroni tests were used on statistical analyses. Lymphocytes, neutrophils, eosinophils, and basophils were significantly smaller than the reference ranges reported for other amphibian genera, including Lithobathes, whereas monocyte diameters did not differ significantly between genera. This is the first study to evaluate leukocyte morphometrics of Brazilian anuran species. Our findings suggest that geographical separation could possibly influence leukocyte morphometry.
Afficher plus [+] Moins [-]Roles of African swine fever virus structural proteins in viral infection
2017
Jia, Ning | Ou, Yunwen | Pejsak, Zygmunt | Zhang, Yongguang | Zhang, Jie
African swine fever virus (ASFV) is a large, double-stranded DNA virus and the sole member of the Asfarviridae family. ASFV infects domestic pigs, wild boars, warthogs, and bush pigs, as well as soft ticks (Ornithodoros erraticus), which likely act as a vector. The major target is swine monocyte-macrophage cells. The virus can cause high fever, haemorrhagic lesions, cyanosis, anorexia, and even fatalities in domestic pigs. Currently, there is no vaccine and effective disease control strategies against its spread are culling infected pigs and maintaining high biosecurity standards. African swine fever (ASF) spread to Europe from Africa in the middle of the 20ᵗʰ century, and later also to South America and the Caribbean. Since then, ASF has spread more widely and thus is still a great challenge for swine breeding. The genome of ASFV ranges in length from about 170 to 193 kbp depending on the isolate and contains between 150 and 167 open reading frames (ORFs). The ASFV genome encodes 150 to 200 proteins, around 50 of them structural. The roles of virus structural proteins in viral infection have been described. These proteins, such as pp220, pp62, p72, p54, p30, and CD2v, serve as the major component of virus particles and have roles in attachment, entry, and replication. All studies on ASFV proteins lay a good foundation upon which to clarify the infection mechanism and develop vaccines and diagnosis methods. In this paper, the roles of ASFV structural proteins in viral infection are reviewed.
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