Doenças infecciosas e parasitárias em suínos no Nordeste do Brasil.

Abstract

This thesis is composed of three chapters on infectious diseases in swine diagnosed at the Animal Pathology Laboratory, Hospital Veterinário Universitário Prof. Dr. Ivon Macedo Tabosa, from the Federal University of Campina Grande, Patos, Paraíba. The first chapter describes the clinicopathological, immunohistochemical and molecular characterization findings in two cases of systemic toxoplasmosis in swine in Brazil. The clinical signs observed were apathy and dyspnea. Macroscopically, the lungs were non-collapsed, diffusely reddened, and multiple nodules of caseous necrosis were observed in the parenchyma. Histologically, there was bronchointerstitial, necrotizing, diffuse, accentuated pneumonia with numerous intralesional tachyzoites of T. gondii. Immunohistochemistry, performed with anti- T. gondii in lung tissue revealed strong immunostaining of free tachyzoites and cysts. Nested PCR targeting a 155-bp fragment of the B1 gene of T. gondii was positive. Genotyping was performed using PCR-RFLP and microsatellites, characterizing the non-archetype Chinese genotype 1. The second chapter describes the epidemiological, clinicopathological and molecular findings of outbreaks of swinepox virus infection in the semiarid region of the Northeastern. Five outbreaks of smallpox caused by the swinepox virus (SWPV) occurred in swine herds in two municipalities in the state of Rio Grande do Norte (2008-2014). Clinical signs started with coalescing gray or whitish papules and vesicles that usually progressed to crusted lesions, and in some cases, there were ulcers. Macroscopically, papules, reddish pustules, sometimes covered by crusts, were observed, affecting more severely the ears, periocular region, abdomen and thoracic and pelvic limbs. Histologically, proliferative and ulcerative dermatitis with ballooning degeneration of epithelial cells was observed, with eosinophilic viral inclusions in the cytoplasm of keratinocytes. SWPV was confirmed by sequencing and phylogenetic analysis. The diagnosis was made based on epidemiological, clinicopathological findings and confirmed by molecular tests. The third reports the clinical and pathological findings of swine demodicosis in a swine in the semiarid region of Paraíba, Brazil. In clinical examination, firm, multifocal to coalescing nodules associated with crusts and moderate alopecia were observed. When manipulated, such nodules expelled yellowish semi-solid content, evidencing purulent secretion. The lesions were concentrated in the lateral region of the thorax, abdomen, all limbs, head and ears. Incisional biopsy and histopathological evaluation were performed. Macroscopically, irregular nodules were observed on the surface, with multiple crusts and desquamation. On section, it exhibited a whitish surface with multiple areas forming cavitations filled with yellowish material. Histologically, there was granulomatous to perivascular dermatitis and folliculitis associated with mites morphologically compatible with the Demodex genus. The diagnosis of demodicosis was based on the macroscopic and microscopic findings associated with the parasitological examination. The diseases diagnosed in swine in the LPA/HVU/UFCG occur sporadically, however they cause significant economic losses in the region, mainly in subsistence farming. Many pathologies are infectious and their emergence is directly related to nutritional and sanitary management failures. It is suggested that other studies be carried out, mainly in a more comprehensive way, in order to determine the pathologies that occur in swine in the different regions of the Brazilian Northeastern, so that basic measures of control and prevention of infections in the subsistence swine are suggested, minimizing significant economic losses for small producers.