Characterization and importance of Cattle Tick Fever and study of the genetic variability of Anaplasma marginale (Theiler, 1910) in calves from the northwestern region of Minas Gerais, Brazil

Autor: Silva, Michele Bahia do Vale
Přispěvatelé: Fonseca, Adivaldo Henrique da, Silva, Cl?udia Bezerra da, Silva, Jenevaldo Barbosa da, Silva, F?bio Jorge Moreira da, Vilela, Joice Aparecida Rezende, Massard, Carlos Luiz, Santos, Huarrisson Azevedo, Peixoto, Maristela Peckle
Jazyk: portugalština
Rok vydání: 2019
Předmět:
Zdroj: Biblioteca Digital de Teses e Dissertações da UFRRJ
Universidade Federal Rural do Rio de Janeiro (UFRRJ)
instacron:UFRRJ
Popis: Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2022-07-21T17:29:34Z No. of bitstreams: 1 2019 - Michele Bahia do Vale Silva.pdf: 2232740 bytes, checksum: 322f1c2ee1b47d848889c9f5d45a6270 (MD5) Made available in DSpace on 2022-07-21T17:29:34Z (GMT). No. of bitstreams: 1 2019 - Michele Bahia do Vale Silva.pdf: 2232740 bytes, checksum: 322f1c2ee1b47d848889c9f5d45a6270 (MD5) Previous issue date: 2019-10-02 CAPES - Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior This work is divided into two chapters and aims 1) to characterize the importance of rickettsia Anaplasma marginale and the protozoan parasites Babesia bovis and Babesia bigemina in the occurrence of cattle tick fever (CTF) among calves in the Northwest region of Minas Gerais and 2) to evaluate the relationship between A. marginale genetic diversity and the anaplasmosis outbreaks occurrence in dairy farms same region. In the first chapter, Blood samples from 300 calves were collected and after DNA extraction Nested-PCR was performed using oligonucleotide primers that amplified fragments of the genes sbp-4 (B. bovis) and rap-1a (B. bigemina) and Semi-Nested for the gene msp5 (A. marginale). Blood smears were made from these animals. The prevalence of A. marginale 55,66% (167/300), B. bigemina. 15,33% (46/300) and B. bovis 4,0 % (12/300) of calves examined by techinques of PCR. Parasitic forms of A. marginale and B. bigemina were found in 36,33% and 2,66% of the blood smears while B. bovis was not detected. Infection rates by age in group 1 (10-70 days) were 41.12%, 26.16% and 3.73% for A. marginale, B. bigemina and B. bovis, respectively. While in group 2 (> 70-300 days) the prevalences were 63.73%, 9.32% and 4.14% for the same agents, respectively. Fifteen animals with fever, weight loss, jaundice and anemia were examined and nested-PCR confirmed the simple infection by A. marginale. For chapter II, Thirty previously positive calves (msp5 gene) for A. marginale with asymptomatic (n = 24) and acute (n = 6) infection were selected for the study of genetic diversity through semi-nested PCR targeting the msp1? gene. After sequencing of the samples, the genotype and tandem repeats structures were determined. Thirteen different strains were found: : ??FFF (9 animals), 13 27 27 (3 animals), ? 27 18 (3 animals), ??? 195 31 (3 animals), ? 22 13 18 (3 animals), 80 FFFF (2 animals), ? 22 13 13, ????, M????F, 42 25 25 31, QQQM, BQBQBM, 1617FF (1 animal each). Genotype E was predominant in 93.33% of the samples (28/30), followed by genotypes C (3.33%) and G (3.33%). A new repeated tandem structure was described in the present work named BRA 1 (TDSSSASGVLSQSGQASTSSQLG). The ??FFF strain was present in six febrile animals that showed clinical sintoms of anaplasmosis like weight loss, jaundice and anemia. In the bovine herd studied anaplasmosis is the main cause of CTF. High genetic diversity of A. marginale occurred in persistently infected animals. However, during outbreaks of bovine anaplasmosis, low genetic diversity was observed. The ??FFF strain in northwestern Minas Gerais was associated with acute anaplasmosis. Genotype E was predominate. Este trabalho est? dividido em dois cap?tulos e tem por objetivos: 1) Caracterizar a import?ncia da rickettsia Anaplasma marginale e dos protozo?rios Babesia bovis e Babesia bigemina na ocorr?ncia do complexo da Tristeza Parasit?ria Bovina (TPB) em bezerros na regi?o Noroeste de Minas Gerais 2) avaliar a rela??o entre a diversidade gen?tica de A. marginale e a ocorr?ncia de surtos de anaplasmoses em bezerros da mesma regi?o. No primeiro cap?tulo foram coletadas 300 amostras sangu?neas de bezerros e ap?s extra??o de DNA foi realizada Nested- PCR utilizando oligonucleot?deos iniciadores que amplificam fragmentos dos genes sbp-4 (B. bovis) e rap-1a (B. bigemina) e a Semi-Nested para o gene msp5 (A. marginale). Esfrega?os sangu?neos foram confeccionados destes animais. A preval?ncia de A. marginale foi de 55,66% (167/300), B. bigemina 15,33% (46/300) e B. bovis 4,0% (12/300) nos animais examinados por t?cnicas de PCR. Formas parasit?rias de A. marginale e B. bigemina foram encontradas em 36,33% e 2,66% dos esfrega?os sangu?neos, enquanto B. bovis n?o foi detectado. As taxas de infec??es por faixa et?ria no grupo 1 (10-70 dias) de bezerros foram de 41,12%, 26,16% e 3,73% para A. marginale, B. bigemina e B. bovis, respectivamente. Enquanto no grupo 2 (> 70-300) as preval?ncias foram de 63,73%, 9,32% e 4,14% para os mesmos agentes, respectivamente. Foram examinados 15 animais com febre, perda de peso, mucosas hipocoradas, icter?cia e anemia, sendo confirmados posteriormente por nested-PCR a infec??o simples por A. marginale, todos animais pertenciam ao grupo 2. Para o segundo cap?tulo foram selecionados 30 bezerros previamente positivos (gene msp5) para A. marginale com infec??o assintom?tica (n=24) e aguda (n=6) para o estudo da diversidade gen?tica atrav?s da semi-nested PCR com alvo no gene msp1?. Ap?s o sequenciamento das amostras foi determinado o gen?tipo e estruturas em tandem repeats. Treze diferentes estirpes foram encontradas ??FFF (9 animais), 13 27 27(3 animais), ? 27 18 (3 animais), ??? BRA1 31 (3 animais), ? 22 13 18 (3 animais), 80 FFFF (2 animais), ? 22 13 13, ????, M????F, 42 25 25 31, QQQM, BQBQBM, 1617FF (um animal cada). O gen?tipo E foi predominante em 93,33% das amostras (28/30), seguidos pelos os gen?tipos C (3,33%) e G (3,33%). Uma nova estrutura repetida em tandem foi descrita no presente trabalho nomeada BRA 1 (TDSSSASGVLSQSGQASTSSQLG). A estirpe ??FFF esteve presente em seis animais com sinais cl?nicos de anaplasmose aguda com sinais cl?nicos de febre, perda de peso, icter?cia e anemia. No Rebanho bovino estudado a anaplasmose ? a principal causa de Tristeza Parasit?ria bovina. Alta diversidade gen?tica de A. marginale ocorreu em animais persistentemente infectados. Entretanto durante surtos de anaplasmose bovina foi observada baixa diversidade gen?tica. A estirpe ??FFF na regi?o noroeste de Minas Gerais foi associada a anaplasmose aguda. O gen?tipo E foi predomina-te.
Databáze: OpenAIRE
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