Caracterização soroepidemiológica da infecção por Leptospira spp. em rebanhos bovinos de corte do Estado de Mato Grosso do Sul, Brasil
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Data
2017-10-20
Autores
Santos, Renata Ferreira dos [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Objetivou-se investigar as características epidemiológicas da leptospirose em bovinos e em rebanhos de corte em um dos principais estados pecuaristas brasileiros, Mato Grosso do Sul, de modo a determinar a frequência, as sorovariedades presentes, os fatores de risco associados à infecção pela Leptospira spp., isolar cepas de Leptospira de urina de bovinos de corte e, além disso, comparar os resultados obtidos utilizando a coleção de antígenos de referência com aqueles obtidos usando a coleção de antígenos de estirpes de leptospiras isoladas no Brasil. Para isso, foram analisadas 4.629 amostras de soro sanguíneo de bovinos de corte, machos e fêmeas, de diferentes idades, de 10 rebanhos, as quais foram testadas contra uma coleção de 33 sorovariedades de Leptospira. Para isolamento, as amostras de urina foram provenientes de animais de cinco rebanhos, totalizando 182 amostras. Inicialmente as amostras de soro sanguíneo foram submetidas à prova de Soroaglutinação Microscópica (MAT) para o diagnóstico sorológico da leptospirose, adotando-se como ponto de corte o título ≥ 100, e posteriormente foram coletadas amostras de urina dos bovinos para isolamento de Leptospira. Observou-se que, dos 4.629 animais avaliados pelo teste de MAT, foram observados 3.814 (82,39%) sororreagentes a pelo menos uma das 33 sorovariedades utilizadas de Leptospira spp., com título igual ou acima de 1:100 a uma ou mais sorovariedade de leptospira. Os sorovares mais prováveis de infecção foram: Wolffi 36,49% (905/2480), Shermani 18,43% (457/2480) e Hebdomadis 8,66% (215/2480). A frequência de reagentes entre as fêmeas foi maior que entre os machos. Não se isolou o microrganismo dos animais de nenhum dos cinco rebanhos. Quando realizada a comparação utilizando a coleção de antígenos de referência com a coleção de antígenos de estirpes de leptospiras isoladas no Brasil, houve aumento de 1,23% (57 amostras) na positividade na MAT. Nesse sentido, observou-se alta frequência de animais reagentes, demonstrando a relevância da infecção pelo agente etiológico no Estado; logo, medidas gerais e específicas devem ser implementadas de modo a conter e/ou prevenir a infecção nos animais dessa região.
This study investigated the epidemiological characteristics of bovine leptospirosis in animals and herds in Mato Grosso do Sul, the state with one of the largest herds in Brazil, to determine the frequency, the serovars present in the beef cattle herds, and the risk factors associated with Leptospira spp., isolate Leptospira strains from the urine of beef cattle, and compare the serology results of this study to a collection of reference antigens. A total of 4,629 serum samples were collected from male and female animals of different ages, from 10 different herds, and tested against 33 Leptospiraserovars. Initially, the serum samples were submitted to the Microscopic Agglutination Test (MAT) for the serological diagnosis of leptospirosis, the cut-off point ≥ 100, and subsequently, urine samples, totaling 182, were collected from animals in five herds for isolation of Leptospira. The MAT results showed that of the 4,629 animals evaluated, 3,814 (82.39%) were seroreactive to at least one of the 33 Leptospira spp. serovars used, with a titer equal to or greater than 1:100 to one or more Leptospira serovars. The most prevalent serovars were Wolffi 36.49% (905/2,480), Shermani 18.43% (457/2,480) and Hebdomadis 8.66% (215/2,480). The frequency of reactive animals was higher among females compared to males. The microorganism was not successfully isolated from the animals of any of the five herds. The comparison between the collection of reference antigens and the leptospire strains found in Brazil showed an increase of 1.23% (57 samples) in the MAT positivity. The observed high frequency of reactive animals demonstrates the relevance of the infection by the etiological agent in the state and, therefore, general and specific measures should be implemented to contain and/or prevent infection of the animals in the studied region.
This study investigated the epidemiological characteristics of bovine leptospirosis in animals and herds in Mato Grosso do Sul, the state with one of the largest herds in Brazil, to determine the frequency, the serovars present in the beef cattle herds, and the risk factors associated with Leptospira spp., isolate Leptospira strains from the urine of beef cattle, and compare the serology results of this study to a collection of reference antigens. A total of 4,629 serum samples were collected from male and female animals of different ages, from 10 different herds, and tested against 33 Leptospiraserovars. Initially, the serum samples were submitted to the Microscopic Agglutination Test (MAT) for the serological diagnosis of leptospirosis, the cut-off point ≥ 100, and subsequently, urine samples, totaling 182, were collected from animals in five herds for isolation of Leptospira. The MAT results showed that of the 4,629 animals evaluated, 3,814 (82.39%) were seroreactive to at least one of the 33 Leptospira spp. serovars used, with a titer equal to or greater than 1:100 to one or more Leptospira serovars. The most prevalent serovars were Wolffi 36.49% (905/2,480), Shermani 18.43% (457/2,480) and Hebdomadis 8.66% (215/2,480). The frequency of reactive animals was higher among females compared to males. The microorganism was not successfully isolated from the animals of any of the five herds. The comparison between the collection of reference antigens and the leptospire strains found in Brazil showed an increase of 1.23% (57 samples) in the MAT positivity. The observed high frequency of reactive animals demonstrates the relevance of the infection by the etiological agent in the state and, therefore, general and specific measures should be implemented to contain and/or prevent infection of the animals in the studied region.
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Palavras-chave
Leptospirose, bovinocultura de corte, Soroaglutinação Microscópica (MAT), estirpes brasileiras, Leptospirosis, Beef cattle, Microscopic Agglutination Test (MAT), Brazilian strains