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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Low genetic diversity of Anaplasma marginale in calves in an endemic area for bovine anaplasmosis in the state of Sao Paulo, Brazil

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da Silva, Jenevaldo Barbosa [1] ; Andre, Marcos Rogerio [1] ; Machado, Rosangela Zacarias [1]
Total Authors: 3
[1] Fac Ciencias Agr & Vet, Dept Patol Vet, Jaboticabal, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: TICKS AND TICK-BORNE DISEASES; v. 7, n. 1, p. 20-25, 2016.
Web of Science Citations: 5

Major surface protein 1a has been used as a marker for genetic stability in identifying geographical isolates of Anaplasma marginate. We conducted a longitudinal study to ascertain the genetic diversity of A. marginate in a dairy cattle herd with a history of clinical anaplasmosis. A total of 20 calves were evaluated every 3 months, from birth to 1 year of age. They were evaluated using blood smears, IFAT, ELISA, and qPCR. Additionally, samples positive for the msp1a gene using nPCR were sequenced. The detection of A. marginate ranged from 20 to 90% using blood smears, 20-80% using ELISA/IFAT, and 15-100% using qPCR. We found evidence that suggested transplacental transmission of A. marginate in 15% (3/20) of the calves based on qPCR and 20% (4/20) based on blood smears. Additionally, these four animals were A. marginate ELISA/IFAT-positive. The A. marginate strains found were alpha-beta(3)-Gamma (n = 7), alpha-beta(2) (n = 1), and alpha-beta(2)-190-Gamma (n = 1). The new MS1a tandem repeat 190 was described. The results showed that the genetic diversity of A. marginate in a group of calves up to 1 year of age from Taiacu (SP) was low, with only three different strains identified, showing the microsatellite genotype E. Eighty percent of the animals evaluated had clinical signs of bovine anaplasmosis and were treated using oxytetracycline and imidocarb dipropionate. Additionally, it was found that 30% (6/20) and 10% (2/20) of the animals required a second and third treatment, respectively, based on clinical signs. Four animals infected with the alpha-beta(3)-Gamma strain died, showing that this strain is also involved in the clinical anaplasmosis cases in Brazil. (C) 2015 Elsevier GmbH. All rights reserved. (AU)

FAPESP's process: 12/21371-4 - Antigenic variation of Anaplasma marginale and expression of major surface proteins
Grantee:Rosangela Zacarias Machado
Support type: Regular Research Grants