| Autor: |
Nobre AFS; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brasil., Almeida DS; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brasil., Ferreira LC; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brasil., Ferreira DL; Instituto Evandro Chagas, Ananindeua, Pará, Brasil., Júnior ECS; Instituto Evandro Chagas, Ananindeua, Pará, Brasil., Viana MNDSA; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brasil., Silva IC; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brasil., Pinheiro BT; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brasil., Ferrari SF; Department of Ecology, Universidade Federal de Sergipe, Sergipe, Brazil., Linhares ADC; Instituto Evandro Chagas, Ananindeua, Pará, Brasil., Ishikawa EA; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brasil., Sousa RCM; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brasil., de Sousa MS; Núcleo de Medicina Tropical, Universidade Federal do Pará, Belém, Pará, Brasil. |
| Abstrakt: |
The Human T-cell Lymphotropic Virus (HTLV-1) is a Deltaretrovírus that was first isolated in the 1970s, and associated with Adult T-cell Leucemia-Lymphoma (ATLL), and subsequently to Tropical Spastic Paraparesis-Myelopathy (TSP/HAM). The genetic diversity of the virus varies among geographic regions, although its mutation rate is very low (approximately 1% per thousand years) in comparison with other viruses. The present study determined the genetic diversity of HTLV-1 in the metropolitan region of Belém, in northern Brazil. Blood samples were obtained from patients at the UFPA Tropical Medicine Nucleus between January 2010 and December 2013. The DNA was extracted and the PX region of the HTLV was amplified using nested PCR. The positive samples were then digested using the Taq1 enzyme for the identification and differentiation of the HTLV-1 and HTLV-2. The 5'LTR region of the positive HTLV-1 samples were amplified by nested PCR, and then sequenced genetically. The phylogenetic analysis of the samples was based on the maximum likelihood method and the evolutionary profile was analyzed by the Bayesian approach. Overall, 78 samples tested positive for HTLV-1, and 44 were analyzed here. The aA (cosmopolitan-transcontinental) subtype was recorded in all the samples. The following evolutionary rates were recorded for the different subtypes-a: 2.10-3, b: 2.69. 10-2, c: 6.23. 10-2, d: 3.08. 10-2, e: 6. 10-2, f: 1.78. 10-3, g: 2.2. 10-2 mutations per site per year. The positive HTLV-1 samples tested in the present study were characterized by their low genetic diversity and high degree of stability. |
