Vidotto M C, Kano S F, Gregori F, Headley S A, Vidotto O
Departamento de Medicina Veterinária Preventiva, Centro de Ciências Agrárias, Campus Universitário, Universidade Estadual de Londrina, Londrina, PR, Brazil.
J Vet Med B Infect Dis Vet Public Health. 2006 Nov;53(9):404-11. doi: 10.1111/j.1439-0450.2006.00984.x.
Anaplasma marginale is an obligate intraerythrocytic rickettsial pathogen (order, Rickettsiales: family, Anaplasmataceae) that causes bovine anaplasmosis. This disease is widely distributed in tropical and sub-tropical regions of the world and causes important economic losses to cattle production. Major surface protein (MSP)1a (msp1alpha gene) is one of the six MSPs identified on A. marginale from cattle, whose sequence and size vary according to the number of tandem 28- to 29-amino acid repeats. This study characterized the msp1alpha and msp4 genes obtained from three distinct Brazilian herds from the State of Paraná. Three strains of the msp1alpha and one strain of the msp4 gene were sequenced. The strains evaluated revealed PCR products of different size, representing three, five and six internal repeats. Sequence analyses confirmed the number of tandem sequence copies and revealed a high degree of sequence identity with strains from other Brazilian States, as well as strains from the USA, Europe and Israel. The msp1alpha DNA and amino acid sequences from A. marginale and DNA sequences of msp4 strains did not reveal distinct phylogeographical segregation. However, the amino acid sequences of msp4 demonstrated definite phylogeographical relationship. These results suggest that the amino acid sequences of msp4 should be used for phylogenetic identification of A. marginale strains and may be an important tool for the epidemiology and control of anaplasmosis. Additionally, the close similarity of the Paraná strains of A. marginale with strains from USA, Europe and Asia may reflect the introduction of these genes during the development of the Brazilian bovine herd.
边缘无形体是一种专性红细胞内立克次氏体病原体（立克次氏体目：无形体科），可引起牛无浆体病。这种疾病广泛分布于世界热带和亚热带地区，给养牛业造成重大经济损失。主要表面蛋白（MSP）1a（msp1α基因）是在牛源边缘无形体上鉴定出的六种MSP之一，其序列和大小因28至29个氨基酸串联重复序列的数量而异。本研究对从巴拉那州三个不同巴西牛群中获得的msp1α和msp4基因进行了特征分析。对三株msp1α和一株msp4基因进行了测序。评估的菌株显示出不同大小的PCR产物，代表三个、五个和六个内部重复序列。序列分析证实了串联序列拷贝数，并显示与来自巴西其他州以及美国、欧洲和以色列的菌株具有高度的序列同一性。边缘无形体的msp1α DNA和氨基酸序列以及msp4菌株的DNA序列未显示出明显的系统地理隔离。然而，msp4的氨基酸序列显示出明确的系统地理关系。这些结果表明，msp4的氨基酸序列应用于边缘无形体菌株的系统发育鉴定，可能是无浆体病流行病学和防控的重要工具。此外，巴拉那州边缘无形体菌株与美国、欧洲和亚洲菌株的高度相似性可能反映了这些基因在巴西牛群发展过程中的引入。
