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Abstract：
Ehrlichia chaffeensis is a bacterium belonging to the Anaplasmataceae family. In Mexico, only 2 species have been recorded in association with tick species and humans. The objective of the present study was to detect the presence of bacteria of the genus Ehrlichia in ticks collected from the Chamela-Cuixmala Biosphere Reserve, Jalisco, Mexico. The collected ticks were identified and analyzed individually by polymerase chain reaction to amplify a fragment of the Anaplasmataceae 16S rRNA gene and the Ehrlichia-specific dsb gene. A total of 204 ticks, corresponding to 5 species of Ixodidae and 1 of Argasidae, were collected from 147 mammals of 6 species and 4 orders; 57 ticks collected from vegetation were also included. Among the total ticks collected, 1.47% (3/204) was positive for Ehrlichia sp. DNA was obtained using the primers EHR 16SD and EHR 16SR for 16S rRNA and DSB-330 and DSB-728 for dsb. The positive samples corresponded to a larva (Amblyomma sp.) associated with Didelphis virginiana and 2 nymphs (Amblyomma cf. oblongoguttatum) infesting Nasua narica. None of the ticks collected from the vegetation tested positive for Ehrlichia sp. DNA on the basis of the 16S rRNA and dsb genes. The sequences from the larvae of Amblyomma sp. and the nymphs of A. cf. oblongoguttatum were similar to those of E. chaffeensis. The phylogenetic analysis inferred with maximum likelihood corroborated the identity as E. chaffeensis. Although the role of these tick species as vectors of E. chaffeensis is still undetermined, the presence of infected ticks in the area indicates a potential zoonotic risk.
摘要：
恰菲埃里希菌是一种属于无性子科的细菌。在墨西哥,只记录了2种与蜱种和人类有关的物种。本研究的目的是检测从Chamela-Cuixmala生物圈保护区收集的蜱中埃里希菌属细菌的存在，哈利斯科州,墨西哥。通过聚合酶链式反应对收集的蜱进行鉴定和单独分析，以扩增义齿科16SrRNA基因和埃里希菌特异性dsb基因的片段。总共204只蜱，对应于5种Ixodidae和1种Argasidae，从6种4目的147种哺乳动物中收集；还包括从植被中收集的57只蜱。在收集的全部蜱中，1.47%(3/204)的埃里希菌属阳性。使用针对16SrRNA的引物EHR16SD和EHR16SR以及针对dsb的DSB-330和DSB-728获得DNA。阳性样品对应于幼虫（Amblyommasp。)与Didelphisvirginiana和2个若虫(Amblyomma参见夜蛾）侵染乳母。从植被中收集的蜱虫均未检测出埃里希菌属阳性。基于16SrRNA和dsb基因的DNA。来自Amblyommasp。幼虫的序列。和A.cf.的若虫。oblongoguttatum与查菲氏大肠杆菌相似。以最大似然推断的系统发育分析证实了查菲大肠杆菌的身份。尽管这些蜱类作为夏菲氏大肠杆菌载体的作用仍未确定，该地区感染蜱的存在表明潜在的人畜共患风险。
