Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela, and Consejo Nacional de Investigaciones Científicas y Técnicas, CC 22, CP 2300, Rafaela, Santa Fe, Argentina.
Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Universidad Nacional del Litoral, and Consejo Nacional de Investigaciones Científicas y Técnicas, CP 3080, Esperanza, Santa Fe, Argentina.
Acta Trop. 2020 Oct;210:105588. doi: 10.1016/j.actatropica.2020.105588. Epub 2020 Jun 15.
To obtain information about rickettsial bacteria in ticks of the genus Ixodes from Argentina and Uruguay, specimens of I. fuscipes (previously named as I. aragaoi), Ixodes pararicinus, Ixodes sp. cf. I. affinis, and Ixodes sp. were tested targeting the rickettsial gltA and ompA genes. Rickettsial bacteria was detected in all of these species. Rickettsia found in Ixodes sp. is closely related to Ca. Rickettsia mendelii, which was previously detected in I. ricinus of the Czech Republic and later in I. brunneus from the USA. Phylogenetic analyses of the Rickettsia strains found in I. fuscipes, I. pararicinus, and Ixodes sp. cf. I. affinis showed that these strains form a clade together with R. buchneri detected in I. scapularis from the USA, which is closely related to R. monacensis from Europe. Rickettsia buchneri, R. cooleyi and the Rickettsia detected in I. fuscipes, I. pararicinus, and Ixodes sp. cf. I. affinis clustered together in a clade well supported, which suggest that they are different strains of R. buchneri. The phylogenetic analysis shows that Ixodes ticks that are closely related in evolutionary terms (i.e. Ixodes species from the I. ricinus complex, I. brunneus-Ixodes sp.) share closely related rickettsial strains. The results of this study show that rickettsial bacteria are present in Ixodes ticks from Argentina and describe the first detection of Ca. R. mendelii in South America.
为了获取阿根廷和乌拉圭的恙螨属（Ixodes）蜱中有关立克次体细菌的信息，对 I. fuscipes（以前称为 I. aragaoi）、Ixodes pararicinus、Ixodes sp. cf. I. affinis 和 Ixodes sp. 进行了检测，目标是立克次体 gltA 和 ompA 基因。在所有这些物种中都检测到了立克次体细菌。在 Ixodes sp. 中发现的立克次体与以前在捷克共和国的 I. ricinus 中发现的 Ca. Rickettsia mendelii 密切相关，后来在美国的 I. brunneus 中也发现了该种。对在 I. fuscipes、I. pararicinus 和 Ixodes sp. cf. I. affinis 中发现的立克次体菌株的系统发育分析表明，这些菌株与在美国的 I. scapularis 中发现的 R. buchneri 一起形成一个分支，与欧洲的 R. monacensis 密切相关。R. buchneri、R. cooleyi 和在 I. fuscipes、I. pararicinus 和 Ixodes sp. cf. I. affinis 中检测到的立克次体在一个支持度很高的分支中聚集在一起，这表明它们是不同的 R. buchneri 菌株。系统发育分析表明，在进化上密切相关的恙螨（即 I. ricinus 复合体中的 Ixodes 物种、I. brunneus-Ixodes sp.）共享密切相关的立克次体菌株。本研究结果表明，阿根廷的恙螨中存在立克次体细菌，并描述了在南美洲首次检测到 Ca. R. mendelii。
