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After the previous description and characterization of Theileria equi sensu stricto (Genotype A) in Argentina, the aim of the present study was to investigate the possible heterogeneity of 18 S rDNA genotypes circulating in this country. Therefore, blood samples from 18 horses from two different neighborhoods of Corrientes City, Corrientes Province, were analyzed for infection with Theileria species. Theileria DNA was detected in five samples (27.8%). Four nearly complete 18 S rDNA gene sequences were obtained and phylogenetic analyses were carried out. The maximum likelihood tree constructed in this study revealed that two different 18 S rDNA genotypes - namely Genotype A (T. equi sensu stricto) and Genotype C (T. equi sensu lato/Theileria haneyi) - are circulating in the same horse population. These results represent to first evidence of T. equi genotype heterogeneity in Argentina and also the first detection of a member of the T. haneyi/Genotype C group. Together with reports from Brazil, the results of this study reinforce the assumption that Genotypes A and C are the predominant genotypes in South America. [ABSTRACT FROM AUTHOR]

The aim of this study was to report the first detection of Candidatus Ehrlichia pampeana in Haemaphysalis juxtakochi from Argentina. Free-living ticks were collected from vegetation by drag-flag method on five sample sites in Entre Ríos Province, central Argentina, belonging to the Espinal Phytogeographic Province. Molecular detection of order Rickettsiales agents was performed using gltA (Rickettsia spp.), 16 S rRNA and groEL (Anaplasmataceae) genes as targets. A total of 67 ticks of Amblyomma aureolatum (20 nymphs and 4 adults), Amblyomma dubitatum (15 nymphs) and Haemaphysalis juxtakochi (24 nymphs and 4 adults) were collected. While all tested ticks were negative for Rickettsia spp., and Anaplasmataceae agents could neither be detected in A. aureolatum nor in A. dubitatum, Candidatus Ehrlichia pampeana was detected in one male of H. juxtakochi. DNA sequences of this microorganism (16 S rDNA and groEL) are related to sequences of Ehrlichia ewingii. The findings of the current study represent the first report of this Ehrlichia strain for Argentina. [ABSTRACT FROM AUTHOR]

The aim of this work is to report the first detection of Procyon cancrivorus naturally co-infected with Hepatozoon sp. cf. H. procyonis and a novel Anaplasma strain from South America and potential vector tick species associated. On August 30, 2016, a specimen of P. cancrivorus was found dead on the route in Chaco province, Argentina. A tick and a blood sample by cardiac puncture was collected from the specimen. DNA was extracted from blood sample and the tick was morphological identity as a female of Amblyomma ovale. Molecular detection of Anaplasmataceae family and Hepatozoon spp. agents was performed targeting two different loci: 16 S rRNA and 18 S rRNA gene. The phylogenetic analyses show that the Anaplasma sp. strain detected in P. cancrivorus in this study is similar to Anaplasma sp. strains previously detected in Nasua nasua and A. ovale from Brazil. Furthermore, Hepatozoon sp. of the H. procyonis group was amplified that is phylogenetically closely related to H. procyonis reported in N. nasua from Brazil. Since it was not exactly the same as the latter, it was decided to name at Hepatozoon sp. cf. H. procyonis. It is possible that, this potential new species of Anaplasma would be specific for Procyonidae family and there are two species of Hepatozoon linked to this family in South America. These results added to other published studies suggest that A. ovale could be a potential vector both for the new potential strain of Anaplasma and for the Hepatazoon sp. of the H. procyonis group. [ABSTRACT FROM AUTHOR]

After the previous description and characterization of Theileria equi sensu stricto (Genotype A) in Argentina, the aim of the present study was to investigate the possible heterogeneity of 18 S rDNA genotypes circulating in this country. Therefore, blood samples from 18 horses from two different neighborhoods of Corrientes City, Corrientes Province, were analyzed for infection with Theileria species. Theileria DNA was detected in five samples (27.8%). Four nearly complete 18 S rDNA gene sequences were obtained and phylogenetic analyses were carried out. The maximum likelihood tree constructed in this study revealed that two different 18 S rDNA genotypes - namely Genotype A (T. equi sensu stricto) and Genotype C (T. equi sensu lato/Theileria haneyi) - are circulating in the same horse population. These results represent to first evidence of T. equi genotype heterogeneity in Argentina and also the first detection of a member of the T. haneyi/Genotype C group. Together with reports from Brazil, the results of this study reinforce the assumption that Genotypes A and C are the predominant genotypes in South America., Competing Interests: Declarations. Ethical approval: The study protocol was approved by the Animal Ethical Commission of the CICUAE-CERSAN of Instituto Nacional de Tecnología Agropecuaria (protocol no. P19-0010). Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)