Molecular detection and phylogenetic characterization of Ehrlichia- and Anaplasma-related genotypes in free-ranging anteaters from southeastern Brazil
摘要
Bacteria of the family Anaplasmataceae are tick-borne pathogens of recognized veterinary and zoonotic relevance, widely distributed among domestic and wild vertebrate hosts. Although increasingly reported in Brazilian wildlife species, molecular data on these agents in xenarthrans remain scarce, particularly in regions undergoing environmental transformation. This study investigated the occurrence of Anaplasma spp. and Ehrlichia spp. in free-ranging giant anteaters (Myrmecophaga tridactyla) and southern tamanduas (Tamandua tetradactyla) from the central-western region of São Paulo State, Brazil. Twenty-six blood samples (21 M. tridactyla and 5 T. tetradactyla) were analyzed using conventional and nested PCR assays targeting the 23 S rRNA gene (Anaplasma spp.) and the dsb gene (Ehrlichia spp.), followed by sequencing and phylogenetic inference. An Ehrlichia genotype phylogenetically related to Ehrlichia chaffeensis was detected in two M. tridactyla samples (7.69%), whereas an Anaplasma genotype was detected in one T. tetradactyla sample (3.85%). The Ehrlichia sequences showed high nucleotide identity (99.61–100%) with reference sequences identified as E. chaffeensis and grouped within clades containing E. chaffeensis in Maximum Likelihood analyses. The Anaplasma sequence showed phylogenetic affinity with a clade comprising Anaplasma marginale, Anaplasma centrale, and related genotypes. Because only partial gene fragments were analyzed, species-level assignment was not attempted. These findings provide molecular evidence of the occurrence of Anaplasmataceae-related genotypes in free-ranging xenarthrans inhabiting anthropogenically altered landscapes in southeastern Brazil. Further investigations including expanded sampling, vector identification, and multilocus or genomic approaches are necessary to better characterize these agents and clarify their ecological significance.