Ehrlichia sp. infection in carthorses of low-income owners, Southern Brazil

Abstract

Although well established in dogs, Ehrlichia sp. infection has been scarcely reported in horses. The aim was to perform a comprehensive serological and molecular survey for the detection of Ehrlichia spp. in carthorses from Southern Brazil. Blood samples from 190 carthorses from Paraná State were sampled. Horses were also tested for Borrelia burgdorferi and Anaplasma phagocytophilum. Anti-Ehrlichia sp. antibodies were detected by a commercial rapid ELISA, and immunofluorescence antibody assays (IFA) with E. chaffeensis and E. canis as crude antigens. The molecular and phylogenetic analysis of Ehrlichia sp. was based on 16S rRNA and dsb genes. A total of 52 (27.4%), 4 (2.1%), and 3 (1.6%) horses were positive for Ehrlichia spp., Anaplasma spp. and Borrelia burgdorferi, respectively, by the commercial rapid ELISA. Thirty-eight (20.0%) and 37 (19.5%) horses showed anti-E. chaffeensis and anti-E. canis antibodies by IFA, respectively. One blood sample that also showed anti-E. chaffeensis antibodies was PCR positive for the 16S rRNA and dsb genes of Ehrlichia spp., showing an identity of>98.0% to the uncultured Ehrlichia sp. previously detected in Brazilian jaguars (Panthera onca). Anti-Ehrlichia sp. antibodies and Ehrlichia DNA were detected in carthorses from Southern Brazil, which may post public health concerns due to intimate contact with low-income owners. This is the first report of a natural infection of this bacteria in horses from South America. Clinical signs and the tick vector remain unknown.

Ticks, rickettsial and erlichial infection in small mammals from Atlantic forest remnants in northeastern Brazil

“… Sacchi et al (2012) reported Ehrlichia chaffeensis infecting marsh deer ( Blastocerus dichotomus ); however, its tick vector remains unknown in Brazil. In addition to these three Ehrlichia species, a number of novel ehrlichial genotypes have been recorded in Brazil, as for example, several phylogenetically closely related genotypes infecting jaguars ( Panthera onca ) ( Widmer et al, 2011 ), peccaries ( Tayassu pecari ) ( Soares et al, 2017 ), horses ( Vieira et al, 2016 ), crab-eating fox ( Cerdocyon thous ) ( Almeida et al, 2013 ), and sloth ( Bradypus tridactylus ) ( Soares et al, 2017 ).…”

Potentially Same Novel Ehrlichia Species in Horses in Nicaragua and Brazil

“…Similarly, Vieira and colleagues reported a potentially novel Ehrlichia sp. infecting horses in South America, with a high seroprevalence in carthorses; 1 horse blood sample was PCR positive for Ehrlichia 16S rDNA and dsb genes ( 2 ). Because these 2 studies sequenced different 16S rDNA regions, the Ehrlichia sp.…”

“…We retrieved an Ehrlichia PCR-positive horse blood sample ( 2 ) from Brazil and performed partial PCR and sequencing of the 16S rDNA, sodb , and groEL genes ( 1 ). Phylogenetic analysis of the sequences ( 3 – 5 ) demonstrated a close relationship between the Ehrlichia spp.…”

First Evidence of Ehrlichia minasensis Infection in Horses from Brazil

“…Despite studies on Ehrlichia infection in equine being scarce in Brazil, seropositivity to Ehrlichia antigens in horses was observed in the States of Paraná [20] and Mato Grosso [21], and the bacterial DNA was also detected in horses of Paraná [8]. Subsequent molecular surveys in Brazil suggest that the Brazilian isolate of Ehrlichia detected in horses may potentially belong to the same group as that detected in Nicaragua [5,22].…”

“…The genetic characterization of these Ehrlichial agents revealed their close relationship to E. ruminantium, which is an important pathogen of ruminants in Africa and the Caribbean [6], transmitted by ticks of the genus Amblyomma [7]. However, while Equine ehrlichiosis is present in Brazil [8], to date, there are no reports of E. ruminantium in Brazil [9]. Ehrlichia minasensis species has been detected in cattle [10], cervids [11] and several tick species within the genera Rhipicephalus [2,7,12,13], Amblyomma [13], Hyalomma [14,15], and Haemaphysalis [16].…”