First sequence-confirmed detection of Ehrlichia minasensis in Rhipicephalus microplus from cattle in Costa Rica

Area of Science:

• Veterinary Microbiology
• Parasitology
• Molecular Diagnostics

Background:

• Ehrlichia minasensis is an emerging tick-borne bacterium affecting cattle.
• Previous reports exist in South America and Panama, but not Costa Rica.
• Rhipicephalus microplus is a significant cattle tick vector.

Purpose of the Study:

• To detect and confirm the presence of Ehrlichia minasensis in Costa Rican cattle ticks.
• To expand the known geographic distribution of E. minasensis.
• To provide sequence-confirmed evidence of E. minasensis in Central America.

Main Methods:

• Screening of 19 Rhipicephalus microplus ticks and 2 bovine blood samples from Costa Rica.
• Conventional PCR targeting Ehrlichia spp. groEL and dsb genes.
• DNA sequencing and phylogenetic analysis of positive amplicons.

Main Results:

• One adult female Rhipicephalus microplus tick tested positive for Ehrlichia spp. via groEL PCR.
• The obtained sequence showed 100% nucleotide identity with E. minasensis from Colombia.
• No amplification was observed in bovine blood samples or for the dsb target.

Conclusions:

• This study provides the first sequence-confirmed evidence of Ehrlichia minasensis in Rhipicephalus microplus ticks in Costa Rica.
• The findings expand the documented geographic range of E. minasensis in Central America.
• Further surveillance in cattle-tick systems is warranted.