Prevalence of rickettsias in ticks (Acari: Ixodidae) collected in domestic animals of the northern region of Caldas department, Colombia

Abstract

The northern region of the Caldas department in Colombia is considered an endemic area for murine typhus. Recent studies in patients with acute febrile disease demonstrated infection with the spotted fever group’s rickettsiae due to an increase in the IgG titer by indirect immunofluorescence in paired sera obtained from these patients. The objective of the current research was to identify the species of ticks present in domestic animals in the northern region of Caldas and establish the presence of rickettsial genomic material in the collected ticks. Ticks were obtained from bovines, horses, and dogs in seven municipalities in the north of Caldas. Ticks were stored in 90 % ethanol until processing and were identified using taxonomic keys, DNA was extracted using commercial techniques, and the gltA gene was amplified by conventional chain reaction polymerase (PCR). Seven hundred thirteen ticks were obtained from 593 domestic animals. The highest infestation occurred in cattle, followed by canines and horses. Ticks found corresponded to the species Riphicephalus microplus, Dermacentor nitens, Amblyomma sp., and Riphicephalus sanguineus s.l. In none of the tick samples, Rickettsia-specific gltA gene DNA was found. It can be inferred that the ticks obtained are not a source of rickettsial infection for people in this department region, despite finding different species associated with the transmission of this disease.