New records of ticks (Acari: Ixodida) and Rickettsia species in El Salvador

Abstract

The tick fauna of El Salvador is currently represented by 10 species of hard ticks (family Ixodidae) and 2 species of soft ticks (family Argasidae). This study aimed to report new and additional records of ticks and rickettsiae in El Salvador. During 2019-2021, a total of 216 specimens of ticks were collected from eight host species (domestic and wild animals) and in the environment among 15 geographic localities of El Salvador. Combining morphological and molecular analyses, tick specimens were identified into the following 11 tick species: Amblyomma dissimile, Amblyomma longirostre, Amblyomma mixtum, Amblyomma ovale, Amblyomma cf. parvum, Amblyomma sabanerae, Amblyomma scutatum, Dermacentor panamensis, Ixodes boliviensis, Ornithodoros puertoricensis, and Otobius megnini. In addition, one free-living nymph was morphologically and molecularly identified as Ixodes sp., although closely related to Ixodes brunneus and Ixodes silvanus. Three rickettsial agents of the spotted fever group were identified: Rickettsia rhipicephali in D. panamensis; a Rickettsia endosymbiont in Ixodes boliviensis; and Rickettsia amblyommatis in A. cf. parvum. This study reports the first records of A. longirostre, D. panamensis, I. boliviensis, O. puertoricensis and O. megnini in El Salvador. In addition, the agents R. rhipicephali and Rickettsia sp. endosymbiont of I. boliviensis are also reported for the first time in the country. With the present study, the current tick fauna of El Salvador increases to 17 species, being 13 Ixodidae and 4 Argasidae, including the addition of one genus to each of these two families (Ixodes and Otobius, respectively).

Keywords: Amblyomma; Dermacentor; Ixodes; Ornithodoros; Otobius; Rickettsia rhipicephali.