Molecular Evidence of Rickettsia felis in Phereoeca sp.

Abstract

Rickettsia felis is an obligate intracellular bacterium capable of infecting ticks, fleas, lice, and other arthropods. This bacterium is classified as a member of the Transitional Group (TRG) Rickettsia. It is known the evidence of R. felis mutualistic and obligatory relationship with some eukaryote organisms. However, there aren’t scientific accounts of R. felis and moths of the order Lepidoptera association. The current work reports the first identification of the bacteria R. felis in Phereoeca sp. For that, a polymerase chain reaction (PCR) assay using gltA, ompA, and ompB genes was used. The nucleotide sequences showed 100% of identity with other Rickettsia felis sequences. The genus-level identification of the moth larvae was performed by morphological taxonomic keys and PCR analysis of the cytochrome oxidase I (COI) gene. The nucleotide sequenced showed 94.94% similarity with the species Phereoeca praecox. However, with the low number of sequences deposited in the databases, the species was classified as Phereoeca sp. The results suggest that R. felis may develop in an organism without blood-feeding behavior (Lepidoptera), as it has been demonstrated for booklice (Psocoptera). Further investigation is necessary in order to confirm pathogenic or mutualistic association with moths.

Is vertical transmission the only pathway for Rickettsia felis ?

“…Rickettsia felis is the first agent described within the Transitional group in 1990 and has been isolated from the cat flea Ctenocephalides felis felis in Africa (Caravedo Martinez et al., 2021). This species represents a particular case because it has been detected using molecular methods in a wide range of arthropods, among which hematophagous groups, such as fleas and mosquitoes, stand out, as well as free‐living groups, such as booklice (Psocodea) and moths (Lepidoptera) (Behar et al., 2010; Brown & Macaluso, 2016; de Araújo et al., 2021; Parola et al., 2016).…”