Fleas in wild mammals: first records of Ctenocephalides felis-Rickettsia felis complex in Patagonia

WINTER, M.; ABATE, S.; ACOSTA D.B.; SANCHEZ J. P.

La Plata

Congreso; II Congress of the Latin American Society for Vector Ecology, Control of endemic zoonotic and vector-borne emerging and re-emerging diseases: Current challenges in Latin America; 2022

Adult fleas (Insecta: Siphonaptera) are blood-sucking parasites of birds and mammals. Alsothey are known as vectors of several pathogens of important diseases in animals andhumans. The aim of this study was to evaluate the diversity of fleas and the presence ofRickettsia spp. in wild native mammals to the extreme northeast of Río Negro province,Argentine Patagonia. Between 2020 and 2021 fleas were collected from 12 hosts of fourorders and five species. Order Didelphimorphia: three white-eared opossum (Didelphisalbiventris), order Cingulata: two big hairly armadillo (Chaetophractus villosus), orderCarnivora: three south american grey fox (Lycalopex gymnocercus) and one geoffroy's cat(Leopardus geoffroyi) and order Rodentia: three plains vizcacha (Lagostomus maximus).The animals were found lifeless due to being run over. They were immediately placed in awhite polyethylene bag to facilitate the collection of fleas. A total of 154 fleas were recoveredthat were preserved in 96% alcohol. Total genomic DNA was extracted from 26 fleascollected in the 12 infested mammals using the Chelex resin protocol. The presence ofRickettsia was screened using conventional PCR for three gene fragments, gltA (610 bp),ompB (650 bp) and ompA (580 bp). The following associations (host-flea) were identified: L.maximus - C. felis, L. geoffroyi- C. felis, L. geoffroyi- Pulex irritans, L. gymnocercus- P.irritans, L. maximus- P. irritans, L. maximus- Hectopsylla sp., C. villosus- Phthiropsyllaagenoris. Also, a Rickettsial bacterium was detected in a single flea sample, C. felis,collected from a female synanthropic white-eared opossum. The nBLAST analysis of thethree gene fragments in the positive sample showed identity 100% with R. felis. This studycontributes to knowledge of the biodiversity from Patagonia and provides novel informationabout flea-pathogen associations in wildlife and represents the first records of C. felis- R.felis complex in Patagonia. Also, there is the first record of L. geoffroyi as host of C. felis andP. irritans. R. felis (causative agent of flea-borne spotted fever) is one of the emerginghuman rickettsiosis agents worldwide. This result suggests the need to replicate andincrease this type of studies in the wild fauna of Patagonia in order to determine the possiblepresence of an epidemiological network implicated in the circulation, transmission, and themaintain of R. felis in wild animals and their fleas.