Molecular Detection of Rickettsia felis in Fleas of Companion Animals in East Texas

Abstract

Flea-borne spotted fever is an emerging insect-borne rickettsial infection caused by Rickettsia felis and has been identified worldwide. This study sought to explore the prevalence of rickettsiae associated with fleas on companion dogs and cats from Walker and Montgomery Counties in East Texas. Fleas were collected from animals entering local veterinary clinics for routine checkups. Collected fleas were identified as Ctenocephalides felis or Pulex irritans and analyzed by polymerase chain reaction for the presence of rickettsiae and subsequent sequencing. An estimation of the bcMLE (bias-corrected maximum likelihood estimation) of pooled samples was calculated. Four hundred eighty-eight fleas (comprising C. felis and P. irritans) were collected from 16 cats and 77 dogs. Our results demonstrate R. felis in 21 pools of fleas from dogs (bcMLE 15.28%) and a bcMLE of 7.25% from flea samples collected from cats. Sequence analysis revealed R. felis as the only Rickettsia that could be amplified in our samples using the rickettsial citrate synthase gene and subsequent sequencing. In this study, the presence of R. felis in fleas from companion cats and dogs suggests a potential risk of flea-borne spotted fever in humans who encounter flea-infested animals.

Cat Flea Coinfection with Rickettsia felis and Rickettsia typhi

“… b MIR = ([number of Rickettsia -positive pools/total fleas tested] × 100). c Karpathy et al ( 2009 ); d Nelson et al ( 2018 ); e Eremeeva et al ( 2012 ); f Abramowicz et al (2011); g Maina et al (2016); h Mullins et al ( 2018 ); i Abramowicz et al ( 2012 ); j Eremeeva et al ( 2008 ); k Noden et al ( 2017 ); l Blanton et al ( 2019 ); m Wang et al ( 2022 ); n Blanton et al ( 2016 ); o Brown et al ( 2022 ). MIR, minimum infection rate.…”

Molecular detection of Rickettsia felis in fleas and ticks collected from dogs and cats of Puebla, Mexico

“…Because of their hematophagous habits, they can generate intense itching in the host, which can lead to localized hair loss (alopecia) and secondary bacterial infections derived from licking (Rendle et al, 2021). Additionally, the transmission of bacterial and protozoan pathogens constitutes the most important role of these arthropods, highlighting the importance of the genus Rickettsia (Wang et al, 2022). Rickettsia genus encompasses pleomorphic bacteria that colonize the cytoplasm of vertebrate cells, having a tropism for the endothelial cells of small blood vessels (Kim, 2022).…”