The molecular identity of fleas (Siphonaptera) carrying Rickettsia felis, Bartonella clarridgeiae and Bartonella rochalimae from dogs and cats in Northern Laos

Nichola E.D Calvani,Liam Bell,Abigail Carney,Carolina De La Fuente,Tori Stragliotto,Mikala Tunstall,Jan Šlapeta

doi:10.1016/j.heliyon.2020.e04385

Abstract

Cat fleas (Ctenocephalides felis) are the most commonly recognised ectoparasites of domestic pets globally and are frequently implicated in the transmission of a variety of zoonotic vector-borne pathogens. The aim of the present study was to investigate the morphological and molecular identity of fleas parasitising cats and dogs in Northern Laos and screen them for a range of bacterial pathogens. Fleas (n = 120) were collected from dogs and cats and morphologically identified as Ctenocephalides felis (115/120), Ctenocephalides orientis (4/120) and Pulex irritans (1/120). Molecular barcoding using the cytochrome c oxidase subunit I gene (cox1) was used to confirmed species identity of 21 selected fleas. The cat flea (C. felis) was the most dominant flea identified. Rickettsia and Bartonella spp. DNA was detected in 21/21 and 7/21 samples, respectively, via a multiplex real-time PCR targeting gltA and ssrA. Sequencing of the seven Bartonella-positive samples and ten Rickettsia-positive samples revealed Bartonella clarridgeiae, Bartonella rochalimae, Rickettsia felis and Rickettsia sp. genotype RF2125 DNA. Anaplasma platys DNA was detected in a single C. felis after 20 of the 21 DNA samples were screened using a commercial PCR panel for vector-borne pathogens. The detection of a range of bacterial pathogens in fleas from owned cats and dogs in Northern Laos provides further evidence to the importance of these ectoparasites as vectors of zoonotic diseases in the region.

Highlights

Fleas in the genus Ctenocephalides are agents of a variety of important zoonotic pathogens, including Rickettsia and Bartonella bacterial species (Eisen and Gage, 2012; Lawrence et al, 2019; Varagnol et al, 2009)
These vector-borne diseases are globally distributed and yet often overlooked in developing countries where access to medical care is limited. Such is the case in the Lao People's Democratic Republic where rickettsial infections have been identified in 27% of patients suffering from undifferentiated febrile illnesses, and where three molecularly-confirmed R. felis infections were documented between 2003-2011 (Dittrich et al, 2014; Phongmany et al, 2006)
Despite the human health implications, very little work has been conducted on the molecular identity of fleas and the pathogens they carry in Northern Laos, with previous studies relying on morphological identification alone (Kernif et al, 2012; Parola et al, 2003; Varagnol et al, 2009)

Summary

Introduction

Fleas in the genus Ctenocephalides are agents of a variety of important zoonotic pathogens, including Rickettsia and Bartonella bacterial species (Eisen and Gage, 2012; Lawrence et al, 2019; Varagnol et al, 2009). Rickettsia typhi and Rickettsia felis cause murine typhus and flea-borne spotted fever, respectively, and Bartonella henselae is responsible for cat scratch disease (Eisen and Gage, 2012; Kernif et al, 2012; Varagnol et al, 2009). These vector-borne diseases are globally distributed and yet often overlooked in developing countries where access to medical care is limited. Molecular barcoding of the cox gene provides a straightforward alternative that has been proven to unambigiously differentiate these species (Lawrence et al, 2019)

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Methods

Results