Absence of zoonotic Bartonella species in questing ticks: First detection of Bartonella clarridgeiae and Rickettsia felis in cat fleas in the Netherlands

Ellen Tijsse-Klasen,Willem Takken,Ard M Nijhof,Hein Sprong,Paul Am Overgaauw,Frans Jongejan,Manoj Fonville,Johan R Reimerink,Fedor Gassner,Emil Ke Hovius

doi:10.1186/1756-3305-4-61

Abstract

BackgroundAwareness for flea- and tick-borne infections has grown in recent years and the range of microorganisms associated with these ectoparasites is rising. Bartonella henselae, the causative agent of Cat Scratch Disease, and other Bartonella species have been reported in fleas and ticks. The role of Ixodes ricinus ticks in the natural cycle of Bartonella spp. and the transmission of these bacteria to humans is unclear. Rickettsia spp. have also been reported from as well ticks as also from fleas. However, to date no flea-borne Rickettsia spp. were reported from the Netherlands. Here, the presence of Bartonellaceae and Rickettsiae in ectoparasites was investigated using molecular detection and identification on part of the gltA- and 16S rRNA-genes.ResultsThe zoonotic Bartonella clarridgeiae and Rickettsia felis were detected for the first time in Dutch cat fleas. B. henselae was found in cat fleas and B. schoenbuchensis in ticks and keds feeding on deer. Two Bartonella species, previously identified in rodents, were found in wild mice and their fleas. However, none of these microorganisms were found in 1719 questing Ixodes ricinus ticks. Notably, the gltA gene amplified from DNA lysates of approximately 10% of the questing nymph and adult ticks was similar to that of an uncultured Bartonella-related species found in other hard tick species. The gltA gene of this Bartonella-related species was also detected in questing larvae for which a 16S rRNA gene PCR also tested positive for "Candidatus Midichloria mitochondrii". The gltA-gene of the Bartonella-related species found in I. ricinus may therefore be from this endosymbiont.ConclusionsWe conclude that the risk of acquiring Cat Scratch Disease or a related bartonellosis from questing ticks in the Netherlands is negligible. On the other hand fleas and deer keds are probable vectors for associated Bartonella species between animals and might also transmit Bartonella spp. to humans.

Highlights

Awareness for flea- and tick-borne infections has grown in recent years and the range of microorganisms associated with these ectoparasites is rising
The domestic cat is the major reservoir of Bartonella henselae, with a confirmed link to disease in humans [13,14]
Vegetation ticks To investigate the presence of Bartonella henselae in the Dutch tick population 1527 Ixodes ricinus nymphal and adult ticks from 16 geographically different locations were collected from recent field studies (Table 1)

Summary

Introduction

Awareness for flea- and tick-borne infections has grown in recent years and the range of microorganisms associated with these ectoparasites is rising. Bartonella henselae, the causative agent of Cat Scratch Disease, and other Bartonella species have been reported in fleas and ticks. The role of Ixodes ricinus ticks in the natural cycle of Bartonella spp. and the transmission of these bacteria to humans is unclear. Rickettsia spp. have been reported from as well ticks as from fleas. Cat-scratch disease (CSD) is probably the most common Bartonella infection in the northern hemisphere [1,2]. The domestic cat is the major reservoir of Bartonella henselae, with a confirmed link to disease in humans [13,14]. Ctenocephalides felis, are involved in transmission between cats and may be able to transmit B. henselae to humans: Approximately 30% of patients with CSD do not recall traumatic cat contact [17,18,19]. There are only few reports of disease cases linked to these species [20,21,22,23]

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