Candidatus Neoehrlichia mikurensis in rodents in an area with sympatric existence of the hard ticks Ixodes ricinus and Dermacentor reticulatus, Germany

Abstract

BackgroundCandidatus Neoehrlichia mikurensis (CNM) has been described in the hard tick Ixodes ricinus and rodents as well as in some severe cases of human disease. The aims of this study were to identify DNA of CNM in small mammals, the ticks parasitizing them and questing ticks in areas with sympatric existence of Ixodes ricinus and Dermacentor reticulatus in Germany.MethodsBlood, transudate and organ samples (spleen, kidney, liver, skin) of 91 small mammals and host-attached ticks from altogether 50 small mammals as well as questing I. ricinus ticks (n=782) were screened with a real-time PCR for DNA of CNM.Results52.7% of the small mammals were positive for CNM-DNA. The majority of the infected animals were yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus). Small mammals with tick infestation were more often infected with CNM than small mammals without ticks. Compared with the prevalence of ~25% in the questing I. ricinus ticks, twice the prevalence in the rodents provides evidence for their role as reservoir hosts for CNM.ConclusionThe high prevalence of this pathogen in the investigated areas in both rodents and ticks points towards the need for more specific investigation on its role as a human pathogen.

Neoehrlichiosis: an emerging tick-borne zoonosis caused by Candidatus Neoehrlichia mikurensis

“…Studies investigating rodents as well as questing ticks showed that prevalences in rodents were about 2-10 9 higher than in ticks (Obiegala et al 2014;Silaghi et al 2012). A reservoir function of rodents seems highly likely and was indeed proven in recent xenodiagnostic studies (Burri et al 2014).…”

“…It seems that insectivores do not play a role in the transmission or maintenance of Ca. N. mikurensis as so far none of the investigated insectivores were positive in Germany, Sweden and The Netherlands (Andersson and Raberg 2011;Jahfari et al 2012;Silaghi et al 2012).…”

Infections with the tick-borne bacterium Candidatus Neoehrlichia mikurensis

“…It has been detected in Mongolia [12], China [6,12,13], Japan [1,14], Russia [4,5,15,16], the Czech Republic [9,17,18], Slovakia [19][20][21], Moldova [22], Hungary [23][24][25], Austria [18,26], Germany [11,[27][28][29][30][31][32], Switzerland [33][34][35][36][37], Poland [38,39], Romania [40], France [28,41,42], Belgium [43], Italy [44][45][46], Spain [47], The Netherlands [3,42,43,48], and the Scandinavian countries [2,…”

Molecular phylogeography of tick-borne encephalitis virus in central Europe

“…I. ricinus and Dermacentor reticulatus have been shown to occur sympatrically (Silaghi et al, 2012), and the latter is currently spreading from east to west along river valleys in Poland and from south to north along the corridor of the Dyje and Morava rivers in the Czech Republic (Široký et al, 2011;Zygner et al, 2009). The Morava flows to the south, directly passing TBEV isolation sites at Zahorska Ves and Malacky in Slovakia to meet the Danube.…”