Tick-borne pathogen detection in midgut and salivary glands of adult Ixodes ricinus

Various ticks exist in the temperate hilly and pre-alpine areas of Northern Italy, where Ixodes ricinus is the more important. In this area different tick-borne pathogen monitoring projects have recently been implemented; we present here the results of a twoyear field survey of ticks and associated pathogens, conducted 2009-2010 in North-eastern Italy. The cost-effectiveness of different sampling strategies, hypothesized a posteriori based on two sub-sets of data, were compared and analysed. The same two subsets were also used to develop models of habitat suitability, using a maximum entropy algorithm based on remotely sensed data. Comparison of the two strategies (in terms of number of ticks collected, rates of pathogen detection and model accuracy) indicated that monitoring at many temporary sites was more cost-effective than monthly samplings at a few permanent sites. The two model predictions were similar and provided a greater understanding of ecological requirements of I. ricinus in the study area. Dense vegetation cover, as measured by the normalized difference vegetation index, was identified as a good predictor of tick presence, whereas high summer temperatures appeared to be a limiting factor. The study suggests that it is possible to obtain realistic results (in terms of pathogens detection and development of habitat suitability maps) with a relatively limited sampling effort and a wellplanned monitoring strategy.

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Putative morphology of Neoehrlichia mikurensis in salivary glands of Ixodes ricinus

Scientific Reports ◽

10.1038/s41598-020-72953-0 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Jaroslav Ondruš ◽

Pavel Kulich ◽

Oldřich Sychra ◽

Pavel Široký

Keyword(s):

Salivary Glands ◽

Ixodes Ricinus ◽

Mammalian Cells ◽

Intracellular Pathogen ◽

Transmission Electron ◽

Ultrathin Sections ◽

In Vitro Feeding ◽

Neoehrlichia Mikurensis ◽

Electron Lucent

Abstract Neoehrlichia mikurensis is an emerging tick-borne intracellular pathogen causing neoehrlichiosis. Its putative morphology was described in mammalian, but not in tick cells. In this study, we aim to show the presumptive morphology of N. mikurensis in salivary glands of engorged females of Ixodes ricinus. To accomplish this, we collected I. ricinus ticks in a locality with a high N. mikurensis prevalence, allowed them to feed in the artificial in vitro feeding system, dissected salivary glands and screened them by PCR for N. mikurensis and related bacteria. Ultrathin sections of salivary glands positive for N. mikurensis but negative for other pathogens were prepared and examined by transmission electron microscopy. We observed two individual organisms strongly resembling N. mikurensis in mammalian cells as described previously. Both bacteria were of ovoid shape between 0.5–0.8 μm surrounded by the inner cytoplasmic and the rippled outer membrane separated by an irregular electron-lucent periplasmic space. Detection of N. mikurensis in salivary glands of I. ricinus suggests that this bacterium uses the “salivary pathway of transmission” to infect mammals.

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Detection of tick-borne pathogens in questing Ixodes ricinus in the French Pyrenees and first identification of Rickettsia monacensis in France

Parasite ◽

10.1051/parasite/2019019 ◽

2019 ◽

Vol 26 ◽

pp. 20 ◽

Cited By ~ 2

Author(s):

Toufic Akl ◽

Gilles Bourgoin ◽

Marie-Line Souq ◽

Joël Appolinaire ◽

Marie-Thérèse Poirel ◽

...

Keyword(s):

Ixodes Ricinus ◽

Pathogen Detection ◽

Spotted Fever ◽

Spotted Fever Group ◽

Rupicapra Pyrenaica ◽

Rickettsia Monacensis ◽

Animal Pathogens ◽

Questing Ticks ◽

Pyrenean Chamois ◽

First Time

Ticks are important vectors of several human and animal pathogens. In this study, we estimated the prevalence of important tick-borne infections in questing ticks from an area in Southwestern France (Hautes-Pyrénées) inhabited by Pyrenean chamois (Rupicapra pyrenaica pyrenaica) experiencing high tick burden. We examined adult and nymph ticks collected by the flag dragging method from 8 to 15 sites in the Pic de Bazès during the years 2009, 2011, 2013 and 2015. PCR assays were conducted on selected ticks for the detection of Borrelia burgdorferi s.l., Babesia spp., Rickettsia spp., spotted fever group (SFG) Rickettsia and Anaplasma phagocytophilum. Randomly selected positive samples were submitted for sequence analysis. A total of 1971 questing ticks were collected including 95 males, 101 females and 1775 nymphs. All collected ticks were identified as Ixodes ricinus. Among them, 696 ticks were selected for pathogen detection and overall prevalence was 8.4% for B. burgdorferi s.l.; 0.4% for Babesia spp.; 6.1% for A. phagocytophilum; 17.6% for Rickettsia spp.; and 8.1% for SFG Rickettsia. Among the sequenced pathogens, we detected in this population of ticks the presence of Babesia sp. EU1 and Rickettsia helvetica, as well as Rickettsia monacensis for the first time in France. The detection of these pathogens in the Pic de Bazès highlights the potential infection risks for visitors to this area and the Pyrenean chamois population.

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Development of the salivary glands in embryos of Ixodes ricinus (Acari: Ixodidae)

Experimental and Applied Acarology ◽

10.1023/b:appa.0000021805.51307.37 ◽

2004 ◽

Vol 32 (3) ◽

pp. 219-230 ◽

Cited By ~ 4

Author(s):

Krzysztof Jasik ◽

Alicja Buczek

Keyword(s):

Salivary Glands ◽

Ixodes Ricinus

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A family of putative metalloproteases in the salivary glands of the tick Ixodes ricinus

FEBS Journal ◽

10.1111/j.1742-4658.2008.06308.x ◽

2008 ◽

Vol 275 (7) ◽

pp. 1485-1499 ◽

Cited By ~ 37

Author(s):

Yves Decrem ◽

Jérôme Beaufays ◽

Virginie Blasioli ◽

Kathia Lahaye ◽

Michel Brossard ◽

...

Keyword(s):

Salivary Glands ◽

Ixodes Ricinus

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Exploring the messages of the salivary glands of Ixodes ricinus.

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.2002.66.223 ◽

2002 ◽

Vol 66 (3) ◽

pp. 223-224 ◽

Cited By ~ 8

Author(s):

Jesus G Valenzuela

Keyword(s):

Salivary Glands ◽

Ixodes Ricinus

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Hosts and Pathogen Detection for Immature Stages of Ixodes ricinus (Acari: Ixodidae) in North-Central Spain

Experimental and Applied Acarology ◽

10.1007/s10493-005-3271-6 ◽

2005 ◽

Vol 37 (3-4) ◽

pp. 257-268 ◽

Cited By ~ 42

Author(s):

A. Estrada-Peña ◽

J. J. Osácar ◽

B. Pichon ◽

J. S. Gray

Keyword(s):

Ixodes Ricinus ◽

Pathogen Detection ◽

Immature Stages ◽

Central Spain ◽

North Central

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Tick-borne pathogen detection in midgut and salivary glands of adult Ixodes ricinus

10.1101/489328 ◽

2018 ◽

Cited By ~ 1

Author(s):

Emilie Lejal ◽

Sara Moutailler ◽

Ladislav Simo ◽

Muriel Vayssier-Taussat ◽

Thomas Pollet

Keyword(s):

Salivary Glands ◽

Blood Meal ◽

Pathogen Detection ◽

Pathogen Transmission ◽

Borrelia Miyamotoi ◽

Rickettsia Felis ◽

Disease Epidemiology ◽

Borrelia Lusitaniae ◽

Males And Females ◽

Tick Midgut

Background: Tick midgut and salivary glands represent the primary organs for pathogen acquisition and transmission, respectively. Specifically, the midgut is the first organ to have contact with pathogens during the blood meal uptake, while salivary glands along with their secretions play a crucial role in pathogen transmission to the host. Currently there is little data about pathogen composition and prevalences in I. ricinus midgut and salivary glands. The present study investigated the presence of 32 pathogen species in the midgut and salivary glands of unfed I. ricinus males and females using high-throughput microfluidic real-time PCR. Such an approach is important for enriching the knowledge about pathogen distribution in distinct tick organs which should lead to a better understanding I. ricinus-borne disease epidemiology. Results: Borrelia lusitaniae, Borrelia spielmanii, and Borrelia garinii, were detected in both midgut and salivary glands suggesting that the migration of these pathogens between these two organs might not be triggered by the blood meal. In contrast, Borrelia afzelii was detected only in the tick midgut. Anaplasma phagocytophilum and Rickettsia helvetica were the most frequently detected in ticks and were found in both males and females in the midgut and salivary glands. In contrast, Rickettsia felis was only detected in salivary glands. Finally Borrelia miyamotoi and Babesia venatorum were detected only in males in both midgut and salivary glands. Among all collected ticks, between 10 and 21% of organs were co-infected. The most common bacterial co-infections in male and female midgut and salivary glands was R. helvetica/A. phagocytophilum and R. helvetica/B. lusitaniae respectively. Conclusions: Analysing tick-borne pathogen (TBP) presence in specific tick organs enabled us to (i) highlight contrasting results with well-established transmission mechanism postulates, (ii) venture new hypotheses concerning pathogen location and migration from midgut to salivary glands, and (iii) suggest other potential associations between pathogens not previously detected at the scale of the whole tick. This work highlights the importance of considering all tick scales (i.e. whole ticks vs organs) to study TBP ecology and represents another step towards improved understanding of TBP transmission.

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