Detection of Ehrlichia phagocytophilaDNA in Ixodes ricinus Ticks from Areas in Switzerland Where  Tick-Borne Fever Is Endemic

A total of 1,523 adult Ixodes ricinus ticks were collected from regions where bovine ehrlichiosis is endemic and were examined for Ehrlichia phagocytophila via PCR. Of the ticks from cattle with ehrlichiosis, the ticks from healthy cattle, and the free-living ticks, 26.5% (18 of 68), 4.4% (35 of 802), and 0.8% (5 of 653), respectively, were positive.

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Natural Ehrlichia phagocytophila transmission coefficients from sheep ‘carriers’ to Ixodes ricinus ticks vary with the numbers of feeding ticks

Parasitology ◽

10.1017/s003118200100107x ◽

2002 ◽

Vol 124 (2) ◽

pp. 127-136 ◽

Cited By ~ 28

Author(s):

N. H. OGDEN ◽

A. N. J. CASEY ◽

N. P. FRENCH ◽

K. J. BOWN ◽

J. D. W. ADAMS ◽

...

Keyword(s):

Ixodes Ricinus ◽

Tick Infestation ◽

Infection Intensity ◽

Adult Tick ◽

Transmission Efficiency ◽

Infection Prevalence ◽

Direct Effects ◽

Transmission Coefficients ◽

Ehrlichia Phagocytophila ◽

Ixodes Ricinus Ticks

In a longitudinal study in a UK upland site, 38% of adult sheep were detected as infected with the tick-borne bacterium Ehrlichia phagocytophila by PCR of blood samples. Infection prevalence declined significantly with sheep age but varied significantly and non-linearly with the number of adult Ixodes ricinus ticks feeding per sheep. These findings suggested that under conditions of natural repeated tick-borne challenge sheep remain partially susceptible to re-infections, but the likelihood of re-infection depended on the numbers of feeding ticks. Transmission efficiency from sheep to immature ticks also varied significantly and non-linearly with the number of adult ticks feeding per sheep: transmission efficiency was almost zero in sheep with low adult tick infestations rising to 30% at certain levels of adult tick infestation. Infection intensity in infected engorged immature ticks also varied with the number of adult ticks feeding per sheep, but neither prevalence nor intensity of infection in engorged ticks were related to sheep blood PCR result. These findings suggest that variation in the numbers of ticks feeding per sheep may influence E. phagocytophila transmission by direct effects on transmission at the tick–host interface.

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Evidence of the Human Granulocytic Ehrlichiosis Agent in Ixodes ricinus Ticks in Switzerland

Journal of Clinical Microbiology ◽

10.1128/jcm.37.5.1332-1334.1999 ◽

1999 ◽

Vol 37 (5) ◽

pp. 1332-1334 ◽

Cited By ~ 24

Author(s):

Nicola Pusterla ◽

Christian M. Leutenegger ◽

Jon B. Huder ◽

Rainer Weber ◽

Ueli Braun ◽

...

Keyword(s):

Ixodes Ricinus ◽

Nucleotide Sequencing ◽

Rrna Gene ◽

Adult Males ◽

Granulocytic Ehrlichiosis ◽

Ehrlichia Phagocytophila ◽

Stage Of Development ◽

Human Granulocytic Ehrlichiosis ◽

Pcr Products ◽

Ixodes Ricinus Ticks

A total of 1,667 Ixodes ricinus ticks were collected from five regions in Switzerland where there have been sporadic occurrences of granulocytic ehrlichiosis in dogs and horses. The ticks were examined for rickettsiae of the Ehrlichia phagocytophila group via nested PCR. Twenty-one ticks (1.3%) were positive; 3 (0.5%) were nymphs, 6 (1.3%) were adult males, and 12 (1.9%) were adult females. The number of positive ticks varied with the stage of development and with the geographical origin. Nucleotide sequencing of the isolated PCR products identified these products as part of the 16S rRNA gene of Ehrlichia. In addition, these products had 100% homology with the agent of human granulocytic ehrlichiosis. The occurrence of this agent in I. ricinus in Switzerland presents a potential danger of transmission of granulocytic ehrlichiosis to dogs, horses, and humans.

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Detection of four Borrelia burgdorferi genospecies and first report of human granulocytic ehrlichiosis agent in Ixodes ricinus ticks collected in central Italy

Epidemiology and Infection ◽

10.1017/s0950268802007057 ◽

2002 ◽

Vol 129 (1) ◽

pp. 93-97 ◽

Cited By ~ 5

Author(s):

I. SANTINO ◽

M. DEL PIANO ◽

R. SESSA ◽

G. FAVIA ◽

A. IORI

Keyword(s):

Borrelia Burgdorferi ◽

Ixodes Ricinus ◽

Protected Area ◽

Central Italy ◽

First Report ◽

Granulocytic Ehrlichiosis ◽

Ehrlichia Phagocytophila ◽

Human Granulocytic Ehrlichiosis ◽

Ixodes Ricinus Ticks ◽

Male Tick

The presence of Borrelia burgdorferi s.l. and of Ehrlichia phagocytophila group was sought by PCR in Ixodes ricinus collected in a protected area of central Italy. Nymphs (n = 1475, gathered in 295 pools of 5 nymphs each) and adult ticks (n = 28) were examined. B. burgdorferi s.l. was detected in 13.8% of the nymph pools; of these, 63.4% were infected by B. valaisiana, 26.8% by B. afzelii, 7.3% by B. garinii, and 2.5% by B. burgdorferi s.s. Only a single adult male tick proved to host B. afzelii. The agent of human granulocytic ehrlichiosis (HGE) was detected in 2.7% of the nymph pools. Two HGE agent-positive nymph pools were also found to be positive for B. garinii and for B. afzelii, respectively. This is the first report from central Italy of the finding of the HGE agent in ticks.

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Field evidence for density-dependent facilitation amongst Ixodes ricinus ticks feeding on sheep

Parasitology ◽

10.1017/s0031182001001081 ◽

2002 ◽

Vol 124 (2) ◽

pp. 117-125 ◽

Cited By ~ 33

Author(s):

N. H. OGDEN ◽

A. N. J. CASEY ◽

N. P. FRENCH ◽

J. D. W. ADAMS ◽

Z. WOLDEHIWET

Keyword(s):

Ixodes Ricinus ◽

Adult Female ◽

Adult Tick ◽

Field Site ◽

Density Dependent ◽

Ehrlichia Phagocytophila ◽

Adult Females ◽

Field Evidence ◽

Ixodes Ricinus Ticks ◽

Tick Resistance

Engorged Ixodes ricinus nymphs collected from sheep resident in an upland UK field site were significantly lighter than nymphs that engorged on previously tick-naïve sheep, indicating that site-resident sheep continually exposed to ticks acquired anti-tick resistance. The weights of engorged nymphs that fed on naturally tick-resistant sheep increased significantly, however, when increasingly high numbers of adult female ticks fed on the sheep during seasonal peaks of tick activity. This relationship was unaffected by variations in nymph weight amongst individual sheep, between seasons and years, and potential effects of sheep infection with Ehrlichia phagocytophila; this suggests that high adult tick infestations may directly inhibit the expression of acquired anti-tick resistance by sheep. The length, width and weight of adult ticks and the scutum length of adult females were linearly related to their weight as an engorged nymph. The mean scutum length of adult female ticks feeding on sheep in the field site was greater than that of adult females obtained from engorged nymphs collected from sheep of the same site. This suggests that larger ticks have a survival advantage and that I. ricinus ticks exhibit density-dependent intraspecific facilitation at high infestation levels with potential consequences for the transmission of tick-borne diseases.

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Quantitative Real-Time PCR for Detection of Members of the Ehrlichia phagocytophila Genogroup in Host Animals and Ixodes ricinus Ticks

Journal of Clinical Microbiology ◽

10.1128/jcm.37.5.1329-1331.1999 ◽

1999 ◽

Vol 37 (5) ◽

pp. 1329-1331 ◽

Cited By ~ 51

Author(s):

Nicola Pusterla ◽

Jon B. Huder ◽

Christian M. Leutenegger ◽

Ueli Braun ◽

John E. Madigan ◽

...

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Ixodes Ricinus ◽

Nested Pcr ◽

Rrna Gene ◽

Granulocytic Ehrlichiosis ◽

Ehrlichia Phagocytophila ◽

Ixodes Ricinus Ticks ◽

Taqman Pcr ◽

The 16S Rrna Gene

A TaqMan PCR was established for identification and quantitation of members of the Ehrlichia phagocytophila group in experimentally infected cows and in Ixodes ricinus ticks. The TaqMan PCR identified a 106-bp section of the 16S rRNA gene by use of a specific fluorogenic probe and two primers. This technique was specific for members of the E. phagocytophila group, which include E. phagocytophila, Ehrlichia equi, and the agent of human granulocytic ehrlichiosis. The TaqMan system identified 10 copies of a cloned section of the 16S rRNA gene ofE. phagocytophila. The sensitivity and specificity of the TaqMan PCR were similar to those of conventional nested PCR. The numbers of ehrlichiae in leukocytes of the two cows experimentally infected with E. phagocytophila were measured daily by TaqMan PCR and had a course similar to that of the percentages of infected leukocytes determined daily by light microscopy. The prevalence of infected free-living ticks, which were collected from areas where bovine ehrlichiosis is endemic and from regions with sporadic occurrences of granulocytic ehrlichiosis in dogs and horses, was identical as determined by nested PCR and TaqMan PCR.

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TBE in Norway

Tick-borne encephalitis - The Book ◽

10.33442/978-981-14-0914-1_12b-24 ◽

2019 ◽

Author(s):

Katrine M. Paulsen ◽

Rose Vikse ◽

Arnulf Soleng ◽

Kristin S. Edgar ◽

Susanne Dudman ◽

...

Keyword(s):

Ixodes Ricinus ◽

Ixodes Ricinus Ticks

Ixodes ricinus ticks are mainly distributed along the Norwegian coastline from Østfold County in the southeast up approximately to 66°N in Nordland County.

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