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Université de Neuchâtel

A standardised in vivo and in vitro test method for evaluating tick repellents

Kröber, Thomas ; Bourquin, Florence ; Guerin, Patrick M.

In: Pesticide Biochemistry and Physiology, 2013, vol. 107, no. 2, p. 160-168

The threat of transmission of Lyme borelliosis and tick-borne encephalitis by ixodid ticks has resulted in an increasing number of tick repellents coming onto the market. To allow proper evaluation of the efficacy of different types of compounds and their formulations, there is a need for standardised methods for testing ticks repellents. Ticks show a marked negative geotactic response following...

Université de Neuchâtel

Identification et caractérisation de protéines antigéniques de 'Borrelia burgdorferi' sensu lato

Wyss, Jean-Christophe ; Peter, Oliver (Dir.) ; Betschart, Bruno (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2012.

Borrelia afzelii, B. garinii, et B. burgdorferi sont trois des cinq espèces de Borrelia définitivement reconnues comme responsables de la borréliose de Lyme en Europe. Cette maladie infectieuse est transmise par les tiques et se caractérise par des symptômes multiples en plusieurs étapes touchant le derme, les articulations, le système neurologique et cardiaque....

Université de Neuchâtel

Perception of breath components by the tropical bont tick, Amblyomma variegatum Fabricius (Ixodidae) : I. CO2-excited and CO2-inhibited receptors

Steullet, Pascal ; Guerin, Patrick M.

In: Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology, 1992, vol. 170, no. 6, p. 665-676

Wall-pore olfactory sensilla located in the capsule of Haller's organ on the tarsus of Amblyomma variegatum ticks bear cells responding to vertebrate breath: one of these sensilla contains a CO2-excited receptor and a second sensillum has a CO2- inhibited receptor. Each of these antagonistic CO2-receptors, which display typical phasic-tonic responses,...

Université de Neuchâtel

Identification of vertebrate volatiles stimulating olfactory receptors on tarsus I of the tick Amblyomma variegatum Fabricius (Ixodidae) : I. Receptors within the Haller’s organ capsule

Steullet, Pascal ; Guerin, Patrick M.

In: Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology, 1994, vol. 174, no. 1, p. 27-38

Gas chromatography-coupled electrophysiological recordings (GC-EL) from olfactory sensilla within the capsule of Haller's organ of the tick Amblyomma variegatum indicate the presence of a number of stimulants in rabbit and bovine odours, and in steer skin wash. Some of these stimulants were fully identified by gas chromatography-mass spectrometry analysis and by matching...

Université de Neuchâtel

Identification of vertebrate volatiles stimulating olfactory receptors on tarsus I of the tick Amblyomma variegatum Fabricius (Ixodidae) : II. Receptors outside the Haller’s organ capsule

Steullet, Pascal ; Guerin, Patrick M.

In: Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology, 1994, vol. 174, no. 1, p. 39-47

Bovine odour excites olfactory receptor(s) in a wall-pore olfactory sensillum on the anterior pit of Haller's organ in Amblyomma variegatum. Gas chromatography-coupled electrophysiology recordings from this sensillum reveal the presence of 4 active compounds in bovine odour. The two strongest stimulants were identified as 2-nitrophenol and 4-methyl-2-nitrophenol by gas...

Université de Neuchâtel

Antiectoparasitic activity of the gum resin, gum haggar, from the East African plant, Commiphora holtziana

Birkett, Michael A. ; Al Abassi, Sate ; Kröber, Thomas ; Chamberlain, Keith ; Hooper, Antony M. ; Guerin, Patrick M. ; Pettersson, Jan ; Pickett, John A. ; Slade, Robin ; Wadhams, Lester J.

In: Phytochemistry, 2008, vol. 69, no. 8, p. 1710-1715

The mechanism of ixodid tick (Acari: Ixodidae) repellency by gum haggar, a resin produced by Commiphora holtziana (Burseraceae), was investigated by evaluating activity against the cattle tick, Boophilus microplus. In an arena bioassay, a hexane extract of the resin of C. holtziana exhibited a repellent effect lasting up to 5 h. The hydrocarbon fraction of the resin extract...

Université de Neuchâtel

Isolation of 2,6-dichlorophenol from the cattle tick Boophilus microplus: Receptor cell responses but no evidence for a behavioural response

de Bruyne, Marien ; Guerin, Patrick M.

In: Journal of Insect Physiology, 1994, vol. 40, no. 2, p. 143-154

2,6-Dichlorophenol, a compound known as a sex pheromone for several metastriate tick species, was isolated from different life-stages of the cattle tick Boophilus microplus. Receptor cells in two wall-pore single-walled sensilla on the tarsus I of male ticks responded to this compound in a dose-dependant manner. Using these receptors as specific detectors for compounds in the effluent of a...

Université de Neuchâtel

Responses of the tropical bont tick, Amblyomma variegatum (Fabricius), to its aggregation-attachment pheromone presented in an air stream on a servosphere

McMahon, Conor ; Guerin, Patrick M.

In: Journal of Comparative Physiology A, 2000, vol. 186, no. 1, p. 95-103

Male Amblyomma variegatum ticks feeding on a host release a mixture of o -nitrophenol and methyl salicylate which serves to attract conspecifics. The behavioural responses of A. variegatum on a servosphere to these volatiles presented in an air stream are detailed here. In still air, ticks walked on all eight legs, but with long halts. In contrast, the air stream caused continuous...

Université de Neuchâtel

Complementation of a Borrelia afzelii OspC mutant highlights the crucial role of OspC for dissemination of Borrelia afzelii in Ixodes ricinus

Fingerle, Volker ; Goettner, Gereon ; Gern, Lise ; Wilske, Bettina ; Schulte-Spechtel, Ulrike

In: International Journal of Medical Microbiology, 2007, vol. 297, no. 2, p. 97-107

Alteration of the outer surface protein (Osp) composition – especially that of OspA and OspC – seems to be important for the adaptation of Borrelia burgdorferi sensu lato to its endothermic hosts (mammals) and poikilothermic vectors (ticks). OspA possibly mediates adherence to tick midgut cells thus enabling the borreliae to survive in the vector, while OspC is associated with...

Université de Neuchâtel

Detection and identification of Borrelia burgdorferi sensu lato genospecies in ticks from three different regions in Slovakia

Smetanová, Katarína ; Burri, Caroline ; Pérez, David ; Gern, Lise ; Kocianova, Elena

In: Wiener Klinische Wochenschrift, 2007, vol. 19, no. 17-18, p. 534-537

Lyme borreliosis is one of the most common tick-borne diseases that occur in Slovakia. In this study, Borrelia burgdorferi sensu lato was detected and cultivated from questing ticks collected in three areas of Slovakia. Two methods, restriction fragment length polymorphism and reverse line blot, were used for identification of isolates and determination of the prevalence of B....