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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

The impact of gene knock-down and vaccination against salivary metalloproteases on blood feeding and egg laying by Ixodes ricinus

Decrem, Yves ; Mariller, Marcel ; Lahaye, Kathia ; Blasioli, Virginie ; Beaufays, Jérôme ; Boudjeltia, Karim Zouaoui ; Vanhaeverbeek, Michel ; Cérutti, Martine ; Brossard, Michel ; Vanhamme, Luc ; Godfroid, Edmond

In: International Journal for Parasitology, 2008, vol. 38, no. 5, p. 549-560

Two cDNAs coding homologous putative metalloproteases (Metis 1 and Metis 2, expected molecular weights of 55.6 and 56.0 kDa, respectively) were identified from the hard tick Ixodes ricinus. The expression of Metis genes was induced in salivary glands during tick blood meal. RNA interference was used to assess the role of both Metis 1 and Metis 2 in tick feeding. It was found that salivary...

Université de Neuchâtel

Ecdysteroid titre and metabolism and cuticle deposition during embryogenesis of the ixodid tick Amblyomma hebraeum (Koch)

Dotson, Ellen Marie ; Connat, Jean-Louis ; Diehl, Peter A.

In: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 1995, vol. 110B, no. 1, p. 155-166

Three embryonic cuticles are formed before larval cuticle deposition during embryonic development of Amblyomma hebraeum. The quantity of radioimmunoassay-positive material varied between 50 and 200 pg ecdysone equivalents per mg, but no significant peaks were detected. Maternally incorporated [3H]-20-hydroxyecdysone and [3H]-ecdysone contained in freshly laid eggs...

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

Etude des facteurs déclenchant le comportement sexuel chez Ixodes ricinus L. et de la physiologie de ses sensilles gustatives

Grenacher, Stoyan ; Guérin, Patrick (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2002 ; 1646.

Abstract. Ticks are ectoparasites of vertebrates and utilize a variety of infochemicals for host finding and acceptance as well as for intraspecific aggregation and mating responses. Individual male and female Ixodes ricinus, the vector of Lyme disease in Europe, readily arrest on filter paper strips contaminated with their own faeces. I. ricinus also responds, but to a lesser degree, to...

Université de Neuchâtel

Behavioural and chemoreceptor cell responses of the tick, Ixodes ricinus, to its own faeces and faecal constituents

Grenacher, Stoyan ; Kröber, Thomas ; Guerin, Patrick M. ; Vlimant, Michèle

In: Experimental and Applied Acarology, 2001, vol. 25, no. 8, p. 641-660

Ticks are ectoparasites of vertebrates and utilize a variety ofinfochemicals for host finding and acceptance as well as for intraspecific aggregation and mating responses. Individual male and female Ixodes ricinus, the vector of Lyme disease in Europe, readily arrest onfilter paper strips contaminated with their own faeces. I. ricinus also responds, but to a lesser degree,...

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

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

Protective immunity against Ixodes ricinus induced by a salivary serpin

Prevot, Pierre-Paul ; Couvreur, B. ; Denis, V. ; Brossard, Michel ; Vanhamme, L. ; Godfroid, E.

In: Vaccine, 2007, vol. 25, no. 17, p. 3284-3292

Iris is a specific elastase inhibitor expressed in the salivary glands of the hard tick Ixodes ricinus. It belongs to the superfamily of serpins and interferes with both haemostasis and the immune response of the host. In this study, we first show that Iris is expressed in nymphs but not in the female midgut nor in males. We also show that Iris is present in the saliva. To examine its...