RESUMEN
Acaricide resistance of the cattle tick Rhipicephalus (Boophilus) microplus is widespread in most of the countries where this parasite is present. Bioassays are used to diagnose the level and pattern of resistance in tick populations. In the present study, we describe a detailed protocol of the Larval Tarsal Test (LTT) using simplified equipment and data on the resistance of 17 tick field populations originating from 5 Brazilian states. Nine acaricidal compounds from 5 major classes were tested: organophosphates (OP), synthetic pyrethroids (SP), macrocyclic lactones (ML), phenylpyrazols (PYZ) and amidines. For comparison, four of the tick populations were also tested with the Larval Packet Test (LPT) with one compound per class. The most common resistances were to SP, amitraz and OP, with frequencies of 94%, 88% and 82%, respectively. Resistance to PYZ was also found to be widespread (65%), suggesting a rapid development of fipronil resistance in Brazil. One case of ML resistance and 2 cases of suspected ML resistance were identified with the LTT. The LTT led to higher resistance ratios to all compounds than the LPT, reflecting its high sensitivity to detect resistance. Finally, the LTT allowed testing a larger number of compounds and doses with reduced labour in comparison to the LPT and turned out to be a reliable bioassay to detect resistance in field populations.
Asunto(s)
Acaricidas/farmacología , Rhipicephalus/efectos de los fármacos , Animales , Brasil , Resistencia a los Insecticidas , Larva/efectos de los fármacos , Dosificación Letal Mediana , Análisis de SupervivenciaRESUMEN
La diathese homeopathique est une notion actuellement controversee par certains courants et ecoles homeopathiques. Apres une longue pratique des "profils protidiques" l'auteur emet l'hypothese que les proteines plasmatiques sont peut-etre un des reflets de ce "mode reactionnel individuel" decrit par les homeopathes. Dans une vision globale plus philosophique que scientifique, cette etude fait remarquer que l'on peut comparer deux systemes au depart tres differents: d'un cote le "profil protidique" construit avec des parametres abstraits, et de l'autre la "diathese homeopathique" construite avec des parametres concrets. L'observation montre que les proteines plasmatiques s'organisent selon quatre etats qui rappellent les quatre diatheses homeopathiques. Ce travail tente de rehabiliter la notion de mode reactionnel individuel