Fecha/hora: 11/06/2024 18:15:42

Biblioteca(s): 	INIA Las Brujas.	
Fecha corriente: 	30/06/2021	
Fecha de la última actualización: 	30/06/2021	
Autoria: 	CASTRO JANER, E.; DÍAZ, A.; FONTES, F.; BARAIBAR, F.; SAPORITI, T.; OLHAGARAY, M. E.	
Afiliación: 	ELEONOR CASTRO JANER, Departamento de Patobiología, Unidad de Enfermedades Parasitarias, Facultad de Veterinaria, UDELAR. Montevideo, Uruguay.; ANDRÉ DÍAZ, Departamento de Patobiología, Unidad de Enfermedades Parasitarias, Facultad de Veterinaria, UDELAR. Montevideo, Uruguay.; FLORENCIA FONTES, Departamento de Patobiología, Unidad de Enfermedades Parasitarias, Facultad de Veterinaria, UDELAR. Montevideo, Uruguay.; FLORENCIA BARAIBAR, Departamento de Patobiología, Unidad de Enfermedades Parasitarias, Facultad de Veterinaria, UDELAR. Montevideo, Uruguay.; TATIANA SAPORITI NOGUEIRA, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; MARÍA ERNESTINA OLHAGARAY, Departamento de Patobiología, Unidad de Enfermedades Parasitarias, Facultad de Veterinaria, UDELAR. Montevideo, Uruguay.	
Título: 	Molecular survey of pyrethroid and fipronil resistance in isolates of Rhipicephalus microplus in the north of Uruguay.	
Año de publicación: 	2021	
Fuente/Imprenta: 	Ticks and Tick-borne Diseases, 2021, Volume 12, Issue 5, Article number 101747. Doi: https://doi.org/10.1016/j.ttbdis.2021.101747	
ISSN: 	1877-959X	
DOI: 	10.1016/j.ttbdis.2021.101747	
Idioma: 	Inglés	
Notas: 	Article history: Received 23 July 2020; Received in revised form 29 March 2021; Accepted 6 April 2021; Available online 19 May 2021.
The authors are grateful to the funding of the Instituto Nacional de Investigación Agropecuaria-Plataforma de Salud Animal-Uruguay (CL_35).
Corresponding author: Janer, E.C.; Departamento de Patobiología, Unidad de Enfermedades Parasitarias, Facultad de Veterinaria, UDELAR. Av. Lasplaces 1620, Montevideo, CP, Uruguay; email:elinorcastro59@gmail.com	
Contenido: 	ABSTRACT - The resistance of Rhipicephalus microplus to acaricides is a serious control problem, so its early diagnosis by a molecular technique is important. This study aims to develop a multiplex allele?specific polymerase chain reaction (PCR) for single-nucleotide polymorphisms (SNPs) in the para-sodium channel gene and in the GABA-Cl gene, associated with pyrethroids (cypermethrin and flumethrin) and fipronil resistance, respectively. We used 22 tick field isolates from farms with tick control problems (sampling convenience). These farms are located in departments of northern Uruguay. Three mutations in the sodium channel gene (Domain II S4?5: C190A and G215T; domain III S6: T2134A) and one in the GABA-Cl gene (A286S/L: CG856CC/TG) were studied. Mutations G215T and T213A were not detected. In all field isolates, the resistant allele (R) for C190A mutation (knockdown resistance, kdr) was detected, mainly in heterozygous individuals (SR) (11.1% to 86.7%). The highest incidence of the kdr mutant allele occurred in the Tacuarembó tick field isolates, where on 7 out of 10 farms >30% of individuals were SR and on one farm > 30% of individuals were RR. The next highest was Artigas (half of farms had>30% SR individuals and a quarter had >30% RR individuals). The resistance to dieldrin locus (rdl) mutation (CG856CC/TG) was absent in five field isolates. The highest incidenceof the mutant allele was observed in ticks from farms in Rivera (all farms had SR in >30% of individuals and two farms had RR in >12.5 and >16.7% of individuals) followed by farms in Tacuarembó (3 of 10 farms had >30% SR and 2 with >30% RR). Less than half of the farms had rdl in homozygous individuals. No significant association was observed between phenotypic bioassays and the rdl resistance allele. Several field isolates were phenotypically susceptible to the presence of the rdl allele. Several causes are possible (bioassay sensitivity, discriminating concentration). Individuals with simultaneous kdr and rdl mutations were present in 17 field isolates, and their frequency varied between 0.06% and 60%. Genotypic analysis shows that tick resistance to both acaricides, especially pyrethroids, is a serious problem. It is important to monitor the resistance using molecular techniques to plan efficient control measures. This is the first report describing kdr and rdl detection in R. microplus in Uruguay. © 2021	
Palabras-Clave: 	Acaricides; Ixodidae; Reaxys retrieves substances; Rhipicephalus microplus.	
Categoría del tema: 	L73 Enfermedades de los animales	
Registro original: 	INIA Las Brujas (LB)	
Ejemplares: 	LB - (102722-1) - PXI - AP - DD - PP/Ticks and Tick-borne Diseases/2021 -  -  - DIS