Molecular detection of rickettsial tick-borne agents in white-tailed deer (Odocoileus virginianus yucatanensis), mazama deer (Mazama temama), and the ticks they host in Yucatan, Mexico.

Twenty-five white-tailed deer (Odocoileus virginianus yucatanensis) (WTD), 4 mazama deer (Mazama temama) (MD), and the ticks they host in Yucatan, Mexico were sampled to run a molecular survey for tick-borne rickettsial agents. The prevalence of rickettsial agents was 20% in WTD (5/25) and 50% in MD (2/4). When sequencing the nested PCR products, E. chaffeensis, A. phagocytophilum and A. odocoilei, were identified as single infection or coinfecting cervids. None of the cervid samples were positive for E. ewingii, E. canis, nor Rickettsia spp. Overall, 355 individual ticks were collected. Species identified based on adult stages infesting cervids included Amblyomma mixtum, A. parvum, A. cf. oblongoguttatum, Ixodes affinis, Rhipicephalus microplus, R. sanguineus sensu lato, and Haemaphysalis juxtakochi. Rhipicephalus microplus was the tick species most commonly found infesting cervids with a frequency of 28.4%, and intensity of 25.2 ticks per animal. A pool of Amblyomma cf. oblongoguttatum adults and one of Amblyomma spp. nymphs were positive for E. canis and E. chaffeensis, respectively. None of the studied tick pools were positive for E. ewingii, A. phagocytophilum, nor R. rickettsii. To the best of our knowledge, this study is the first to report the prevalence of rickettsial agents in WTD and MD in Mexico. Our molecular study is the first to report the detection of E. chaffeensis, A. phagocytophilum, and A. odocoilei in MD in Mexico. The molecular detection of E. chaffeensis, A. phagocytophilum, and A. odocoilei in deer, and E. chaffeensis in Amblyomma spp. nymphs reported here raises the concern for the risk of human exposure to tick-borne rickettsial pathogens. Our findings highlight the need to apply the "One Health" approach to study ticks and tick-borne diseases. This science-based information could be used by state public-health programs to assess the risk for exposure to tick-borne Anaplasmataceae in Yucatan, Mexico.

Detección de Borrelia burgdorferi sensu lato en perros y sus garrapatas en comunidades rurales de Yucatán, México / Detection of Borrelia burgdorferi sensu lato in dogs and its ticks in rural communities of Yucatán, Mexico

Resumen Actualmente, el estudio de la borreliosis canina adquiere mayor relevancia, ya que el perro es considerado como un importante centinela del complejo Borrelia burgdorferi sensu lato, el cual podría desempeñar un papel clave en la dispersión de garrapatas de las áreas selváticas al ambiente doméstico. En México, la distribución y presencia de genoespecies patógenas de B. burgdorferi en perros y sus garrapatas aún no ha sido investigada. Por tal motivo, la presente investigación tiene como objetivo detectar y estimar la prevalencia de B burgdorferi s.l. en perros y sus garrapatas en dos comunidades rurales de Yucatán, México. En cada comunidad se visitaron 50 viviendas donde se estudiaron 144 muestras de sangre de perros por punción de la vena safena, así como la colecta de sus garrapatas. Se colectaron un total de 846 garrapatas de las especies Ixodes affinis (33 / 846), Rhipicephalus sanguineus sensu lato (786 / 846) y Amblyomma mixtum (27 / 846). Para detectar la presencia de B. burgdorferi s.l. en dichas muestras, se amplificó el gen conservado flaB y las lipoproteínas de membrana externa, ospC y p66, mediante el uso de la reacción en cadena de la polimerasa. La prevalencia obtenida en sangre de perros fue de 17.3 % (25 / 144) para flaB, 12.50 % (18 / 144) para el gen p66 y 1.38 % (2 / 144) para el gen ospC. De las garrapatas analizadas, R. sanguineus s.l. tuvo una prevalencia de infección de 0.89 %, A. mixtum de 5.88 % e I. affinis de 15.15 %, siendo esta última especie la que presentó mayor prevalencia. Dos perros y sus garrapatas I. affinis fueron positivos al gen flaB. Solamente una garrapata R. sanguineus s.l. fue positiva al gen p66 y ninguna especie de garrapata fue positiva al gen ospC. Este estudio confirma la existencia de B. burgdorferi s.l. en perros y sus garrapatas en comunidades rurales de Yucatán, México. La detección de Borrelia en perros podría ser un criterio importante para la evaluación del riesgo de borreliosis en humanos, ya que el perro puede emplearse como indicador epidemiológico para la identificación de nuevos focos de esta enfermedad.

Abstract In Mexico, the distribution and the presence of pathogenic genospecies of B. burgdorferi in dogs and their ticks has not been extensively investigated. The study of canine borreliosis is acquiring greater relevance, since the dog is considered to be an important sentinel for pathogens pertaining to the complex Borrelia burgdorferi sensu lato; in addition, dogs could be playing a key role in the spread of ticks from forested areas into the domestic environment. This study aimed to detect and estimate the prevalence of B. burgdorferi s.l. in dogs and their ticks in two rural communities of Yucatán, Mexico. In each community, 50 houses were visited, where 144 blood samples from dogs were studied by puncture of the saphenous vein, as well as the collection of their ticks. To detect the presence of B. burgdorferi s.l. in these samples, the conserved gene flaB, p66 and ospC were PCR amplified. A total of 144 dog blood samples, and 846 of ticks were obtained from the examined animals. Considering tick species, Rhipicephalus sanguineus sensu lato (786 / 846) was common, while Ixodes affinis (33 / 846), and Amblyomma mixtum (27 / 846) resulted less frequent. As per gene conservation, the prevalence of B. burgdorferi in canine blood was 17.3 % (25 / 144) to flaB, 12.50 % (18 / 144) for p66 and 1.38 % (2 / 144) for the ospC gene. Within the analyzed ticks, R. sanguineus s.l. had a prevalence of 0.89 %, A. mixtum 5.88 % and I. affinis 15.15 %, being this last species the one that presented higher prevalence. Two dogs and their ticks I. affinis were positive to the flaB gene. Only a tick R. sanguineus s.l. was positive to the gene p66 and no tick species was positive the ospC gene. This study confirmed the existence of B. burgdorferi s.l. in dogs and their ticks in rural communities of Yucatán, Mexico. The detection of Borrelia in dogs may be an important criterion for the evaluation of the risk of borreliosis in humans, since the dog can be used as an epidemiological indicator for the identification of new outbreaks of this disease. Rev. Biol. Trop. 66(1): 428-437. Epub 2018 March 01.