RESUMEN
White-tailed deer (Odocoileus virginianus) are the principal reservoir host for Ehrlichia chaffeensis, causative agent of human monocytic ehrlichiosis (HME). Because white-tailed deer maintain a long-term infection with E. chaffeensis and because deer can be naturally exposed to multiple strains of E. chaffeensis, we evaluated the response to secondary infection of E. chaffeensis in deer. For primary infection, six white-tailed deer were injected with 5.4 x 10(6) DH82 cells infected with the Arkansas strain of E. chaffeensis (Ark) and two control deer were injected with noninfected DH82 cells. On post-infection day 54, three E. chaffeensis (Ark) infected deer and one naive deer were injected with 4.2 x 10(6) cells infected with strain WTD-6045B E. chaffeensis, which differs from the Arkansas strain by number of nucleotide repeats in the variable length PCR target (VLPT) gene; three other Arkansas strain infected deer were injected with noninfected DH82 cells. All animals were monitored for 31 additional days. All deer in the primary infection became positive by PCR amplification of the 16S rRNA or VLPT genes and/or cell culture by DPI-8. PCR amplification of the VLPT gene on whole blood, cell culture, and tissues detected primary and/or secondary strains in all deer exposed to both primary and secondary strains; in one deer, the primary strain was cultured from the lymph node. Our culture results demonstrated that both strains were present; however, PCR detection suggests that the secondary strain may have been circulating in blood at higher levels. In conclusion, this study provides evidence that primary infection of deer with E. chaffeensis does not protect against subsequent exposure and confirms that deer can be simultaneously coinfected with at least two different strains of E. chaffeensis.
Asunto(s)
Ciervos/microbiología , Ehrlichia chaffeensis/genética , Ehrlichia chaffeensis/inmunología , Ehrlichiosis/veterinaria , Animales , Reservorios de Enfermedades/veterinaria , Ehrlichiosis/sangre , Ehrlichiosis/inmunología , Ehrlichiosis/transmisión , Amplificación de Genes , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S , Distribución AleatoriaRESUMEN
Free-ranging mule deer (MD; Odocoileus hemionus) from Arizona and California were tested for evidence of infection with several tick-borne pathogens, including species of Ehrlichia, Anaplasma, Babesia, and Borrelia. Of 125 mule deer tested from Arizona, 29 (23%) and 11 (9%) had antibodies reactive to E. chaffeensis and A. phagocytophilum by indirect immunofluorescent antibody testing, respectively; none of the six MD tested from California were seropositive. Using a commercial competitive ELISA kit, antibodies reactive to Anaplasma spp. were detected in 19 (15%) MD from Arizona and four of six (67%) MD from California. Polymerase chain reaction (PCR) testing for tick-borne pathogens was conducted on blood samples from 29 MD from Arizona and 11 MD from California. Twenty-two of 29 (75.9%) MD from Arizona had PCR evidence of infection with at least one tick-borne pathogen. We detected an Anaplasma sp. in 19 of 29 (65.5%) MD and a Babesia sp. in 10 of 29 (34%) MD. Sequencing of these amplicons indicated that the Anaplasma sp. was the same that had previously been detected in MD from California and the Babesia sp. was similar to one previously detected in a reindeer (Rangifer tarandus tarandus) from California. All of the California MD had evidence of infection with a tick-borne pathogen. Two different species of Anaplasma spp. were detected in MD from California, eight of of 11 MD were infected with an Anaplasma sp., and three of 11 MD were infected with A. ovis. This is the first report of a mule deer naturally infected with A. ovis. Ten of 11 MD from California were infected with a Babesia-like organism previously associated with human disease, and a single MD was PCR positive for Borrelia coriaceae, which has been associated with epizootic bovine abortion. Together, these data suggest that MD in northern Arizona and eastern California are exposed to several pathogens of human and veterinary importance.
Asunto(s)
Ciervos/microbiología , Ciervos/parasitología , Enfermedades por Picaduras de Garrapatas/veterinaria , Zoonosis/epidemiología , Anaplasma phagocytophilum/clasificación , Anaplasma phagocytophilum/genética , Anaplasma phagocytophilum/inmunología , Anaplasma phagocytophilum/aislamiento & purificación , Animales , Anticuerpos Antibacterianos/sangre , Arizona/epidemiología , Babesia/clasificación , Babesiosis/epidemiología , Babesiosis/parasitología , Babesiosis/veterinaria , Borrelia/inmunología , Borrelia/aislamiento & purificación , California/epidemiología , Cartilla de ADN/química , Reservorios de Enfermedades/microbiología , Ehrlichia chaffeensis/clasificación , Ehrlichia chaffeensis/genética , Ehrlichia chaffeensis/inmunología , Ehrlichia chaffeensis/aislamiento & purificación , Ehrlichiosis/microbiología , Ehrlichiosis/transmisión , Ehrlichiosis/veterinaria , Ensayo de Inmunoadsorción Enzimática/métodos , Técnica del Anticuerpo Fluorescente Indirecta/métodos , Humanos , Filogenia , Reacción en Cadena de la Polimerasa/métodos , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADN , Estudios Seroepidemiológicos , Enfermedades por Picaduras de Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/microbiología , Enfermedades por Picaduras de Garrapatas/parasitología , Zoonosis/microbiología , Zoonosis/parasitologíaRESUMEN
Although white-tailed deer (WTD; Odocoileus virginianus ) are considered the primary natural reservoir host for Ehrlichia chaffeensis, the causative agent of human monocytotropic ehrlichiosis, the potential role of other vertebrates as reservoir hosts has not been fully explored. Because domestic goats are naturally infected in areas where E. chaffeensis is endemic in deer, we evaluated the susceptibility of domestic goats to experimental infection with E. chaffeensis. A total of 12 goats were inoculated with E. chaffeensis (15B-WTD-GA or Ark strain)-infected DH82 cells by one of three routes: intravenously, subcutaneously, or intradermally. White-tailed deer simultaneously inoculated with the same dose, route, and inoculum served as positive controls; additional goats and WTD were included as negative controls. Evidence of E. chaffeensis infection was evaluated in all animals by indirect fluorescent antibody assay, PCR, and cell culture isolation techniques. All goats exposed to E. chaffeensis seroconverted by 14 days post-infection (DPI), and E. chaffeensis was isolated from one goat on 3 DPI; however, molecular or cell culture evidence of active infection was not detected in goats later than 3 DPI. White-tailed deer exhibited serologic and molecular evidence of E. chaffeensis infection throughout both trials, and E. chaffeensis was reisolated in cell culture from all infected WTD on numerous days post-infection. Our results suggest that despite the occurrence of natural infection in goats, this animal may not be susceptible to experimental infection and thus may not serve as a suitable model of E. chaffeensis reservoir host infection.
Asunto(s)
Ehrlichia chaffeensis/patogenicidad , Ehrlichiosis/veterinaria , Enfermedades de las Cabras/microbiología , Animales , Ciervos , Reservorios de Enfermedades/veterinaria , Susceptibilidad a Enfermedades/veterinaria , Ehrlichiosis/microbiología , Ehrlichiosis/patología , Femenino , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Enfermedades de las Cabras/patología , Cabras , Inyecciones Intradérmicas/veterinaria , Inyecciones Intravenosas/veterinaria , Inyecciones Subcutáneas/veterinaria , Masculino , Reacción en Cadena de la Polimerasa/veterinaria , Distribución AleatoriaRESUMEN
Southern tick-associated rash illness (STARI) is a Lyme disease-like infection described in patients in the southeastern and south-central United States, where classic Lyme disease is relatively rare. STARI develops following the bite of a lone star tick (Amblyomma americanum) and is thought to be caused by infection with an "uncultivable" spirochete tentatively named Borrelia lonestari. In this study, wild lone star ticks collected from an area where B. lonestari is endemic were cocultured in an established embryonic tick cell line (ISE6). The cultures were examined by dark-field microscopy for evidence of infection, and spirochete identity and morphology were evaluated by flagellin B and 16S rRNA gene sequence, by reaction to Borrelia-wide and B. burgdorferi-specific monoclonal antibodies, and by electron microscopy. Live spirochetes were first visualized in primary culture of A. americanum ticks by dark-field microscopy 14 days after the cell culture was inoculated. The sequences of the flagellin B and 16S rRNA genes of cultured spirochetes were consistent with previously reported sequences of B. lonestari. The cultured spirochetes reacted with a Borrelia-wide flagellin antibody, but did not react with an OspA antibody specific to B. burgdorferi, by indirect fluorescent antibody testing. Electron microscopy demonstrated organisms that were free and associated with ISE6 cells, with characteristic Borrelia sp. morphology. This study describes the first successful isolation of B. lonestari in culture, providing a much needed source of organisms for the development of diagnostic assays and forming a basis for future studies investigating the role of the organism as a human disease agent.
Asunto(s)
Infecciones por Borrelia/diagnóstico , Borrelia/aislamiento & purificación , Infestaciones por Garrapatas/microbiología , Garrapatas/microbiología , Animales , Borrelia/clasificación , Borrelia/citología , Borrelia/genética , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , ADN Ribosómico/genética , ADN Ribosómico/aislamiento & purificación , Flagelina/genética , Técnica del Anticuerpo Fluorescente , Humanos , Microscopía Electrónica de Rastreo , Fenotipo , Filogenia , ARN Bacteriano/genética , ARN Bacteriano/aislamiento & purificación , ARN Ribosómico 16S/genética , ARN Ribosómico 16S/aislamiento & purificación , Serotipificación , Garrapatas/embriologíaRESUMEN
To determine if white-tailed deer may serve as a reservoir host for Borrelia lonestari, we used a nested PCR for the Borrelia flagellin gene to evaluate blood samples collected from deer from eight southeastern states. Seven of 80 deer (8.7%) from 5 of 17 sites (29.4%) had sequence-confirmed evidence of a B. lonestari flagellin gene by PCR, indicating that deer are infected with B. lonestari or another closely related Borrelia species. Our findings expand the known geographic range of B. lonestari and provide the first evidence of this organism in a vertebrate other than humans.
Asunto(s)
Infecciones por Borrelia/veterinaria , Borrelia/aislamiento & purificación , Exantema/etiología , Enfermedades por Picaduras de Garrapatas/veterinaria , Enfermedades de los Animales , Animales , Infecciones por Borrelia/microbiología , Ciervos , Datos de Secuencia Molecular , Enfermedades por Picaduras de Garrapatas/microbiología , Estados UnidosRESUMEN
The infection dynamics of the tick-transmitted organism Ehrlichia chaffeensis were investigated in white-tailed deer (Odocoileus virginianus) using different routes of inoculation. Six deer were each inoculated with 5.4 x 10(6) DH82 cells infected with E. chaffeensis (Arkansas strain) by three different routes: intravenous (n = 2), subcutaneous (n = 2), and intradermal (n = 2). Two control deer were inoculated with uninfected cells. Infections were monitored for 54 days and were continued in one deer from each E. chaffeensis inoculated group for an additional 31 days. All deer inoculated with E. chaffeensis seroconverted (> or = 1: 64) and became 16S rDNA polymerase chain reaction and/or cell culture positive by post-inoculation day 15. There was no apparent (difference in susceptibility to infection between deer inoculated by different routes for the first 50 days based on detection of E. chaffeensis infection by PCR assay of blood or culture isolation. These results demonstrate infection of (deer by intradermal and subcutaneous routes for the first time.
Asunto(s)
Ciervos/microbiología , Ehrlichia chaffeensis/patogenicidad , Ehrlichiosis/veterinaria , Animales , Recuento de Colonia Microbiana/veterinaria , Ehrlichia chaffeensis/aislamiento & purificación , Ehrlichiosis/microbiología , Inyecciones Intradérmicas/veterinaria , Inyecciones Intravenosas/veterinaria , Inyecciones Subcutáneas/veterinaria , Reacción en Cadena de la Polimerasa/veterinaria , ARN Ribosómico 16S/análisis , Distribución AleatoriaRESUMEN
Two closely related zoonotic ehrlichiae, Ehrlichia chaffeensis and E. ewingii, are transmitted by Amblyomma americanum, the lone star tick. Because white-tailed deer (Odocoileus virginianus) are critical hosts for all mobile stages of A. americanum and are important vertebrate reservoirs of E. chaffeensis, we investigated whether deer may be infected with E. ewingii, a cause of granulocytotropic ehrlichiosis in humans and dogs. To test for E. ewingii infection, we used polymerase chain reaction and inoculation of fawns with whole blood from wild deer. Of 110 deer tested from 20 locations in 8 U.S. states, 6 (5.5%) were positive for E. ewingii. In addition, natural E. ewingii infection was confirmed through infection of captive fawns. These findings expand the geographic distribution of E. ewingii, along with risk for human infection, to include areas of Kentucky, Georgia, and South Carolina. These data suggest that white-tailed deer may be an important reservoir for E. ewingii.