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Rickettsiosis cutáneo ganglionar por Rickettsia conorii en el Uruguay Cutaneous-ganglionar rickettsiosis by Rickettsia conorii in Uruguay  

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Full Text Available Se refieren 3 casos autóctonos de rickettsiosis cutáneo ganglionar trasmitidos por garrapatas de perros (Amblyomma maculatum, en uno de ellos) en el Uruguay. Dos de los 3 casos fueron seguramente provocados por Rickettsia conorii de acuerdo a los resultados de la reacción específica de inmunofluorescencia indirecta - IgM, anti R. conorii. Se incluye un tercer paciente no estudiado con tal técnica, por la similitud clínico-epidemiológica, la reactividad del suero frente al Proteus OX 19 y la rápida respuesta a la tetraciclina. La no descripción previa de la rickettsiosis por R. conorii en forma autóctona en el área de las Américas confiere especial interés a la comunicación, recomendándose la búsqueda de la afección en otros países de la región.Three autochthonous cases of cutaneous-ganglionar rickettsiosis transmitted by dogs ticks (Amblyomma maculatum in one of them) are reported. Two of the three cases were undoubtely produced by Rickettsia conorii according to the results of the specific indirect immunofluorescence technique IEF-IgM anti R. conorii. A third case is included due to the clinical epidemiological similarity, the positive serum reactivity with Proteus O x 19 and the rapid response to tetracycline. Autochthonous rickettsiosis by R. conorii has not been previously registered in the American area what confers special interest to this communication. The search of the disease in the other countries of the region is suggested.

Ismael A. Conti-Diaz; Ivonne Rubio; Raúl E. Somma Moreira; Graciela Pérez Bórmida

1990-01-01

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Clinical and laboratorial evidence of Rickettsia felis infections in Latin America Evidência clínica e laboratorial de infecções por Rickettsia felis na América Latina  

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Full Text Available After the discovery and initial characterization of Rickettsia felis in 1992 by Azad and cols, and the subsequent first description of a human case of infection in 1994, there have been two communications of human rickettsiosis cases caused by Rickettsia felis in Latin America. The first one was published in 2000 by Zavala-Velazquez and cols in Mexico. In 2001 Raoult and cols described the occurrence of two human cases of Rickettsia felis rickettsiosis in Brazil. In the present discussion these two articles were compared and after the description of the principal signs and symptoms, it was concluded that more studies are needed with descriptions of a greater number of patients to establish the true frequency of the clinical signs and symptoms present in Rickettsia felis rickettsiosis.Depois da descoberta e caracterização inicial da Rickettsia felis em 1992 por Azad e cols, e à descrição subseqüente do primeiro caso de infecção humana em 1994, houveram duas comunicações de rickettsioses causadas por Rickettsia felis na América Latina. A primeira foi feita por Zavala-Velazquez e cols em 2000 no México. Em 2001, Raoult e cols descreveram a ocorrência de dois casos humanos de rickettsiose por Rickettsia felis no Brasil. Na presente discussão, esses dois artigos foram comparados, e depois da descrição dos principais sinais e sintomas, conclui-se que outros estudos são necessários, com a participação de um maior número de pacientes, para se estabelecer a verdadeira freqüência dos sinais clínicos e sintomas presentes nas rickettsioses por Rickettsia felis.

Márcio Antônio Moreira Galvão; Cláudio Mafra; Chequer Buffe Chamone; Simone Berger Calic; Jorge E. Zavala-Velazquez; David Hughes Walker

2004-01-01

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Clinical and laboratorial evidence of Rickettsia felis infections in Latin America/ Evidência clínica e laboratorial de infecções por Rickettsia felis na América Latina  

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Full Text Available Abstract in portuguese Depois da descoberta e caracterização inicial da Rickettsia felis em 1992 por Azad e cols, e à descrição subseqüente do primeiro caso de infecção humana em 1994, houveram duas comunicações de rickettsioses causadas por Rickettsia felis na América Latina. A primeira foi feita por Zavala-Velazquez e cols em 2000 no México. Em 2001, Raoult e cols descreveram a ocorrência de dois casos humanos de rickettsiose por Rickettsia felis no Brasil. Na presente discussão (more) , esses dois artigos foram comparados, e depois da descrição dos principais sinais e sintomas, conclui-se que outros estudos são necessários, com a participação de um maior número de pacientes, para se estabelecer a verdadeira freqüência dos sinais clínicos e sintomas presentes nas rickettsioses por Rickettsia felis. Abstract in english After the discovery and initial characterization of Rickettsia felis in 1992 by Azad and cols, and the subsequent first description of a human case of infection in 1994, there have been two communications of human rickettsiosis cases caused by Rickettsia felis in Latin America. The first one was published in 2000 by Zavala-Velazquez and cols in Mexico. In 2001 Raoult and cols described the occurrence of two human cases of Rickettsia felis rickettsiosis in Brazil. In the p (more) resent discussion these two articles were compared and after the description of the principal signs and symptoms, it was concluded that more studies are needed with descriptions of a greater number of patients to establish the true frequency of the clinical signs and symptoms present in Rickettsia felis rickettsiosis.

Galvão, Márcio Antônio Moreira; Mafra, Cláudio; Chamone, Chequer Buffe; Calic, Simone Berger; Zavala-Velazquez, Jorge E.; Walker, David Hughes

2004-06-01

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Rickettsial infection in capybaras (Hydrochoerus hydrochaeris) from São Paulo, Brazil: serological evidence for infection by Rickettsia bellii and Rickettsia parkeri/ Infección por rickettsia en capibaras (Hydrochoerus hydrochaeris) de São Paulo, Brasil: evidencia serológica de infección por Rickettsia bellii y Rickettsia parkeri  

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Full Text Available Abstract in spanish Introducción. En Brasil, los capibaras (Hydrochoerus hydrochaeris) son importantes huéspedes para garrapatas del género Amblyomma, las cuales transmiten rickettsiosis a humanos y animales. Por lo tanto, estos roedores pueden ser potenciales centinelas para detectar infección por rickettsia. Objetivos. Este trabajo evaluó la infección por rickettsia en capibaras de diferentes regiones del estado de São Paulo, donde las rickettsiosis nunca han sido reportadas. Materi (more) ales y métodos. Se examinarion los sueros de 73 capibaras de seis localidades en São Paulo con la prueba de immunofluorescencia indirecta con antígenos de Rickettsia rickettsii, Rickettsia parkeri y Rickettsia bellii. Los bazos de los capibaras se extrajeron y se analizaron por reacción en cadena de la polimerasa para un fragmento del gene gltA de rickettsia. Las garrapatas se recolectaron de los capibaras y se identificaron hasta especie. Resultados. Diecinueve (26,0%), 25 (34,2%) y 50 (68,5%) sueros de los capibaras reaccionaron con R. rickettsii, R. parkeri y R. bellii, respectivamente. De los 50 sueros que reaccionaron con antígenos de R. bellii, 25 presentaron títulos, por lo menos, cuatro veces mayores que los otros dos antígenos. Estos sueros fueron considerados homólogos de R. bellii. Usando el mismo criterio, tres sueros de los capibaras se consideraron homólogos de R. parkeri. Ningún suero se consideró homólogo de R. rickettsii. No se detectó ADN de rickettsia en bazo. Las garrapatas recolectadas de los capibaras fueron identificadas como Amblyomma dubitatum y Amblyomma cajennense. Conclusiones. Este trabajo reporta la primera evidencia de infección natural por R. bellii en vertebrados y, también, la primera evidencia de infección por R. parkeri en capibaras. Se sabe que R. parkeri infecta y produce enfermedad en humanos; sin embargo, no hay evidencia de infección humana por R. bellii. Abstract in english Introduction. In Brazil, capybaras (Hydrochoerus hydrochaeris) are important hosts for Amblyomma ticks, which in turn can transmit rickettsiae to humans and animals. Therefore, capybaras are potential sentinels for rickettsial infection. Objective. The present study evaluated rickettsial infection in capybaras in different areas of the state of São Paulo, where rickettsiosis has never been reported. Materials and methods. Blood sera from 73 capybaras from six localities (more) in São Paulo were tested by indirect immunofluorescence assay using Rickettsia rickettsii, Rickettsia parkeri, and Rickettsia bellii antigens. Capybara spleens were tested by PCR, targeting a fragment of the rickettsial gltA gene. Ticks were collected from each capybara sample and taxonomically identified to species. Results. A total of 94 positively reacting capybara samples, 19 (26.0%), 25 (34.2%), and 50 (68.5%) capybara sera reacted to R. rickettsii, R. parkeri, and R. bellii, respectively. Twenty-five capybara sera showed titers to R. bellii at least four-fold higher than to any of the other two antigens. These sera were considered homologous to R. bellii. Using the same criteria, 3 capybara sera were considered homologous to R. parkeri. No sera were be considered homologous to R. rickettsii. No rickettsial DNA was detected in capybara spleen samples. Ticks collected on capybaras were Amblyomma dubitatum and Amblyomma cajennense. Conclusions. The first evidence is reported of R. bellii natural infection in vertebrate hosts, and the first evidence of R. parkeri infection in capybaras. While R. parkeri is known to infect and cause disease in humans, no similar evidence for human infection has been indicated by R. bellii.

Pacheco, Richard C; Horta, Mauricio C; Moraes-Filho, Jonas; Ataliba, Alexandre C; Pinter, Adriano; Labruna, Marcelo B

2007-09-01

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TUBERCULOSIS GANGLIONAR RETROPERITONEAL Y MESENTERICA: CASO CLINICO  

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Full Text Available Abstract in spanish Se describen las características del compromiso ganglionar por Mycobacterium tuberculosis en un paciente con SIDA en quien se demuestra alteraciones de linfonódulos retroperitoneales y mesentéricos en tomografía computada. Se discute las diferencias con el compromiso secundario a infección por Mycobacterium avium intracellulare y además el diagnóstico diferencial con otras formas de compromiso ganglionar Abstract in english The changes of retroperitoneal lymph nodes in CT in a patient with AIDS are described. Differences with the compromise with M avium-intracellulare are discussed an also the differential diagnosis with other lymph node pathologies

Martínez F, Rafael; Reyes O, Paula; Schiappacasse F, Giancarlo; Cruz O, Francisco; Solar G, Antonieta

2004-01-01

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TUBERCULOSIS GANGLIONAR RETROPERITONEAL Y MESENTERICA: CASO CLINICO  

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Full Text Available Se describen las características del compromiso ganglionar por Mycobacterium tuberculosis en un paciente con SIDA en quien se demuestra alteraciones de linfonódulos retroperitoneales y mesentéricos en tomografía computada. Se discute las diferencias con el compromiso secundario a infección por Mycobacterium avium intracellulare y además el diagnóstico diferencial con otras formas de compromiso ganglionarThe changes of retroperitoneal lymph nodes in CT in a patient with AIDS are described. Differences with the compromise with M avium-intracellulare are discussed an also the differential diagnosis with other lymph node pathologies

Rafael Martínez F; Paula Reyes O; Giancarlo Schiappacasse F; Francisco Cruz O; Antonieta Solar G

2004-01-01

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Serological evidence of Rickettsia parkeri as the etiological agent of rickettsiosis in Uruguay/ Evidência sorológica de Rickettsia parkeri como agente etiológico de rickettsiose no Uruguai  

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Full Text Available Abstract in portuguese São relatados três novos casos humanos de rickettsiose no Uruguai. Os três casos clínicos apresentam manifestações clínicas semelhantes às descritas em casos de infecção por Rickettsia parkeri previamente relatados nos Estados Unidos, tais como: febre moderada ((more) m antígenos de R. parkeri e Rickettsia rickettsii, associados à reação de imunofluorescência indireta, sugerem que os pacientes de dois casos foram infectados por R. parkeri. Evidências clínicas e epidemiológicas, associadas com nossas análises sorológicas, sugerem que R. parkeri é o agente etiológico de casos humanos de febre maculosa no Uruguai, uma doença que tem sido reconhecida naquele país como rickettsiose cutâneo-ganglionar. Abstract in english We report three new rickettsiosis human cases in Uruguay. The three clinical cases presented clinical manifestations similar to previous reported cases of Rickettsia parkeri in the United States; that is mild fever ((more) ssay indicated that the patients in two cases were infected by R. parkeri. Epidemiological and clinical evidences, coupled with our serological analysis, suggest that R. parkeri is the etiological agent of human cases of spotted fever in Uruguay, a disease that has been recognized in that country as cutaneous-ganglionar rickettsiosis.

Conti-Díaz, Ismael A.; Moraes-Filho, Jonas; Pacheco, Richard C.; Labruna, Marcelo B.

2009-12-01

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Vigilancia de la infección por Rickettsia sp. en capibaras (Hydrochoerus hydrochaeris) un modelo potencial de alerta epidemiológica en zonas endémicas/ Surveillance of Rickettsia sp. infection in capybaras (Hydrochoerus hydrochaeris) a potential model of epidemiological alert in endemic areas  

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Full Text Available Abstract in spanish Introducción. Los capibaras o chigüiros (Hydrochoerus hydrochaeris) son huéspedes amplificadores de Rickettsia sp. Usualmente se encuentran parasitados por la garrapata Amblyomma cajennense, principal vector de rickettsiosis en Suramérica. Los capibaras pueden ser usados como potenciales centinelas de la circulación de rickettsias. Objetivo. Detectar anticuerpos contra Rickettsia sp. del grupo de las fiebres manchadas en capibaras de una zona rural del municipio de M (more) ontería, departamento de Córdoba. Material y métodos. Se analizaron 36 sueros de capibaras de una zona rural de Montería (vereda San Jerónimo) en Córdoba. Para la detección de anticuerpos IgG se practicó inmunofluorescencia indirecta, que utilizó antígenos de la cepa Taiaçu de Rickettsia rickettsii de Brasil. Los sueros de los capibaras fueron diluidos 1:64. Se capturaron las garrapatas que se encontraban parasitando los capibaras y se clasificaron hasta su especie. Resultados. La seroprevalencia contra Rickettsia sp. del grupo de la fiebres manchadas encontrada fue de 22 % (8 capibaras); se encontraron cuatro sueros con título de 1:64, tres sueros con título 1:128 y un suero presentó titulación de 1:512. Todas las garrapatas (n=933) fueron identificadas taxonómicamente como A. cajennense. Conclusión. En Colombia existen zonas endémicas de rickettsiosis y la aparición de brotes anuales lo confirma (Necoclí, 2006; Los Córdobas, 2007, y Altos de Mulatos, 2008). El presente estudio reporta por primera vez la presencia de infección natural por rickettsia del grupo de las fiebres manchadas en capibaras de Colombia. Los hallazgos sugieren que los capibaras pueden ser usados como potenciales centinelas de la circulación de rickettsias y marcadores de las áreas de riesgo para la transmisión de rickettsiosis. Abstract in english Introduction. Capybaras (Hydrochoerus hydrochaeris) are considered amplifying hosts of Rickettsia sp. These rodents are usually parasitized by the tick vector, Amblyomma cajennense, the main vector of rickettsioses in humans and animals in South America. Capybaras can be used as sentinels in detection of circulation of rickettsiae. Objective. Antibodies to rickettsiae of spotted fever group were detected in capybaras in a rural area of Cordoba Province, northern Colombia. (more) Materials and methods. Sera were analyzed from 36 capybaras in a rural area of Monteria (village of San Jeronimo) in Córdoba. For the detection of IgG antibodies, indirect immunofluorescence was performed. The antigens were derived from R. rickettsia strain Taiaçu isolated in Brazil. Capybara sera were diluted 1:64 for IFA analysis. Ticks were collected from each capybara (also known as chigüiro) and identified to species. Results. The seroprevalence of spotted fever group Rickettsia was 22% (8 capybaras). Four sera had a titer of 1:64, 3 had a titer of 1:128 and one serum had a titer of 1:512. All ticks removed from the capybaras (n=933) were taxonomically identified as Amblyomma cajennense. Conclusion. Colombia has areas endemic for rickettsioses, as indicated by confirmed annual outbreaks. The current study reports the first evidence of natural rickettsial infection of the spotted fever group in capybaras from Colombia. The findings suggest that capybaras can be used as sentinels for the circulation of rickettsiae and can identify endemic areas for the transmission of rickettsial diseases.

Miranda, Jorge; Contreras, Verónica; Negrete, Yésica; Labruna, Marcelo B; Máttar, Salim

2011-06-01

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Rickettsia parkeri: a Rickettsial pathogen transmitted by ticks in endemic areas for spotted fever rickettsiosis in southern Uruguay/ Rickettsia parkeri: patógeno rickettsial transmitido por garrapatas en áreas endémicas de rickettsiosis por fiebre manchada en el sur de Uruguay  

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Full Text Available Abstract in spanish Inicialmente, Rickettsia conorii fue señalada como el agente causal de la fiebre manchada en Uruguay, diagnosticada mediante pruebas serológicas. Posteriormente, Rickettsia parkeri fue detectada mediante técnicas moleculares en garrapatas Amblyomma triste colectadas sobre humanos. El vector natural de R. conorii, Rhipicephalus sanguineus, no ha sido estudiado en cuanto a rickettsias en Uruguay. Para abordar este tema, 180 R. sanguineus fueron colectados sobre perros y (more) 245 A. triste sobre vegetación en tres localidades consideradas endémicas para fiebres manchadas en el sur de Uruguay. El ADN de las garrapatas fue extraído en pools y sometido a una primera PCR utilizando cebadores que amplifican un fragmento del gen gltA, presente en prácticamente todas las especies de Rickettsia. Las muestras positivas fueron sometidas a una segunda PCR con cebadores que amplifican un fragmento del gen ompA, presente sólo en rickettsias del grupo de las fiebres manchadas (GFM). No se detectó ADN rickettsial en R. sanguineus. Sin embargo, muestras de A. triste fueron positivas a rickettsiales en dos de las tres localidades estudiadas, con prevalencias de pools positivos del 11.8 y 37.5% respectivamente. La secuenciación del ADN evidenció la presencia de R. parkeri. Basados en estos resultados junto a los anteriores y la agresividad de A. triste hacia los humanos, se concluye que esta garrapata es vector de rickettsiosis humana por R. parkeri en Uruguay. Abstract in english At first Rickettsia conorii was implicated as the causative agent of spotted fever in Uruguay diagnosed by serological assays. Later Rickettsia parkeri was detected in human-biting Amblyomma triste ticks using molecular tests. The natural vector of R. conorii, Rhipicephalus sanguineus, has not been studied for the presence of rickettsial organisms in Uruguay. To address this question, 180 R. sanguineus from dogs and 245 A. triste from vegetation (flagging) collected in th (more) ree endemic localities were screened for spotted fever group (SFG) rickettsiosis in southern Uruguay. Tick extracted DNA pools were subjected to PCR using primers which amplify a fragment of the rickettsial gltA gene. Positive tick DNA pools with these primers were subjected to a second PCR round with primers targeting a fragment of the ompA gene, which is only present in SFG rickettsiae. No rickettsial DNA was detected in R. sanguineus. However, DNA pools of A. triste were found to be positive for a rickettsial organism in two of the three localities, with prevalences of 11.8% to 37.5% positive pools. DNA sequences generated from these PCR-positive ticks corresponded to R. parkeri. These findings, joint with the aggressiveness shown by A. triste towards humans, support previous data on the involvement of A. triste as vector of human infections caused by R. parkeri in Uruguay.

Venzal, José M.; Estrada-Peña, Agustín; Portillo, Aránzazu; Mangold, Atilio J.; Castro, Oscar; Souza, Carlos G. De; Félix, María L.; Pérez-Martínez, Laura; Santibánez, Sonia; Oteo, José A.

2012-06-01

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Fiebre manchada por rickettsias en el Delta del Paraná: Una enfermedad emergente Rickettsial spotted fever in the Paraná Delta: An emerging disease  

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Full Text Available Se comunica un caso de fiebre manchada por rickettsia autóctono del delta del Paraná correspondiente a la provincia de Buenos Aires. Luego de cinco días de haber permanecido en una región cercana a la localidad de ingeniero Otamendi, partido de Campana, el paciente presentó un síndrome febril agudo caracterizado por hipertermia con escalofríos y sudoración, mialgias, cefalea, astenia y discreta odinofagia, seguido a las 72 horas por un exantema maculopapuloso congestivo con elementos purpúricos, de distribución universal. En la región preauricular izquierda se observaba una lesión papuloerosiva, producida cinco días antes de iniciada la fiebre por una garrapata adquirida en el lugar. El cuadro clínico remitió rápidamente con la administración de doxiciclina. Por inmunofluorescencia indirecta se identificaron anticuerpos reactivos contra el grupo de rickettsias causantes de fiebres manchadas (CDC, Atlanta, EE.UU.). Se realizan consideraciones sobre la especie de rickettsia, el vector involucrado y la posibilidad que la enfermedad fuera debida a Rickettsia parkeri.We describe a case of rickettsial spotted fever in the Paraná Delta region of Buenos Aires province in Argentina. The patient developed an acute febrile syndrome characterized by myalgias, headache, asthenia and moderate odynophagia, followed by a diffuse macular, papular, and purpuric exanthema. The patient had been bitten recently by a tick on the left preauricular region and an erosive papular lesion was evident at the bite site. An indirect immunofluorescence antibody assay identified antibodies reactive with spotted fever group rickettsiae in the patient's serum. The patient improved rapidly with doxycycline. Several considerations relating to the identity of the rickettsial species and tick vector are discussed, including the possibility that this patient's illness may have been caused by Rickettsia parkeri.

Alfredo Seijo; Marisa Picollo; William Nicholson; Christopher Paddock

2007-01-01

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Fiebre manchada por rickettsias en el Delta del Paraná: Una enfermedad emergente/ Rickettsial spotted fever in the Paraná Delta: An emerging disease  

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Full Text Available Abstract in spanish Se comunica un caso de fiebre manchada por rickettsia autóctono del delta del Paraná correspondiente a la provincia de Buenos Aires. Luego de cinco días de haber permanecido en una región cercana a la localidad de ingeniero Otamendi, partido de Campana, el paciente presentó un síndrome febril agudo caracterizado por hipertermia con escalofríos y sudoración, mialgias, cefalea, astenia y discreta odinofagia, seguido a las 72 horas por un exantema maculopapuloso cong (more) estivo con elementos purpúricos, de distribución universal. En la región preauricular izquierda se observaba una lesión papuloerosiva, producida cinco días antes de iniciada la fiebre por una garrapata adquirida en el lugar. El cuadro clínico remitió rápidamente con la administración de doxiciclina. Por inmunofluorescencia indirecta se identificaron anticuerpos reactivos contra el grupo de rickettsias causantes de fiebres manchadas (CDC, Atlanta, EE.UU.). Se realizan consideraciones sobre la especie de rickettsia, el vector involucrado y la posibilidad que la enfermedad fuera debida a Rickettsia parkeri. Abstract in english We describe a case of rickettsial spotted fever in the Paraná Delta region of Buenos Aires province in Argentina. The patient developed an acute febrile syndrome characterized by myalgias, headache, asthenia and moderate odynophagia, followed by a diffuse macular, papular, and purpuric exanthema. The patient had been bitten recently by a tick on the left preauricular region and an erosive papular lesion was evident at the bite site. An indirect immunofluorescence antibod (more) y assay identified antibodies reactive with spotted fever group rickettsiae in the patient's serum. The patient improved rapidly with doxycycline. Several considerations relating to the identity of the rickettsial species and tick vector are discussed, including the possibility that this patient's illness may have been caused by Rickettsia parkeri.

Seijo, Alfredo; Picollo, Marisa; Nicholson, William; Paddock, Christopher

2007-12-01

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Serological evidence of Rickettsia parkeri as the etiological agent of rickettsiosis in Uruguay Evidência sorológica de Rickettsia parkeri como agente etiológico de rickettsiose no Uruguai  

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Full Text Available We report three new rickettsiosis human cases in Uruguay. The three clinical cases presented clinical manifestations similar to previous reported cases of Rickettsia parkeri in the United States; that is mild fever (São relatados três novos casos humanos de rickettsiose no Uruguai. Os três casos clínicos apresentam manifestações clínicas semelhantes às descritas em casos de infecção por Rickettsia parkeri previamente relatados nos Estados Unidos, tais como: febre moderada (< 40 ºC), mal-estar, cefaléia, exantema, escara de inoculação no sítio de fixação do carrapato, linfadenopatia regional e ausência de letalidade. Testes sorológicos de absorção de anticorpos com antígenos de R. parkeri e Rickettsia rickettsii, associados à reação de imunofluorescência indireta, sugerem que os pacientes de dois casos foram infectados por R. parkeri. Evidências clínicas e epidemiológicas, associadas com nossas análises sorológicas, sugerem que R. parkeri é o agente etiológico de casos humanos de febre maculosa no Uruguai, uma doença que tem sido reconhecida naquele país como rickettsiose cutâneo-ganglionar.

Ismael A. Conti-Díaz; Jonas Moraes-Filho; Richard C. Pacheco; Marcelo B. Labruna

2009-01-01

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Fatal Brazilian spotless fever caused by Rickettsia rickettsii in a dark-skinned patient/ Febre maculosa brasileira sem exantema causada por Rickettsia rickettsii em um paciente de cor negra  

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Full Text Available Abstract in portuguese Febre maculosa brasileira (FMB) é a mais importante e frequente doença rickettsial no Brasil. Relatamos um caso fatal de FMB em um homem negro de 32 anos de idade que morreu de choque irreversível após cinco dias de febre, cefaléia intensa, dor abdominal, e sem evidência de exantema. Amostras de baço, rim e coração coletadas na necropsia foram positivas para Rickettsia rickettsii por PCR e sequenciamento. Os autores ressaltam a necessidade de um alto índice de s (more) uspeita diagnóstica para febre maculosa em pacientes negros. Ausência de exantema não deve dissuadir os clínicos de considerar a possibilidade de FMB e iniciar a terapêutica empírica. Abstract in english Brazilian spotted fever (BSF) is the most important and frequent rickettsial disease in Brazil. A fatal case of BSF is reported in a 32-year-old black man, who died of irreversible shock after five days of fever, severe headache and abdominal pain with no rash. Spleen, kidney and heart samples collected at autopsy were positive for Rickettsia rickettsii by PCR and sequencing. The authors emphasize the need for a high index of diagnostic suspicion for spotted fever in blac (more) k patients. Absence of a skin rash should not dissuade clinicians from considering the possibility of BSF and initiating empirical therapy.

Favacho, Alexsandra Rodrigues de Mendonça; Rozental, Tatiana; Calic, Simone Berger; Scofield, Maria Aparecida Mota; Lemos, Elba Regina Sampaio de

2011-06-01

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Fatal Brazilian spotless fever caused by Rickettsia rickettsii in a dark-skinned patient Febre maculosa brasileira sem exantema causada por Rickettsia rickettsii em um paciente de cor negra  

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Full Text Available Brazilian spotted fever (BSF) is the most important and frequent rickettsial disease in Brazil. A fatal case of BSF is reported in a 32-year-old black man, who died of irreversible shock after five days of fever, severe headache and abdominal pain with no rash. Spleen, kidney and heart samples collected at autopsy were positive for Rickettsia rickettsii by PCR and sequencing. The authors emphasize the need for a high index of diagnostic suspicion for spotted fever in black patients. Absence of a skin rash should not dissuade clinicians from considering the possibility of BSF and initiating empirical therapy.Febre maculosa brasileira (FMB) é a mais importante e frequente doença rickettsial no Brasil. Relatamos um caso fatal de FMB em um homem negro de 32 anos de idade que morreu de choque irreversível após cinco dias de febre, cefaléia intensa, dor abdominal, e sem evidência de exantema. Amostras de baço, rim e coração coletadas na necropsia foram positivas para Rickettsia rickettsii por PCR e sequenciamento. Os autores ressaltam a necessidade de um alto índice de suspeita diagnóstica para febre maculosa em pacientes negros. Ausência de exantema não deve dissuadir os clínicos de considerar a possibilidade de FMB e iniciar a terapêutica empírica.

Alexsandra Rodrigues de Mendonça Favacho; Tatiana Rozental; Simone Berger Calic; Maria Aparecida Mota Scofield; Elba Regina Sampaio de Lemos

2011-01-01

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AFECTACIÓN GANGLIONAR EN PACIENTE CON ENDOMETRIOSIS PROFUNDA RECTOVAGINAL  

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Full Text Available Abstract in spanish Se describe un raro caso de endometriosis rectovaginal con compromiso ganglionar en mujer de 33 años. La presencia de tejido endometrial en ganglios linfáticos pélvicos es rara y ha sido confirmada en la literatura en mujeres que han sido sometidas a cirugía por endometriosis. La presencia de endometriosis en los ganglios linfáticos pélvicos es muy improbable que surja de novo y sugiere extensión de la enfermedad. Abstract in english A rare case of rectovaginal endometriosis with lymph node involvement is described in a 33-year-old patient. The presence of endometrial tissue in pelvic lymph nodes is rare and has been confirmed in the literature in subjects who underwent surgery for endometriosis. Involvement of pelvic lymph nodes by endometriosis seems unlikely to arise de novo and probably suggests lymphatic spread of the disease.

Ortega Sánchez, Israel; Castro Martín, Bárbara; de Santiago García, Javier; Hernández Gutiérrez, Alicia; Benito López, Dulce Mª; Ordás Santo Tomás, Juan

2009-01-01

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AFECTACIÓN GANGLIONAR EN PACIENTE CON ENDOMETRIOSIS PROFUNDA RECTOVAGINAL  

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Full Text Available Se describe un raro caso de endometriosis rectovaginal con compromiso ganglionar en mujer de 33 años. La presencia de tejido endometrial en ganglios linfáticos pélvicos es rara y ha sido confirmada en la literatura en mujeres que han sido sometidas a cirugía por endometriosis. La presencia de endometriosis en los ganglios linfáticos pélvicos es muy improbable que surja de novo y sugiere extensión de la enfermedad.A rare case of rectovaginal endometriosis with lymph node involvement is described in a 33-year-old patient. The presence of endometrial tissue in pelvic lymph nodes is rare and has been confirmed in the literature in subjects who underwent surgery for endometriosis. Involvement of pelvic lymph nodes by endometriosis seems unlikely to arise de novo and probably suggests lymphatic spread of the disease.

Israel Ortega Sánchez; Bárbara Castro Martín; Javier de Santiago García; Alicia Hernández Gutiérrez; Dulce Mª Benito López; Juan Ordás Santo Tomás

2009-01-01

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First identification of natural infection of Rickettsia rickettsii in the Rhipicephalus sanguineus tick, in the State of Rio de Janeiro Primeira identificação de infecção natural por Rickettsia rickettsii no carrapato Rhipicephalus sanguineus no Rio de Janeiro  

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Full Text Available The Brazilian Spotted Fever (BSF) is a zoonotic disease caused by Rickettsia rickettsii and transmitted by ticks of the genus Amblyomma, more frequently, Amblyomma cajennense. The aim of this paper was to report the first molecular detection of R. rickettsii on R. sanguineus naturally infected in Rio de Janeiro, Brazil. Ticks were collected from dogs in a rural region of Resende municipality, Rio de Janeiro State, Brazil (22º30'9.46"S, 44º42'44.29"WO), where occurred five human cases of BSF in 2006. The ticks were identified under a stereoscopic microscope and separated in pools by stages, species and sex. DNA extraction was carried out using QIAamp DNA Mini Kit (QIAGEN®). The DNA was submitted to PCR amplification using 04 set of primers: Rr190.70p/Rr190.602n (OmpA, 532bp), BG1-21/BG2-20 (OmpB, 650bp), Tz15/Tz16 (17 kDa protein-encoding gene, 246bp) and RpCS.877p/RpCS.1258n (gltA, 381bp). PCR products were separated by electrophoresis on 1% agarose gels and visualized under ultraviolet light with ethidium bromide. PCR products of the expected sizes were purified by QIAquick® and sequenced by ABI PRISM®. The generated nucleotide sequences were edited with using Bioedit® software and compared with the corresponding homologous sequences available through GenBank, using Discontiguous Mega Blast (http://www.ncbi.nlm.nih.gov). It was confirmed R. rickettsii by sequencing of the material (GenBank FJ356230). The molecular characterization of R. rickettsii in the tick R. sanguineus emphasizes the role of dogs as carriers of ticks from the environment to home. Moreover, this result suggests that there is a considerable chance for active participation of R. sanguineus as one of tick species in the transmission of R. ricketsii to human being in the Brazilian territory.A Febre Maculosa Brasileira (FMB) é uma zoonose causada por Rickettsia rickettsii e transmitida por carrapatos do gênero Amblyomma, mais freqüentemente pela espécie Amblyomma cajennense. Este trabalho tem como objetivo relatar a primeira detecção molecular de R. rickettsii em Rhipicephalus sanguineus naturalmente infectado no Rio de Janeiro, Brasil. Carrapatos foram coletados de cães, procedentes de uma região rural do município de Resende, estado do Rio de Janeiro, Brasil (22º30'9.46"S, 44º42'44.29"WO), onde ocorreram cinco casos humanos de FMB em 2006. Todos os carrapatos foram identificados segundo chave dicotômica, utilizando-se lupa estereoscópica e separados de acordo com estágio, espécie e sexo. Para a extração de DNA utilizou-se o kit comercial QIAamp DNA (QIAGEN ®). O DNA foi submetido à técnica de PCR utilizando 04 conjuntos de iniciadores para a amplificação dos genes: Rr190.70p/Rr190.602n (OmpA, 532bp), BG1-21/BG2-20 (OmpB, 650bp), Tz15/Tz16 (17 kDa gene que codifica a proteína, 246bp) e RPCs .877p/RpCS.1258n (gltA, 381bp). Os produtos da PCR foram separados por eletroforese em gel agarose 1% corados com brometo de etídio e visualizados sob luz ultravioleta e, aqueles que apresentaram bandas amplificadas foram purificados utilizando-se o kit comercial QIAquick ® e seqüenciados pelo ABI PRISM®. As seqüências nucleotídicas foram geradas usando Bioedit®, editado em software e comparados os correspondentes homólogos com as sequências disponíveis através GenBank, utilizando Discontiguous Mega Blast (http://www.ncbi.nlm.nih.gov). Confirmou-se R. rickettsii (GenBank FJ356230) no seqüenciamento de apenas um espécime, adulto de carrapato R. sanguineus. A caracterização molecular de R. rickettsii em exemplar de carrapato R. sanguineus confirma que esta espécie pode ter importante papel na transmissão de R. rickettsii para humanos no território brasileiro.

Nathalie C. Cunha; Adivaldo H. Fonseca; Jania Rezende; Tatiana Rozental; Alexsandra R.M. Favacho; Jairo D. Barreira; Carlos L. Massard; Elba R.S. Lemos

2009-01-01

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Epidemiología de rickettsiosis por Rickettsia parkeri y otras especies emergentes o re-emergentes asociadas a la antropización en Latinoamérica/ Epidemiology of rickettsioses by Rickettsia parkeri andother emerging and reemerging species associated with anthropization in Latin America  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Se describe la importancia regional de Rickettsia parkeri y sus respectivos vectores. Se hace énfasis en los factores de antropización que favorecen la aparición de hospedadores alternativos para las garrapatas en los entornos domésticos y peridomésticos, generando modificaciones en la epidemiología del agente etiológico. También se menciona las modificaciones ecológicas que pueden favorecen el incremento de poblaciones de reservorios para las garrapatas incrementando el riesgo para el ser humano de sufrir enfermedades rickettsiales. Abstract in english A description of the regional importance of Rickettsia parkeri and their vectors is presented. There is emphasis on the factors of anthropization that favor the development of alternative hosts for ticks in domestic and peridomestic environments, generating changes in the epidemiology of the etiological agent. The environmental changes that can promote the increase in populations of tick reservoirs, increasing the risk for humans for rickettsial diseases, is also mentioned.

Venzal, José M

2013-07-01

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Environmental infestation and rickettsial infection in ticks in an area endemic for Brazilian spotted fever/ Infestacao ambiental e infeccao por rickettsias em carrapatos de area endemica para Febre Maculosa Brasileira  

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Full Text Available Abstract in portuguese A Febre Maculosa Brasileira (FMB) é uma antropozoonose endêmica no município de Americana/SP, causada pela bactéria Rickettsia rickettsii e transmitida pelo carrapato Amblyomma cajennense. Este estudo avaliou a fauna de carrapatos e a infecção por riquétsias em carrapatos de vida livre capturados mensalmente com armadilhas de CO2, em áreas de risco para FMB de Americana, de julho de 2009 a junho de 2010. Duas espécies foram cap (more) turadas, A. cajennense (6.122 larvas; 4.265 ninfas; 2.355 adultos) e Amblyomma dubitatum (7.814 larvas; 3.364 ninfas; 1.193 adultos). Os estágios imaturos de A. cajennense e A. dubitatum apresentaram uma distribuição anual semelhante, com larvas de ambas as espécies sendo coletadas em maior número no período de abril a julho e ninfas de junho a outubro. Maior número de adultos de A. cajennense foi coletado de outubro a dezembro, enquanto que os adultos de A. dubitatum foram coletados em número relativamente semelhante durante todo o ano. A infecção por Rickettsia foi avaliada pela PCR em 1157 carrapatos A. cajennense e 1040 A. dubitatum, com apenas 41 (3,9%) A. dubitatum infectados com Rickettsia bellii. Este estudo demonstrou que as áreas de risco para FMB de Americana são caracterizadas por elevadas infestações ambientais de A. cajennense e A. dubitatum. Abstract in english Brazilian spotted fever (BSF), caused by Rickettsia rickettsii, is endemic in the municipality of Americana, southeastern Brazil, where the disease is transmitted by the tick Amblyomma cajennense. This study evaluated the tick fauna and rickettsial infection in free-living ticks that were captured monthly using dry ice traps in areas endemic for BSF in Americana, from July 2009 to June 2010. Two tick species were captured: A. cajennense (6,122 larvae; 4,265 nymphs; 2,355 (more) adults) and Amblyomma dubitatum (7,814 larvae; 3,364 nymphs; 1,193 adults). The immature stages of A. cajennense and A. dubitatum had similar distribution through the 12-month period, with larvae of both species collected in highest numbers between April and July, and nymphs between June and October. The highest numbers of A. cajennense adults were collected between October and December, whereas A. dubitatum adults were collected in relatively similar numbers throughout the 12-month period. Rickettsial infection was evaluated by means of PCR in 1,157 A. cajennense and 1,040 A. dubitatum ticks; only 41 (3.9%) A. dubitatum were found to be infected by Rickettsia bellii. The present study showed that the areas of Americana that are endemic for BSF are characterized by high environmental burdens of A. cajennense and A. dubitatum.

Brites-Neto, Jose; Nieri-Bastos, Fernanda Aparecida; Brasil, Jardel; Duarte, Keila Maria Roncato; Martins, Thiago Fernandes; Verissimo, Cecilia Jose; Barbieri, Amalia Regina Mar; Labruna, Marcelo Bahia

2013-09-01

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Factores predictores de metástasis ganglionar en el carcinoma diferenciado de tiroides  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Antecedentes: son necesarios factores pronósticos confiables de metástasis ganglionar para adaptar el tratamiento quirúrgico inicial de pacientes con carcinoma diferenciado de tiroides. Objetivo: determinar la frecuencia y factores pronósticos asociados con metástasis ganglionar en pacientes operados por carcinoma diferenciado de tiroides. Lugar de apicación: práctica privada. Diseño: retrospectivo observacional. Pobación: entre enero de 2000 y agosto de 2010, a (more) 600 pacientes con 639 tumores (39 bilaterales) se les realizó tiroidectomía total y linfadenectomía terapéutica sólo cuando se demostró metástasis por biopsia ganglionar. Método: revisión de historias clínicas e informes patológicos. Resutados: 145 enfermos (22.7 %) tuvieron ganglios histológicamente positivos. El análisis multivariado mostró que la edad menor de 45 años (p = 0.001), adenopatías palpables (p = 0.0001), multicentricidad (p = 0.005) e invasión extracapsular (p = 0.0001) fueron factores de riesgo independientes de metástasis ganglionar. Estos factores, en conjunto, tuvieron una alta especificidad (97 %)y una baja sensibilidad (40 %). Se encontraron metástasis en ganglios yugulares con ganglios centrales negativos ("skip" metástasis) en 29 casos (5.54 %). Concusiones: a pesar de que algunos de los factores estudiados tuvieron valor pronóstico, se requieren variables adicionales para definir mejor el manejo quirúrgico. Abstract in english Background: reliable prognostic factors of lymph node metástasis are needed to adapt initial surgical treatment of patients with differentiated thyroid carcinoma. Objetive: to determine the frequency and predictive factors associated with lymph node metástasis in patients operated on for differentiated thyroid carcinoma. Setting: prívate practice. Design: retrospective observational. Popuation: between January 2000 and August 2010, 600 patients with 639 tumours (39 bil (more) ateral) underwent total thyroidectomy and therapeutic neck dissection only when there was biopsy proved lymph node metástasis. Method: review of clinical records and pathological reports. Resuts: 145 patients (22.7 %) had histologically positive lymph nodes. Multivariate analysis showed that lessthan 45 years (p = 0.001), palpable adenopathy (p = 0.0001), multicentricity (p = 0.005) and extracapsular invasión (p = 0.0001) were independent risk factors of lymph node metástasis. These factors, together, had high specificity (97 %) but low sensibility (40 %). Metástasis in jugular lymph nodes with normal central nodes (skip metástasis) was found in 29 (5.54 %) cases. Concusions: even though some of the factors studied proved to be of prognostic valué, additional variables are needed to better define surgical management.

Falco, Jorge E; Otero Muñoz, Alvaro; Montesinos, Manuel R

2012-12-01

 
 
 
 
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Tropism and pathogenicity of rickettsiae.  

UK PubMed Central (United Kingdom)

Rickettsiae are obligate intracellular parasitic bacteria that cause febrile exanthematous illnesses such as Rocky Mountain spotted fever, Mediterranean spotted fever, epidemic, and murine typhus, etc. Although the vector ranges of each Rickettsia species are rather restricted; i.e., ticks belonging to Arachnida and lice and fleas belonging to Insecta usually act as vectors for spotted fever group (SFG) and typhus group (TG) rickettsiae, respectively, it would be interesting to elucidate the mechanisms controlling the vector tropism of rickettsiae. This review discusses the factors determining the vector tropism of rickettsiae. In brief, the vector tropism of rickettsiae species is basically consistent with their tropism toward cultured tick and insect cells. The mechanisms responsible for rickettsiae pathogenicity are also described. Recently, genomic analyses of rickettsiae have revealed that they possess several genes that are homologous to those affecting the pathogenicity of other bacteria. Analyses comparing the genomes of pathogenic and non-pathogenic strains of rickettsiae have detected many factors that are related to rickettsial pathogenicity. It is also known that a reduction in the rickettsial genome has occurred during the course of its evolution. Interestingly, Rickettsia species with small genomes, such as Rickettsia prowazekii, are more pathogenic to humans than those with larger genomes. This review also examines the growth kinetics of pathogenic and non-pathogenic species of SFG rickettsiae (SFGR) in mammalian cells. The growth of non-pathogenic species is restricted in these cells, which is mediated, at least in part, by autophagy. The superinfection of non-pathogenic rickettsiae-infected cells with pathogenic rickettsiae results in an elevated yield of the non-pathogenic rickettsiae and the growth of the pathogenic rickettsiae. Autophagy is restricted in these cells. These results are discussed in this review.

Uchiyama T

2012-01-01

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Approaches to Subunit Vaccines against the Typhus Rickettsiae, Rickettsia typhi and Rickettsia prowazekii.  

Science.gov (United States)

We attempted to identify and purify those antigen components from Rickettsia typhi and Rickettsia prowazekii that are protective in forms which are both highly immunogenic and nontoxic. Subunit vaccines have obvious appeal in terms of purity and standardi...

G. A. Dasch J. P. Burans M. E. Dobson F. M. Rollwagen J. Misiti

1984-01-01

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Seroprevalence of Rickettsia bellii and Rickettsia felis in dogs, São José dos Pinhais, State of Paraná, Brazil Soroprevalência de Rickettsia bellii e Rickettsia felis em cães, São José dos Pinhais, Paraná, Brasil  

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Full Text Available Brazilian spotted fever (BSF) is a vector-borne zoonosis caused by Rickettsia rickettsii bacteria. Dogs can be host sentinels for this bacterium. The aim of the study was to determine the presence of antibodies against Rickettsia spp. in dogs from the city of São José dos Pinhais, State of Paraná, Southern Brazil, where a human case of BSF was first reported in the state. Between February 2006 and July 2007, serum samples from 364 dogs were collected and tested at 1:64 dilutions by indirect immunofluorescence assay (IFA) against R. rickettsii and R. parkeri. All sera that reacted at least to one of Rickettsia species were tested against the six main Rickettsia species identified in Brazil: R. rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii and R. felis. Sixteen samples (4.4%) reacted to at least one Rickettsia species. Among positive animals, two dogs (15.5%) showed suggestive titers for R. bellii exposure. One sample had a homologous reaction to R. felis, a confirmed human pathogen. Although Rickettsia spp. circulation in dogs in the area studied may be considered at low prevalence, suggesting low risk of human infection, the present data demonstrate for the first time the exposure of dogs to R. bellii and R. felis in Southern Brazil.A febre maculosa brasileira (FMB) é uma zoonose veiculada por carrapatos e causada pela bactéria Rickettsia rickettsii, podendo os cães ser hospedeiros sentinelas para essa bactéria. O objetivo do estudo foi determinar a presença de anticorpos contra Rickettsia spp. em cães de São José dos Pinhais, estado do Paraná, Sul do Brasil. Entre fevereiro de 2006 e julho de 2007, amostras séricas de 364 cães foram coletadas e testadas na diluição de 1:64 por Reação de Imunofluorescência Indireta (RIFI) contra R. rickettsii e R. parkeri. Todos os soros reagentes para pelo menos uma espécie de Rickettsia foram testados contra as seis principais espécies de Rickettsia identificadas no Brasil: R. rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii e R. felis. Dezesseis amostras (4,4%) reagiram para pelo menos uma espécie de Rickettsia. Dos animais positivos, dois cães (15,5%) apresentaram títulos sugestivos de exposição a R. bellii. Uma amostra apresentou reação homóloga frente à R. felis, um agente patogênico confirmado para seres humanos. Muito embora os resultados demonstrem uma baixa prevalência de Rickettsia spp. em cães, sugerindo um baixo risco de infecção humana, este estudo relatou pela primeira vez a evidência de exposição a R. bellii e R. felis em cães no Sul do Brasil.

Fernanda Silva Fortes; Iara Silveira; Jonas Moraes-Filho; Ronaldo Viana Leite; José Edivaldo Bonacim; Alexander Welker Biondo; Marcelo Bahia Labruna; Marcelo Beltrão Molento

2010-01-01

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Seroprevalence of Rickettsia bellii and Rickettsia felis in dogs, São José dos Pinhais, State of Paraná, Brazil/ Soroprevalência de Rickettsia bellii e Rickettsia felis em cães, São José dos Pinhais, Paraná, Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A febre maculosa brasileira (FMB) é uma zoonose veiculada por carrapatos e causada pela bactéria Rickettsia rickettsii, podendo os cães ser hospedeiros sentinelas para essa bactéria. O objetivo do estudo foi determinar a presença de anticorpos contra Rickettsia spp. em cães de São José dos Pinhais, estado do Paraná, Sul do Brasil. Entre fevereiro de 2006 e julho de 2007, amostras séricas de 364 cães foram coletadas e testadas na diluição de 1:64 por Reação (more) de Imunofluorescência Indireta (RIFI) contra R. rickettsii e R. parkeri. Todos os soros reagentes para pelo menos uma espécie de Rickettsia foram testados contra as seis principais espécies de Rickettsia identificadas no Brasil: R. rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii e R. felis. Dezesseis amostras (4,4%) reagiram para pelo menos uma espécie de Rickettsia. Dos animais positivos, dois cães (15,5%) apresentaram títulos sugestivos de exposição a R. bellii. Uma amostra apresentou reação homóloga frente à R. felis, um agente patogênico confirmado para seres humanos. Muito embora os resultados demonstrem uma baixa prevalência de Rickettsia spp. em cães, sugerindo um baixo risco de infecção humana, este estudo relatou pela primeira vez a evidência de exposição a R. bellii e R. felis em cães no Sul do Brasil. Abstract in english Brazilian spotted fever (BSF) is a vector-borne zoonosis caused by Rickettsia rickettsii bacteria. Dogs can be host sentinels for this bacterium. The aim of the study was to determine the presence of antibodies against Rickettsia spp. in dogs from the city of São José dos Pinhais, State of Paraná, Southern Brazil, where a human case of BSF was first reported in the state. Between February 2006 and July 2007, serum samples from 364 dogs were collected and tested at 1:64 (more) dilutions by indirect immunofluorescence assay (IFA) against R. rickettsii and R. parkeri. All sera that reacted at least to one of Rickettsia species were tested against the six main Rickettsia species identified in Brazil: R. rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii and R. felis. Sixteen samples (4.4%) reacted to at least one Rickettsia species. Among positive animals, two dogs (15.5%) showed suggestive titers for R. bellii exposure. One sample had a homologous reaction to R. felis, a confirmed human pathogen. Although Rickettsia spp. circulation in dogs in the area studied may be considered at low prevalence, suggesting low risk of human infection, the present data demonstrate for the first time the exposure of dogs to R. bellii and R. felis in Southern Brazil.

Fortes, Fernanda Silva; Silveira, Iara; Moraes-Filho, Jonas; Leite, Ronaldo Viana; Bonacim, José Edivaldo; Biondo, Alexander Welker; Labruna, Marcelo Bahia; Molento, Marcelo Beltrão

2010-12-01

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Rickettsia parkeri in Argentina.  

UK PubMed Central (United Kingdom)

Clinical reports of an eschar-associated rickettsiosis in the Paraná River Delta of Argentina prompted an evaluation of Amblyomma triste ticks in this region. When evaluated by PCR, 17 (7.6%) of 223 questing adult A. triste ticks, collected from 2 sites in the lower Paraná River Delta, contained DNA of Rickettsia parkeri.

Nava S; Elshenawy Y; Eremeeva ME; Sumner JW; Mastropaolo M; Paddock CD

2008-12-01

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Febre maculosa: isolamento de Rickettsia em amostra de biópsia de pele Spotted fever: Rickettsia isolation in skin biopsy sample  

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Full Text Available Presença de Rickettsia na pele de doente de Febre Maculosa foi evidenciada por inoculação intraperitoneal em cobaio. O diagnóstico sorológico por imunoflüorescência indireta revelou diferença de título de anticorpos específicos para Rickettsia rickettsii, de 4 vezes entre a 1º e a 3º amostra. Imunoglobulina M (IgM) específica foi detectada nas amostras de sangue, evidência de infecção em atividade ou recente. Foi também detectada a presença de anticorpos específicos para R. rickettsii no soro dos cobaios inoculados.A 2 years old child living in an area of the State of São Paulo, known in the past as endemic for rickettsiosis developed clinical evidences of spotted fever after a tick bite. Rickettsiae were isolated from guinea pigs inoculated with a skin homogenate. In sera tested by indirect immunofluorescence with Rickettsia rickettsii standard antigen, IgG specific antibody titers raised from 1:512 in the first sample to 1:2048 in the third one; IgM specific antibody titer was 1:128 in the three samples. Also positive were sera obtained from the inoculated guinea pigs. In the last 20 years no other case of rickettsial spotted fever has been confirmed by isolation of the agent in Brasil. To our knowlwdge, there are no previous reports of isolation of Rickettsiae through inoculation of skin biopsy homogenates.

Heloisa Helana B. Melles; Silvia Colombo; Marcos Vinícius da Silva

1992-01-01

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Febre maculosa: isolamento de Rickettsia em amostra de biópsia de pele/ Spotted fever: Rickettsia isolation in skin biopsy sample  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Presença de Rickettsia na pele de doente de Febre Maculosa foi evidenciada por inoculação intraperitoneal em cobaio. O diagnóstico sorológico por imunoflüorescência indireta revelou diferença de título de anticorpos específicos para Rickettsia rickettsii, de 4 vezes entre a 1º e a 3º amostra. Imunoglobulina M (IgM) específica foi detectada nas amostras de sangue, evidência de infecção em atividade ou recente. Foi também detectada a presença de anticorpos específicos para R. rickettsii no soro dos cobaios inoculados. Abstract in english A 2 years old child living in an area of the State of São Paulo, known in the past as endemic for rickettsiosis developed clinical evidences of spotted fever after a tick bite. Rickettsiae were isolated from guinea pigs inoculated with a skin homogenate. In sera tested by indirect immunofluorescence with Rickettsia rickettsii standard antigen, IgG specific antibody titers raised from 1:512 in the first sample to 1:2048 in the third one; IgM specific antibody titer was 1: (more) 128 in the three samples. Also positive were sera obtained from the inoculated guinea pigs. In the last 20 years no other case of rickettsial spotted fever has been confirmed by isolation of the agent in Brasil. To our knowlwdge, there are no previous reports of isolation of Rickettsiae through inoculation of skin biopsy homogenates.

Melles, Heloisa Helana B.; Colombo, Silvia; Silva, Marcos Vinícius da

1992-02-01

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Rickettsia parkeri Rickettsiosis, Argentina.  

UK PubMed Central (United Kingdom)

Rickettsia parkeri, a recently identified cause of spotted fever rickettsiosis in the United States, has been found in Amblyomma triste ticks in several countries of South America, including Argentina, where it is believed to cause disease in humans. We describe the clinical and epidemiologic characteristics of 2 patients in Argentina with confirmed R. parkeri infection and 7 additional patients with suspected R. parkeri rickettsiosis identified at 1 hospital during 2004-2009. The frequency and character of clinical signs and symptoms among these 9 patients closely resembled those described for patients in the United States (presence of an inoculation eschar, maculopapular rash often associated with pustules or vesicles, infrequent gastrointestinal manifestations, and relatively benign clinical course). Many R. parkeri infections in South America are likely to be misdiagnosed as other infectious diseases, including Rocky Mountain spotted fever, dengue, or leptospirosis.

Romer Y; Seijo AC; Crudo F; Nicholson WL; Varela-Stokes A; Lash RR; Paddock CD

2011-07-01

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Rickettsiae in Gulf Coast ticks, Arkansas, USA.  

UK PubMed Central (United Kingdom)

To determine the cause of spotted fever cases in the southern United States, we screened Gulf Coast ticks (Amblyomma maculatum) collected in Arkansas for rickettsiae. Of the screened ticks, 30% had PCR amplicons consistent with Rickettsia parkeri or Candidatus Rickettsia amblyommii.

Trout R; Steelman CD; Szalanski AL; Williamson PC

2010-05-01

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Susceptibility of Ticks of the Superfamily Ixodoidea to Rickettsia Prowazeki.  

Science.gov (United States)

Susceptibility of ticks to Rickettsia prowazekii was tested experimentally. For infection of ticks they were either placed on infected guinea pigs or injected with rickettsia. Ticks H. anatolicum, D. pictus, A canestrinii picked up rickettsia during feedi...

I. M. Grokhovskaya V. F. Ignatovich V. E. Sidorov

1968-01-01

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Rickettsia felis in Fleas, Germany  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Among 310 fleas collected from dogs and cats in Germany, Rickettsia felis was detected in all specimens (34) of Archaeopsylla erinacei (hedgehog flea) and in 9% (24/226) of Ctenocephalides felis felis (cat flea). R. helvetica was detected in 1 Ceratophyllus gallinae (hen flea).

Gilles, Jérémie; Just, Frank Thomas; Silaghi, Cornelia; Pradel, Ingrid; Passos, Lygia Maria Friche; Lengauer, Heidi

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Ganglionar nervous cells and telocytes in the pancreas of Octodon degus: Extra and intrapancreatic ganglionar cells and telocytes in the degus.  

UK PubMed Central (United Kingdom)

This study shows for the first time the presence of intra and extrapancreatic ganglionar neurons and telocytes in Octodon degus such as those described in human and guinea pig pancreas. Pancreatic ganglionar neurons were identified by their histological characteristics as well as their positive immunostaining with mouse anti-human neuron specific enolase (NSE) antibody. Somatostatin secreting delta cells (D cells) in the islets of Langerhans were identified by positive immunostaining with rabbit antihuman polyclonal somatostatin antibody. Electron microscopy evidenced the presence of some unmyelinated axons in the interlobular spaces or septa, usually located adjacent to blood vessels and the exocrine epithelial ducts. The presence of telocytes with at least 2 telopodes was observed in the interlobular space, frequently in close spatial relationship with blood vessels and nerve endings. Telocytes were often observed in the vicinity or even in close proximity with both secretory acini and exocrine epithelial ducts and regulatory nerves and blood vessel apparatuses. A possible framework has been put forward within which such structures might contribute to elicit physiological responses in the pancreas. Further studies of synaptic interactions within and between pancreatic neuron cells are needed to help clarify the morphological results reported here. A broad overview of the field of neurogastroenterology with focus on the pancreas of O. degus related to the enteric nervous system (ENS) is provided in order to help design future studies on the connections of specific neurons forming pancreatic pathways, their neurotransmission processes and how disruption of these pathways may contribute to pancreatic disease.

Bosco C; Díaz E; Gutiérrez R; González J; Pérez J

2013-10-01

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Isolamento de Rickettsia em cultura de células vero Isolation of Rickettsia in vero cell culture  

Directory of Open Access Journals (Sweden)

Full Text Available Embora o diagnóstico da febre maculosa baseie-se em sinais e sintomas característicos, o mesmo requer confirmação laboratorial, pois existem alguns diagnósticos diferenciais possíveis como meningococcemia, leptospirose, infecção por enterovírus e febre tifóide. A confirmação laboratorial pode ser feita através da pesquisa de anticorpos específicos, possível somente alguns dias após o aparecimento da doença, através do isolamento do agente em amostras de sangue e/ou biópsia de pele, e ainda, de amostras de carrapatos coletados do paciente ou de animais reservatório. O isolamento a partir de sangue ou biópsia de pele resulta em diagnóstico precoce da doença, pois na fase de rickettsemia ainda não há anticorpos detectáveis no sangue. Assim, com o objetivo de facilitar o diagnóstico precoce da febre maculosa, estabelecemos um método de isolamento de rickettsia em cultura de células vero. Para a padronização foi inoculada amostra padrão de Rickettsia rickettsii, cepa Sheyla Smith, cedida pelo CDC. A identificação foi feita através da reação de imunofluorescência indireta. A presença de microrganismos verdes fluorescentes visualizados no interior do citoplasma das células caracterizou o crescimento do agente. Posteriormente, a metodologia foi confirmada pelo isolamento do agente da febre maculosa em amostras de biópsia de pele de paciente proveniente de área endêmica no Estado de São Paulo, bem como, de amostras de carrapato do gênero Amblyomma, considerado o reservatório e transmissor da doença no Brasil.The diagnosis of spotted fever is based on characteristic signs and symptoms but requires laboratorial confirmation because of the possible differencial diagnosis from other diseases like leptospirosis, enterovirosis, meningococcemia and tiphoid fever. Laboratorial confirmation may be done by detection of specific antibodies which is possible only 5-10 days after the onset of the symptoms or by the isolation of Rickettsiae from blood and/or skin biopsy and from ticks collected in the patient or in the animal reservoir. The isolation of Rickettsiae from blood or skin biopsy results in an early diagnosis of spotted fever since in the rickettsiemic phase of the disease there is no detectable level of antibodies in the serum. With the purpose of facilitating the diagnosis of Spotted Fever we have standardized the isolation of Rickettsiae in cell culture by a method that is less time consuming and that reduces the biological risks than isolation in guinea pigs. vero cell cultures were inoculated with the Sheyla Smith strain of Rickettsia rickettsii provided by CDC (Atlanta-USA). The identification was performed by indirect immunofluorescence technique. The presence of green fluorescent organisms characterized the growth of the agent. Ulterior confirmation of the methodology was done by isolation of the spotted fever agent from skin biopsy of a patient from an endemic area and from Amblyomma ticks that are the reservoir and vector of the Brazilian spotted fever.

Heloisa Helena Barbosa Melles; Silvia Colombo; Elba Regina Sampaio de Lemos

1999-01-01

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Rickettsia felis: un patógeno emergente en Latinoamérica/ Rickettsia felis: an emerging pathogen in Latin America  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El primer caso humano infectado con Rickettsia felis fue descrito en un paciente diagnosticado con tifus murino en Estados Unidos en 1994. Los reportes acerca de la presencia de R. felis se han incrementado en los últimos años y ya se ha reportado en la mayoría de los países de América Latina. Los síntomas y signos de la enfermedad causada por R. felis son inespecíficos y es importante que cada país lo incluya en el diagnóstico diferencial con respecto a otras enfermedades que tienen las mismas manifestaciones clínicas. Abstract in english The first human case of Rickettsia felis was described in 1994, in a patient diagnosed with murine typhus in the United States. Reports about the presence of R. felis have increased in the last years, and it has been reported in most countries of Latin America. Signs and symptoms of disease caused by R. felis are unspecific, and it is important for each country to include it in the differential diagnosis with other diseases that show the same clinical manifestations.

Zavala Castro, Jorge E

2013-07-01

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Evolution and diversity of Rickettsia bacteria  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Rickettsia are intracellular symbionts of eukaryotes that are best known for infecting and causing serious diseases in humans and other mammals. All known vertebrate-associated Rickettsia are vectored by arthropods as part of their life-cycle, and many other Rickettsia are found exclusively in arthropods with no known secondary host. However, little is known about the biology of these latter strains. Here, we have identified 20 new strains of Rickettsia from arthropods, and constructed a multi-gene phylogeny of the entire genus which includes these new strains. Results We show that Rickettsia are primarily arthropod-associated bacteria, and identify several novel groups within the genus. Rickettsia do not co-speciate with their hosts but host shifts most often occur between related arthropods. Rickettsia have evolved adaptations including transmission through vertebrates and killing males in some arthropod hosts. We uncovered one case of horizontal gene transfer among Rickettsia, where a strain is a chimera from two distantly related groups, but multi-gene analysis indicates that different parts of the genome tend to share the same phylogeny. Conclusion Approximately 150 million years ago, Rickettsia split into two main clades, one of which primarily infects arthropods, and the other infects a diverse range of protists, other eukaryotes and arthropods. There was then a rapid radiation about 50 million years ago, which coincided with the evolution of life history adaptations in a few branches of the phylogeny. Even though Rickettsia are thought to be primarily transmitted vertically, host associations are short lived with frequent switching to new host lineages. Recombination throughout the genus is generally uncommon, although there is evidence of horizontal gene transfer. A better understanding of the evolution of Rickettsia will help in the future to elucidate the mechanisms of pathogenicity, transmission and virulence.

Weinert Lucy A; Werren John H; Aebi Alexandre; Stone Graham N; Jiggins Francis M

2009-01-01

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Rickettsia helvetica in Dermacentor reticulatus Ticks  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report on the molecular evidence that Dermacentor reticulatus ticks in Croatia are infected with Rickettsia helvetica (10%) or Rickettsia slovaca (2%) or co-infected with both species (1%). These findings expand the knowledge of the geographic distribution of R. helvetica and D. reticulatus ticks...

Dobec, Marinko; Golubic, Dragutin; Punda-Polic, Volga; Kaeppeli, Franz; Sievers, Martin

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Rickettsia parkeri in Amblyomma triste from Uruguay  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Our goal was to detect whether spotted fever group Rickettsia are found in the suspected vector of rickettsioses, Amblyomma triste, in Uruguay. Rickettsia parkeri was detected in A. triste, which suggests that this species could be considered a pathogenic agent responsible for human rickettsioses in...

Venzal, José M.; Portillo, Aránzazu; Estrada-Peña, Agustín; Castro, Oscar; Cabrera, Perla A.; Oteo, José A.

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Neuroprotección de las células ganglionares de la retina Retinal ganglion cell neuroprotection in culture  

Directory of Open Access Journals (Sweden)

Full Text Available Objetivo: Estudiar la supervivencia de las células ganglionares de la retina (CGR) de cerdo en cultivo, analizando el posible efecto neuroprotector de las células de Müller de la retina (CMR) y del factor neurotrófico derivado del cerebro (BDNF). Métodos: Las retinas de cerdo adulto fueron disociadas y cultivadas en diferentes condiciones: 1) sobre sustrato de laminina/poli-D-lisina en medio de cultivo químicamente definido; 2) sobre sustrato de laminina/poli-D-lisina en medio químicamente definido al que se añadió BDNF; 3) sobre monocapas de CMR en medio químicamente definido; 4) sobre sustrato de laminina/poli-D-lisina en medio condicionado procedente del sobrenadante de las CMR. Las CGR fueron identificadas mediante inmunocitoquímica, utilizando anticuerpos contra el neurofilamento de 68 kDa, y observadas con un microscopio de fluorescencia. Se analizó la supervivencia para cada condición de cultivo y se clasificaron las CGR en función de su tamaño y del número y longitud de las neuritas. Resultados: La supervivencia de las CGR aumentó cuando las células fueron cultivadas sobre monocapas confluentes de CMR o en medio condicionado. Estas condiciones produjeron un incremento en el área media de las células y un aumento en el número de neuritas emitidas por cada célula, así como en la longitud de las neuritas. Cuando el medio de cultivo se suplementó con BDNF no se obtuvo ningún efecto sobre la supervivencia de las CGR aunque aumentó el tamaño, y el número y longitud de sus neuritas. Conclusión: Nuestro trabajo demuestra que algún/os factor/es secretados por las células de Müller tienen un efecto neuroprotector sobre las CGR in vitro. El BDNF produce también un incremento en el área media de las células y favorece la formación de neuritas, sin embargo no aumenta la supervivencia.Purpose: To study the pig retinal ganglion cell (RGC) survival in culture, analysing the possible neuroprotective effect of retinal Müller glia (RMG) and brain-derived neurotrophic factor (BDNF). Methods: Adult pig retina were dissociated and cultured under different conditions: 1) on laminin/poly-D-lysine-coated coverslips in chemically defined medium (CDM); 2) on laminin/poly-D-lysine-coated coverslips in CMD supplemented with BDNF; 3) on confluent monolayer cultures of RMG in CDM; 4) on laminin/poly-D-lysine substrate in conditioned medium obtained from RMG. RGCs were identified by immunocytochemistry using antibody against 68 kDa neurofilament and observed under an fluorescent microscope. RGCs were classified on the basis of the size, number and length of neurites, and their survival was assayed for each treatment. Results: Confluent RMG substrates and RMG conditioned medium significantly increased the survival of cultured pig RGC. Moreover these two conditions increased the mean area of RGCs and enhanced neurite growth and elongation. Addition of BDNF to culture medium did not modify survival but increased RGC size, neurite number and neurite length. Conclusions: These findings demonstrate that factor(s) secreted by RMG exert beneficial effects on adult RGC survival and neurite regeneration in vitro, and might constitute important agent(s) for RGC neuroprotection. BDNF also increases the mean area of RGCs and enhances neurite growth but it does not increase the survival of RGCs.

M García; J Ruiz Ederra; E Hernández Barbáchano; JA Urcola; J Bilbao; J Araiz; JA Durán; E Vecino

2003-01-01

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Neuroprotección de las células ganglionares de la retina/ Retinal ganglion cell neuroprotection in culture  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Objetivo: Estudiar la supervivencia de las células ganglionares de la retina (CGR) de cerdo en cultivo, analizando el posible efecto neuroprotector de las células de Müller de la retina (CMR) y del factor neurotrófico derivado del cerebro (BDNF). Métodos: Las retinas de cerdo adulto fueron disociadas y cultivadas en diferentes condiciones: 1) sobre sustrato de laminina/poli-D-lisina en medio de cultivo químicamente definido; 2) sobre sustrato de laminina/poli-D-lisi (more) na en medio químicamente definido al que se añadió BDNF; 3) sobre monocapas de CMR en medio químicamente definido; 4) sobre sustrato de laminina/poli-D-lisina en medio condicionado procedente del sobrenadante de las CMR. Las CGR fueron identificadas mediante inmunocitoquímica, utilizando anticuerpos contra el neurofilamento de 68 kDa, y observadas con un microscopio de fluorescencia. Se analizó la supervivencia para cada condición de cultivo y se clasificaron las CGR en función de su tamaño y del número y longitud de las neuritas. Resultados: La supervivencia de las CGR aumentó cuando las células fueron cultivadas sobre monocapas confluentes de CMR o en medio condicionado. Estas condiciones produjeron un incremento en el área media de las células y un aumento en el número de neuritas emitidas por cada célula, así como en la longitud de las neuritas. Cuando el medio de cultivo se suplementó con BDNF no se obtuvo ningún efecto sobre la supervivencia de las CGR aunque aumentó el tamaño, y el número y longitud de sus neuritas. Conclusión: Nuestro trabajo demuestra que algún/os factor/es secretados por las células de Müller tienen un efecto neuroprotector sobre las CGR in vitro. El BDNF produce también un incremento en el área media de las células y favorece la formación de neuritas, sin embargo no aumenta la supervivencia. Abstract in english Purpose: To study the pig retinal ganglion cell (RGC) survival in culture, analysing the possible neuroprotective effect of retinal Müller glia (RMG) and brain-derived neurotrophic factor (BDNF). Methods: Adult pig retina were dissociated and cultured under different conditions: 1) on laminin/poly-D-lysine-coated coverslips in chemically defined medium (CDM); 2) on laminin/poly-D-lysine-coated coverslips in CMD supplemented with BDNF; 3) on confluent monolayer cultures o (more) f RMG in CDM; 4) on laminin/poly-D-lysine substrate in conditioned medium obtained from RMG. RGCs were identified by immunocytochemistry using antibody against 68 kDa neurofilament and observed under an fluorescent microscope. RGCs were classified on the basis of the size, number and length of neurites, and their survival was assayed for each treatment. Results: Confluent RMG substrates and RMG conditioned medium significantly increased the survival of cultured pig RGC. Moreover these two conditions increased the mean area of RGCs and enhanced neurite growth and elongation. Addition of BDNF to culture medium did not modify survival but increased RGC size, neurite number and neurite length. Conclusions: These findings demonstrate that factor(s) secreted by RMG exert beneficial effects on adult RGC survival and neurite regeneration in vitro, and might constitute important agent(s) for RGC neuroprotection. BDNF also increases the mean area of RGCs and enhances neurite growth but it does not increase the survival of RGCs.

García, M; Ruiz Ederra, J; Hernández Barbáchano, E; Urcola, JA; Bilbao, J; Araiz, J; Durán, JA; Vecino, E

2003-03-01

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Molecular detection of Rickettsia bellii, Rickettsia montanensis, and Rickettsia rickettsii in a Dermacentor variabilis tick from nature.  

UK PubMed Central (United Kingdom)

Rickettsial diseases, such as Rocky Mountain spotted fever, pose a public health threat because of humans' interrelationship with common arthropod species, such as ticks, mites, fleas, and lice. Individuals may come in contact with these vectors of disease on a fairly regular basis either directly or indirectly through pets or wildlife species, at home or in recreational areas. Therefore, it is of vital importance to know and understand the geographical distribution and prevalence of disease and rickettsial-infected arthropods. We analyzed Dermacentor variabilis ticks from nature found positive for Rickettsia sp. to determine the specific species present. Rickettsiae were detected through a 17-kDa surface antigen seminested PCR. Seminested PCR represents a sensitive and specific molecular technique in which to identify the presence of bacteria within arthropod hosts. Through sequence analysis of this gene, three Rickettsia species, Rickettsia bellii, Rickettsia montanensis, and Rickettsia rickettsii, were detected in a single tick specimen. Further molecular analyses of the 17-kDa surface antigen and the citrate synthase gene were also performed to support this finding. This is the first report of the detection of multiple Rickettsia species from a single D. variabilis tick in nature.

Carmichael JR; Fuerst PA

2010-03-01

 
 
 
 
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Genetic characterization of Candidatus Rickettsia vini, a new rickettsia amplified in ticks from La Rioja, Spain.  

UK PubMed Central (United Kingdom)

A total of 222 ticks removed from birds in La Rioja (Spain) were screened for spotted fever group rickettsia species using ompA PCR assays. Rickettsia monacensis (n=1) and R. sibirica (n=1) were detected. Apart from that, 27 out of 29 Ixodes spp. DNA extracts that tested positive for ompA did not match with any validated spotted fever group rickettsia. Multilocus sequence typing for 16S rRNA, gltA, ompB, sca4, and 17-kDa antigen genes was performed, and R. heilongjiangensis was found to be the nearest validly published spotted fever group rickettsia. Based on genetic criteria agreed by experts, this genotype can be classified as a new Candidatus Rickettsia sp. and was named Candidatus Rickettsia vini.

Palomar AM; Portillo A; Santibáñez P; Santibáñez S; García-Álvarez L; Oteo JA

2012-12-01

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PCR MÚLTIPLE ANIDADA PARA DETECCIÓN DE FITOPLASMAS Y RICKETTSIA ASOCIADOS CON LOS SÍNTOMAS DEL COGOLLO ARREPOLLADO (BTS) EN PAPAYO/ NESTED PCR MULTIPLEX FOR THE DETECTION OF THE PHYTOPLASMAS AND RICKETTSIA ASSOCIATED WITH BUNCHY TOP SYMPTOM (BTS) IN PAPAYO  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Recientemente, los grupos fitoplasmas 16SrI «Candidatus Phytoplasma asteris»,16SrII «Candidatus Phytoplasma aurantifolia» y rickettsia se asociaron a síntomas del cogollo arrepollado (BTS) del papayo en Cuba. El ADN de muestras de plantas de papayo positivas a fitoplasmas y rickettsia se empleó para optimizar y evaluar un ensayo de PCR múltiple anidada. Se usaron los iniciadores de PCR genéricos para fitoplamas R16mF2/R16mR1en la primera amplificación y en la seg (more) unda amplificación una mezcla PBTF1/PBTR1 (específicos para rickettsia) y R16F2n/BPVNr/p86r (específicos para los grupos de fitoplasmas 16SrI y 16SrII). El ensayo de diagnóstico por PCR múltiple anidado permitió la detección simultánea de fitoplasmas y rickettsia en muestras de plantas de papayo de condiciones de campo. Abstract in english Recently, the phytoplasmas groups 16SrI `Candidatus Phytoplasma aurantifolia' and 16SrII group `Candidatus Phytoplasma asteris' and rickettsia were associated with Bunchy Top Symptoms (BTS) of papayo in Cuba. The ADN samples from papaya plants positive to phytoplasma and rickettsia were used for evaluate and optimize nPCR multiplex. Generic primers for amplification of phytoplasma R16mF2/R16mR1 were used in the first reaction. A mixture composed of PBTF1/PBTR1and R16F2n/B (more) PVNr/p86r for rickettsia and phytoplasma (16SrI and 16SrII groups) amplifications were used in the second reaction. The diagnostic assay by the nPCR multiplex permitted the simultaneous detection of phytoplasmas and rickettsias in samples of papaya plants from the field.

Acosta, K; Martínez, Y; Zamora, L; Fernández, A; Santos-Cervantes, M.E; Leyva-López, N.E

2011-12-01

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Simple method to differentiate among Rickettsia species.  

UK PubMed Central (United Kingdom)

In this work we present a new option to identify 11 rickettsial species that cause human rickettsioses, with some advantages over the previous methods described. Using rickettsial isolates from 11 Rickettsia species as a sample, we used the polymerase chain reaction to amplify a 990- to 1,000-bp DNA fragment from the ompB gene, common for the 11 Rickettsia species analyzed in this study, which were digested with AluI restriction enzyme to obtain different digestion patterns. This restriction pattern can be visualized using a polyacrylamide gel electrophoresis technique. Using this method we could differentiate between the 11 Rickettsia species analyzed regardless of the group to which the Rickettsia belonged. We developed a simple method to identify 11 Rickettsia species which cause human rickettsioses using polymerase chain reaction and restriction fragment length polymorphism techniques with the advantage that it only needs one amplicon and only one restriction enzyme to obtain the restriction pattern. The identification of the species infecting vectors, reservoirs, and humans is essential to establish the ecological and behavioral ecosystem involved in its maintenance and transmission in nature in the specific region where the pathogen is circulating. This method is very helpful to identify Rickettsia species in a short time.

Peniche-Lara G; Zavala-Velazquez J; Dzul-Rosado K; Walker DH; Zavala-Castro J

2013-01-01

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In vitro susceptibilities of Rickettsia rickettsii and Rickettsia conorii to roxithromycin and pristinamycin.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In vitro susceptibilities of Rickettsia rickettsii and Rickettsia conorii to roxithromycin, pristinamycin, and the pristinamycin compounds, P1 and P2, were determined by a dye uptake assay and a plaque assay. The MICs were 1 microgram/ml for roxithromycin, 2 micrograms/ml for pristinamycin, greater ...

Drancourt, M; Raoult, D

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Spotted fever group rickettsiae in ticks feeding on humans in northwestern Spain: is Rickettsia conorii vanishing?  

UK PubMed Central (United Kingdom)

During a 7-year study, we identified and analyzed by PCR 4,049 ticks removed from 3,685 asymptomatic patients in Castilla y León (northwestern Spain). A total of 320 ticks (belonging to 10 species) were PCR-positive for rickettsiae. Comparison of amplicon sequences in databases enabled us to identify eight different spotted fever group (SFG) rickettsiae: Rickettsia slovaca, Rickettsia sp. IRS3/IRS4, R. massiliae/Bar29, R. aeschlimannii, Rickettsia sp. RpA4/DnS14, R. helvetica, Rickettsia sp. DmS1, and R. conorii. Although Mediterranean spotted fever (MSF) is an endemic disease in Castilla y León, R. conorii was found in only one Rhipicephalus sanguineus tick, whereas other pathogenic SFG rickettsiae were much more prevalent in the same area. Our data suggest that in Castilla y León, many MSF or MSF-like cases attributed to R. conorii could have been actually caused by other SFG rickettsiae present in ticks biting people in this region of Spain.

Fernández-Soto P; Pérez-Sánchez R; Alamo-Sanz R; Encinas-Grandes A

2006-10-01

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Spotted fever group rickettsiae in ticks feeding on humans in northwestern Spain: is Rickettsia conorii vanishing?  

Science.gov (United States)

During a 7-year study, we identified and analyzed by PCR 4,049 ticks removed from 3,685 asymptomatic patients in Castilla y León (northwestern Spain). A total of 320 ticks (belonging to 10 species) were PCR-positive for rickettsiae. Comparison of amplicon sequences in databases enabled us to identify eight different spotted fever group (SFG) rickettsiae: Rickettsia slovaca, Rickettsia sp. IRS3/IRS4, R. massiliae/Bar29, R. aeschlimannii, Rickettsia sp. RpA4/DnS14, R. helvetica, Rickettsia sp. DmS1, and R. conorii. Although Mediterranean spotted fever (MSF) is an endemic disease in Castilla y León, R. conorii was found in only one Rhipicephalus sanguineus tick, whereas other pathogenic SFG rickettsiae were much more prevalent in the same area. Our data suggest that in Castilla y León, many MSF or MSF-like cases attributed to R. conorii could have been actually caused by other SFG rickettsiae present in ticks biting people in this region of Spain. PMID:17114733

Fernández-Soto, Pedro; Pérez-Sánchez, Ricardo; Alamo-Sanz, Rufino; Encinas-Grandes, Antonio

2006-10-01

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Absence of Rickettsia rickettsii and occurrence of other spotted fever group rickettsiae in ticks from Tennessee.  

UK PubMed Central (United Kingdom)

Rocky Mountain spotted fever (RMSF) is the most common tick-borne illness in Tennessee. Little is known about the occurrence of R. rickettsii, the causative agent, in ticks in Tennessee. To better understand the prevalence and distribution of rickettsial agents in ticks, we tested 1,265 Amblyomma, Dermacentor, and Ixodes adult and nymphal ticks. Additionally, we tested 231 Amblyomma americanum larvae. Ticks were collected from 49 counties from humans, wild animals, domestic canines, and flannel drags. Spotted fever group rickettsiae (SFGR) DNA was detected by polymerase chain reaction (PCR) in 32% of adult and nymphal ticks. A total minimum infection rate of 85.63 was found in larval pools tested. Three rickettsial species, Rickettsia montana, Rickettsia amblyommii, and Rickettsia cooleyi were identified by molecular analysis. Rickettsia rickettsii was not detected. This study suggests that some RMSF cases reported in Tennessee may be caused by cross-reactivity with other SFGR antigenically related to R. rickettsii.

Moncayo AC; Cohen SB; Fritzen CM; Huang E; Yabsley MJ; Freye JD; Dunlap BG; Huang J; Mead DG; Jones TF; Dunn JR

2010-09-01

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Rickettsia bellii infecting Amblyomma sabanerae ticks in El Salvador.  

UK PubMed Central (United Kingdom)

Four Amblyomma sabanerae ticks collected from a turtle (Kinosternon sp.) in San Miguel, El Salvador, were found by molecular analysis to be infected by Rickettsia bellii. We provide the first report of Rickettsia bellii in Central America, and the first report of a Rickettsia species in El Salvador.

Barbieri AR; Romero L; Labruna MB

2012-07-01

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Amiloidose ganglionar mediastinal em paciente com sarcoidose Mediastinal lymph node amyloidosis in a patient with sarcoidosis  

Directory of Open Access Journals (Sweden)

Full Text Available Paciente masculino, 27 anos, com sintomas respiratórios, linfonodomegalia cervical anterior bilateral e hepatomegalia. Os estudos de imagem evidenciaram linfonodomegalia hilar bilateral e infiltrado pulmonar. O paciente foi submetido a biópsias pulmonar e hepática, que evidenciaram presença de granulomas não caseosos. Também foi submetido à biópsia de linfonodo hilar, que revelou a presença de material amilóide. Os achados clínicos, radiológicos e histopatológicos foram compatíveis com sarcoidose e amiloidose ganglionar. A associação entre sarcoidose e amiloidose é raramente descrita.A 27-year-old male patient presented with respiratory symptoms, bilateral enlargement of the cervical lymph nodes and enlarged liver. In the imaging studies, bilateral enlargement of the hilar nodes was observed, together with pulmonary infiltrate. The patient was submitted to lung and liver biopsies, which revealed noncaseating granulomas. The clinical, radiological and histopathological findings were consistent with sarcoidosis and lymph node amyloidosis. The combination of sarcoidosis and amyloidosis has rarely been reported.

Lilian Schade; Eliane Ribeiro Carmes; João Adriano de Barros

2007-01-01

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Large lymph node size harvested as prognostic factor in gastric cancer? ¿Es el diámetro ganglionar mayor un factor pronóstico en cáncer gástrico?  

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Full Text Available Objective: knowledge regarding prognostic factors in gastric cancer is essential to decide on single patient management. We aim to establish the value of large lymph node size in order to improve perioperative approach. Material and methods: charts of one hundred and twenty-eight consecutive patients undergoing gastrectomy for resectable gastric cancer were reviewed between January 1996 and December 2005. Patients were split in two groups according to large lymph node size harvested, group I, lymph node size ? 10 mm and group II, lymph node size > 10 mm. Overall five-year survival related to cancer were analyzed as a main endpoint. Prognostic factors as TNM classification and degree of differentiation have been considered. Results: there were no differences regarding age and gender (67.4 vs. 64; p = 0.34 and 66,1 vs. 68,1%; p = 0.27, respectively). Nevertheless, a significant difference has been found according to T1-T2 of TNM stage (78.1 vs. 39.1% p = Objetivo: valorar el interés del diámetro del ganglio mayor extirpado como factor pronóstico en los pacientes intervenidos por cáncer gástrico, para determinar si su detección puede ser un factor de interés en el periodo preoperatorio, para indicar tratamiento neoadyuvante. Material y métodos: se analiza un registro de 128 casos consecutivos de pacientes afectos de adenocarcinoma gástrico resecable, durante un periodo de 10 años en los que en el estudio anatomopatológico se determinó el diámetro del ganglio mayor aislado. Se estudia la relación del mismo con factores pronósticos universalmente aceptados, el grado de penetración, la presencia y extensión de metástasis ganglionares y el estadio TNM, y con la supervivencia a 5 años, estudiándose dos grupos, el grupo I compuesto por aquellos enfermos con diámetro menor o igual a 10 mm, y el grupo II con diámetros superiores a 10 mm. Resultados: no se han detectado diferencias estadísticas respecto a edad y sexo (67,4 vs. 64; p = 0,34 y 66,1 vs. 68,1%; p = 0,27, respectivamente). Existen diferencias significativas entre ambos grupos en el grado de penetración tumoral, T1-T2, (78,1% por 39,1%, p < 0,001), en el porcentaje de pacientes sin metástasis ganglionares (62,7 vs. 30,5%; p < 0,001), así como en el porcentaje de estadios precoces (Ia y Ib, 57,6% por 17,4, p < 0,001). La supervivencia global acumulada a los 60 meses fue significativa entre ambos grupos (p log-rank = 0,0003), aunque sin alcanzar significación estadística en los pacientes N+ (p < 0,006). Conclusiones: la relación del diámetro ganglionar mayor puede ser un factor pronóstico útil y junto con otros factores pronósticos facilitaría la valoración de quimioterapia neoadyuvante. Su detección mediante exploraciones complementarias adquiriría por consiguiente un mayor interés.

F. Espín; A. Bianchi; S. Llorca; L. Pulido; J. Feliu; J. de-la Cruz; E. Palomera; O. García; J. Remon; X. Suñol

2010-01-01

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Assessment of real-time PCR assay for detection of Rickettsia spp. and Rickettsia rickettsii in banked clinical samples.  

UK PubMed Central (United Kingdom)

Two novel real-time PCR assays were developed for the detection of Rickettsia spp. One assay detects all tested Rickettsia spp.; the other is specific for Rickettsia rickettsii. Evaluation using DNA from human blood and tissue samples showed both assays to be more sensitive than nested PCR assays currently in use at the CDC.

Kato CY; Chung IH; Robinson LK; Austin AL; Dasch GA; Massung RF

2013-01-01

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Transmission of Rickettsia slovaca and Rickettsia raoultii by male Dermacentor marginatus and Dermacentor reticulatus ticks to humans.  

UK PubMed Central (United Kingdom)

We analyzed rickettsial DNA of ticks from tick-borne lymphadenopathy (TIBOLA) patients. Dermacentor marginatus (9/17) and Dermacentor reticulatus (8/17) transmitted rickettsiae to a similar extent. Rickettsia raoultii was detected in more ticks than Rickettsia slovaca. We observed the development of TIBOLA symptoms after the bite of males of both tick species.

Földvári G; Rigó K; Lakos A

2013-07-01

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Transmission of Rickettsia slovaca and Rickettsia raoultii by male Dermacentor marginatus and Dermacentor reticulatus ticks to humans.  

Science.gov (United States)

We analyzed rickettsial DNA of ticks from tick-borne lymphadenopathy (TIBOLA) patients. Dermacentor marginatus (9/17) and Dermacentor reticulatus (8/17) transmitted rickettsiae to a similar extent. Rickettsia raoultii was detected in more ticks than Rickettsia slovaca. We observed the development of TIBOLA symptoms after the bite of males of both tick species. PMID:23602788

Földvári, Gábor; Rigó, Krisztina; Lakos, András

2013-04-18

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Rickettsia honei: a spotted fever group Rickettsia on three continents.  

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Rickettsia honei (also known as strain TT-118) has been detected on three continents. Originally isolated in Thailand in 1962 (and confirmed in 2001), it has also been detected on Flinders Island (Australia) in 1993 and in Texas (USA) in 1998. On each continent it has been associated with a different species of tick. The original isolate (Thai Tick Typhus strain TT-118) was from a pool of larval Ixodes and Rhipicephalus ticks. Later it was detected in I. granulatus from Rattus rattus. Its pathogenicity for humans has not yet been confirmed in Thailand, but it is possibly responsible for the Spotted Fever Group human rickettsiosis in Thailand. The strain from Texas (USA) was isolated from Amblyomma cajennense ticks taken from cattle. Its pathogenicity for humans has not yet been confirmed in Texas. However, this tick is known to bite humans. The strain from Flinders Island (Australia) described as R. honei, has been isolated from patients with "Flinders Island Spotted Fever" and from Aponomma hydrosauri ticks taken from blue-tongue lizards (Tiliqua nigrolutea), tiger snakes (Notechis ater humphreysi), and copperhead snakes (Austrelaps superbus) on Flinders Island. The ecology of R. honei in this location is unusual in that reptiles, rather than mammals, are the vertebrate hosts. PMID:12860601

Graves, Stephen; Stenos, John

2003-06-01

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Rickettsia honei: a spotted fever group Rickettsia on three continents.  

UK PubMed Central (United Kingdom)

Rickettsia honei (also known as strain TT-118) has been detected on three continents. Originally isolated in Thailand in 1962 (and confirmed in 2001), it has also been detected on Flinders Island (Australia) in 1993 and in Texas (USA) in 1998. On each continent it has been associated with a different species of tick. The original isolate (Thai Tick Typhus strain TT-118) was from a pool of larval Ixodes and Rhipicephalus ticks. Later it was detected in I. granulatus from Rattus rattus. Its pathogenicity for humans has not yet been confirmed in Thailand, but it is possibly responsible for the Spotted Fever Group human rickettsiosis in Thailand. The strain from Texas (USA) was isolated from Amblyomma cajennense ticks taken from cattle. Its pathogenicity for humans has not yet been confirmed in Texas. However, this tick is known to bite humans. The strain from Flinders Island (Australia) described as R. honei, has been isolated from patients with "Flinders Island Spotted Fever" and from Aponomma hydrosauri ticks taken from blue-tongue lizards (Tiliqua nigrolutea), tiger snakes (Notechis ater humphreysi), and copperhead snakes (Austrelaps superbus) on Flinders Island. The ecology of R. honei in this location is unusual in that reptiles, rather than mammals, are the vertebrate hosts.

Graves S; Stenos J

2003-06-01

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Identification of a novel uncultured Rickettsia species strain (Rickettsia species strain Tselenti) in Cyprus.  

UK PubMed Central (United Kingdom)

In a previous study conducted in Cyprus, various spotted fever group Rickettsia species were detected and identified in ticks by molecular analysis. Among them, a partially characterized Rickettsia species was detected in Hyalomma anatolicum excavatum and Rhipicephalus turanicus ticks. We report characterization of this rickettsial strain by using polymerase chain reaction sequencing analysis of partial citrate synthase A, outer membrane protein A, outer membrane protein B, and 17-kD protein genes. We propose a provisional name Rickettsia sp. strain Tselenti for this strain until it is isolated and further characterized.

Sandalakis V; Chochlakis D; Ioannou I; Psaroulaki A

2013-04-01

57

Identification of a novel uncultured Rickettsia species strain (Rickettsia species strain Tselenti) in Cyprus.  

Science.gov (United States)

In a previous study conducted in Cyprus, various spotted fever group Rickettsia species were detected and identified in ticks by molecular analysis. Among them, a partially characterized Rickettsia species was detected in Hyalomma anatolicum excavatum and Rhipicephalus turanicus ticks. We report characterization of this rickettsial strain by using polymerase chain reaction sequencing analysis of partial citrate synthase A, outer membrane protein A, outer membrane protein B, and 17-kD protein genes. We propose a provisional name Rickettsia sp. strain Tselenti for this strain until it is isolated and further characterized. PMID:23438767

Sandalakis, Vassilios; Chochlakis, Dimosthenis; Ioannou, Ioannis; Psaroulaki, Anna

2013-02-25

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Seroprevalencia de Leptospira sp., Rickettsia sp. Ehrlichia sp. en trabajadores rurales del departamento de Sucre, Colombia Seroprevalence of Leptospira sp., Rickettsia sp. and Ehrlichia sp. in rural workers of Sucre, Colombia  

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Full Text Available Objective. Determinar la seroprevalencia de Leptospira sp., Rickettsia sp. y Ehrlichia sp. en trabajadores de áreas rurales del departamento de Sucre. Material y métodos. Se realizó un estudio escriptivo, prospectivo, de corte transversal, que pretendió determinar la seroprevalencia e Leptospira sp., Rickettsia sp. y Ehrlichia sp. en 90 trabajadores de áreas rurales del departamento de Sucre. Se estableció la presencia de anticuerpos séricos anti-IgM específicos anti-Leptospira por la técnica de ELISA indirecta. Para la determinación de Rickettsia sp. y Ehrlichia sp. se uso la técnica de inmunofluorescencia indirecta. Resultados. La población evaluada estaba compuesta por 27 (30%) ordeñadores, 21 (23%) jornaleros, 18 (20%) profesionales del campo y 24 (27%) que realizaban otras actividades. Ventidós (24%) muestras resultaron positivas en alguna de las pruebas. De éstas, 12 (13,3%) fueron positivas para Leptospira sp., 7 (7,8%) para Rickettsia sp. y 3 (3,3%) ara Ehrlichia sp. Conclusión. Este fue el primer estudio que se llevó a cabo en el departamento de Sucre y permitió demostrar que existe una prevalencia importante de Leptospira p.,Rickettsia sp. y Ehrlichia sp.. Los factores de riesgo ocupacional fueron factores determinantes en la seropositividad.Objective. To determine the seroprevalence of Leptospira sp., Rickettsia sp. and Ehrlichia sp. in agricultural workers of Sucre. Methods. A descriptive prospective cross-sectional study was conducted in ninety rural workers of Sucre. Presence of serum antibodies anti-IgM specific anti-Leptospira by indirect ELISA was established. For the determination of Rickettsia and Ehrlichia indirect inmunoflorescence was used. Results.The population was composed by 27 (30%) milkers, 21 (23%) day workers, 18 farm professionals (20%) and 24 (26%) workers in others activities. A total of 22 (24%) samples were positive to some test. Twelve (13.3%) were positive to Leptospira sp., seven (7.8%) to Rickettsia sp. and three (3.3%) o Ehrlichia sp.. Conclusions. This is the first study carried out in Sucre; there is an important prevalence of Leptospira sp., Rickettsia sp. and Ehrlichia sp..The occupational risk factors were decisive in the seropositivity.

Rodrigo Ríos; Sila Franco; Salim Mattar; Mary Urrea; Vaneza Tique

2008-01-01

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Seroprevalencia de Leptospira sp., Rickettsia sp. Ehrlichia sp. en trabajadores rurales del departamento de Sucre, Colombia/ Seroprevalence of Leptospira sp., Rickettsia sp. and Ehrlichia sp. in rural workers of Sucre, Colombia  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Objective. Determinar la seroprevalencia de Leptospira sp., Rickettsia sp. y Ehrlichia sp. en trabajadores de áreas rurales del departamento de Sucre. Material y métodos. Se realizó un estudio escriptivo, prospectivo, de corte transversal, que pretendió determinar la seroprevalencia e Leptospira sp., Rickettsia sp. y Ehrlichia sp. en 90 trabajadores de áreas rurales del departamento de Sucre. Se estableció la presencia de anticuerpos séricos anti-IgM específicos a (more) nti-Leptospira por la técnica de ELISA indirecta. Para la determinación de Rickettsia sp. y Ehrlichia sp. se uso la técnica de inmunofluorescencia indirecta. Resultados. La población evaluada estaba compuesta por 27 (30%) ordeñadores, 21 (23%) jornaleros, 18 (20%) profesionales del campo y 24 (27%) que realizaban otras actividades. Ventidós (24%) muestras resultaron positivas en alguna de las pruebas. De éstas, 12 (13,3%) fueron positivas para Leptospira sp., 7 (7,8%) para Rickettsia sp. y 3 (3,3%) ara Ehrlichia sp. Conclusión. Este fue el primer estudio que se llevó a cabo en el departamento de Sucre y permitió demostrar que existe una prevalencia importante de Leptospira p.,Rickettsia sp. y Ehrlichia sp.. Los factores de riesgo ocupacional fueron factores determinantes en la seropositividad. Abstract in english Objective. To determine the seroprevalence of Leptospira sp., Rickettsia sp. and Ehrlichia sp. in agricultural workers of Sucre. Methods. A descriptive prospective cross-sectional study was conducted in ninety rural workers of Sucre. Presence of serum antibodies anti-IgM specific anti-Leptospira by indirect ELISA was established. For the determination of Rickettsia and Ehrlichia indirect inmunoflorescence was used. Results.The population was composed by 27 (30%) milkers, (more) 21 (23%) day workers, 18 farm professionals (20%) and 24 (26%) workers in others activities. A total of 22 (24%) samples were positive to some test. Twelve (13.3%) were positive to Leptospira sp., seven (7.8%) to Rickettsia sp. and three (3.3%) o Ehrlichia sp.. Conclusions. This is the first study carried out in Sucre; there is an important prevalence of Leptospira sp., Rickettsia sp. and Ehrlichia sp..The occupational risk factors were decisive in the seropositivity.

Ríos, Rodrigo; Franco, Sila; Mattar, Salim; Urrea, Mary; Tique, Vaneza

2008-06-01

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Spotted fever group Rickettsiae in ticks in Cyprus.  

UK PubMed Central (United Kingdom)

In two surveys conducted from March 1999 to March 2001 and from January 2004 to December 2006, a total of 3,950 ticks (belonging to ten different species) were collected from seven domestic and wild animals (goat, sheep, cattle, dog, fox, hare, and mouflon) from different localities throughout Cyprus. In order to establish their infection rate with Spotted Fever Rickettsiae (SFG), ticks were pooled and tested by polymerase chain reaction targeting gltA and ompA genes, followed by sequencing analysis. When tick pools tested positive, individual ticks were then tested one by one, and of the 3,950 ticks screened, rickettsial DNA was identified in 315 ticks (infection rate, 8%). Five SFG Rickettsiae were identified: Rickettsia aeschlimannii in Hyalomma marginatum marginatum, Rickettsia massiliae in Rhipicephalus turanicus and Rhipicephalus sanguineus, Rickettsia sibirica mongolotimonae in Hyalomma anatolicum excavatum, and a Rickettsia endosymbiont of Haemaphysalis sulcata (later described as Rickettsia hoogstraalii) in Haemaphysalis punctata. Two additional genes, 17 kDa and ompB, were targeted to characterize a new genotype of "Candidatus Rickettsia barbariae" genotype in R. turanicus, designated here as "Candidatus Rickettsia barbariae" Cretocypriensis. These results confirm the presence of a spectrum of SFG Rickettsiae on the island. Further studies are necessary to gain better knowledge on the epidemiology of SFG Rickettsiae in Cyprus.

Chochlakis D; Ioannou I; Sandalakis V; Dimitriou T; Kassinis N; Papadopoulos B; Tselentis Y; Psaroulaki A

2012-02-01

 
 
 
 
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Spotted fever group Rickettsiae in ticks in Cyprus.  

Science.gov (United States)

In two surveys conducted from March 1999 to March 2001 and from January 2004 to December 2006, a total of 3,950 ticks (belonging to ten different species) were collected from seven domestic and wild animals (goat, sheep, cattle, dog, fox, hare, and mouflon) from different localities throughout Cyprus. In order to establish their infection rate with Spotted Fever Rickettsiae (SFG), ticks were pooled and tested by polymerase chain reaction targeting gltA and ompA genes, followed by sequencing analysis. When tick pools tested positive, individual ticks were then tested one by one, and of the 3,950 ticks screened, rickettsial DNA was identified in 315 ticks (infection rate, 8%). Five SFG Rickettsiae were identified: Rickettsia aeschlimannii in Hyalomma marginatum marginatum, Rickettsia massiliae in Rhipicephalus turanicus and Rhipicephalus sanguineus, Rickettsia sibirica mongolotimonae in Hyalomma anatolicum excavatum, and a Rickettsia endosymbiont of Haemaphysalis sulcata (later described as Rickettsia hoogstraalii) in Haemaphysalis punctata. Two additional genes, 17 kDa and ompB, were targeted to characterize a new genotype of "Candidatus Rickettsia barbariae" genotype in R. turanicus, designated here as "Candidatus Rickettsia barbariae" Cretocypriensis. These results confirm the presence of a spectrum of SFG Rickettsiae on the island. Further studies are necessary to gain better knowledge on the epidemiology of SFG Rickettsiae in Cyprus. PMID:21833539

Chochlakis, Dimosthenis; Ioannou, Ioannis; Sandalakis, Vassilios; Dimitriou, Theodoros; Kassinis, Nikolaos; Papadopoulos, Byron; Tselentis, Yannis; Psaroulaki, Anna

2011-08-11

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Isolamento de Rickettsia em cultura de células vero  

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Full Text Available Embora o diagnóstico da febre maculosa baseie-se em sinais e sintomas característicos, o mesmo requer confirmação laboratorial, pois existem alguns diagnósticos diferenciais possíveis como meningococcemia, leptospirose, infecção por enterovírus e febre tifóide. A confirmação laboratorial pode ser feita através da pesquisa de anticorpos específicos, possível somente alguns dias após o aparecimento da doença, através do isolamento do agente em amostras de sangue e/ou biópsia de pele, e ainda, de amostras de carrapatos coletados do paciente ou de animais reservatório. O isolamento a partir de sangue ou biópsia de pele resulta em diagnóstico precoce da doença, pois na fase de rickettsemia ainda não há anticorpos detectáveis no sangue. Assim, com o objetivo de facilitar o diagnóstico precoce da febre maculosa, estabelecemos um método de isolamento de rickettsia em cultura de células vero. Para a padronização foi inoculada amostra padrão de Rickettsia rickettsii, cepa Sheyla Smith, cedida pelo CDC. A identificação foi feita através da reação de imunofluorescência indireta. A presença de microrganismos verdes fluorescentes visualizados no interior do citoplasma das células caracterizou o crescimento do agente. Posteriormente, a metodologia foi confirmada pelo isolamento do agente da febre maculosa em amostras de biópsia de pele de paciente proveniente de área endêmica no Estado de São Paulo, bem como, de amostras de carrapato do gênero Amblyomma, considerado o reservatório e transmissor da doença no Brasil.

Melles Heloisa Helena Barbosa; Colombo Silvia; Lemos Elba Regina Sampaio de

1999-01-01

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Citrate synthase gene comparison, a new tool for phylogenetic analysis, and its application for the rickettsiae.  

UK PubMed Central (United Kingdom)

Using PCR and an automated laser fluorescent DNA sequencer, we amplified and sequenced a 1,234-bp fragment of the citrate synthase-encoding gene (gltA) of 28 bacteria belonging to the genus Rickettsia. Comparative sequence analysis showed that most of the spotted fever group (SFG) rickettsiae belonged to one of two subgroups. The first subgroup included Rickettsia massiliae, strain Bar 29, Rickettsia rhipicephali, "Rickettsia aeschlimanni," and Rickettsia montana, which have been isolated only from ticks. The second subgroup was larger and included the majority of the human pathogens and also rickettsiae isolated only from ticks; the members of this subgroup were strain S, Rickettsia africae, "Rickettsia monglotimonae," Rickettsia sibirica, Rickettsia parkeri, Rickettsia conorii, Rickettsia rickettsii, the Thai tick typhus rickettsia, the Israeli tick typhus rickettsia, the Astrakhan fever rickettsia, "Rickettsia slovaca," and Rickettsia japonica. The sequence analysis also showed that the tick-borne organisms Rickettsia helvetica and Rickettsia australis and the mite-borne organism Rickettsia akari were associated with the SFG cluster, that Rickettsia prowazekii and Rickettsia typhi, two representatives of the typhus group, clustered together, and that Rickettsia canada; Rickettsia bellii, and the AB bacterium probably represent three new groups. We compared the phylogenetic trees inferred from citrate synthase gene sequences and from 16S ribosomal DNA (rDNA) sequences. For rickettsial phylogeny, the citrate synthase approach was more suitable, as demonstrated by significant bootstrap values for all of the nodes except those in the larger subgroup defined above. We also compared phylogenetic analysis results obtained in a comparison of the sequences of both genes for all of the representatives of the domain Bacteria for which the gltA sequence was determined. We believe that comparison of gltA sequences could be a complementary approach to 16S rDNA sequencing for inferring bacterial evolution, especially when unstable phylogenetic models are obtained from ribosomal sequences because of high levels of sequence similarity between the bacteria studied.

Roux V; Rydkina E; Eremeeva M; Raoult D

1997-04-01

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Factores predictivos de metástasis Ganglionares axilares, en Cáncer de mama menor de 2 centímetros  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish OBJETIVOS: Demostrar que existen factores clínicopatológicos para predecir metástasis ganglionares axilares en tumores de mama de más o menos 20 mm, de diámetro y también que la disección axilar es un procedimiento innecesario en la mayoría de estas pacientes, que puede omitirse con seguridad en aquellas pacientes con factores pronósticos favorables. MÉTODOS: Se realiza un estudio retrospectivo, revisándose los reportes macroscópicos, microscópicos, e inmunoh (more) istoquímica en los bloques celulares de pacientes con carcinoma mamario de tamaño hasta 20 mm tratadas en el Instituto Oncológico "Dr. Luis Razzeti", entre enero 2000 y diciembre de 2003, determinándose factores que influyen en la aparición de metástasis axilares, realizándose análisis de uni y multivariables. RESULTADOS: El trabajo consistió en una población de 121 pacientes, con una edad media de 57 años, 50 (41,32 %) que presentaron metástasis ganglionar axilar; los factores que se relacionaron con ganglios axilares positivos en el análisis de univariables fueron: grado histológico y nuclear, invasión linfovascular, índice mitótico elevado y tumores aneuploides (P Abstract in english OBJECTIVES: To identify and study that existing pathologically factors and clinical predict nodal metastases axillaries in mammary tumors with diameter size more and minor of 20 mm, so demonstrated in the axillaries dissection is an unnecessary procedure in most of these patients, and can omit with surely in patients with favorable predictive factors. METHODS: We realize a retrospective study, review the macroscopic and microscopic reports, and the inmunohistochemestry in (more) the cellular blocks of patients with breast carcinoma with size until 20 mm treated in the Oncology Institute "Dr. Luis Razetti", between January and December of 2000 - 2003, determining factors that influence in the appearance of lymph nodes axillaries positives, making unvaried and multivariate analysis. RESULTS: These work consisted in the studied of 121 patients with mean age 57 years, 50 (41, 32 %) presented axillaries disease nodes metastases; the factors that were related to positive lymph nodes in the unavailable analysis were: histological and nuclear grade, linfovascular invasion, mitotic index high, aneuploid tumors (P

Godoy Briceño, Alí Josué; Betancourt, Luís; Parada, David; Morales, Sergio Osorio

2007-12-01

65

Factores predictivos de metástasis Ganglionares axilares, en Cáncer de mama menor de 2 centímetros  

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Full Text Available OBJETIVOS: Demostrar que existen factores clínicopatológicos para predecir metástasis ganglionares axilares en tumores de mama de más o menos 20 mm, de diámetro y también que la disección axilar es un procedimiento innecesario en la mayoría de estas pacientes, que puede omitirse con seguridad en aquellas pacientes con factores pronósticos favorables. MÉTODOS: Se realiza un estudio retrospectivo, revisándose los reportes macroscópicos, microscópicos, e inmunohistoquímica en los bloques celulares de pacientes con carcinoma mamario de tamaño hasta 20 mm tratadas en el Instituto Oncológico "Dr. Luis Razzeti", entre enero 2000 y diciembre de 2003, determinándose factores que influyen en la aparición de metástasis axilares, realizándose análisis de uni y multivariables. RESULTADOS: El trabajo consistió en una población de 121 pacientes, con una edad media de 57 años, 50 (41,32 %) que presentaron metástasis ganglionar axilar; los factores que se relacionaron con ganglios axilares positivos en el análisis de univariables fueron: grado histológico y nuclear, invasión linfovascular, índice mitótico elevado y tumores aneuploides (POBJECTIVES: To identify and study that existing pathologically factors and clinical predict nodal metastases axillaries in mammary tumors with diameter size more and minor of 20 mm, so demonstrated in the axillaries dissection is an unnecessary procedure in most of these patients, and can omit with surely in patients with favorable predictive factors. METHODS: We realize a retrospective study, review the macroscopic and microscopic reports, and the inmunohistochemestry in the cellular blocks of patients with breast carcinoma with size until 20 mm treated in the Oncology Institute "Dr. Luis Razetti", between January and December of 2000 - 2003, determining factors that influence in the appearance of lymph nodes axillaries positives, making unvaried and multivariate analysis. RESULTS: These work consisted in the studied of 121 patients with mean age 57 years, 50 (41, 32 %) presented axillaries disease nodes metastases; the factors that were related to positive lymph nodes in the unavailable analysis were: histological and nuclear grade, linfovascular invasion, mitotic index high, aneuploid tumors (P< 0,05). In the multivariate analysis, the linfovascular invasion, mitotic indices elevated and aneuploid tumors were independent factors to predict the axillaries metastases (P< 0,001). CONCLUSIONS: The linfovascular invasion is main predictive factor of axillaries lymph node positive in the breast cancer stratified how T1, these situation and combined with other factors like mitotic indices and tumor ploidy, can indicate to us that patient them the axillaries dissection can be omitted surely to diminish the complications.

Alí Josué Godoy Briceño; Luís Betancourt; David Parada; Sergio Osorio Morales

2007-01-01

66

First report on the occurrence of Rickettsia slovaca and Rickettsia raoultii in Dermacentor silvarum in China  

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Full Text Available Abstract Background Rickettsioses are among both the longest known and most recently recognized infectious diseases. Although new spotted fever group rickettsiae have been isolated in many parts of the world including China, Little is known about the epidemiology of Rickettsia pathogens in ticks from Xinjiang Autonomous Region of China. Methods In an attempt to assess the potential risk of rickettsial infection after exposure to ticks in Xinjiang Uygur Autonomous Region of China, a total of 200 Dermacentor silvarum ticks collected in Xinyuan district were screened by polymerase chain reaction based on the outer membrane protein A gene. Results 22 of the 200 specimens (11%) were found to be positive by PCR. Phylogenetic analysis of OmpA sequences identified two rickettsial species, Rickettsia raoultii (4.5%) and Rickettsia slovaca (6.5%). Conclusions This study has reported the occurrence of Rickettsia raoultii and Rickettsia slovaca in Xinjiang Autonomous Region of China and suggests that Dermacentor silvarum could be involved in the transmission of rickettsial agents in China. Further studies on the characterization and culture of rickettsial species found in Dermacentor silvarum should be performed to further clarify this. Additionally, the screening of human specimens for rickettsial disease in this region will define the incidence of infection.

Tian Zhan-Cheng; Liu Guang-Yuan; Shen Hui; Xie Jun-Ren; Luo Jin; Tian Mei-Yuan

2012-01-01

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Biopsia Ecoguiada De La Axila Y Disección Axilar Mínima Ganglionar, Como Alternativas Para La Identificación De Metástasis En El Ganglio Centinela En Cáncer De Mama  

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Full Text Available OBJETIVOS: Investigar la presencia de metástasis de los ganglios centinela y como alternativa a los métodos tradicionales (Radiofármaco Tc 99 y colorante), MÉTODOS: En 128 pacientes con diagnóstico de cáncer de mama se evaluaron la presencia de ganglios linfáticos axilares. Se utilizó una biopsia ecoguiada de los ganglios de la axila, cuando son vistos al ultrasonido, una disección axilar mínima ganglionar. Se compararon los resultados con la disección axilar estándar. El diagnóstico histológico del tumor primario se realizó por biopsia ecoguiada o por estereotaxia. RESULTADOS: La biopsia ecoguiada de la axila identificó 22 % de metástasis en ganglios centinelas. La disección axilar mínima ganglionar se practicó en el 55 % de las 66 pacientes operadas, fue capaz de identificar ganglios centinelas con metástasis en el 37 %. El ultrasonido es capaz de identificar un 36 % de lesiones subclínicas. La muestra se realizó fundamentalmente en tumores T1 y T2, y cuando la biopsia ecoguiada de la axila identifica metástasis axilares, identifica pacientes de riesgo elevado, independientemente del tamaño de su tumor, que pudieran beneficiarse de un tratamiento de inducción. CONCLUSIONES: El cirujano mastólogo debería utilizar el ultrasonido mamario para la evaluación integral de las pacientes. La biopsia ecoguiada de la axila y la disección axilar mínima ganglionar pudieran ser métodos para la determinación de ganglios centinela, en forma más accesible a hospitales públicos, evitando la morbilidad de la disección axilar completa en tumores pequeños con ganglios negativos.OBJECTIVES: o investigate the presence of metastasis of the sentinel node and like alternative to the traditional methods (Radio pharmacy Tc 99 and colorant), METHODS: In 128 patients with diagnosis of breast cancer, we evaluated the presence of axillary lymphatic nodes. We used an ecoguide biopsy of the axillary lymphatic nodes, when they are seen by ultrasound, a minimal axillary nodes dissection. The results were compared with the standard axillary dissection. The histological diagnose of the primary tumor was made by ecoguide biopsy or estereotaxia biopsy. RESULTS: The axillary lymphatic nodes ecoguide biopsy identified 22 % of metastasic sentinel nodes. The minimal axillary nodes dissection was practiced in 55 % of the 66 operated patients, and was able to identify the metastasic sentinel nodes in 37 % patients. The ultrasound was able to identify subclinical lesions in 36 % of the cases. The biopsy samples was performed fundamentally in T1 and T2 tumors; when the ecoguide biopsy of axillary nodes identifies axillary metastasis, it identifies high risk patients, independently as large as its tumor, than they could benefit from an induction treatment. CONCLUSIONS: The breast surgeon would have to use the breast ultrasound for an integral evaluation of the patients. The ecoguide biopsy of the axillary lymphatic nodes and the minimal axillary nodes dissection could be methods for the determination of sentinel nodes, in more accessible way to public hospitals, avoiding the morbidity of a complete axillary dissection of the in small tumors.

JORGE URIBE; MARÍA EUGENIA MÁRQUEZ; NAYSA BOSCÁsN; FRANCISCO MENOLASCINO; JORGE LUIS URIBE A

2006-01-01

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Rickettsia felis–associated Uneruptive Fever, Senegal  

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During November 2008–July 2009, we investigated the origin of unknown fever in Senegalese patients with a negative malaria test result, focusing on potential rickettsial infection. Using molecular tools, we found evidence for Rickettsia felis–associated illness in the initial days of infection in fe...

Socolovschi, Cristina; Mediannikov, Oleg; Sokhna, Cheikh; Tall, Adama; Diatta, Georges; Bassene, Hubert; Trape, Jean-François

69

Rickettsia felis-associated uneruptive fever, Senegal.  

Science.gov (United States)

During November 2008-July 2009, we investigated the origin of unknown fever in Senegalese patients with a negative malaria test result, focusing on potential rickettsial infection. Using molecular tools, we found evidence for Rickettsia felis-associated illness in the initial days of infection in febrile Senegalese patients without malaria. PMID:20587190

Socolovschi, Cristina; Mediannikov, Oleg; Sokhna, Cheikh; Tall, Adama; Diatta, Georges; Bassene, Hubert; Trape, Jean François; Raoult, Didier

2010-07-01

70

Rickettsia felis-associated uneruptive fever, Senegal.  

UK PubMed Central (United Kingdom)

During November 2008-July 2009, we investigated the origin of unknown fever in Senegalese patients with a negative malaria test result, focusing on potential rickettsial infection. Using molecular tools, we found evidence for Rickettsia felis-associated illness in the initial days of infection in febrile Senegalese patients without malaria.

Socolovschi C; Mediannikov O; Sokhna C; Tall A; Diatta G; Bassene H; Trape JF; Raoult D

2010-07-01

71

Rickettsia slovaca Infection in Humans, Portugal.  

Science.gov (United States)

Fifteen years after the initial detection of Rickettsia slovaca in ticks in Portugal, 3 autochthonous cases of R. slovaca infection were diagnosed in humans. All patients had an eschar on the scalp and lymphadenopathy; 2 patients had facial edema. R. slovaca infection was confirmed by serologic testing, culture, and PCR. PMID:24050379

de Sousa, Rita; Pereira, Branca Isabel; Nazareth, Claúdia; Cabral, Susana; Ventura, Conceição; Crespo, Pedro; Marques, Nuno; da Cunha, Saraiva

2013-10-01

72

Rickettsia slovaca Infection in Humans, Portugal.  

UK PubMed Central (United Kingdom)

Fifteen years after the initial detection of Rickettsia slovaca in ticks in Portugal, 3 autochthonous cases of R. slovaca infection were diagnosed in humans. All patients had an eschar on the scalp and lymphadenopathy; 2 patients had facial edema. R. slovaca infection was confirmed by serologic testing, culture, and PCR.

de Sousa R; Pereira BI; Nazareth C; Cabral S; Ventura C; Crespo P; Marques N; da Cunha S

2013-10-01

73

Rickettsia rickettsii in Rhipicephalus ticks, Mexicali, Mexico.  

UK PubMed Central (United Kingdom)

Circulation of a unique genetic type of Rickettsia rickettsii in ticks of the Rhipicephalus sanguineus complex was detected in Mexicali, Baja California, Mexico. The Mexican R. rickettsii differed from all isolates previously characterized from the endemic regions of Rocky Mountain spotted fever in northern, central, and southern Americas. Rhipicephalus ticks in Mexicali are genetically different from Rh. sanguineus found in the United States.

Eremeeva ME; Zambrano ML; Anaya L; Beati L; Karpathy SE; Santos-Silva MM; Salceda B; MacBeth D; Olguin H; Dasch GA; Aranda CA

2011-03-01

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Rickettsia felis in Fleas, Western Australia  

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This study is the first confirmation of Rickettsia felis in Australia. The organism was identified from 4 species of fleas obtained from dogs and cats in Western Australia, by using polymerase chain reaction amplification and DNA sequencing of the citrate synthase and outer membrane protein A genes.

Schloderer, Drew; Owen, Helen; Clark, Phillip; Stenos, John; Fenwick, Stanley G.

75

Bartonella quintana and Rickettsia felis in Gabon  

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We detected Rickettsia felis DNA in Ctenocephalides felis and Bartonella quintana DNA in 3 Pulex irritans fleas taken from a pet Cercopithecus cephus monkey in Gabon, sub-Saharan Africa. This is the first report of B. quintana in the human flea.

Rolain, Jean-Marc; Bourry, Olivier; Davoust, Bernard; Raoult, Didier

76

Rickettsia species in African Anopheles mosquitoes.  

UK PubMed Central (United Kingdom)

BACKGROUND: There is higher rate of R. felis infection among febrile patients than in healthy people in Sub-Saharan Africa, predominantly in the rainy season. Mosquitoes possess a high vectorial capacity and, because of their abundance and aggressiveness, likely play a role in rickettsial epidemiology. METHODOLOGY/PRINCIPAL FINDINGS: Quantitative and traditional PCR assays specific for Rickettsia genes detected rickettsial DNA in 13 of 848 (1.5%) Anopheles mosquitoes collected from Côte d'Ivoire, Gabon, and Senegal. R. felis was detected in one An. gambiae molecular form S mosquito collected from Kahin, Côte d'Ivoire (1/77, 1.3%). Additionally, a new Rickettsia genotype was detected in five An. gambiae molecular form S mosquitoes collected from Côte d'Ivoire (5/77, 6.5%) and one mosquito from Libreville, Gabon (1/88, 1.1%), as well as six An. melas (6/67, 9%) mosquitoes collected from Port Gentil, Gabon. A sequence analysis of the gltA, ompB, ompA and sca4 genes indicated that this new Rickettsia sp. is closely related to R. felis. No rickettsial DNA was detected from An. funestus, An. arabiensis, or An. gambiae molecular form M mosquitoes. Additionally, a BLAST analysis of the gltA sequence from the new Rickettsia sp. resulted in a 99.71% sequence similarity to a species (JQ674485) previously detected in a blood sample of a Senegalese patient with a fever from the Bandafassi village, Kedougou region. CONCLUSION: R. felis was detected for the first time in An. gambiae molecular form S, which represents the major African malaria vector. The discovery of R. felis, as well as a new Rickettsia species, in mosquitoes raises new issues with respect to African rickettsial epidemiology that need to be investigated, such as bacterial isolation, the degree of the vectorial capacity of mosquitoes, the animal reservoirs, and human pathogenicity.

Socolovschi C; Pages F; Ndiath MO; Ratmanov P; Raoult D

2012-01-01

77

Seroepidemiologic survey of Orientia tsutsugamushi, Rickettsia typhi, and TT118 spotted fever group rickettsiae in rubber estate workers in Malaysia.  

UK PubMed Central (United Kingdom)

The seroprevalence of Orientia tsutsugamushi, Rickettsia typhi, and TT118 spotted fever group (SFG) rickettsiae in 300 rubber estate workers in Slim River, Malaysia was determined in December 1996 and March 1997. In December, which was the wet season, 23.3%, 3.0%, and 57.3% of the population had antibodies detected against the three rickettsiae, respectively. The highest seropositive rate of 40% was detected for single infection with SFG rickettsiae, followed by a rate of 15.3% for both O. tsutsugamushi and SFG rickettsiae among the rubber estate workers. Subjects less than 21 years old had a lower seroprevalence of SFG rickettsiae compared with the other age groups. Indians had a higher seroprevalence of O. tsutsugamushi compared with other ethnic groups. Rubber tappers had a higher seroprevalence of SFG rickettsiae compared with other occupational groups. During the dry season in March 1997, there was a significant increase in the seroprevalence of R. typhi. The seroconversion rates for IgM against O. tsutsugamushi, R. typhi, and SFG rickettsiae were 5.7%, 12.3%, and 15.1%, respectively, during the four-month period. Significant variations of antibody titers towards the three rickettsiae was noted among subjects who were bled twice. This suggests a significant and continual exposure of rubber estate workers to the three rickettsiae.

Tee TS; Kamalanathan M; Suan KA; Chun SS; Ming HT; Yasin RM; Devi S

1999-07-01

78

Seroepidemiologic survey of Orientia tsutsugamushi, Rickettsia typhi, and TT118 spotted fever group rickettsiae in rubber estate workers in Malaysia.  

Science.gov (United States)

The seroprevalence of Orientia tsutsugamushi, Rickettsia typhi, and TT118 spotted fever group (SFG) rickettsiae in 300 rubber estate workers in Slim River, Malaysia was determined in December 1996 and March 1997. In December, which was the wet season, 23.3%, 3.0%, and 57.3% of the population had antibodies detected against the three rickettsiae, respectively. The highest seropositive rate of 40% was detected for single infection with SFG rickettsiae, followed by a rate of 15.3% for both O. tsutsugamushi and SFG rickettsiae among the rubber estate workers. Subjects less than 21 years old had a lower seroprevalence of SFG rickettsiae compared with the other age groups. Indians had a higher seroprevalence of O. tsutsugamushi compared with other ethnic groups. Rubber tappers had a higher seroprevalence of SFG rickettsiae compared with other occupational groups. During the dry season in March 1997, there was a significant increase in the seroprevalence of R. typhi. The seroconversion rates for IgM against O. tsutsugamushi, R. typhi, and SFG rickettsiae were 5.7%, 12.3%, and 15.1%, respectively, during the four-month period. Significant variations of antibody titers towards the three rickettsiae was noted among subjects who were bled twice. This suggests a significant and continual exposure of rubber estate workers to the three rickettsiae. PMID:10432060

Tee, T S; Kamalanathan, M; Suan, K A; Chun, S S; Ming, H T; Yasin, R M; Devi, S

1999-07-01

79

Molecular detection of Rickettsia felis and Candidatus Rickettsia Asemboensis in Fleas from Human Habitats, Asembo, Kenya.  

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Abstract The flea-borne rickettsioses murine typhus (Rickettsia typhi) and flea-borne spotted fever (FBSF) (Rickettsia felis) are febrile diseases distributed among humans worldwide. Murine typhus has been known to be endemic to Kenya since the 1950s, but FBSF was only recently documented in northeastern (2010) and western (2012) Kenya. To characterize the potential exposure of humans in Kenya to flea-borne rickettsioses, a total of 330 fleas (134 pools) including 5 species (Xenopsylla cheopis, Ctenocephalides felis, Ctenocephalides canis, Pulex irritans, and Echidnophaga gallinacea) were collected from domestic and peridomestic animals and from human dwellings within Asembo, western Kenya. DNA was extracted from the 134 pooled flea samples and 89 (66.4%) pools tested positively for rickettsial DNA by 2 genus-specific quantitative real-time PCR (qPCR) assays based upon the citrate synthase (gltA) and 17-kD antigen genes and the Rfelis qPCR assay. Sequences from the 17-kD antigen gene, the outer membrane protein (omp)B, and 2 R. felis plasmid genes (pRF and pRFd) of 12 selected rickettsia-positive samples revealed a unique Rickettsia sp. (n=11) and R. felis (n=1). Depiction of the new rickettsia by multilocus sequence typing (MLST) targeting the 16S rRNA (rrs), 17-kD antigen gene, gltA, ompA, ompB, and surface cell antigen 4 (sca4), shows that it is most closely related to R. felis but genetically dissimilar enough to be considered a separate species provisionally named Candidatus Rickettsia asemboensis. Subsequently, 81 of the 134 (60.4%) flea pools tested positively for Candidatus Rickettsia asemboensis by a newly developed agent-specific qPCR assay, Rasemb. R. felis was identified in 9 of the 134 (6.7%) flea pools, and R. typhi the causative agent of murine typhus was not detected in any of 78 rickettsia-positive pools assessed using a species-specific qPCR assay, Rtyph. Two pools were found to contain both R. felis and Candidatus Rickettsia asemboensis DNA and 1 pool contained an agent, which is potentially new. PMID:23675818

Jiang, Ju; Maina, Alice N; Knobel, Darryn L; Cleaveland, Sarah; Laudisoit, Anne; Wamburu, Kabura; Ogola, Eric; Parola, Philippe; Breiman, Robert F; Njenga, M Kariuki; Richards, Allen L

2013-05-15

80

Molecular detection of rickettsia felis and candidatus rickettsia asemboensis in fleas from human habitats, Asembo, Kenya.  

UK PubMed Central (United Kingdom)

The flea-borne rickettsioses murine typhus (Rickettsia typhi) and flea-borne spotted fever (FBSF) (Rickettsia felis) are febrile diseases distributed among humans worldwide. Murine typhus has been known to be endemic to Kenya since the 1950s, but FBSF was only recently documented in northeastern (2010) and western (2012) Kenya. To characterize the potential exposure of humans in Kenya to flea-borne rickettsioses, a total of 330 fleas (134 pools) including 5 species (Xenopsylla cheopis, Ctenocephalides felis, Ctenocephalides canis, Pulex irritans, and Echidnophaga gallinacea) were collected from domestic and peridomestic animals and from human dwellings within Asembo, western Kenya. DNA was extracted from the 134 pooled flea samples and 89 (66.4%) pools tested positively for rickettsial DNA by 2 genus-specific quantitative real-time PCR (qPCR) assays based upon the citrate synthase (gltA) and 17-kD antigen genes and the Rfelis qPCR assay. Sequences from the 17-kD antigen gene, the outer membrane protein (omp)B, and 2 R. felis plasmid genes (pRF and pRFd) of 12 selected rickettsia-positive samples revealed a unique Rickettsia sp. (n=11) and R. felis (n=1). Depiction of the new rickettsia by multilocus sequence typing (MLST) targeting the 16S rRNA (rrs), 17-kD antigen gene, gltA, ompA, ompB, and surface cell antigen 4 (sca4), shows that it is most closely related to R. felis but genetically dissimilar enough to be considered a separate species provisionally named Candidatus Rickettsia asemboensis. Subsequently, 81 of the 134 (60.4%) flea pools tested positively for Candidatus Rickettsia asemboensis by a newly developed agent-specific qPCR assay, Rasemb. R. felis was identified in 9 of the 134 (6.7%) flea pools, and R. typhi the causative agent of murine typhus was not detected in any of 78 rickettsia-positive pools assessed using a species-specific qPCR assay, Rtyph. Two pools were found to contain both R. felis and Candidatus Rickettsia asemboensis DNA and 1 pool contained an agent, which is potentially new.

Jiang J; Maina AN; Knobel DL; Cleaveland S; Laudisoit A; Wamburu K; Ogola E; Parola P; Breiman RF; Njenga MK; Richards AL

2013-08-01

 
 
 
 
81

Restriction fragment length polymorphism of the DNA of typhus group rickettsiae.  

UK PubMed Central (United Kingdom)

The DNA of 10 strains of Rickettsia prowazekii, 5 strains of Rickettsia typhi and 1 strain of Rickettsia canada was investigated by restriction fragment length polymorphism analysis. Interspecies differences were characterized by a great number of noncomigrating bands. Using the endonuclease HindIII and PstI fragments comigration as a quantitative criterion, genetic similarity coefficient was calculated for the pair Rickettsia prowazekii/Rickettsia typhi-32.0%, for Rickettsia prowazekii/Rickettsia canada-22.7%, and for Rickettsia typhi/Rickettsia canada-23.5%. Intraspecies differences expressed are very subtle and concern 1-2 noncomigrating fragments. The investigated strains of Rickettsia prowazekii and Rickettsia typhi can be divided into 2 groups without any correlation to the source and period of isolation, or to strain passage history.

Artemiev MI; Ignatovich VF; Rydkina EB; Lichoded LJ; Balayeva NM; Demkin VV

1991-11-01

82

Restriction fragment length polymorphism of the DNA of typhus group rickettsiae.  

Science.gov (United States)

The DNA of 10 strains of Rickettsia prowazekii, 5 strains of Rickettsia typhi and 1 strain of Rickettsia canada was investigated by restriction fragment length polymorphism analysis. Interspecies differences were characterized by a great number of noncomigrating bands. Using the endonuclease HindIII and PstI fragments comigration as a quantitative criterion, genetic similarity coefficient was calculated for the pair Rickettsia prowazekii/Rickettsia typhi-32.0%, for Rickettsia prowazekii/Rickettsia canada-22.7%, and for Rickettsia typhi/Rickettsia canada-23.5%. Intraspecies differences expressed are very subtle and concern 1-2 noncomigrating fragments. The investigated strains of Rickettsia prowazekii and Rickettsia typhi can be divided into 2 groups without any correlation to the source and period of isolation, or to strain passage history. PMID:1687635

Artemiev, M I; Ignatovich, V F; Rydkina, E B; Lichoded, L J; Balayeva, N M; Demkin, V V

1991-11-01

83

Detection of "Rickettsia sp. strain Uilenbergi" and "Rickettsia sp. strain Davousti" in Amblyomma tholloni ticks from elephants in Africa  

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Full Text Available Abstract Background To date, 6 tick-borne rickettsiae pathogenic for humans are known to occur in Africa and 4 of them were first identified in ticks before being recognized as human pathogens. Results We examined 33 and 5 Amblyomma tholloni ticks from African elephants in the Central African Republic and Gabon, respectively, by PCR amplification and sequencing of a part of gltA and ompA genes of the genus Rickettsia. The partial sequences of gltA and ompA genes detected in tick in Gabon had 99.1% similarity with those of R. heilongjiangensis and 97.1% with those of Rickettsia sp. HL-93 strain, respectively. The partial gltA and ompA gene sequences detected in tick in the Central African Republic were 98.9% and 95.1% similar to those of Rickettsia sp. DnS14 strain and R. massiliae, respectively. Phylogenetic analysis showed Rickettsia sp. detected in Gabon clusters with R. japonica and R. heilongjiangensis in a phylogenetic tree based on the partial gltA and ompA genes. The genotype of the Rickettsia sp. detected in the Central African Republic is close to those of R. massiliae group in the phylogenetic tree based on partial gltA gene sequences, and distantly related to other rickettsiae in the tree based on partial ompA gene. Conclusion The degrees of similarity of partial gltA and ompA genes with recognized species indicate the rickettsiae detected in this study may be new species although we could only study the partial sequences of 2 genes regarding the amount of DNA that was available. We propose the Rickettsia sp. detected in Gabon be provisionally named "Rickettsia sp. stain Davousti" and Rickettsia sp. detected in the Central African Republic be named "Rickettsia sp. strain Uilenbergi".

Matsumoto Kotaro; Parola Philippe; Rolain Jean-Marc; Jeffery Kathryn; Raoult Didier

2007-01-01

84

Metástasis ganglionar tardía de carcinoma de células renales: Aportación de un caso/ Late lymoh node metastasis in renal cell carcinoma: Case report  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Objetivo: Presentar un caso de metástasis tardía por carcinoma de células renales tratado con cirugía radical. Método/Resultados: Paciente intervenido de nefrectomía radical y linfadenectomía por tumor renal que 6 años después de la cirugía, en un control rutinario presentó metástasis a nivel ganglionar regional. Tras tratamiento con inmunoterapia, que se suspendió por intolerancia, se decidió cirugía de la masa adenopática metastásica. Conclusión: El c? (more) ?ncer renal constituye un tumor imprevisible en cuanto a su comportamiento, de manera que puede metastatizar en cualquier momento de su evolución, incluso tras cirugía radical y tras varios años libres de enfermedad. La cirugía de las metástasis del cáncer renal constituyen una opción terapéutica con buenos resultados a largo plazo, cuando éstas son únicas y accesibles a la cirugía. Abstract in english Objective: To report one case of late metastasis of a clear cell carcinoma treated by radical surgery. Methods/Results: Patient with history of radical nephrectomy and lymphadenectomy six years before presenting with regional lymph node metastasis in a follow-up diagnostic test. After treatment with immunotherapy, stopped because of intolerance, surgery of the metastatic lymph node mass was decided. Conclusions: Renal cancer is an unpredictable tumor in terms of oncologic (more) al behaviour, so that it may metastasize any time in its evolution, even after radical surgery and several years free of disease. Surgery for the metastases of renal cancer is a good therapeutic option, with good long-term results, when they are isolated and accessible to surgery.

Giménez Bachs, José Miguel; Lorenzo Romero, Juan Gabriel; Pastor Guzmán, José María; Donate Moreno, María José; Pastor Navarro, Héctor; Carrión López, Pedro; Salinas Sánchez, Antonio Santiago; Virseda Rodríguez, Julio Antonio

2007-06-01

85

Permeability of Rickettsia prowazekii to NAD  

International Nuclear Information System (INIS)

Rickettsia prowazekii accumulated radioactivity from [adenine-2,8-3H]NAD but not from [nicotinamide-4-3H]NAD, which demonstrated that NAD was not taken up intact. Extracellular NAD was hydrolyzed by rickettsiae with the products of hydrolysis, nicotinamide mononucleotide and AMP, appearing in the incubation medium in a time- and temperature-dependent manner. The particulate (membrane) fraction contained 90% of this NAD pyrophosphatase activity. Rickettsiae which had accumulated radiolabel after incubation with [adenine-2,8-3H]NAD were extracted, and the intracellular composition was analyzed by chromatography. The cells contained labeled AMP, ADP, ATP, and NAD. The NAD-derived intracellular AMP was transported via a pathway distinct from and in addition to the previously described AMP translocase. Exogenous AMP (1 mM) inhibited uptake of radioactivity from [adenine-2,8-3H]NAD and hydrolysis of extracellular NAD. AMP increased the percentage of intracellular radiolabel present as NAD. Nicotinamide mononucleotide was not taken up by the rickettsiae, did not inhibit hydrolysis of extracellular NAD, and was not a good inhibitor of the uptake of radiolabel from [adenine-2,8-3H]NAD. Neither AMP nor ATP (both of which are transported) could support the synthesis of intracellular NAD. The presence of intracellular [adenine-2,8-3H]NAD within an organism in which intact NAD could not be transported suggested the resynthesis from AMP of [adenine-2,8-3H]NAD at the locus of NAD hydrolysis and translocation.

1989-01-01

86

Rickettsia amblyommii infecting Amblyomma americanum larvae.  

UK PubMed Central (United Kingdom)

Polymerase chain reaction analysis of Amblyomma americanum adults, nymphs, and larvae from Aberdeen Proving Ground, MD (APG), revealed a very high prevalence of a spotted fever group (SFG) rickettsia. Restriction fragment length polymorphism (RFLP) and sequence analysis identified "Rickettsia amblyommii." This organism is not yet described or well studied, and its pathogenicity is unknown; however, investigations of the organism are warranted because of its high prevalence in A. americanum. This tick is extremely abundant at military training facilities in the south, central, and Mid-Atlantic United States, and many soldiers experience multiple concurrent tick bites. Bites by R. amblyommii-infected A. americanum may account for rates of SFG rickettsia seropositivity that are higher than reported rates of Rocky Mountain spotted fever (RMSF) cases from the same location. Seroconversion to SFG rickettsia following bites of A. americanum may suggest that R. amblyommii is infectious in humans. Subclinical infection in the numerous A. americanum tick bite victims could contaminate donated blood and compromise immunodeficient recipients. Detection of R. amblyommii in questing A. americanum larvae suggests transovarial transmission. The absence of R. rickettsii, the agent of RMSF, in A. americanum may be due to transovarial interference by R. amblyommii. The likelihood of pathogen transmission by larvae is magnified by their habit of mass attack. The very small size of the larvae is also a risk factor for pathogen transmission. High R. amblyommii prevalence in populations of A. americanum presage co-infection with other A. americanum-borne pathogens. A. americanum nymphs and adults from APG were found to be co-infected with R. amblyommii and Borrelia lonestari, Ehrlichia chaffeensis and Ehrlichia ewingii, respectively, and larval pools were infected with both R. amblyommii and B. lonestari. Co-infections can compound effects and complicate diagnosis of tick-borne disease.

Stromdahl EY; Vince MA; Billingsley PM; Dobbs NA; Williamson PC

2008-01-01

87

High seroprevalence for typhus group rickettsiae, southwestern Tanzania.  

UK PubMed Central (United Kingdom)

Rickettsioses caused by typhus group rickettsiae have been reported in various African regions. We conducted a cross-sectional survey of 1,227 participants from 9 different sites in the Mbeya region, Tanzania; overall seroprevalence of typhus group rickettsiae was 9.3%. Risk factors identified in multivariable analysis included low vegetation density and highway proximity.

Dill T; Dobler G; Saathoff E; Clowes P; Kroidl I; Ntinginya E; Machibya H; Maboko L; Löscher T; Hoelscher M; Heinrich N

2013-02-01

88

Detecting Rickettsia parkeri infection from eschar swab specimens.  

UK PubMed Central (United Kingdom)

The typical clinical presentation of several spotted fever group Rickettsia infections includes eschars. Clinical diagnosis of the condition is usually made by analysis of blood samples. We describe a more sensitive, noninvasive means of obtaining a sample for diagnosis by using an eschar swab specimen from patients infected with Rickettsia parkeri.

Myers T; Lalani T; Dent M; Jiang J; Daly PL; Maguire JD; Richards AL

2013-05-01

89

Detecting Rickettsia parkeri Infection from Eschar Swab Specimens  

Science.gov (United States)

The typical clinical presentation of several spotted fever group Rickettsia infections includes eschars. Clinical diagnosis of the condition is usually made by analysis of blood samples. We describe a more sensitive, noninvasive means of obtaining a sample for diagnosis by using an eschar swab specimen from patients infected with Rickettsia parkeri.

Lalani, Tahaniyat; Dent, Mike; Jiang, Ju; Daly, Patrick L.; Maguire, Jason D.; Richards, Allen L.

2013-01-01

90

Detecting Rickettsia parkeri infection from eschar swab specimens.  

Science.gov (United States)

The typical clinical presentation of several spotted fever group Rickettsia infections includes eschars. Clinical diagnosis of the condition is usually made by analysis of blood samples. We describe a more sensitive, noninvasive means of obtaining a sample for diagnosis by using an eschar swab specimen from patients infected with Rickettsia parkeri. PMID:23647926

Myers, Todd; Lalani, Tahaniyat; Dent, Mike; Jiang, Ju; Daly, Patrick L; Maguire, Jason D; Richards, Allen L

2013-05-01

91

Exotic Rickettsiae in Ixodes ricinus: fact or artifact?  

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Full Text Available Abstract Several pathogenic Rickettsia species can be transmitted via Ixodes ricinus ticks to humans and animals. Surveys of I. ricinus for the presence of Rickettsiae using part of its 16S rRNA gene yield a plethora of new and different Rickettsia sequences. Interpreting these data is sometimes difficult and presenting these findings as new or potentially pathogenic Rickettsiae should be done with caution: a recent report suggested presence of a known human pathogen, R. australis, in questing I. ricinus ticks in Europe. A refined analysis of these results revealed that R. helvetica was most likely to be misinterpreted as R. australis. Evidence in the literature is accumulating that rickettsial DNA sequences found in tick lysates can also be derived from other sources than viable, pathogenic Rickettsiae. For example, from endosymbionts, environmental contamination or even horizontal gene transfer.

Tijsse-Klasen Ellen; Fonville Manoj; van Overbeek Leo; Reimerink Johan HJ; Sprong Hein

2010-01-01

92

First direct detection of rickettsial pathogens and a new rickettsia, 'Candidatus Rickettsia barbariae', in ticks from Sardinia, Italy.  

Science.gov (United States)

The present study evaluated the molecular detection and identification of Rickettsia species in 83 ticks collected in Sardinia, Italy. Fifteen ticks were PCR-positive using gltA-specific and ompA-specific primers, leading to the identification of Rickettsia aeschlimannii in Hyalomma marginatum marginatum, R. massiliae in Rhipicephalus turanicus and in Rhipicephalus sanguineus, and a new rickettsia, previously referred to as PoTiRb169 in Portugal, in four Rhipicephalus turanicus. This new species was further characterized by amplification and sequencing of three additional genes (ompB, sca4 and rrs). Using the current criteria to name a rickettsia, this uncultivated rickettsia can be given a Candidatus status, and we propose to call it 'Candidatus Rickettsia barbariae'. The detection of three tick-borne rickettsiae in Sardinia raises the possibility that many cases of spotted fever considered by clinicians and health authorities as Mediterranean spotted fever due to R. conorii could, in fact, be due to other rickettsiae, including those found in this study. Analysing skin biopsies of inoculation eschars in patients with spotted fever would be, together with continuing entomological surveys, the best way to increase our knowledge of tick-borne rickettsioses in Sardinia and more generally in the Mediterranean basin. PMID:19040474

Mura, A; Masala, G; Tola, S; Satta, G; Fois, F; Piras, P; Rolain, J-M; Raoult, D; Parola, P

2008-11-01

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Actualización en metástasis ganglionar de carcinoma escamoso de cabeza y cuello: Disección ganglionar, ganglio centinela y técnicas de biología molecular/ Update in lymph node metastasis from head and neck squamous cell carcinoma: Lymph node dissection, sentinel lymph node and molecular biology techniques  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El carcinoma escamoso es la principal neoplasia maligna de cabeza y cuello en los adultos. Esta neoplasia se origina en la mucosa del tracto aerodigestivo superior. Se discute su extensión en superficie y las metástasis a ganglios linfáticos cervicales. El compromiso ganglionar es el principal factor pronóstico independiente del carcinoma escamoso de cabeza y cuello, pues la presencia de adenopatías metastásicas reduce la sobrevida casi en 50%. La siguiente revisió (more) n se centra en tres temas relacionados con las metástasis ganglionares en carcinoma escamoso de cabeza y cuello (CECC): la clasificación de niveles ganglionares y de la disección ganglionar cervical, la técnica del ganglio centinela en el CECC y las técnicas de biología molecular para el diagnóstico del compromiso tumoral ganglionar Abstract in english Squamous cell carcinoma is the main head and neck malignant cancer in adults. This cancer originates from the upper aero digestive tract mucosa. Its surface extension and cervical lymph node metastases are discussed. Lymph node involvement is the main independent prognostic factor in head and neck squamous cell carcinoma, given that the presence of metastatic nodes reduce survival by approximately 50%. The present review focus on three topics related to lymph nodes metast (more) asis of head and neck squamous cell carcinomas (CECC): Classification of lymph node levels and cervical node dissection, the sentinel lymph node technique in CECC, and the use of molecular biology techniques for diagnosing lymph node involvement

Ortega R, Pablo

2008-04-01

94

Rickettsia slovaca from Dermacentor marginatus ticks in Sardinia, Italy.  

UK PubMed Central (United Kingdom)

Nineteen ticks belonging to the species Dermacentor marginatus, Rhipicephalus bursa, and Haemaphysalis sulcata were collected from wild animals (wild boar, deer, and mouflon) in south-western Sardinia, Italy. Five D. marginatus ticks from wild boar were PCR-positive when analyzed using gltA-specific and ompA-specific primers, leading to the identification and first isolation in cell culture of Rickettsia slovaca, the causative agent of tick-borne lymphadenopathy (TIBOLA), on the island of Sardinia. This study confirms the detection of a new tick-borne rickettsia that can be added to the others already known to be present in Sardinia (Rickettsia aeschlimannii, R. massiliae, and Candidatus Rickettsia barbariae). These data increase our knowledge of tick-borne rickettsioses in Sardinia and, more generally, in the Mediterranean basin.

Masala G; Chisu V; Satta G; Socolovschi C; Raoult D; Parola P

2012-12-01

95

Rickettsia slovaca from Dermacentor marginatus ticks in Sardinia, Italy.  

Science.gov (United States)

Nineteen ticks belonging to the species Dermacentor marginatus, Rhipicephalus bursa, and Haemaphysalis sulcata were collected from wild animals (wild boar, deer, and mouflon) in south-western Sardinia, Italy. Five D. marginatus ticks from wild boar were PCR-positive when analyzed using gltA-specific and ompA-specific primers, leading to the identification and first isolation in cell culture of Rickettsia slovaca, the causative agent of tick-borne lymphadenopathy (TIBOLA), on the island of Sardinia. This study confirms the detection of a new tick-borne rickettsia that can be added to the others already known to be present in Sardinia (Rickettsia aeschlimannii, R. massiliae, and Candidatus Rickettsia barbariae). These data increase our knowledge of tick-borne rickettsioses in Sardinia and, more generally, in the Mediterranean basin. PMID:23140897

Masala, Giovanna; Chisu, Valentina; Satta, Giuseppe; Socolovschi, Christina; Raoult, Didier; Parola, Philippe

2012-10-22

96

Rickettsia felis in Ctenocephalides felis from Guatemala and Costa Rica.  

UK PubMed Central (United Kingdom)

Rickettsia felis is an emerging human pathogen associated primarily with the cat flea Ctenocephalides felis. In this study, we investigated the presence of Rickettsia felis in C. felis from Guatemala and Costa Rica. Ctenocephalides felis were collected directly from dogs and cats, and analyzed by polymerase chain reaction for Rickettsia-specific fragments of 17-kDa protein, OmpA, and citrate synthase genes. Rickettsia DNA was detected in 64% (55 of 86) and 58% (47 of 81) of flea pools in Guatemala and Costa Rica, respectively. Sequencing of gltA fragments identified R. felis genotype URRWXCal(2) in samples from both countries, and genotype Rf2125 in Costa Rica. This is the first report of R. felis in Guatemala and of genotype Rf2125 in Costa Rica. The extensive presence of this pathogen in countries of Central America stresses the need for increased awareness and diagnosis.

Troyo A; Álvarez D; Taylor L; Abdalla G; Calderón-Arguedas Ó; Zambrano ML; Dasch GA; Lindblade K; Hun L; Eremeeva ME; Estévez A

2012-06-01

97

Rickettsia felis in Ctenocephalides felis from Guatemala and Costa Rica  

Science.gov (United States)

Rickettsia felis is an emerging human pathogen associated primarily with the cat flea Ctenocephalides felis. In this study, we investigated the presence of Rickettsia felis in C. felis from Guatemala and Costa Rica. Ctenocephalides felis were collected directly from dogs and cats, and analyzed by polymerase chain reaction for Rickettsia-specific fragments of 17-kDa protein, OmpA, and citrate synthase genes. Rickettsia DNA was detected in 64% (55 of 86) and 58% (47 of 81) of flea pools in Guatemala and Costa Rica, respectively. Sequencing of gltA fragments identified R. felis genotype URRWXCal2 in samples from both countries, and genotype Rf2125 in Costa Rica. This is the first report of R. felis in Guatemala and of genotype Rf2125 in Costa Rica. The extensive presence of this pathogen in countries of Central America stresses the need for increased awareness and diagnosis.

Troyo, Adriana; Alvarez, Danilo; Taylor, Lizeth; Abdalla, Gabriela; Calderon-Arguedas, Olger; Zambrano, Maria L.; Dasch, Gregory A.; Lindblade, Kim; Hun, Laya; Eremeeva, Marina E.; Estevez, Alejandra

2012-01-01

98

Instability of Rickettsia prowazekii RNA polymerase-promoter complexes.  

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The Rickettsia prowazekii sigma factor was overexpressed, purified, and used to reconstitute RNA polymerase holoenzyme species. R. prowazekii RNA polymerase-promoter complexes were unstable and remained dissociable and heparin sensitive under conditions in which the corresponding Escherichia coli co...

Aniskovitch, L P; Winkler, H H

99

Zoonotic surveillance for rickettsiae in domestic animals in Kenya.  

UK PubMed Central (United Kingdom)

Abstract Rickettsiae are obligate intracellular bacteria that cause zoonotic and human diseases. Arthropod vectors, such as fleas, mites, ticks, and lice, transmit rickettsiae to vertebrates during blood meals. In humans, the disease can be life threatening. This study was conducted amidst rising reports of rickettsioses among travelers to Kenya. Ticks and whole blood were collected from domestic animals presented for slaughter at major slaughterhouses in Nairobi and Mombasa that receive animals from nearly all counties in the country. Blood samples and ticks were collected from 1019 cattle, 379 goats, and 299 sheep and were screened for rickettsiae by a quantitative PCR (qPCR) assay (Rick17b) using primers and probe that target the genus-specific 17-kD gene (htrA). The ticks were identified using standard taxonomic keys. All Rick17b-positive tick DNA samples were amplified and sequenced with primers sets that target rickettsial outer membrane protein genes (ompA and ompB) and the citrate-synthase encoding gene (gltA). Using the Rick17b qPCR, rickettsial infections in domestic animals were found in 25/32 counties sampled (78.1% prevalence). Infection rates were comparable in cattle (16.3%) and sheep (15.1%) but were lower in goats (7.1%). Of the 596 ticks collected, 139 had rickettsiae (23.3%), and the detection rates were highest in Amblyomma (62.3%; n=104), then Rhipicephalus (45.5%; n=120), Hyalomma (35.9%; n=28), and Boophilus (34.9%; n=30). Following sequencing, 104 out of the 139 Rick17b-positive tick DNA had good reverse and forward sequences for the 3 target genes. On querying GenBank with the generated consensus sequences, homologies of 92-100% for the following spotted fever group (SFG) rickettsiae were identified: Rickettsia africae (93.%, n=97), Rickettsia aeschlimannii (1.9%, n=2), Rickettsia mongolotimonae (0.96%, n=1), Rickettsia conorii subsp. israelensis (0.96%, n=1), Candidatus Rickettsia kulagini (0.96% n=1), and Rickettsia spp. (1.9% n=2). In conclusion, molecular methods were used in this study to detect and identify rickettsial infections in domestic animals and ticks throughout Kenya.

Mutai BK; Wainaina JM; Magiri CG; Nganga JK; Ithondeka PM; Njagi ON; Jiang J; Richards AL; Waitumbi JN

2013-06-01

100

Zoonotic surveillance for rickettsiae in domestic animals in Kenya.  

Science.gov (United States)

Abstract Rickettsiae are obligate intracellular bacteria that cause zoonotic and human diseases. Arthropod vectors, such as fleas, mites, ticks, and lice, transmit rickettsiae to vertebrates during blood meals. In humans, the disease can be life threatening. This study was conducted amidst rising reports of rickettsioses among travelers to Kenya. Ticks and whole blood were collected from domestic animals presented for slaughter at major slaughterhouses in Nairobi and Mombasa that receive animals from nearly all counties in the country. Blood samples and ticks were collected from 1019 cattle, 379 goats, and 299 sheep and were screened for rickettsiae by a quantitative PCR (qPCR) assay (Rick17b) using primers and probe that target the genus-specific 17-kD gene (htrA). The ticks were identified using standard taxonomic keys. All Rick17b-positive tick DNA samples were amplified and sequenced with primers sets that target rickettsial outer membrane protein genes (ompA and ompB) and the citrate-synthase encoding gene (gltA). Using the Rick17b qPCR, rickettsial infections in domestic animals were found in 25/32 counties sampled (78.1% prevalence). Infection rates were comparable in cattle (16.3%) and sheep (15.1%) but were lower in goats (7.1%). Of the 596 ticks collected, 139 had rickettsiae (23.3%), and the detection rates were highest in Amblyomma (62.3%; n=104), then Rhipicephalus (45.5%; n=120), Hyalomma (35.9%; n=28), and Boophilus (34.9%; n=30). Following sequencing, 104 out of the 139 Rick17b-positive tick DNA had good reverse and forward sequences for the 3 target genes. On querying GenBank with the generated consensus sequences, homologies of 92-100% for the following spotted fever group (SFG) rickettsiae were identified: Rickettsia africae (93.%, n=97), Rickettsia aeschlimannii (1.9%, n=2), Rickettsia mongolotimonae (0.96%, n=1), Rickettsia conorii subsp. israelensis (0.96%, n=1), Candidatus Rickettsia kulagini (0.96% n=1), and Rickettsia spp. (1.9% n=2). In conclusion, molecular methods were used in this study to detect and identify rickettsial infections in domestic animals and ticks throughout Kenya. PMID:23477290

Mutai, Beth K; Wainaina, James M; Magiri, Charles G; Nganga, Joseph K; Ithondeka, Peter M; Njagi, Obadiah N; Jiang, Ju; Richards, Allen L; Waitumbi, John N

2013-03-11

 
 
 
 
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Afebrile spotted fever group Rickettsia infection after a bite from a Dermacentor variabilis tick infected with Rickettsia montanensis.  

UK PubMed Central (United Kingdom)

Several spotted fever group rickettsiae (SFGR) previously believed to be nonpathogenic are speculated to contribute to infections commonly misdiagnosed as Rocky Mountain spotted fever (RMSF) in the United States, but confirmation is difficult in cases with mild or absent systemic symptoms. We report an afebrile rash illness occurring in a patient 4 days after being bitten by a Rickettsia montanensis-positive Dermacentor variabilis tick. The patient's serological profile was consistent with confirmed SFGR infection.

McQuiston JH; Zemtsova G; Perniciaro J; Hutson M; Singleton J; Nicholson WL; Levin ML

2012-12-01

102

Evaluation of a PCR assay for quantitation of Rickettsia rickettsii and closely related spotted fever group rickettsiae.  

UK PubMed Central (United Kingdom)

A spotted fever rickettsia quantitative PCR assay (SQ-PCR) was developed for the detection and enumeration of Rickettsia rickettsii and other closely related spotted fever group rickettsiae. The assay is based on fluorescence detection of SYBR Green dye intercalation in a 154-bp fragment of the rOmpA gene during amplification by PCR. As few as 5 copies of the rOmpA gene of R. rickettsii can be detected. SQ-PCR is suitable for quantitation of R. rickettsii and 10 other genotypes of spotted fever group rickettsiae but not for R. akari, R. australis, R. bellii, or typhus group rickettsiae. The sensitivity of SQ-PCR was comparable to that of a plaque assay using centrifugation for inoculation. The SQ-PCR assay was applied successfully to the characterization of rickettsial stock cultures, the replication of rickettsiae in cell culture, the recovery of rickettsial DNA following different methods of extraction, and the quantitation of rickettsial loads in infected animal tissues, clinical samples, and ticks.

Eremeeva ME; Dasch GA; Silverman DJ

2003-12-01

103

First Detection of Spotted Fever Group Rickettsiae in Ixodes ricinus from Italy  

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Ixodes ricinus from Italy were examined for the first time to detect whether rickettsiae were present. Using molecular methods, we detected three different spotted fever group rickettsiae, including Rickettsia helvetica. Our results raise the possibility that bacteria other than R. conorii are involved in rickettsial diseases in Italy.

Beninati, Tiziana; Noda, Hiroaki; Esposito, Fulvio; Rizzoli, Annapaola; Favia, Guido; Genchi, Claudio

2002-01-01

104

Directional actin polymerization associated with spotted fever group Rickettsia infection of Vero cells.  

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Members of the spotted fever group (SFG) of rickettsiae spread rapidly from cell to cell by an unknown mechanism(s). Staining of Rickettsia rickettsii-infected Vero cells with rhodamine phalloidin demonstrated unique actin filaments associated with one pole of intracellular rickettsiae. F-actin tail...

Heinzen, R A; Hayes, S F; Peacock, M G; Hackstadt, T

105

ISOLATION OF Rickettsia bellii FROM Amblyomma ovale AND Amblyomma incisum TICKS FROM SOUTHERN BRAZIL/ AISLAMIENTO DE Rickettsia bellii A PARTIR DE GARRAPATAS Amblyomma ovale Y Amblyomma incisum PROCEDENTES DEL SUR DE BRASIL  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Objetivo. Aislar Rickettsias mediante cultivo celular a partir de muestras de garrapatas Amblyomma ovale y Amblyomma incisum del estado de São Paulo Materiales y métodos. A. ovale y A. incisum adultas de vida libre fueron colectadas en una área de selva tropical Atlántica en el estado de São Paulo, Brazil. Cada garrapata fue sometida a la prueba de hemolinfa, las garrapatas positivas en esta prueba fueron evaluadas con la técnica de shell vial con el propósito de a (more) islar rickettsias en cultivo de células Vero. Pasajes celulares de los aislados fueron identificados genotípicamente por la reacción en cadena por la polimerasa (PCR) dirigidos a fragmentos de tres genes de rickettsias (gltA, htrA y ompA), seguido por secuenciación de ADN. Resultados. Un total de 388 A. incisum y 50 A. ovale fueron colectadas. Por la prueba de hemolinfa, únicamente una A. incisum y una A. ovale fueron positivas. Las Rickettsias fueron exitosamente aisladas de estas garrapatas. Sin embargo, el cultivo continuo en células Vero fue posible sólo para la garrapata A. ovale, debido a contaminación bacteriana en el primer pasaje celular de la muestra de A. incisum. Los productos de PCR fueron obtenidos con los primers gltA y htrA para los dos aislados, no obstante, ningún producto fue obtenido con los primers ompA. Por análisis BLAST, secuencias parciales de gltA y htrA procedentes de los aislados de A. ovale y A. incisum fueron similares a las secuencias correspondientes a R. bellii. Conclusiones. Este es el primer reporte de R. bellii infectando A. incisum y el primer establecimiento exitoso de un aislado de A. ovale. Abstract in english Objective. To isolate and characterize rickettsiae from the ticks Amblyomma ovale and Amblyomma incisum collected in the state of São Paulo. Materials and methods. Adult, free-living A. ovale and A. incisum were collected in an Atlantic rainforest area in the state of São Paulo, Brazil. Each tick was tested using the hemolymph assay; samples from positive ticks were placed in shell vials in order to isolate rickettsiae and subsequently grown in Vero cells. Amplification (more) of three rickettsial genes (gltA, htrA and ompA) was attempted using polymerase chain reaction (PCR) for each isolate obtained. Amplicons were subsequently sequenced. Results. A total of 388 A. incisum and 50 A. ovale were collected. Only one A. incisum and one A. ovale were hemolymph-test positive. Rickettsiae were successfully isolated from these ticks; however establishment in Vero cell culture was successful only for the isolate from A. ovale. Bacterial contamination in the first cell passage of the A. incisum isolate precluded successful isolation of the organism. PCR products were obtained with the gltA and htrA primers for the two isolates, but no product was obtained with the ompA primers. By BLAST analysis, partial gltA and htrA sequences of isolates from A. ovale and A. incisum were similar to the corresponding sequences of R. bellii. Conclusions. This is the first report of R. bellii infecting A. incisum and the first successful isolation from A. ovale.

Pacheco, Richard; Rosa, Simone; Richtzenhain, Leonardo; Szabó, Matias P. J.; Labruna, Marcelo B

2008-05-01

106

Genomic identification of Rickettsia slovaca among spotted fever group rickettsia isolates from Dermacentor marginatus in Armenia.  

UK PubMed Central (United Kingdom)

Restriction fragment length polymorphism (RFLP) analysis of polymerase chain reaction (PCR) amplified genes was used for genomic identification of Armenian isolates of the Spotted fever group (SFG) rickettsiae with unclear taxonomic position. Analysis was performed by using one genus-specific primer pair derived from R. prowazekii citrate synthase gene and two species-specific primer pairs derived from R. rickettsii genes for 190 K and 120 K antigens following AluI, PstI and RsaI digestion of amplicons. All tested rickettsial SFG Armenian isolates from Dermacentor marginatus were identified as R. slovaca. The geographic distribution and genetic homogeneity of R. slovaca strains are discussed.

Balayeva NM; Eremeeva ME; Raoult D

1994-12-01

107

Urban focus of Rickettsia typhi and Rickettsia felis in Los Angeles, California.  

UK PubMed Central (United Kingdom)

Classic murine typhus, caused by Rickettsia typhi, is endemic in the continental United States in areas of Texas and southern California. We conducted an environmental investigation in an urban area of Los Angeles identified as the probable exposure site for a case of murine typhus. Four Rattus norvegicus heavily infested with Xenopsylla cheopis (average 32.5 fleas per animal, range 20-42) were trapped, and fleas, blood, and tissues were collected. DNAs from all specimens were tested for R. typhi and Rickettsia felis using a TaqMan assay targeting the rickettsial citrate synthase gene. Although rickettsiemia was not detected, DNA of R. felis was detected in at least one tissue from each rat. Tissues from 3 rats were also positive for R. typhi DNA. R. typhi and R. felis DNAs were detected in fleas collected from each animal with average minimal infection rates of 10% and 32.3%, respectively. Although R. typhi still circulates in urban Los Angeles in the classic Oriental flea-rat cycle, R. felis is more prevalent, even in this association.

Abramowicz KF; Rood MP; Krueger L; Eremeeva ME

2011-07-01

108

Seroprevalence of Rickettsia typhi and Rickettsia conorii infection among rodents and dogs in Egypt.  

UK PubMed Central (United Kingdom)

A serological survey of 1813 rodent and 549 dog sera, collected from 1979 to 1986 from animals in 16 Egyptian Governorates were tested for antibody to Rickettsia typhi and Rickettsia conorii by the indirect fluorescent antibody test. Only three of 82 (4%) sera from Rattus rattus collected near Aswan had antibody to R. conorii. The prevalence of R. typhi antibody in dog sera was only 0.4% (n = 549) while 25% (n = 547) of Rattus norvegicus and 11% (n = 1138) of R. rattus had measurable antibodies. Among the other rodents, antibody was demonstrated in only 2% (n = 45) of Arvicanthis spp., and 1% (n = 83) of Acomys spp. Collectively, rodents captured in the Nile Delta had a higher prevalence (mean 24% (n = 787] than those captured in the Nile Valley (mean 4% (n = 650]. Antibody to R. typhi was detected in rodents collected in all port cities: ismailiya, 13%; Port Said, 9%; Suez, 9%; Safaga, 16%; Quseir, 32% and Alexandria, 34%. These data showed evidence of R. typhi infection among rodents in widespread geographic localities of Egypt and suggested that infected rodents may be a source of human infections.

Soliman AK; Botros BA; Ksiazek TG; Hoogstraal H; Helmy I; Morrill JC

1989-10-01

109

Seroprevalence of Rickettsia typhi and Rickettsia conorii infection among rodents and dogs in Egypt.  

Science.gov (United States)

A serological survey of 1813 rodent and 549 dog sera, collected from 1979 to 1986 from animals in 16 Egyptian Governorates were tested for antibody to Rickettsia typhi and Rickettsia conorii by the indirect fluorescent antibody test. Only three of 82 (4%) sera from Rattus rattus collected near Aswan had antibody to R. conorii. The prevalence of R. typhi antibody in dog sera was only 0.4% (n = 549) while 25% (n = 547) of Rattus norvegicus and 11% (n = 1138) of R. rattus had measurable antibodies. Among the other rodents, antibody was demonstrated in only 2% (n = 45) of Arvicanthis spp., and 1% (n = 83) of Acomys spp. Collectively, rodents captured in the Nile Delta had a higher prevalence (mean 24% (n = 787] than those captured in the Nile Valley (mean 4% (n = 650]. Antibody to R. typhi was detected in rodents collected in all port cities: ismailiya, 13%; Port Said, 9%; Suez, 9%; Safaga, 16%; Quseir, 32% and Alexandria, 34%. These data showed evidence of R. typhi infection among rodents in widespread geographic localities of Egypt and suggested that infected rodents may be a source of human infections. PMID:2509729

Soliman, A K; Botros, B A; Ksiazek, T G; Hoogstraal, H; Helmy, I; Morrill, J C

1989-10-01

110

[Spotted fever: isolation of Rickettsia from a skin biopsy sample  

UK PubMed Central (United Kingdom)

A 2 years old child living in an area of the State of São Paulo, known in the past as endemic for rickettsiosis developed clinical evidences of spotted fever after a tick bite. Rickettsiae were isolated from guinea pigs inoculated with a skin homogenate. In sera tested by indirect immunofluorescence with Rickettsia rickettsii standard antigen, IgG specific antibody titers raised from 1:512 in the first sample to 1:2048 in the third one; IgM specific antibody titer was 1:128 in the three samples. Also positive were sera obtained from the inoculated guinea pigs. In the last 20 years no other case of rickettsial spotted fever has been confirmed by isolation of the agent in Brasil. To our knowledge, there are no previous reports of isolation of Rickettsiae through inoculation of skin biopsy homogenates.

Melles HH; Colombo S; da Silva MV

1992-01-01

111

Rickettsia sp. closely related to Rickettsia raoultii (Rickettsiales: Rickettsiaceae) in an Amblyomma helvolum (Acarina: Ixodidae) tick from a Varanus salvator (Squamata: Varanidae) in Thailand.  

UK PubMed Central (United Kingdom)

An engorged female Amblyomma helvolum Koch tick was removed from an adult Varanus salvator Laurenti lizard during field collection in Thailand. After using polymerase chain reaction to amplify three genes (16S rDNA, gltA, and OmpA), we discovered the presence of a Rickettsia sp. of the Spotted Fever Group. Phylogenetic analysis revealed that this Rickettsia sp. is closely related to Rickettsia raoultii Mediannikov. Therefore, we report herein for the first time the detection of a novel Spotted Fever Group Rickettsia in an Amblyomma helvolum from a Varanus salvator in Thailand.

Doornbos K; Sumrandee C; Ruang-Areerate T; Baimai V; Trinachartvanit W; Ahantarig A

2013-01-01

112

Serological identification of Rickettsia spp from the spotted fever group in capybaras in the region of Campinas - SP - Brazil Identificação sorológica de Rickettsia spp do grupo da febre maculosa em capivaras na região de Campinas, SP, Brasil  

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Full Text Available Diseases transmitted by ticks have been an important health problem all over the world. Brazilian Spotted Fever (BSF) stands for a serious epidemiological concern due to the high mortality rates pointed out. Capybaras are commonly incriminated as possible reservoirs in the BSF transmission cycle. In the last decades the numbers of these animals raised sharply and they have invaded human areas. They intensify the contact between ticks and humans beings. This study aim is to contribute to the possible role performed for this rodent in the BSF epidemiology in some areas located in Campinas region, São Paulo. Cabybaras infected by rickettsiae of BSF group were studied through the analysis of the frequencies of BSF-group rickettisae antibodies titer = 64 by indirect immunofluorescence test (IFA), and data from human cases epidemiological surveillance. The serum frequency positiveness varied greatly according to areas where animals were captured. However it was found serum positiviness only in the areas where human cases of BSF were reported. These findings suggest the capybara may be seen as sentinel animal. Due to presence of serological cross reactivity between microorganisms belonging to SF group, the results must be interpreted carefully and additional methods to distinguish pathogenic rickettsiae are required in our country.Doenças transmitidas por carrapatos vêm sendo um importante problema de saúde pública no mundo. A Febre Maculosa Brasileira (FMB) representa um sério risco epidemiológico devido às altas taxas de letalidade apresentadas. As capivaras são freqüentemente incriminadas como possíveis reservatórios no ciclo de transmissão da FMB. Nas últimas décadas o número desses animais cresceu intensamente e eles invadiram os espaços humanos. As capivaras intensificam o contato entre carrapatos e seres humanos na medida em que se apresentam muito infestadas por estes parasitos. O objetivo deste estudo é contribuir para o conhecimento do possível papel desempenhado por este roedor na epidemiologia da FMB em algumas áreas da região de Campinas, SP. Foi estudada a infecção das capivaras por rickettsias do grupo da FMB, por meio da análise das freqüências de anticorpos contra este grupo, nestes animais, e dados da vigilância epidemiológica de casos humanos. A freqüência desses anticorpos variou amplamente entre as localidades, entretanto, só foram encontrados soros com anticorpos com titulagem =64 naquelas onde havia notificação de casos humanos. Estes achados sugerem que a capivara poderá ser um animal sentinela. No entanto, devido à ocorrência de reação cruzada entre os microorganismos do grupo de FM estes resultados devem ser interpretados com cautela e são necessários métodos capazes de distinguir rickettsias patogênicas.

Celso Eduardo de Souza; Savina Silvana Lacerra de Souza; Virgília Luna Castor Lima; Simone Berger Calic; Maria Cecilia Gibrail Oliveira Camargo; Elisa San Martin Mouriz Savani; Sandra Regina Nicoletti D'Auria; Arício Xavier Linhares; Natalino Hajime Yoshinari

2008-01-01

113

Serological identification of Rickettsia spp from the spotted fever group in capybaras in the region of Campinas - SP - Brazil/ Identificação sorológica de Rickettsia spp do grupo da febre maculosa em capivaras na região de Campinas, SP, Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Doenças transmitidas por carrapatos vêm sendo um importante problema de saúde pública no mundo. A Febre Maculosa Brasileira (FMB) representa um sério risco epidemiológico devido às altas taxas de letalidade apresentadas. As capivaras são freqüentemente incriminadas como possíveis reservatórios no ciclo de transmissão da FMB. Nas últimas décadas o número desses animais cresceu intensamente e eles invadiram os espaços humanos. As capivaras intensificam o con (more) tato entre carrapatos e seres humanos na medida em que se apresentam muito infestadas por estes parasitos. O objetivo deste estudo é contribuir para o conhecimento do possível papel desempenhado por este roedor na epidemiologia da FMB em algumas áreas da região de Campinas, SP. Foi estudada a infecção das capivaras por rickettsias do grupo da FMB, por meio da análise das freqüências de anticorpos contra este grupo, nestes animais, e dados da vigilância epidemiológica de casos humanos. A freqüência desses anticorpos variou amplamente entre as localidades, entretanto, só foram encontrados soros com anticorpos com titulagem =64 naquelas onde havia notificação de casos humanos. Estes achados sugerem que a capivara poderá ser um animal sentinela. No entanto, devido à ocorrência de reação cruzada entre os microorganismos do grupo de FM estes resultados devem ser interpretados com cautela e são necessários métodos capazes de distinguir rickettsias patogênicas. Abstract in english Diseases transmitted by ticks have been an important health problem all over the world. Brazilian Spotted Fever (BSF) stands for a serious epidemiological concern due to the high mortality rates pointed out. Capybaras are commonly incriminated as possible reservoirs in the BSF transmission cycle. In the last decades the numbers of these animals raised sharply and they have invaded human areas. They intensify the contact between ticks and humans beings. This study aim is t (more) o contribute to the possible role performed for this rodent in the BSF epidemiology in some areas located in Campinas region, São Paulo. Cabybaras infected by rickettsiae of BSF group were studied through the analysis of the frequencies of BSF-group rickettisae antibodies titer = 64 by indirect immunofluorescence test (IFA), and data from human cases epidemiological surveillance. The serum frequency positiveness varied greatly according to areas where animals were captured. However it was found serum positiviness only in the areas where human cases of BSF were reported. These findings suggest the capybara may be seen as sentinel animal. Due to presence of serological cross reactivity between microorganisms belonging to SF group, the results must be interpreted carefully and additional methods to distinguish pathogenic rickettsiae are required in our country.

Souza, Celso Eduardo de; Souza, Savina Silvana Lacerra de; Lima, Virgília Luna Castor; Calic, Simone Berger; Camargo, Maria Cecilia Gibrail Oliveira; Savani, Elisa San Martin Mouriz; D'Auria, Sandra Regina Nicoletti; Linhares, Arício Xavier; Yoshinari, Natalino Hajime

2008-09-01

114

Detection of spotted fever group rickettsia^s DNA in patient^s blood samples by polymerase chain reaction technology  

UK PubMed Central (United Kingdom)

The spotted fever group(SFG) rickettsial DNA in Patient^s blood samples were detected directly by a dual polymerase chain reaction (PCR). One of the seven samples was positive. Further analysis by restriction fragment length polymorphism (RFLP) showed that the genotype was the same as that of Heilongjiang Rickettsias. These results indicated that Heilongjiang Rickettsia can cause disease in human, and that PCR technology is a rapid simple and sensitive method which can be used as early diagnose of SFG rickttsiosis and the characterization of their genomic typing.

Wu Yimin; Liu Xinxin; Hu Lingmei; Wei Anming; Zhang Zhiqiang; Yang Qing

1998-01-01

115

Seroepidemiology of Rickettsia typhi, spotted fever group rickettsiae, and Coxiella burnetti infection in pregnant women from urban Tanzania.  

UK PubMed Central (United Kingdom)

Immunofluorescent antibody (IFA) testing was performed on sera drawn from 150 pregnant women in the port city of Dar es Salaam, Tanzania. Prevalence of antibodies to Rickettsia typhi was 28%, higher than in any of the 12 other African countries in which serosurveys using IFA testing have been performed. Seroprevalence of antibodies to spotted fever group rickettsiae antigens was 25.3%, comparable with that found in other sub-Saharan countries endemic for Amblyomma ticks. Only 4.7% of women were seropositive for Coxiella burnetii.

Anstey NM; Tissot Dupont H; Hahn CG; Mwaikambo ED; McDonald MI; Raoult D; Sexton DJ

1997-08-01

116

Detection of Rickettsia spp. and host and habitat associations of fleas (Siphonaptera) in eastern Taiwan.  

UK PubMed Central (United Kingdom)

Rickettsia typhi and Rickettsia felis (Rickettsiales: Rickettsiaceae) are two rickettsiae principally transmitted by fleas, but the detection of either pathogen has rarely been attempted in Taiwan. Of 2048 small mammals trapped in eastern Taiwan, Apodemus agrarius Pallas (24.5%) and Mus caroli Bonhote (24.4%) (both: Rodentia: Muridae) were the most abundant, and M. caroli hosted the highest proportion of fleas (63.9% of 330 fleas). Two flea species were identified: Stivalius aporus Jordan and Rothschild (Siphonaptera: Stivaliidae), and Acropsylla episema Rothschild (Siphonaptera: Leptopsyllidae). Nested polymerase chain reaction targeting parts of the ompB and gltA genes showed six fleas to be positive for Rickettsia spp. (3.8% of 160 samples), which showed the greatest similarity to R. felis, Rickettsia japonica, Rickettsia conorii or Rickettsia sp. TwKM01. Rickettsia typhi was not detected in the fleas and Rickettsia co-infection did not occur. Both flea species were more abundant during months with lower temperatures and less rainfall, and flea abundance on M. caroli was not related to soil hardness, vegetative height, ground cover by litter or by understory layer, or the abundance of M. caroli. Our study reveals the potential circulation of R. felis and other rickettsiae in eastern Taiwan, necessitating further surveillance of rickettsial diseases in this region. This is especially important because many novel rickettsioses are emerging worldwide.

Kuo CC; Huang JL; Lin TE; Wang HC

2012-09-01

117

Rickettsia rickettsii transmission by a lone star tick, North Carolina.  

UK PubMed Central (United Kingdom)

Only indirect or circumstantial evidence has been published to support transmission of Rickettsia rickettsii by Amblyomma americanum (lone star) ticks in North America. This study provides molecular evidence that A. americanum ticks can function, although most likely infrequently, as vectors of Rocky Mountain spotted fever for humans.

Breitschwerdt EB; Hegarty BC; Maggi RG; Lantos PM; Aslett DM; Bradley JM

2011-05-01

118

Amblyomma imitator ticks as vectors of Rickettsia rickettsii, Mexico.  

UK PubMed Central (United Kingdom)

Real-time PCR of Amblyomma imitator tick egg masses obtained in Nuevo Leon State, Mexico, identified a Rickettsia species. Sequence analyses of 17-kD common antigen and outer membrane protein A and B gene fragments showed to it to be R. rickettsii, which suggested a potential new vector for this bacterium.

Oliveira KA; Pinter A; Medina-Sanchez A; Boppana VD; Wikel SK; Saito TB; Shelite T; Blanton L; Popov V; Teel PD; Walker DH; Galvao MA; Mafra C; Bouyer DH

2010-08-01

119

Experimental Infection of Amblyomma aureolatum Ticks with Rickettsia rickettsii  

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We experimentally infected Amblyomma aureolatum ticks with the bacterium Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever (RMSF). These ticks are a vector for RMSF in Brazil. R. rickettsii was efficiently conserved by both transstadial maintenance and vertical (transovarial...

Labruna, Marcelo B.; Ogrzewalska, Maria; Soares, João F.; Martins, Thiago F.; Soares, Herbert S.; Moraes-Filho, Jonas

120

Detection and Localization of Rickettsia sp in Mealybug.  

Science.gov (United States)

Mealybug, Phenacoccus solenopsis Tinsley, is a sap-sucking hemipteran insect. It is an agricultural pest that is now widely distributed in India. In this study we report the presence of Rickettsia from P. solenopsis. We constructed a 16S rRNA gene library to study the bacterial diversity associated with this insect and we found that all the clones from the library were only of Candidatus Tremblaya phenacola. This study also highlights that the normal protocol adopted to study the bacterial diversity from environmental sample, by preparation of a 16S rRNA gene library, does not work when the bacterial population is highly skewed in favor of one bacteria (primary endosymbiont in this case). Hence, we used bacterial genus specific polymerase chain reaction primers to test the presence of any of the widely known secondary endosymbionts associated with insects. We tested for the presence of Cardinium, Rickettsia, Wolbachia, and Arsenophonus in P. solenopsis collected from 10 different locations across India. Only Rickettsia was detected from four locations while we were not able to find any other bacteria. We confirmed the presence of these bacteria by localizing Rickettsia and the primary endosmbiont, Candidatus Tremblaya sp. to the bacteriocyte of P. solenopsis using fluorescent in situ hybridization. PMID:23905733

Singh, Shalini Thakur; Kumar, Jitendra; Thomas, Asha; Ramamurthy, V V; Rajagopal, R

2013-08-01

 
 
 
 
121

Detection and Localization of Rickettsia sp in Mealybug.  

UK PubMed Central (United Kingdom)

Mealybug, Phenacoccus solenopsis Tinsley, is a sap-sucking hemipteran insect. It is an agricultural pest that is now widely distributed in India. In this study we report the presence of Rickettsia from P. solenopsis. We constructed a 16S rRNA gene library to study the bacterial diversity associated with this insect and we found that all the clones from the library were only of Candidatus Tremblaya phenacola. This study also highlights that the normal protocol adopted to study the bacterial diversity from environmental sample, by preparation of a 16S rRNA gene library, does not work when the bacterial population is highly skewed in favor of one bacteria (primary endosymbiont in this case). Hence, we used bacterial genus specific polymerase chain reaction primers to test the presence of any of the widely known secondary endosymbionts associated with insects. We tested for the presence of Cardinium, Rickettsia, Wolbachia, and Arsenophonus in P. solenopsis collected from 10 different locations across India. Only Rickettsia was detected from four locations while we were not able to find any other bacteria. We confirmed the presence of these bacteria by localizing Rickettsia and the primary endosmbiont, Candidatus Tremblaya sp. to the bacteriocyte of P. solenopsis using fluorescent in situ hybridization.

Singh ST; Kumar J; Thomas A; Ramamurthy VV; Rajagopal R

2013-08-01

122

An infection of Ruditapes decussatus (Bivalvia) by Rickettsia  

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The authors report the presence of a Rickettsia in Ruditapes decussatus from natural populations of the Algarve (Portugal). Light microscopic shows infections of varying importance in gill tissues. Some enclose small procaryotic colonies (cp) scattered in all lamellae; in others, the colonies are sc...

Mialhe Eric; Chagot Dominique; Boulo Viviane; Comps Michel; Ruano Francisco; Grizel Henri

123

Human infection with Rickettsia sibirica mongolitimonae, Spain, 2007-2011.  

UK PubMed Central (United Kingdom)

Human infection with Rickettsia sibirica mongolitimonae was initially reported in 1996, and reports of a total of 18 cases have been published. We describe 6 additional cases that occurred in the Mediterranean coast region of Spain during 2007-2011. Clinicians should consider this infection in patients who have traveled to this area.

Ramos JM; Jado I; Padilla S; Masiá M; Anda P; Gutiérrez F

2013-02-01

124

Acquisition of Rickettsia felis by Cat Fleas During Feeding  

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Evidence for horizontal routes of transmission for Rickettsia felis has come from detection of R. felis infection in vertebrates and multiple blood-feeding arthropods; however, infection of cat fleas, Ctenocephalides felis, during blood feeding has not been demonstrated. In this study, the ability o...

Reif, Kathryn E.; Kearney, Michael T.; Foil, Lane D.; Macaluso, Kevin R.

125

A ocorrência de riquetsioses do grupo Rickettsia rickettsii Occurrence of rickettsiosis of the group Rickettsia rickettsii  

Directory of Open Access Journals (Sweden)

Full Text Available Foi realizada revisão da literatura com objetivo de atualizar as informações sobre a ocorrência de riquetsioses do grupo Rickettsia rickettsii. Verificou-se que nos EUA e Europa, a incidência da febre maculosa, vem aumentando desde 1970 até hoje. No Brasil, foi relatado um caso presuntivo, no estado da Bahia, em 1979. Com relação a prevenção, controle e tratamento dessa doença é salientada a importância de informações relacionadas com indivíduos expostos a picadas de carrapatos, notificação de novos casos, fatores ecológicos, técnicas laboratoriais mais específicas para a identificação do agente etiológico, e a antibioticoterapia mais eficiente. A vacinação é ainda referida como meio mais favorável na prevenção da doença, devendo ser administrada aos indivíduos de alto risco. No Brasil, faltam informações precisas sobre a ocorrência de R. rickettsii.A search of the literature to update the available information on the occurrence of rickettsiosis caused by the Rickettsia rickettsii group was made. It was verified that the incidence of spotted fever has had an increase in the U.S.A. and Europe since 1970. In Brazil, a presumptive case was reported in the State of Bahia, in 1979. Regarding the prevention, control and treatment of this disease, importance is given to data related to individuals exposed to tick bites, report of new cases, ecological factors, more specific laboratorial procedures for the identification of the etiological agent, and a more efficient antibiotic therapy. Vaccination is still regarded as the most adequate means for the prevention of the disease, and should be aimed at groups of individuals at high risk. In Brazil, there is a lack of more precise information on the occurrence of R. rickettsii.

Dalva A. Portari Mancini; Elvira M. Mendes Nascimento; Valéria Rosa Tavares; Murillo Adelino Soares

1983-01-01

126

Mapping of Monoclonal Antibody Binding Sites on CNBr Fragments of the S-Layer Protein Antigens of Rickettsia Typhi and Rickettsia Prowazekii. (Reannouncement with New Availability Information).  

Science.gov (United States)

The 120 kDa surface protein antigens (SPAs) of typhus rickettsiae lie external to the outer membrane in regular arrays and chemically resemble the S-layer proteins of other bacteria. These proteins elicit protective immune responses against the rickettsia...

W. M. Ching M. Carl G. A. Dasch

1992-01-01

127

Characterization of and application of monoclonal antibodies against Rickettsia africae, a newly recognized species of spotted fever group rickettsia.  

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Rickettsia africae is a newly described species which causes African tick bite fever. Mediterranean spotted fever caused by R. conorii is endemic in the same regions of Africa as tick bite fever, and differentiation of the two syndromes by characterization of their etiological agents is important fo...

Xu, W; Beati, L; Raoult, D

128

Use of DNA sequences for Rickettsia identification in Ixodes ricinus ticks: the first detection of Rickettsia monacensis in Poland.  

UK PubMed Central (United Kingdom)

The cosmopolitan tick Ixodes ricinus inhabiting Europe, including Poland, is a vector for many pathogens, such as various Rickettsia species, which spread to new territories. They are present mainly in the Mediterranean countries, but have also been found in Central Europe at increasing frequency. In the present study, the gltA gene, encoding citrate synthase, and an internal transcribed spacer (ITS) were employed to detect the DNA and identify the species of tick-borne pathogens of the Rickettsia genus. The presence of bacterial DNA was detected in 9.5% of the examined I. ricinus individuals. Based on the nucleotide sequences of the analysed genomic fragments, most pathogens were identified as Rickettsia helvetica, while Rickettsia monacensis was revealed in one case. We have described for the first time, to our knowledge, the occurrence of this species in Poland. Both markers employed in the experiments were successful in species identification of R. helvetica. The newly described species R. monacensis may be identified by the protein-coding gene, but the ITS nucleotide sequences proved insufficient.

Rymaszewska A; Piotrowski M

2013-02-01

129

Detection of Rickettsia parkeri and Candidatus Rickettsia andeanae in Amblyomma maculatum Gulf Coast ticks collected from humans in the United States.  

UK PubMed Central (United Kingdom)

Rickettsia parkeri, a spotted fever group (SFG) rickettsia recently found to be pathogenic to humans, causes an eschar-associated febrile illness. The R. parkeri rickettsiosis, Tidewater spotted fever, has been misdiagnosed as Rocky Mountain spotted fever due to serologic cross reactivity and the lack of specific diagnostic methods. Candidatus Rickettsia andeanae, also a SFG rickettsia, is a recently described agent of unknown pathogenicity originally identified in ticks collected from domestic animals during a fever outbreak investigation in northern Peru. Among 37 Amblyomma maculatum (collected from humans (n=35) and questing (n=2)) obtained from the southern United States during 2000-2009, nine and four A. maculatum nucleic acid preparations were found positive for R. parkeri and Candidatus R. andeanae, respectively, by newly developed genus- and species-specific quantitative real-time polymerase chain reaction assays. In addition Rickettsia felis was found in two A. maculatum nucleic acid preparations.

Jiang J; Stromdahl EY; Richards AL

2012-03-01

130

Spotted fever group rickettsiae in Dermacentor reticulatus and Haemaphysalis punctata ticks in the UK.  

UK PubMed Central (United Kingdom)

BACKGROUND: Spotted fever group (SFG) rickettsiae have recently been identified for the first time in UK ticks. This included the findings of Rickettsia helvetica in Ixodes ricinus and Rickettsia raoultii in Dermacentor reticulatus. This paper further investigates the occurrence of SFG rickettsiae in additional geographically distinct populations of D. reticulatus, and for the first time, investigates the occurrence of SFG rickettsiae in UK populations of Haemaphysalis punctata ticks. METHODS: Questing D. reticulatus and H. punctata were collected at a number of sites in England and Wales. DNA from questing ticks was extracted by alkaline lysis and detection of rickettsiae DNA was performed, in addition to detection of A. phagocytophilum, N. mikurensis, C. burnetii and B. burgdorferi sensu lato. RESULTS: This paper builds on previous findings to include the detection of spotted fever Rickettsia which showed the highest homology to Rickettsia massiliae in Haemaphysalis punctata, as well as R. helvetica in D. reticulatus. The occurrence of SFG rickettsiae in D. reticulatus in the UK appears to be confined only to Welsh and Essex populations, with no evidence so far from Devon. Similarly, the occurrence of SFG rickettsiae in H. punctata appears confined to one of two farms known to be infested with this tick in North Kent, with no evidence so far from the Sussex populations. Anaplasma phagocytophilum, Neoehrlichia mikurensis, Coxiella burnetii and Borrelia burgdorferi sensu lato DNA was not detected in any of the ticks. CONCLUSION: These two tick species are highly restricted in their distribution in England and Wales, but where they do occur they can be abundant. Following detection of these SFG rickettsiae in additional UK tick species, as well as I. ricinus, research should now be directed towards clarifying firstly the geographic distribution of SFG rickettsiae in UK ticks, and secondly to assess the prevalence rates in ticks, wild and domesticated animals and humans to identify the drivers for disease transmission and their public health significance.

Tijsse-Klasen E; Hansford KM; Jahfari S; Phipps P; Sprong H; Medlock JM

2013-01-01

131

Spotted fever group rickettsiae in Dermacentor reticulatus and Haemaphysalis punctata ticks in the UK  

Science.gov (United States)

Background Spotted fever group (SFG) rickettsiae have recently been identified for the first time in UK ticks. This included the findings of Rickettsia helvetica in Ixodes ricinus and Rickettsia raoultii in Dermacentor reticulatus. This paper further investigates the occurrence of SFG rickettsiae in additional geographically distinct populations of D. reticulatus, and for the first time, investigates the occurrence of SFG rickettsiae in UK populations of Haemaphysalis punctata ticks. Methods Questing D. reticulatus and H. punctata were collected at a number of sites in England and Wales. DNA from questing ticks was extracted by alkaline lysis and detection of rickettsiae DNA was performed, in addition to detection of A. phagocytophilum, N. mikurensis, C. burnetii and B. burgdorferi sensu lato. Results This paper builds on previous findings to include the detection of spotted fever Rickettsia which showed the highest homology to Rickettsia massiliae in Haemaphysalis punctata, as well as R. helvetica in D. reticulatus. The occurrence of SFG rickettsiae in D. reticulatus in the UK appears to be confined only to Welsh and Essex populations, with no evidence so far from Devon. Similarly, the occurrence of SFG rickettsiae in H. punctata appears confined to one of two farms known to be infested with this tick in North Kent, with no evidence so far from the Sussex populations. Anaplasma phagocytophilum, Neoehrlichia mikurensis, Coxiella burnetii and Borrelia burgdorferi sensu lato DNA was not detected in any of the ticks. Conclusion These two tick species are highly restricted in their distribution in England and Wales, but where they do occur they can be abundant. Following detection of these SFG rickettsiae in additional UK tick species, as well as I. ricinus, research should now be directed towards clarifying firstly the geographic distribution of SFG rickettsiae in UK ticks, and secondly to assess the prevalence rates in ticks, wild and domesticated animals and humans to identify the drivers for disease transmission and their public health significance.

2013-01-01

132

Detection of a novel Rickettsia (Alphaproteobacteria: Rickettsiales) in rotund ticks (Ixodes kingi) from Saskatchewan, Canada.  

UK PubMed Central (United Kingdom)

A novel Rickettsia was detected in the rotund tick, Ixodes kingi Bishopp, 1911, based on comparative DNA sequence analyses of 4 genes; the rickettsial-specific 17-kDa antigen gene, citrate synthase gene (gltA), the outer surface membrane protein A gene (ompA), and the 16S rRNA gene. The rickettsiae in I. kingi differed in nucleotide sequence from those of other Rickettsia species by 5.8-18.3% for the 17-kDa gene, 0.9-13.9% for gltA, 5.5-22.8% for ompA, and 0.9-1.6% for the 16S rRNA gene. Phylogenetic analyses of the sequence data revealed that this putative new species of Rickettsia, provisionally named Candidatus Rickettsia kingi, does not belong to the spotted fever group or typhus group of rickettsiae, but represents a sister taxon to R. canadensis and Candidatus Rickettsia tarasevichiae. This novel Rickettsia was found in 60 of the 87 (69%) ticks examined, which included all feeding life cycle stages of I. kingi. Although adult I. kingi occasionally parasitize dogs and humans, it remains to be determined if this Rickettsia is pathogenic to these host species.

Anstead CA; Chilton NB

2013-04-01

133

Isolation of Rickettsia parkeri and identification of a novel spotted fever group Rickettsia sp. from Gulf Coast ticks (Amblyomma maculatum) in the United States.  

UK PubMed Central (United Kingdom)

Until recently, Amblyomma maculatum (the Gulf Coast tick) had garnered little attention compared to other species of human-biting ticks in the United States. A. maculatum is now recognized as the principal vector of Rickettsia parkeri, a pathogenic spotted fever group rickettsia (SFGR) that causes an eschar-associated illness in humans that resembles Rocky Mountain spotted fever. A novel SFGR, distinct from other recognized Rickettsia spp., has also been detected recently in A. maculatum specimens collected in several regions of the southeastern United States. In this study, 198 questing adult Gulf Coast ticks were collected at 4 locations in Florida and Mississippi; 28% of these ticks were infected with R. parkeri, and 2% of these were infected with a novel SFGR. Seventeen isolates of R. parkeri from individual specimens of A. maculatum were cultivated in Vero E6 cells; however, all attempts to isolate the novel SFGR were unsuccessful. Partial genetic characterization of the novel SFGR revealed identity with several recently described, incompletely characterized, and noncultivated SFGR, including "Candidatus Rickettsia andeanae" and Rickettsia sp. Argentina detected in several species of Neotropical ticks from Argentina and Peru. These findings suggest that each of these "novel" rickettsiae represent the same species. This study considerably expanded the number of low-passage, A. maculatum-derived isolates of R. parkeri and characterized a second, sympatric Rickettsia sp. found in Gulf Coast ticks.

Paddock CD; Fournier PE; Sumner JW; Goddard J; Elshenawy Y; Metcalfe MG; Loftis AD; Varela-Stokes A

2010-05-01

134

Artificial infection of the bed bug with Rickettsia parkeri.  

UK PubMed Central (United Kingdom)

Although a variety of disease agents have been reported from bed bugs, the mechanical and biological disease transmission potential of bed bugs remains unelucidated. In this study we assayed survivability of the mildly pathogenic spotted fever group rickettsia, Rickettsia parkeri, in bed bugs after feeding on R. parkeri-infected chicken blood. Two groups of 15 adult bed bugs each were fed on infected or noninfected blood, and two groups of fourth-instar bed bugs also were fed on either infected or noninfected blood. One group of 15 adult bed bugs received no bloodmeal and was included as an additional control. Two weeks postfeeding, two pools of five live bed bugs from each group were surface sterilized, macerated, and placed in Vero cell cultures in an attempt to grow live organism. The remaining five individual bed bugs from each group were dissected, their salivary glands were removed for immunofluorescence assay (IFA) staining, and the remaining body parts were processed for polymerase chain reaction (PCR) analysis. Results indicated that no immature (now molted to fifth instar) bed bugs were positive for R. parkeri by IFA or PCR, indicating that organisms did not survive the molting process. After 4 wk of cell culture, no organisms were seen in cultures from any of the treatment or control groups, nor were any cultures PCR positive. However, two of the adult bed bugs were IFA positive for rickettsia-like organisms, and these two specimens were also PCR positive using R. parkeri-specific primers. These IFA and PCR results indicate that remnants of Rickettsia parkeri (possibly whole organisms) survived in the bugs for 2 wk, but the viability of the organisms in these two specimens could not be determined.

Goddard J; Varela-Stokes A; Smith W; Edwards KT

2012-07-01

135

Artificial infection of the bed bug with Rickettsia parkeri.  

Science.gov (United States)

Although a variety of disease agents have been reported from bed bugs, the mechanical and biological disease transmission potential of bed bugs remains unelucidated. In this study we assayed survivability of the mildly pathogenic spotted fever group rickettsia, Rickettsia parkeri, in bed bugs after feeding on R. parkeri-infected chicken blood. Two groups of 15 adult bed bugs each were fed on infected or noninfected blood, and two groups of fourth-instar bed bugs also were fed on either infected or noninfected blood. One group of 15 adult bed bugs received no bloodmeal and was included as an additional control. Two weeks postfeeding, two pools of five live bed bugs from each group were surface sterilized, macerated, and placed in Vero cell cultures in an attempt to grow live organism. The remaining five individual bed bugs from each group were dissected, their salivary glands were removed for immunofluorescence assay (IFA) staining, and the remaining body parts were processed for polymerase chain reaction (PCR) analysis. Results indicated that no immature (now molted to fifth instar) bed bugs were positive for R. parkeri by IFA or PCR, indicating that organisms did not survive the molting process. After 4 wk of cell culture, no organisms were seen in cultures from any of the treatment or control groups, nor were any cultures PCR positive. However, two of the adult bed bugs were IFA positive for rickettsia-like organisms, and these two specimens were also PCR positive using R. parkeri-specific primers. These IFA and PCR results indicate that remnants of Rickettsia parkeri (possibly whole organisms) survived in the bugs for 2 wk, but the viability of the organisms in these two specimens could not be determined. PMID:22897053

Goddard, Jerome; Varela-Stokes, Andrea; Smith, Whitney; Edwards, Kristine T

2012-07-01

136

Rickettsia felis infection in cat fleas Ctenocephalides felis felis  

Directory of Open Access Journals (Sweden)

Full Text Available The present study evaluated the rickettsial infection in a laboratory colony of cat fleas, Ctenocephalides felis felis (Bouche) in Brazil. All flea samples (30 eggs, 30 larvae, 30 cocoons, 30 males, and 30 females) tested by polymerase chain reaction (PCR) were shown to contain rickettsial DNA. PCR products, corresponding to the rickettsial gltA, htrA, ompA and ompB gene partial sequences were sequenced and showed to correspond to Rickettsia felis, indicating that the flea colony was 100% infected by R. felis. The immunofluorescence assay (IFA) showed the presence of R. felis-reactive antibodies in blood sera of 7 (87.5%) out of 8 cats that were regularly used to feed the flea colony. From 15 humans that used to work with the flea colony in the laboratory, 6 (40.0%) reacted positively to R. felis by IFA. Reactive feline and human sera showed low endpoint titers against R. felis, varying from 64 to 256. With the exception of one human serum, all R. felis-reactive sera were also reactive to Rickettsia rickettsii and/or Rickettsia parkeri antigens at similar titers to R. felis. The single human serum that was reactive solely to R. felis had an endpoint titer of 256, indicating that this person was infected by R. felis.

Mauricio C. Horta; Fabio B. Scott; Thaís R. Correia; Julio I. Fernandes; Leonardo J. Richtzenhain; Marcelo B. Labruna

2010-01-01

137

High rates of Rickettsia parkeri infection in Gulf Coast ticks (Amblyomma maculatum) and identification of "Candidatus Rickettsia andeanae" from Fairfax County, Virginia.  

UK PubMed Central (United Kingdom)

The Gulf Coast tick, Amblyomma maculatum, is a vector of Rickettsia parkeri, a recently identified human pathogen that causes a disease with clinical symptoms that resemble a mild form of Rocky Mountain spotted fever. Because the prevalence of R. parkeri infection in geographically distinct populations of A. maculatum is not fully understood, A. maculatum specimens collected as part of a tick and pathogen surveillance system in Fairfax County, Virginia, were screened to determine pathogen infection rates. Overall, R. parkeri was found in 41.4% of the A. maculatum that were screened. Additionally, the novel spotted fever group Rickettsia sp., tentatively named "Candidatus Rickettsia andeanae," was observed for the first time in Virginia.

Fornadel CM; Zhang X; Smith JD; Paddock CD; Arias JR; Norris DE

2011-12-01

138

Determination of genome size and restriction pattern polymorphism of Rickettsia prowazekii and Rickettsia typhi by pulsed field gel electrophoresis.  

UK PubMed Central (United Kingdom)

Pulsed field gel electrophoresis (PFGE) of SmaI, MluI and SalI digested DNA was used to estimate genome size and perform restriction fragment length polymorphism analysis for Rickettsia prowazekii and Rickettsia typhi. We concluded that the genome of R. prowazekii and R. typhi consisted of a single chromosomal DNA. The total length of DNA of R. prowazekii was 1,106 +/- 54 kb and of R. typhi was 1,133 +/- 44 kb. It was possible to differentiate two strains of R. prowazekii, Breinl and EVir, by PFGE analysis after SalI digestion. Restriction fragment length polymorphism analysis did not reveal intraspecies differences between three human isolates and one Xenopsilla cheopis isolate of R. typhi.

Eremeeva ME; Roux V; Raoult D

1993-08-01

139

Anti-Rickettsia spp. antibodies in free-ranging and captive capybaras from southern Brazil/ Anticorpos anti-Rickettsia spp. em capivaras de vida livre e de cativeiro no Sul do Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese As capivaras (Hydrochaeris hydrochaeris) estão entre os principais hospedeiros do carrapato Amblyomma spp., o qual pode transmitir algumas espécies de riquétsias para seres humanos e animais. Como são frequentemente infestadas por carrapatos vetores potenciais, as capivaras podem ser usadas como sentinelas para riquetsioses, como a Febre Maculosa Brasileira. O objetivo do presente estudo foi determinar a soroprevalência de Rickettsia spp. por meio da reação de Imun (more) ofluorescência Indireta (RIFI) em 21 capivaras de vida livre e 10 capivaras de cativeiro do Zoológico do Refúgio Biológico Bela Vista, Itaipu Binacional, Foz do Iguaçu, Brasil. Antígenos de seis espécies de riquétsias já identi[1]icadas no Brasil (Rickettsia rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii e R. felis) foram utilizados para a RIFI. Carrapatos de cada capivara foram coletados para posterior identi[1]icação taxonômica. Um total de 19 (61,3%) amostras reagiu a pelo menos uma das espécies testadas. Foi encontrada soropositividade em 14 (45,2%), 12 (38,7%), 5 (16,1%), 4 (12,9%), 3 (9,7%) e 3 (9,7%) animais para R. rickettsii, R. bellii, R. parkeri, R. amblyommii, R. felis e R. rhipicephali, respectivamente. Duas capivaras de cativeiro apresentaram títulos sugestivos de infecção por R. rickettsii e uma amostra apresentou reação homóloga frente à R. parkeri. Apenas uma capivara de vida livre apresentou evidência de infecção por R. bellii. Os carrapatos coletados sobre as capivaras foram identificados como Amblyomma dubitatum e Amblyomma sp. Os resultados evidenciam a circulação de riquétsias na região, sugerindo uma potencial participação da capivara no ciclo de vida desta bactéria. Abstract in english Capybaras (Hydrochaeris hydrochaeris) are among the main hosts of Amblyomma spp. ticks, which is able to transmit Rickettsia species to human beings and animals. Since they are often infested with potential vector ticks, capybaras may be used as sentinels for rickettsiosis, such as the Brazilian Spotted Fever. The aim of the present study was to determine the prevalence of antibodies against Rickettsia spp. using the indirect immunofluorescence assay (IFA) in 21 free-rang (more) ing and 10 captive animals from the Zoological Park of the 'Bela Vista Biological Sanctuary' (BVBS), Itaipu Binational, Foz do Iguaçu, Southern Brazil. Antigens of six rickettsial species already identified in Brazil (Rickettsia rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii and R. felis) were used for IFA. Ticks from each capybara were collected for posterior taxonomic identification. A total of 19 (61.3%) samples reacted to at least one of tested species. Seropositivity was found in 14 (45.2%), 12 (38.7%), 5 (16.1%), 4 (12.9%), 3 (9.7%) and 3 (9.7%) animals for R. rickettsii, R. bellii, R. parkeri, R. amblyommii, R. felis and R. rhipicephali, respectively. Two captive capybaras presented suggestive titers of R. rickettsii infection and one sample showed homologous reaction to R. parkeri. Only one free-ranging capybara presented evidence R. bellii infection. Ticks collected on capybaras were identified as Amblyomma dubitatum e Amblyomma sp. Results evidenced the rickettsial circulation in the area, suggesting a potential role of capybaras on bacterial life cycle.

Fortes, Fernanda S.; Santos, Leonilda C.; Cubas, Zalmir S.; Barros-Filho, Ivan R.; Biondo, Alexander W.; Silveira, Iara; Labruna, Marcelo B.; Molento, Marcelo B.

2011-11-01

140

Anti-Rickettsia spp. antibodies in free-ranging and captive capybaras from southern Brazil Anticorpos anti-Rickettsia spp. em capivaras de vida livre e de cativeiro no Sul do Brasil  

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Full Text Available Capybaras (Hydrochaeris hydrochaeris) are among the main hosts of Amblyomma spp. ticks, which is able to transmit Rickettsia species to human beings and animals. Since they are often infested with potential vector ticks, capybaras may be used as sentinels for rickettsiosis, such as the Brazilian Spotted Fever. The aim of the present study was to determine the prevalence of antibodies against Rickettsia spp. using the indirect immunofluorescence assay (IFA) in 21 free-ranging and 10 captive animals from the Zoological Park of the 'Bela Vista Biological Sanctuary' (BVBS), Itaipu Binational, Foz do Iguaçu, Southern Brazil. Antigens of six rickettsial species already identified in Brazil (Rickettsia rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii and R. felis) were used for IFA. Ticks from each capybara were collected for posterior taxonomic identification. A total of 19 (61.3%) samples reacted to at least one of tested species. Seropositivity was found in 14 (45.2%), 12 (38.7%), 5 (16.1%), 4 (12.9%), 3 (9.7%) and 3 (9.7%) animals for R. rickettsii, R. bellii, R. parkeri, R. amblyommii, R. felis and R. rhipicephali, respectively. Two captive capybaras presented suggestive titers of R. rickettsii infection and one sample showed homologous reaction to R. parkeri. Only one free-ranging capybara presented evidence R. bellii infection. Ticks collected on capybaras were identified as Amblyomma dubitatum e Amblyomma sp. Results evidenced the rickettsial circulation in the area, suggesting a potential role of capybaras on bacterial life cycle.As capivaras (Hydrochaeris hydrochaeris) estão entre os principais hospedeiros do carrapato Amblyomma spp., o qual pode transmitir algumas espécies de riquétsias para seres humanos e animais. Como são frequentemente infestadas por carrapatos vetores potenciais, as capivaras podem ser usadas como sentinelas para riquetsioses, como a Febre Maculosa Brasileira. O objetivo do presente estudo foi determinar a soroprevalência de Rickettsia spp. por meio da reação de Imunofluorescência Indireta (RIFI) em 21 capivaras de vida livre e 10 capivaras de cativeiro do Zoológico do Refúgio Biológico Bela Vista, Itaipu Binacional, Foz do Iguaçu, Brasil. Antígenos de seis espécies de riquétsias já identi[1]icadas no Brasil (Rickettsia rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii e R. felis) foram utilizados para a RIFI. Carrapatos de cada capivara foram coletados para posterior identi[1]icação taxonômica. Um total de 19 (61,3%) amostras reagiu a pelo menos uma das espécies testadas. Foi encontrada soropositividade em 14 (45,2%), 12 (38,7%), 5 (16,1%), 4 (12,9%), 3 (9,7%) e 3 (9,7%) animais para R. rickettsii, R. bellii, R. parkeri, R. amblyommii, R. felis e R. rhipicephali, respectivamente. Duas capivaras de cativeiro apresentaram títulos sugestivos de infecção por R. rickettsii e uma amostra apresentou reação homóloga frente à R. parkeri. Apenas uma capivara de vida livre apresentou evidência de infecção por R. bellii. Os carrapatos coletados sobre as capivaras foram identificados como Amblyomma dubitatum e Amblyomma sp. Os resultados evidenciam a circulação de riquétsias na região, sugerindo uma potencial participação da capivara no ciclo de vida desta bactéria.

Fernanda S. Fortes; Leonilda C. Santos; Zalmir S. Cubas; Ivan R. Barros-Filho; Alexander W. Biondo; Iara Silveira; Marcelo B. Labruna; Marcelo B. Molento

2011-01-01

 
 
 
 
141

Serological Evidence for Exposure of Dogs to Rickettsia conorii, Rickettsia typhi, and Orientia tsutsugamushi in Sri Lanka.  

UK PubMed Central (United Kingdom)

Abstract Vector-borne rickettsial infection is a major cause of febrile illnesses throughout the world. Although vertebrates hosting the vectors play a vital role in the natural cycle of rickettsiae, studies have not been conducted on them in Sri Lanka. Therefore, the present study was designed to determine the exposure of dog population in Rajawatta, Thambavita, and areas of the Western Slopes and Unawatuna of Sri Lanka to rickettsial pathogens. A total of 123 dog blood samples were collected from those areas. Samples were tested for antibodies against Rickettsia conorii (RC) of the spotted fever group (SFG), Rickettsia typhi (RT) of the typhus group (TG), and Orientia tsutsugamushi (OT) of the scrub typhus group (ST) of rickettsiae by indirect immunofluorescence antibody test (IFA). Samples with titers ?1:64 were considered as positive in this study. Collectively, 49% dogs were found to have antibodies against the rickettsial agents. Of the dogs, 42%, 24%, and 2% had antibodies against RC, OT, and RT, respectively. The seropositive rate of 100% was observed in areas of the Western Slopes, whereas the lowest rate of 20% was in Unawatuna. Among the positive samples, antibody titers against RC and OT ranged from 1/64 to 1/8192. In contrast, the few dogs that tested positive for RT showed very low titers of 1/64 and 1/128. Results of this study show the extent of exposure to the pathogen and its dispersion in the natural ecology. We suggest that dogs could be acting as reservoirs in the rickettsial transmission cycle or could be effective tracer animals that can be used to detect areas with potential for future outbreaks.

Nanayakkara DM; Rajapakse RP; Wickramasinghe S; Kularatne SA

2013-08-01

142

Serological Evidence for Exposure of Dogs to Rickettsia conorii, Rickettsia typhi, and Orientia tsutsugamushi in Sri Lanka.  

Science.gov (United States)

Abstract Vector-borne rickettsial infection is a major cause of febrile illnesses throughout the world. Although vertebrates hosting the vectors play a vital role in the natural cycle of rickettsiae, studies have not been conducted on them in Sri Lanka. Therefore, the present study was designed to determine the exposure of dog population in Rajawatta, Thambavita, and areas of the Western Slopes and Unawatuna of Sri Lanka to rickettsial pathogens. A total of 123 dog blood samples were collected from those areas. Samples were tested for antibodies against Rickettsia conorii (RC) of the spotted fever group (SFG), Rickettsia typhi (RT) of the typhus group (TG), and Orientia tsutsugamushi (OT) of the scrub typhus group (ST) of rickettsiae by indirect immunofluorescence antibody test (IFA). Samples with titers ?1:64 were considered as positive in this study. Collectively, 49% dogs were found to have antibodies against the rickettsial agents. Of the dogs, 42%, 24%, and 2% had antibodies against RC, OT, and RT, respectively. The seropositive rate of 100% was observed in areas of the Western Slopes, whereas the lowest rate of 20% was in Unawatuna. Among the positive samples, antibody titers against RC and OT ranged from 1/64 to 1/8192. In contrast, the few dogs that tested positive for RT showed very low titers of 1/64 and 1/128. Results of this study show the extent of exposure to the pathogen and its dispersion in the natural ecology. We suggest that dogs could be acting as reservoirs in the rickettsial transmission cycle or could be effective tracer animals that can be used to detect areas with potential for future outbreaks. PMID:23930973

Nanayakkara, Devathri M; Rajapakse, R P V J; Wickramasinghe, Susiji; Kularatne, Senanayaka A M

2013-05-13

143

A novel fluorescent in situ hybridization technique for detection of Rickettsia spp. in archival samples.  

Science.gov (United States)

A novel, sensitive and specific method for detecting Rickettsia spp. in archival samples is described. The method involves the use of fluorescently marked oligonucleotide probes for in situ hybridization. Specific hybridization of Rickettsia was found without problems of cross-reactions with bacterial species shown to cross-react serologically. PMID:19007824

Svendsen, Claus Bo; Boye, Mette; Struve, Carsten; Krogfelt, Karen A

2008-11-05

144

Primary isolation of spotted fever group rickettsiae from Amblyomma cooperi collected from Hydrochaeris hydrochaeris in Brazil  

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Full Text Available This paper reports the first isolation of a spotted fever group rickettsia from an Amblyomma cooperi ixodid collected from a capybara (Hydrochaeris hydrochaeris) in an endemic area of spotted fever in the County of Pedreira, State of São Paulo, Brazil. Isolation was performed in Vero cell culture and submitted to immunofluorescence, using antibody from Rickettsia rickettsii-positive human serum.

Elba Regina Sampaio de Lemos; Heloísa Helena Barbosa Melles; Sílvia Colombo; Raimundo Diogo Machado; José Rodrigues Coura; Maria Angélica Arpon Guimarães; Selênio R Sanseverino; Aline Moura

1996-01-01

145

Identification and antigenic typing of Rickettsia tsutsugamushi in naturally infected chiggers (Acarina: Trombiculidae) by direct immunofluorescence.  

UK PubMed Central (United Kingdom)

Rickettsia tsutsugamushi organisms were detected and typed antigenically by direct immunofluorescence in mites from laboratory-maintained infected colonies of Leptotrombidium (Leptotrombidium) fletcheri and L. (L.) arenicola. Rickettsiae were identified most readily in unengorged larvae, but were also discernable in engorged larvae and all post-larval stages of the vectors.

Dohany AL; Shirai A; Robinson DM; Ram S; Huxsoll DL

1978-11-01

146

Molecular investigations of Rickettsia helvetica infection in dogs, foxes, humans and Ixodes ticks  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rickettsia helvetica, a tick-borne member of the spotted fever group Rickettsiae, is a suspected pathogen in humans; however its role in animals is unknown. The aims of this study were to establish a R. helvetica-specific real-time TaqMan PCR assay and apply it to the analysis of tick vectors (poten...

Boretti, F S; Perreten, A; Meli, M L; Cattori, V; Willi, B; Wengi, N; Hornok, S; Honegger, H; Hegglin, D; Woelfel, R; Reusch, C E

147

Serological evidence of typhus group Rickettsia in a homeless population: Houston, Texas  

Science.gov (United States)

Sera from 176 homeless people in Houston was tested for antibodies against typhus group rickettsiae (TGR). Sera from 19 homeless people were reactive to TGR antigens by ELISA and IFA. Two people had antibodies against Rickettsia prowazekii (epidemic typhus) and the remaining 17 had antibodies agains...

148

Typhus and typhuslike rickettsiae associated with opossums and their fleas in Los Angeles County, California.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The recent discovery of cat fleas (Ctenocephalides felis) infected with a typhuslike rickettsia (designated the ELB agent) raises the question of whether similar rickettsial infections exist in wild cat flea populations. We verified the presence of the ELB agent and Rickettsia typhi in urban and sub...

Williams, S G; Sacci, J B; Schriefer, M E; Andersen, E M; Fujioka, K K; Sorvillo, F J; Barr, A R; Azad, A F

149

Rickettsia felis from Cat Fleas: Isolation and Culture in a Tick-Derived Cell Line  

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Rickettsia felis, the etiologic agent of spotted fever, is maintained in cat fleas by vertical transmission and resembles other tick-borne spotted fever group rickettsiae. In the present study, we utilized an Ixodes scapularis-derived tick cell line, ISE6, to achieve isolation and propagation of R. ...

Pornwiroon, Walairat; Pourciau, Susan S.; Foil, Lane D.; Macaluso, Kevin R.

150

Human T Lymphocyte Recognition of Cyanogen Bromide Fragments of the Surface Protein of Rickettsia Typhi.  

Science.gov (United States)

Rickettsiae preferentially invade and grow in endothelial cells of blood vessels in vivo.1 Rickettsia typhi and R. prowazekii induce humoral and cell-mediated immune responses, although the role played in the clearance of the organisms by each of these re...

A. Churilla W. M. Ching G. A. Dasch M. Carl

1990-01-01

151

THE DISTRIBUTION OF RICKETTSIA IN THE TISSUES OF INSECTS AND ARACHNIDS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the absence of a satisfactory definition of Rickettsia the observations herein recorded were arbitrarily limited to bacterium-like organisms which are intracellular and Gram-negative. Rickettsia of this type were found in the following species: Amblyomma americana, Amblyomma hebræum, Boophilus d...

Cowdry, E. V.

152

Caracterização de Rickettsia spp. circulante em foco silencioso de febre maculosa brasileira no Município de Caratinga, Minas Gerais, Brasil/ Characterization of Rickettsia spp. circulating in a silent peri-urban focus for Brazilian spotted fever in Caratinga, Minas Gerais, Brazil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O objetivo deste trabalho foi caracterizar Rickettsia spp. circulante em artrópodes vetores no Município de Caratinga, Minas Gerais, Brasil, por meio da PCR, e investigar a presença de anticorpos para riquétsias do grupo da febre maculosa em cães e eqüinos. 2.610 ectoparasitos foram coletados e identificados taxonomicamente. Amostras de DNA obtidas desses vetores foram submetidas à PCR e seqüenciamento. Em pulgas do gênero Ctenocephalides e em carrapatos Amblyomm (more) a cajennense foram identificadas seqüências com 100% de homologia com R. felis. Em carrapatos Rhipicephalus sanguineus uma seqüência apresentou 99% de homologia com R. felis e uma seqüência obtida de A. cajennense apresentou 97% de homologia com R. honei e R. rickettsii. Soros de cães (73) e de eqüinos (18) foram submetidos à imunofluorescência indireta (RIFI) usando-se antígeno de R. rickettsii. Apenas três dos soros de eqüinos (17%) mostraram-se positivos. A detecção molecular de riquetsias potencialmente patogênicas ao homem em vetores e a presença de sororeatividade para riquetsias do grupo da febre maculosa em eqüinos, demonstram o risco de transmissão de riquetsioses nessa área e a necessidade de se manter um sistema contínuo de vigilância epidemiológica. Abstract in english The present study was intended to characterize Rickettsia spp. circulating in arthropod vectors in Caratinga, Minas Gerais, Brazil, by PCR and to investigate the presence of antibodies against the spotted fever Rickettsiae group (SFRG) in dogs and horses. 2,610 arthropods were collected and taxonomically identified. DNA samples obtained from these vectors were submitted to PCR and cycle-sequenced. Ctenocephalides and Amblyomma cajennense showed sequences presenting 100.0% (more) homology with R. felis. A sequence obtained from Rhipicephalus sanguineus showed 99.0% homology with R. felis, and a sequence from A. cajennense showed 97.0% homology with R. honei and R. rickettsii. Canine (73) and equine (18) serum samples were tested by indirect fluorescent antibody (IFA) using R. rickettsii antigen. Only three of the equine sera tested (17.0%) had positive antibody titers. Molecular detection of rickettsiae species potentially pathogenic to humans in arthropod vectors and the presence of seroreactivity to SFRG in horses show the risk of transmission of rickettsiosis in this area and the need to maintain continuous epidemiological surveillance for rickettsial diseases.

Cardoso, Luciane Daniele; Freitas, Renata Nascimento; Mafra, Cláudio Lísias; Neves, Cristiane Vilas Boas; Figueira, Fátima Cristina Bacellar; Labruna, Marcelo Bahia; Gennari, Solange M.; Walker, David Hughes; Galvão, Márcio Antônio Moreira

2006-03-01

153

Serological survey of Rickettsia sp. in horses and dogs in an non-endemic area in Brazil Identificação sorológica de Rickettsia sp. em equinos e cães de área não endêmica no Brasil  

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Full Text Available Brazilian Spotted Fever (BSF) is a lethal rickettsiosis in humans caused by the bacteria Rickettsia rickettsii, and is endemic in some areas of Brazil. Horses and dogs are part of the disease's life cycle and they may also serve as sentinel animals in epidemiological studies. The first human BSF case in the State of Paraná was reported in 2005. The present study was conducted in the municipality of Almirante Tamandaré, where no previous case of BSF was reported. Serum samples were collected from 71 horses and 20 dogs from nine properties in the area. Ticks were also collected from these animals. All farmers completed a questionnaire about their knowledge of BSF and animal health management. Serum samples were analyzed by indirect immunofluorescent-antibody assay (IFA) using R. rickettsii and R. parkeri as antigens. Ticks were analyzed by PCR for Rickettsia sp., and all of them were PCR-negative. Six horses (8.45%) and 4 dogs (20%) were identified as seropositive. Farmers were not aware of the correlation between the presence of ticks and risk of BSF. Although a non-endemic area, Almirante Tamandaré is a vulnerable environment for BSF and effective tick control measures are required.A Febre Maculosa Brasileira (FMB) é uma riquetsiose letal para humanos, causada pela bactéria Rickettsia rickettsii, e é endêmica em algumas regiões brasileiras. Equinos e cães podem participar do ciclo da doença e podem também servir como sentinelas em estudos epidemiológicos. O primeiro caso humano relatado no Estado do Paraná ocorreu em 2005. O presente estudo foi realizado no município de Almirante Tamandaré, região onde não há relatos de casos de FMB. Foram coletadas amostras de sangue de 71 cavalos e 20 cães em nove propriedades rurais na região. Carrapatos também foram colhidos dos animais. Todos os proprietários responderam a um questionário sobre o manejo sanitário dos animais e o conhecimento a respeito da FMB. As amostras de soro foram processadas pela técnica de Reação de Imunofluorescência Indireta (RIFI), utilizando-se os antígenos de R. rickettsii e R. parkeri. Os carrapatos foram analisados por PCR para Rickettsia sp. e todos foram negativos. Seis cavalos (8,45%) e 4 cães (20%) foram identificados como soropositivos. Todos os proprietários desconheciam a relação de carrapatos com a FMB. Embora considerada uma área não endêmica, Almirante Tamandaré é um ambiente vulnerável à FMB e um controle eficiente de carrapatos deve ser implementado.

Fernanda Gonçalves Batista; Daniella Matos da Silva; Kerriel Thandile Green; Louise Boulsfield de Lorenzi Tezza; Sâmara Pereira de Vasconcelos; Suelen Graziele Soares de Carvalho; Iara Silveira; Jonas Moraes-Filho; Marcelo Bahia Labruna; Fernanda Silva Fortes; Marcelo Beltrão Molento

2010-01-01

154

Caracterização de Rickettsia spp. circulante em foco silencioso de febre maculosa brasileira no Município de Caratinga, Minas Gerais, Brasil Characterization of Rickettsia spp. circulating in a silent peri-urban focus for Brazilian spotted fever in Caratinga, Minas Gerais, Brazil  

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Full Text Available O objetivo deste trabalho foi caracterizar Rickettsia spp. circulante em artrópodes vetores no Município de Caratinga, Minas Gerais, Brasil, por meio da PCR, e investigar a presença de anticorpos para riquétsias do grupo da febre maculosa em cães e eqüinos. 2.610 ectoparasitos foram coletados e identificados taxonomicamente. Amostras de DNA obtidas desses vetores foram submetidas à PCR e seqüenciamento. Em pulgas do gênero Ctenocephalides e em carrapatos Amblyomma cajennense foram identificadas seqüências com 100% de homologia com R. felis. Em carrapatos Rhipicephalus sanguineus uma seqüência apresentou 99% de homologia com R. felis e uma seqüência obtida de A. cajennense apresentou 97% de homologia com R. honei e R. rickettsii. Soros de cães (73) e de eqüinos (18) foram submetidos à imunofluorescência indireta (RIFI) usando-se antígeno de R. rickettsii. Apenas três dos soros de eqüinos (17%) mostraram-se positivos. A detecção molecular de riquetsias potencialmente patogênicas ao homem em vetores e a presença de sororeatividade para riquetsias do grupo da febre maculosa em eqüinos, demonstram o risco de transmissão de riquetsioses nessa área e a necessidade de se manter um sistema contínuo de vigilância epidemiológica.The present study was intended to characterize Rickettsia spp. circulating in arthropod vectors in Caratinga, Minas Gerais, Brazil, by PCR and to investigate the presence of antibodies against the spotted fever Rickettsiae group (SFRG) in dogs and horses. 2,610 arthropods were collected and taxonomically identified. DNA samples obtained from these vectors were submitted to PCR and cycle-sequenced. Ctenocephalides and Amblyomma cajennense showed sequences presenting 100.0% homology with R. felis. A sequence obtained from Rhipicephalus sanguineus showed 99.0% homology with R. felis, and a sequence from A. cajennense showed 97.0% homology with R. honei and R. rickettsii. Canine (73) and equine (18) serum samples were tested by indirect fluorescent antibody (IFA) using R. rickettsii antigen. Only three of the equine sera tested (17.0%) had positive antibody titers. Molecular detection of rickettsiae species potentially pathogenic to humans in arthropod vectors and the presence of seroreactivity to SFRG in horses show the risk of transmission of rickettsiosis in this area and the need to maintain continuous epidemiological surveillance for rickettsial diseases.

Luciane Daniele Cardoso; Renata Nascimento Freitas; Cláudio Lísias Mafra; Cristiane Vilas Boas Neves; Fátima Cristina Bacellar Figueira; Marcelo Bahia Labruna; Solange M. Gennari; David Hughes Walker; Márcio Antônio Moreira Galvão

2006-01-01

155

Spotted fever group rickettsia closely related to Rickettsia monacensis isolated from ticks in South Jeolla province, Korea.  

Science.gov (United States)

Rickettsia monacensis, a spotted fever group rickettsia, was isolated from Ixodes nipponensis ticks collected from live-captured small mammals in South Jeolla province, Korea in 2006. Homogenates of tick tissues were inoculated into L929 and Vero cell monolayers using shell vial assays. After several passages, Giemsa staining revealed rickettsia-like organisms in the inoculated Vero cells, but not the L929 cells. Sequencing analysis revealed that the ompA-small part (25-614?bp region), ompA-large part (2849-4455?bp region), nearly full-length ompB (58-4889?bp region) and gltA (196-1236?bp region) of the isolates had similarities of 100%, 99.8%, 99.3% and 99.5%, respectively, to those of R. monacensis. Furthermore, phylogenetic analysis showed that the isolate was grouped into the cluster in the same way as R. monacensis in the trees of all genes examined. These results strongly suggest that the isolate is closely related to R. monacensis. As far as is known, this is the first report of isolation of R. monacensis from ticks in Korea. PMID:23621111

Lee, Kyung-Min; Choi, Yeon-Joo; Shin, Sun-Hye; Choi, Min-Kyung; Song, Hyeon-Je; Kim, Heung-Chul; Klein, Terry A; Richards, Allen L; Park, Kyung-Hee; Jang, Won-Jong

2013-07-01

156

Spotted fever group rickettsia closely related to Rickettsia monacensis isolated from ticks in South Jeolla province, Korea.  

UK PubMed Central (United Kingdom)

Rickettsia monacensis, a spotted fever group rickettsia, was isolated from Ixodes nipponensis ticks collected from live-captured small mammals in South Jeolla province, Korea in 2006. Homogenates of tick tissues were inoculated into L929 and Vero cell monolayers using shell vial assays. After several passages, Giemsa staining revealed rickettsia-like organisms in the inoculated Vero cells, but not the L929 cells. Sequencing analysis revealed that the ompA-small part (25-614?bp region), ompA-large part (2849-4455?bp region), nearly full-length ompB (58-4889?bp region) and gltA (196-1236?bp region) of the isolates had similarities of 100%, 99.8%, 99.3% and 99.5%, respectively, to those of R. monacensis. Furthermore, phylogenetic analysis showed that the isolate was grouped into the cluster in the same way as R. monacensis in the trees of all genes examined. These results strongly suggest that the isolate is closely related to R. monacensis. As far as is known, this is the first report of isolation of R. monacensis from ticks in Korea.

Lee KM; Choi YJ; Shin SH; Choi MK; Song HJ; Kim HC; Klein TA; Richards AL; Park KH; Jang WJ

2013-07-01

157

Study on tick-borne rickettsiae in eastern Poland. I. Prevalence in Dermacentor reticulatus (Acari: Amblyommidae).  

UK PubMed Central (United Kingdom)

Rickettsia spp. transmitted by ticks are classified mostly in the Spotted Fever Group Rickettsiae (SFGR). Numerous species of this group have been identified in Eurasia as emerging pathogens, but still little is known about their occurrence, effects on human health, and co-incidence with other tick-borne pathogens. The aim of the presented study was to determine the prevalence of Rickettsia spp. in adult Dermacentor reticulatus (Acari: Amblyommidae) ticks collected in Lublin province of eastern Poland using the PCR method. The infection rate of D. reticulatus with Rickettsia spp. was 53.0%. All except one rickettsial isolates showed 100% homology with Rickettsia raoultii. A high prevalence of R. raoultii in Dermacentor reticulatus ticks from eastern Poland suggests that the SFGR species should be considered as potential causative agents of tick-borne diseases in this area.

Wójcik-Fatla A; Cisak E; Zaj?c V; Sroka J; Sawczyn A; Dutkiewicz J

2013-01-01

158

Effects of dorsal root ganglion destruction by adriamycin in patients with postherpetic neuralgia/ Efeitos da destruição da raiz dorsal ganglionar pela adriamicina em pacientes com neuralgia pós-herpética  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese OBJETIVO: Investigar os efeitos da destruição da raiz dorsal ganglionar em pacientes com neuralgia pós-herpética. MÉTODOS: Setenta e dois pacientes selecionados com neuralgia pós-herpética foram randomicamente distribuídos em dois grupos (n=36). Grupo A foi o grupo controle (tratado por injeção) e o grupo B foi o grupo com destruição da raiz dorsal do gânglio pela adriamicina. Os escores da Escala Analógica Visual (VAS), SAS, SF-MPQ escores, efeitos clínico (more) s e segurança terapêutica foram avaliados as antes da terapia, uma semana, três e seis meses após a terapia. Quarenta e quatro pacientes foram avaliados pela análise de intenção-em-tratar. RESULTADOS: A média dos escores de dor na escala de Likert foi significativamente reduzida em cada ponto no grupo B. Pacientes no grupo B relataram efetividade clínica aos seis meses com excelente resposta (16), boa resposta (12), melhora mais insatisfatória ou sem modificações (8). Escores VAS a cada tempo após o procedimento foram melhores em comparação ao pré-operatório. No grupo A não foi observada diferença significativa. Pacientes mostraram melhora nos escores de dormir no grupo B. Houve diferença significante no T2 no grupo A que T1. Não houve diferença significante no grupo A nos tempos T3 e T4 após a cirurgia em relação a antes. Comparação entre os grupos: houve diferença significante entre os grupos A e B a cada tempo após a cirurgia. CONCLUSÕES: A destruição da raiz dorsal ganglionar pela adriamicina sob perspectiva guiada pelo C-arm, a cirurgia pontual foi acurada sem qualquer reação adversa ou complicação séria, que pode efetivamente aliviar a dor em pacientes com neuralgia pós-herpética, mas os efeitos de longo prazo necessitam mais estudos. Abstract in english PURPOSE: To investigate the effects of dorsal root ganglion destruction in patients with postherpetic neuralgia (PHN). METHODS: Seventy-two patients with PHN selected were randomly divided into two groups (n=36). Group A was the control group (treated by injection) and group B was the group of dorsal root ganglion destruction by adriamycin. Visual analog scale scores (VAS), SAS, SF-MPQ scores. Clinical effects and therapy safety were evaluated before therapy, one week, th (more) ree and six months after therapy. Forty-four patients were available for intention-to-treat analysis. RESULTS: The average pain scores on the Likert scale were significantly reduced at each point in group B. Patients in group B reported clinical effectiveness at six months as excellent response, good response, improved but unsatisfactory or unchanged 16, 12 and 8.VAS scores at each time point after the operation were lower than that before operation and in group A, there was significant difference. Patients showed significant improvement in sleep scores in group B. There was significant difference at T2 in group A than T1. There was no significant difference in group A at T3, T4 after the operation than that before operation. Between group comparison: there was significant difference between group A and group B at each time point after the operation. CONCLUSIONS: Dorsal root ganglion destruction by adriamycin under guidance of C-arm perspective, the puncture operation was accurate without any adverse reaction or serious complications, which could effectively relieve pain of patients with postherpetic neuralgia, but the long-term effects needed further study.

Chun-jing, He; yi-ran, Luo; hao-xiong, Nie

2012-06-01

159

Effects of dorsal root ganglion destruction by adriamycin in patients with postherpetic neuralgia Efeitos da destruição da raiz dorsal ganglionar pela adriamicina em pacientes com neuralgia pós-herpética  

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Full Text Available PURPOSE: To investigate the effects of dorsal root ganglion destruction in patients with postherpetic neuralgia (PHN). METHODS: Seventy-two patients with PHN selected were randomly divided into two groups (n=36). Group A was the control group (treated by injection) and group B was the group of dorsal root ganglion destruction by adriamycin. Visual analog scale scores (VAS), SAS, SF-MPQ scores. Clinical effects and therapy safety were evaluated before therapy, one week, three and six months after therapy. Forty-four patients were available for intention-to-treat analysis. RESULTS: The average pain scores on the Likert scale were significantly reduced at each point in group B. Patients in group B reported clinical effectiveness at six months as excellent response, good response, improved but unsatisfactory or unchanged 16, 12 and 8.VAS scores at each time point after the operation were lower than that before operation and in group A, there was significant difference. Patients showed significant improvement in sleep scores in group B. There was significant difference at T2 in group A than T1. There was no significant difference in group A at T3, T4 after the operation than that before operation. Between group comparison: there was significant difference between group A and group B at each time point after the operation. CONCLUSIONS: Dorsal root ganglion destruction by adriamycin under guidance of C-arm perspective, the puncture operation was accurate without any adverse reaction or serious complications, which could effectively relieve pain of patients with postherpetic neuralgia, but the long-term effects needed further study.OBJETIVO: Investigar os efeitos da destruição da raiz dorsal ganglionar em pacientes com neuralgia pós-herpética. MÉTODOS: Setenta e dois pacientes selecionados com neuralgia pós-herpética foram randomicamente distribuídos em dois grupos (n=36). Grupo A foi o grupo controle (tratado por injeção) e o grupo B foi o grupo com destruição da raiz dorsal do gânglio pela adriamicina. Os escores da Escala Analógica Visual (VAS), SAS, SF-MPQ escores, efeitos clínicos e segurança terapêutica foram avaliados as antes da terapia, uma semana, três e seis meses após a terapia. Quarenta e quatro pacientes foram avaliados pela análise de intenção-em-tratar. RESULTADOS: A média dos escores de dor na escala de Likert foi significativamente reduzida em cada ponto no grupo B. Pacientes no grupo B relataram efetividade clínica aos seis meses com excelente resposta (16), boa resposta (12), melhora mais insatisfatória ou sem modificações (8). Escores VAS a cada tempo após o procedimento foram melhores em comparação ao pré-operatório. No grupo A não foi observada diferença significativa. Pacientes mostraram melhora nos escores de dormir no grupo B. Houve diferença significante no T2 no grupo A que T1. Não houve diferença significante no grupo A nos tempos T3 e T4 após a cirurgia em relação a antes. Comparação entre os grupos: houve diferença significante entre os grupos A e B a cada tempo após a cirurgia. CONCLUSÕES: A destruição da raiz dorsal ganglionar pela adriamicina sob perspectiva guiada pelo C-arm, a cirurgia pontual foi acurada sem qualquer reação adversa ou complicação séria, que pode efetivamente aliviar a dor em pacientes com neuralgia pós-herpética, mas os efeitos de longo prazo necessitam mais estudos.

He Chun-jing; Luo yi-ran; Nie hao-xiong

2012-01-01

160

Changes in immunoferritin labeling of Rickettsia tsutsugamushi after serial cultivation in 60Co-irradiated BHK cells  

International Nuclear Information System (INIS)

The immunolabeling characteritics of Rickettsia tsutsugamushi (Gilliam strain) were examined by using a purified immunoglobulin G fraction of antibody to R. tsutsugamushi raised in rabbits. When rickettsiae in BHK-21 cells infected from yolk sac seed material were immunoferritin labeled, the binding of ferritin was found to be dense and uniform on the outer surface of the rickettsiae in disrupted host cells. Immunolabeling of purified suspensions of extracellular rickettsiae resulted in the uniform ferritin labeling of the microorganism. The immunoferritin labeling of R. tsutsugamushi during successive serial passages in BHK-21 cells revealed decreased labeling with each passage, and by the 10th passage there was no detectable labeling. However, these rickettsiae inoculated back into yolk sacs regained their immunoferritin labeling. Antibody against rickettsiae cultivated in BHK-21 cells continued labeling rickettsiae even after 9 serial passages in BHK-21 cells.

1979-01-01

 
 
 
 
161

Resultados comparativos de la disección ganglionar en cáncer de recto con y sin tratamiento previo del tejido adiposo Comparative results of ganglion dissection in cancer of the rectum with and without prior treatment with adipose tissue  

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Full Text Available Fundamento. El propósito de este estudio es describir los resultados obtenidos mediante dos técnicas de aislamiento de ganglios linfáticos en piezas quirúrgicas de resección anterior por adenocarcinoma de recto. Material y métodos. En una serie de 30 casos consecutivos de pacientes intervenidos por adenocarcinoma de recto hemos realizado una búsqueda de ganglios de forma manual convencional y una segunda tras 24 horas en una solución desengrasante a temperatura ambiente. Resultados. En la primera búsqueda se han aislado 335 ganglios linfáticos con una media que oscila entre 6,46 y 17,58, correspondiendo los valores más bajos a los grupos que habían recibido tratamiento adyuvante previo. En la segunda inclusión, tras la acción de la solución de aclaramiento hemos encontrado nuevos ganglios (85) en un 70% de los casos, en número y tamaño sensiblemente inferior al inicial. Conclusiones. La disección ganglionar manual del tejido adiposo es un método fiable para el aislamiento de ganglios linfáticos en las piezas de resección por adenocarcinoma de recto. La búsqueda de ganglios linfáticos tras la acción de una solución de aclaramiento debe reservarse para los casos en los que no se alcanza el mínimo aconsejado en el estadiaje TNM.Background. The aim of this study is to describe the result obtained through two techniques of isolation of lymphatic lymph nodes in surgical pieces of anterior resection due to adenocarcinoma of the rectum. Material and methods. We carried out a search in a series of 30 consecutive cases of patients operated on for adenocarcinoma of the rectum for lymph nodes first in a manual conventional way and second after 24 hours in a degreasing solution at room temperature. Results. In the first search 335 lymph nodes were lymph nodes isolated, with an average that oscillated between 6.46 and 17.58, with the lower values corresponding to the groups that had received prior adjuvant treatment. In the second inclusion, following the action of the clearing solution, we found new lymph nodes (85) in some 75% of the cases, appreciably lower in number and smaller in size than the initial search. Conclusions. Manual lymph nodes dissection of the adipose tissue is a reliable method for the isolation of lymphatic lymph nodes in pieces of resection due to adenocarcinoma of the rectum. The search for lymphatic ganglions following the action of a clearing solution should be reserved for cases in which the minimum recommended in the TNM staging is not reached.

I. Amat; R. Beloqui; P. de Llano; M. Gómez-Dorronsoro; B. Larrínaga; A. Córdoba; F. Pérez

2003-01-01

162

Sca1, a previously undescribed paralog from autotransporter protein-encoding genes in Rickettsia species  

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Full Text Available Abstract Background Among the 17 genes encoding autotransporter proteins of the "surface cell antigen" (sca) family in the currently sequenced Rickettsia genomes, ompA, sca5 (ompB) and sca4 (gene D), have been extensively used for identification and phylogenetic purposes for Rickettsia species. However, none of these genes is present in all 20 currently validated Rickettsia species. Of the remaining 14 sca genes, sca1 is the only gene to be present in all nine sequenced Rickettsia genomes. To estimate whether the sca1 gene is present in all Rickettsia species and its usefulness as an identification and phylogenetic tool, we searched for sca1genes in the four published Rickettsia genomes and amplified and sequenced this gene in the remaining 16 validated Rickettsia species. Results Sca1 is the only one of the 17 rickettsial sca genes present in all 20 Rickettsia species. R. prowazekii and R. canadensis exhibit a split sca1 gene whereas the remaining species have a complete gene. Within the sca1 gene, we identified a 488-bp variable sequence fragment that can be amplified using a pair of conserved primers. Sequences of this fragment are specific for each Rickettsia species. The phylogenetic organization of Rickettsia species inferred from the comparison of sca1 sequences strengthens the classification based on the housekeeping gene gltA and is similar to those obtained from the analyses of ompA, sca5 and sca4, thus suggesting similar evolutionary constraints. We also observed that Sca1 protein sequences have evolved under a dual selection pressure: with the exception of typhus group rickettsiae, the amino-terminal part of the protein that encompasses the predicted passenger domain, has evolved under positive selection in rickettsiae. This suggests that the Sca1 protein interacts with the host. In contrast, the C-terminal portion containing the autotransporter domain has evolved under purifying selection. In addition, sca1 is transcribed in R. conorii, and might therefore be functional in this species. Conclusion The sca1 gene, encoding an autotransporter protein that evolves under dual evolution pressure, is the only sca-family gene to be conserved by all Rickettsia species. As such, it is a valuable identification target for these bacteria, especially because rickettsial isolates can be identified by amplification and sequencing of a discriminatory gene fragment using a single primer pair. It may also be used as a phylogenetic tool. However, its current functional status remains to be determined although it was found expressed in R. conorii.

Ngwamidiba Maxime; Blanc Guillaume; Raoult Didier; Fournier Pierre-Edouard

2006-01-01

163

Gene gain and loss events in Rickettsia and Orientia species  

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Full Text Available Abstract Background Genome degradation is an ongoing process in all members of the Rickettsiales order, which makes these bacterial species an excellent model for studying reductive evolution through interspecies variation in genome size and gene content. In this study, we evaluated the degree to which gene loss shaped the content of some Rickettsiales genomes. We shed light on the role played by horizontal gene transfers in the genome evolution of Rickettsiales. Results Our phylogenomic tree, based on whole-genome content, presented a topology distinct from that of the whole core gene concatenated phylogenetic tree, suggesting that the gene repertoires involved have different evolutionary histories. Indeed, we present evidence for 3 possible horizontal gene transfer events from various organisms to Orientia and 6 to Rickettsia spp., while we also identified 3 possible horizontal gene transfer events from Rickettsia and Orientia to other bacteria. We found 17 putative genes in Rickettsia spp. that are probably the result of de novo gene creation; 2 of these genes appear to be functional. On the basis of these results, we were able to reconstruct the gene repertoires of "proto-Rickettsiales" and "proto-Rickettsiaceae", which correspond to the ancestors of Rickettsiales and Rickettsiaceae, respectively. Finally, we found that 2,135 genes were lost during the evolution of the Rickettsiaceae to an intracellular lifestyle. Conclusions Our phylogenetic analysis allowed us to track the gene gain and loss events occurring in bacterial genomes during their evolution from a free-living to an intracellular lifestyle. We have shown that the primary mechanism of evolution and specialization in strictly intracellular bacteria is gene loss. Despite the intracellular habitat, we found several horizontal gene transfers between Rickettsiales species and various prokaryotic, viral and eukaryotic species. Open peer review Reviewed by Arcady Mushegian, Eugene V. Koonin and Patrick Forterre. For the full reviews please go to the Reviewers' comments section.

Georgiades Kalliopi; Merhej Vicky; El Karkouri Khalid; Raoult Didier; Pontarotti Pierre

2011-01-01

164

[Rickettsia conorii infection in Romania, 2000-2008].  

UK PubMed Central (United Kingdom)

OBJECTIVES: presenting the epidemiological aspects of Rickettsia conorii infection in Romania between 2000-2008. METHODS: A descriptive epidemiology study of Rickettsia conorii infection cases noticed in Romania between 2000-2008, which provide data regarding: time, place a4d person. The study also presents some risk factors. RESULTS: All cases were sporadic and were noticed in southern Romania. The highest incidence was registered in 2001 in Constanta district (44.2% per ten thousand inhabitants). The majority of cases were registred between April-November with a maximum of cases in August (38%) The patients were mainly from urban areas (80%); The more affected age group was 45-54 year (25%). The most predominant clinical expression was the medium one (58% of cases). In 99% of the cases, the release status from the hospital was cured and the evolution of the illness was favorable. In this period were just 2 deceased In 96% of the confirmed cases the tick exposure has appeared within the contact with parasited animals and took place in 60% of cases at home. 4% of the cases recognaised a professional contact with parasitated animals. In 93% of the cases the reservoir was represented by the parasitated dog. CONCLUSION: The sporadic evolution of the cases demonstrated that the natural focality of the disease in Romania persists, the distribution of cases matches with that of Rickettsia conorii and its tick vectors and also with the period of greatest activity of the vector (Rhipicephalus sanguineous, specific for dogs). The disease clearly represents a public health problem whose magnitude is not known.

Serban R; Pistol A; Negu? M; Cucuiu R

2009-10-01

165

Radioiodination of an outer membrane protein in intact Rickettsia prowazekii  

International Nuclear Information System (INIS)

Intact Rickettsia prowazekii was radiolabeled with the glucose oxidase-lactoperoxidase method of iodination. Separation of the rickettsial extract into cytoplasmic, outer and inner membrane fractions demonstrated that the outer membrane was preferentially labeled. Analysis of the polypeptides of these fractions on high-resolution slab polyacrylamide gels showed that most of the 125I was in polypeptide T49, an outer membrane constituent. Additional outer membrane polypeptides were iodinated in broken envelope preparations, demonstrating that T49 is uniquely accessible to the external environment and the asymmetric polypeptide organization of the outer membrane.

1980-01-01

166

Horizontal transmission of the insect symbiont Rickettsia is plant-mediated  

Science.gov (United States)

Bacteria in the genus Rickettsia, best known as vertebrate pathogens vectored by blood-feeding arthropods, can also be found in phytophagous insects. The presence of closely related bacterial symbionts in evolutionarily distant arthropod hosts presupposes a means of horizontal transmission, but no mechanism for this transmission has been described. Using a combination of experiments with live insects, molecular analyses and microscopy, we found that Rickettsia were transferred from an insect host (the whitefly Bemisia tabaci) to a plant, moved inside the phloem, and could be acquired by other whiteflies. In one experiment, Rickettsia was transferred from the whitefly host to leaves of cotton, basil and black nightshade, where the bacteria were restricted to the phloem cells of the plant. In another experiment, Rickettsia-free adult whiteflies, physically segregated but sharing a cotton leaf with Rickettsia-plus individuals, acquired the Rickettsia at a high rate. Plants can serve as a reservoir for horizontal transmission of Rickettsia, a mechanism which may explain the occurrence of phylogenetically similar symbionts among unrelated phytophagous insect species. This plant-mediated transmission route may also exist in other insect–symbiont systems and, since symbionts may play a critical role in the ecology and evolution of their hosts, serve as an immediate and powerful tool for accelerated evolution.

Caspi-Fluger, Ayelet; Inbar, Moshe; Mozes-Daube, Netta; Katzir, Nurit; Portnoy, Vitaly; Belausov, Eduard; Hunter, Martha S.; Zchori-Fein, Einat

2012-01-01

167

Horizontal transmission of the insect symbiont Rickettsia is plant-mediated.  

UK PubMed Central (United Kingdom)

Bacteria in the genus Rickettsia, best known as vertebrate pathogens vectored by blood-feeding arthropods, can also be found in phytophagous insects. The presence of closely related bacterial symbionts in evolutionarily distant arthropod hosts presupposes a means of horizontal transmission, but no mechanism for this transmission has been described. Using a combination of experiments with live insects, molecular analyses and microscopy, we found that Rickettsia were transferred from an insect host (the whitefly Bemisia tabaci) to a plant, moved inside the phloem, and could be acquired by other whiteflies. In one experiment, Rickettsia was transferred from the whitefly host to leaves of cotton, basil and black nightshade, where the bacteria were restricted to the phloem cells of the plant. In another experiment, Rickettsia-free adult whiteflies, physically segregated but sharing a cotton leaf with Rickettsia-plus individuals, acquired the Rickettsia at a high rate. Plants can serve as a reservoir for horizontal transmission of Rickettsia, a mechanism which may explain the occurrence of phylogenetically similar symbionts among unrelated phytophagous insect species. This plant-mediated transmission route may also exist in other insect-symbiont systems and, since symbionts may play a critical role in the ecology and evolution of their hosts, serve as an immediate and powerful tool for accelerated evolution.

Caspi-Fluger A; Inbar M; Mozes-Daube N; Katzir N; Portnoy V; Belausov E; Hunter MS; Zchori-Fein E

2012-05-01

168

Study of the density of ganglion cells in the terminal bowel of rats with anorectal malformations Estudo da densidade das células ganglionares no intestino terminal de ratos portadores de anomalia anorretal  

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Full Text Available PURPOSE: To study the ganglion cells (GC) in the terminal bowel of rats with ethylenethiourea (ETU) induced anorectal malformations (ARM). METHODS: The animals were divided into three groups: Group A - normal fetuses from pregnant rats that were not administered ETU; Group B - fetuses without ARM born from pregnant rats that were administered ETU and Group C - fetuses with ARM born from pregnant rats that received ETU. ETU was administered on the 11th day of pregnancy at the dose of 125 mg/kg body weight by gastric gavage. The rats had cesarean section on the 21st day of gestation. The fetuses’ terminal bowel tissue was analyzed by immunohistochemistry to demonstrate ganglion cells. RESULTS: Statistically significant differences were found between groups A, B and C regarding ganglion cell densities. Group A had the highest cell density, followed by Group B and the lowest density was found in Group C. CONCLUSION: Ganglion cell densities are decreased in the terminal bowel of rats with ARM.OBJETIVO: Estudar as células ganglionares (CG) no intestino terminal de ratos portadores de anomalia anorretal (AAR) induzida pela etilenotiouréia (ETU). MÉTODOS: Os animais foram distribuídos em três grupos: Grupo A - fetos normais, obtidos de ratas grávidas às quais não foi administrada ETU; Grupo B - fetos não portadores de AAR obtidos de ratas grávidas às quais foi administrada ETU e Grupo C - fetos portadores de AAR obtidos de ratas grávidas às quais foi administrada ETU. A ETU foi administrada no décimo primeiro dia de gestação na dose de 125 mg/Kg, por gavagem. As ratas foram submetidas à laparotomia e histerotomia para retirada dos fetos no vigésimo primeiro dia de gestação. O intestino terminal dos fetos foi retirado e analisado por imunohistoquímica para pesquisa de CG. RESULTADOS: Foram encontradas diferenças estatisticamente significantes entre os grupos A, B e C quanto à densidade de CG. O grupo A apresentou a maior densidade, seguida pelo grupo B, e a menor densidade foi encontrada no Grupo C. CONCLUSÃO: Existe uma menor densidade de CG no intestino terminal de ratos portadores de AAR.

Maurício Macedo; José Luiz Martins; Karine Furtado Meyer; Iberê Cauduro Soares

2007-01-01

169

Coexistência de linfadenite axilar tuberculosa e metástase ganglionar de carcinoma lobular de mama: relato de um caso/ Coexistence of axillary tuberculous lymphadenitis and ganglionic metastasis in mammary lobular carcinoma: a case report  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Relato do caso de uma mulher com 83 anos apresentando nódulo e retração de pele na mama direita com oito meses de evolução. Ao exame físico verificou-se nódulo sólido de 5 cm, localizado no quadrante súpero-lateral de mama direita, associado a presença de retração de pele correspondente e linfonodos axilares não coalescentes ipsilaterais. O resultado da mamografia evidenciou nódulo de 4 cm de diâmetro irregular no quadrante súpero-lateral da mama direita ( (more) bi-rads V). Estádio clínico: T2N1M0 (IIB). O tratamento cirúrgico incluiu mastectomia radical modificada (à Maden) com dissecção axilar níveis I, II e III. Avaliação histopatológica demonstrou a presença de carcinoma lobular infiltrativo que mediu 2,5 cm (T2), presença de linfadenite granulomatosa causada por tuberculose em linfonodos dos níveis I, II e III, associados a metástase de carcinoma lobular em um único nível linfático, nível I. Estádio patológico: pT2pN1aM0. A paciente recebeu tratamento para tuberculose ganglionar com rifampicina, isoniazida e pirazinamida por um ano. Foram solicitados receptores hormonais, os quais mostraram-se positivos, sendo feito terapia adjuvante com tamoxifeno. Durante o primeiro ano de seguimento a paciente evoluiu bem, sem sinais de recidiva local ou metástases a distância. Abstract in english Report of a case of an 83-year-old woman presenting a nodule and skin retraction in the right breast for eight months. On physical examination, a solid nodule of 5 cm was observed, located in the upper-lateral quadrant of the right breast, associated with skin retraction and ipsilateral lymph nodes. Mammographic findings showed irregularly limited nodules of 4 cm in the upper-lateral quadrant of the right breast (bi-rads V). Clinical staging: T2N1M0 (IIB). Surgical treatm (more) ent included a modified radical mastectomy with axillary dissection levels I, II, and III. Histopathologic evaluation demonstrated the presence of an infiltrating lobular carcinoma measuring 2.5 cm (T2), presence of granulomatous lymphadenitis caused by tuberculosis in level I, II, and III lymph nodes, associated with lobular carcinoma metastasis in a single level I lymph node. Pathologic staging: pT2pN1aM0. The treatment for the axillary tuberculous lymphadenitis was done with rifampin, isoniazid and pyrazinamide for one year. Hormone receptors were positive, and adjuvant therapy was initiated with tamoxifen. During the first year of follow-up the patient had no signal of local recurrence or distant metastases.

Linhares, José Juvenal; Millen, Eduardo Camargo; Antonini, Marcelo; Fagundes, Pedro César; Falcão, Pedro Gustavo; Araújo Neto, Joaquim Teodoro de

2005-07-01

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Genome sequence of the endosymbiont Rickettsia peacockii and comparison with virulent Rickettsia rickettsii: identification of virulence factors.  

UK PubMed Central (United Kingdom)

Rickettsia peacockii, also known as the East Side Agent, is a non-pathogenic obligate intracellular bacterium found as an endosymbiont in Dermacentor andersoni ticks in the western USA and Canada. Its presence in ticks is correlated with reduced prevalence of Rickettsia rickettsii, the agent of Rocky Mountain Spotted Fever. It has been proposed that a virulent SFG rickettsia underwent changes to become the East Side Agent. We determined the genome sequence of R. peacockii and provide a comparison to a closely related virulent R. rickettsii. The presence of 42 chromosomal copies of the ISRpe1 transposon in the genome of R. peacockii is associated with a lack of synteny with the genome of R. rickettsii and numerous deletions via recombination between transposon copies. The plasmid contains a number of genes from distantly related organisms, such as part of the glycosylation island of Pseudomonas aeruginosa. Genes deleted or mutated in R. peacockii which may relate to loss of virulence include those coding for an ankyrin repeat containing protein, DsbA, RickA, protease II, OmpA, ScaI, and a putative phosphoethanolamine transferase. The gene coding for the ankyrin repeat containing protein is especially implicated as it is mutated in R. rickettsii strain Iowa, which has attenuated virulence. Presence of numerous copies of the ISRpe1 transposon, likely acquired by lateral transfer from a Cardinium species, are associated with extensive genomic reorganization and deletions. The deletion and mutation of genes possibly involved in loss of virulence have been identified by this genomic comparison. It also illustrates that the introduction of a transposon into the genome can have varied effects; either correlating with an increase in pathogenicity as in Francisella tularensis or a loss of pathogenicity as in R. peacockii and the recombination enabled by multiple transposon copies can cause significant deletions in some genomes while not in others.

Felsheim RF; Kurtti TJ; Munderloh UG

2009-01-01

171

Survey of rickettsiae in humans, dogs, horses, and ticks in Northern Paraná, BrazilLevantamento de riquétsias em humanos, cães, cavalos e carrapatos no Norte do Paraná, Brasil  

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Full Text Available Brazilian Spotted Fever is a disease caused by Rickettsia rickettsii, and is transmitted to humans and animals by Amblyomma spp. The objective of this work was to study the epidemiology of spotted fever group rickettsiae in rural areas of Northern Parana. In Alvorada do Sul municipality, 88 humans, 83 dogs, and 18 horses were sampled, and in Arapongas municipality, 138 humans, 90 dogs and 18 horses were studied. All the sera were tested by IFA in which R. rickettsii and R. parkeri were used as antigens, considering titers ? 64 positive. Ticks collected from dogs and horses were tested by PCR. In Alvorada do Sul, 24% and 16.1% of humans, 55.6% and 22.2% of horses and, 22.9% and 18.1% of dogs were seropositive for R rickettsii and R. parkeri, respectively. In Arapongas, 9.4% and 4.3% of the humans, 5.6% and 5.6% of horses and, 13.3% and 12.2% of the dogs were seropositive for R. rickettsii and R. parkeri, respectively. PCR detected seven ticks with gltA sequences that showed similarity with R. bellii. The presence of antibodies to R. parkeri and R. rickettsii in dogs, horses and humans demonstrates a potential risk for spotted fever group rickettsiae in these areas.Febre Maculosa Brasileira é uma doença causada por Rickettsia rickettsii, e é transmitida para humanos e animais por Amblyomma spp. O objetivo deste trabalho foi estudar a epidemiologia de riquétsias do grupo da febre em áreas rurais do Norte do Paraná. No município de Alvorada do Sul, 88 pessoas, 83 cães e 18 cavalos foram amostrados, e no município de Arapongas, 138 seres humanos, 90 cães e 18 cavalos foram estudados. Todos os soros foram testados por IFI com R. rickettsii e R. parkeri como antígenos, considerando-se os títulos ? 64 positivos. Carrapatos coletados de cães e cavalos foram testados por PCR. Em Alvorada do Sul, 24% e 16,1% dos seres humanos, 55,6% e 22,2% de cavalos e, 22,9% e 18,1% de cães foram soropositivos para R. rickettsii e R. parkeri, respectivamente. Em Arapongas, 9,4% e 4,3% dos seres humanos, 5,6% e 5,6% de cavalos e, 13,3% e 12,2% dos cães foram soropositivos para R. rickettsii e R. parkeri, respectivamente. A PCR detectou 7 carrapatos com seqüências gltA que mostrou semelhança com R. bellii. A presença de anticorpos para R. rickettsii e R. parkeri em cães, cavalos e seres humanos demonstra um risco potencial para riquétsias do grupo da febre maculosa nestas áreas.

Katia Tamekuni; Roberta dos Santos Toledo; Mauro de Freitas Silva Filho; Valeska Bender Haydu; Richard Campos Pacheco; Marcelo Bahia Labruna; John Stephen Dumler; Odilon Vidotto

2011-01-01

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An update on the detection and treatment of Rickettsia felis  

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Full Text Available Laya Hun, Adriana TroyoCentro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa RicaAbstract: Rickettsia felis was described as a human pathogen almost two decades ago, and human infection is currently reported in 18 countries in all continents. The distribution of this species is worldwide, determined by the presence of the main arthropod vector, Ctenocephalides felis (Bouché). The list of symptoms, which includes fever, headache, myalgia, and rash, keeps increasing as new cases with unexpected symptoms are described. Moreover, the clinical presentation of R. felis infection can be easily confused with many tropical and nontropical diseases, as well as other rickettsial infections. Although specific laboratory diagnosis and treatment for this flea-borne rickettsiosis are detailed in the scientific literature, it is possible that most human cases are not being diagnosed properly. Furthermore, since the cat flea infests different common domestic animals, contact with humans may be more frequent than reported. In this review, we provide an update on methods for specific detection of human infection by R. felis described in the literature, as well as the treatment prescribed to the patients. Considering advances in molecular detection tools, as well as options for as-yet-unreported isolation of R. felis from patients in cell culture, increased diagnosis and characterization of this emerging pathogen is warranted.Keywords: Rickettsia felis, human cases, laboratory diagnosis, treatment

Hun L; Troyo A

2012-01-01

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Rickettsia felis in Rhipicephalus sanguineus from Two Distant Chilean Cities.  

Science.gov (United States)

Abstract Introduction: Rickettsia felis is an emerging agent considered a human threat; although its natural reservoir and agent of transmission is the cat flea, it has been also found in other vectors. R. felis has been identified in Chile in cat fleas and in one specimen of Rhipicephalus sanguineus collected in the Metropolitan Region. The objective of this study was to detect the presence of Rickettsia spp. in R. sanguineus from dogs of two different and distant geographical areas in Chile. Material and Methods: We performed a domiciliary sampling in urban and rural localities of two distant areas of the country-the Metropolitan Region in the center and the northern city of Arica. A total of 460 households were visited; one dog per household was included in the study and ectoparasites were collected from them. Results: R. sanguineus was found in 50% of the 460 dogs. R. felis was identified by amplification and sequencing of gltA, ompA, and ompB genes in R. sanguineus from both regions, with predominance in Arica. Discussion: The presence of R. felis in R. sanguineus from two distant regions of Chile suggests that this rickettsial agent is well established in the country. Considering that no human spotted fever group infections have been recognized in the country, the results should alert clinicians about such possible cases. The role of R. sanguineus in the epidemiology and transmission of R. felis should be further investigated. PMID:23659352

Abarca, Katia; López, Javier; Acosta-Jamett, Gerardo; Martínez-Valdebenito, Constanza

2013-05-09

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Analysis of the Rickettsia africae genome reveals that virulence acquisition in Rickettsia species may be explained by genome reduction  

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Full Text Available Abstract Background The Rickettsia genus includes 25 validated species, 17 of which are proven human pathogens. Among these, the pathogenicity varies greatly, from the highly virulent R. prowazekii, which causes epidemic typhus and kills its arthropod host, to the mild pathogen R. africae, the agent of African tick-bite fever, which does not affect the fitness of its tick vector. Results We evaluated the clonality of R. africae in 70 patients and 155 ticks, and determined its genome sequence, which comprises a circular chromosome of 1,278,540 bp including a tra operon and an unstable 12,377-bp plasmid. To study the genetic characteristics associated with virulence, we compared this species to R. prowazekii, R. rickettsii and R. conorii. R. africae and R. prowazekii have, respectively, the less and most decayed genomes. Eighteen genes are present only in R. africae including one with a putative protease domain upregulated at 37°C. Conclusion Based on these data, we speculate that a loss of regulatory genes causes an increase of virulence of rickettsial species in ticks and mammals. We also speculate that in Rickettsia species virulence is mostly associated with gene loss. The genome sequence was deposited in GenBank under accession number [GenBank: NZ_AAUY01000001].

Fournier Pierre-Edouard; El Karkouri Khalid; Leroy Quentin; Robert Catherine; Giumelli Bernadette; Renesto Patricia; Socolovschi Cristina; Parola Philippe; Audic Stéphane; Raoult Didier

2009-01-01

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Rickettsiae in arthropods collected from red foxes (Vulpes vulpes) in France.  

UK PubMed Central (United Kingdom)

The aim of our study was to detect the presence of Rickettsia spp. and Bartonella spp. in ticks and fleas collected from red foxes (Vulpes vulpes) in southeastern France during 2008. Using a genus-specific quantitative PCR (qPCR) assay, which was followed by a species-specific qPCR assay for the positive samples, 45.2% (33/73) of ticks (Rhipicephalus turanicus) were found to be infected with Rickettsia massiliae. 10.5% (2/19) of the fleas (Archaeopsylla erinacei) collected in the study tested positive for Rickettsia felis. A genus-specific qPCR assay did not reveal any Bartonella species in any of the ticks or fleas collected. The role of red foxes in the epidemiology of spotted fever caused by Rickettsiae species requires further investigation.

Marié JL; Davoust B; Socolovschi C; Mediannikov O; Roqueplo C; Beaucournu JC; Raoult D; Parola P

2012-01-01

176

Molecular detection of various rickettsiae in mites (acari: trombiculidae) in southern Jeolla Province, Korea.  

Science.gov (United States)

This study revealed the presence of various rickettsial agents in mites from wild rodents collected in Southern Jeolla Province, Korea, by nested polymerase chain reaction (PCR) and sequence analysis of a partial citrate synthase and rickettsia outer membrane protein B genes. Rickettsial agents closely related to the Rickettsia species TwKM02, R. australis, and the Rickettsia species Cf15 were successfully identified in this study, for the first time in Korea, and R. japonica, R. akari, R. conorii, R. felis, and R. typhi were also detected, as previously described. The data presented in this paper extend knowledge on the geographic distribution of SFG rickettsiae in eastern Asia and it may necessary to consider the role of mites in rickettsial transmission. PMID:17380050

Choi, Yeon-Joo; Lee, Eun-Mi; Park, Jin-Mi; Lee, Kyung-Min; Han, Seung-Hoon; Kim, Jae-Kwon; Lee, Seung-Hyun; Song, Hyeon-Je; Choi, Myung-Sik; Kim, Ik-Sang; Park, Kyung-Hee; Jang, Won-Jong

2007-01-01

177

Molecular detection of various rickettsiae in mites (acari: trombiculidae) in southern Jeolla Province, Korea.  

UK PubMed Central (United Kingdom)

This study revealed the presence of various rickettsial agents in mites from wild rodents collected in Southern Jeolla Province, Korea, by nested polymerase chain reaction (PCR) and sequence analysis of a partial citrate synthase and rickettsia outer membrane protein B genes. Rickettsial agents closely related to the Rickettsia species TwKM02, R. australis, and the Rickettsia species Cf15 were successfully identified in this study, for the first time in Korea, and R. japonica, R. akari, R. conorii, R. felis, and R. typhi were also detected, as previously described. The data presented in this paper extend knowledge on the geographic distribution of SFG rickettsiae in eastern Asia and it may necessary to consider the role of mites in rickettsial transmission.

Choi YJ; Lee EM; Park JM; Lee KM; Han SH; Kim JK; Lee SH; Song HJ; Choi MS; Kim IS; Park KH; Jang WJ

2007-01-01

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A focus of dogs and Rickettsia massiliae-infected Rhipicephalus sanguineus in California.  

UK PubMed Central (United Kingdom)

A recurrent focus of Rhipicephalus sanguineus infestation was investigated in a suburban area of southern California after reports of suspected Rocky Mountain spotted fever in two dogs on the same property. Abundant quantities of Rh. sanguineus were collected on the property and repeatedly from each dog, and Rickettsia massiliae DNA was detected by polymerase chain reaction (PCR). Whole blood and serum samples from four dogs were tested by using PCR and microimmunofluorescent assay for antibodies against spotted fever group rickettsiae. Serum samples from all four dogs contained antibodies reactive with R. massiliae, R. rhipicephali, R. rickettsii, and 364D Rickettsia but no rickettsial DNA was detected by PCR of blood samples. Serum cross-absorption and Western blot assays implicated R. massiliae as the most likely spotted fever group rickettsiae responsible for seropositivity. To our knowledge, this is the first detection of R. massiliae in ticks in California.

Beeler E; Abramowicz KF; Zambrano ML; Sturgeon MM; Khalaf N; Hu R; Dasch GA; Eremeeva ME

2011-02-01

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Ultrastructural and molecular identification of a new Rickettsia endosymbiont in the springtail Onychiurus sinensis (Hexapoda, Collembola).  

UK PubMed Central (United Kingdom)

In this paper we provide microscopic and molecular evidence for the presence of an endosymbiontic bacterium in male and female gonads of the soil arthropod Onychiurus sinensis. The sequence of the gene encoding for the 16S rRNA shows that the bacterium is a member of the genus Rickettsia, and some anomalies presumably associated with the presence of these microorganisms have been detected. Although the Rickettsia found in O. sinensis has the smallest genetic divergence with Rickettsia bellii, the phylogenetic analysis fails to find support for a sister-group relationship between these two species, rather suggesting that most Rickettsia species/strains isolated in various arthropods have rapidly evolved and diversified in what appears to be a sudden burst of evolution.

Frati F; Negri I; Fanciulli PP; Pellecchia M; Dallai R

2006-11-01

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Phospholipase A and the interaction of Rickettsia prowazekii and mouse fibroblasts (L-929 cells)  

International Nuclear Information System (INIS)

L-929 cells were killed when approximately 50 viable Rickettsia prowazekii organisms per L-cell were centrifuged onto a monolayer. The glycerophospholipids of the L-cell were hydrolyzed to lysophosphatides and free fatty acids. Concomitantly, there was a loss of membrane integrity as shown by release of lactate dehydrogenase and 86Rb and permeability to trypan blue dye. No glycerophospholipid hydrolysis or cytotoxicity occurred when the rickettsiae were inactivated by heat, UV irradiation, N-ethylmaleimide, or metabolic inhibitors before their addition to the L-929 cells. On the other hand, treatment of the L929 cells with the cytoskeleton agents colchicine or cytochalasin B or with N-ethylmaleimide inhibited neither the phospholipase A activity nor the loss of membrane integrity. Cytochalasin B-treated cells could be damaged by even small numbers of rickettsiae. We suggest that this phospholipase A activity is used by the rickettsiae to escape from the phagosomes into the cytoplasm of host cells.

1982-01-01

 
 
 
 
181

Clinical and laboratorial evidence of Rickettsia felis infections in Latin America  

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Full Text Available After the discovery and initial characterization of Rickettsia felis in 1992 by Azad and cols, and the subsequent first description of a human case of infection in 1994, there have been two communications of human rickettsiosis cases caused by Rickettsia felis in Latin America. The first one was published in 2000 by Zavala-Velazquez and cols in Mexico. In 2001 Raoult and cols described the occurrence of two human cases of Rickettsia felis rickettsiosis in Brazil. In the present discussion these two articles were compared and after the description of the principal signs and symptoms, it was concluded that more studies are needed with descriptions of a greater number of patients to establish the true frequency of the clinical signs and symptoms present in Rickettsia felis rickettsiosis.

Galvão Márcio Antônio Moreira; Mafra Cláudio; Chamone Chequer Buffe; Calic Simone Berger; Zavala-Velazquez Jorge E.; Walker David Hughes

2004-01-01

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Detección de Rickettsia spp. en ectoparásitos de animales domésticos y silvestres de la Reserva Natural Privada Cerro Chucantí y comunidades aledañas, Panamá, 2007-2010/ Detection of Rickettsia in ectoparasites of wild and domestic mammals from the Cerro Chucanti private reserve and from neighboring towns, Panamá, 2007-2010  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Introducción. Los ectoparásitos son los principales vectores de rickettsiosis. En Panamá se tienen escasos datos sobre los artrópodos que pudieran considerarse vectores o reservorios. Objetivos. Presentar datos sobre la presencia de Rickettsia spp. en ectoparásitos de fauna silvestre y animales domésticos en la Reserva Natural Privada Cerro Chucantí y poblados vecinos. Materiales y métodos. Se revisaron 9 personas, 95 mamíferos domésticos y 48 silvestres. Los an (more) imales domésticos se examinaron con anuencia del propietario, mientras que la fauna silvestre se capturó con trampas Sherman y Tomahawk. Se extrajeron 21 especies de ectoparásitos: pulgas, piojos, garrapatas y otros ácaros, los cuales se preservaron en etanol al 95 %. Se extrajo material genético de garrapatas y pulgas para ser analizado por técnicas moleculares en la detección de Rickettsia spp. Resultados. Se practicaron 425 reacciones de PCR, de las cuales, 270 resultaron negativas y 155 positivas. De las positivas, 86 amplificaron para el gen gltA (55 % de las positivas); de estos también amplificaron 41 (26 %) para ompA. Se encontró material genético de Rickettsia amblyommii, en garrapatas de caballos (Amblyomma cajennense, Dermacentor nitens), de perros (Rhipicephalus sanguineus) y ninfas de Amblyomma recolectadas en el bosque. Además, se detectó ADN de R. felis en pulgas Ctenocephalides felis de perros. Conclusiones. Se pudo detectar la presencia de R. amblyommii y R. felis en garrapatas y pulgas de animales domésticos de los poblados cercanos a Cerro Chucantí, aun cuando no se pudo encontrar material genético de Rickettsia en ectoparásitos de la fauna silvestre. Abstract in english Introduction. Ectoparasites are the main vectors of rickettsiosis. In Panama, however, limited data are available concerning the arthropod species that serve as vectors or reservoirs. Objectives. Data are presented concerning the presence of Rickettsia in ectoparasites of wildlife and domestic animals in the Cerro Chucantí private nature reserve and in neighboring villages. Materials and methods. Nine humans, 95 domestic mammals and 48 wild mammals were examined. Twenty- (more) one species of ectoparasites were obtained, including fleas, lice, ticks and mites. These were preserved in 95% ethanol. Later, the DNA was extracted from the ticks and fleas and analyzed by molecular techniques to detect presence of Rickettsia. Results. Of a total of 425 PCR reactions, 270 were positive for Rickettsia and 155 negative. Among the positive samples, 86 PCR amplified for the gltA gene (55% of positives) and 41 of these also amplified the ompA gene. DNA of Rickettsiaamblyommii was found in horses ticks (Amblyomma cajennense, Dermacentor nitens), dogs ticks (Rhipicephalus sanguineus) and free living nymphs in the forest. Additionally, DNA of R. felis was found in fleas from dogs Ctenocephalides felis. Conclusions. The presence of R. amblyommii and R. felis was detected in ticks and fleas of domestic animals in villages near Cerro Chucanti; however no Rickettsia DNA was found in ectoparasites of non-domestic wildlife.

Bermúdez, Sergio; Miranda, Roberto; Zaldívar, Yamitze; González, Publio; Berguido, Guido; Trejos, Diomedes; Pascale, Juan M; Labruna, Marcelo

2012-06-01

183

Detection of Rickettsia in ectoparasites of wild and domestic mammals from the Private Reserve Cerro Chucanti and neighboring towns, Panamá (2007-2010) Detección de Rickettsia sp. en ectoparásitos de animales domésticos y silvestres de la Reserva Natural Privada Cerro Chucantí y comunidades aledañas, Panamá (2007-2010)  

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Full Text Available Introduction. Ectoparasites are the main vectors of rickettsiosis. In Panama, have limited data on the arthropods that may be considered vectors or reservoirs.Objectives. The aim is to present data on the presence of Rickettsia in ectoparasites of wildlife and domestic animals in the Private Natural Reserve Cerro Chucantí and neighboring villages.Materials and methods. We evaluated 9 humans, 95 domestic mammals and 48 wild. From these, were 21 species of ectoparasites, including fleas, lice, ticks and mites, which were preserved in 95% ethanol. Genetic material was extracted from ticks and fleas to be analyzed by molecular techniques in the detection of Rickettsia.Results. A total of 425 were carried out PCR reactions, of which 270 were positive and 155 negative. The positive, 86 PCR amplified for the gltA gene (55% of positives) of these also amplified 41 (26%) for ompA. DNA of Rickettsia amblyommii was found in horses ticks (Amblyomma cajennense, Dermacentor nitens), dogs ticks (Rhipicephalus sanguineus) and free living nymph in forest. Adicionally, DNA of R. felis was found in dogs fleas Ctenocephalides felis.Conclusions. Detected the presence of R. amblyommii and R. felis in ticks and fleas of domestic animals of the villages near Cerro Chucanti, even if they were unable to find genetic material from Rickettsia in ectoparasites of wildlife.Introducción. Los ectoparásitos son los principales vectores de rickettsiosis. En Panamá se tienen escasos datos sobre los artrópodos que pudieran ser considerados vectores o reservorios.Objetivos. Presentar datos sobre la presencia de Rickettsia en ectoparásitos de fauna silvestre y animales domésticos en la Reserva Natural Privada Cerro Chucantí y poblados vecinos.Materiales y métodos. Se revisaron 9 personas, 95 mamíferos domésticos y 48 silvestres. Los animales domésticos fueron revisados con anuencia del propietario, mientras que para la captura de fauna silvestre se capturaron con trampas Sherman y Tomahawk. De estos se extrajeron 21 especies de ectoparásitos: pulgas, piojos, garrapatas y otros ácaros, los cuales fueron preservados en etanol al 95%. Se extrajo material genético de garrapatas y pulgas para ser analizados por técnicas moleculares en la detección de Rickettsia.Resultados. Se realizaron 425 reacciones de PCR, de los cuales 270 resultaron negativos y 155 positivos. De los positivos, 86 amplificaron para el gen gltA (55% de los positivos), de estos también amplificaron 41 (26%) para ompA. Se encontró material genético de Rickettsia amblyommii, en garrapatas de caballos (Amblyomma cajennense, Dermacentor nitens), de perros (Rhipicephalus sanguineus) y ninfas de Amblyomma recolectadas en el bosque. Adicionalmente se detectó ADN de R. felis en pulgas Ctenocephalides felis de perros.Conclusiones. Se pudo detectar la presencia de R. amblyommii y R. felis en garrapatas y pulgas de animales domésticos de los poblados cercanos a Cerro Chucanti, aun cuando no se pudo encontrar material genético de Rickettsia en ectoparásitos de fauna silvestre.

Sergio Eduardo Bermúdez; Roberto Miranda; Yamitzel Zaldívar; Publio González; Guido Berguido; Diomedes Trejos; Juan M. Pascale; Marcelo Labruna

2011-01-01

184

Rickettsia spp. 364D causing a cluster of eschar-associated illness, California.  

Science.gov (United States)

We describe the clinical course of the first 3 pediatric cases infected with Rickettsia spp. 364D. Although the pathogen was identified in California ticks decades ago, only recently have human cases been documented. Clinical features are generally mild, characterized by eschar, fever, headache, malaise and lymphadenopathy. Antigenic similarity among rickettsiae leads to cross-reactive antibody responses; definitive diagnosis requires molecular methods. PMID:23594588

Johnston, Samantha H; Glaser, Carol A; Padgett, Kerry; Wadford, Debra A; Espinosa, Alex; Espinosa, Natasha; Eremeeva, Marina E; Tait, Karen; Hobson, Barbara; Shtivelman, Sarit; Hsieh, Charlotte; Messenger, Sharon L

2013-09-01

185

Morphometric and quantitative characterization of atrial ganglion neurons from the intercaval region in dogs with dilated cardiomyopathy/ Caracterização morfométrica e quantitativa dos neurônios ganglionares atriais da faixa intercaval de cães com cardiomiopatia dilatada  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Avaliaram-se quantitativa, morfométrica e qualitativamente os neurônios atriais da faixa intercaval de cães com cardiomiopatia dilatada (CMD). Os neurônios dos gânglios nervosos de cães com CMD eram maiores que os dos cães controle. A histopatologia do miocárdio ventricular e dos neurônios ganglionares confirmou a CMD e demonstrou evidente processo degenerativo neuronal ganglionar. Cães com CMD em fase crônica apresentavam cardioneuropatia secundária, provavelmente pela privação da inervação parassimpática cardíaca. Abstract in english The quantity, morphometry, and quality of atrial neurons from the intercaval region in dogs with dilated cardiomyopathy (DCM) were evaluated. Dogs with DCM had greater ganglion neurons than control dogs. The histologic evaluation of the ventricular myocardium and ganglion neurons confirmed DCM and showed the degeneration of ganglion neurons. Dogs with chronic DCM had a secondary cardioneuropathy owing to impaired parasympathetic neural control.

Camacho, A.A.; Oliveira-Alves, R.; Klein, R.P.; Sousa, M.G.

2007-12-01

186

Morphometric and quantitative characterization of atrial ganglion neurons from the intercaval region in dogs with dilated cardiomyopathy Caracterização morfométrica e quantitativa dos neurônios ganglionares atriais da faixa intercaval de cães com cardiomiopatia dilatada  

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Full Text Available The quantity, morphometry, and quality of atrial neurons from the intercaval region in dogs with dilated cardiomyopathy (DCM) were evaluated. Dogs with DCM had greater ganglion neurons than control dogs. The histologic evaluation of the ventricular myocardium and ganglion neurons confirmed DCM and showed the degeneration of ganglion neurons. Dogs with chronic DCM had a secondary cardioneuropathy owing to impaired parasympathetic neural control.Avaliaram-se quantitativa, morfométrica e qualitativamente os neurônios atriais da faixa intercaval de cães com cardiomiopatia dilatada (CMD). Os neurônios dos gânglios nervosos de cães com CMD eram maiores que os dos cães controle. A histopatologia do miocárdio ventricular e dos neurônios ganglionares confirmou a CMD e demonstrou evidente processo degenerativo neuronal ganglionar. Cães com CMD em fase crônica apresentavam cardioneuropatia secundária, provavelmente pela privação da inervação parassimpática cardíaca.

A.A. Camacho; R. Oliveira-Alves; R.P. Klein; M.G. Sousa

2007-01-01

187

Detection of a novel spotted fever group Rickettsia in the gophertortoise tick.  

UK PubMed Central (United Kingdom)

The gophertortoise tick, Amblyomma tuberculatum (Marx), is distributed throughout the southeastern United States, and its immature life stages have been reported to occasionally bite humans. Here we report detection of a novel spotted fever group (SFG) Rickettsia in A. tuberculatum ticks collected in the southern United States. Among questing ticks collected in Georgia, 10 pools of larvae were identified as gophertortoise ticks, A. tuberculatum. Each of these samples was positive for SFG Rickettsiae. The restriction fragment-length polymorphism profiles were identical to each other, but distinct from those of other rickettsiae previously found in Amblyomma spp. ticks. Partial genetic characterization of the novel agent was achieved by sequencing the 17 kDa, gltA, ompB, ompA, rpoB, and sca4 genes. Analysis of a concatenated tree of four genes (gltA, ompB, ompA, and sca4) demonstrates close relatedness of the detected Rickettsia to several SFG Rickettsia spp. The identical rickettsial DNA was detected in 50 and 70% of adult A. tuberculatum ticks from Mississippi and Florida, respectively. The results indicate wide distribution of a novel Rickettsia, capability for transovarial transmission, and high prevalence in tested tick populations.

Zemtsova GE; Gleim E; Yabsley MJ; Conner LM; Mann T; Brown MD; Wendland L; Levin ML

2012-05-01

188

Identification and localization of a Rickettsia sp. in Bemisia tabaci (Homoptera: Aleyrodidae).  

UK PubMed Central (United Kingdom)

Whiteflies (Homoptera: Aleyrodidae) are sap-sucking insects that harbor "Candidatus Portiera aleyrodidarum," an obligatory symbiotic bacterium which is housed in a special organ called the bacteriome. These insects are also home for a diverse facultative microbial community which may include Hamiltonella, Arsenophonus, Fritchea, Wolbachia, and Cardinium spp. In this study, the bacteria associated with a B biotype of the sweet potato whitefly Bemisia tabaci were characterized using molecular fingerprinting techniques, and a Rickettsia sp. was detected for the first time in this insect family. Rickettsia sp. distribution, transmission and localization were studied using PCR and fluorescence in situ hybridizations (FISH). Rickettsia was found in all 20 Israeli B. tabaci populations screened but not in all individuals within each population. A FISH analysis of B. tabaci eggs, nymphs, and adults revealed a unique concentration of Rickettsia around the gut and follicle cells, as well as a random distribution in the hemolymph. We postulate that the Rickettsia enters the oocyte together with the bacteriocytes, leaves these symbiont-housing cells when the egg is laid, multiplies and spreads throughout the egg during embryogenesis and, subsequently, disperses throughout the body of the hatching nymph, excluding the bacteriomes. Although the role Rickettsia plays in the biology of the whitefly is currently unknown, the vertical transmission on the one hand and the partial within-population infection on the other suggest a phenotype that is advantageous under certain conditions but may be deleterious enough to prevent fixation under others.

Gottlieb Y; Ghanim M; Chiel E; Gerling D; Portnoy V; Steinberg S; Tzuri G; Horowitz AR; Belausov E; Mozes-Daube N; Kontsedalov S; Gershon M; Gal S; Katzir N; Zchori-Fein E

2006-05-01

189

Lysis of cells infected with typhus group rickettsiae by a human cytotoxic T cell clone  

International Nuclear Information System (INIS)

Cytolytic human T cells clones generated in response to the intracellular bacterium Rickettsia typhi were characterized. Growing clones were tested for their ability to proliferate specifically in response to antigens derived from typhus group rickettsiae or to lyse targets infected with R. typhi or Rickettsia prowazekii, as measured by 51Cr-release from target cells. Two clones were able to lyse targets infected with typhus group rickettsiae. One of these clones was more fully characterized because of its rapid growth characteristics. This cytolytic clone was capable of lysing an autologous infected target as well as a target matched for class I and II histocompatibility leukocyte antigens (HLA). It was not capable, however, of lysing either a target mismatched for both class I and II HLA or a target partially matched for class I HLA. In addition, the clone exhibited specificity in that it was able to lyse an autologous target infected with typhus group rickettsiae, but did not lyse an autologous target infected with an antigenically distinct rickettsial species, Rickettsia tsutsugamushi. These results demonstrate, for the first time, that cells infected with intracellular bacteria can be lysed by human cytotoxic T lymphocytes.

1987-01-01

190

Genome sequence of Rickettsia bellii illuminates the role of amoebae in gene exchanges between intracellular pathogens.  

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Full Text Available The recently sequenced Rickettsia felis genome revealed an unexpected plasmid carrying several genes usually associated with DNA transfer, suggesting that ancestral rickettsiae might have been endowed with a conjugation apparatus. Here we present the genome sequence of Rickettsia bellii, the earliest diverging species of known rickettsiae. The 1,552,076 base pair-long chromosome does not exhibit the colinearity observed between other rickettsia genomes, and encodes a complete set of putative conjugal DNA transfer genes most similar to homologues found in Protochlamydia amoebophila UWE25, an obligate symbiont of amoebae. The genome exhibits many other genes highly similar to homologues in intracellular bacteria of amoebae. We sought and observed sex pili-like cell surface appendages for R. bellii. We also found that R. bellii very efficiently multiplies in the nucleus of eukaryotic cells and survives in the phagocytic amoeba, Acanthamoeba polyphaga. These results suggest that amoeba-like ancestral protozoa could have served as a genetic "melting pot" where the ancestors of rickettsiae and other bacteria promiscuously exchanged genes, eventually leading to their adaptation to the intracellular lifestyle within eukaryotic cells.

Ogata Hiroyuki; La Scola Bernard; Audic Stéphane; Renesto Patricia; Blanc Guillaume; Robert Catherine; Fournier Pierre-Edouard; Claverie Jean-Michel; Raoult Didier

2006-01-01

191

Las Rickettsias del grupo de las fiebres manchadas: Respuesta inmune y sus proteínas inmunodominantes/ Spotted fever Rickettsiae: Their immunodominant proteins and immune response  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The organisms of Rickettsia species are Gram (-) bacteria that cause severe illnesses in humans and are an important health problem in several countries around the world, including Mexico. The presence of different antigens between species and also in different strains of the same specie is an obstacle for vaccine development and serological diagnosis. There are important advances in the knowledge of the rickettsial antigenic structure and the resulting immune response in (more) infected hosts, including humans. This review covers these topics and provides an overview about the development of vaccines and accessible diagnostic methods for diseases caused by Rickettsia (Rev Méd Chile 2004; 132: 381-7).

Zavala C, Jorge; Ruiz S, Alfredo; Zavala V, Jorge

2004-03-01

192

Experimental infection of Amblyomma aureolatum ticks with Rickettsia rickettsii.  

UK PubMed Central (United Kingdom)

We experimentally infected Amblyomma aureolatum ticks with the bacterium Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever (RMSF). These ticks are a vector for RMSF in Brazil. R. rickettsii was efficiently conserved by both transstadial maintenance and vertical (transovarial) transmission to 100% of the ticks through 4 laboratory generations. However, lower reproductive performance and survival of infected females was attributed to R. rickettsii infection. Therefore, because of the high susceptibility of A. aureolatum ticks to R. rickettsii infection, the deleterious effect that the bacterium causes in these ticks may contribute to the low infection rates (<1%) usually reported among field populations of A. aureolatum ticks in RMSF-endemic areas of Brazil. Because the number of infected ticks would gradually decrease after each generation, it seems unlikely that A. aureolatum ticks could sustain R. rickettsii infection over multiple successive generations solely by vertical transmission.

Labruna MB; Ogrzewalska M; Soares JF; Martins TF; Soares HS; Moraes-Filho J; Nieri-Bastos FA; Almeida AP; Pinter A

2011-05-01

193

Molecular typing of novel Rickettsia rickettsii isolates from Arizona.  

UK PubMed Central (United Kingdom)

Seven isolates of Rickettsia rickettsii were obtained from a skin biopsy, two whole-blood specimens, and from Rhipicephalus sanguineus ticks from eastern Arizona. Molecular typing of seven isolates of R. rickettsii and DNA samples from two other Rh. sanguineus ticks infected with R. rickettsii was conducted by PCR and DNA sequencing of rompA and 12 variable-number tandem repeat regions (VNTRs). All DNA specimens from Arizona were identical to each other and to reference human and Dermacentor andersoni isolates of R. rickettsii from Montana in their rOmpA gene sequences and 10 VNTRs. Two of the twelve VNTRs had differences in the number of repeat sequences in isolates from Arizona compared to those from Montana, thus conferring the novelty of the Rh. sanguineus-associated R. rickettsii.

Eremeeva ME; Bosserman E; Zambrano M; Demma L; Dasch GA

2006-10-01

194

Development of three quantitative real-time PCR assays for the detection of Rickettsia raoultii, Rickettsia slovaca, and Rickettsia aeschlimannii and their validation with ticks from the country of Georgia and the Republic of Azerbaijan.  

UK PubMed Central (United Kingdom)

A previous surveillance study of human pathogens within ticks collected in the country of Georgia showed a relatively high infection rate for Rickettsia raoultii, R. slovaca, and R. aeschlimannii. These 3 spotted fever group rickettsiae are human pathogens: R. raoultii and R. slovaca cause tick-borne lymphadenopathy (TIBOLA), and R. aeschlimannii causes an infection characterized by fever and maculopapular rash. Three quantitative real-time polymerase chain reaction (qPCR) assays, Rraoul, Rslov, and Raesch were developed and optimized to detect R. raoultii, R. slovaca, and R. aeschlimannii, respectively, by targeting fragments of the outer membrane protein B gene (ompB) using species-specific molecular beacon or TaqMan probes. The 3 qPCR assays showed 100% specificity when tested against a rickettsiae DNA panel (n=20) and a bacteria DNA panel (n=12). The limit of detection was found to be at least 3 copies per reaction for all assays. Validation of the assays using previously investigated tick nucleic acid preparations, which included Rickettsia-free tick samples, tick samples that contain R. raoultii, R. slovaca, R. aeschlimannii, and other Rickettsia spp., gave 100% sensitivity for all 3 qPCR assays. In addition, a total of 65 tick nucleic acid preparations (representing 259 individual ticks) collected from the country of Georgia and the Republic of Azerbaijan in 2009 was tested using the 3 qPCR assays. R. raoultii, R. slovaca, and R. aeschlimannii were not detected in any ticks (n=31) from the Republic of Azerbaijan, but in the ticks from the country of Georgia (n=228) the minimal infection rate for R. raoultii and R. slovaca in Dermacentor marginatus was 10% and 4%, respectively, and for R. aeschlimannii in Haemaphysalis sulcata and Hyalomma spp. it was 1.9% and 20%, respectively.

Jiang J; You BJ; Liu E; Apte A; Yarina TR; Myers TE; Lee JS; Francesconi SC; O'Guinn ML; Tsertsvadze N; Vephkhvadze N; Babuadze G; Sidamonidze K; Kokhreidze M; Donduashvili M; Onashvili T; Ismayilov A; Agayev N; Aliyev M; Muttalibov N; Richards AL

2012-12-01

195

Development of three quantitative real-time PCR assays for the detection of Rickettsia raoultii, Rickettsia slovaca, and Rickettsia aeschlimannii and their validation with ticks from the country of Georgia and the Republic of Azerbaijan.  

Science.gov (United States)

A previous surveillance study of human pathogens within ticks collected in the country of Georgia showed a relatively high infection rate for Rickettsia raoultii, R. slovaca, and R. aeschlimannii. These 3 spotted fever group rickettsiae are human pathogens: R. raoultii and R. slovaca cause tick-borne lymphadenopathy (TIBOLA), and R. aeschlimannii causes an infection characterized by fever and maculopapular rash. Three quantitative real-time polymerase chain reaction (qPCR) assays, Rraoul, Rslov, and Raesch were developed and optimized to detect R. raoultii, R. slovaca, and R. aeschlimannii, respectively, by targeting fragments of the outer membrane protein B gene (ompB) using species-specific molecular beacon or TaqMan probes. The 3 qPCR assays showed 100% specificity when tested against a rickettsiae DNA panel (n=20) and a bacteria DNA panel (n=12). The limit of detection was found to be at least 3 copies per reaction for all assays. Validation of the assays using previously investigated tick nucleic acid preparations, which included Rickettsia-free tick samples, tick samples that contain R. raoultii, R. slovaca, R. aeschlimannii, and other Rickettsia spp., gave 100% sensitivity for all 3 qPCR assays. In addition, a total of 65 tick nucleic acid preparations (representing 259 individual ticks) collected from the country of Georgia and the Republic of Azerbaijan in 2009 was tested using the 3 qPCR assays. R. raoultii, R. slovaca, and R. aeschlimannii were not detected in any ticks (n=31) from the Republic of Azerbaijan, but in the ticks from the country of Georgia (n=228) the minimal infection rate for R. raoultii and R. slovaca in Dermacentor marginatus was 10% and 4%, respectively, and for R. aeschlimannii in Haemaphysalis sulcata and Hyalomma spp. it was 1.9% and 20%, respectively. PMID:23182543

Jiang, Ju; You, Brian J; Liu, Evan; Apte, Anisha; Yarina, Tamasin R; Myers, Todd E; Lee, John S; Francesconi, Stephen C; O'Guinn, Monica L; Tsertsvadze, Nikoloz; Vephkhvadze, Nino; Babuadze, Giorgi; Sidamonidze, Ketevan; Kokhreidze, Maka; Donduashvili, Marina; Onashvili, Tinatin; Ismayilov, Afrail; Agayev, Nigar; Aliyev, Mubariz; Muttalibov, Nizam; Richards, Allen L

2012-11-20

196

Synanthropic birds associated with high prevalence of tick-borne rickettsiae and with the first detection of Rickettsia aeschlimannii in Hungary.  

Science.gov (United States)

The aim of this study was to analyze synanthropic birds as risk factors for introducing ticks and tick-borne pathogens into human settlements, with an emphasis on rickettsiae. Altogether 184 subadult ticks were found on 5846 birds. Tick infestation was most prevalent during the spring. In this sample group the majority of ticks were molecularly identified as Ixodes ricinus, and three individuals collected from the European robin as Hyalomma marginatum marginatum. The latter is the first molecularly confirmed occurrence of this species in Hungary. Rickettsia aeschlimannii was detected in H. marginatum, also for the first time in Hungary, and in ticks from an urbanized bird species north of the Mediterranean countries. The overall prevalence range of rickettsiae (including R. helvetica and R. monacensis) in ticks of synanthropic birds was 29-40%, exceeding that in questing ticks of relevant species reported earlier. Additionally, in specimens of I. ricinus, the presence of Borrelia burgdorferi sensu lato (s.l.), Anaplasma phagocytophilum, and a new Francisella-like genotype was also verified. Thus, it can be concluded that birds with urban or periurban habitats pose a high risk as tick carriers and reservoirs of zoonotic agents, especially of rickettsiae. PMID:23289394

Hornok, Sándor; Csörg?, Tibor; de la Fuente, José; Gyuranecz, Miklós; Privigyei, Csaba; Meli, Marina L; Kreizinger, Zsuzsa; Gönczi, Enik?; Fernández de Mera, Isabel G; Hofmann-Lehmann, Regina

2013-01-05

197

Synanthropic birds associated with high prevalence of tick-borne rickettsiae and with the first detection of Rickettsia aeschlimannii in Hungary.  

UK PubMed Central (United Kingdom)

The aim of this study was to analyze synanthropic birds as risk factors for introducing ticks and tick-borne pathogens into human settlements, with an emphasis on rickettsiae. Altogether 184 subadult ticks were found on 5846 birds. Tick infestation was most prevalent during the spring. In this sample group the majority of ticks were molecularly identified as Ixodes ricinus, and three individuals collected from the European robin as Hyalomma marginatum marginatum. The latter is the first molecularly confirmed occurrence of this species in Hungary. Rickettsia aeschlimannii was detected in H. marginatum, also for the first time in Hungary, and in ticks from an urbanized bird species north of the Mediterranean countries. The overall prevalence range of rickettsiae (including R. helvetica and R. monacensis) in ticks of synanthropic birds was 29-40%, exceeding that in questing ticks of relevant species reported earlier. Additionally, in specimens of I. ricinus, the presence of Borrelia burgdorferi sensu lato (s.l.), Anaplasma phagocytophilum, and a new Francisella-like genotype was also verified. Thus, it can be concluded that birds with urban or periurban habitats pose a high risk as tick carriers and reservoirs of zoonotic agents, especially of rickettsiae.

Hornok S; Csörg? T; de la Fuente J; Gyuranecz M; Privigyei C; Meli ML; Kreizinger Z; Gönczi E; Fernández de Mera IG; Hofmann-Lehmann R

2013-02-01

198

Proposal to create subspecies of Rickettsia conorii based on multi-locus sequence typing and an emended description of Rickettsia conorii  

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Full Text Available Abstract Background Rickettsiae closely related to the Malish strain, the reference Rickettsia conorii strain, include Indian tick typhus rickettsia (ITTR), Israeli spotted fever rickettsia (ISFR), and Astrakhan fever rickettsia (AFR). Although closely related genotypically, they are distinct serotypically. Using multilocus sequence typing (MLST), we have recently found that distinct serotypes may not always represent distinct species within the Rickettsia genus. We investigated the possibility of classifying rickettsiae closely related to R. conorii as R. conorii subspecies as proposed by the ad hoc committee on reconciliation of approaches to bacterial systematics. For this, we first estimated their genotypic variability by using MLST including the sequencing of 5 genes, of 31 rickettsial isolates closely related to R. conorii strain Malish, 1 ITTR isolate, 2 isolates and 3 tick amplicons of AFR, and 2 ISFR isolates. Then, we selected a representative of each MLST genotype and used multi-spacer typing (MST) and mouse serotyping to estimate their degree of taxonomic relatedness. Results Among the 39 isolates or tick amplicons studied, four MLST genotypes were identified: i) the Malish type; ii) the ITTR type; iii) the AFR type; and iv) the ISFR type. Among these four MLST genotypes, the pairwise similarity in nucleotide sequence varied from 99.8 to 100%, 99.4 to 100%, 98.2 to 99.8%, 98.4 to 99.8%, and 99.2 to 99.9% for 16S rDNA, gltA, ompA, ompB, and sca4 genes, respectively. Representatives of the 4 MLST types were also classified within four types using MST genotyping as well as mouse serotyping. Conclusion Although homogeneous genotypically, strains within the R. conorii species show MST genotypic, serotypic, and epidemio-clinical dissimilarities. We, therefore, propose to modify the nomenclature of the R. conorii species through the creation of subspecies. We propose the names R. conorii subsp. conorii subsp. nov. (type strain = Malish, ATCC VR-613), R. conorii subspecies indica subsp. nov. (type strain = ATCC VR-597), R. conorii subspecies caspia subsp. nov. (type strain = A-167), and R. conorii subspecies israelensis subsp. nov. (type strain = ISTT CDC1). The description of R. conorii is emended to accomodate the four subspecies.

Zhu Yong; Fournier Pierre-Edouard; Eremeeva Marina; Raoult Didier

2005-01-01

199

Proposal to create subspecies of Rickettsia conorii based on multi-locus sequence typing and an emended description of Rickettsia conorii.  

UK PubMed Central (United Kingdom)

BACKGROUND: Rickettsiae closely related to the Malish strain, the reference Rickettsia conorii strain, include Indian tick typhus rickettsia (ITTR), Israeli spotted fever rickettsia (ISFR), and Astrakhan fever rickettsia (AFR). Although closely related genotypically, they are distinct serotypically. Using multilocus sequence typing (MLST), we have recently found that distinct serotypes may not always represent distinct species within the Rickettsia genus. We investigated the possibility of classifying rickettsiae closely related to R. conorii as R. conorii subspecies as proposed by the ad hoc committee on reconciliation of approaches to bacterial systematics. For this, we first estimated their genotypic variability by using MLST including the sequencing of 5 genes, of 31 rickettsial isolates closely related to R. conorii strain Malish, 1 ITTR isolate, 2 isolates and 3 tick amplicons of AFR, and 2 ISFR isolates. Then, we selected a representative of each MLST genotype and used multi-spacer typing (MST) and mouse serotyping to estimate their degree of taxonomic relatedness. RESULTS: Among the 39 isolates or tick amplicons studied, four MLST genotypes were identified: i) the Malish type; ii) the ITTR type; iii) the AFR type; and iv) the ISFR type. Among these four MLST genotypes, the pairwise similarity in nucleotide sequence varied from 99.8 to 100%, 99.4 to 100%, 98.2 to 99.8%, 98.4 to 99.8%, and 99.2 to 99.9% for 16S rDNA, gltA, ompA, ompB, and sca4 genes, respectively. Representatives of the 4 MLST types were also classified within four types using MST genotyping as well as mouse serotyping. CONCLUSION: Although homogeneous genotypically, strains within the R. conorii species show MST genotypic, serotypic, and epidemio-clinical dissimilarities. We, therefore, propose to modify the nomenclature of the R. conorii species through the creation of subspecies. We propose the names R. conorii subsp. conorii subsp. nov. (type strain = Malish, ATCC VR-613), R. conorii subspecies indica subsp. nov. (type strain = ATCC VR-597), R. conorii subspecies caspia subsp. nov. (type strain = A-167), and R. conorii subspecies israelensis subsp. nov. (type strain = ISTT CDC1). The description of R. conorii is emended to accomodate the four subspecies.

Zhu Y; Fournier PE; Eremeeva M; Raoult D

2005-01-01

200

Molecular identification of Rickettsia felis-like bacteria in Haemaphysalis sulcata ticks collected from domestic animals in southern Croatia.  

UK PubMed Central (United Kingdom)

Haemaphysalis sulcata ticks collected from sheep and goats in southern Croatia were found infected with rickettsiae. Molecular analysis of the complete gltA gene and portion of 17 kDa and ompB genes revealed the presence of Rickettsia felis-like bacteria in up to 26% of tested ticks.

Duh D; Punda-Poli? V; Trilar T; Petrovec M; Bradari? N; Avsic-Zupanc T

2006-10-01

 
 
 
 
201

Detection of a spotted fever group Rickettsia in the tick Ixodes tasmani collected from koalas in Port Macquarie, Australia.  

UK PubMed Central (United Kingdom)

Four species of Rickettsia are recognized as endemic to Australia. This study reports the detection of a new spotted fever group Rickettsia in the common marsupial tick Ixodes tasmani Neumann collected from koalas (Phascolarctos cinereus) in Port Macquarie, NSW, Australia. Based on the results of polymerase chain reaction (PCR) amplification of extracted tick DNA with primers targeting the citrate synthase gene (gltA) and the outer membrane proteins A and B (ompA. ompB), Rickettsiae were detected in 22 of 78 I. tasmani tick samples (28.2%). Sequence data obtained for the three genes displayed the closest degree of similarity to Rickettsia heilongjiangiensiss for gltA (99.4%; 331/333 bp), Rickettsia amblyommii for the ompA gene (94.8%; 417/440 bp), and both Rickettsia massiliae and Rickettsia rhipicephali for the ompB gene (97%; 770/803 bp). BLAST and phylogenetic analysis of partial sequences obtained for the three genes were found to have sufficient nucleotide variation from the current recognized Australian species to be considered a distinct spotted fever group Rickettsia.

Vilcins IM; Old JM; Deane EM

2008-07-01

202

Infection of Human Endothelial Cells with Spotted Fever Group Rickettsiae Stimulates Cyclooxygenase 2 Expression and Release of Vasoactive Prostaglandins  

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Rickettsiae, a diverse group of obligately intracellular gram-negative bacteria, include etiologic agents of the spotted fever and typhus groups of diseases. Rocky Mountain spotted fever and boutonneuse fever, due to Rickettsia rickettsii and R. conorii, respectively, are characterized by widespread...

Rydkina, Elena; Sahni, Abha; Baggs, Raymond B.; Silverman, David J.; Sahni, Sanjeev K.

203

Detection of Rickettsia spp. in Haemaphysalis ticks collected in La Rioja, Spain.  

Science.gov (United States)

In an attempt to know the potential risk of human disease after exposure to ticks in La Rioja (North of Spain), the objective of our study was to investigate the presence of Rickettsia species in Haemaphysalis ticks collected in our area. A total of 177 Haemaphysalis spp. belonging to three species (H. punctata, H. sulcata, and H. inermis) were subjected to DNA extraction and tested by polymerase chain reaction (PCR) targeting three rickettsial genes: gltA, ompB, and ompA. Six (3 H. inermis, 2 H. punctata, and 1 H. sulcata) of the 177 specimens were found to be infected (3.4%). The rickettsiae in H. inermis ticks (n = 3) were identified as Rickettsia aeschlimannii by sequencing of the genes coding for gltA, ompB, and ompA. Nucleotide sequences from H. punctata and H. sulcata samples that yielded PCR products (n = 3), showed >99% similarity with sequences of Rickettsia endosymbiont of H. sulcata and 'Candidatus Rickettsia hoogstraalii' for gltA and ompB genes, respectively. Attempts to amplify ompA from these two H. punctata and one H. sulcata failed. This study suggests that H. inermis could be a vector for tick-borne spotted fever caused by R. aeschlimannii in the north of Spain. Further studies on characterization and culture of rickettsial endosymbionts found in Haemaphysalis spp. should be performed. PMID:18454590

Portillo, Aránzazu; Santibáñez, Paula; Santibáñez, Sonia; Pérez-Martínez, Laura; Oteo, José A

2008-10-01

204

Detection of Rickettsia spp. in Haemaphysalis ticks collected in La Rioja, Spain.  

UK PubMed Central (United Kingdom)

In an attempt to know the potential risk of human disease after exposure to ticks in La Rioja (North of Spain), the objective of our study was to investigate the presence of Rickettsia species in Haemaphysalis ticks collected in our area. A total of 177 Haemaphysalis spp. belonging to three species (H. punctata, H. sulcata, and H. inermis) were subjected to DNA extraction and tested by polymerase chain reaction (PCR) targeting three rickettsial genes: gltA, ompB, and ompA. Six (3 H. inermis, 2 H. punctata, and 1 H. sulcata) of the 177 specimens were found to be infected (3.4%). The rickettsiae in H. inermis ticks (n = 3) were identified as Rickettsia aeschlimannii by sequencing of the genes coding for gltA, ompB, and ompA. Nucleotide sequences from H. punctata and H. sulcata samples that yielded PCR products (n = 3), showed >99% similarity with sequences of Rickettsia endosymbiont of H. sulcata and 'Candidatus Rickettsia hoogstraalii' for gltA and ompB genes, respectively. Attempts to amplify ompA from these two H. punctata and one H. sulcata failed. This study suggests that H. inermis could be a vector for tick-borne spotted fever caused by R. aeschlimannii in the north of Spain. Further studies on characterization and culture of rickettsial endosymbionts found in Haemaphysalis spp. should be performed.

Portillo A; Santibáñez P; Santibáñez S; Pérez-Martínez L; Oteo JA

2008-10-01

205

Spotted fever group Rickettsia in ticks from southeastern Spain natural parks.  

Science.gov (United States)

During an 8-years study, we collected from vegetation or domestic and wild mammals 1246 ticks (624 males, 511 females and 111 nymphs) belonging to 13 species in Jaen province (Andalusia) and we analyzed these ticks by PCR and sequencing for the presence of rickettsiae. Specific rickettsiae DNA was detected in 243 (19.5%) of the ticks tested. Sequence analysis of amplicons of gltA, ompA and ompB genes revealed that Ixodes ricinus were infected with R. monacensis, including strain IRS3, and R. helvetica (prevalences of 27.0% and 2.7%, respectively), while in I. ventalloi we found only this last species (12.5%). Moreover, Dermacentor marginatus presents R. slovaca (24.7%) and R. raoultii (59.9%). In Rhipicephalus sanguineus group ticks (Rh. sanguineus, Rh. turanicus and Rh. pusillus) only R. massiliae (15.2%) was found. Haemaphysalis punctata and Ha. sulcata were infected with a Rickettsia sp. near R. hoogstraalii (prevalence of 3.1% and 16.1%, respectively). In addition, Ha. punctata appeared infected with R. monacensis-like Rickettsia (1.0%) and R. raoultii (9.3%). None of I. hexagonus, Hyalomma lusitanicum, Hyalomma sp., Ha. hispanica or Rh. bursa studied ticks contained rickettsiae. PMID:18677442

Márquez, Francisco J

2008-08-02

206

Complete Genomic DNA Sequence of the East Asian Spotted Fever Disease Agent Rickettsia japonica.  

Science.gov (United States)

Rickettsia japonica is an obligate intracellular alphaproteobacteria that causes tick-borne Japanese spotted fever, which has spread throughout East Asia. We determined the complete genomic DNA sequence of R. japonica type strain YH (VR-1363), which consists of 1,283,087 base pairs (bp) and 971 protein-coding genes. Comparison of the genomic DNA sequence of R. japonica with other rickettsiae in the public databases showed that 2 regions (4,323 and 216 bp) were conserved in a very narrow range of Rickettsia species, and the shorter one was inserted in, and disrupted, a preexisting open reading frame (ORF). While it is unknown how the DNA sequences were acquired in R. japonica genomes, it may be a useful signature for the diagnosis of Rickettsia species. Instead of the species-specific inserted DNA sequences, rickettsial genomes contain Rickettsia-specific palindromic elements (RPEs), which are also capable of locating in preexisting ORFs. Precise alignments of protein and DNA sequences involving RPEs showed that when a gene contains an inserted DNA sequence, each rickettsial ortholog carried an inserted DNA sequence at the same locus. The sequence, ATGAC, was shown to be highly frequent and thus characteristic in certain RPEs (RPE-4, RPE-6, and RPE-7). This finding implies that RPE-4, RPE-6, and RPE-7 were derived from a common inserted DNA sequence. PMID:24039725

Matsutani, Minenosuke; Ogawa, Motohiko; Takaoka, Naohisa; Hanaoka, Nozomu; Toh, Hidehiro; Yamashita, Atsushi; Oshima, Kenshiro; Hirakawa, Hideki; Kuhara, Satoru; Suzuki, Harumi; Hattori, Masahira; Kishimoto, Toshio; Ando, Shuji; Azuma, Yoshinao; Shirai, Mutsunori

2013-09-09

207

Complete Genomic DNA Sequence of the East Asian Spotted Fever Disease Agent Rickettsia japonica  

Science.gov (United States)

Rickettsia japonica is an obligate intracellular alphaproteobacteria that causes tick-borne Japanese spotted fever, which has spread throughout East Asia. We determined the complete genomic DNA sequence of R. japonica type strain YH (VR-1363), which consists of 1,283,087 base pairs (bp) and 971 protein-coding genes. Comparison of the genomic DNA sequence of R. japonica with other rickettsiae in the public databases showed that 2 regions (4,323 and 216 bp) were conserved in a very narrow range of Rickettsia species, and the shorter one was inserted in, and disrupted, a preexisting open reading frame (ORF). While it is unknown how the DNA sequences were acquired in R. japonica genomes, it may be a useful signature for the diagnosis of Rickettsia species. Instead of the species-specific inserted DNA sequences, rickettsial genomes contain Rickettsia-specific palindromic elements (RPEs), which are also capable of locating in preexisting ORFs. Precise alignments of protein and DNA sequences involving RPEs showed that when a gene contains an inserted DNA sequence, each rickettsial ortholog carried an inserted DNA sequence at the same locus. The sequence, ATGAC, was shown to be highly frequent and thus characteristic in certain RPEs (RPE-4, RPE-6, and RPE-7). This finding implies that RPE-4, RPE-6, and RPE-7 were derived from a common inserted DNA sequence.

Matsutani, Minenosuke; Ogawa, Motohiko; Takaoka, Naohisa; Hanaoka, Nozomu; Toh, Hidehiro; Yamashita, Atsushi; Oshima, Kenshiro; Hirakawa, Hideki; Kuhara, Satoru; Suzuki, Harumi; Hattori, Masahira; Kishimoto, Toshio; Ando, Shuji; Azuma, Yoshinao; Shirai, Mutsunori

2013-01-01

208

Lysis of typhus-group rickettsia-infected targets by lymphokine activated killers  

International Nuclear Information System (INIS)

The authors recently described a subset of OKT8, OKT3-positive lymphocytes from typhus-group rickettsia immune individuals which were capable of lysing autologous PHA-blasts or Epstein-Barr virus transformed B cells (LCL) infected with typhus-group rickettsiae. In order to determine if killing by these effectors was HLA-restricted, they stimulated peripheral blood mononuclear cells (PBMC) from typhus-group rickettsia immune individuals in vitro with typhus-group rickettsia-derived antigen for one week and then measured lysis of autologous LCL or HLA-mismatched LCL in a 4-6 hour Cr51-release assay. There was significant lysis of both the autologous and the HLA-mismatched infected targets as compared to the corresponding uninfected targets. Since this suggested that the effectors were lymphokine activated killers (LAK) rather than cytotoxic T lymphocytes, they then tested this hypothesis by stimulating PBMC from both immune and non-immune individuals in vitro for one week with purified interleukin 2 and measuring lysis of infected, autologous LCL. PBMC thus treated, from both immune and non-immune individuals, were capable of significantly lysing autologous, infected LCL as compared to the non-infected control. They therefore conclude that targets infected with typhus-group rickettsiae are susceptible to lysis to LAK.

1986-01-01

209

Spotted fever group--Rickettsiae in the Tyrols: evidence by seroepidemiology and PCR.  

UK PubMed Central (United Kingdom)

The aim of our study was to assess the occurrence of Rickettsia in the inner-alpine valleys of the Eastern Alps and to determine the amount of seroreaction among the local human population. Ticks were investigated by PCR and the percentage of seropositives was determined among local blood donors by an in-house immunofluorescence assay. The local cut-off titre for screening of IgG was set at 1?:?128 with a well-characterised low-risk collective according to WHO-guidelines. Positive sera were confirmed by independent re-testing. Rickettsia is present in ticks north and south of the continental divide. Of 259 ticks investigated, 12.4% are positive for Rickettsia. Of over 1200 blood donors tested so far, 7.7% bear IgG at a titre of 1?:?128 or higher against R. helvetica. R. helvetica is present in the study area, causes immunoreaction among local residents and is associated with anamnestic erythema. Furthermore, screening with a second Spotted Fever Group Rickettsia indicates that significant parts of the Tyrolean population are exposed to a Rickettsia other than R. helvetica.

Sonnleitner ST; Simeoni J; Lang S; Dobler G; Speck S; Zelger R; Schennach H; Lass-Flörl C; Walder G

2013-06-01

210

Ganglion cells in circumscribed astrocytic tumors: possible implication in classification and prognosis/ Implicação da presença de células ganglionares na classificação e evolução de tumores astrocíticos circunscritos  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese INTRODUÇÃO: As neoplasias circunscritas incluem astrocitoma pilocítico (AP), xantoastrocitoma pleomórfico (XP) e ganglioglioma (GG), que compartilham diversas semelhanças, sendo o AP o de melhor prognóstico. Como as células ganglionares (CG) no GG podem ser escassas e os GGs podem recidivar ou evoluir (grau III), é fundamental o diagnóstico preciso. OBJETIVOS: Identificar CG e corpos granulares eosinofílicos (CGE) em AP e XP, avaliar sua implicação na evoluç? (more) ?o e comparar com o GG. MÉTODOS: Análise retrospectiva dos aspectos radiológicos, morfológicos e evolutivos (tempo livre de doença, recidiva e óbito) de 30 casos (14 AP, oito XP, oito GG). Cortes corados com hematoxilina e eosina (HE) foram revistos para a identificação da presença de CG neoplásicas e CGE. Estes foram imunomarcados para sinaptofisina (SIN) e neurofilamento (NF) e, em casos selecionados, para glial fibrillary acidic protein (GFAP). RESULTADOS: Seis AP foram reclassificados para GG pela presença de CG (HE ou imunomarcação). Alguns CGE, semelhantes às CG degeneradas, também imunomarcaram para SIN/NF, a maioria sendo negativa para GFAP. O tempo médio livre de doença foi de 62,16 meses. Quatro tumores recidivaram; um deles evoluiu para óbito. Todos os XP possuíam CG, sugerindo que são variantes de GG, dos quais quatro recidivaram (um óbito). O tempo médio livre de doença foi de 69 meses. O aspecto radiológico foi predominantemente cístico. CONCLUSÃO: Sugerimos que AP e XP com CG ou CGE imunopositivos para marcadores neuronais possam ser variantes de GG e alguns CGE representem CG degeneradas; entretanto, a presença de CG ganglionares parece não modificar o comportamento biológico dessas neoplasias. Abstract in english INTRODUCTION: Glial and neuroglial cell neoplasms comprise pilocytic astrocytoma (PA), pleomorphic xanthoastrocytoma (PXA) and ganglioglioma (GG), which share various similarities, though PA has better prognosis. As ganglion cells (GC) may be scarce in GG and these gangliogliomas may recur or progress to grade III, an accurate diagnosis is essential. OBJECTIVES: The aim was to identify GC and eosinophilic granular bodies (EGB) in PA and PXA, to evaluate its effect on pati (more) ent’s outcome and compare them with GG. METHODS: A retrospective analysis of radiological, morphological and follow-up aspects (disease free-survival, recurrence and death) of 30 cases (14 PA, 8 PXA, 8 GG). Hematoxylin and eosin (HE) stained sections were reviewed to identify the presence of neoplastic GC and EGB. They were immunostained for synaptophysin (SYN) and neurofilament (NF). Glial fibrillary acidic protein (GFAP) immunostaining was performed in selected cases. RESULTS: Six PA were reclassified as GG due to the presence of GC by HE or immunohistochemistry. Some EGB resembling degenerate GC were also immunostained for SYN/NF and most of them were negative for GFAP. The mean disease-free survival was 62.16 months. Four tumors recurred and one patient died. All PXA had GC, suggesting that they were variants of GG, 4 of which recurred and one patient died. Mean disease-free survival was 69 months. The radiological aspect was predominantly cystic. CONCLUSION: We propose that PA and PXA with GC or with EGB immunopositive for neuronal markers could be variants of GG, and some EGB may represent degenerate GC. However, the presence of GC does not seem to modify the biological behavior of these neoplasms.

Moreira, Veronica Goulart; Canedo, Nathalie Henriques Silva; Chimelli, Leila Maria Cardão

2013-06-01

211

Rickettsia 'In' and 'Out': Two Different Localization Patterns of a Bacterial Symbiont in the Same Insect Species  

Science.gov (United States)

Intracellular symbionts of arthropods have diverse influences on their hosts, and their functions generally appear to be associated with their localization within the host. The effect of localization pattern on the role of a particular symbiont cannot normally be tested since the localization pattern within hosts is generally invariant. However, in Israel, the secondary symbiont Rickettsia is unusual in that it presents two distinct localization patterns throughout development and adulthood in its whitefly host, Bemisia tabaci (B biotype). In the “scattered” pattern, Rickettsia is localized throughout the whitefly hemocoel, excluding the bacteriocytes, where the obligate symbiont Portiera aleyrodidarum and some other secondary symbionts are housed. In the “confined” pattern, Rickettsia is restricted to the bacteriocytes. We examined the effects of these patterns on Rickettsia densities, association with other symbionts (Portiera and Hamiltonella defensa inside the bacteriocytes) and on the potential for horizontal transmission to the parasitoid wasp, Eretmocerus mundus, while the wasp larvae are developing within the whitefly nymph. Sequences of four Rickettsia genes were found to be identical for both localization patterns, suggesting that they are closely related strains. However, real-time PCR analysis showed very different dynamics for the two localization types. On the first day post-adult emergence, Rickettsia densities were 21 times higher in the “confined” pattern vs. “scattered” pattern whiteflies. During adulthood, Rickettsia increased in density in the “scattered” pattern whiteflies until it reached the “confined” pattern Rickettsia density on day 21. No correlation between Rickettsia densities and Hamiltonella or Portiera densities were found for either localization pattern. Using FISH technique, we found Rickettsia in the gut of the parasitoid wasps only when they developed on whiteflies with the “scattered” pattern. The results suggest that the localization pattern of a symbiont may influence its dynamics within the host.

Caspi-Fluger, Ayelet; Inbar, Moshe; Mozes-Daube, Netta; Mouton, Laurence; Hunter, Martha S.; Zchori-Fein, Einat

2011-01-01

212

Linfadenitis por micobacterias en pediatría  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Introducción. La linfadenitis es un problema común en niños y adolescentes. Entre las causas infecciosas se encuentran las micobacterias; por lo tanto, es importante establecer el tipo prevalente de acuerdo con la epidemiología local, ya que estudios realizados en EE.UU. y Europa muestran un franco predominio de las micobacterias atípicas como causa de linfadenitis en menores de 5 años. Este estudio se realizó con el objetivo de conocer las características epidemi (more) ológicas, clínicas, microbiológicas y evolutivas de las linfadenitis por micobacterias en pediatría. Población, material y métodos. Estudio retrospectivo descriptivo realizado durante el período comprendido entre febrero de 1989 y diciembre de 2001, cuyo criterio de inclusión fueron niños con muestras ganglionares periféricas con aislamiento de micobacterias entre el primer mes mes y los 18 años de edad. Resultados. De los 29 pacientes, 70% fueron mujeres, con un rango de 7 a 228 meses (mediana: 101meses). El 70% provenía de la provincia de Buenos Aires; 24 pacientes (83%) eran huéspedes normales, 15 pacientes (52%) presentaron síntomas sistémicos. El tiempo de evolución hasta el diagnóstico tuvo una mediana de 60 días; 16 pacientes (55%) habían recibido antibióticos previamente. La linfadenopatía unilateral cervical fue la forma más común de presentación, en 22 pacientes (75%). Se halló otra localización extraganglionar en 16 (55%); la pulmonar fue la más frecuente, en 15 pacientes (94%). La PPD fue positiva en 12 (41%). La eritrosedimentación estaba acelerada en 21 (73%). Se realizó exéresis ganglionar en 23 pacientes (80%), y la punción para el diagnóstico en los 6 niños restantes. El aislamiento microbiológico se realizó a partir de muestras ganglionares exclusivas en 21 pacientes (72%) y asociadas a muestras pulmonares en 8 (27%). Se aisló Mycobacterium tuberculosis en 25 pacientes (86%), todos sensibles a tuberculostáticos de primera línea. Se halló Mycobacterium avium intracellulare en 3 de los 4 niños restantes. La evolución fue favorable en todos los casos. Conclusiones. La localización cervical unilateral fue la más frecuente. El hallazgo de Mycobacterium tuberculosis fue prevalernte, independientemente de la edad. Abstract in english Lymphadenitis is a common problem in children and adolescents. Mycobacteria are an important cause of lymphadenitis. In the USA and Europe, lymphadenitis due to atypical mycobacteria are more common in children younger than 5 years old. It is important to assess the epidemiology of mycobacterial lymphadenitis for every country. Population, material and methods. All patients admitted to the Hospital de Pediatría J.P. Garrahan from January 1989 to December 2001, between on (more) e month and 18 years of age, with lymphadenitis with positive cultures for mycobacteria were included. Results. Twenty nine patients were included. Seventy percent were female. The median age was 101 months (r: 7-228 months). 24 patients (83%) were normal hosts. Systemic syntoms were present in 15 (52%). The median time from the onset of the disease to diagnosis was 60 days. Sixteen patients had received previous antibiotics. Cervical localization was seen most frequently in 22 patients (75%). Lung involvment was detected in 15 (94%). PPD was positive in 12 (41%). VSG was accelerated in 21 patients (73%). Complete excision of the enlarged lymph node was performed in 23 patients (80%), and needle biopsy in 6. In 21 (72%), the causative Mycobacterium could be cultured in the lymph node alone. Mycobacterium tuberculosis was isolated in 25 patients (86%). All strains were sensitive to first-line drugs. Mycobacterium aviumintracellulare was isolated in 3 patients. Outcome was good in all cases. Conclusions. Cervical localization was the most frequent. Mycobacterium tuberculosis was the most common pathogen in all ages.

Berberian, Griselda; Santillán Iturrez, Alejandro; Casimir, Lidia; Rosanova, María Teresa

2005-02-01

213

Rickettsia africae in Hyalomma dromedarii ticks from sub-Saharan Algeria.  

UK PubMed Central (United Kingdom)

Spotted fever group (SFG) rickettsioses are caused by obligate, intracellular Gram-negative bacteria of the genus Rickettsia. In recent years, several species and subspecies of rickettsias have been identified as emerging pathogens throughout the world, including sub-Saharan Africa. We report here the detection of Rickettsia africae, the agent responsible for African tick-bite fever, by amplification of fragments of gltA and ompA genes and multi-spacer typing from Hyalomma dromedarii ticks collected from the camel Camelus dromedarius in the Adrar and Béchar region (sub-Saharan Algeria). To date, R. africae has been associated mainly with Amblyomma spp. The role of H. dromedarii in the epidemiology of R. africae requires further investigation.

Kernif T; Djerbouh A; Mediannikov O; Ayach B; Rolain JM; Raoult D; Parola P; Bitam I

2012-12-01

214

Epizootiology of epidemic typhus (Rickettsia prowazekii) in flying squirrels.  

Science.gov (United States)

Vector transmission of Rickettsia prowazekii among wild flying squirrels, Glaucomys volans, was suggested by the occurrence of natural infection of squirrel lice and fleas. Lice, mostly Neohaematopinus sciuropteri Osburn, were found infected in the fall in each of 2 consecutive years; 4 of the 8 pools of this insect tested were infected. Fleas, Orchopeas howardii (Baker), were found infected on two occasions in 1 of the 2 consecutive years. However, only 2 of 14 flea pools were infected. No evidence of infection was found in mites, Haemogamasus reidi Ewing and Androlaelaps fahrenholzi (Berlese). These findings implicate the flying squirrel louse and flea as possible vectors in nature. Serologic tests of flying squirrel sera revealed a maximum incidence of seroconversions in the fall and early winter months, coincident with the maximum increase in abundance of the suspected arthropod vectors. The infection was found to persist form year to year in the same enzootic foci. Infection appeared to spread most rapidly in young, non-immune animals born in the preceding spring and summer after congregating in dense aggregations in the fall. No other animals in the same habitat were found to have been infected. Aspects of the ecology of the ectoparasites associated with the flying squirrels are described, especially seasonal activity and abundance in nests. The potential public health importance of this sylvan disease in flying squirrels and in its ectoparasites, particularly the non-host specific, wide ranging squirrel flea, is noted. PMID:646026

Sonenshine, D E; Bozeman, F M; Williams, M S; Masiello, S A; Chadwick, D P; Stocks, N I; Lauer, D M; Elisberg, B L

1978-03-01

215

Epizootiology of epidemic typhus (Rickettsia prowazekii) in flying squirrels.  

UK PubMed Central (United Kingdom)

Vector transmission of Rickettsia prowazekii among wild flying squirrels, Glaucomys volans, was suggested by the occurrence of natural infection of squirrel lice and fleas. Lice, mostly Neohaematopinus sciuropteri Osburn, were found infected in the fall in each of 2 consecutive years; 4 of the 8 pools of this insect tested were infected. Fleas, Orchopeas howardii (Baker), were found infected on two occasions in 1 of the 2 consecutive years. However, only 2 of 14 flea pools were infected. No evidence of infection was found in mites, Haemogamasus reidi Ewing and Androlaelaps fahrenholzi (Berlese). These findings implicate the flying squirrel louse and flea as possible vectors in nature. Serologic tests of flying squirrel sera revealed a maximum incidence of seroconversions in the fall and early winter months, coincident with the maximum increase in abundance of the suspected arthropod vectors. The infection was found to persist form year to year in the same enzootic foci. Infection appeared to spread most rapidly in young, non-immune animals born in the preceding spring and summer after congregating in dense aggregations in the fall. No other animals in the same habitat were found to have been infected. Aspects of the ecology of the ectoparasites associated with the flying squirrels are described, especially seasonal activity and abundance in nests. The potential public health importance of this sylvan disease in flying squirrels and in its ectoparasites, particularly the non-host specific, wide ranging squirrel flea, is noted.

Sonenshine DE; Bozeman FM; Williams MS; Masiello SA; Chadwick DP; Stocks NI; Lauer DM; Elisberg BL

1978-03-01

216

Tick cell culture isolation and growth of Rickettsia raoultii from Dutch Dermacentor reticulatus ticks.  

UK PubMed Central (United Kingdom)

Tick cell lines play an important role in research on ticks and tick-borne pathogenic and symbiotic microorganisms. In an attempt to derive continuous Dermacentor reticulatus cell lines, embryo-derived primary cell cultures were set up from eggs laid by field ticks originally collected as unfed adults in The Netherlands and maintained for up to 16 months. After several months, it became evident that cells in the primary cultures were infected with a Rickettsia-like intracellular organism. Supernatant medium containing some D. reticulatus cells was inoculated into cultures of 2 Rhipicephalus (Boophilus) microplus cell lines, BME/CTVM2 and BME/CTVM23, where abundant growth of the bacteria occurred intracellularly on transfer to both cell lines. Bacterial growth was monitored by light (live, inverted microscope, Giemsa-stained cytocentrifuge smears) and transmission electron microscopy revealing heavy infection with typical intracytoplasmic Rickettsia-like bacteria, not present in uninfected cultures. DNA was extracted from bacteria-infected and uninfected control cultures, and primers specific for Rickettsia 16S rRNA, ompB, and sca4 genes were used to generate PCR products that were subsequently sequenced. D. reticulatus primary cultures and both infected tick cell lines were positive for all 3 Rickettsia genes. Sequencing of PCR products revealed 99-100% identity with published Rickettsia raoultii sequences. The R. raoultii also grew abundantly in the D. nitens cell line ANE58, poorly in the D. albipictus cell line DALBE3, and not at all in the D. andersoni cell line DAE15. In conclusion, primary tick cell cultures and cell lines are useful systems for isolation and propagation of fastidious tick-borne microorganisms. In vitro isolation of R. raoultii from Dutch D. reticulatus confirms previous PCR-based detection in field ticks, and presence of the bacteria in the tick eggs used to initiate the primary cultures confirms that transovarial transmission of this Rickettsia occurs.

Alberdi MP; Nijhof AM; Jongejan F; Bell-Sakyi L

2012-12-01

217

Rickettsia hoogstraalii sp. nov., isolated from hard- and soft-bodied ticks.  

Science.gov (United States)

A novel spotted fever group Rickettsia was found in Haemaphysalis sulcata ticks collected from sheep and goats in Croatia in 2006. At the same time, a genetically identical organism was co-isolated with the embryonic cell line CCE3 obtained from the soft tick Carios capensis in Georgia, USA. In this study, further phenotypic and genotypic characteristics of the novel rickettsial strain present in H. sulcata ticks were investigated. Based on the cultivation of bacteria in mosquito and Vero cell cultures, the presence of rickettsiae in tick tissues and cell cultures [confirmed by transmission electron microscopy (TEM)] and the amplification and sequencing of five rickettsial genes, it was demonstrated that the novel Rickettsia strain fulfils the criteria to be classified as a novel species. The name Rickettsia hoogstraalii sp. nov. is proposed for the new strain. Rickettsia hoogstraalii sp. nov., an obligately intracellular bacterium, was grown in Vero cells and arthropod CCE3, ISE6 and C6/36 cell lines. The morphology of the cells of the novel species was typical of SFG rickettsiae. The small coccobacillary appearance of the bacteria was apparent with light microscopy. A Gram-negative bacterial cell wall and a cytoplasmic membrane separated by a narrow periplasmic space were visible by TEM. To date, Rickettsia hoogstraalii sp. nov. has been isolated from two species of ticks, H. sulcata and C. capensis. The novel species appears to be geographically widely distributed, having been detected in Croatia, Spain and Georgia, USA. Although no information is available regarding the possible pathogenicity of the novel species for vertebrate hosts, R. hoogstraalii sp. nov. has a cytopathic effect in Vero, CCE3 and ISE6 cells. Sequence analyses of the 16S rRNA, 17 kDa, gltA, ompA and ompB genes indicated that even though R. hoogstraalii sp. nov. was closely related to Rickettsia felis, it represents a separate species within the spotted fever group. The type strain of R. hoogstraalii sp. nov. is strain Croatica(T) (=DSM 22243(T)=UTMB 00003(T)). PMID:19666817

Duh, Darja; Punda-Polic, Volga; Avsic-Zupanc, Tatjana; Bouyer, Donald; Walker, David H; Popov, Vsevolod L; Jelovsek, Mateja; Gracner, Maja; Trilar, Tomi; Bradaric, Nikola; Kurtti, Timothy J; Strus, Jasna

2009-08-07

218

Rickettsia hoogstraalii sp. nov., isolated from hard- and soft-bodied ticks.  

UK PubMed Central (United Kingdom)

A novel spotted fever group Rickettsia was found in Haemaphysalis sulcata ticks collected from sheep and goats in Croatia in 2006. At the same time, a genetically identical organism was co-isolated with the embryonic cell line CCE3 obtained from the soft tick Carios capensis in Georgia, USA. In this study, further phenotypic and genotypic characteristics of the novel rickettsial strain present in H. sulcata ticks were investigated. Based on the cultivation of bacteria in mosquito and Vero cell cultures, the presence of rickettsiae in tick tissues and cell cultures [confirmed by transmission electron microscopy (TEM)] and the amplification and sequencing of five rickettsial genes, it was demonstrated that the novel Rickettsia strain fulfils the criteria to be classified as a novel species. The name Rickettsia hoogstraalii sp. nov. is proposed for the new strain. Rickettsia hoogstraalii sp. nov., an obligately intracellular bacterium, was grown in Vero cells and arthropod CCE3, ISE6 and C6/36 cell lines. The morphology of the cells of the novel species was typical of SFG rickettsiae. The small coccobacillary appearance of the bacteria was apparent with light microscopy. A Gram-negative bacterial cell wall and a cytoplasmic membrane separated by a narrow periplasmic space were visible by TEM. To date, Rickettsia hoogstraalii sp. nov. has been isolated from two species of ticks, H. sulcata and C. capensis. The novel species appears to be geographically widely distributed, having been detected in Croatia, Spain and Georgia, USA. Although no information is available regarding the possible pathogenicity of the novel species for vertebrate hosts, R. hoogstraalii sp. nov. has a cytopathic effect in Vero, CCE3 and ISE6 cells. Sequence analyses of the 16S rRNA, 17 kDa, gltA, ompA and ompB genes indicated that even though R. hoogstraalii sp. nov. was closely related to Rickettsia felis, it represents a separate species within the spotted fever group. The type strain of R. hoogstraalii sp. nov. is strain Croatica(T) (=DSM 22243(T)=UTMB 00003(T)).

Duh D; Punda-Polic V; Avsic-Zupanc T; Bouyer D; Walker DH; Popov VL; Jelovsek M; Gracner M; Trilar T; Bradaric N; Kurtti TJ; Strus J

2010-04-01

219

Molecular evidence of Rickettsia felis infection in dogs from northern territory, Australia  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract The prevalence of spotted fever group rickettsial infection in dogs from a remote indigenous community in the Northern Territory (NT) was determined using molecular tools. Blood samples collected from 130 dogs in the community of Maningrida were subjected to a spotted fever group (SFG)-specific PCR targeting the ompB gene followed by a Rickettsia felis-specific PCR targeting the gltA gene of R. felis. Rickettsia felis ompB and gltA genes were amplified from the blood of 3 dogs. This study is the first report of R. felis infection in indigenous community dogs in NT.

Hii Sze-Fui; Kopp Steven R; Thompson Mary F; O'Leary Caroline A; Rees Robert L; Traub Rebecca J

2011-01-01

220

Detection of Rickettsia massiliae in Rhipicephalus sanguineus from the eastern United States.  

UK PubMed Central (United Kingdom)

We report the first evidence of Rickettsia massiliae in the brown dog tick, Rhipicephalus sanguineus, from the East Coast of the United States. As part of routine pathogen surveillance, DNA samples from ixodid ticks were tested for spotted fever group rickettsiae by nested PCR. A R. massiliae-positive tick was collected off a beagle mix recently rescued from North Carolina. Infection was confirmed by partial sequence analysis of the htrA, gltA, ompB, ompA, and sca4 genes, which had 100% identity to a R. massiliae isolate from Arizona.

Fornadel CM; Smith JD; Zawada SE; Arias JR; Norris DE

2013-01-01

 
 
 
 
221

Genomic study of Rickettsia akari by pulsed-field gel electrophoresis.  

UK PubMed Central (United Kingdom)

Pulsed-field gel electrophoresis of SmaI-, EagI-, and BssHII-digested DNA was used to perform restriction fragment length polymorphism analysis of Rickettsia akari strains isolated from humans, rodents, and mites in the United States and Ukraine. Although some differences in biological and serological characteristics were present between strains, the genomic studies demonstrated a high degree of intraspecies homogeneity of R. akari isolates. Our results confirm the value of pulsed-field gel electrophoresis-restriction fragment length polymorphism analysis for the identification of species of rickettsiae.

Eremeeva M; Balayeva N; Ignatovich V; Raoult D

1995-11-01

222

Description of "yaaf", the vesicular fever caused by acute Rickettsia felis infection in Senegal.  

UK PubMed Central (United Kingdom)

Rickettsiosis caused by Rickettsia felis is an emerging infection in Africa and may account for 3-4% of ambulatory febrile fevers. We report herein a case of R. felis infection, for which we propose the name "yaaf", meaning vesicle, in an 8-month-old girl who was diagnosed in the field by real-time PCR analysis of a skin lesion; these PCR analysis was performed at a local experimental point-of-care laboratory. The clinical presentation was polymorphous skin lesions, including papules, vesicles, erosions and ulcers. The patient did not produce antibodies against Rickettsia. We suggest that this disease may be a primary infection caused by R. felis.

Mediannikov O; Fenollar F; Bassene H; Tall A; Sokhna C; Trape JF; Raoult D

2013-06-01

223

New perspectives on rickettsial evolution from new genome sequences of rickettsia, particularly R. canadensis, and Orientia tsutsugamushi.  

UK PubMed Central (United Kingdom)

The complete genome sequences available for eight species of Rickettsia and information for other near relatives in the Rickettsiales including Orientia and species of Anaplasmataceae are a rich resource for comparative analyses of the evolution of these obligate intracellular bacteria. Differences in these organisms have permitted them to colonize varied intracellular compartments, arthropod vectors, and vertebrate reservoirs in both pathogenic and symbiotic relationships. We summarize some comparative aspects of the genomes of these organisms, paying particular attention to the recently completed sequence for R. canadensis McKiel strain and an estimated two-thirds of the genome sequence for a Thailand patient isolate of Orientia tsutsugamushi. The Rickettsia genomes exhibit a high degree of synteny punctuated by distinctive chromosome inversions and consistent phylogenetic relationships regardless of whether protein coding sequences or RNA genes, concatenated open reading frames or gene regions, or whole genomes are used to construct phylogenetic trees. The aggregate characteristics (number, length, composition, repeat identity) of tandem repeat sequences of Rickettsia, which often exhibit recent and rapid divergence between closely related strains and species of bacteria, are also very conserved in Rickettsia but differed significantly in Orientia. O. tsutsugamushi shared no significant synteny to species of Rickettsia or Anaplasmataceae, supporting its placement in a unique genus. Like Rickettsia felis, Orientia has many transposases and ankyrin and tetratricopeptide repeat domains. Orientia shares the important ATP/ADP translocase and proline-betaine transporter multigene families with Rickettsia, but has more gene families that may be involved in regulatory and transporter responses to environmental stimuli.

Eremeeva ME; Madan A; Shaw CD; Tang K; Dasch GA

2005-12-01

224

Evidence of spotted fever group rickettsiae in state of Rio de Janeiro, Brazil/ Evidência de rickettsiae do grupo da febre maculosa no Estado do Rio de Janeiro, Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese De fevereiro a setembro de 1999, foram realizadas, semanalmente, coletas de carrapatos de cães no Município de Piraí/RJ. Quatrocentos e setenta e quatro ixodídeos foram taxonomicamente identificados, 103 Amblyomma cajennense, sete Amblyomma ovale, 209 Rhipicephalus sanguineus e 155 Amblyomma sp. O teste de hemolinfa associado à coloração de Giemsa revelou que duas espécies de 163 carrapatos testados (R. sanguineus e A. sp.) continham microrganismos com morfologia (more) semelhante à rickettsia do grupo da febre maculosa. No teste de imunofluorescência direta, mais específico, foi verificada a presença de rickettsia do grupo da febre maculosa em uma espécie de R. sanguineus. Considerando que informações sobre rickettsioses no Brasil são limitadas, principalmente com relação aos vetores envolvidos na perpetuação da doença, estes resultados preliminares nos mostram a necessidade da realização deste tipo de estudo, permitindo, desta forma, aumentar nossos conhecimentos a respeito desta zoonose. Abstract in english Ticks were obtained from dogs from February to September of 1999 at weekly intervals, in the County of Piraí, State of Rio de Janeiro. Four hundred seventy four ixodids were taxonomically identified, 103 Amblyomma cajennense, seven Amblyomma ovale, 209 Rhipicephalus sanguineus, and 155 Amblyomma sp. An hemolymph test associated with Giemsa's stain revealed two specimens in 163 ticks tested (R. sanguineus and Amblyomma sp), containing rickettsia-like organisms. Direct imm (more) unofluorescence verified the presence of spotted fever group rickettsia in one specimen of R. sanguineus. Considering the limited information on rickettsiosis in Brazil, principally in relation to the vectors involved in perpetuating it in foci, these preliminary results give us an idea on the importance of infection in ticks, allowing to expand our knowledge on this zoonosis.

ROZENTAL, Tatiana; BUSTAMANTE, Maria Cristina; AMORIM, Marinete; SERRA-FREIRE, Nicolau Maués; LEMOS, Elba Regina Sampaio de

2002-01-01

225

Structural features of lipid A of Rickettsia typhi.  

UK PubMed Central (United Kingdom)

Lipid A isolated from the Rickettsia typhi lipopolysaccharide (LPS) was investigated for its composition and structure using chemical analyses, gas chromatography-mass spectrometry (GC-MS), and electrospray ionization (ESI) combined with the tandem mass spectrometry (MS/MS). Our studies revealed a noticeable compositional and structural heterogeneity of lipid A with respect to the content of phosphate groups and the degree of acylation. It appeared that at least two molecular species were present in lipid A. The major species represented the hexaacyl lipid A consisting of the ?-(1--> 6)-linked D-glucosamine (GlcN) disaccharide backbone carrying two phosphate groups. One of them was linked to the glycosidic hydroxyl group of the reducing GlcN I and the other was ester linked to the O-4´ position of the non-reducing GlcN II. The primary fatty acids consisted of two 3-hydroxytetradecanoic [C14:0(3-OH)] and two 3-hydroxyhexadecanoic [C16:0(3-OH)] acids. The former were ester- and the latter amide-linked to both GlcN. Two secondary fatty acids were represented by the octadecanoic (C18:0) and hexadecanoic (C16:0) acids that were ester-linked at the N-2´ and O-3´ positions, respectively. In the minor lipid A species, ester-linked C18:0 was substituted by C16:0 at the C16:0(3-OH) of GlcN II. The R. typhi lipid A resembles structurally the classical forms of enterobacterial lipids A with high endotoxicity.

Fodorová M; Vadovi? P; Toman R

2011-01-01

226

Índice ganglionar y número de linfonodos metastásicos como factores pronósticos en cáncer de colon/ Lymph node index as a prognostic factor for survival in stage III colon cancer  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Introducción: El índice ganglionar (IG) se ha propuesto como un factor pronóstico mejor que el número de LN positivos en cáncer de colon estadio III. El objetivo es comparar estos factores en una serie clínica. Pacientes y Método: Se incluyen todos los pacientes estadio III resecados con intención curativa (R0). Se compara la sobrevida según el número de LN positivos y el IG mediante el análisis de las curvas ROC. Resultados: Se trata de 115 pacientes con un pr (more) omedio de edad de 67,9 años (extremos 25-91), el 63,4% mujeres. El compromiso en profundidad del tumor fue T2 en 3 casos, T3 en 93 casos y T4 en 19. El promedio de ganglios positivos fue 3,4 (extremos 1-34). El índice ganglionar promedio fue 0,237 (DE: 0,197; extremos 0,031-0,882) y la mediana fue 0,1666. El 74% de los pacientes tenía 1 a 3 ganglios positivos (N1) y el 26% 4 o más ganglios positivos (N2). El seguimiento promedio fue de 67 meses (extremos 5-216), durante el cual fallecen 29 pacientes. El área bajo la curva ROC del número de LN afectados (0,703; IC 95%:0,58-082) fue levemente mayor que el área bajo la curva ROC del IG (0,690; IC 95%:0,57-0,81) (p = 0,63). Al compararlas en forma dicotómica, el IG (OR: 19,96; IC 95%:1,51-253,6) muestra una mayor capacidad de discriminación que el número de LN afectados (OR: 2,55; IC 95%: 0,86-7,55). Conclusión: El número de LN metastásicos y el IG son factores pronósticos relevantes en la planificación de la adyuvancia del cáncer de colon estadio III. Abstract in english Background: The lymph node ratio in malignant tumors corresponds to the ratio between the number of involved lymph nodes and the number of examined lymph nodes. This ratio may be a good prognostic index in stage III colon cancer. Aim: To compare the lymph node ratio with the absolute number of positive lymph nodes as prognostic factors in stage III colon cancer. Material and Methods: Analysis of 115 patients aged 25 to 91 years (63% women) with a stage III colon cancer op (more) erated between 1991 and 2007. Survival according to the absolute number of positive lymph nodes and the lymph node index was calculated. The area under receiver operating characteristic (ROC) curves obtained after a COX regression analysis of survival, was used to analyze the prognostic value of each parameter. Results: Lymph node involvement was classified as T2 in three, T3 in 93 and T4 in 19 patients. The mean number of positive lymph nodes was 3.4 (range 1 to 34) and the mean lymph node index was 0.237 ± 0.197 (range 0.031-0.882). Seventy four percent of patients had one to three positive lymph nodes and 24% had more than three. During a mean follow up of 67 months (range 5-216), 29 patients died. In survival analysis, the area under the ROC curve for the number of involved lymph nodes (0.703, 95 confidence intervals (CI) 0.58-0.82) was slightly better than the area for lymph node index (0.69, 95% CI 0.57-0.81). Using a dichotomy analysis, a lymph node index over 0.31 had a higher discriminating value for survival (odds ratio (OR) 19.96 91% CI 1.51-253.6) than the presence of 12 or more involved lymph nodes (OR 2.55 95% CI 0.86-7.55). Conclusions: The lymph node index and the absolute number of involved lymph nodes are prognostic factors in stage III colon cancer.

BANNURA C, GUILLERMO; VARGAS S, CLAUDIO; BARRERA E, ALEJANDRO; MELO L, CARLOS; CONTRERAS P, JAIME

2011-10-01

227

Rickettsia infection in five areas of the state of São Paulo, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available This study investigated rickettsial infection in animals, humans, ticks, and fleas collected in five areas of the state of São Paulo. Eight flea species (Adoratopsylla antiquorum antiquorum, Ctenocephalides felis felis, Polygenis atopus, Polygenis rimatus, Polygenis roberti roberti, Polygenis tripus, Rhopalopsyllus lugubris, and Rhopalopsyllus lutzi lutzi), and five tick species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Ixodes loricatus, and Rhipicephalus sanguineus) were collected from dogs, cats, and opossums. Rickettsia felis was the only rickettsia found infecting fleas, whereas Rickettsia bellii was the only agent infecting ticks, but no animal or human blood was shown to contain rickettsial DNA. Testing animal and human sera by indirect immunofluorescence assay against four rickettsia antigens (R. rickettsii, R. parkeri, R. felis, and R. bellii), some opossum, dog, horse, and human sera reacted to R. rickettsii with titers at least four-fold higher than to the other three rickettsial antigens. These sera were considered to have a predominant antibody response to R. rickettsii. Using the same criteria, opossum, dog, and horse sera showed predominant antibody response to R. parkeri or a very closely related genotype. Our serological results suggest that both R. rickettsii and R. parkeri infected animals and/or humans in the studied areas.

Maurício C Horta; Marcelo B Labruna; Adriano Pinter; Pedro M Linardi; Teresinha T S Schumaker

2007-01-01

228

Morphological evidence for infection of impala, Aepyceros melampus, platelets by a rickettsia-like organism.  

UK PubMed Central (United Kingdom)

Ultrastructural studies revealed the presence of a parasite, believed to be Ehrlichia platys, in the blood platelets of impala. At the time of blood sampling all the animals appeared healthy. This is the first report on the presence of this rickettsia in these animals, previously described in canine platelets.

Du Plessis L; Reyers F; Stevens K

1997-12-01

229

Detection of Point Mutations in rpoB Gene of Rifampin-Resistant Rickettsia typhi  

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The rpoB gene of rifampin-resistant Rickettsia typhi (Rif mutant) and wild-type R. typhi were sequenced and compared. The Rif mutant rpoB had three nucleotide substitutions, which resulted in amino acid changes at residues 151, 201, and 271 and may be the basis for the rifampin resistance.

Troyer, Jill Michelle; Radulovic, Suzana; Andersson, Siv G. E.; Azad, Abdu F.

230

SPOTTED FEVER : I. INTRANUCLEAR RICKETTSIAE IN SPOTTED FEVER STUDIED IN TISSUE CULTURE  

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Spotted fever infection has been studied in tissue cultures grown at 32°C. The behavior of spotted fever Rickettsiaeis compared and contrasted with that of typhus Rickettsiae under similar conditions. The spotted fever organisms multiply extensively in the nuclei of cells where they form spherical ...

Pinkerton, Henry; Hass, G. M.

231

Tick infestation and spotted-fever group Rickettsia in shelter dogs, California, 2009.  

UK PubMed Central (United Kingdom)

In response to an outbreak of Rocky Mountain spotted fever (RMSF) in Baja California in early 2009, dogs at two shelters in neighbouring Imperial County, California, were evaluated for ectoparasites. Brown dog ticks (Rhipicephalus sanguineus), a recognized vector for RMSF, were found on 35 (30%) of 116 dogs but all ticks tested negative for Rickettsia rickettsii by PCR.

Fritz CL; Kriner P; Garcia D; Padgett KA; Espinosa A; Chase R; Hu R; Messenger SL

2012-02-01

232

Rickettsia rickettsii (Rickettsiales: Rickettsiaceae) in Amblyomma americanum (Acari: Ixodidae) from Kansas.  

UK PubMed Central (United Kingdom)

The role of lone star ticks as vectors for Rocky Mountain spotted fever (RMSF) remains poorly described. We compared the entomological inoculation rates (EIRs) for Rickettsia spp. for representative sites in Missouri and Kansas, states that frequently report RMSF each year. Host-seeking ticks were collected during 2006 and pooled tick homogenates analyzed by polymerase chain reaction to detect probable R. rickettsii, with confirmation for multiple gene targets performed on individual ticks from pools that screened positive. Of 870 adult and nymphal lone star ticks, Amblyomma americanum (L.), 0.46% contained DNA of Rickettsia rickettsii. Interestingly, two of these positive ticks were concurrently infected by R. amblyommii. More than 90% of lone star tick pools contained R. amblyommii DNA. Of 169 dog ticks that were analyzed, none were infected by R. rickettsii. The entomological inoculation rate for spotted fever group (SFG) rickettsiae within lone star ticks was an order of magnitude greater than that for dog ticks. We conclude that lone star ticks may be epidemiologically significant vectors of Rocky Mountain spotted fever and of spotted fever group rickettsiae.

Berrada ZL; Goethert HK; Cunningham J; Telford SR 3rd

2011-03-01

233

Rickettsia parkeri in Amblyomma maculatum ticks, North Carolina, USA, 2009-2010.  

UK PubMed Central (United Kingdom)

We detected Rickettsia parkeri in 20%-33% of Amblyomma maculatum ticks sampled in North Carolina. Results highlight the high frequencies of R. parkeri-infected ticks in the state with the highest annual incidence of Rocky Mountain spotted fever. Epidemiologic studies are needed to definitively link R. parkeri to cases of spotted fever rickettsiosis.

Varela-Stokes AS; Paddock CD; Engber B; Toliver M

2011-12-01

234

Adherence to and invasion of host cells by spotted Fever group rickettsia species.  

UK PubMed Central (United Kingdom)

The pathogenic lifecycle of obligate intracellular bacteria presents a superb opportunity to develop understanding of the interaction between the bacteria and host under the pretext that disruption of these processes will likely lead to death of the pathogen and prevention of associated disease. Species of the genus Rickettsia contain some of the most hazardous of the obligate intracellular bacteria, including Rickettsia rickettsii and R. conorii the causative agents of Rocky Mountain and Mediterranean spotted fevers, respectively. Spotted fever group Rickettsia species commonly invade and thrive within cells of the host circulatory system whereby the endothelial cells are severely perturbed. The subsequent disruption of circulatory continuity results in much of the severe morbidity and mortality associated with these diseases, including macropapular dermal rash, interstitial pneumonia, acute renal failure, pulmonary edema, and other multisystem manifestations. This review describes current knowledge of the essential pathogenic processes of adherence to and invasion of host cells, efforts to disrupt these processes, and potential for disease prevention through vaccination with recently identified bacterial adherence and invasion proteins. A more complete understanding of these bacterial proteins will provide an opportunity for prevention and treatment of spotted fever group Rickettsia infections.

Chan YG; Riley SP; Martinez JJ

2010-01-01

235

Origin and Structure of the Group-Specific, Complement-Fixing Antigen of Rickettsia rickettsii  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rickettsia rickettsii was treated with ether and examined by negative-contrast electron microscopy. Group-specific complement-fixing antigen was seen to be originating from the cell wall. The antigen was composed predominately of round particles 10 to 60 nm in diameter. Intact R. rickettsii and anti...

Tzianabos, T.; Palmer, E. L.; Obijeski, J. F.; Martin, M. L.

236

Rickettsia typhi and R. felis in Rat Fleas (Xenopsylla cheopis), Oahu, Hawaii  

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Rickettsia typhi (prevalence 1.9%) and R. felis (prevalence 24.8%) DNA were detected in rat fleas (Xenopsylla cheopis) collected from mice on Oahu Island, Hawaii. The low prevalence of R. typhi on Oahu suggests that R. felis may be a more common cause of rickettsiosis than R. typhi in Hawaii.

Eremeeva, Marina E.; Warashina, Wesley R.; Sturgeon, Michele M.; Buchholz, Arlene E.; Olmsted, Gregory K.; Park, Sarah Y.

237

Genetic characterization and transovarial transmission of a typhus-like rickettsia found in cat fleas.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The identification of apparently fastidious microorganisms is often problematic. DNA from a rickettsia-like agent (called the ELB agent) present in cat fleas could be amplified by PCR with conserved primers derived from rickettsial 17-kDa common protein antigen and citrate synthase genes but not spo...

Azad, A F; Sacci, J B; Nelson, W M; Dasch, G A; Schmidtmann, E T; Carl, M

238

Phospholipase A Activity in the Hemolysis of Sheep and Human Erythrocytes by Rickettsia prowazeki  

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Incubation of Rickettsia prowazeki with sheep or human erythrocytes resulted in lysis of the erythrocytes and formation of free fatty acids and lysophosphatides. Inhibitors of lysis were also invariably inhibitors of this phospholipase A activity. The target for this activity was the glycerophosphol...

Winkler, Herbert H.; Miller, Elizabeth T.

239

Comparison of the Ultrastructure of Several Rickettsiae, Ornithosis Virus, and Mycoplasma in Tissue Culture  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Anderson, Douglas R. (National Cancer Institute, Bethesda, Md.), Hope E. Hopps, Michael F. Barile, and Barbara C. Bernheim. Comparison of the ultrastructure of several rickettsiae, ornithosis virus, and Mycoplasma in tissue culture. J. Bacteriol. 90:1387–1404. 1965.—In an effort to make a valid comp...

Anderson, Douglas R.; Hopps, Hope E.; Barile, Michael F.; Bernheim, Barbara C.

240

Detecção de riquétsias em carrapatos do gênero Amblyomma (Acari: Ixodidae) coletados em parque urbano do município de Campinas, SP/ Rickettsiae detection in Amblyomma ticks (Acari: Ixodidae) collected in the urban area of Campinas city, SP  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O Município de Campinas situa-se em região endêmica para febre maculosa brasileira do Estado de São Paulo, onde vários casos desta doença vem ocorrendo. Capivaras têm sido associadas ao ciclo dessa riquetsiose por apresentarem sorologia positiva e serem hospedeiras de carrapatos Amblyomma spp principais vetores da doença. Carrapatos foram coletados no parque urbano do Lago do Café, Campinas, SP, local associado a casos humanos suspeitos de febre maculosa brasilei (more) ra, sobre a vegetação e das capivaras ali presentes, e pesquisados quanto à presença de riquétsias pela reação em cadeia da polimerase e pelo teste de hemolinfa. Adultos de Amblyomma cajennense e Amblyomma cooperi albergavam Rickettsia bellii, não patogênica, identificada pela análise das seqüências de nucleotídeos do gene gltA, porém, não foram constatadas riquétsias do Grupo da Febre Maculosa. Estes resultados associados à ausência de um isolado de riquétsias do Grupo da Febre Maculosa de capivaras indicam que seu papel, enquanto reservatório, necessita de maior investigação. Abstract in english The city of Campinas is located in an endemic area for brazilian spotted fever in São Paulo State, where several cases have recently occurred. Capybaras have been associated with the cycle of this disease, for they present positive serology and serve as host for ticks of the genus Amblyomma, the main vectors of brazilian spotted fever. Ticks were colleted both from Capybaras and from the vegetation in the city park Lago do Café, located in the urban area of Campinas cit (more) y, SP, a site associated with suspected human cases of brazilian spotted fever. The ticks collected were examinaded for the presence of rickettsiae using polymerase chain reaction and the haemolymph test. Through analysis of the gene gltA nucleotide sequence, adults of Amblyomma cajennense and Amblyomma cooperi were found to be infected with the non pathogenic Rickettsia bellii. However, no rickettsiae of the spotted fever group were detected. These results indicate that the role of capybaras as reservoirs of rickettsiae of the Spotted Fever group is still uncertain and further studies are required.

Estrada, Dora Amparo; Schumaker, Teresinha Tizu Sato; Souza, Celso Eduardo de; Rodrigues Neto, Elias José; Linhares, Arício Xavier

2006-02-01

 
 
 
 
241

Pesquisa de Rickettsia spp em carrapatos Amblyomma cajennense e Amblyomma dubitatum no Estado de São Paulo/ Survey of Rickettsia spp in the ticks Amblyomma cajennense and Amblyomma dubitatum in the State of São Paulo  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Foi pesquisada a presença de riquétsias em 3.545 carrapatos Amblyomma cajennense e 2.666 Amblyomma dubitatum. Através do teste de hemolinfa, reação em cadeia pela polimerase e isolamento de rickettsia em cultivo celular, todos os Amblyomma cajennense foram negativos, sendo que 634 (23,8%) Amblyomma dubitatum mostraram-se infectados com Rickettsia bellii. Abstract in english The presence of rickettsial infection was surveyed in 3,545 Amblyomma cajennense ticks and 2,666 Amblyomma dubitatum ticks. Using the hemolymph test, polymerase chain reaction and isolation of Rickettsia in cell cultures, all of the Amblyomma cajennense were negative, whereas 634 (23.8%) of the Amblyomma dubitatum ticks were shown to be infected with Rickettsia bellii.

Pacheco, Richard Campos; Horta, Maurício Cláudio; Pinter, Adriano; Moraes-Filho, Jonas; Martins, Thiago Fernandes; Nardi, Marcello Schiavo; Souza, Savina Silvana Aparecida Lacerra de; Souza, Celso Eduardo de; Szabó, Matias Pablo Juan; Richtzenhain, Leonardo José; Labruna, Marcelo Bahia

2009-06-01

242

Rickettsia 364D: a newly recognized cause of eschar-associated illness in California.  

UK PubMed Central (United Kingdom)

BACKGROUND: Four spotted fever group rickettsiae (SFGR) are known to infect humans in the United States. A member of the SFGR designated 364D and detected in Dermacentor occidentalis ticks has not previously been identified as a human pathogen. METHODS: An 80-year-old man from a rural northern California community presented with an eschar on his forearm. A skin punch biopsy of the lesion was evaluated by immunohistochemistry and molecular analysis. Serum specimens obtained from the patient and 3 other area residents with similar illnesses were tested by immunofluorescence and Western immunoblot for antibodies to SFGR. Ticks were collected near the patient's residence and tested for SFGR. RESULTS: Abundant intracellular rickettsiae and fragmented rickettsial antigens were observed in the mononuclear inflammatory infiltrates of the biopsy. Nucleotide sequences of DNA fragments amplified from the biopsy were identical to those of 364D. Convalescent sera from all four patients exhibited high immunoglobulin G titers to Rickettsia rickettsii, Rickettsia rhipicephali, and 364D antigens. Three adult D. occidentalis were positive for 364D, R. rhipicephali, and an unidentified Rickettsia species. CONCLUSIONS: This is the first confirmation of human disease associated with the SFGR 364D, which was likely transmitted by D. occidentalis. Although the patients described here presented with a single cutaneous eschar as the principal manifestation, the full spectrum of illness associated with 364D has yet to be determined. Possible infection with 364D or other SFGR should be confirmed through molecular techniques in patients who present with "spotless" Rocky Mountain spotted fever or have serum antibodies to R. rickettsii with group-specific assays.

Shapiro MR; Fritz CL; Tait K; Paddock CD; Nicholson WL; Abramowicz KF; Karpathy SE; Dasch GA; Sumner JW; Adem PV; Scott JJ; Padgett KA; Zaki SR; Eremeeva ME

2010-02-01

243

Experimental infection of cotton rats and bobwhite quail with Rickettsia parkeri.  

UK PubMed Central (United Kingdom)

BACKGROUND: Amblyomma maculatum is the primary vector for Rickettsia parkeri, a spotted fever group rickettsia (SFGR) and human pathogen. Cotton rats and quail are known hosts for larval and nymphal A. maculatum; however, the role of these hosts in the ecology of R. parkeri is unknown. METHODS: Cotton rats and quail were inoculated with low or high doses of R. parkeri (strain Portsmouth) grown in Vero cells to evaluate infection by R. parkeri in these two hosts species. Animals were euthanized 2, 4, 7, 10, and 14 days post-injection (dpi) and blood, skin, and spleen samples were collected to analyze by Vero cell culture and polymerase chain reaction (PCR). In a second trial, cotton rats and quail were inoculated with R. parkeri and nymphal A. maculatum ticks were allowed to feed on animals. Animals were euthanized on 14, 20, 28, 31, and 38 dpi and blood and tissues were collected for serology and PCR assays. Fed ticks were tested for R. parkeri by PCR and Vero cell culture. RESULTS: Rickettsia parkeri was isolated in cell culture and detected by PCR in skin, blood, and spleen tissues of cotton rats in the initial trial 2, 4, and 7 dpi, but not in quail tissues. In the second trial, no ticks tested positive for R. parkeri by PCR or cell culture. CONCLUSIONS: These studies demonstrate that viable R. parkeri rickettsiae can persist in the tissues of cotton rats for at least 7 days following subcutaneous inoculation of these bacteria; however, quail are apparently resistant to infection. Rickettsia parkeri was not detected in nymphal ticks that fed on R. parkeri-inoculated cotton rats or quail, suggesting an alternate route of transmission to naïve ticks.

Moraru GM; Goddard J; Paddock CD; Varela-Stokes A

2013-01-01

244

Dissemination of bloodmeal acquired Rickettsia felis in cat fleas, Ctenocephalides felis.  

Science.gov (United States)

BACKGROUND: Cat fleas, Ctenocephalides felis, are known biological vectors for Rickettsia felis. Rickettsial transmission can be vertical via transovarial transmission within a flea population, as well as horizontal between fleas through a bloodmeal. The previously undescribed infection kinetics of bloodmeal-acquired R. felis in cat fleas provides insight into the R. felis-flea interaction. FINDINGS: In the present study, dissemination of R. felis in previously uninfected cat fleas fed an R. felis-infected bloodmeal was investigated. At weekly intervals for 28 days, rickettsial propagation, accumulation, and dissemination in gut epithelial cells, specifically in the hindgut and the specialized cells in the neck region of midgut, were observed on paraffin sections of infected cat fleas by immunofluorescence assay (IFA) and confirmed by PCR detection of R. felis 17-kDa antigen gene. IFA results demonstrate ingested rickettsiae in vacuoles during early infection of the gut; lysosomal activity, indicated by lysosome marker staining of freshly-dissected gut, suggests the presence of phagolysosome-associated vacuoles. Subsequent to infection in the gut, rickettsiae spread to the hemocoel and other tissues including reproductive organs. Densely-packed rickettsiae forming mycetome-like structures were observed in the abdomen of infected male cat fleas during late infection. Ultrastructural analysis by transmission electron microscopy (TEM) confirmed the presence and infection characteristics of Rickettsia including rickettsial destruction in the phagolysosome, rickettsial division, and accumulation in the flea gut. CONCLUSIONS: This study intimately profiles R. felis dissemination in cat fleas and further illuminates the mechanisms of rickettsial transmission in nature. PMID:23705666

Thepparit, Chutima; Hirunkanokpun, Supanee; Popov, Vsevolod L; Foil, Lane D; Macaluso, Kevin R

2013-05-24

245

Laboratory Tests of Arthropod Repellents Against Leptotrombidium deliense - Noninfected and Infected with Rickettsia tsutsugamushi - and Noninfected L. fletcheri (Acari: Trombiculidae).  

Science.gov (United States)

Laboratory tests were conducted to compare the response of noninfected Leptotrumbidium deliense Sambon and Leptotrnmbidiumfletcheri (Womersley Heaslip) and L. deliense naturally infected with Rickettsia tsutsugamushi, the etiologic agent of scrub typhus, ...

S. P. Frances N. Khlaimanee

1994-01-01

246

Genome Sequencing of Four Strains of Rickettsia prowazekii, the Causative Agent of Epidemic Typhus, Including One Flying Squirrel Isolate  

Science.gov (United States)

Rickettsia prowazekii is a notable intracellular pathogen, the agent of epidemic typhus, and a potential biothreat agent. We present here whole-genome sequence data for four strains of R. prowazekii, including one from a flying squirrel.

Ge, Hong; Butani, Amy; Osborne, Brian; Verratti, Kathleen; Mokashi, Vishwesh; Nagarajan, Niranjan; Pop, Mihai; Read, Timothy D.; Richards, Allen L.

2013-01-01

247

Methods for purification of Rickettsia prowazekii separated from the host tissue: a step-by-step comparison.  

Science.gov (United States)

Two methods for purification of Rickettsia prowazekii strains E, E Vir, and Breinl grown in chick embryo yolk sacs are described. These methods combine either differential centrifugation or sucrose mix, centrifugation through sucrose cushion, 10 mmol/l MgCl2 treatment, filtration through a glass filter AP-20 and 2 cycles of verografin discontinuous density gradient centrifugation. The purification procedure including sucrose mix allowed to recover about 38-42% biologically active rickettsiae, a yield which was by 10% higher than that obtained by the method beginning at differential centrifugation. The rickettsiae free of host cell components preserved their infectious activity. The obtained biomass was suitable for immunological and biological characterization of Rickettsia prowazekii and for isolation of its total DNA. PMID:2574944

Aniskovich, L P; Eremeeva, M E; Balaeva, N M; Ignatovich, V F; Artemiev, M I; Emelyanov, V V; Smirnova, N S

1989-08-01

248

Methods for purification of Rickettsia prowazekii separated from the host tissue: a step-by-step comparison.  

UK PubMed Central (United Kingdom)

Two methods for purification of Rickettsia prowazekii strains E, E Vir, and Breinl grown in chick embryo yolk sacs are described. These methods combine either differential centrifugation or sucrose mix, centrifugation through sucrose cushion, 10 mmol/l MgCl2 treatment, filtration through a glass filter AP-20 and 2 cycles of verografin discontinuous density gradient centrifugation. The purification procedure including sucrose mix allowed to recover about 38-42% biologically active rickettsiae, a yield which was by 10% higher than that obtained by the method beginning at differential centrifugation. The rickettsiae free of host cell components preserved their infectious activity. The obtained biomass was suitable for immunological and biological characterization of Rickettsia prowazekii and for isolation of its total DNA.

Aniskovich LP; Eremeeva ME; Balaeva NM; Ignatovich VF; Artemiev MI; Emelyanov VV; Smirnova NS

1989-08-01

249

Genome Sequencing of Four Strains of Rickettsia prowazekii, the Causative Agent of Epidemic Typhus, Including One Flying Squirrel Isolate.  

Science.gov (United States)

Rickettsia prowazekii is a notable intracellular pathogen, the agent of epidemic typhus, and a potential biothreat agent. We present here whole-genome sequence data for four strains of R. prowazekii, including one from a flying squirrel. PMID:23814035

Bishop-Lilly, Kimberly A; Ge, Hong; Butani, Amy; Osborne, Brian; Verratti, Kathleen; Mokashi, Vishwesh; Nagarajan, Niranjan; Pop, Mihai; Read, Timothy D; Richards, Allen L

2013-06-27

250

Characterization of a new spotted fever group rickettsia detected in Ixodes ricinus (Acari: Ixodidae) collected in Slovakia.  

Science.gov (United States)

Two previously undescribed rickettsiae were detected in Ixodes ricinus Ricketts by polymerase chain reaction. Ixodes ricinus Slovakia (IRS) 3 and IRS4 were identified in ticks collected in northeastern and southwestern Slovakia, respectively. Sequences of the 16S rRNA citrate synthase (gltA) and outer membrane protein rOmpA (ompA) encoding genes of both strains were nearly identical but were distinct from those of all other known rickettsiae. Phylogenetic relationships inferred from the comparison of these sequences with those of other members of the genus Rickettsia indicate that IRS3 and IRS4 constitute a new rickettsial genotype and form a separate cluster among the spotted fever group rickettsiae. PMID:11004782

Sekeyová, Z; Fournier, P E; Rehácek, J; Raoult, D

2000-09-01

251

Characterization of a new spotted fever group rickettsia detected in Ixodes ricinus (Acari: Ixodidae) collected in Slovakia.  

UK PubMed Central (United Kingdom)

Two previously undescribed rickettsiae were detected in Ixodes ricinus Ricketts by polymerase chain reaction. Ixodes ricinus Slovakia (IRS) 3 and IRS4 were identified in ticks collected in northeastern and southwestern Slovakia, respectively. Sequences of the 16S rRNA citrate synthase (gltA) and outer membrane protein rOmpA (ompA) encoding genes of both strains were nearly identical but were distinct from those of all other known rickettsiae. Phylogenetic relationships inferred from the comparison of these sequences with those of other members of the genus Rickettsia indicate that IRS3 and IRS4 constitute a new rickettsial genotype and form a separate cluster among the spotted fever group rickettsiae.

Sekeyová Z; Fournier PE; Rehácek J; Raoult D

2000-09-01

252

Caracterização de Rickettsia spp. circulante em foco silencioso de febre maculosa brasileira no Município de Caratinga, Minas Gerais, Brasil  

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Full Text Available O objetivo deste trabalho foi caracterizar Rickettsia spp. circulante em artrópodes vetores no Município de Caratinga, Minas Gerais, Brasil, por meio da PCR, e investigar a presença de anticorpos para riquétsias do grupo da febre maculosa em cães e eqüinos. 2.610 ectoparasitos foram coletados e identificados taxonomicamente. Amostras de DNA obtidas desses vetores foram submetidas à PCR e seqüenciamento. Em pulgas do gênero Ctenocephalides e em carrapatos Amblyomma cajennense foram identificadas seqüências com 100% de homologia com R. felis. Em carrapatos Rhipicephalus sanguineus uma seqüência apresentou 99% de homologia com R. felis e uma seqüência obtida de A. cajennense apresentou 97% de homologia com R. honei e R. rickettsii. Soros de cães (73) e de eqüinos (18) foram submetidos à imunofluorescência indireta (RIFI) usando-se antígeno de R. rickettsii. Apenas três dos soros de eqüinos (17%) mostraram-se positivos. A detecção molecular de riquetsias potencialmente patogênicas ao homem em vetores e a presença de sororeatividade para riquetsias do grupo da febre maculosa em eqüinos, demonstram o risco de transmissão de riquetsioses nessa área e a necessidade de se manter um sistema contínuo de vigilância epidemiológica.

Cardoso Luciane Daniele; Freitas Renata Nascimento; Mafra Cláudio Lísias; Neves Cristiane Vilas Boas; Figueira Fátima Cristina Bacellar; Labruna Marcelo Bahia; Gennari Solange M.; Walker David Hughes; Galvão Márcio Antônio Moreira

2006-01-01

253

The first report of Rickettsia spp. in Amblyomma nodosum in the State of Mato Grosso do Sul, Brazil.  

UK PubMed Central (United Kingdom)

Ticks are vectors of various pathogens, including Rickettsia spp., which are responsible for causing an emerging disease of global significance. In the present study, an epidemiological survey was performed to identify Rickettsia spp. of the spotted fever group (SFG) in ticks and wild hosts in a native forest adjacent to livestock farming activity. The ticks and blood were evaluated by a hemolymph test and by PCR using the primers CS78 and CS323, which target a partial sequence of the enzyme citrate synthase (gltA) gene. Positive samples by PCR were further tested with the primers Rr190.70p and Rr190.602n, which target a 532-bp fragment of the rickettsial 190-kDa outer membrane protein gene (ompA). In addition, an indirect immunofluorescence assay (IFA) was performed to detect antibodies against Rickettsia spp. in horses that inhabited the same area. From the 43 animals that were captured, 192 ticks were collected; the ticks belonged to the species Amblyomma cajennense, A. ovale, and A. nodosum. All blood samples and hemolymph tests were negative. Four samples of A. nodosum that were collected from Tamandua tetradactyla were positive for Rickettsia spp. by PCR, and 8 samples of horse serum displayed titers greater than or equal to 1:64 by IFA. The phylogenetic analysis based on the DNA sequence of the ompACG gene demonstrated that Rickettsia spp. CG (the canadensis group) segregate in the same cluster as Rickettsia parkeri strain COOPERI, with a bootstrap value of 78%. These results indicate that Rickettsia spp. CG circulate among the tick population in the study area, which has a constant presence of livestock and humans. This may be the same species of Rickettsia that was recorded in A. nodosum throughout the Atlantic forest.

Almeida RF; Garcia MV; Cunha RC; Matias J; Labruna MB; Andreotti R

2013-02-01

254

Short report: New spotted fever group Rickettsia in a Rhipicephalus turanicus tick removed from a child in eastern Sicily, Italy.  

UK PubMed Central (United Kingdom)

A new genotype of spotted fever group Rickettsia (SFGR) was identified in Rhipicephalus turanicus from eastern Sicily. On the basis of current molecular criteria, the genetic characteristics obtained from multiple locus sequence typing satisfy the requirements for Candidatus status of this SFGR. Further detection and identification of this SFGR during entomological and clinical surveys will be required to establish the prevalence of this Rickettsia and its potential pathogenicity for humans.

Eremeeva ME; Stromdahl EY

2011-01-01

255

Closing the gaps between genotype and phenotype in Rickettsia rickettsii.  

UK PubMed Central (United Kingdom)

Rocky Mountain spotted fever (RMSF) caused by Rickettsia rickettsii is a severe rickettsiosis that occurs in nearly every state of the continental USA. RMSF is endemic in Central and Southern America, with recent well-documented cases in Mexico, Costa Rica, Panama, Colombia, Brazil, and Argentina. RMSF is the most malignant among known rickettsioses causing severe multiorgan dysfunction and high case fatality rates, which can reach 73% in untreated cases. Variations in pathogenic biotypes of R. rickettsii isolates have been described, and potential correlations of these differences to various clinical manifestations of RMSF have been suggested. We have recently reported on a method of genetic comparison employing sequence differences in intergenic regions (IGR typing) in isolates of R. rickettsii of human, tick, and animal origin. The grouping obtained correlated well with 2 other genotyping systems we have developed, which target the presence and distribution of variable numbers of tandem repeats (TR) and insertion/deletion (INDEL) events. Twenty-five total genotypes of R. rickettsii in 4 primary groups could be distinguished: isolates from Montana, isolates associated with Rhipicephalus sanguineus ticks and human infections in Arizona, other isolates from the USA where Dermacentor variabilis is thought to be the primary vector, and the isolates primarily associated with Amblyomma ticks from Central and South America. In addition, isolate Hlp#2, which is often considered to be a nonpathogenic isolate of R. rickettsii and closely related serotype 364D, exhibited the most diversity from the other isolates compared, and they differ significantly from each other. Because complex interactions underlie the pathogenesis of R. rickettsii in vivo, it is difficult to define the causality of individual events that occur in infected vertebrate hosts and humans. Many microbial factors are likely to contribute to the varied ability of R. rickettsii to cause cellular injury; some of them may also contribute importantly to its virulence for vertebrate hosts and may be linked to the variable genetic markers we have identified. Since circulation of R. rickettsii in nature includes vertical transstadial and transovarial transmission within tick vectors and horizontal passages through vertebrate hosts, it is plausible that isolates of different virulence arose when they became isolated during adaptation to novel vertebrate and tick hosts. Characterization of the physiologically important changes in rickettsial gene expression that occur immediately after tick-to-human or tick-to-animal transitions may require development of new experimental systems.

Eremeeva ME; Dasch GA

2009-05-01

256

A Rickettsia WASP-like protein activates the Arp2/3 complex and mediates actin-based motility.  

Science.gov (United States)

Spotted fever group Rickettsia are obligate intracellular pathogens that exploit the host cell actin cytoskeleton to promote motility and cell-to-cell spread. Although other pathogens such as Listeria monocytogenes use an Arp2/3 complex-dependent nucleation mechanism to generate comet tails consisting of Y-branched filament arrays, Rickettsia polymerize tails consisting of unbranched filaments by a previously unknown mechanism. We identified genes in several Rickettsia species encoding proteins (termed RickA) with similarity to the WASP family of Arp2/3-complex activators. Rickettsia rickettsii RickA activated both the nucleation and Y-branching activities of the Arp2/3 complex like other WASP-family proteins, and was sufficient to direct the motility of microscopic beads in cell extracts. Actin tails generated by RickA-coated beads consisted of Y-branched filament networks. These data suggest that Rickettsia use an Arp2/3 complex-dependent actin-nucleation mechanism similar to that of other pathogens. We propose that additional Rickettsia or host factors reorganize the Y-branched networks into parallel arrays in a manner similar to a recently proposed model of filopodia formation. PMID:15236643

Jeng, Robert L; Goley, Erin D; D'Alessio, Joseph A; Chaga, Oleg Y; Svitkina, Tatyana M; Borisy, Gary G; Heinzen, Robert A; Welch, Matthew D

2004-08-01

257

A Rickettsia WASP-like protein activates the Arp2/3 complex and mediates actin-based motility.  

UK PubMed Central (United Kingdom)

Spotted fever group Rickettsia are obligate intracellular pathogens that exploit the host cell actin cytoskeleton to promote motility and cell-to-cell spread. Although other pathogens such as Listeria monocytogenes use an Arp2/3 complex-dependent nucleation mechanism to generate comet tails consisting of Y-branched filament arrays, Rickettsia polymerize tails consisting of unbranched filaments by a previously unknown mechanism. We identified genes in several Rickettsia species encoding proteins (termed RickA) with similarity to the WASP family of Arp2/3-complex activators. Rickettsia rickettsii RickA activated both the nucleation and Y-branching activities of the Arp2/3 complex like other WASP-family proteins, and was sufficient to direct the motility of microscopic beads in cell extracts. Actin tails generated by RickA-coated beads consisted of Y-branched filament networks. These data suggest that Rickettsia use an Arp2/3 complex-dependent actin-nucleation mechanism similar to that of other pathogens. We propose that additional Rickettsia or host factors reorganize the Y-branched networks into parallel arrays in a manner similar to a recently proposed model of filopodia formation.

Jeng RL; Goley ED; D'Alessio JA; Chaga OY; Svitkina TM; Borisy GG; Heinzen RA; Welch MD

2004-08-01

258

[Surveillance of Rickettsia sp. infection in capybaras (Hydrochoerus hydrochaeris) a potential model of epidemiological alert in endemic areas].  

UK PubMed Central (United Kingdom)

INTRODUCTION: Capybaras (Hydrochoerus hydrochaeris) are considered amplifying hosts of Rickettsia sp. These rodents are usually parasitized by the tick vector, Amblyomma cajennense, the main vector of rickettsioses in humans and animals in South America. Capybaras can be used as sentinels in detection of circulation of rickettsiae. OBJECTIVE: Antibodies to rickettsiae of spotted fever group were detected in capybaras in a rural area of Cordoba Province, northern Colombia. MATERIALS AND METHODS: Sera were analyzed from 36 capybaras in a rural area of Monteria (village of San Jeronimo) in Córdoba. For the detection of IgG antibodies, indirect immunofluorescence was performed. The antigens were derived from R. rickettsia strain Taiaçu isolated in Brazil. Capybara sera were diluted 1:64 for IFA analysis. Ticks were collected from each capybara (also known as chigüiro) and identified to species. RESULTS: The seroprevalence of spotted fever group Rickettsia was 22% (8 capybaras). Four sera had a titer of 1:64, 3 had a titer of 1:128 and one serum had a titer of 1:512. All ticks removed from the capybaras (n=933) were taxonomically identified as Amblyomma cajennense. CONCLUSION: Colombia has areas endemic for rickettsioses, as indicated by confirmed annual outbreaks. The current study reports the first evidence of natural rickettsial infection of the spotted fever group in capybaras from Colombia. The findings suggest that capybaras can be used as sentinels for the circulation of rickettsiae and can identify endemic areas for the transmission of rickettsial diseases.

Miranda J; Contreras V; Negrete Y; Labruna MB; Máttar S

2011-06-01

259

The first molecular detection of Rickettsia aeschlimannii in the ticks of camels from southern Algeria.  

UK PubMed Central (United Kingdom)

We collected ticks from camels in 4 regions of southern Algeria (El Oued, Bechar, Ghardia, and Adrar) from February to October in 2008 and in April of 2011. A total of 307 ticks representing multiple species (including Hyalomma dromedarii, H. marginatum rufipes, H. impeltatum, and H. impressum), was tested for the presence of spotted fever group rickettsia DNA using gltA real-time quantitative PCR (qPCR). The presence of Rickettsia aeschlimannii was confirmed with a new qPCR using species-specific primers and Taqman probes based on the sca2 genes. The R. aeschlimannii sequence was further confirmed by detecting the gltA and outer membrane protein (ompA) genes in H. m. rufipes, H. impeltatum, and H. dromedarii ticks. These findings represent the first report of the detection of R. aeschlimannii in ticks collected from camels from southern Algeria.

Djerbouh A; Kernif T; Beneldjouzi A; Socolovschi C; Kechemir N; Parola P; Raoult D; Bitam I

2012-12-01

260

Crystal structure of the N-terminal domains of the surface cell antigen 4 of Rickettsia.  

Science.gov (United States)

The obligate intracellular, gram-negative bacterium Rickettsia is the causative agent of spotted fevers and typhus in humans. Surface cell antigen (sca) proteins surround these bacteria. We recently reported the co-localization of one of these proteins, sca4, with vinculin in cells at sites of focal adhesions and demonstrated that two vinculin binding sites directed the sca4/vinculin interaction. Here we report the 2.2 Å crystal structure of the conserved N-terminal 38 kDa domain of sca4 from Rickettsia rickettsii. The structure reveals two subdomains. The first is an all-helical domain that is folded in a fashion similar to the dimeric assembly chaperone for rubisco, namely RbcX. The following and highly conserved ?-strand domain lacks significant structural similarity with other known structures and to the best of our knowledge represents a new protein fold. PMID:23904352

Lee, Jun Hyuck; Vonrhein, Clemens; Bricogne, Gerard; Izard, Tina

2013-08-28

 
 
 
 
261

Evidence of spotted fever group rickettsiae in state of Rio de Janeiro, Brazil  

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Full Text Available Ticks were obtained from dogs from February to September of 1999 at weekly intervals, in the County of Piraí, State of Rio de Janeiro. Four hundred seventy four ixodids were taxonomically identified, 103 Amblyomma cajennense, seven Amblyomma ovale, 209 Rhipicephalus sanguineus, and 155 Amblyomma sp. An hemolymph test associated with Giemsa's stain revealed two specimens in 163 ticks tested (R. sanguineus and Amblyomma sp), containing rickettsia-like organisms. Direct immunofluorescence verified the presence of spotted fever group rickettsia in one specimen of R. sanguineus. Considering the limited information on rickettsiosis in Brazil, principally in relation to the vectors involved in perpetuating it in foci, these preliminary results give us an idea on the importance of infection in ticks, allowing to expand our knowledge on this zoonosis.

ROZENTAL Tatiana; BUSTAMANTE Maria Cristina; AMORIM Marinete; SERRA-FREIRE Nicolau Maués; LEMOS Elba Regina Sampaio de

2002-01-01

262

Crystal structure of the N-terminal domains of the surface cell antigen 4 of Rickettsia.  

UK PubMed Central (United Kingdom)

The obligate intracellular, gram-negative bacterium Rickettsia is the causative agent of spotted fevers and typhus in humans. Surface cell antigen (sca) proteins surround these bacteria. We recently reported the colocalization of one of these proteins, sca4, with vinculin in cells at sites of focal adhesions and demonstrated that two vinculin binding sites directed the sca4/vinculin interaction. Here we report the 2.2 Å crystal structure of the conserved N-terminal 38 kDa domain of sca4 from Rickettsia rickettsii. The structure reveals two subdomains. The first is an all-helical domain that is folded in a fashion similar to the dimeric assembly chaperone for rubisco, namely RbcX. The following and highly conserved ?-strand domain lacks significant structural similarity with other known structures and to the best of our knowledge represents a new protein fold.

Lee JH; Vonrhein C; Bricogne G; Izard T

2013-07-01

263

Description of "yaaf", the vesicular fever caused by acute Rickettsia felis infection in Senegal.  

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Rickettsiosis caused by Rickettsia felis is an emerging infection in Africa and may account for 3-4% of ambulatory febrile fevers. We report herein a case of R. felis infection, for which we propose the name "yaaf", meaning vesicle, in an 8-month-old girl who was diagnosed in the field by real-time PCR analysis of a skin lesion; these PCR analysis was performed at a local experimental point-of-care laboratory. The clinical presentation was polymorphous skin lesions, including papules, vesicles, erosions and ulcers. The patient did not produce antibodies against Rickettsia. We suggest that this disease may be a primary infection caused by R. felis. PMID:23068450

Mediannikov, Oleg; Fenollar, Florence; Bassene, Hubert; Tall, Adama; Sokhna, Cheikh; Trape, Jean-François; Raoult, Didier

2012-10-13

264

Anaplasma phagocytophilum and Rickettsia spp. infections in hard ticks (Ixodes ricinus) in the city of Hanover (Germany): Revisited.  

UK PubMed Central (United Kingdom)

The present study aimed to determine the prevalence of Rickettsiales (A. phagocytophilum and Rickettsia spp.) in 2100 I. ricinus ticks collected at 10 different sampling sites every month during the tick season 2010 in the city of Hanover, northern Germany. At the same time, the results served as a fifth-year-follow-up study to monitor whether changes or stagnation of tick infection rates - possibly due to climate change - were obvious or not. To detect infections with A. phagocytophilum and/or Rickettsia spp., tick samples were analysed by quantitative real-time PCR. Differentiation of Rickettsia species was accomplished using real-time pyrosequencing technology. Overall, 4.5% (94/2100) of the collected ticks were tested positive for A. phagocytophilum and 26.2% (551/2100) were positive for Rickettsia spp. infections. Species differentiation of Rickettsia-positive ticks via real-time pyrosequencing was possible in 48.6% (268/551) of samples, which were all identified as R. helvetica. Coinfections with both pathogens were found in 1.0% (20/2100) of ticks. Statistically significant seasonal fluctuations between sampling months as well as local differences between sampling sites were detected for Rickettsia spp. infection rates. For A. phagocytophilum infections, only significant seasonal variations were found. When comparing infection rates of Hanoverian ticks in 2010 to those in 2005, infection rates of A. phagocytophilum-infected nymphs increased statistically significant (P=0.008, power: 0.762) from 2.3% in 2005 (Schicht et al., 2011) to 4.5% in 2010. Rickettsia spp. infections in female ticks decreased significantly (P=0.049, power: 0.491) from 41.8% in 2005 (Schicht et al., 2012) to 32.4% in 2010. Comparison of the remaining tick stages showed no statistically significant differences.

Tappe J; Strube C

2013-07-01

265

Detection of Leishmania infantum, Babesia canis, and rickettsiae in ticks removed from dogs living in Italy.  

Science.gov (United States)

The aims of this study were to determine natural infections by Anaplasma phagocytophilum/Anaplasma platys, Bartonella henselae, Ehrlichia canis, Leishmania infantum, Rickettsia spp., Babesia spp., and Hepatozoon spp. by molecular methods in ticks (n=91) removed from dogs with clinical signs and laboratory abnormalities compatible with tick-borne diseases (n=22) living in Italy and to assess the distribution and species of ticks encountered. Ticks from dogs living in southern Italy were all identified as Rhipicephalus sanguineus (n=25), ticks from central Italy included Rh. sanguineus (n=8) and Ixodes ricinus (n=9), ticks from northern Italy included Rh. sanguineus (n=45), Dermacentor marginatus (n=3), and one I. ricinus. Leishmania infantum, Rickettsia spp., and Babesia canis were the only pathogens detected in 7 (8%), 4 (4%), and 2 (2%) out of 91 ticks, respectively. L. infantum was detected in I. ricinus from central Italy and in Rh. sanguineus from northern and central Italy. Rickettsia conorii and Ri. massiliae were detected in Rh. sanguineus ticks from central and southern Italy (Sicily), respectively. Bab. canis was detected in D. marginatus ticks from northern Italy. PMID:23182545

Trotta, Michele; Nicetto, Martina; Fogliazza, Alessandro; Montarsi, Fabrizio; Caldin, Marco; Furlanello, Tommaso; Solano-Gallego, Laia

2012-11-20

266

Detection of Leishmania infantum, Babesia canis, and rickettsiae in ticks removed from dogs living in Italy.  

UK PubMed Central (United Kingdom)

The aims of this study were to determine natural infections by Anaplasma phagocytophilum/Anaplasma platys, Bartonella henselae, Ehrlichia canis, Leishmania infantum, Rickettsia spp., Babesia spp., and Hepatozoon spp. by molecular methods in ticks (n=91) removed from dogs with clinical signs and laboratory abnormalities compatible with tick-borne diseases (n=22) living in Italy and to assess the distribution and species of ticks encountered. Ticks from dogs living in southern Italy were all identified as Rhipicephalus sanguineus (n=25), ticks from central Italy included Rh. sanguineus (n=8) and Ixodes ricinus (n=9), ticks from northern Italy included Rh. sanguineus (n=45), Dermacentor marginatus (n=3), and one I. ricinus. Leishmania infantum, Rickettsia spp., and Babesia canis were the only pathogens detected in 7 (8%), 4 (4%), and 2 (2%) out of 91 ticks, respectively. L. infantum was detected in I. ricinus from central Italy and in Rh. sanguineus from northern and central Italy. Rickettsia conorii and Ri. massiliae were detected in Rh. sanguineus ticks from central and southern Italy (Sicily), respectively. Bab. canis was detected in D. marginatus ticks from northern Italy.

Trotta M; Nicetto M; Fogliazza A; Montarsi F; Caldin M; Furlanello T; Solano-Gallego L

2012-12-01

267

Rickettsia species infecting Amblyomma ticks from an area endemic for Brazilian spotted fever in Brazil.  

UK PubMed Central (United Kingdom)

This study reports rickettsial infection in Amblyomma cajennense and Amblyomma dubitatum ticks collected in an area of the state of Minas Gerais, Brazil, where Brazilian spotted fever is considered endemic. For this purpose, 400 adults of A. cajenennse and 200 adults of A. dubitatum, plus 2,000 larvae and 2,000 nymphs of Amblyomma spp. were collected from horses and from the vegetation. The ticks were tested for rickettsial infection through polymerase chain reaction (PCR) protocols targeting portions of three rickettsial genes (gltA, ompA, and ompB). Only two free?living A. cajennense adult ticks, and four pools of free-living Amblyomma spp. nymphs were shown to contain rickettsial DNA. PCR products from the two A. cajennense adult ticks were shown to be identical to corresponding sequences of the Rickettsia rickettsii strain Sheila Smith. DNA sequences of gltA-PCR products of the four nymph pools of Amblyomma spp. revealed a new genotype, which was shown to be closest (99.4%) to the corresponding sequence of Rickettsia tamurae. Our findings of two R. rickettsii-infected A. cajennense ticks corroborate the endemic status of the study area, where human cases of BSF were reported recently. In addition, we report for the first time a new Rickettsia genotype in Brazil.

Guedes E; Leite RC; Pacheco RC; Silveira I; Labruna MB

2011-10-01

268

Spotted fever group Rickettsia infecting ticks (Acari: Ixodidae) in the state of Santa Catarina, Brazil.  

UK PubMed Central (United Kingdom)

During 2006-2008, a total of 260 adult ticks were collected from domestic and wild animals in different regions of the state of Santa Catarina (SC), Brazil, including areas where human cases of Brazilian spotted fever have been reported. Collected ticks belonging to nine species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Amblyomma longirostre, Amblyomma ovale, Amblyomma tigrinum, Dermacentor nitens, Rhipicephalus microplus and Rhipicephalus sanguineus) were tested by polymerase chain reaction (PCR) for rickettsial infection. Overall, eight (3.1%) ticks were found to be infected with Rickettsia species. After sequencing the PCR products, we determined that the sequences generated from three A. aureolatum, one A. ovale and one R. sanguineus from the municipality of Blumenau, one A. ovale from the municipality of Águas Mornas and one A. ovale from the municipality of Urussanga were identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia parkeri strain Atlantic rainforest. The sequence generated from one A. longirostre from Blumenau was 100% identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia amblyommii strain AL. Because R. parkeri strain Atlantic rainforest was recently shown to have caused two cases of human spotted fever in other states of Brazil, the role of this rickettsial agent as a possible etiological agent of spotted fever in SC is discussed.

Medeiros AP; Souza AP; Moura AB; Lavina MS; Bellato V; Sartor AA; Nieri-Bastos FA; Richtzenhain LJ; Labruna MB

2011-12-01

269

ISOLATION OF Rickettsia bellii FROM Amblyomma ovale AND Amblyomma incisum TICKS FROM SOUTHERN BRAZIL  

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Full Text Available Objective. To isolate and characterize rickettsiae from the ticks Amblyomma ovale and Amblyomma incisum collected in the state of São Paulo. Materials and methods. Adult, free-living A. ovale and A. incisum were collected in an Atlantic rainforest area in the state of São Paulo, Brazil. Each tick was tested using the hemolymph assay; samples from positive ticks were placed in shell vials in order to isolate rickettsiae and subsequently grown in Vero cells. Amplification of three rickettsial genes (gltA, htrA and ompA) was attempted using polymerase chain reaction (PCR) for each isolate obtained. Amplicons were subsequently sequenced. Results. A total of 388 A. incisum and 50 A. ovale were collected. Only one A. incisum and one A. ovale were hemolymph-test positive. Rickettsiae were successfully isolated from these ticks; however establishment in Vero cell culture was successful only for the isolate from A. ovale. Bacterial contamination in the first cell passage of the A. incisum isolate precluded successful isolation of the organism. PCR products were obtained with the gltA and htrA primers for the two isolates, but no product was obtained with the ompA primers. By BLAST analysis, partial gltA and htrA sequences of isolates from A. ovale and A. incisum were similar to the corresponding sequences of R. bellii. Conclusions. This is the first report of R. bellii infecting A. incisum and the first successful isolation from A. ovale.

Richard Pacheco; Simone Rosa; Leonardo Richtzenhain; Matias P. J. Szabó; Marcelo B. Labruna

2008-01-01

270

Detection of Rickettsia rickettsii and Bartonella henselae in Rhipicephalus sanguineus ticks from California.  

UK PubMed Central (United Kingdom)

Sixty-two questing adult Rhipicephalus sanguineus (Latreille) ticks were collected by direct removal from blades of turfgrass and adjacent concrete walkways at a suburban home in Riverside County, CA, and tested for the presence of Rickettsia, Bartonella, and Ehrlichia DNA. Polymerase chain reaction (PCR) was used to amplify fragments of the 17-kDa antigen gene and the rOmpA gene of the spotted fever group rickettsiae. One male tick contained R. rickettsii DNA; its genotype differed from R. rickettsii isolates found in Montana and Arizona that cause Rocky Mountain spotted fever and from Hlp#2 and 364D serotypes. One male tick and one female tick contained B. henselae DNA. No Ehrlichia platys or Ehrlichia canis DNAs were detected using nested PCR for their 16S rRNA genes. These findings extend the area where Rickettsia rickettsii may be vectored by Rh. sanguineus. Rh. sanguineus also may be infected with Bartonella henselae, a human pathogen that is typically associated with fleas and causes cat scratch disease.

Wikswo ME; Hu R; Metzger ME; Eremeeva ME

2007-01-01

271

Rickettsia africae in Amblyomma variegatum and domestic ruminants on eight Caribbean islands.  

UK PubMed Central (United Kingdom)

We used PCRs with omp A primers to determine if spotted fever group rickettsiae occurred in Amblyomma variegatum from 6 Caribbean islands. Positive amplicons were obtained from ticks from the U.S. Virgin Islands (9/18; 50%), Dominica (39/171; 30%), Montserrat (2/5; 40%), Nevis (17/34; 50%), St. Kitts (46/227; 20%), and St. Lucia (1/14; 7%). Sequences for a convenience sample of reaction products obtained from A. variegatum on St. Kitts (7), American Virgin Islands (4), Montserrat (2), and St. Lucia (1) were 100% homologous with that of Rickettsia africae , the agent of African tick-bite fever. To determine if transmission of R. africae occurred, we used Rickettsia rickettsii antigen in IFA tests and found positive titers (? 1/80) with sera from cattle, goats, and sheep from Dominica (24/95 [25%], 2/136 [2%], 0/58 [0%]), Nevis (12/45 [27%], 5/157 [3%], 0/90 [0%]), St. Kitts (2/43 [5%], 1/25 [4%), 1/35 [3%]), and St. Lucia (6/184 [3%] cattle), respectively. No seropositive animals were found in Grenada (0/4, 0/98/, 0/86), Montserrat (0/12, 0/26, 0/52), or Puerto Rico (0/80 cattle). Our study indicates that R. africae and African tick-bite fever are widespread in the Caribbean.

Kelly P; Lucas H; Beati L; Yowell C; Mahan S; Dame J

2010-12-01

272

Detection of anti: Rickettsia spp. antibodies in domestic chickens of extensive breeding in an endemic area for spotted fever in the state of Rio Grande do Sul, Brazil/ Detecção de anticorpos anti: Rickettsia spp. em galinhas domésticas de criação extensiva em uma área endêmica para febre maculosa no estado do Rio Grande do Sul, Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Este estudo teve como objetivo pesquisar anticorpos anti-Rickettsia spp. em soros de galinhas domésticas (Gallus gallus domesticus) de criação extensiva, provenientes de área considerada endêmica para febre maculosa no estado do Rio Grande do Sul. Foram coletadas 300 amostras de sangue e os soros obtidos foram testados para anticorpos anti-Rickettsia spp. pela Reação de Imunofluorescência Indireta (RIFI). A ocorrência de anticorpos anti-Rickettsia spp. observada (more) foi de 1,33% (4/300), com títulos variando de 64 a 256 para Rickettsia rickettsii, Rickettsia parkeri e/ou Rickettsia bellii. Os resultados sugerem que essas galinhas domésticas não participam como reservatório e/ou hospedeiro amplificador na epidemiologia da febre maculosa na área endêmica. O presente estudo consiste na primeira pesquisa sorológica em Gallus gallus domesticus para rickettsia do grupo da febre maculosa no Brasil. Abstract in english The goal of this study was to investigate anti-Rickettsia spp. antibodies in sera of domestic chickens (Gallus gallus domesticus) of extensive breeding in Cerro Largo county, considered an endemic area for spotted fever in the State of Rio Grande do Sul, Brazil. Three hundred blood samples were collected and anti-Rickettsia spp. antibodies were evaluated by indirect immunofluorescence assay (IFA) in the sera obtained. The occurrence of anti-Rickettsia spp. antibodies dete (more) cted in this study was 1.33% (4/300), with endpoint titers ranging from 64 to 256 for Rickettsia rickettsiii, R. parkeri and/or R. bellii. The results suggest these domestic chickens do not participate as a reservoir and/or amplifying host in the epidemiology of spotted fever in that endemic area. The present study consists in the first serological survey in Gallus gallus domesticus to Rickettsiae-spotted fever group in Brazil.

Maciel, Jonas Fernandes; Krawczak, Felipe da Silva; Oliveira, Caroline Sobotyk de; Moraes-Filho, Jonas; Labruna, Marcelo Bahia; Botton, Sônia de Avila; Vogel, Fernanda Silveira Flores; Sangioni, Luis Antonio

2013-01-01

273

Genotypic and biological characteristics of non-identified strain of spotted fever group rickettsiae isolated in Crimea.  

Science.gov (United States)

A strain of rickettsiae, designated Crimea-108, was isolated from ticks Dermacentor marginatus in the Crimea in 1977. Its immunobiological characteristics involve low pathogenicity for experimental animals, moderate infectivity for chick embryos, and antigenic relatedness to spotted fever group (SFG) rickettsiae (R. sibirica, R. conorii, R. akari), especially to R. sibirica. The genotypic characterization of the strain Crimea-108 was carried out in comparison with SFG and typhus group rickettsiae by using restriction fragment length polymorphism (RFLP) analysis and DNA-probe hybridization. The marked similarity was detected between DNA restriction patterns of the strains Crimea-108, R. sibirica and R. conorii, but each of them besides comigrating fragments had specific ones. Genotypic analysis of the strain Crimea-108, the SFG and typhus group rickettsiae by three independent DNA probes, based on R. prowazekii DNA, gave unique hybridization patterns for the Crimea-108 strain with all probes. The obtained data show that the Crimea-108 isolate does not belong to the species of R. sibirica, R. conorii, R. akari. The strain Crimea-108 is a novel strain of SFG rickettsiae for the Crimea region. PMID:7912040

Balayeva, N M; Demkin, V V; Rydkina, E B; Ignatovich, V F; Artemiev, M I; Lichoded LYa; Genig, V A

1993-12-01

274

Genotypic and biological characteristics of non-identified strain of spotted fever group rickettsiae isolated in Crimea.  

UK PubMed Central (United Kingdom)

A strain of rickettsiae, designated Crimea-108, was isolated from ticks Dermacentor marginatus in the Crimea in 1977. Its immunobiological characteristics involve low pathogenicity for experimental animals, moderate infectivity for chick embryos, and antigenic relatedness to spotted fever group (SFG) rickettsiae (R. sibirica, R. conorii, R. akari), especially to R. sibirica. The genotypic characterization of the strain Crimea-108 was carried out in comparison with SFG and typhus group rickettsiae by using restriction fragment length polymorphism (RFLP) analysis and DNA-probe hybridization. The marked similarity was detected between DNA restriction patterns of the strains Crimea-108, R. sibirica and R. conorii, but each of them besides comigrating fragments had specific ones. Genotypic analysis of the strain Crimea-108, the SFG and typhus group rickettsiae by three independent DNA probes, based on R. prowazekii DNA, gave unique hybridization patterns for the Crimea-108 strain with all probes. The obtained data show that the Crimea-108 isolate does not belong to the species of R. sibirica, R. conorii, R. akari. The strain Crimea-108 is a novel strain of SFG rickettsiae for the Crimea region.

Balayeva NM; Demkin VV; Rydkina EB; Ignatovich VF; Artemiev MI; Lichoded LYa; Genig VA

1993-12-01

275

Molecular detection of spotted fever group rickettsia in feral raccoons (Procyon lotor) in the western part of Japan.  

UK PubMed Central (United Kingdom)

Rickettsial infection in feral raccoons (Procyon lotor) in the western part of Japan (Shimane, Fukuoka, Saga and Nagasaki Prefectures) was surveyed by a nested polymerase chain reaction (PCR) assay detecting the rickettsial citrate synthase (gltA) gene. Four of one hundred and ninety-four feral raccoon spleens (2.1%) were positive for Rickettsia spp. One gltA gene sequence was identical to R. helvetica, whereas the other 3 sequences were identical and had the highest similarity (98.4%) to R. amblyommii. Simultaneously, we determined a partial sequence of the rickettsial 17-kilodalton (17K) genus-common antigen gene in the later 3 raccoon samples. Their sequences were identical and had the highest similarity (98.5%) to Rickettsia sp. Hj126. Based on the sequences of gltA and 17K antigen genes, these raccoons might be infected with spotted fever group (SFG) rickettsia most closely related to R. amblyommii and/or Rickettsia sp. Hj126. Feral raccoons may be a susceptible reservoir for SFG rickettsiae in Japan.

Baba K; Kaneda T; Nishimura H; Sato H

2013-02-01

276

Differentiation among spotted fever group rickettsiae species by analysis of restriction fragment length polymorphism of PCR-amplified DNA.  

UK PubMed Central (United Kingdom)

Restriction fragment length polymorphism (RFLP) analysis of PCR-amplified genes was used to study spotted fever group (SFG) rickettsiae, extending the previous work of Regnery et al. (R.L. Regnery, C.L. Spruill, and B.D. Plikaytis, J. Bacteriol. 173:1576-1589, 1991). Twenty-six strains of SFG rickettsia were studied, including several recognized species which have never been studied (R. parkeri, R. helvetica, and R. japonica) as well as strains which are not currently classified. Two previously used primer pairs derived from the R. prowazekii citrate syntase gene and the R. rickettsii 190-kDa protein antigen gene were studied, as were primer pairs obtained from the R. rickettsii 120-kDa protein antigen gene. By using three amplifications and three enzyme digestions, it was possible to differentiate between almost all of the known SFG rickettsia species and to differentiate between several strains of the R. conorii complex. Two human pathogens, "R. africae" and the Israeli tick typhus rickettsia, were first separated by using BG-12 pair primer amplification and then RsaI restriction endonuclease digestion. The proposed simplified model of identification may be useful in studying the geographical distributions of SFG rickettsiae.

Eremeeva M; Yu X; Raoult D

1994-03-01

277

Infrequency of Rickettsia rickettsii in Dermacentor variabilis removed from humans, with comments on the role of other human-biting ticks associated with spotted fever group Rickettsiae in the United States.  

UK PubMed Central (United Kingdom)

From 1997 to 2009, the Tick-Borne Disease Laboratory of the U.S. Army Public Health Command (USAPHC) (formerly the U.S. Army Center for Health Promotion and Preventive Medicine) screened 5286 Dermacentor variabilis ticks removed from Department of Defense (DOD) personnel, their dependents, and DOD civilian personnel for spotted fever group rickettsiae using polymerase chain reaction and restriction fragment length polymorphism analysis. Rickettsia montanensis (171/5286 = 3.2%) and Rickettsia amblyommii (7/5286 = 0.1%) were detected in a small number of samples, but no ticks were found positive for Rickettsia rickettsii, the agent of Rocky Mountain spotted fever (RMSF) until May 2009, when it was detected in one D. variabilis male removed from a child in Maryland. This result was confirmed by nucleotide sequence analysis of the rickettsial isolate and of the positive control used in the polymerase chain reaction, which was different from the isolate. Lethal effects of rickettsiostatic proteins of D. variabilis on R. rickettsii and lethal effects of R. rickettsii infection on tick hosts may account for this extremely low prevalence. Recent reports of R. rickettsii in species Rhipicephalus sanguineus and Amblyomma americanum ticks suggest their involvement in transmission of RMSF, and other pathogenic rickettsiae have been detected in Amblyomma maculatum. The areas of the U.S. endemic for RMSF are also those where D. variabilis exist in sympatry with populations of A. americanum and A. maculatum. Interactions among the sympatric species of ticks may be involved in the development of a focus of RMSF transmission. On the other hand, the overlap of foci of RMSF cases and areas of A. americanum and A. maculatum populations might indicate the misdiagnosis as RMSF of diseases actually caused by other rickettsiae vectored by these ticks. Further studies on tick vectors are needed to elucidate the etiology of RMSF.

Stromdahl EY; Jiang J; Vince M; Richards AL

2011-07-01

278

Rickettsia rickettsii isolation from naturally infected Amblyomma parvum ticks by centrifugation in a 24-well culture plate technique  

Directory of Open Access Journals (Sweden)

Full Text Available Rocky Mountain spotted fever is an acute illness caused by Rickettsia rickettsii (R. rickettsii) and is transmitted by the bite of ticks of the genera Dermacentor, Amblyomma and Rhipicephalus. The illness results in a high mortality rate and may be easily confused with other febrile syndromes. In Yucatan State, Mexico, childhood cases with a high mortality have been reported. In this work we report the isolation of a Mexican R. rickettsii strain from a tick egg mass using an alternative method for Rickettsia isolation with 24-well plates. We also identified a potential vector of R. rickettsii in the southeast of Mexico, which is Amblyomma parvum.

K. Dzul-Rosado; G. Peniche-Lara; R. Tello-Martín; J. Zavala-Velázquez; R. de Campos Pacheco; M.B. Labruna; E.C. Sánchez; J. Zavala-Castro

2013-01-01

279

The influence of temperature and pH on the growth of Rickettsia conorii in irradiated mammalian cells  

International Nuclear Information System (INIS)

The temperature range for optimum growth of Rickettsia conorii in suspension culture of gamma-irradiated L cells was 32 to 38 degC, resulting in rickettsial doubling times between 4.1 and 6.0 hrs. An asynchronous release of Rickettsia conorii from host cells was suggested by the constant increase in percent cells infected over a 36 hrs period. Rickettsial growth was optimal at neutral to slightly alkaline extracellular pH levels. A moderately acidic pH, however, resulted in an increase in doubling time from 4.1 to 7.8 hrs. (author).

1979-01-01

280

Complementation of Rickettsia rickettsii RelA/SpoT restores a nonlytic plaque phenotype.  

UK PubMed Central (United Kingdom)

Spotted fever group rickettsiae are known to produce distinct plaque phenotypes. Strains that cause lytic infections in cell culture form clear plaques, while nonlytic strains form opaque plaques in which the cells remain intact. Clear plaques have historically been associated with more-virulent species or strains of spotted fever group rickettsiae. We have selected spontaneous mutant pairs from two independent strains of Rickettsia rickettsii, the virulent R strain and the avirulent Iowa strain. A nonlytic variant of R. rickettsii R, which typically produces clear plaques, was isolated and stably maintained. A lytic variant of the Iowa strain, which characteristically produces opaque plaques, was also selected and maintained. Genomic resequencing of the variants identified only a single gene disrupted in each strain. In both cases, the mutation was in a gene annotated as relA/spoT-like. In the Iowa strain, a single mutation introduced a premature stop codon upstream from region encoding the predicted active site of RelA/SpoT and caused the transition to a lytic plaque phenotype. In R. rickettsii R, the nonlytic plaque phenotype resulted from a single-nucleotide substitution that shifted a tyrosine residue to histidine near the active site of the enzyme. The intact relA/spoT gene thus occurred in variants with the nonlytic plaque phenotype. Complementation of the truncated relA/spoT gene in the Iowa lytic plaque variant restored the nonlytic phenotype. The relA/spoT mutations did not affect the virulence of either strain in a Guinea pig model of infection; R strain lytic and nonlytic variants both induced fever equally, and the mutation in Iowa to a lytic phenotype did not cause them to become virulent.

Clark TR; Ellison DW; Kleba B; Hackstadt T

2011-04-01

 
 
 
 
281

Experimental infection of dogs with a Brazilian strain of Rickettsia rickettsii: clinical and laboratory findings  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The bacterium Rickettsia rickettsii is the etiological agent of an acute, severe disease called Rocky Mountain spotted fever in the United States or Brazilian spotted fever (BSF) in Brazil. In addition to these two countries, the disease has also been reported to affect humans in Mexico, Costa Rica, Panama, Colombia and Argentina. Like humans, dogs are also susceptible to R. rickettsii infection. However, despite the wide distribution of R. rickettsii in the Western Hemis (more) phere, reports of R. rickettsii-induced illness in dogs has been restricted to the United States. The present study evaluated the pathogenicity for dogs of a South American strain of R. rickettsii. Three groups of dogs were evaluated: group 1 (G1) was inoculated ip with R. rickettsii; group 2 (G2) was infested by R. rickettsii-infected ticks; and the control group (G3) was infested by uninfected ticks. During the study, no clinical abnormalities, Rickettsia DNA or R. rickettsii-reactive antibodies were detected in G3. In contrast, all G1 and G2 dogs developed signs of rickettsial infection, i.e., fever, lethargy, anorexia, ocular lesions, thrombocytopenia, anemia and detectable levels of Rickettsia DNA and R. rickettsii-reactive antibodies in their blood. Rickettsemia started 3-8 days after inoculation or tick infestation and lasted for 3-13 days. Our results indicate that a Brazilian strain of R. rickettsii is pathogenic for dogs, suggesting that canine clinical illness due to R. rickettsii has been unreported in Brazil and possibly in the other South American countries where BSF has been reported among humans.

Piranda, Eliane M; Faccini, João Luis H; Pinter, Adriano; Saito, Tais B; Pacheco, Richard C; Hagiwara, Mitika K; Labruna, Marcelo B

2008-11-01

282

Experimental infection of dogs with a Brazilian strain of Rickettsia rickettsii: clinical and laboratory findings  

Directory of Open Access Journals (Sweden)

Full Text Available The bacterium Rickettsia rickettsii is the etiological agent of an acute, severe disease called Rocky Mountain spotted fever in the United States or Brazilian spotted fever (BSF) in Brazil. In addition to these two countries, the disease has also been reported to affect humans in Mexico, Costa Rica, Panama, Colombia and Argentina. Like humans, dogs are also susceptible to R. rickettsii infection. However, despite the wide distribution of R. rickettsii in the Western Hemisphere, reports of R. rickettsii-induced illness in dogs has been restricted to the United States. The present study evaluated the pathogenicity for dogs of a South American strain of R. rickettsii. Three groups of dogs were evaluated: group 1 (G1) was inoculated ip with R. rickettsii; group 2 (G2) was infested by R. rickettsii-infected ticks; and the control group (G3) was infested by uninfected ticks. During the study, no clinical abnormalities, Rickettsia DNA or R. rickettsii-reactive antibodies were detected in G3. In contrast, all G1 and G2 dogs developed signs of rickettsial infection, i.e., fever, lethargy, anorexia, ocular lesions, thrombocytopenia, anemia and detectable levels of Rickettsia DNA and R. rickettsii-reactive antibodies in their blood. Rickettsemia started 3-8 days after inoculation or tick infestation and lasted for 3-13 days. Our results indicate that a Brazilian strain of R. rickettsii is pathogenic for dogs, suggesting that canine clinical illness due to R. rickettsii has been unreported in Brazil and possibly in the other South American countries where BSF has been reported among humans.

Eliane M Piranda; João Luis H Faccini; Adriano Pinter; Tais B Saito; Richard C Pacheco; Mitika K Hagiwara; Marcelo B Labruna

2008-01-01

283

Rickettsia amblyommii Infecting Amblyomma auricularium Ticks in Pernambuco, Northeastern Brazil: Isolation, Transovarial Transmission, and Transstadial Perpetuation.  

UK PubMed Central (United Kingdom)

Abstract This study investigated rickettsial infection in Amblyomma auricularium ticks from the state of Pernambuco, northeastern Brazil. An engorged female of A. auricularium collected from a skunk (Conepatus semistriatus) was sent alive to the laboratory, where the female was found through molecular analysis to be infected by Rickettsia amblyommii. This engorged female oviposited, and its offspring was reared through three consecutive generations, always using tick-naïve rabbits to feed the ticks. PCR performed on five egg pools, 10 larvae, 10 nymphs, and 10 adults of each of the three generations always yielded rickettsial DNA, indicating maintenance of rickettsial infection in the ticks by transstadial and transovarial passages. DNA sequences of random PCR products from eggs, larvae, nymphs, and adults were identified as R. amblyommii. All infested rabbits seroconverted to R. amblyommii antigens at the 21(st) day after infestation, indicating that larvae, nymphs, and adults transmitted R. amblyommii through parasitism. However, no infested rabbit presented fever or any clinical alteration during the experimental period. Rickettsiae were successfully isolated from the two A. auricularium females, and the isolates were established in Vero cell culture. Molecular characterization of the isolates confirmed R. amblyommii by sequencing partial gltA, ompA, and ompB genes. From another sample of 15 A. auricularium adult ticks collected from two armadillos (Euphractus sexcinctus), eight (53.3%) were infected by R. amblyommii. This study reports R. amblyommii infecting the tick A. auricularium for the first time. This is also the first report of rickettsia infecting ticks in the northeastern region of Brazil.

Saraiva DG; Nieri-Bastos FA; Horta MC; Soares HS; Nicola PA; Pereira LC; Labruna MB

2013-05-01

284

Rickettsia amblyommii Infecting Amblyomma auricularium Ticks in Pernambuco, Northeastern Brazil: Isolation, Transovarial Transmission, and Transstadial Perpetuation.  

Science.gov (United States)

Abstract This study investigated rickettsial infection in Amblyomma auricularium ticks from the state of Pernambuco, northeastern Brazil. An engorged female of A. auricularium collected from a skunk (Conepatus semistriatus) was sent alive to the laboratory, where the female was found through molecular analysis to be infected by Rickettsia amblyommii. This engorged female oviposited, and its offspring was reared through three consecutive generations, always using tick-naïve rabbits to feed the ticks. PCR performed on five egg pools, 10 larvae, 10 nymphs, and 10 adults of each of the three generations always yielded rickettsial DNA, indicating maintenance of rickettsial infection in the ticks by transstadial and transovarial passages. DNA sequences of random PCR products from eggs, larvae, nymphs, and adults were identified as R. amblyommii. All infested rabbits seroconverted to R. amblyommii antigens at the 21(st) day after infestation, indicating that larvae, nymphs, and adults transmitted R. amblyommii through parasitism. However, no infested rabbit presented fever or any clinical alteration during the experimental period. Rickettsiae were successfully isolated from the two A. auricularium females, and the isolates were established in Vero cell culture. Molecular characterization of the isolates confirmed R. amblyommii by sequencing partial gltA, ompA, and ompB genes. From another sample of 15 A. auricularium adult ticks collected from two armadillos (Euphractus sexcinctus), eight (53.3%) were infected by R. amblyommii. This study reports R. amblyommii infecting the tick A. auricularium for the first time. This is also the first report of rickettsia infecting ticks in the northeastern region of Brazil. PMID:23705586

Saraiva, Danilo G; Nieri-Bastos, Fernanda A; Horta, Maurício C; Soares, Herbert S; Nicola, Patricia A; Pereira, Luiz Cezar M; Labruna, Marcelo B

2013-05-24

285

Susceptibility of Rickettsia conorii and R. rickettsii to pefloxacin, in vitro and in ovo.  

UK PubMed Central (United Kingdom)

The activity of pefloxacin against Rickettsia conorii and R. rickettsii was determined by several methods. The mean survival time of embryonated eggs infected with R. conorii was increased by pefloxacin 50 micrograms/egg; plaque formation in Vero cells was inhibited by 1 mg/l. In a microplate assay, the MIC of pefloxacin was 0.5 mg/l for R. conorii and 1 mg/l for R. rickettsii. The results support the use of pefloxacin in treating spotted fever rickettsioses.

Raoult D; Roussellier P; Vestris G; Galicher V; Perez R; Tamalet J

1987-03-01

286

Septic shock in a patient infected with Rickettsia sibirica mongolitimonae, Spain.  

UK PubMed Central (United Kingdom)

In 1996, the first human case of infection by Rickettsia sibirica subsp. mongolitimonae was described in France. Subsequently, other human cases were reported in the same country. The acronym LAR (lymphangitis-associated rickettsiosis) has been proposed to designate this disease because lymphangitis is one of the main clinical manifestations. Later, a few more cases were described in Portugal, South Africa, Egypt, Greece and Spain. We report a case of R. sibirica mongolitimonae infection as a cause of septic shock in a Spanish patient living in La Rioja (northern Spain). In addition, the broad clinical spectrum of this tick-borne disease is discussed.

Ibarra V; Portillo A; Palomar AM; Sanz MM; Metola L; Blanco JR; Oteo JA

2012-08-01

287

[Nest ectoparasites (gamasid mites) as vectors for rickettsia under experimental conditions].  

Science.gov (United States)

The author gives a review of occurrence of rickettsiae (Coxiella burnetii, R. slovaca, R. sibirica, R. prowazekii, R. mooseri, R. akari) in gamasid mites, investigated in laboratory or in nature. The results of our experiments and from literature also are summarized in tables. The experimental infection with C. burnetii was investigated by natural route of infection in the following species of mites: Haemogamasus nidi, H. hirsutus, Androlaelaps casalis. We found C. burnetii in smears, stained with Gimenez and IMF, with whole bodies as well as in their excrements. The white mice injected with the suspension from these mites gave the positive serological response. PMID:2485310

Kocianová, E

1989-01-01

288

[Nest ectoparasites (gamasid mites) as vectors for rickettsia under experimental conditions  

UK PubMed Central (United Kingdom)

The author gives a review of occurrence of rickettsiae (Coxiella burnetii, R. slovaca, R. sibirica, R. prowazekii, R. mooseri, R. akari) in gamasid mites, investigated in laboratory or in nature. The results of our experiments and from literature also are summarized in tables. The experimental infection with C. burnetii was investigated by natural route of infection in the following species of mites: Haemogamasus nidi, H. hirsutus, Androlaelaps casalis. We found C. burnetii in smears, stained with Gimenez and IMF, with whole bodies as well as in their excrements. The white mice injected with the suspension from these mites gave the positive serological response.

Kocianová E

1989-01-01

289

Restriction endonuclease analysis of the DNA of Rickettsia prowazekii vaccine strain E and its revertant.  

Science.gov (United States)

The DNA of Rickettsia prowazekii vaccine strain E was analysed by restriction analysis with 17 endonucleases in comparison with its virulent revertant - Evir and the virulent reference strain Breinl. The DNA of cloned and uncloned strains showed identical restriction endonuclease patterns. In spite of stable differences in virulence, strains E and Evir displayed a totally identical DNA cleavage pattern indicating the absence of marked structural differences between their genomes. On the other hand 9 endonucleases showed differences in the restrictograms of the DNA strain Breinl as compared with strains E and Evir. PMID:2576585

Balaeva, N M; Rydkina, E B; Artemiev, M I; Ignatovich, V F

1989-09-01

290

Restriction endonuclease analysis of the DNA of Rickettsia prowazekii vaccine strain E and its revertant.  

UK PubMed Central (United Kingdom)

The DNA of Rickettsia prowazekii vaccine strain E was analysed by restriction analysis with 17 endonucleases in comparison with its virulent revertant - Evir and the virulent reference strain Breinl. The DNA of cloned and uncloned strains showed identical restriction endonuclease patterns. In spite of stable differences in virulence, strains E and Evir displayed a totally identical DNA cleavage pattern indicating the absence of marked structural differences between their genomes. On the other hand 9 endonucleases showed differences in the restrictograms of the DNA strain Breinl as compared with strains E and Evir.

Balaeva NM; Rydkina EB; Artemiev MI; Ignatovich VF

1989-09-01

291

Rickettsia typhi possesses phospholipase A2 enzymes that are involved in infection of host cells.  

Science.gov (United States)

The long-standing proposal that phospholipase A2 (PLA2) enzymes are involved in rickettsial infection of host cells has been given support by the recent characterization of a patatin phospholipase (Pat2) with PLA2 activity from the pathogens Rickettsia prowazekii and R. typhi. However, pat2 is not encoded in all Rickettsia genomes; yet another uncharacterized patatin (Pat1) is indeed ubiquitous. Here, evolutionary analysis of both patatins across 46 Rickettsia genomes revealed 1) pat1 and pat2 loci are syntenic across all genomes, 2) both Pat1 and Pat2 do not contain predicted Sec-dependent signal sequences, 3) pat2 has been pseudogenized multiple times in rickettsial evolution, and 4) ubiquitous pat1 forms two divergent groups (pat1A and pat1B) with strong evidence for recombination between pat1B and plasmid-encoded homologs. In light of these findings, we extended the characterization of R. typhi Pat1 and Pat2 proteins and determined their role in the infection process. As previously demonstrated for Pat2, we determined that 1) Pat1 is expressed and secreted into the host cytoplasm during R. typhi infection, 2) expression of recombinant Pat1 is cytotoxic to yeast cells, 3) recombinant Pat1 possesses PLA2 activity that requires a host cofactor, and 4) both Pat1 cytotoxicity and PLA2 activity were reduced by PLA2 inhibitors and abolished by site-directed mutagenesis of catalytic Ser/Asp residues. To ascertain the role of Pat1 and Pat2 in R. typhi infection, antibodies to both proteins were used to pretreat rickettsiae. Subsequent invasion and plaque assays both indicated a significant decrease in R. typhi infection compared to that by pre-immune IgG. Furthermore, antibody-pretreatment of R. typhi blocked/delayed phagosomal escapes. Together, these data suggest both enzymes are involved early in the infection process. Collectively, our study suggests that R. typhi utilizes two evolutionary divergent patatin phospholipases to support its intracellular life cycle, a mechanism distinguishing it from other rickettsial species. PMID:23818842

Rahman, M Sayeedur; Gillespie, Joseph J; Kaur, Simran Jeet; Sears, Khandra T; Ceraul, Shane M; Beier-Sexton, Magda; Azad, Abdu F

2013-06-20

292

Rickettsia typhi possesses phospholipase A2 enzymes that are involved in infection of host cells.  

UK PubMed Central (United Kingdom)

The long-standing proposal that phospholipase A2 (PLA2) enzymes are involved in rickettsial infection of host cells has been given support by the recent characterization of a patatin phospholipase (Pat2) with PLA2 activity from the pathogens Rickettsia prowazekii and R. typhi. However, pat2 is not encoded in all Rickettsia genomes; yet another uncharacterized patatin (Pat1) is indeed ubiquitous. Here, evolutionary analysis of both patatins across 46 Rickettsia genomes revealed 1) pat1 and pat2 loci are syntenic across all genomes, 2) both Pat1 and Pat2 do not contain predicted Sec-dependent signal sequences, 3) pat2 has been pseudogenized multiple times in rickettsial evolution, and 4) ubiquitous pat1 forms two divergent groups (pat1A and pat1B) with strong evidence for recombination between pat1B and plasmid-encoded homologs. In light of these findings, we extended the characterization of R. typhi Pat1 and Pat2 proteins and determined their role in the infection process. As previously demonstrated for Pat2, we determined that 1) Pat1 is expressed and secreted into the host cytoplasm during R. typhi infection, 2) expression of recombinant Pat1 is cytotoxic to yeast cells, 3) recombinant Pat1 possesses PLA2 activity that requires a host cofactor, and 4) both Pat1 cytotoxicity and PLA2 activity were reduced by PLA2 inhibitors and abolished by site-directed mutagenesis of catalytic Ser/Asp residues. To ascertain the role of Pat1 and Pat2 in R. typhi infection, antibodies to both proteins were used to pretreat rickettsiae. Subsequent invasion and plaque assays both indicated a significant decrease in R. typhi infection compared to that by pre-immune IgG. Furthermore, antibody-pretreatment of R. typhi blocked/delayed phagosomal escapes. Together, these data suggest both enzymes are involved early in the infection process. Collectively, our study suggests that R. typhi utilizes two evolutionary divergent patatin phospholipases to support its intracellular life cycle, a mechanism distinguishing it from other rickettsial species.

Rahman MS; Gillespie JJ; Kaur SJ; Sears KT; Ceraul SM; Beier-Sexton M; Azad AF

2013-06-01

293

Tuberculosis ganglionar a forma de fiebre de origen desconocido: a propósito de un caso Ganglionary tuberculosis as fever of unknown origin: apropos of a case  

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Full Text Available La tuberculosis, tanto en su forma pulmonar como extrapulmonar constituye una enfermedad reemergente al nivel mundial, asociada con insuficiencias de los programas de control sanitario o con el síndrome de inmunodeficiencia adquirida. El modo de presentación de las formas extrapulmonares se relaciona con síntomas constitucionales, que incluyen la fiebre y con signos dependientes del órgano afectado. Se presentó el caso de una adenitis granulomatosa en etapa o categoría 3, grupo integrado por aquellos casos nuevos de formas menos grave de tuberculosis extrapulmonar (TBe) con confirmación histopatológica del bacilo. Se enfatizó sobre la presentación a forma de fiebre de origen desconocido (FOD), al reunir los criterios necesarios por haber estado ingresada en otro centro hospitalario por más de 1 mes, sin haber llegado al diagnóstico a pesar de haber sido estudiada, y se resaltó la necesidad imperiosa de la búsqueda de este diagnóstico ante todo paciente con cuadro adénico febril e historia familiar de TB.Tuberculosis, both in its pulmonary and extrapulmonary form is a reemerging disease in the world associated with insufficiencies of the health control programs or with the acquired immunodeficiency syndrome. The mode of presentation of the extrapulmonary forms is related to constitutional symptoms that include fever, and to signs depending on the affected organ. The case of a stage III granulomatous adenitis, a group composed of those new cases of less severe forms of extrapulmonary tuberculosis with histopathological confirmation of the bacillus, was presented. Emphasis was made on the presentation as a FUO, on having the necessary criteria for having been admitted in another hospital for more than a month without a definitive diagnosis despite having been studied. The pressing need to search this diagnosis in every patient with febrile adenic picture and family history of TB was stressed.

Manuel A. Fernández Arias; Alfredo Vázquez Vigoa; Julieta Sánchez Ruiz; Julio César Pérez Suárez

2007-01-01

294

Molecular characterization of mediterranean spotted fever rickettsia isolated from a European traveler in the state of Sao Paulo, Brazil.  

UK PubMed Central (United Kingdom)

Rickettsial spotted fever is common in southeastern Brazil. Differential diagnosis of pathogens can be performed with proper laboratory methods. A traveler arriving from Portugal developed a fatal febrile hemorrhagic syndrome diagnosed as spotted fever rickettsiosis. We isolated the agent, which was identified as Rickettsia conorii conorii by sequencing rickettsial genes.

Gehrke FS; Angerami RN; Marrelli MT; de Souza ER; do Nascimento EM; Colombo S; da Silva LJ; Schumaker TT

2013-01-01

295

Neutralizing activity of monoclonal antibodies to heat-sensitive and heat-resistant epitopes of Rickettsia rickettsii surface proteins.  

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Antiprotein monoclonal antibodies derived from mice inoculated with Rickettsia rickettsii heated at 56 degrees C for 15 min are of two types: one is type specific for epitopes denatured by moderate temperatures, and the other is specific for epitopes resistant to 100 degrees C for 5 min. The heat-re...

Anacker, R L; McDonald, G A; List, R H; Mann, R E

296

In vitro effectiveness of azithromycin against doxycycline-resistant and -susceptible strains of Rickettsia tsutsugamushi, etiologic agent of scrub typhus.  

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In an effort to find a potential alternative treatment for scrub typhus, we evaluated the effectiveness of the standard drug doxycycline and the new macrolide azithromycin against a doxycycline-susceptible strain (Karp) and a doxycycline-resistant strain (AFSC-4) of Rickettsia tsutsugamushi. The ant...

Strickman, D; Sheer, T; Salata, K; Hershey, J; Dasch, G; Kelly, D; Kuschner, R

297

Molecular identification of Rickettsia felis in ticks and fleas from an endemic area for Brazilian Spotted Fever  

Directory of Open Access Journals (Sweden)

Full Text Available Rickettsioses are arthropod-borne diseases caused by parasites from the Order Rickettsiales. The most prevalent rickettsial disease in Brazil is Brazilian Spotted Fever (BSF). This work intends the molecular detection of those agents in ectoparasites from an endemic area of BSF in the state of Espírito Santo. A total of 502 ectoparasites, among them Amblyomma cajennense, Amblyomma dubitatum (A. cooperi), Riphicephalus sanguineus, Anocentor nitens and Ctenocephalides felis, was collected from domestic animals and the environment and separated in 152 lots according to the origin. Rickettsia sp. was detected in pools of all collected species by amplification of 17kDa protein-encoding gene fragments. The products of PCR amplification of three samples were sequenced, and Rickettsia felis was identified in R. sanguineus and C. felis. These results confirm the presence of Rickettsia felis in areas previously known as endemic for BSF, disease caused by Rickettsia rickettsii. Moreover, they show the needing of further studies for deeper knowledge of R. felis-spotted fever epidemiology and differentiation of these diseases in Brazil.

KA Oliveira; LS Oliveira; CCA Dias; A Silva Jr; MR Almeida; G Almada; DH Bouyer; MAM Galvão; CL Mafra

2008-01-01

298

Analysis of Leptospira spp., Leptonema illini, and Rickettsia rickettsii for the 39-kilodalton antigen (P39) of Borrelia burgdorferi.  

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Five serovars of Leptospira interrogans, Leptospira biflexa, Leptonema illini, and Rickettsia rickettsii were examined and found not to contain the 39-kDa antigen (P39) of Borrelia burgdorferi, the Lyme disease spirochete. The specificity of this antigen and its reactivity with human Lyme disease se...

Schwan, T G; Schrumpf, M E; Gage, K L; Gilmore, R D

299

Molecular Detection of Rickettsia felis, Bartonella henselae, and B. clarridgeiae in Fleas from Domestic Dogs and Cats in Malaysia  

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The presence of Rickettsia felis, Bartonella henselae and B. clarridgeiae in 209 fleas (Ctenocephalides felis) obtained from domestic cats and dogs in several locations in Malaysia was investigated in this study. Using a polymerase chain reaction specific for the citrate synthase (gltA) and 17-kD an...

Mokhtar, Aida Syafinaz; Tay, Sun Tee

300

Molecular detection of Rickettsia felis in different flea species from Caldas, Colombia.  

UK PubMed Central (United Kingdom)

Rickettsioses caused by Rickettsia felis are an emergent global threat. Historically, the northern region of the province of Caldas in Colombia has reported murine typhus cases, and recently, serological studies confirmed high seroprevalence for both R. felis and R. typhi. In the present study, fleas from seven municipalities were collected from dogs, cats, and mice. DNA was extracted and amplified by polymerase chain reaction (PCR) to identify gltA, ompB, and 17kD genes. Positive samples were sequenced to identify the species of Rickettsia. Of 1,341 fleas, Ctenocephalides felis was the most prevalent (76.7%). Positive PCR results in the three genes were evidenced in C. felis (minimum infection rates; 5.3%), C. canis (9.2%), and Pulex irritans (10.0%). Basic Local Alignment Search Tool (BLAST) analyses of sequences showed high identity values (> 98%) with R. felis, and all were highly related by phylogenetic analyses. This work shows the first detection of R. felis in fleas collected from animals in Colombia.

Ramírez-Hernández A; Montoya V; Martínez A; Pérez JE; Mercado M; de la Ossa A; Vélez C; Estrada G; Correa MI; Duque L; Ariza JS; Henao C; Valbuena G; Hidalgo M

2013-09-01

 
 
 
 
301

Spotted fever group rickettsiae in ticks and fleas from the Democratic Republic of the Congo.  

Science.gov (United States)

Little is known about the prevalence of spotted fever group (SFG) rickettsiae in ticks and fleas in the Democratic Republic of the Congo. In 2008, 12 Amblyomma compressum ticks were collected from 3 pangolins (Manis gigantea). Two Haemaphysalis punctaleachi ticks were collected from 2 African civets (Civettictis civetta congica), and one was collected from an antelope (Onotragus leche). A total of 111 Rhipicephalus sanguineus ticks, 23 Ctenocephalides canis fleas, 39 C. felis fleas, and 5 Trichodectes canis lice were sampled from 19 dogs. One C. canis flea was collected from a human. Six of the 12 A. compressum ticks were positive for rickettsial DNA, as determined by genus-specific qPCR. The ompA gene sequences amplified from positive samples showed 100% homology with Rickettsia africae (GenBank accession number CP001612). The detection of Ri. africae in A. compressum ticks, which are highly specialized parasites of pangolins, is consistent with our previous data showing the presence of Ri. africae in A. compressum ticks from Liberia. No other ticks contained rickettsial DNA. A total of 9 C. canis fleas (39%, 9/23) and 37 C. felis fleas (95%, 37/39) that was collected from dogs and one C. canis flea collected from a human harbored Ri. felis. PMID:23137572

Mediannikov, Oleg; Davoust, Bernard; Socolovschi, Cristina; Tshilolo, Léon; Raoult, Didier; Parola, Philippe

2012-10-22

302

Spotted fever group rickettsiae in ticks and fleas from the Democratic Republic of the Congo.  

UK PubMed Central (United Kingdom)

Little is known about the prevalence of spotted fever group (SFG) rickettsiae in ticks and fleas in the Democratic Republic of the Congo. In 2008, 12 Amblyomma compressum ticks were collected from 3 pangolins (Manis gigantea). Two Haemaphysalis punctaleachi ticks were collected from 2 African civets (Civettictis civetta congica), and one was collected from an antelope (Onotragus leche). A total of 111 Rhipicephalus sanguineus ticks, 23 Ctenocephalides canis fleas, 39 C. felis fleas, and 5 Trichodectes canis lice were sampled from 19 dogs. One C. canis flea was collected from a human. Six of the 12 A. compressum ticks were positive for rickettsial DNA, as determined by genus-specific qPCR. The ompA gene sequences amplified from positive samples showed 100% homology with Rickettsia africae (GenBank accession number CP001612). The detection of Ri. africae in A. compressum ticks, which are highly specialized parasites of pangolins, is consistent with our previous data showing the presence of Ri. africae in A. compressum ticks from Liberia. No other ticks contained rickettsial DNA. A total of 9 C. canis fleas (39%, 9/23) and 37 C. felis fleas (95%, 37/39) that was collected from dogs and one C. canis flea collected from a human harbored Ri. felis.

Mediannikov O; Davoust B; Socolovschi C; Tshilolo L; Raoult D; Parola P

2012-12-01

303

Disruption of the Rickettsia rickettsii Sca2 autotransporter inhibits actin-based motility.  

UK PubMed Central (United Kingdom)

Rickettsii rickettsii, the etiologic agent of Rocky Mountain spotted fever, replicates within the cytosol of infected cells and uses actin-based motility to spread inter- and intracellularly. Although the ultrastructure of the actin tail and host proteins associated with it are distinct from those of Listeria or Shigella, comparatively little is known regarding the rickettsial proteins involved in its organization. Here, we have used random transposon mutagenesis of R. rickettsii to generate a small-plaque mutant that is defective in actin-based motility and does not spread directly from cell to cell as is characteristic of spotted fever group rickettsiae. The transposon insertion site of this mutant strain was within Sca2, a member of a family of large autotransporter proteins. Sca2 exhibits several features suggestive of its apparent role in actin-based motility. It displays an N-terminal secretory signal peptide, a C-terminal predicted autotransporter domain, up to four predicted Wasp homology 2 (WH2) domains, and two proline-rich domains, one with similarity to eukaryotic formins. In a guinea pig model of infection, the Sca2 mutant did not elicit fever, suggesting that Sca2 and actin-based motility are virulence factors of spotted fever group rickettsiae.

Kleba B; Clark TR; Lutter EI; Ellison DW; Hackstadt T

2010-05-01

304

Molecular detection of Rickettsia felis in different flea species from Caldas, Colombia.  

Science.gov (United States)

Rickettsioses caused by Rickettsia felis are an emergent global threat. Historically, the northern region of the province of Caldas in Colombia has reported murine typhus cases, and recently, serological studies confirmed high seroprevalence for both R. felis and R. typhi. In the present study, fleas from seven municipalities were collected from dogs, cats, and mice. DNA was extracted and amplified by polymerase chain reaction (PCR) to identify gltA, ompB, and 17kD genes. Positive samples were sequenced to identify the species of Rickettsia. Of 1,341 fleas, Ctenocephalides felis was the most prevalent (76.7%). Positive PCR results in the three genes were evidenced in C. felis (minimum infection rates; 5.3%), C. canis (9.2%), and Pulex irritans (10.0%). Basic Local Alignment Search Tool (BLAST) analyses of sequences showed high identity values (> 98%) with R. felis, and all were highly related by phylogenetic analyses. This work shows the first detection of R. felis in fleas collected from animals in Colombia. PMID:23878183

Ramírez-Hernández, Alejandro; Montoya, Viviana; Martínez, Alejandra; Pérez, Jorge E; Mercado, Marcela; de la Ossa, Alberto; Vélez, Carolina; Estrada, Gloria; Correa, Maria I; Duque, Laura; Ariza, Juan S; Henao, Cesar; Valbuena, Gustavo; Hidalgo, Marylin

2013-07-22

305

Genome-wide screen for temperature-regulated genes of the obligate intracellular bacterium, Rickettsia typhi  

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Full Text Available Abstract Background The ability of rickettsiae to survive in multiple eukaryotic host environments provides a good model for studying pathogen-host molecular interactions. Rickettsia typhi, the etiologic agent of murine typhus, is a strictly intracellular gram negative ?-proteobacterium, which is transmitted to humans by its arthropod vector, the oriental rat flea, Xenopsylla cheopis. Thus, R. typhi must cycle between mammalian and flea hosts, two drastically different environments. We hypothesize that temperature plays a role in regulating host-specific gene expression, allowing R. typhi to survive in mammalian and arthropod hosts. In this study, we used Affymetrix microarrays to screen for temperature-induced genes upon a temperature shift from 37°C to 25°C, mimicking the two different host temperatures in vitro. Results Temperature-responsive genes belonged to multiple functional categories including among others, transcription, translation, posttranslational modification/protein turnover/chaperones and intracellular trafficking and secretion. A large number of differentially expressed genes are still poorly characterized, and either have no known function or are not in the COG database. The microarray results were validated with quantitative real time RT-PCR. Conclusion This microarray screen identified various genes that were differentially expressed upon a shift in temperature from 37°C to 25°C. Further characterization of the identified genes may provide new insights into the ability of R. typhi to successfully transition between its mammalian and arthropod hosts.

Dreher-Lesnick Sheila M; Ceraul Shane M; Rahman M Sayeedur; Azad Abdu F

2008-01-01

306

Infections with Wolbachia, Spiroplasma, and Rickettsia in the Dolichopodidae and other Empidoidea.  

UK PubMed Central (United Kingdom)

Vertically transmitted reproductive parasites are both extraordinarily widespread and diverse in their effects on their invertebrate hosts. In addition to causing skewed population sex ratios via male-killing or feminization, such bacteria can further cause cytoplasmic incompatibility or parthenogenesis. Previous surveys show that the microbes Wolbachia and Spiroplasma are common in some dipteran families, e.g. Drosophilidae or Scathophagidae, and are known to be heritable symbionts and affect reproduction in the Diptera. However, little is known of Rickettsia infections and detailed surveys targeting other Dipteran families are lacking. Here 329 samples of 247 species of Diptera belonging to the Dolichopodidae, Empididae, and Hybotidae (superfamily Empidoidea) are surveyed for the presence of the endosymbionts Wolbachia, Spiroplasma, and Rickettsia. The superfamily Empidoidea contains numerous species, which have been the targets of intense research concerning reproductive traits involved in sexual selection. 151 of the species (i.e. ca. 61%) screened here, including species from key genera such as Dolichopus, Poecilobothrus or Empis, harboured one or more symbionts. Reproductive parasites are thus also common in the Empidoidae, yet effects on hosts remain unclear. Potential endosymbiont-host interactions in this group would hence be worthy of further investigation.

Martin OY; Puniamoorthy N; Gubler A; Wimmer C; Bernasconi MV

2013-01-01

307

Proteome Analysis and Serological Characterization of Surface-Exposed Proteins of Rickettsia heilongjiangensis.  

UK PubMed Central (United Kingdom)

BACKGROUND: Rickettsia heilongjiangensis, the agent of Far-Eastern spotted fever (FESF), is an obligate intracellular bacterium. The surface-exposed proteins (SEPs) of rickettsiae are involved in rickettsial adherence to and invasion of host cells, intracellular bacterial growth, and/or interaction with immune cells. They are also potential molecular candidates for the development of diagnostic reagents and vaccines against rickettsiosis. METHODS: R. heilongjiangensis SEPs were identified by biotin-streptavidin affinity purification and 2D electrophoreses coupled with ESI-MS/MS. Recombinant SEPs were probed with various sera to analyze their serological characteristics using a protein microarray and an enzyme-linked immune sorbent assay (ELISA). RESULTS: Twenty-five SEPs were identified, most of which were predicted to reside on the surface of R. heilongjiangensis cells. Bioinformatics analysis suggests that these proteins could be involved in bacterial pathogenesis. Eleven of the 25 SEPs were recognized as major seroreactive antigens by sera from R. heilongjiangensis-infected mice and FESF patients. Among the major seroreactive SEPs, microarray assays and/or ELISAs revealed that GroEL, OmpA-2, OmpB-3, PrsA, RplY, RpsB, SurA and YbgF had modest sensitivity and specificity for recognizing R. heilongjiangensis infection and/or spotted fever. CONCLUSIONS: Many of the SEPs identified herein have potentially important roles in R. heilongjiangensis pathogenicity. Some of them have potential as serodiagnostic antigens or as subunit vaccine antigens against the disease.

Qi Y; Xiong X; Wang X; Duan C; Jia Y; Jiao J; Gong W; Wen B

2013-01-01

308

Rickettsia Sca2 has evolved formin-like activity through a different molecular mechanism.  

Science.gov (United States)

Sca2 (surface cell antigen 2) is the only bacterial protein known to promote both actin filament nucleation and profilin-dependent elongation, mimicking eukaryotic formins to assemble actin comet tails for Rickettsia motility. We show that Sca2's functional mimicry of formins is achieved through a unique mechanism. Unlike formins, Sca2 is monomeric, but has N- and C-terminal repeat domains (NRD and CRD) that interact with each other for processive barbed-end elongation. The crystal structure of NRD reveals a previously undescribed fold, consisting of helix-loop-helix repeats arranged into an overall crescent shape. CRD is predicted to share this fold and might form together with NRD, a doughnut-shaped formin-like structure. In between NRD and CRD, proline-rich sequences mediate the incorporation of profilin-actin for elongation, and WASP-homology 2 (WH2) domains recruit actin monomers for nucleation. Sca2's ?-helical fold is unusual among Gram-negative autotransporters, which overwhelmingly fold as ?-solenoids. Rickettsia has therefore "rediscovered" formin-like actin nucleation and elongation. PMID:23818602

Madasu, Yadaiah; Suarez, Cristian; Kast, David J; Kovar, David R; Dominguez, Roberto

2013-07-01

309

Isolation and characterization of the dnaA gene of Rickettsia prowazekii  

International Nuclear Information System (INIS)

The dnaA gene encoding the initiator protein of DNA replication was isolated from the obligate intracellular bacterium, Rickettsia prowazekii. Comparison of the deduced amino acid sequence of R. prowazekii DnaA with other bacterial DnaA proteins revealed extensive similarity. However, the rickettsial sequence is unique in the number of basic lysine residues found within a highly conserved portion of the putative DNA binding region, suggesting that the rickettsial protein may recognize a DNA sequence that differs from the consensus DnaA box sequence identified in other bacteria. Consensus DnaA box sequences, found upstream of many bacterial dnaA genes, were not identified upstream of rickettsial dnaA gene. In addition, gene organization within this region differed from that of other bacteria. The putative start of transcription of the rickettsial dnaA gene was localized to a site 522 nucleotides upstream of the DnaA start codon. Key words: Rickettsia prowazekii; dnaA gene; initiator protein (authors)

1998-01-01

310

Rickettsia Sca2 has evolved formin-like activity through a different molecular mechanism.  

UK PubMed Central (United Kingdom)

Sca2 (surface cell antigen 2) is the only bacterial protein known to promote both actin filament nucleation and profilin-dependent elongation, mimicking eukaryotic formins to assemble actin comet tails for Rickettsia motility. We show that Sca2's functional mimicry of formins is achieved through a unique mechanism. Unlike formins, Sca2 is monomeric, but has N- and C-terminal repeat domains (NRD and CRD) that interact with each other for processive barbed-end elongation. The crystal structure of NRD reveals a previously undescribed fold, consisting of helix-loop-helix repeats arranged into an overall crescent shape. CRD is predicted to share this fold and might form together with NRD, a doughnut-shaped formin-like structure. In between NRD and CRD, proline-rich sequences mediate the incorporation of profilin-actin for elongation, and WASP-homology 2 (WH2) domains recruit actin monomers for nucleation. Sca2's ?-helical fold is unusual among Gram-negative autotransporters, which overwhelmingly fold as ?-solenoids. Rickettsia has therefore "rediscovered" formin-like actin nucleation and elongation.

Madasu Y; Suarez C; Kast DJ; Kovar DR; Dominguez R

2013-07-01

311

Serosurvey for tick-borne diseases in dogs from the Eastern Amazon, Brazil/ Pesquisa Sorologica por doencas transmitidas por carrapatos em caes da Amazonia oriental, Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Ehrliquiose canina e babesiose canina são as doenças parasitárias transmitidas por carrapatos de maior prevalência em cães do Brasil. Poucos estudos pesquisaram doenças transmitidas por carrapatos na região da Amazônia brasileira. Um total de 129 amostras de sangue foram colhidas de cães da Amazônia oriental brasileira. Setenta e dois cães eram de áreas rurais de 19 municípios do Estado do Pará, e 57 am (more) ostras foram colhidas de cães errantes vadios da área urbana do município de Santarém-PA. As amostras de soro foram submetidas ao ensaio de imunofluorescência indireta, com antígenos de Babesia canis vogeli, Ehrlichia canis, e seis espécies de Rickettsia. A frequência de cães com anticorpos anti-B. canis vogeli, anti-E. canis, e anti-Rickettsia spp. foi de 42,6%, 16,2% e 31,7%, respectivamente. Anticorpos anti-B. canis vogeli foram detectados em 59,6% dos cães urbanos, e em 29,1% dos cães rurais (P < 0.05). Para E. canis, a soroprevalência foi parecida entre os cães urbanos (15,7%) e rurais (16,6%). Para Rickettsia spp., cães rurais apresentaram prevalência (P < 0.05) significativamente maior (40,3%) do que os cães urbanos (21,1%). Esse primeiro estudo sobre agentes transmitidos por carrapatos entre cães da Amazônia oriental brasileira indica que estes animais estão expostos a vários agentes. Estes incluem Babesia principalmente na área urbana, Riquétsias do grupo da Febre Maculosa principalmente nas áreas rurais, e Erliquia em cães de ambas as áreas, rural e urbana. Abstract in english Canine ehrlichiosis and babesiosis are the most prevalent tick-borne diseases in Brazilian dogs. Few studies have focused attention in surveying tick-borne diseases in the Brazilian Amazon region. A total of 129 blood samples were collected from dogs living in the Brazilian eastern Amazon. Seventy-two samples from dogs from rural areas of 19 municipalities and 57 samples from urban stray dogs from Santarém municipality were collected. Serum samples were submitted to (more) Indirect Immunofluorescence Assay (IFA) with antigens of Babesia canis vogeli, Ehrlichia canis, and six Rickettsia species. The frequency of dogs containing anti-B. canis vogeli, anti-E. canis, and anti-Rickettsia spp. antibodies was 42.6%, 16.2%, and 31.7%, respectively. Anti-B. canis vogeli antibodies were detected in 59.6% of the urban dogs, and in 29.1% of the rural dogs (P < 0.05). For E. canis, seroprevalence was similar among urban (15.7%) and rural (16.6%) dogs. For Rickettsia spp., rural dogs presented significantly higher (P < 0.05) prevalence (40.3%) than urban animals (21.1%). This first study on tick-borne pathogens in dogs from the Brazilian eastern Amazon indicates that dogs are exposed to several agents, such as Babesia organisms, mostly in the urban area; Spotted Fever group Rickettsia organisms, mostly in the rural area; and Ehrlichia organisms, in dogs from both areas studied.

Spolidorio, Mariana Granziera; Minervino, Antonio Humberto Hamad; Valadas, Samantha Yuri Oshiro Branco; Soares, Herbert Sousa; Neves, Kedson Alessandri Lobo; Labruna, Marcelo Bahia; Ribeiro, Mucio Flavio Barbosa; Gennari, Solange Maria

2013-06-01

312

Serosurvey for tick-borne diseases in dogs from the Eastern Amazon, Brazil/ Pesquisa Sorológica por doenças transmitidas por carrapatos em cães da Amazônia oriental, Brasil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Ehrliquiose canina e babesiose canina são as doenças parasitárias transmitidas por carrapatos de maior prevalência em cães do Brasil. Poucos estudos pesquisaram doenças transmitidas por carrapatos na região da Amazônia brasileira. Um total de 129 amostras de sangue foram colhidas de cães da Amazônia oriental brasileira. Setenta e dois cães eram de áreas rurais de 19 municípios do Estado do Pará, e 57 am (more) ostras foram colhidas de cães errantes vadios da área urbana do município de Santarém-PA. As amostras de soro foram submetidas ao ensaio de imunofluorescência indireta, com antígenos de Babesia canis vogeli, Ehrlichia canis, e seis espécies de Rickettsia. A frequência de cães com anticorpos anti-B. canis vogeli, anti-E. canis, e anti-Rickettsia spp. foi de 42,6%, 16,2% e 31,7%, respectivamente. Anticorpos anti-B. canis vogeli foram detectados em 59,6% dos cães urbanos, e em 29,1% dos cães rurais (P < 0.05). Para E. canis, a soroprevalência foi parecida entre os cães urbanos (15,7%) e rurais (16,6%). Para Rickettsia spp., cães rurais apresentaram prevalência (P < 0.05) significativamente maior (40,3%) do que os cães urbanos (21,1%). Esse primeiro estudo sobre agentes transmitidos por carrapatos entre cães da Amazônia oriental brasileira indica que estes animais estão expostos a vários agentes. Estes incluem Babesia principalmente na área urbana, Riquétsias do grupo da Febre Maculosa principalmente nas áreas rurais, e Erliquia em cães de ambas as áreas, rural e urbana. Abstract in english Canine ehrlichiosis and babesiosis are the most prevalent tick-borne diseases in Brazilian dogs. Few studies have focused attention in surveying tick-borne diseases in the Brazilian Amazon region. A total of 129 blood samples were collected from dogs living in the Brazilian eastern Amazon. Seventy-two samples from dogs from rural areas of 19 municipalities and 57 samples from urban stray dogs from Santarém municipality were collected. Serum samples were submitted to (more) Indirect Immunofluorescence Assay (IFA) with antigens of Babesia canis vogeli, Ehrlichia canis, and six Rickettsia species. The frequency of dogs containing anti-B. canis vogeli, anti-E. canis, and anti-Rickettsia spp. antibodies was 42.6%, 16.2%, and 31.7%, respectively. Anti-B. canis vogeli antibodies were detected in 59.6% of the urban dogs, and in 29.1% of the rural dogs (P < 0.05). For E. canis, seroprevalence was similar among urban (15.7%) and rural (16.6%) dogs. For Rickettsia spp., rural dogs presented significantly higher (P < 0.05) prevalence (40.3%) than urban animals (21.1%). This first study on tick-borne pathogens in dogs from the Brazilian eastern Amazon indicates that dogs are exposed to several agents, such as Babesia organisms, mostly in the urban area; Spotted Fever group Rickettsia organisms, mostly in the rural area; and Ehrlichia organisms, in dogs from both areas studied.

Spolidorio, Mariana Granziera; Minervino, Antonio Humberto Hamad; Valadas, Samantha Yuri Oshiro Branco; Soares, Herbert Sousa; Neves, Kedson Alessandri Lobo; Labruna, Marcelo Bahia; Ribeiro, Múcio Flavio Barbosa; Gennari, Solange Maria

2013-06-01

313

Antibodies to Rickettsia rickettsii, Rickettsia typhi, Coxiella burnetii, Bartonella henselae, Bartonella quintana, and Ehrlichia chaffeensis among healthy population in Minas Gerais, Brazil  

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Full Text Available Rickettsial diseases except those belonging to spotted fever group rickettsioses are poorly studied in South America particularly in Brazil where few epidemiological reports have been published. We describe a serosurvey for Rickettsia rickettsii, R. typhi, Coxiella burnetii, Bartonella henselae, B. quintana, and Ehrlichia chaffeensis in 437 healthy people from a Brazilian rural community. The serum samples were tested by indirected micro-immunoflourescence technique and a cutoff titer of 1:64 was used. The seroprevalence rates for R. rickettsii, R. typhi, C. burnetii, B. henselae, B. quintana, and E. chaffeensis were respectively 1.6% (7 samples); 1.1% (5 samples); 3.9% (17 samples); 13.7% (60 samples); 12.8% (56 samples), and 10.5% (46 samples). Frequent multiple/cross-reactivity was observed in this study. Age over 40 years old, urban profession, and rural residence were significantly associated with some but not all infections rate. Low seropositivity rates for R. rickettsii, R. typhi, and C. burnetii contrasted with higher rates of seropositivity for B. quintana, B. henselae, and E. chaffeensis. These results show that all tested rickettsial species or antigenically closely related possible exist in this particular region.

Paulo Sérgio Gonçalves da Costa; Marcos Emilio Brigatte; Dirceu Bartolomeu Greco

2005-01-01

314

Effects of the antioxidant alpha-lipoic acid on human umbilical vein endothelial cells infected with Rickettsia rickettsii.  

UK PubMed Central (United Kingdom)

Rickettsia rickettsii infection of endothelial cells is manifested in very distinctive changes in cell morphology, consisting of extensive dilatation of the membranes of the endoplasmic reticulum and outer nuclear envelope and blebbing of the plasma membrane, as seen by transmission electron microscopy (D. J. Silverman, Infect. Immun. 44:545-553, 1984). These changes in cellular architecture are thought to be due to oxidant-mediated cell injury, since their occurrence correlates with dramatic alterations in cellular metabolism, particularly with regard to antioxidant systems. In this study, it was shown that R. rickettsii infection of human umbilical vein endothelial cells resulted in a significant depletion of intracellular reduced glutathione (thiol) content at 72 and 96 h and decreased glutathione peroxidase activity at 72 h postinfection. Infected cells displayed a dramatic increase in the concentration of intracellular peroxides by 72 h. Supplementation of the cell culture medium with 100, 200, or 500 microM alpha-lipoic acid, a metabolic antioxidant, after inoculation with R. rickettsii restored the intracellular levels of thiols and glutathione peroxidase and reduced the intracellular peroxide levels in infected cells. These effects were dose dependent. Treated infected monolayers maintained better viability at 96 h after inoculation with R. rickettsii than did untreated infected cells. Moreover, supplementation of the cell culture medium with 100 microM alpha-lipoic acid for 72 h after infection prevented the occurrence of morphological changes in the infected cells. The presence of 100 or 200 microM alpha-lipoic acid did not influence rickettsial growth in endothelial cells, nor did it affect the ability of R. rickettsii to form lytic plaques in Vero cells. Treatment with 500 microM alpha-lipoic acid decreased by 50% both the number and size of lytic plaques in Vero cells, and it also decreased the recovery of viable rickettsiae from endothelial cells. However, under all treatment conditions, a significant number of rickettsiae could be detected microscopically. Furthermore, the rickettsiae apparently retained their capacity for intracellular movement, since they possessed long polymerized actin tails after 72 and 96 h of treatment regardless of the concentration of alpha-lipoic acid used. Since alpha-lipoic acid does not seem to exhibit direct antirickettsial activity except with long-term exposure at very high concentrations, the mechanism of its protective activity for endothelial cells infected with rickettsiae may involve complex changes in cellular metabolism that only indirectly affect rickettsiae.

Eremeeva ME; Silverman DJ

1998-05-01

315

Solution structure of the cold-shock-like protein from Rickettsia rickettsii.  

UK PubMed Central (United Kingdom)

Rocky Mountain spotted fever is caused by Rickettsia rickettsii infection. R. rickettsii can be transmitted to mammals, including humans, through the bite of an infected hard-bodied tick of the family Ixodidae. Since the R. rickettsii genome contains only one cold-shock-like protein and given the essential nature of cold-shock proteins in other bacteria, the structure of the cold-shock-like protein from R. rickettsii was investigated. With the exception of a short ?-helix found between ?-strands 3 and 4, the solution structure of the R. rickettsii cold-shock-like protein has the typical Greek-key five-stranded ?-barrel structure found in most cold-shock domains. Additionally, the R. rickettsii cold-shock-like protein, with a ?G of unfolding of 18.4?kJ?mol(-1), has a similar stability when compared with other bacterial cold-shock proteins.

Gerarden KP; Fuchs AM; Koch JM; Mueller MM; Graupner DR; O'Rorke JT; Frost CD; Heinen HA; Lackner ER; Schoeller SJ; House PG; Peterson FC; Veldkamp CT

2012-11-01

316

Lateral transfers of insertion sequences between Wolbachia, Cardinium and Rickettsia bacterial endosymbionts.  

UK PubMed Central (United Kingdom)

Various bacteria live exclusively within arthropod cells and collectively act as an important driver of arthropod evolutionary ecology. Whereas rampant intra-generic DNA transfers were recently shown to have a pivotal role in the evolution of the most common of these endosymbionts, Wolbachia, the present study show that inter-generic DNA transfers also commonly take place, constituting a potent source of rapid genomic change. Bioinformatic, molecular and phylogenetic data provide evidence that a selfish genetic element, the insertion sequence ISRpe1, is widespread in the Wolbachia, Cardinium and Rickettsia endosymbionts and experiences recent (and likely ongoing) transfers over long evolutionary distances. Although many ISRpe1 copies were clearly expanding and leading to rapid endosymbiont diversification, degraded copies are also frequently found, constituting an unusual genomic fossil record suggestive of ancient ISRpe1 expansions. Overall, the present data highlight how ecological connections within the arthropod intracellular environment facilitate lateral DNA transfers between distantly related bacterial lineages.

Duron O

2013-10-01

317

Lateral transfers of insertion sequences between Wolbachia, Cardinium and Rickettsia bacterial endosymbionts.  

Science.gov (United States)

Various bacteria live exclusively within arthropod cells and collectively act as an important driver of arthropod evolutionary ecology. Whereas rampant intra-generic DNA transfers were recently shown to have a pivotal role in the evolution of the most common of these endosymbionts, Wolbachia, the present study show that inter-generic DNA transfers also commonly take place, constituting a potent source of rapid genomic change. Bioinformatic, molecular and phylogenetic data provide evidence that a selfish genetic element, the insertion sequence ISRpe1, is widespread in the Wolbachia, Cardinium and Rickettsia endosymbionts and experiences recent (and likely ongoing) transfers over long evolutionary distances. Although many ISRpe1 copies were clearly expanding and leading to rapid endosymbiont diversification, degraded copies are also frequently found, constituting an unusual genomic fossil record suggestive of ancient ISRpe1 expansions. Overall, the present data highlight how ecological connections within the arthropod intracellular environment facilitate lateral DNA transfers between distantly related bacterial lineages. PMID:23759724

Duron, O

2013-06-12

318

Featured Organism: Reductive Evolution in Bacteria: Buchnera sp., Rickettsia Prowazekii and Mycobacterium Leprae  

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Full Text Available Obligate intracellular bacteria commonly have much reduced genome sizes compared to their nearest free-living relatives. One reason for this is reductive evolution: the loss of genes rendered non-essential due to the intracellular habitat. This can occur because of the presence of orthologous genes in the host, combined with the ability of the bacteria to import the protein or metabolite products of the host genes. In this article we take a look at three such bacteria whose genomes have been fully sequenced. Buchnera is an endosymbiont of the pea aphid, Acyrthosiphon pisum, the relationship between these two organisms being so essential that neither can reproduce in the absence of the other. Rickettsia prowazekii is the causative agent of louse-borne typhus in humans and Mycobacterium leprae infection of humans leads to leprosy. Both of these human pathogens have fastidious growth requirements, which has made them very difficult to study.

Jo Wixon

2001-01-01

319

Experimental infection of Rhipicephalus sanguineus ticks with the bacterium Rickettsia rickettsii, using experimentally infected dogs.  

UK PubMed Central (United Kingdom)

We evaluated if Rickettsia rickettsii-experimentally infected dogs could serve as amplifier hosts for hipicephalus sanguineus ticks. In addition, we checked if Rh. sanguineus ticks that acquired Ri. rickettsii from dogs could transmit the bacterium to susceptible hosts (vector competence), and if these ticks could maintain the bacterium by transstadial and transovarial transmissions. Uninfected larvae, nymphs, and adults of Rh. sanguineus were allowed to feed upon three groups of dogs: groups 1 (G1) and 2 (G2) composed of Ri. rickettsii-infected dogs, infected intraperitoneally and via tick bites, respectively, and group 3 composed of uninfected dogs. After larval and nymphal feeding on rickettsemic dogs, 7.1-15.2% and 35.8-37.9% of the molted nymphs and adults, respectively, were shown by polymerase chain reaction (PCR) to be infected by Ri. rickettsii, confirming that both G1 and G2 dogs were efficient sources of rickettsial infection (amplifier host), resulting in transstadial transmission of the agent. These infected nymphs and adults successfully transmitted Ri. rickettsii to guinea pigs, confirming vector competence after acquisition of the infection from rickettsemic dogs. Transovarial transmission of Ri. rickettsii was observed in engorged females that had been infected as nymphs by feeding on both G1 and G2 dogs, but not in engorged females that acquired the infection during adult feeding on these same dogs. In the first case, filial infection rates were generally <50%. No tick exposed to G3 dogs was infected by rickettsiae in this study. No substantial mortality difference was observed between Ri. rickettsii-infected tick groups (G1 and G2) and uninfected tick group (G3). Our results indicate that dogs can be amplifier hosts of Ri. rickettsii for Rh. sanguineus, although only a minority of immature ticks (<45%) should become infected. It appears that Rh. sanguineus, in the absence of horizontal transmission, would not maintain Ri. rickettsii through successive generations, possibly because of low filial infection rates.

Piranda EM; Faccini JL; Pinter A; Pacheco RC; Cançado PH; Labruna MB

2011-01-01

320

Incongruent effects of two isolates of Rickettsia conorii on the survival of Rhipicephalus sanguineus ticks.  

UK PubMed Central (United Kingdom)

Rickettsia conorii, the etiologic agent of Mediterranean spotted fever is widely distributed in Southern Europe, the Middle East, Africa, India and the Caspian region. In the Mediterranean region, the brown dog tick, Rhipicephalus sanguineus, is the recognized vector of R. conorii. To study tick-pathogen relationships and pathogenesis of infection caused in model animals by the bite of an infected tick, we attempted to establish a laboratory colony of Rh. sanguineus persistently infected with R. conorii. Rhipicephalus sanguineus ticks of North American and Mediterranean origin were exposed to R. conorii isolates of African (R. conorii conorii strain Malish) and Mediterranean (R. conorii israelensis strain ISTT) origin. Feeding of ticks upon infected mice and dogs, intra-hemocoel inoculation, and submersion in suspensions of purified rickettsiae were used to introduce the pathogen into uninfected ticks. Feeding success, molting success and the longevity of molted ticks were measured to assess the effects of R. conorii on the survival of Rh. sanguineus. In concordance with previously published results, Rh. sanguineus larvae and nymphs from both North American and Mediterranean colonies exposed to R. conorii conorii Malish experienced high mortality during feeding and molting or immediately after. The prevalence of infection in surviving ticks did not exceed 5%. On the other hand, exposure to ISTT strain had lesser effect on tick survival and resulted in 35-66% prevalence of infection. Rh. sanguineus of Mediterranean origin were more susceptible to infection with either strain of R. conorii than those from North America. Previous experimental studies had demonstrated transovarial and transstadial transmission of R. conorii in Rh. sanguineus; however, our data suggest that different strains of R. conorii may employ different means of maintenance in nature. The vertebrate host may be a more important reservoir than previously thought, or co-feeding transmission between different generations of ticks may obviate or lessen the requirement for transovarial maintenance of R. conorii.

Levin ML; Killmaster L; Zemtsova G; Grant D; Mumcuoglu KY; Eremeeva ME; Dasch GA

2009-12-01

 
 
 
 
321

Detection of Rickettsia tamurae DNA in ticks and wild boar (Sus scrofa leucomystax) skins in Shimane Prefecture, Japan.  

UK PubMed Central (United Kingdom)

We used 24 wild boars trapped from December 2009 to January 2010 and a further 65 from July 2010 to August 2010 in Misato Town, Shimane Prefecture, Japan. We collected blood, spleens, skins and ticks from the wild boars, which were examined for rickettsial infections using polymerase chain reaction (PCR) primers for the genes rickettsial 17-kDa antigen and citrate synthase (gltA). We amplified Rickettsia tamurae AT-1 DNA from the tick Amblyomma testudinarium and from wild boar skins where ticks attached. Antibodies against spotted fever group Rickettsia were detected in wild boar sera using immunofluorescence, whereas blood and spleen samples contained no rickettsial DNA. This study suggests that wild boars have a role as an amplifier and a transporter of A. testudinarium, which harbor R. tamurae. One case of R. tamurae infection in humans was reported in Shimane Prefecture. Therefore, R. tamurae infections in humans might increase, if wild boar populations and their habitats expand.

Motoi Y; Asano M; Inokuma H; Ando S; Kawabata H; Takano A; Suzuki M

2013-01-01

322

A Rickettsia parkeri-like agent infecting Amblyomma calcaratum nymphs from wild birds in Mato Grosso do Sul, Brazil.  

UK PubMed Central (United Kingdom)

In total, 142 birds, mostly passerines, belonging to 42 species were examined for the presence of ticks in 3 locations in Mato Grosso do Sul Brazil during 2006. Seven birds (5%) were infested with 4 nymphs of Amblyomma calcaratum (Ramphocelus carbo, 3 infested/12 examined) and 5 larvae of Amblyomma sp. (Furnarius rufus, 2/5; Turdus leucomelas, 1/6; and Paroaria capitata, 1/8). All 4 nymphs of A. calcaratum tested by polymerase chain reaction targeting rickettsial genes gltA and ompA and by amplicon sequencing were found to be infected with a Rickettsia sp. strain NOD, a Rickettsia parkeri-like agent. A. calcaratum infected with a rickettsial bacterium was found for the first time.

Ogrzewalska M; Martins T; Capek M; Literak I; Labruna MB

2013-02-01

323

Atypical fulminant Rickettsia rickettsii infection (Brazilian spotted fever) presenting as septic shock and Adult Respiratory Distress Syndrome  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Brazilian spotted fever, caused by Rickettsia rickettsii, has been increasingly reported in Brazil especially in the southeastern states. The severe and fulminant forms of the disease are not unusual but most of the reported fatal cases have shown some typical clinical clue, which leads the attending physician to a correct diagnosis. We report a probable case of atypical fulminant Brazilian spotted fever that presented full-blown septic shock associated with Adult Respira (more) tory Distress Syndrome (ARDS) and delayed uncharacteristic rash with an over four-fold increase in reciprocal IgM, but not IgG titer against Rickettsia rickettsii. Brazilian practitioners should be aware of the possibility of Brazilian spotted fever as a cause of fulminant primary sepsis with ARDS; improved laboratory methods are necessary for the rapid diagnosis of such cases.

Costa, Paulo Sérgio Gonçalves da; Brigatte, Marcos Emilio; Almeida, Edmilton Pereira de; Valle, Lena Márcia de Carvalho

2002-04-01

324

Characterization of rickettsia rickettsii in a case of Fatal Brazilian spotted fever in the city of Rio de Janeiro, Brazil  

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Full Text Available A lethal case of Brazilian spotted fever (BSF) is presented. Clinical features were initially of gastrointestinal involvement and evolved with progression to septic shock, meningoencephalitis and death on the 6th day of illness. Indirect immunofluorescence assay (IFA) for spotted fever group rickettsia (SFGR) was non-reactive. Diagnosis was confirmed by the polymerase chain reaction (PCR) and the nucleotide sequencing of a fragment of the ompA gene showed 100% homology to Rickettsia rickettsii. BSF has not been reported in the city of Rio de Janeiro in the last three decades, and the present description should alert the clinicians to its presence in urban Rio de Janeiro, and to the differential diagnosis with dengue fever, gastroenteritis, leptospirosis and bacterial septic shock, among others.

Cristiane Lamas; Alexsandra Favacho; Tatiana Rozental; Márcio N. Bóia; Andrei H. Kirsten; Alexandro Guterres; Jairo Barreira; Elba Regina S. de Lemos

2008-01-01

325

Characterization of rickettsia rickettsii in a case of Fatal Brazilian spotted fever in the city of Rio de Janeiro, Brazil  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english A lethal case of Brazilian spotted fever (BSF) is presented. Clinical features were initially of gastrointestinal involvement and evolved with progression to septic shock, meningoencephalitis and death on the 6th day of illness. Indirect immunofluorescence assay (IFA) for spotted fever group rickettsia (SFGR) was non-reactive. Diagnosis was confirmed by the polymerase chain reaction (PCR) and the nucleotide sequencing of a fragment of the ompA gene showed 100% homology to (more) Rickettsia rickettsii. BSF has not been reported in the city of Rio de Janeiro in the last three decades, and the present description should alert the clinicians to its presence in urban Rio de Janeiro, and to the differential diagnosis with dengue fever, gastroenteritis, leptospirosis and bacterial septic shock, among others.

Lamas, Cristiane; Favacho, Alexsandra; Rozental, Tatiana; Bóia, Márcio N.; Kirsten, Andrei H.; Guterres, Alexandro; Barreira, Jairo; Lemos, Elba Regina S. de

2008-04-01

326

Análisis de las recidivas locorregionales por cáncer de mama Analysis of locoregional relapses from breast cancer  

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Full Text Available Introducción: la recidiva locorregional, luego de una intervención quirúrgica por cáncer de mama, es una gran preocupación para el paciente y una frustración para el cirujano actuante. Objetivos: realizar un estudio descriptivo de las variables asociadas a la recurrencia tumoral, en 949 pacientes operadas. Métodos: se confeccionó una base de datos con las pacientes operadas desde 2005 hasta 2010, se identificaron las variables y análisis univariables y multivariables para determinar si existió asociación estadística. Resultados: se apreció que la incidencia fue de 4,4 %. La intervención quirúrgica previa más frecuente fue la mastectomía radical modificada en 52,4 %, y 26,2 % de los casos que tenían metástasis ganglionares axilares en ese momento. El tipo histológico más frecuente fue el carcinoma ductal infiltrante, de alto grado de malignidad. La infiltración vascular y linfática estuvo presente en 42,8 %. El tratamiento definitivo más empleado fue la exéresis de la recidiva más radioterapia. El análisis multivariables solo asoció la metástasis ganglionar con la reaparición de la enfermedad. Conclusiones: la metástasis ganglionar axilar sigue siendo un factor de mal pronóstico en el seguimiento extenso de la paciente.Introduction: locoregional relapses after a breast cancer surgery is a big concern for the patient and a frustration to the performing surgeon. Objectives: to perform a descriptive study of the tumor recurrence-associated variables in 949 surgical patients. Methods: a database containing the data from operated patients in the period of 2005 through 2010 was made; the variables were identified and the univariate and multivariate analyses allowed determining the probable statistical association. Results: at was observed that the incidence of locoregional recurrence was 4.4 %. The most common previous surgery was modified radical mastectomy in 52.4 % and 26.2 % of cases with axillary ganglionic metastasis at that time. The most frequent histological type was highly malignant infiltrating bile duct carcinoma. The vascular and lymphatic infiltration occurred in 42.8 % of patients. The most used treatment was removal of recurrence plus radiotherapy. The multivariate analysis was associated only to ganglionic metastasis with the reappearance of disease. Conclusions: axillary ganglionic metastasis is still a factor indicating bad prognosis in the long follow-up of a patient.

Oscar Alberto Pérez Gutiérrez; Narciso Montejo Viamontes; Loys Jorge Lázaro; Rafael Castro Cruz; Amauris Estrada González

2012-01-01

327

Serological prevalence study of exposure of cats and dogs in Launceston, Tasmania, Australia to spotted fever group rickettsiae.  

UK PubMed Central (United Kingdom)

A sero-epidemiological study of cats and dogs in the Launceston area of Tasmania, Australia was undertaken to determine the prevalence of antibodies to spotted fever group (SFG) rickettsiae. Results showed that 59% of cats and 57% of dogs were positive for antibodies, but there was no correlation between the animal's health and seropositivity at the time of testing, suggesting that rickettsial exposure is unrelated to ill-health in these two species of domestic animals.

Izzard L; Cox E; Stenos J; Waterston M; Fenwick S; Graves S

2010-01-01

328

Study on tick-borne rickettsiae in eastern Poland. II. Serological response of the occupationally exposed populations.  

UK PubMed Central (United Kingdom)

A group of 150 persons living in the Lublin province of eastern Poland and occupationally exposed to tick bite were examined by the immunoenzymatic ELISA test for the presence of antibodies against tick-borne Spotted Fever Group (SFG) rickettsiae. The group consisted of 75 forestry workers employed in 3 forest inspectorates and 75 agricultural workers living in 2 villages. As a control group, 43 urban dwellers living in the city of Lublin and not occupationally exposed to tick bite were examined. Among 150 persons occupationally exposed to tick bite, the presence of antibodies against SFG rickettsiae was found in 54 (36.0% of the total). In the control group, the frequency of positive findings was only 4.7%, being significantly smaller compared to the exposed group (p=0.0001). Within the exposed group, the percentage of positive results in forestry workers (50.7%) was greater than in agricultural workers (21.3%); the difference was statistically significant (p=0.0002). Also within this group, the frequency of positive findings in males(46.5%) was significantly greater than in females (21.9%) (p=0.0029). In the exposed group, the positive results tended to increase with the age of the examined persons. However, a significant relationship between age and positive findings was found only in forestry workers (?(2) =14.207, p=0.00264), but not in agricultural workers and total exposed workers. The frequencies of positive results in forestry workers varied significantly depending on place of work (?(2) =11.271, p=0.00357). Similarly, the difference between the positive reactions in agricultural workers living in 2 villages proved to be significant (34.2% vs. 8.1%; p=0.0074). The obtained results indicate that people occupationally exposed to tick bite and living in the area of eastern Poland where over half of Dermacentor reticulatus ticks harbour SFG rickettsiae, are under significantly increased risk of infection with these rickettsiae.

Zaj?c V; Wójcik-Fatla A; Cisak E; Sroka J; Sawczyn A; Dutkiewicz J

2013-01-01

329

Molecular detection of hemoprotozoa and Rickettsia species in arthropods collected from wild animals in the Burgos Province, Spain.  

Science.gov (United States)

Limited information on the presence of bacterial and hematozoan infections in parasitic arthropods from Spain is available. In an attempt to address this issue, the prevalence of Theileria, Babesia, Hepatozoon, and Rickettsia species was investigated by polymerase chain reaction plus sequencing. In a survey for zoonotic pathogens in ectoparasites, 42 wild animals (which included rodents, carnivores, Sciuridae, and Cervidae) were captured in Burgos (Spain). A total of 256 arthropods (including 107 ticks, 76 fleas, and 73 mites) were collected from these mammals. Molecular diagnostic results showed that (i) Rickettsia felis was found in fleas (two Ctenocephalides felis), (ii) Hepatozoon sp. infected some fleas (two Ctenophtalmus sp. and a DNA pool of Ceratophyllus sciurorum) and Acari (one Neotrombicula sp.), and (iii) Theileria annae was found in Ixodes ricinus and I. hexagonus (each a single infected specimen). All microorganisms and parasites were genetically identical to pathogens already described in Spain or elsewhere. Infected arthropods were recovered from beech marten, bank vole, squirrel, wood mouse, and red fox. Our findings emphasize the potential risk for transmission of rickettsias to humans (namely, R. felis) in Burgos, since C. felis is capable to seek out humans for feeding. No hemoprotozoa with proven significance as human pathogens were found in the survey. However, finding T. annae in ticks recovered from wild canids suggests possible links of sylvatic and domestic cycles for some Piroplasmida. PMID:20055580

Lledó, Lourdes; Giménez-Pardo, Consuelo; Domínguez-Peñafiel, Gerardo; Sousa, Rita; Gegúndez, Maria Isabep; Casado, Nieves; Criado, Angel

2010-01-07

330

Rickettsia parkeri: a Rickettsial pathogen transmitted by ticks in endemic areas for spotted fever rickettsiosis in southern Uruguay.  

UK PubMed Central (United Kingdom)

At first Rickettsia conorii was implicated as the causative agent of spotted fever in Uruguay diagnosed by serological assays. Later Rickettsia parkeri was detected in human-biting Amblyomma triste ticks using molecular tests. The natural vector of R. conorii, Rhipicephalus sanguineus, has not been studied for the presence of rickettsial organisms in Uruguay. To address this question, 180 R. sanguineus from dogs and 245 A. triste from vegetation (flagging) collected in three endemic localities were screened for spotted fever group (SFG) rickettsiosis in southern Uruguay. Tick extracted DNA pools were subjected to PCR using primers which amplify a fragment of the rickettsial gltA gene. Positive tick DNA pools with these primers were subjected to a second PCR round with primers targeting a fragment of the ompA gene, which is only present in SFG rickettsiae. No rickettsial DNA was detected in R. sanguineus. However, DNA pools of A. triste were found to be positive for a rickettsial organism in two of the three localities, with prevalences of 11.8% to 37.5% positive pools. DNA sequences generated from these PCR-positive ticks corresponded to R. parkeri. These findings, joint with the aggressiveness shown by A. triste towards humans, support previous data on the involvement of A. triste as vector of human infections caused by R. parkeri in Uruguay.

Venzal JM; Estrada-Peña A; Portillo A; Mangold AJ; Castro O; De Souza CG; Félix ML; Pérez-Martínez L; Santibánez S; Oteo JA

2012-05-01

331

First molecular evidence of Anaplasma ovis and Rickettsia spp. in keds (Diptera: Hippoboscidae) of sheep and wild ruminants.  

Science.gov (United States)

To evaluate the presence of rickettsial agents in hippoboscid flies with molecular methods, 81 sheep keds (Melophagus ovinus) were collected from 23 sheep, 144 deer keds (Lipoptena cervi) were caught in the environment, and a further 463 and 59 individuals of the latter species were obtained from fresh carcasses of 29 red deer and 17 roe deer, respectively. DNA was extracted individually or in pools. Anaplasma ovis was demonstrated in all examined sheep keds, and from one pool of free-living deer keds. Rickettsia helvetica or other, unidentified rickettsiae were also present in one pool of sheep keds, and in four pools of deer keds from both red deer and roe deer. This is the first account of polymerase chain reaction positivity of hippoboscid flies for A. ovis and rickettsiae. These results raise the possibility that-apart from cattle and roe deer as already reported-sheep and red deer might also play a reservoir role in the epidemiology of rickettsioses. PMID:21923269

Hornok, Sándor; de la Fuente, José; Biró, Nóra; Fernández de Mera, Isabel G; Meli, Marina L; Elek, Vilmos; Gönczi, Eniko; Meili, Theres; Tánczos, Balázs; Farkas, Róbert; Lutz, Hans; Hofmann-Lehmann, Regina

2011-09-16

332

A new Rickettsia species found in fleas collected from human dwellings and from domestic cats and dogs in Senegal.  

UK PubMed Central (United Kingdom)

The insects of the order Siphonaptera, commonly named fleas, are vectors of pathogens around the world. Our previous studies showed that 4.4% of acute febrile diseases in the Sine-Saloum region of Senegal were due to Rickettsia felis. The aim of this study was to explain the high prevalence of R. felis infections in two rural Senegalese populations by an entomological, systematic monitoring protocol. A total of 232 fleas from three species (Ctenocephalides felis, Echidnophaga gallinacea, and Synosternus pallidus) were collected by candle trapping and manually from pets in the villages of Dielmo and Ndiop during the year 2010. The fleas were then tested for the presence of Bartonella and Rickettsia species. No fleas were found to be positive for any Bartonella species or R. felis. Surprisingly, we found that 91.4% of S. pallidus were infected by a new Rickettsia species, which, based on sequence analysis of gltA, ompB, and two fragments of rpoB, was found to be closely related to R. felis. The results from this study did not explain the high incidence of R. felis infections in these Senegalese populations.

Roucher C; Mediannikov O; Diatta G; Trape JF; Raoult D

2012-05-01

333

A survey for spotted fever group rickettsiae and ehrlichiae in Amblyomma variegatum from St. Kitts and Nevis.  

UK PubMed Central (United Kingdom)

Eighty-nine Amblyomma variegatum ticks were collected from the islands of St. Kitts and Nevis in the Caribbean and preserved in 70% ethanol or local rum. After being washed in sterile water, their DNA was extracted and analyzed by a polymerase chain reaction (PCR) for DNA of spotted fever group rickettsiae and ehrlichiae. None of the tested ticks was positive in a PCR assay using the primers 16S EHRD and 16S EHRR for the 16S rRNA gene of Ehrlichia spp.. Forty-one percent of the A. variegatum (36 of 89 of which 34 [47%] of 72 were adult males, 2 (13%) of 16 were adult females, and 0 (0%) of 1 were nymphs) were positive in a PCR assay using the primer pair 190-70 and 190-701 for the outer membrane protein A (ompA) gene of spotted fever group rickettsiae. All PCR amplification products obtained had 100% sequence homology with Rickettsia africae, the agent of African tick-bite fever.

Kelly PJ; Fournier PE; Parola P; Raoult D

2003-07-01

334

A survey for spotted fever group rickettsiae and ehrlichiae in Amblyomma variegatum from St. Kitts and Nevis.  

Science.gov (United States)

Eighty-nine Amblyomma variegatum ticks were collected from the islands of St. Kitts and Nevis in the Caribbean and preserved in 70% ethanol or local rum. After being washed in sterile water, their DNA was extracted and analyzed by a polymerase chain reaction (PCR) for DNA of spotted fever group rickettsiae and ehrlichiae. None of the tested ticks was positive in a PCR assay using the primers 16S EHRD and 16S EHRR for the 16S rRNA gene of Ehrlichia spp.. Forty-one percent of the A. variegatum (36 of 89 of which 34 [47%] of 72 were adult males, 2 (13%) of 16 were adult females, and 0 (0%) of 1 were nymphs) were positive in a PCR assay using the primer pair 190-70 and 190-701 for the outer membrane protein A (ompA) gene of spotted fever group rickettsiae. All PCR amplification products obtained had 100% sequence homology with Rickettsia africae, the agent of African tick-bite fever. PMID:12932098

Kelly, Patrick J; Fournier, Pierre-Edouard; Parola, Philippe; Raoult, Didier

2003-07-01

335

Rickettsia felis (Rickettsiales: Rickettsiaceae) in Ctenocephalides felis felis (Siphonaptera: Pulicidae) in the State of São Paulo, Brazil Rickettsia felis (Rickettsiales: Rickettsiaceae) em Ctenocephalides felis felis (Siphonaptera: Pulicidae) no estado de São Paulo  

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Full Text Available Samples of 10 and 14 Ctenocephalides felis felis fleas were collected on dogs from Pedreira and Mogi das Cruzes municipalities, respectively, in the State of São Paulo, Brazil, for detection of Rickettsia spp. Individual fleas were submitted to Polymerase Chain Reaction targeting the 17-kDa and the 190-kDa (OmpA) genes of Rickettsiae. This later gene is specific for spotted fever group. Nine fleas from Pedreira (90%) and four fleas from Mogi das Cruzes (28%) were positive for the 17-kDa gene, and eight fleas from Pedreira (80%) and four from Mogi das Cruzes (28%) were positive for 190-kDa gene. The nucleotide sequence of the 190-kDa products of one flea from Pedreira and one flea from Mogi das Cruzes were 100% identical to each other, and when compared to the GenBank Data, they were 100% identical to the 190-kDa sequence of R. felis. This was the first report of its occurrence in the State of São Paulo.Amostras de 10 e 14 pulgas Ctenocephalides felis felis foram coletadas de cães nos municípios de Pedreira e Mogi das Cruzes, respectivamente, no estado de São Paulo, para pesquisa de Rickettsia spp. As pulgas foram individualmente submetidas à reação em cadeia pela polimerase, tendo como alvo os genes 17-kDa e 190-kDa (OmpA) de Rickettsia, sendo esse último específico para o GFM. Nove pulgas de Pedreira (90%) e quatro pulgas de Mogi das Cruzes (28%) foram positivas para o gene 17-kDa, e oito pulgas de Pedreira (80%) e quatro de Mogi das Cruzes (28%) foram positivas para o gene 190-kDa. As seqüências de nucleotídeos do gene 190-kDa de uma pulga de Pedreira e de uma pulga de Mogi das Cruzes foram 100% idênticas; quando comparadas com dados existentes no GenBank, foram 100% idênticas com a seqüência parcial do gene 190-kDa de Rickettsia felis. Esse foi o primeiro relato de sua ocorrência no estado de São Paulo.

M.C. Horta; A. Pinter; A. Cortez; R.M. Soares; S.M. Gennari; T.T.S. Schumaker; M.B. Labruna

2005-01-01

336

Spotted fever group Rickettsia in small rodents from areas of low endemicity for Brazilian spotted fever in the eastern region of Minas Gerais State, Brazil.  

UK PubMed Central (United Kingdom)

We investigated the humoral immune response against different species of Rickettsia in serum samples from small rodents collected in two areas of a silent focus for Brazilian spotted fever in the eastern region of Minas Gerais State, Brazil. Sera samples were analyzed by indirect immunofluorescence assay using antigens from Rickettsia species of the spotted fever, ancestral, and transition groups. Titers ? 1:64 were considered positive. In Santa Cruz do Escalvado, 94% (30 of 32) of the samples collected from Rattus rattus, 22% (5 of 23) from Nectomys squamipes, and 80% (4 of 5) from Akodon sp., reacted by indirect immunofluorescence assay with Rickettsia antigens of the spotted fever group. In the municipality of Pingo D'Água, 84% (26 of 31) of the samples collected from R. rattus, 86% (6 of 7) of the samples from Oryzomys subflavus, 86% (6 of 7) from N. squamipes, and 100% (1 of 1) from Bolomys sp. contained antibodies that reacted with rickettsial antigens of the spotted fever group. These results demonstrated the previous exposure of small rodents to spotted fever group Rickettsia, suggesting the participation of these animals in the natural history of these rickettsiae in this region.

Milagres BS; Padilha AF; Montandon CE; Freitas RN; Pacheco R; Walker DH; Labruna MB; Mafra CL; Galvão MA

2013-05-01

337

Study of infection by Rickettsiae of the spotted fever group in humans and ticks in an urban park located in the City of Londrina, State of Parana, Brazil.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Spotted fevers are emerging zoonoses caused by Rickettsia species in the spotted fever group (SFG). Rickettsia rickettsii is the main etiologic agent of Brazilian spotted fever (BSF)and it is transmitted by Amblyomma spp. ticks. METHODS: The study aimed to investigate SFG rickettsiae in the Arthur Thomas Municipal Park in Londrina, PR, by collecting free-living ticks and ticks from capybaras and blood samples from personnel working in these areas. Samples from A. dubitatum and A. cajennense were submitted for PCR in pools to analyze the Rickettsia spp. gltA (citrate synthase gene). RESULTS: All the pools analyzed were negative. Human sera were tested by indirect immunofluorescence assay with R. rickettsii and R. parkeri as antigens.Among the 34 sera analyzed, seven (20.6%) were reactive for R. rickettsii: four of these had endpoint titers equal to 64, 2 titers were 128 and 1 titer was 256. None of the samples were reactive for R. parkeri. An epidemiological questionnaire was applied to the park staff, but no statistically significant associations were identified. CONCLUSIONS: The serological studies suggest the presence of Rickettsiae related to SFG that could be infecting the human population studied; however, analysis of the ticks collected was unable to determine which species maybe involved in transmission to humans.

Toledo RS; Tamekuni K; de Freitas Silva Filho M; Haydu VB; Pacheco RC; Labruna MB; Dumler JS; Vidotto O

2011-05-01

338

Spotted fever group Rickettsia in small rodents from areas of low endemicity for Brazilian spotted fever in the eastern region of Minas Gerais State, Brazil.  

Science.gov (United States)

We investigated the humoral immune response against different species of Rickettsia in serum samples from small rodents collected in two areas of a silent focus for Brazilian spotted fever in the eastern region of Minas Gerais State, Brazil. Sera samples were analyzed by indirect immunofluorescence assay using antigens from Rickettsia species of the spotted fever, ancestral, and transition groups. Titers ? 1:64 were considered positive. In Santa Cruz do Escalvado, 94% (30 of 32) of the samples collected from Rattus rattus, 22% (5 of 23) from Nectomys squamipes, and 80% (4 of 5) from Akodon sp., reacted by indirect immunofluorescence assay with Rickettsia antigens of the spotted fever group. In the municipality of Pingo D'Água, 84% (26 of 31) of the samples collected from R. rattus, 86% (6 of 7) of the samples from Oryzomys subflavus, 86% (6 of 7) from N. squamipes, and 100% (1 of 1) from Bolomys sp. contained antibodies that reacted with rickettsial antigens of the spotted fever group. These results demonstrated the previous exposure of small rodents to spotted fever group Rickettsia, suggesting the participation of these animals in the natural history of these rickettsiae in this region. PMID:23509125

Milagres, Bruno S; Padilha, Amanda F; Montandon, Carlos E; Freitas, Renata N; Pacheco, Richard; Walker, David H; Labruna, Marcelo B; Mafra, Cláudio L; Galvão, Márcio A M

2013-03-18

339

In vitro isolation from Amblyomma ovale (Acari: Ixodidae) and ecological aspects of the Atlantic rainforest Rickettsia, the causative agent of a novel spotted fever rickettsiosis in Brazil.  

Science.gov (United States)

Recently, a novel human rickettsiosis, namely Atlantic rainforest spotted fever, was described in Brazil. We herein report results of a survey led around the index case in an Atlantic rainforest reserve in Peruibe municipality, southeastern Brazil. A Rickettsia parkeri-like agent (Rickettsia sp. Atlantic rainforest genotype) and Ricketsia bellii were isolated from adult Amblyomma ovale ticks collected from dogs. Molecular evidence of infection with strain Atlantic rainforest was obtained for 30 (12.9%) of 232 A. ovale adult ticks collected from dogs. As many as 88.6% of the 35 examined dogs had anti-Rickettsia antibodies, with endpoint titres at their highest to R. parkeri. High correlation among antibody titres in dogs, A. ovale infestations, and access to rainforest was observed. Amblyomma ovale subadults were found predominantly on a rodent species (Euryoryzomys russatus). From 17 E. russatus tested, 6 (35.3%) displayed anti-Rickettsia antibodies, with endpoint titres highest to R. parkeri. It is concluded that Atlantic rainforest genotype circulates in this Atlantic rainforest area at relatively high levels. Dogs get infected when bitten by A. ovale ticks in the forest, and carry infected ticks to households. The role of E. russatus as an amplifier host of Rickettsia to A. ovale ticks deserves investigation. PMID:23363571

Szabó, M P J; Nieri-Bastos, F A; Spolidorio, M G; Martins, T F; Barbieri, A M; Labruna, M B

2013-05-01

340

Prevalence of Rickettsia spp., Anaplasma phagocytophilum, and Coxiella burnetii in adult Ixodes ricinus ticks from 29 study areas in central and southern Sweden.  

UK PubMed Central (United Kingdom)

A total of 887 adult Ixodes ricinus ticks (469 females and 418 males) from 29 different localities in Sweden were screened for Rickettsia, Anaplasma, and Coxiella DNA using PCR and then subjected to gene sequencing. Rickettsial DNA was detected in 9.5-9.6% of the ticks. Most of the positive ticks were infected with Rickettsia helvetica. One tick harbored another spotted fever rickettsia, closely related to or identical with R. sibirica not previously found in I. ricinus nor in Sweden. Six of the ticks (0.7%) were infected with an Anaplasma sp., presumably A. phagocytophilum. Coxiella burnetii DNA was not detected in any of the ticks. The detection of R. helvetica and A. phagocytophilum in several of the localities sampled suggests that these potentially human-pathogenic agents are common in Sweden.

Wallménius K; Pettersson JH; Jaenson TG; Nilsson K

2012-04-01

 
 
 
 
341

Effects of infection by Arsenophonus and Rickettsia bacteria on the locomotive ability of the ticks Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis.  

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The goal of this study was to determine the effect of vertically transmitted Arsenophonus and Rickettsia bacteria on locomotive ability of larvae of three eastern North American tick species: Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis. We conducted two different experiments on flat or inclined surfaces to measure tick motility. In each experiment, a moderately heated surface was used and placed at a selected incline. The individual's path across the surface was traced for a period of 2 min, or until the larval tick had moved off the surface. Following the microbial identification of Arsenophonus and Rickettsia, a mixed model analysis of variance (ANOVA) indicated that clutch microbial infection status had a significant effect on tick motility with Rickettsia increasing and Arsenophonus decreasing motility averaged over tick species and inclines. There was also a significant difference in motility among tick species and a highly significant effect of the Species*Incline interaction where Dermacentor had higher motility than Ixodes on the flat surface.

Kagemann J; Clay K

2013-01-01

342

Molecular evidence of Ehrlichia canis and Rickettsia massiliae in ixodid ticks of carnivores from South Hungary.  

UK PubMed Central (United Kingdom)

To monitor the emergence of thermophilic, Mediterranean ixodid tick species and tick-borne pathogens in southern Hungary, 348 ticks were collected from shepherd dogs, red foxes and golden jackals during the summer of 2011. Golden jackals shared tick species with both the dog and the red fox in the region. Dermacentor nymphs were collected exclusively from dogs, and the sequence identification of these ticks indicated that dogs are preferred hosts of both D. reticulatus and D. marginatus nymphs, unlike previously reported. Subadults of three ixodid species were selected for reverse line blot hybridisation (RLB) analysis to screen their vector potential for 40 pathogens/groups. Results were negative for Anaplasma, Babesia and Theileria spp. Investigation of D. marginatus nymphs revealed the presence of Ehrlichia canis, Rickettsia massiliae and Borrelia afzelii for the first time in this tick species. These findings broaden the range of those tick-borne agents, which are typically transmitted by Rhipicephalus sanguineus, but may also have Dermacentor spp. as potential or alternative vectors. Ehrlichiacanis was also newly detected in Ixodes canisuga larvae from red foxes. In absence of transovarial transmission in ticks this implies that Eurasian red foxes may play a reservoir role in the epidemiology of canine ehrlichiosis.

Hornok S; Fuente J; Horváth G; Fernández de Mera IG; Wijnveld M; Tánczos B; Farkas R; Jongejan F

2013-03-01

343

Canine seroprevalence of Rickettsia conorii infection (Mediterranean spotted fever) in Castilla y Leon (northwest Spain).  

UK PubMed Central (United Kingdom)

A seroepidemiological study was conducted in 308 dogs to determine the presence of antibodies to Rickettsia conorii, using an indirect immunofluorescence assay (IFA). Seven of the provinces of the Castilla y León region (Burgos, León, Palencia, Salamanca, Soria, Valladolid, and Zamora) were covered by the study. Of the 308 dogs analysed, 72 (23.4%) showed significant titers by IFA (1/40 or higher). Seroprevalences were significantly different between provinces of origin of the animals. These were below 30% in almost all the provinces studied, except for Salamanca province, where the percentage of seropositive dogs was much greater (93.3%). Potential risk factors (presence of ticks on the animals, age, sex, use, habitat, and season) relating to the presence of Mediterranean spotted fever, or Boutonneuse fever, were evaluated. Animals used for guard or pastor activities and those living in rural areas (these factors are closely linked), together with those suffering from tick infestation, had significantly higher seroprevalence than the remainder. The frequency of seropositive dogs increased during the summer months, and these coincide with the period of greatest activity by the vector. Sex and age variables were not identified as risk factors.

Delgado S; Cármenes P

1995-10-01

344

Detection and identification of Anaplasma phagocytophilum, Borrelia burgdorferi, and Rickettsia helvetica in Danish Ixodes ricinus ticks.  

Science.gov (United States)

Borreliosis is an endemic infection in Denmark. Recent serosurveys have indicated that human anaplasmosis may be equally common. The aim of this study was to look for Anaplasma phagocytophilum and related pathogens in Ixodes ricinus ticks and estimate their prevalence, compared to Borrelia, using PCR. Ticks were collected from three locations in Denmark: Jutland, Funen, and Bornholm. Ticks from Jutland and Funen were analysed individually, ticks from Bornholm were analysed in pools of 20. A. phagocytophilum was found in ticks from all areas. A. phagocytophilum was found in 23.6% of ticks from Jutland and Funen, while 11% were positive for Borrelia burgdorferi. The Borrelia genotype B. afzelii was most prevalent, followed by B. valaisiana, B. burgdorferi s.s. and B. garinii.A. phagocytophilum was found in 14.5% of nymphs and 40.5% of adult ticks, while Borrelia was found in 13% of nymphs and 8% of adult ticks. The difference in prevalence between Anaplasma and Borrelia in adult ticks supports the idea that their maintenance cycles in nature may be different. Ticks were also infected with Rickettsia helvetica. Our study indicates that A. phagocytophilum prevalence in ticks in Denmark is as high as Borrelia prevalence and that human anaplasmosis may be unrecognized. PMID:17367468

Skarphédinsson, S; Lyholm, B F; Ljungberg, M; Søgaard, P; Kolmos, H J; Nielsen, L P

2007-03-01

345

Detection and identification of Anaplasma phagocytophilum, Borrelia burgdorferi, and Rickettsia helvetica in Danish Ixodes ricinus ticks.  

UK PubMed Central (United Kingdom)

Borreliosis is an endemic infection in Denmark. Recent serosurveys have indicated that human anaplasmosis may be equally common. The aim of this study was to look for Anaplasma phagocytophilum and related pathogens in Ixodes ricinus ticks and estimate their prevalence, compared to Borrelia, using PCR. Ticks were collected from three locations in Denmark: Jutland, Funen, and Bornholm. Ticks from Jutland and Funen were analysed individually, ticks from Bornholm were analysed in pools of 20. A. phagocytophilum was found in ticks from all areas. A. phagocytophilum was found in 23.6% of ticks from Jutland and Funen, while 11% were positive for Borrelia burgdorferi. The Borrelia genotype B. afzelii was most prevalent, followed by B. valaisiana, B. burgdorferi s.s. and B. garinii.A. phagocytophilum was found in 14.5% of nymphs and 40.5% of adult ticks, while Borrelia was found in 13% of nymphs and 8% of adult ticks. The difference in prevalence between Anaplasma and Borrelia in adult ticks supports the idea that their maintenance cycles in nature may be different. Ticks were also infected with Rickettsia helvetica. Our study indicates that A. phagocytophilum prevalence in ticks in Denmark is as high as Borrelia prevalence and that human anaplasmosis may be unrecognized.

Skarphédinsson S; Lyholm BF; Ljungberg M; Søgaard P; Kolmos HJ; Nielsen LP

2007-03-01

346

Molecular evidence of Ehrlichia canis and Rickettsia massiliae in ixodid ticks of carnivores from South Hungary.  

Science.gov (United States)

To monitor the emergence of thermophilic, Mediterranean ixodid tick species and tick-borne pathogens in southern Hungary, 348 ticks were collected from shepherd dogs, red foxes and golden jackals during the summer of 2011. Golden jackals shared tick species with both the dog and the red fox in the region. Dermacentor nymphs were collected exclusively from dogs, and the sequence identification of these ticks indicated that dogs are preferred hosts of both D. reticulatus and D. marginatus nymphs, unlike previously reported. Subadults of three ixodid species were selected for reverse line blot hybridisation (RLB) analysis to screen their vector potential for 40 pathogens/groups. Results were negative for Anaplasma, Babesia and Theileria spp. Investigation of D. marginatus nymphs revealed the presence of Ehrlichia canis, Rickettsia massiliae and Borrelia afzelii for the first time in this tick species. These findings broaden the range of those tick-borne agents, which are typically transmitted by Rhipicephalus sanguineus, but may also have Dermacentor spp. as potential or alternative vectors. Ehrlichiacanis was also newly detected in Ixodes canisuga larvae from red foxes. In absence of transovarial transmission in ticks this implies that Eurasian red foxes may play a reservoir role in the epidemiology of canine ehrlichiosis. PMID:23439290

Hornok, Sándor; Fuente, José; Horváth, Gábor; Fernández de Mera, Isabel G; Wijnveld, Michiel; Tánczos, Balázs; Farkas, Róbert; Jongejan, Frans

2013-03-01

347

Evaluation of the presence of Rickettsia slovaca infection in domestic ruminants in Catalonia, Northeastern Spain.  

Science.gov (United States)

Rickettsia slovaca is the etiological agent of the human disease tick-borne lymphadenopathy (TIBOLA) transmitted by Dermacentor spp. ticks. In our area, Dermacentor marginatus is the most important tick vector; adult ticks feed on mammals, especially ungulates such as wild boars and domestic ruminants. The epidemiology of tick-transmitted diseases describes a wild cycle and a domestic cycle and both are connected by ticks. To identify the role of domestic ruminants in the transmission and maintenance of R. slovaca infection, blood samples from sheep (n=95), goats (n=91), and bullfighting cattle (n=100) were collected during a herd health program, and livestock grazing was selected to ensure tick contact. Samples were analyzed by serology using an indirect immunofluorescent assay (IFA) and molecular techniques (real-time PCR). Seroprevalence was 15.7% in sheep, 20.8% in goats, and 65.0% in bullfighting cattle. On the basis of molecular methods, R. slovaca infection was demonstrated in a goat blood sample with an antibody titer of 1:160. This is the first time that R. slovaca has been identified in a goat blood sample. These results suggest that domestic ruminants are exposed to R. slovaca infection and, because the domestic cycle is close to the human environment, this could increase the risk of transmitting the pathogen to human beings. PMID:23186170

Ortuño, Anna; Pons, Imma; Quesada, Mariela; Lario, Sergio; Anton, Esperança; Gil, Andreu; Castellà, Joaquim; Segura, Ferran

2012-11-27

348

Evaluation of the presence of Rickettsia slovaca infection in domestic ruminants in Catalonia, Northeastern Spain.  

UK PubMed Central (United Kingdom)

Rickettsia slovaca is the etiological agent of the human disease tick-borne lymphadenopathy (TIBOLA) transmitted by Dermacentor spp. ticks. In our area, Dermacentor marginatus is the most important tick vector; adult ticks feed on mammals, especially ungulates such as wild boars and domestic ruminants. The epidemiology of tick-transmitted diseases describes a wild cycle and a domestic cycle and both are connected by ticks. To identify the role of domestic ruminants in the transmission and maintenance of R. slovaca infection, blood samples from sheep (n=95), goats (n=91), and bullfighting cattle (n=100) were collected during a herd health program, and livestock grazing was selected to ensure tick contact. Samples were analyzed by serology using an indirect immunofluorescent assay (IFA) and molecular techniques (real-time PCR). Seroprevalence was 15.7% in sheep, 20.8% in goats, and 65.0% in bullfighting cattle. On the basis of molecular methods, R. slovaca infection was demonstrated in a goat blood sample with an antibody titer of 1:160. This is the first time that R. slovaca has been identified in a goat blood sample. These results suggest that domestic ruminants are exposed to R. slovaca infection and, because the domestic cycle is close to the human environment, this could increase the risk of transmitting the pathogen to human beings.

Ortuño A; Pons I; Quesada M; Lario S; Anton E; Gil A; Castellà J; Segura F

2012-12-01

349

Comparative evaluation of a commercial enzyme immunoassay for the detection of human antibody to Rickettsia typhi.  

UK PubMed Central (United Kingdom)

A commercial enzyme immunoassay kit called the Dip-S-Ticks (DS) for the detection of total immunoglobulin (Ig) G and IgM human antibodies to Rickettsia typhi was evaluated. In tests with 340 serum samples from patients with diagnosed cases of rickettsial diseases, patients suffering from other febrile illnesses, and normal subjects, the DS compared favorably with the standard indirect fluorescent-antibody (IFA) test. At IFA cutoff titers of > or = 1.64 and > or = 1:128, the DS showed sensitivities of 88.2 and 91.4% and specificities of 91.8 and 87.7%, respectively. The DS test correlated significantly with both the IFA IgG (r = 0.84, P < 0.0005) and IgM (r = 0.63, P < 0.0005) titers. Only 80% of IgG and 82% of IgM IFA readings determined by two technicians were within one dilution, while the DS was more reliable, with 100% within one dot. The rapidity, reliability, and simplicity of the DS suggest that it is a suitable test for use in clinical laboratories unable to perform the IFA test.

Kelly DJ; Chan CT; Paxton H; Thompson K; Howard R; Dasch GA

1995-05-01

350

Population analyses of Amblyomma maculatum ticks and Rickettsia parkeri using single-strand conformation polymorphism.  

UK PubMed Central (United Kingdom)

Gulf Coast ticks, Amblyomma maculatum, and the zoonotic agents they transmit, Rickettsia parkeri, are expanding into areas in the United States where they were not previously reported, and are emerging threats for public and veterinary health. The dynamics of this tick-pathogen system and implications for disease transmission are still unclear. To assess genetic variation of tick and rickettsial populations, we collected adult A. maculatum from 10 sites in Mississippi, 4 in the northern, one in the central, and 5 in the southern part of the state. PCR amplicons from tick mitochondrial 16S rRNA and rickettsial ompA genes as well as 5 intergenic spacer regions were evaluated for genetic variation using single-strand conformation polymorphism analysis. Frequencies of the 4 tick 16S haplotypes were not significantly different among regions of Mississippi, but within sites there were differences in distribution that can be explained by high migration rates. Phylogenetically, one lineage of tick haplotypes was a species-poor sister group to remaining haplotypes in the species-rich sister group. No genetic variation was identified in any of the 6 selected gene targets of R. parkeri examined in the infected ticks, suggesting high levels of intermixing.

Ferrari FA; Goddard J; Caprio M; Paddock CD; Mixson-Hayden T; Varela-Stokes AS

2013-07-01

351

Distribution of Rickettsia rickettsii in ovary cells of Rhipicephalus sanguineus (Latreille1806) (Acari: Ixodidae)  

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Full Text Available Abstract Background Considering the fact that the dog tick, Rhipicephalus sanguineus, has a great potential to become the vector of Brazilian Spotted Fever (BSF) for humans, the present study aimed to describe the distribution of the bacterium Rickettsia rickettsii, the etiological agent of BSF, in different regions of the ovaries of R. sanguineus using histological techniques. The ovaries were obtained from positive females confirmed by the hemolymph test and fed in the nymph stage on guinea pigs inoculated with R. rickettsii. Results The results showed a general distribution of R. rickettsii in the ovary cells, being found in oocytes in all stages of development (I, II, III, IV and V) most commonly in the periphery of the oocyte and also in the cytoplasm of pedicel cells. Conclusions The histological analysis of the ovaries of R. sanguineus infected females confirmed the presence of the bacterium, indicating that the infection can interfere negatively in the process of reproduction of the ticks, once alterations were detected both in the shape and cell structure of the oocytes which contained bacteria.

da Silva Costa Luís; Nunes Pablo; Soares João; Labruna Marcelo; Camargo-Mathias Maria

2011-01-01

352

Molecular typing of isolates of Rickettsia rickettsii by use of DNA sequencing of variable intergenic regions.  

UK PubMed Central (United Kingdom)

Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, is found throughout the Americas, where it is associated with different animal reservoirs and tick vectors. No molecular typing system currently exists to allow for the robust differentiation of isolates of R. rickettsii. Analysis of eight completed genome sequences of rickettsial species revealed a high degree of sequence conservation within the coding regions of chromosomes in the genus. Intergenic regions between coding sequences should be under less selective pressure to maintain this conservation and thus should exhibit greater nucleotide polymorphisms. Utilizing these polymorphisms, we developed a molecular typing system that allows for the genetic differentiation of isolates of R. rickettsii. This typing system was applied to a collection of 38 different isolates collected from humans, animals, and tick vectors from different geographic locations. Serotypes 364D, from Dermacentor occidentalis ticks, and Hlp, from Haemaphysalis leporispalustris ticks, appear to be distinct genotypes that may not belong to the species R. rickettsii. We were also able to differentiate 36 historical isolates of R. rickettsii into three different phylogenetic clades containing seven different genotypes. This differentiation correlated well, but not perfectly, with the geographic origin and likely tick vectors associated with the isolates. The few apparent typing discrepancies found suggest that the molecular ecology of R. rickettsii needs more investigation.

Karpathy SE; Dasch GA; Eremeeva ME

2007-08-01

353

Rickettsia felis in cat fleas, Ctenocephalides felis parasitizing opossums, San Bernardino County, California.  

UK PubMed Central (United Kingdom)

Los Angeles and Orange Counties are known endemic areas for murine typhus in California; however, no recent reports of flea-borne rickettsioses are known from adjacent San Bernardino County. Sixty-five opossums (Didelphis virginiana) were trapped in the suburban residential and industrial zones of the southwestern part of San Bernardino County in 2007. Sixty out of 65 opossums were infested with fleas, primarily cat fleas, Ctenocephalides felis (Bouché, 1835). The flea minimum infection rate with Rickettsia felis was 13.3% in pooled samples and the prevalence was 23.7% in single fleas, with two gltA genotypes detected. In spite of historic records of murine typhus in this area, no evidence for circulation of R. typhi in fleas was found during the present study. Factors contributing to the absence of R. typhi in these cat fleas in contrast to its presence in cat fleas from Orange and Los Angeles Counties are unknown and need to be investigated further in San Bernardino County.

Abramowicz KF; Wekesa JW; Nwadike CN; Zambrano ML; Karpathy SE; Cecil D; Burns J; Hu R; Eremeeva ME

2012-12-01

354

The lspA gene, encoding the type II signal peptidase of Rickettsia typhi: transcriptional and functional analysis.  

UK PubMed Central (United Kingdom)

Lipoprotein processing by the type II signal peptidase (SPase II) is known to be critical for intracellular growth and virulence for many bacteria, but its role in rickettsiae is unknown. Here, we describe the analysis of lspA, encoding a putative SPase II, an essential component of lipoprotein processing in gram-negative bacteria, from Rickettsia typhi. Alignment of deduced amino acid sequences shows the presence of highly conserved residues and domains that are essential for SPase II activity in lipoprotein processing. The transcription of lspA, lgt (encoding prolipoprotein transferase), and lepB (encoding type I signal peptidase), monitored by real-time quantitative reverse transcription-PCR, reveals a differential expression pattern during various stages of rickettsial intracellular growth. The higher transcriptional level of all three genes at the preinfection time point indicates that only live and metabolically active rickettsiae are capable of infection and inducing host cell phagocytosis. lspA and lgt, which are involved in lipoprotein processing, show similar levels of expression. However, lepB, which is involved in nonlipoprotein secretion, shows a higher level of expression, suggesting that LepB is the major signal peptidase for protein secretion and supporting our in silico prediction that out of 89 secretory proteins, only 14 are lipoproteins. Overexpression of R. typhi lspA in Escherichia coli confers increased globomycin resistance, indicating its function as SPase II. In genetic complementation, recombinant lspA from R. typhi significantly restores the growth of temperature-sensitive E. coli Y815 at the nonpermissive temperature, supporting its biological activity as SPase II in prolipoprotein processing.

Rahman MS; Ceraul SM; Dreher-Lesnick SM; Beier MS; Azad AF

2007-01-01

355

Rickettsiae induce microvascular hyperpermeability via phosphorylation of VE-cadherins: evidence from atomic force microscopy and biochemical studies.  

UK PubMed Central (United Kingdom)

The most prominent pathophysiological effect of spotted fever group (SFG) rickettsial infection of microvascular endothelial cells (ECs) is an enhanced vascular permeability, promoting vasogenic cerebral edema and non-cardiogenic pulmonary edema, which are responsible for most of the morbidity and mortality in severe cases. To date, the cellular and molecular mechanisms by which SFG Rickettsia increase EC permeability are largely unknown. In the present study we used atomic force microscopy (AFM) to study the interactive forces between vascular endothelial (VE)-cadherin and human cerebral microvascular EC infected with R. montanensis, which is genetically similar to R. rickettsii and R. conorii, and displays a similar ability to invade cells, but is non-pathogenic and can be experimentally manipulated under Biosafety Level 2 (BSL2) conditions. We found that infected ECs show a significant decrease in VE-cadherin-EC interactions. In addition, we applied immunofluorescent staining, immunoprecipitation phosphorylation assay, and an in vitro endothelial permeability assay to study the biochemical mechanisms that may participate in the enhanced vascular permeability as an underlying pathologic alteration of SFG rickettsial infection. A major finding is that infection of R. montanensis significantly activated tyrosine phosphorylation of VE-cadherin beginning at 48 hr and reaching a peak at 72 hr p.i. In vitro permeability assay showed an enhanced microvascular permeability at 72 hr p.i. On the other hand, AFM experiments showed a dramatic reduction in VE-cadherin-EC interactive forces at 48 hr p.i. We conclude that upon infection by SFG rickettsiae, phosphorylation of VE-cadherin directly attenuates homophilic protein-protein interactions at the endothelial adherens junctions, and may lead to endothelial paracellular barrier dysfunction causing microvascular hyperpermeability. These new approaches should prove useful in characterizing the antigenically related SFG rickettsiae R. conorii and R. rickettsii in a BSL3 environment. Future studies may lead to the development of new therapeutic strategies to inhibit the VE-cadherin-associated microvascular hyperpermeability in SFG rickettsioses.

Gong B; Ma L; Liu Y; Gong Q; Shelite T; Bouyer D; Boor PJ; Lee YS; Oberhauser A

2012-01-01

356

Diversity of Babesia and Rickettsia Species in Questing Ixodes ricinus: A Longitudinal Study in Urban, Pasture, and Natural Habitats.  

Science.gov (United States)

Abstract In a previous study, our group investigated the Babesia spp. prevalence in questing Ixodes ricinus ticks from nine city parks in South Germany in the years 2009 and 2010. We showed predominant prevalence of B. venatorum (in previous literature also known as Babesia sp. EU1), especially in those parks in a more natural condition and with occurrence of large wild animals, such as roe deer. To obtain longitudinal data and to broaden the knowledge about this pathogen, further investigations were carried out in 2011 and 2012 in four of those city parks. Two additional habitat types were chosen for comparison of prevalence data and species analysis focusing on occurrence of potential reservoir hosts. A total of 10,303 questing I. ricinus were collected in four city parks, a pasture, and a natural area in Bavaria, and a representative number of samples were investigated for prevalence of DNA of Babesia spp. (n=4381) and Rickettsia spp. (n=2186) by PCR. In the natural and pasture area, a significantly higher Babesia spp. prevalence compared to the urban area was detected. The natural area revealed sequences of B. microti, B. venatorum, and B. capreoli. In the pasture and urban habitat, predominantly B. venatorum was found, whereas B. capreoli was less frequent and only one B. microti-infected tick was found. All B. microti sequences were 100% identical to the zoonotic Jena/Germany strain. For Rickettsia spp., the significantly highest prevalence was also detected in the natural and pasture areas, whereas lower prevalence was found in the urban area. Sequence analysis revealed R. helvetica (98%) and R. monacensis (2%). Prevalence rates and occurrence of Babesia spp. and Rickettsia spp. differed in urban, pasture and natural sites, most likely depending on the habitat structure (natural or cultivated) and therefore on the appearance and availability of reservoir hosts like roe deer or small mammals. PMID:23697771

Overzier, Evelyn; Pfister, Kurt; Thiel, Claudia; Herb, Ingrid; Mahling, Monia; Silaghi, Cornelia

2013-05-22

357

Diversity of Babesia and Rickettsia Species in Questing Ixodes ricinus: A Longitudinal Study in Urban, Pasture, and Natural Habitats.  

UK PubMed Central (United Kingdom)

Abstract In a previous study, our group investigated the Babesia spp. prevalence in questing Ixodes ricinus ticks from nine city parks in South Germany in the years 2009 and 2010. We showed predominant prevalence of B. venatorum (in previous literature also known as Babesia sp. EU1), especially in those parks in a more natural condition and with occurrence of large wild animals, such as roe deer. To obtain longitudinal data and to broaden the knowledge about this pathogen, further investigations were carried out in 2011 and 2012 in four of those city parks. Two additional habitat types were chosen for comparison of prevalence data and species analysis focusing on occurrence of potential reservoir hosts. A total of 10,303 questing I. ricinus were collected in four city parks, a pasture, and a natural area in Bavaria, and a representative number of s