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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

1990-10-01

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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 SciELO Brazil | Language: Spanish Abstract in spanish 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 inmunofluores [...] cencia 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. Abstract in english 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 an [...] ti 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.

1990-10-01

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Caso probable de fiebre manchada ( Rickettsia felis) transmitida por pulgas / Probable case of flea-borne spotted fever ( Rickettsia felis )  

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Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Rickettsia felis es el agente etiológico de la fiebre manchada transmitida por pulgas, cuyo principal vector y reservorio es Ctenocephalides felis . Típicamente, la enfermedad se presenta como fiebre aguda asociada a cefalea, astenia, exantema máculo-papular generalizado y, en algunos casos, con esc [...] ara de inoculación. En los últimos años, R. felis ha venido adquiriendo un papel importante en la etiología del síndrome febril agudo, calificándola como una enfermedad emergente y subdiagnosticada. La inmunofluorescencia indirecta es actualmente el método diagnóstico de referencia. Sin embargo, esta técnica presenta limitaciones relacionadas con la reacción cruzada que existe entre las diferentes especies del género Rickettsia . En el presente reporte se describe el caso de un paciente de 16 años con síndrome febril agudo secundario a infección probable por R. felis . Abstract in english Rickettsia felis is the etiologic agent of flea-borne spotted fever, with Ctenocephalides felis as its main vector and reservoir. Typically, the disease presents as acute fever associated with headache, asthenia, generalized maculo-papular rash, and in some cases, an inoculation eschar. In recent ye [...] ars, R. felis has acquired an important role in the etiology of the acute febrile syndrome; it is indeed an emerging infectious disease, albeit underdiagnosed. Indirect immunofluorescence assay (IFA) is currently the reference diagnostic method. However, this technique has limitations related to the cross reactivity among different species of rickettsiae. Herein, we describe a case of a 16 year-old patient with an acute febrile syndrome secondary to probable infection with R. felis.

Álvaro A, Faccini-Martínez; Elkin G, Forero-Becerra; Jesús A, Cortés-Vecino; Luis J, Polo-Teran; Jorge H, Jácome; Jimmy J, Vargas; Gustavo, Valbuena; Marylin, Hidalgo.

2013-09-01

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

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Full Text Available 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.
Materiales 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.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 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.

Marcelo B. Labruna

2007-09-01

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

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Full Text Available SciELO Colombia | Language: Spanish 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. Objetivo [...] s. Este trabajo evaluó la infección por rickettsia en capibaras de diferentes regiones del estado de São Paulo, donde las rickettsiosis nunca han sido reportadas. Materiales 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 i [...] n 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 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.

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

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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

2004-01-01

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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 SciELO Colombia | Language: Spanish 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 Montería, 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 detecti [...] on 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.

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

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 SciELO Brazil | Language: English 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 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 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.

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

2012-06-01

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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 SciELO Brazil | Language: English 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 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 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.

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

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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

2007-12-01

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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 SciELO Brazil | Language: English 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 baç [...] o, 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. 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 colle [...] cted 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.

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

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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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English 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 baç [...] o, 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. 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 colle [...] cted 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.

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

2011-06-01

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Ecoepidemiología de la infección por rickettsias en roedores, ectoparásitos y humanos en el noroeste de Antioquia, Colombia / Ecoepidemiology of rickettsial infection in rodents, ectoparasites and humans in northeastern Antioquia, Colombia  

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Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Introducción. Las rickettsias son bacterias patógenas usualmente transmitidas por ectoparásitos, como garrapatas, piojos o pulgas. En la última década se presentaron tres brotes de rickettsiosis con casos fatales en la región noroccidental de Antioquia y en un municipio limítrofe de Córdoba. Objetiv [...] o. Describir la ecología y la epidemiología de las infecciones por Rickettsia spp. en el Urabá antioqueño. Materiales y métodos. Se obtuvieron muestras de 354 roedores y se recolectaron 839 ectoparásitos de estos en los municipios de Apartadó, Turbo y Necoclí. Asimismo, se obtuvieron 220 sueros humanos. Estas muestras fueron estudiadas por reacción en cadena de la polimerasa (PCR) e inmunofluorescencia indirecta (IFI) para la detección de infección por rickettsias. Resultados. Por IFI se detectaron anticuerpos antirickettsias en 130 (43 %) de los roedores y en 53 (24 %) de los sueros humanos estudiados. Además, se amplificaron secuencias del gen gltA específicas del género Rickettsia en 23 (6,8 %) muestras de hígado de roedores, las cuales mostraron una similitud del 98,7 % con R. prowazekii . Una secuencia de gltA obtenida de larvas de garrapatas del género Amblyomma sp., tuvo una identidad mayor de 99 % con las secuencias de R. tamurae . Conclusión. Estos resultados demuestran la circulación de rickettsias en roedores, ectoparásitos y humanos en los municipios estudiados. Abstract in english Introduction: Rickettsia spp. are tick, flea or lice-borne pathogenic bacterium, usually carried by rodents. In the last decade three outbreaks of rickettsial disease including fatalities, occurred in the provinces of Antioquia and Córdoba in northwestern Colombia. Objective: The purpose of this stu [...] dy was to perform an ecological and epidemiological description of the Rickettsia spp infection in the recently affected region of Colombia. Materials and methods: Samples were obtained from 354 rodents and their parasites captured in the municipalities of Apartadó, Turbo and Necoclí. Likewise, 220 human sera were also collected, for detection of infection by Rickettsia spp. Results: Indirect immunofluorescence assay (IFA) revealed that 130 (43%) of the rodents and 53 (24%) of the humans produced antibodies to Rickettsia spp. Additionally, rickettsial DNA was amplified by PCR from 23 (6.8%) rodent liver samples using primers directed to the genus specific gltA gene. While gltA sequences from rodent samples exhibited a 98.7% similitude with R . prowazekii, a sequence amplified from larvae of Amblyomma sp exhibited identities of >99% similarity with R. tamurae . Conclusion: These results demonstrate the presence of rickettsia in rodents, ectoparasites and humans throughout the municipalities studied.

Juan Carlos, Quintero; Andrés Felipe, Londoño; Francisco J, Díaz; Piedad, Agudelo-Flórez; Margarita, Arboleda; Juan David, Rodas.

2013-09-01

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Tuberculose ganglionar: desafio diagnóstico / Tuberculous lymphadenitis: diagnostic challenge  

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Full Text Available SciELO Portugal | Language: Portuguese Abstract in portuguese A tuberculose ganglionar é a forma extrapulmonar mais comum de infecção por Mycobacterium tuberculosis. Não obstante, o mimetismo que mantém com outras patologias leva, comumente, a falha ou atraso na obtenção do diagnóstico correto. Os autores apresentam o caso clínico de tuberculose ganglionar num [...] a doente de 89 anos de idade, com múltiplas co-morbilidades, internada para esclarecimento de quadro constitucional caracterizado por febre e adenopatias cervicais de evolução indolente. Abstract in english Tuberculous lymphadenitis is the most common form of extrapulmonary Mycobacterium tuberculosis infection. Nevertheless, the mimicry that keeps with other pathologies leads, commonly, to failure or delay in obtaining a correct diagnosis. The authors present the case of tuberculous lymphadenitis in a [...] 89 years old female, with multiple co-morbidities, admitted with constitutional framework characterized by fever and cervical lymphadenopathy.

Miguel, Neno; Cláudia, Rocha; Dora, Sargento; Glória, Silva.

2014-02-01

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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 Paraná, Brazil / Estudo da infecção por Rickettsias do grupo da febre maculosa em humanos e carrapatos de um parque urbano na Cidade de Londrina, Estado do Paraná  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese INTRODUÇÃO: A febre maculosa é uma zoonose emergente causada por espécies de Rickettsia do grupo febre maculosa (GFM). Rickettsia rickettsii é o principal agente etiológico da febre maculosa brasileira (FMB) e é transmitida por Amblyomma spp. MÉTODOS: Com o objetivo de obter informações sobre GFM Ri [...] ckettsiae no Parque Municipal Arthur Thomas em Londrina, PR, carrapatos de vida livre e de capivaras foram coletados, assim como amostras de sangue das pessoas que trabalham no parque. A. dubitatum e A. cajennense foram submetidos à PCR em pools para analises de Rickettsia spp. gltA (citrate synthase gene). RESULTADOS: Todos os pools de carrapatos analizados foram negativos. Soros de humanos foram testados pela imunofluorescência indireta com antigenos de R. rickettsii e R. parkeri. Entre os 34 soros analisados, 7 (20,6%) foram positivos para R. rickettsii. Destes, quatro apresentaram títulos iguais a 64, dois iguais a 128 e um, igual a 256, mas nenhum soro reagiu com R. parkeri. Não houve nenhuma associação, estatisticamente significante, entre as variáveis analisadas no questionário epidemiológico fornecido às pessoas que participaram da pesquisa. CONCLUSÕES: Os estudos sorológicos sugerem a presença de alguma Rickettsiae relacionada ao GFM que poderiam estar infectando a população humana estudada. Entretanto, as análises dos carrapatos foram inconclusivas para determinar qual espécie poderia estar envolvida na transmissão para os humanos. Abstract in english 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 may be involved in transmission to humans.

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

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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 Paraná, Brazil / Estudo da infecção por Rickettsias do grupo da febre maculosa em humanos e carrapatos de um parque urbano na Cidade de Londrina, Estado do Paraná  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese INTRODUÇÃO: A febre maculosa é uma zoonose emergente causada por espécies de Rickettsia do grupo febre maculosa (GFM). Rickettsia rickettsii é o principal agente etiológico da febre maculosa brasileira (FMB) e é transmitida por Amblyomma spp. MÉTODOS: Com o objetivo de obter informações sobre GFM Ri [...] ckettsiae no Parque Municipal Arthur Thomas em Londrina, PR, carrapatos de vida livre e de capivaras foram coletados, assim como amostras de sangue das pessoas que trabalham no parque. A. dubitatum e A. cajennense foram submetidos à PCR em pools para analises de Rickettsia spp. gltA (citrate synthase gene). RESULTADOS: Todos os pools de carrapatos analizados foram negativos. Soros de humanos foram testados pela imunofluorescência indireta com antigenos de R. rickettsii e R. parkeri. Entre os 34 soros analisados, 7 (20,6%) foram positivos para R. rickettsii. Destes, quatro apresentaram títulos iguais a 64, dois iguais a 128 e um, igual a 256, mas nenhum soro reagiu com R. parkeri. Não houve nenhuma associação, estatisticamente significante, entre as variáveis analisadas no questionário epidemiológico fornecido às pessoas que participaram da pesquisa. CONCLUSÕES: Os estudos sorológicos sugerem a presença de alguma Rickettsiae relacionada ao GFM que poderiam estar infectando a população humana estudada. Entretanto, as análises dos carrapatos foram inconclusivas para determinar qual espécie poderia estar envolvida na transmissão para os humanos. Abstract in english 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 may be involved in transmission to humans.

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

2011-06-01

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Identificación de una nueva área de infección por Rickettsias del grupo typhi: estudio de un brote de tifus en Huánuco  

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Full Text Available SciELO Peru | Language: Spanish Abstract in spanish Objetivos: Investigar un brote de síndrome febril en el distrito de Punchao mediante una evaluación clínica, laboratorial y entomológica para conocer los factores asociados a la aparición de dicho brote. Materiales y métodos: Debido al reporte de tres pacientes con cuadro clínico febril asociado a c [...] efalea, mialgias y postración en la semana epidemiológica Nº41 del año 2000, procedentes del distrito de Punchao, Humalíes, Huánuco y ante la información de presentación inusual de pacientes febriles en la última semana en dicho lugar, se decidió investigar la naturaleza y características del brote. Se definió como caso a todo paciente con cuadro febril agudo y uno de estos síntomas: cefalea, mialgias o postración; procediéndose a la búsqueda activa de éstos y a la evaluación de presencia de anticuerpos para rickettsias en suero mediante inmunofluorescencia indirecta (IFI). Se capturaron roedores y se colectaron ectoparásitos en las viviendas (roedores, animales domésticos y humanos), a fin de identificar la presencia de Rickettsias en ellos mediante IFI, aislamiento o PCR. Resultados: No se logró el aislamiento del agente causal. Se evidenció circulación de la Rickettsia sp. (serología positiva) tanto en humanos (en casos y en no casos) como en roedores. Se evidenció mayor presencia de malos hábitos de aseo y condiciones inadecuadas de saneamiento básico en los casos (respecto a los no casos) y una disminución de los casos luego del inicio de las medidas de control. Conclusiones: Las evidencias encontradas permitieron identificar un brote de tifus en Punchao, no pudiéndose determinar la especie involucrada debido a que no se aisló el agente causal. Abstract in english Objectives: To assess an outbreak of febrile syndrome in Punchao district through a clinical, laboratorial and entomological evaluation and to find out the factors associated to the occurrence of such outbreak. Materials and methods: Due to the report of three patients from Punchao, Huamalíes (Huanu [...] co) presenting with fever associated to headache, myalgia and postration, on the 41st epidemiological week 2000; and because of an inusual presentation of feverish patients in the last week in such site; we decided to investigate the nature and characteristics of the outbreak. We define as case every patient with a time of illness less than 15 days with fever and one of these symptoms: headache, myalgias and postration and we started actively to look for these cases and to assess the presence of anti-Rickettsias antibodies in serum using IFI. We captured rodents and collected ectoparasites in houses (in rodents, domestic animals and humans), with the purpose of identifying Rickettsias using IFI, isolation and/or PCR. Results: We could not isolate the causal agent. The circulation of Rickettsia (positive serology) in humans (cases and no cases) and in rodents was confirmed. A greater presence of bad habits of cleanliness and inadequate conditions of basic sanitation in cases (in relation to no cases) and a decrease in the number of cases after the beginning of control measures, was evident. Conclusions: The evidences found allowed the identification of a typhus outbreak in Punchao; however, the determination of the involucrated species was not possible because the causal agent was not isolated.

Rosa, Mostorino E; Elizabeth, Anaya R; Leonardo, Mendoza U; Angel, Rosas A.

2003-03-01

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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 SciELO Brazil | Language: English Abstract in portuguese 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 sanguineu [...] s 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. Abstract in english 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 Ri [...] o 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.

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

2009-02-01

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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

2009-01-01

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Genotyping Rickettsia prowazekii Isolates  

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We developed a typing method that can differentiate 8 strains of Rickettsia prowazekii into 7 genotypes. This method can be used to type and trace the origin of R. prowazekii isolated from samples collected during epidemics after a bioterrorism attack.

Zhu, Yong; Medina-sanchez, Aaron; Bouyer, Donald; Walker, David H.; Yu, Xue-jie

2008-01-01

 
 
 
 
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Tropism and pathogenicity of rickettsiae  

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Full Text Available 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 and typhus group 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 towards 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 nonpathogenic 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 nonpathogenic species of spotted fever group rickettsiae in mammalian cells. The growth of nonpathogenic species is restricted in these cells, which is mediated, at least in part, by autophagy. The superinfection of nonpathogenic rickettsiae-infected cells with pathogenic rickettsiae results in an elevated yield of the nonpathogenic rickettsiae and the growth of the pathogenic rickettsiae. Autophagy is restricted in these cells. These results are discussed in this review.

TsuneoUchiyama

2012-06-01

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Tropism and pathogenicity of rickettsiae.  

Science.gov (United States)

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. PMID:22737150

Uchiyama, Tsuneo

2012-01-01

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Phylogenetic diversity of the Rickettsiae.  

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Small subunit rRNA sequences have been determined for representative strains of six species of the family Rickettsiaceae: Rickettsia rickettsii, Rickettsia prowazekii, Rickettsia typhi, Coxiella burnetii, Ehrlichia risticii, and Wolbachia persica. The relationships among these sequences and those of other eubacteria show that all members of the family Rickettsiaceae belong to the so-called purple bacterial phylum. The three representatives of the genus Rickettsia form a tight monophyletic clu...

Weisburg, W. G.; Dobson, M. E.; Samuel, J. E.; Dasch, G. A.; Mallavia, L. P.; Baca, O.; Mandelco, L.; Sechrest, J. E.; Weiss, E.; Woese, C. R.

1989-01-01

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Seroprevalencia de la infección por Borrelia burgdorgferi y Rickettsia conorii en población humana y canina de la zona básica de salud de San Andrés del Rabanedo (León, España  

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Full Text Available FUNDAMENTOS: Se estudia la seroprevalencia de la infección por Borrelia burgdorferi y Rickettsia conorii en población humana y canina para conocer la situación de ambas en humanos, al mismo tiempo que la significación del perro, como indicador de la circulación de estos agentes entre aquéllos, en la Zona de Salud de San Andrés del Rabanedo, León. MÉTODO: Se realizó un estudio en 98 sueros humanos y 95 caninos (de diversas razas y aptitudes frente a B. burgdorferi (títulos de positividad > a 1/128 y > a 1/64 o superiores, respectivamente y 104 sueros humanos y 84 caninos frente a R. conorii (positividad a título > a 1/64 o superiores en ambas especies mediante inmunofluorescencia indirecta (IFI. RESULTADOS: Se halló positividad a las dos infecciones, tanto en personas como en perros. Frente a B. burgdorferi fue superior en humanos que en perros y frente a R. conorii fue superior en éstos que en humanos. En personas fue del 4,08% frente a B. burgdorferi y 1% frente a R. conorii; en perros fue del 2,10% frente a B. burgdorferi y del 14,28% frente a R. conorii. Los valores más altos se hallaron en los meses de primavera-verano, salvo en el caso de B. burgdorferi en perros. La seroprevalencia fue mayor en perros dedicados al cuidado de ganado (ovino que en los de caza y guarda. CONCLUSIONES: Los porcentajes de seroprevalencia hallados en nuestro trabajo, tanto en seres humanos como en caninos, considerados en el ámbito territorial de una zona geográfica semi-rural de la provincia de León, han sido iguales o inferiores a los reseñados para otras provincias, incluida la totalidad de la de León. En perros se halló mayor seroprevalencia frente a R. conorii que frente a B. burgdorferi, lo que indica que es el agente más extendido en nuestra Provincia, como han señalado otros autores. Los valores hallados en seres humanos frente a B. burgdorferi han sido más altos que en perros; la existencia de reacciones cruzadas con otros microorganismos ha podido influenciar estos resultados. Por ello, consideramos necesario realizar más estudios de prevalencia de estas infecciones para una vigilancia epidemiológica adecuada y control de estas zoonosis, dada su repercusión en salud pública.

Rojo Vázquez Jaime

1997-01-01

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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

2010-12-01

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Genotyping Rickettsia prowazekii isolates.  

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We developed a typing method that can differentiate 8 strains of Rickettsia prowazekii into 7 genotypes. This method can be used to type and trace the origin of R. prowazekii isolated from samples collected during epidemics after a bioterrorism attack. PMID:18680662

Zhu, Yong; Medina-Sanchez, Aaron; Bouyer, Donald; Walker, David H; Yu, Xue-Jie

2008-08-01

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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 SciELO Brazil | Language: English 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 me [...] nsalmente com armadilhas de CO2, em áreas de risco para FMB de Americana, de julho de 2009 a junho de 2010. Duas espécies foram capturadas, 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 m [...] onthly 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 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.

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

2013-09-01

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Factores predictores de metástasis ganglionar en el carcinoma diferenciado de tiroides  

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Full Text Available SciELO Argentina | Language: Spanish 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 operado [...] s por carcinoma diferenciado de tiroides. Lugar de apicación: práctica privada. Diseño: retrospectivo observacional. Pobación: entre enero de 2000 y agosto de 2010, a 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 differentia [...] ted thyroid carcinoma. Setting: prívate practice. Design: retrospective observational. Popuation: between January 2000 and August 2010, 600 patients with 639 tumours (39 bilateral) 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.

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

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Pathogenic rickettsiae as bioterrorism agents.  

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Because of their unique biological characteristics, such as environmental stability, small size, aerosol transmission, persistence in infected hosts, low infectious dose, and high associated morbidity and mortality, Rickettsia prowazekii and Coxiella burnetii have been weaponized. These biological attributes would make the pathogenic rickettsiae desirable bioterrorism agents. However, production of highly purified, virulent, weapon-quality rickettsiae is a daunting task that requires expertise and elaborate, state-of-the art laboratory procedures to retain rickettsial survival and virulence. Another drawback to developing rickettsial pathogens as biological weapons is their lack of direct transmission from host to host and the availability of very effective therapeutic countermeasures against these obligate intracellular bacteria. PMID:17582570

Azad, Abdu F

2007-07-15

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Ecology of rickettsia in South America.  

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Until the year 2000, only three Rickettsia species were known in South America: (i) Rickettsia rickettsii, transmitted by the ticks Amblyomma cajennense, and Amblyomma aureolatum, reported in Colombia, Argentina, and Brazil, where it is the etiological agent of Rocky Mountain spotted fever; (ii) Rickettsia prowazekii, transmitted by body lice and causing epidemic typhus in highland areas, mainly in Peru; (iii) Rickettsia typhi, transmitted by fleas and causing endemic typhus in many countries. During this new century, at least seven other rickettsiae were reported in South America: Rickettsia felis infecting fleas and the tick-associated agents Rickettsia parkeri, Rickettsia massiliae, Candidatus"Rickettsia amblyommii,"Rickettsia bellii, Rickettsia rhipicephali, and Candidatus"Rickettsia andeanae." Among these other rickettsiae, only R. felis, R. parkeri, and R. massiliae are currently recognized as human pathogens. R. rickettsii is a rare agent in nature, infecting rickettsiae being transmitted transovarially through tick generations, low infection rates for R. rickettsii are possibly related to pathogenic effect of R. rickettsii for ticks, as shown for A. aureolatum under laboratory conditions. This scenario implies that R. rickettsii needs amplifier vertebrate hosts for its perpetuation in nature, in order to create new lines of infected ticks (horizontal transmission). In Brazil, capybaras and opossums are the most probable amplifier hosts for R. rickettsii, among A. cajennense ticks, and small rodents for A. aureolatum. PMID:19538276

Labruna, Marcelo B

2009-05-01

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Rickettsia parkeri and Rickettsia montanensis, Kentucky and Tennessee, USA.  

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We found that 14.3% (15/105) of Amblyomma maculatum and 3.3% (10/299) of Dermacentor variabilis ticks collected at 3 high-use military training sites in west-central Kentucky and northern Tennessee, USA, were infected with Rickettsia parkeri and Rickettsia montanensis, respectively. These findings warrant regional increased public health awareness for rickettsial pathogens and disease. PMID:25271771

Pagac, Benedict B; Miller, Melissa K; Mazzei, Meagan C; Nielsen, David H; Jiang, Ju; Richards, Allen L

2014-10-01

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Tuberculosis ganglionar en un adulto joven / Lymph node tuberculosis in a young adult  

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Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se expone el caso clínico de un recluso de 34 años de edad, de procedencia rural, quien fue atendido por especialistas de neumología a causa de cuadro febril crónico, astenia, pérdida de peso, inapetencia y aumento de volumen no doloroso en la región lateral derecha del cuello. Los exámenes compleme [...] ntarios mostraron imágenes de adenomegalias en hilio hepático y epigastrio. La muestra extraída del ganglio cervical para biopsia reveló necrosis caseosa de origen tuberculoso, por lo cual se diagnosticó tuberculosis ganglionar con afectación de cadenas ganglionares superficiales y profundas; enfermedad muy poco frecuente con esas características en el territorio. Abstract in english The case of 34 year-old prisoner is reported, who lived in a rural area and was attended by pulmonologists because of chronic feverishness, asthenia, weight loss, loss of appetite and painless enlargement in the right lateral region of the neck. Complementary tests revealed lymphadenopathies in port [...] a of liver and epigastrium. Cervical node biopsy revealed tuberculous caseous necrosis, thus diagnosing as lymph node tuberculosis with involvement of superficial and deep lymph node chains; an infrequent disease with these characteristics in the territory.

Joaquín, López González; Sahily, Quintero Salcedo; Odalis, García Gómez; Haydée, Marrero Rodríguez; Odalis, López Soria.

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Tuberculosis ganglionar en un adulto joven Lymph node tuberculosis in a young adult  

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Full Text Available Se expone el caso clínico de un recluso de 34 años de edad, de procedencia rural, quien fue atendido por especialistas de neumología a causa de cuadro febril crónico, astenia, pérdida de peso, inapetencia y aumento de volumen no doloroso en la región lateral derecha del cuello. Los exámenes complementarios mostraron imágenes de adenomegalias en hilio hepático y epigastrio. La muestra extraída del ganglio cervical para biopsia reveló necrosis caseosa de origen tuberculoso, por lo cual se diagnosticó tuberculosis ganglionar con afectación de cadenas ganglionares superficiales y profundas; enfermedad muy poco frecuente con esas características en el territorio.The case of 34 year-old prisoner is reported, who lived in a rural area and was attended by pulmonologists because of chronic feverishness, asthenia, weight loss, loss of appetite and painless enlargement in the right lateral region of the neck. Complementary tests revealed lymphadenopathies in porta of liver and epigastrium. Cervical node biopsy revealed tuberculous caseous necrosis, thus diagnosing as lymph node tuberculosis with involvement of superficial and deep lymph node chains; an infrequent disease with these characteristics in the territory.

Joaquín López González

2011-09-01

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Tuberculosis ganglionar en un adulto joven / Lymph node tuberculosis in a young adult  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se expone el caso clínico de un recluso de 34 años de edad, de procedencia rural, quien fue atendido por especialistas de neumología a causa de cuadro febril crónico, astenia, pérdida de peso, inapetencia y aumento de volumen no doloroso en la región lateral derecha del cuello. Los exámenes compleme [...] ntarios mostraron imágenes de adenomegalias en hilio hepático y epigastrio. La muestra extraída del ganglio cervical para biopsia reveló necrosis caseosa de origen tuberculoso, por lo cual se diagnosticó tuberculosis ganglionar con afectación de cadenas ganglionares superficiales y profundas; enfermedad muy poco frecuente con esas características en el territorio. Abstract in english The case of 34 year-old prisoner is reported, who lived in a rural area and was attended by pulmonologists because of chronic feverishness, asthenia, weight loss, loss of appetite and painless enlargement in the right lateral region of the neck. Complementary tests revealed lymphadenopathies in port [...] a of liver and epigastrium. Cervical node biopsy revealed tuberculous caseous necrosis, thus diagnosing as lymph node tuberculosis with involvement of superficial and deep lymph node chains; an infrequent disease with these characteristics in the territory.

Joaquín, López González; Sahily, Quintero Salcedo; Odalis, García Gómez; Haydée, Marrero Rodríguez; Odalis, López Soria.

2011-09-01

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Rickettsia parkeri Rickettsiosis, Argentina.  

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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. PMID:21762568

Romer, Yamila; Seijo, Alfredo C; Crudo, Favio; Nicholson, William L; Varela-Stokes, Andrea; Lash, R Ryan; Paddock, Christopher D

2011-07-01

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Rickettsiae in Gulf Coast Ticks, Arkansas, USA  

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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, Rebecca; Steelman, C. Dayton; Szalanski, Allen L.; Williamson, Phillip C.

2010-01-01

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O estadiamento ganglionar na actualidade / Node staging today  

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Full Text Available SciELO Portugal | Language: Portuguese Abstract in portuguese A necessidade de realizar Esvaziamento Ganglionar Axilar quando o Gânglio Sentinela está metastizado, em doentes com Cancro da Mama, está a ser questionada. A maior parte dos doentes não apresenta metástases adicionais em Gânglios Não Sentinela e, em muito casos, a decisão de realizar tratamentos ad [...] juvantes não necessita da informação adicional fornecida pelo estudo dos gânglios axilares. A publicação recente do ensaio randomizado ACOSOG Z0011veio relançar a discussão sobre a necessidade e a utilidade do Esvaziamento Ganglionar Axilar. Abstract in english The need to perform an Axillary Dissection when the Sentinel Node is metastasized, in Breast Cancer patients, is being questioned. Most part of the patients do not have any additional metastasis in the Non Sentinel Nodes and, in many cases, the decision to perform adjuvant treatments is not dependen [...] t on the axillary nodes analysis. The recent publication of the randomized trial ACOSOG Z0011 launched the discussion on the need and usefulness of the axillary lymph node dissection.

José Luís, Fougo; Fernando, Osório; Susy, Costa; André, Magalhães.

2013-12-01

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O estadiamento ganglionar na actualidade / Node staging today  

Scientific Electronic Library Online (English)

Full Text Available SciELO Portugal | Language: Portuguese Abstract in portuguese A necessidade de realizar Esvaziamento Ganglionar Axilar quando o Gânglio Sentinela está metastizado, em doentes com Cancro da Mama, está a ser questionada. A maior parte dos doentes não apresenta metástases adicionais em Gânglios Não Sentinela e, em muito casos, a decisão de realizar tratamentos ad [...] juvantes não necessita da informação adicional fornecida pelo estudo dos gânglios axilares. A publicação recente do ensaio randomizado ACOSOG Z0011veio relançar a discussão sobre a necessidade e a utilidade do Esvaziamento Ganglionar Axilar. Abstract in english The need to perform an Axillary Dissection when the Sentinel Node is metastasized, in Breast Cancer patients, is being questioned. Most part of the patients do not have any additional metastasis in the Non Sentinel Nodes and, in many cases, the decision to perform adjuvant treatments is not dependen [...] t on the axillary nodes analysis. The recent publication of the randomized trial ACOSOG Z0011 launched the discussion on the need and usefulness of the axillary lymph node dissection.

José Luís, Fougo; Fernando, Osório; Susy, Costa; André, Magalhães.

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Genomic Comparison of Rickettsia honei Strain RBT and Other Rickettsia Species  

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Rickettsia honei strain RBT was isolated from a febrile patient on Flinders Island, Australia, in 1991 and has been demonstrated to be the agent of Flinders Island spotted fever, a disease transmitted to humans by ticks. The comparison of this 1.27-Mb genome with other Rickettsia genomes provides additional insight into the mechanisms of evolution in Rickettsia species. PMID:22815457

Xin, Dong; El Karkouri, Khalid; Robert, Catherine; Raoult, Didier

2012-01-01

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Genomic comparison of Rickettsia honei strain RBT and other Rickettsia Species.  

Science.gov (United States)

Rickettsia honei strain RB(T) was isolated from a febrile patient on Flinders Island, Australia, in 1991 and has been demonstrated to be the agent of Flinders Island spotted fever, a disease transmitted to humans by ticks. The comparison of this 1.27-Mb genome with other Rickettsia genomes provides additional insight into the mechanisms of evolution in Rickettsia species. PMID:22815457

Xin, Dong; El Karkouri, Khalid; Robert, Catherine; Raoult, Didier; Fournier, Pierre-Edouard

2012-08-01

 
 
 
 
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Seroprevalencia de la infección por Borrelia burgdorgferi y Rickettsia conorii en población humana y canina de la zona básica de salud de San Andrés del Rabanedo (León, España) / Seroprevalence of the infection caused by Borrelia burgdorferi and Rickettsia conorii in human and canine population in the basic health area of San Andrés del Rabanedo (León, Spain)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish FUNDAMENTOS: Se estudia la seroprevalencia de la infección por Borrelia burgdorferi y Rickettsia conorii en población humana y canina para conocer la situación de ambas en humanos, al mismo tiempo que la significación del perro, como indicador de la circulación de estos agentes entre aquéllos, en la [...] Zona de Salud de San Andrés del Rabanedo, León. MÉTODO: Se realizó un estudio en 98 sueros humanos y 95 caninos (de diversas razas y aptitudes) frente a B. burgdorferi (títulos de positividad > a 1/128 y > a 1/64 o superiores, respectivamente) y 104 sueros humanos y 84 caninos frente a R. conorii (positividad a título > a 1/64 o superiores en ambas especies) mediante inmunofluorescencia indirecta (IFI). RESULTADOS: Se halló positividad a las dos infecciones, tanto en personas como en perros. Frente a B. burgdorferi fue superior en humanos que en perros y frente a R. conorii fue superior en éstos que en humanos. En personas fue del 4,08% frente a B. burgdorferi y 1% frente a R. conorii; en perros fue del 2,10% frente a B. burgdorferi y del 14,28% frente a R. conorii. Los valores más altos se hallaron en los meses de primavera-verano, salvo en el caso de B. burgdorferi en perros. La seroprevalencia fue mayor en perros dedicados al cuidado de ganado (ovino) que en los de caza y guarda. CONCLUSIONES: Los porcentajes de seroprevalencia hallados en nuestro trabajo, tanto en seres humanos como en caninos, considerados en el ámbito territorial de una zona geográfica semi-rural de la provincia de León, han sido iguales o inferiores a los reseñados para otras provincias, incluida la totalidad de la de León. En perros se halló mayor seroprevalencia frente a R. conorii que frente a B. burgdorferi, lo que indica que es el agente más extendido en nuestra Provincia, como han señalado otros autores. Los valores hallados en seres humanos frente a B. burgdorferi han sido más altos que en perros; la existencia de reacciones cruzadas con otros microorganismos ha podido influenciar estos resultados. Por ello, consideramos necesario realizar más estudios de prevalencia de estas infecciones para una vigilancia epidemiológica adecuada y control de estas zoonosis, dada su repercusión en salud pública. Abstract in english BACKGROUND: Positive results in infections of borrelia burgdorferi and Rickettsia conorii in human and canine population is studied in order to uderstand the situation of both in humans, and at the same time discover the importance of the dog as an indicator of these agents amongst those in the Heal [...] th Area of San Andrés del Rabanedo, León. METHODS: A study was made of 98 human serums and 95 canine serums (dogs of different breeds and capabilities) as regards B. burgdorferi (positive results > at 1/128 and > at 1/64 or above, respectively) and 104 human serums and 84 canine serums as regards R. conorii (postive results at range > at 1/64 or above in both species) by means of indirect Immunofluorescence (IFI). RESULTS: Positivity in both infections was discovered in both humans and dogs. With regard to B. burgdorferi it was higher in humans than in dogs and with regard to R. conorii it was higher in dogs than in humans. In humans it was 4,08% as regards B. burgdorferi and 1% with respect to R. conorii; in dogs it was 2,10% as regards B. burgdorferi and 14,28% regarding R. conorii. The highest values were discovered in the Spring-Summer months except in the case of B. burgdorferi in dogs. Serum prevalence was greater in dogs used to guard other animals (sheep) than those involved in hunting and security. CONCLUSIONS: The percentages of positive results discovered in our work, in humans as well as dogs, estimated in the territorial area of a geographical zone in a semi-rural León province, were equal or inferior to those discovered in other provinces, including ours. In dogs there were larger positive results regarding R. conorii than B. burgdorferi, which indicates that it is the most extended agent within our Province, a

Jaime, Rojo Vázquez.

1997-03-01

42

Seroprevalencia de la infección por Borrelia burgdorgferi y Rickettsia conorii en población humana y canina de la zona básica de salud de San Andrés del Rabanedo (León, España) / Seroprevalence of the infection caused by Borrelia burgdorferi and Rickettsia conorii in human and canine population in the basic health area of San Andrés del Rabanedo (León, Spain)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Spanish Abstract in spanish FUNDAMENTOS: Se estudia la seroprevalencia de la infección por Borrelia burgdorferi y Rickettsia conorii en población humana y canina para conocer la situación de ambas en humanos, al mismo tiempo que la significación del perro, como indicador de la circulación de estos agentes entre aquéllos, en la [...] Zona de Salud de San Andrés del Rabanedo, León. MÉTODO: Se realizó un estudio en 98 sueros humanos y 95 caninos (de diversas razas y aptitudes) frente a B. burgdorferi (títulos de positividad > a 1/128 y > a 1/64 o superiores, respectivamente) y 104 sueros humanos y 84 caninos frente a R. conorii (positividad a título > a 1/64 o superiores en ambas especies) mediante inmunofluorescencia indirecta (IFI). RESULTADOS: Se halló positividad a las dos infecciones, tanto en personas como en perros. Frente a B. burgdorferi fue superior en humanos que en perros y frente a R. conorii fue superior en éstos que en humanos. En personas fue del 4,08% frente a B. burgdorferi y 1% frente a R. conorii; en perros fue del 2,10% frente a B. burgdorferi y del 14,28% frente a R. conorii. Los valores más altos se hallaron en los meses de primavera-verano, salvo en el caso de B. burgdorferi en perros. La seroprevalencia fue mayor en perros dedicados al cuidado de ganado (ovino) que en los de caza y guarda. CONCLUSIONES: Los porcentajes de seroprevalencia hallados en nuestro trabajo, tanto en seres humanos como en caninos, considerados en el ámbito territorial de una zona geográfica semi-rural de la provincia de León, han sido iguales o inferiores a los reseñados para otras provincias, incluida la totalidad de la de León. En perros se halló mayor seroprevalencia frente a R. conorii que frente a B. burgdorferi, lo que indica que es el agente más extendido en nuestra Provincia, como han señalado otros autores. Los valores hallados en seres humanos frente a B. burgdorferi han sido más altos que en perros; la existencia de reacciones cruzadas con otros microorganismos ha podido influenciar estos resultados. Por ello, consideramos necesario realizar más estudios de prevalencia de estas infecciones para una vigilancia epidemiológica adecuada y control de estas zoonosis, dada su repercusión en salud pública. Abstract in english BACKGROUND: Positive results in infections of borrelia burgdorferi and Rickettsia conorii in human and canine population is studied in order to uderstand the situation of both in humans, and at the same time discover the importance of the dog as an indicator of these agents amongst those in the Heal [...] th Area of San Andrés del Rabanedo, León. METHODS: A study was made of 98 human serums and 95 canine serums (dogs of different breeds and capabilities) as regards B. burgdorferi (positive results > at 1/128 and > at 1/64 or above, respectively) and 104 human serums and 84 canine serums as regards R. conorii (postive results at range > at 1/64 or above in both species) by means of indirect Immunofluorescence (IFI). RESULTS: Positivity in both infections was discovered in both humans and dogs. With regard to B. burgdorferi it was higher in humans than in dogs and with regard to R. conorii it was higher in dogs than in humans. In humans it was 4,08% as regards B. burgdorferi and 1% with respect to R. conorii; in dogs it was 2,10% as regards B. burgdorferi and 14,28% regarding R. conorii. The highest values were discovered in the Spring-Summer months except in the case of B. burgdorferi in dogs. Serum prevalence was greater in dogs used to guard other animals (sheep) than those involved in hunting and security. CONCLUSIONS: The percentages of positive results discovered in our work, in humans as well as dogs, estimated in the territorial area of a geographical zone in a semi-rural León province, were equal or inferior to those discovered in other provinces, including ours. In dogs there were larger positive results regarding R. conorii than B. burgdorferi, which indicates that it is the most extended agent within our Pro

Jaime, Rojo Vázquez.

1997-03-01

43

Ganglio postcentinela en melanoma: nuevo método diagnóstico para la detección de metástasis ganglionares pélvicas / Postsentinel lymph node in melanoma: a new diagnostic method for detection of metastatic pelvic lymph nodes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Los ganglios inguinales son el primer sitio de afectación metastásica del melanoma primario de las extremidades inferiores. Cuando se comprueba metástasis ganglionares inguinales no es claro si solamente se debe realizar linfadenectomía inguinal superficial (linfadenectomía ganglionar limitada) o si [...] por el contrario, se debe efectuar linfadenectomía pélvica (cadena ganglionar ilíaca externa y obturador), además de la linfadenectomía inguinal superficial (linfadenectomía ganglionar extendida o combinada). Se propone al ganglio postcentinela como nuevo método diagnóstico capaz de predecir el compromiso ganglionar pélvico y así reducir el número de vaciamientos pélvicos innecesarios. Abstract in english Inguinal nodes are the first site of metastatic location of a primary melanoma of the lower extremities. Once inguinal metastatic lymph nodes are demonstrated, it is still not clear if the best conduct is to perform a superficial inguinal lymphadenectomy (limited lymphadenectomy) or, on the contrary [...] , a pelvic lymphadenectomy (extended or combined inguinal lymphadenectomy). It is proposed the postsentinel node as anew diagnostic method capable of predicting pelvic node involvement and thus reducing the number of unnecessary pelvic dissections.

Eduardo, Torregroza-Diazgranados; Javier Ángel, Aristizábal; Luis Fernando, Viaña; Juan David, Figueroa.

44

Ganglio postcentinela en melanoma: nuevo método diagnóstico para la detección de metástasis ganglionares pélvicas Postsentinel lymph node in melanoma: a new diagnostic method for detection of metastatic pelvic lymph nodes  

Directory of Open Access Journals (Sweden)

Full Text Available Los ganglios inguinales son el primer sitio de afectación metastásica del melanoma primario de las extremidades inferiores. Cuando se comprueba metástasis ganglionares inguinales no es claro si solamente se debe realizar linfadenectomía inguinal superficial (linfadenectomía ganglionar limitada o si por el contrario, se debe efectuar linfadenectomía pélvica (cadena ganglionar ilíaca externa y obturador, además de la linfadenectomía inguinal superficial (linfadenectomía ganglionar extendida o combinada. Se propone al ganglio postcentinela como nuevo método diagnóstico capaz de predecir el compromiso ganglionar pélvico y así reducir el número de vaciamientos pélvicos innecesarios.Inguinal nodes are the first site of metastatic location of a primary melanoma of the lower extremities. Once inguinal metastatic lymph nodes are demonstrated, it is still not clear if the best conduct is to perform a superficial inguinal lymphadenectomy (limited lymphadenectomy or, on the contrary, a pelvic lymphadenectomy (extended or combined inguinal lymphadenectomy. It is proposed the postsentinel node as anew diagnostic method capable of predicting pelvic node involvement and thus reducing the number of unnecessary pelvic dissections.

Eduardo Torregroza-Diazgranados

2007-03-01

45

Potassium permeability of Rickettsia prowazekii.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The potassium permeability of Rickettsia prowazekii was characterized by chemical measurement of the intracellular sodium and potassium pools and isotopic flux measurements with 86Rb+ as a tracer. R. prowazekii, in contrast to Escherichia coli, did not maintain a high potassium-to-sodium ratio in their cytoplasm except when the potassium-to-sodium ratio in the extracellular medium was high or when the extracellular concentrations of both cations were low (ca. 1 mM). Both influx and efflux ass...

Winkler, H. H.

1984-01-01

46

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 fe [...] ita 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. Abstract in english 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 detect [...] ion 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.

1999-10-01

47

On the nature of obligate intracellular symbiosis of rickettsiae--Rickettsia prowazekii cells import mitochondrial porin.  

Science.gov (United States)

Mitochondrial porin was identified in Rickettsia prowazekii by Western blot analysis of whole cells and membrane fractions with monoclonal antibody against porin VDAC 1 of animal mitochondria. Using the BLAST server, no protein sequences homologous to mitochondrial porin were found among the rickettsial genomes. Rickettsiae also do not contain their own porin. The protein imported by rickettsiae is weakly extracted by nonionic detergents and, like porin in mitochondria, is insensitive to proteinase K in whole cells. Immunocytochemical analysis showed that it localizes to the outer membrane of the bacterial cells. These data support an earlier suggestion about import by rickettsiae of indispensable proteins from cytoplasm of the host cell as a molecular basis of obligate intracellular parasitism. They are also consistent with the hypothesis invoking a transfer of genes specifying surface proteins from the last common ancestor of rickettsiae and mitochondria to the host genome, and preservation by rickettsiae of the primitive ability to import these proteins. PMID:16903827

Emelyanov, V V; Vyssokikh, M Yu

2006-07-01

48

S-Adenosylmethionine Transport in Rickettsia prowazekii  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rickettsia prowazekii, the causative agent of epidemic typhus, is an obligate, intracellular, parasitic bacterium that grows within the cytoplasm of eucaryotic host cells. Rickettsiae exploit this intracellular environment by using transport systems for the compounds available in the host cell's cytoplasm. Analysis of the R. prowazekii Madrid E genome sequence revealed the presence of a mutation in the rickettsial metK gene, the gene encoding the enzyme responsible for the synthesis of S-aden...

Tucker, Aimee M.; Winkler, Herbert H.; Driskell, Lonnie O.; Wood, David O.

2003-01-01

49

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 SciELO Cuba | Language: Spanish 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 segunda 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 eva [...] luate 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/BPVNr/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.

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

2011-12-01

50

Molecular detection of Rickettsia africae, Rickettsia aeschlimannii, and Rickettsia sibirica mongolitimonae in camels and Hyalomma spp. ticks from Israel.  

Science.gov (United States)

In this study, we aimed to identify and genetically characterize spotted fever group (SFG) rickettsiae in ticks, domestic one-humped camels, and horses from farms and Bedouin communities in southern Israel. A total of 618 ixodid ticks (Hyalomma dromedarii, Hyalomma turanicum, Hyalomma excavatum, and Hyalomma impeltatum) collected from camels and horses, as well as 152 blood samples from 148 camels and four horses were included in the study. Initial screening for rickettsiae was carried out by targeting the gltA gene. Positive samples were further analyzed for rickettsial ompA, 17kDa, ompB, and 16S rRNA genes. Rickettsia aeschlimannii DNA was detected in the blood of three camels and 14 ticks (H. dromedarii, H. turanicum, and H. excavatum). Rickettsia africae was found in six ticks (H. turanicum, H. impeltatum, H. dromedarii, and H. excavatum). In addition, Rickettsia sibirica mongolitimonae was detected in one H. turanicum tick. These findings represent the first autochthonous detection of R. africae in Israel. Previous detections of R. africae in Asia were reported from the Sinai Peninsula (Egypt) and Istanbul, only. Furthermore, we report for the first time the finding of R. aeschlimannii in H. turanicum and H. excavatum ticks, as well as the first identification of R. sibirica mongolitimonae in H. turanicum ticks. The tick species identified to harbor R. africae and other SFG rickettsiae have been reported to occasionally feed on people, and, therefore, physicians should be aware of the possible exposure of local communities and travelers, especially those in contact with camels, to these tick-borne rickettsial pathogens. PMID:24107206

Kleinerman, Gabriela; Baneth, Gad; Mumcuoglu, Kosta Y; van Straten, Michael; Berlin, Dalia; Apanaskevich, Dmitry A; Abdeen, Ziad; Nasereddin, Abed; Harrus, Shimon

2013-12-01

51

Proline transport and metabolism in Rickettsia prowazekii.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Purified Rickettsia prowazekii cells were able to transport L-proline. The influx of this amino acid had a Kt of 14 microM and a Vmax of about 64 pmol/min per mg of protein. Proline could not be transported by heat-killed or metabolically poisoned rickettsiae or at 0 degrees C. The uptake of proline was linear for almost 2 h. More than 90% of the accumulated intracellular radioactivity was proline. This intracellular pool could not be chased out of the cell by excess non-radioactive proline a...

Winkler, H. H.; Daugherty, R. M.

1984-01-01

52

Identificación de Rickettsia andeanae en dos regiones de Chile / Detection of Rickettsia andeanae in two regions of Chile  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Introducción: Candidatus 'Rickettsia andeanae', especie de reciente reconocimiento y rol patógeno no precisado, ha sido identificada en garrapatas del género Amblyomma en Perú, E.U.A. y AArgentina y recientemente en Chile, en un espécimen de Amblyomma triste de un sector rural de Arica. Objetivo: De [...] terminar presencia de agentes rickettsiales en garrapatas de perros domésticos de dos regiones de Chile. Métodos: Estudio transversal, descriptivo, en las regiones de Coquimbo y La Araucanía, con muestreo domiciliario en las ciudades de Coquimbo y AAngol y localidades rurales cercanas, en primavera-verano 2011-2012. Se examinó un perro por vivienda, recolectando garrapatas si estaban presentes; luego de su identificación taxonómica fueron sometidas a amplificación y secuenciación de los genes gltA y ompA. Resultados: Se examinaron 462 perros, 255 tenían garrapatas (55%). En las ciudades se encontró exclusivamente Rhipicephalus sanguineus; en las localidades rurales además Amblyomma tigrinum. Las secuencias obtenidas en 12 especímenes de A. tigrinum correspondieron a Candidatus 'Rickettsia andeanae'. Conclusiones: Se documenta presencia de R. andeanae en dos regiones distantes de Chile, lo que se suma a su reciente hallazgo en el extremo norte del país. Este nuevo agente rickettsial se limita a garrapatas del género Amblyomma y a zonas rurales, lo que concuerda con lo documentado en otros países y con el hábitat de esta garrapata. Abstract in english Introduction: Candidatus 'Rickettsia andeanae' is recently recognized specie, with no attributed pathogenic role so far. It has been reported in Amblyomma ticks from Peru, USA and Argentina, and recently in Chile, in one specimen of Amblyomma triste from a rural locality in Arica. Objective: To dete [...] rmine the presence of rickettsial agents in ticks from domestic dogs from two Chilean regions. Methods: A transversal descriptive study in Coquimbo and La Araucanía regions, consisted in households sampling in the cities of Coquimbo and Aingol and nearby rural localities, in spring-summer 2011-2012. One dog per house was examined and ticks were collected when present; after taxonomic identification, gltA and ompA genes were amplified and sequenced. Results: 462 dogs were examined, 255 had ticks (55%). In the cities just Rhipicephalus sanguineus was found; in rural localities also Amblyomma tigrinum. Obtained sequences in 12 specimens from A. tigrinum corresponded to Candidatus 'Rickettsia andeanae'. Conclusions: We documented the presence of R. andeanae in two distant Chilean regions, which is added to its recently finding in the Northern extreme of the country. This new rickettsial agent limits to Amblyomma ticks and rural areas, as it was reported in other American countries and corresponds with this tick habitat.

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

2013-08-01

53

Identificación de Rickettsia andeanae en dos regiones de Chile / Detection of Rickettsia andeanae in two regions of Chile  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Introducción: Candidatus 'Rickettsia andeanae', especie de reciente reconocimiento y rol patógeno no precisado, ha sido identificada en garrapatas del género Amblyomma en Perú, E.U.A. y AArgentina y recientemente en Chile, en un espécimen de Amblyomma triste de un sector rural de Arica. Objetivo: De [...] terminar presencia de agentes rickettsiales en garrapatas de perros domésticos de dos regiones de Chile. Métodos: Estudio transversal, descriptivo, en las regiones de Coquimbo y La Araucanía, con muestreo domiciliario en las ciudades de Coquimbo y AAngol y localidades rurales cercanas, en primavera-verano 2011-2012. Se examinó un perro por vivienda, recolectando garrapatas si estaban presentes; luego de su identificación taxonómica fueron sometidas a amplificación y secuenciación de los genes gltA y ompA. Resultados: Se examinaron 462 perros, 255 tenían garrapatas (55%). En las ciudades se encontró exclusivamente Rhipicephalus sanguineus; en las localidades rurales además Amblyomma tigrinum. Las secuencias obtenidas en 12 especímenes de A. tigrinum correspondieron a Candidatus 'Rickettsia andeanae'. Conclusiones: Se documenta presencia de R. andeanae en dos regiones distantes de Chile, lo que se suma a su reciente hallazgo en el extremo norte del país. Este nuevo agente rickettsial se limita a garrapatas del género Amblyomma y a zonas rurales, lo que concuerda con lo documentado en otros países y con el hábitat de esta garrapata. Abstract in english Introduction: Candidatus 'Rickettsia andeanae' is recently recognized specie, with no attributed pathogenic role so far. It has been reported in Amblyomma ticks from Peru, USA and Argentina, and recently in Chile, in one specimen of Amblyomma triste from a rural locality in Arica. Objective: To dete [...] rmine the presence of rickettsial agents in ticks from domestic dogs from two Chilean regions. Methods: A transversal descriptive study in Coquimbo and La Araucanía regions, consisted in households sampling in the cities of Coquimbo and Aingol and nearby rural localities, in spring-summer 2011-2012. One dog per house was examined and ticks were collected when present; after taxonomic identification, gltA and ompA genes were amplified and sequenced. Results: 462 dogs were examined, 255 had ticks (55%). In the cities just Rhipicephalus sanguineus was found; in rural localities also Amblyomma tigrinum. Obtained sequences in 12 specimens from A. tigrinum corresponded to Candidatus 'Rickettsia andeanae'. Conclusions: We documented the presence of R. andeanae in two distant Chilean regions, which is added to its recently finding in the Northern extreme of the country. This new rickettsial agent limits to Amblyomma ticks and rural areas, as it was reported in other American countries and corresponds with this tick habitat.

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

54

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

2008-06-01

55

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 SciELO Colombia | Language: Spanish 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 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. 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, 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.

2008-06-01

56

In Vitro Activities of Telithromycin (HMR 3647) against Rickettsia rickettsii, Rickettsia conorii, Rickettsia africae, Rickettsia typhi, Rickettsia prowazekii, Coxiella burnetii, Bartonella henselae, Bartonella quintana, Bartonella bacilliformis, and Ehrlichia chaffeensis  

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In vitro activities of telithromycin compared to those of erythromycin against Rickettsia spp., Bartonella spp., Coxiella burnetii, and Ehrlichia chaffeensis were determined. Telithromycin was more active than erythromycin against Rickettsia, Bartonella, and Coxiella burnetii, with MICs of 0.5 ?g/ml, 0.003 to 0.015 ?g/ml, and 1 ?g/ml, respectively, but was inactive against Ehrlichia chaffeensis.

Rolain, Jean-marc; Maurin, Max; Bryskier, Andre?; Raoult, Didier

2000-01-01

57

Antibodies against rickettsiae from spotted fever groups in horses from two mesoregions in the state of Santa Catarina, Brazil / Anticorpos contra rickettsias do grupo da febre maculosa em equinos de duas mesorregiões de Santa Catarina, Brasil  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese Bactérias do gênero Rickettsia são agentes da Febre Maculosa Brasileira (FMB), uma doença zoonótica, de difícil diagnóstico, rápida evolução e que pode levar o indivíduo à morte. Anticorpos contra Rickettsia spp. em equinos foram pesquisados, por meio da Reação de Imunofluorescência Indireta (RIFI?6 [...] 4), em 150 amostras de sangue colhidas de animais em duas mesorregiões de Santa Catarina (Planalto Serrano e Vale do Itajaí). A ocorrência de anticorpos contra Rickettsia spp. observada em equinos de duas mesorregiões de Santa Catarina foi de 18,66%, ocorrendo reações cruzadas em todas as amostras positivas para, no mínimo, duas das espécies testadas. Isoladamente, de acordo com as espécies, 25 (16,66%) amostras foram positivas para R. rickettsii, 15 (10%) para R. parkeri, 22 (14,66%) para R. amblyommii, 23 (15,33%) para R. rhipicephali, 16 (10,66%) para R. bellii e 19 (12,66%) para R. felis. Somente dois animais resultaram em um sorodiagnóstico conclusivo, um para Rickettsia bellii e outro para R. rickettsii, nas diluições máximas de 1:4096 e 1:512, respectivamente. A ocorrência de anticorpos contra Rickettsia spp. em equinos de duas mesorregiões de Santa Catarina indica a circulação de agentes da FMB nestes animais sentinela e ratificam a importância do estudo da febre maculosa no estado de Santa Catarina. Abstract in english Bacteria of the Rickettsia genus are agents of Brazilian Spotted Fever (BSF), a zoonotic disease which is difficult to diagnose, evolves quickly and can result in death. Antibodies against Rickettsia spp. in horses were studied, by means of Indirect Immunofluorescence Assay (IFAT ?64), in 150 blood [...] samples taken from animals in two Santa Catarina mesoregions (Planalto Serrano and Vale do Itajaí). The overall occurrence of Rickettsia spp. antibodies in horses was 18.66%, with cross-reactivity occurring in all positive samples for at least two of the species tested. Separately, according to the species, 25 (16.66%) samples were positive for R. rickettsii, 15 (10%) for R. parkeri, 22 (14.66%) for R. amblyommii, 23 (15.33%) for R. rhipicephali, 16 (10.66%) for R. bellii and 19 (12.66%) for R. felis. Only two animals resulted in a conclusive serodiagnosis, one for R. bellii and the other for R. rickettsii, at maximum dilutions of 1:4096 and 1:512, respectively. The occurrence of antibodies against Rickettsia spp. in horses from two mesoregions in the state of Santa Catarina indicates the movement of BSF agents in these sentinel animals and confirms the importance of studying spotted fever in the state of Santa Catarina.

A.P., Medeiros; A.B., Moura; A.P., Souza; V., Bellato; A.A., Sartor; A., Vieira-Neto; J., Moraes-Filho; M.B., Labruna.

1713-17-01

58

Antibodies against rickettsiae from spotted fever groups in horses from two mesoregions in the state of Santa Catarina, Brazil / Anticorpos contra rickettsias do grupo da febre maculosa em equinos de duas mesorregiões de Santa Catarina, Brasil  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese Bactérias do gênero Rickettsia são agentes da Febre Maculosa Brasileira (FMB), uma doença zoonótica, de difícil diagnóstico, rápida evolução e que pode levar o indivíduo à morte. Anticorpos contra Rickettsia spp. em equinos foram pesquisados, por meio da Reação de Imunofluorescência Indireta (RIFI?6 [...] 4), em 150 amostras de sangue colhidas de animais em duas mesorregiões de Santa Catarina (Planalto Serrano e Vale do Itajaí). A ocorrência de anticorpos contra Rickettsia spp. observada em equinos de duas mesorregiões de Santa Catarina foi de 18,66%, ocorrendo reações cruzadas em todas as amostras positivas para, no mínimo, duas das espécies testadas. Isoladamente, de acordo com as espécies, 25 (16,66%) amostras foram positivas para R. rickettsii, 15 (10%) para R. parkeri, 22 (14,66%) para R. amblyommii, 23 (15,33%) para R. rhipicephali, 16 (10,66%) para R. bellii e 19 (12,66%) para R. felis. Somente dois animais resultaram em um sorodiagnóstico conclusivo, um para Rickettsia bellii e outro para R. rickettsii, nas diluições máximas de 1:4096 e 1:512, respectivamente. A ocorrência de anticorpos contra Rickettsia spp. em equinos de duas mesorregiões de Santa Catarina indica a circulação de agentes da FMB nestes animais sentinela e ratificam a importância do estudo da febre maculosa no estado de Santa Catarina. Abstract in english Bacteria of the Rickettsia genus are agents of Brazilian Spotted Fever (BSF), a zoonotic disease which is difficult to diagnose, evolves quickly and can result in death. Antibodies against Rickettsia spp. in horses were studied, by means of Indirect Immunofluorescence Assay (IFAT ?64), in 150 blood [...] samples taken from animals in two Santa Catarina mesoregions (Planalto Serrano and Vale do Itajaí). The overall occurrence of Rickettsia spp. antibodies in horses was 18.66%, with cross-reactivity occurring in all positive samples for at least two of the species tested. Separately, according to the species, 25 (16.66%) samples were positive for R. rickettsii, 15 (10%) for R. parkeri, 22 (14.66%) for R. amblyommii, 23 (15.33%) for R. rhipicephali, 16 (10.66%) for R. bellii and 19 (12.66%) for R. felis. Only two animals resulted in a conclusive serodiagnosis, one for R. bellii and the other for R. rickettsii, at maximum dilutions of 1:4096 and 1:512, respectively. The occurrence of antibodies against Rickettsia spp. in horses from two mesoregions in the state of Santa Catarina indicates the movement of BSF agents in these sentinel animals and confirms the importance of studying spotted fever in the state of Santa Catarina.

A.P., Medeiros; A.B., Moura; A.P., Souza; V., Bellato; A.A., Sartor; A., Vieira-Neto; J., Moraes-Filho; M.B., Labruna.

59

Isolation of Rickettsia prowazekii with reduced sensitivity to gamma interferon.  

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The growth of Rickettsia prowazekii Madrid E was monitored in mouse L929 cells subcultured for several weeks in the presence of gamma interferon (IFN-gamma) to determine whether the rickettsiae would be eliminated from or would persist in these cultures. R. prowazekii exhibited two distinct patterns in these IFN-gamma-treated cultures. In some cases, IFN-gamma-induced inhibition of rickettsial growth led to elimination of the rickettsiae from the L929 cell cultures; in other cases, the initia...

Turco, J.; Winkler, H. H.

1989-01-01

60

Serologic evidence of human Rickettsia infection found in three locations in Panamá / Evidencia serológica de infecciones de Rickettsia en humanos provenientes de tres localidades de Panamá  

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Full Text Available SciELO Colombia | Language: English Abstract in spanish Introducción. Desde mediados del siglo pasado, se conocen en Panamá casos de rickettsiosis, cuando fueron reportados brotes de tifus en ratones y de fiebres manchadas. A partir de entonces, poca información se tiene sobre su prevalencia en este país, lo cual se debe principalmente a que son confundi [...] dos con otras enfermedades. Objetivos. El objetivo de este trabajo fue demostrar la presencia de rickettsiosis en humanos provenientes de tres localidades de Panamá, que corresponden a zonas agropecuarias, cercanas a bosques, o que trabajaban en zoológicos. Materiales y métodos. Se escogieron tres localidades para este estudio: Tortí (provincia de Panamá), El Valle de Antón (provincia de Coclé) y el Parque Municipal Summit en Ciudad de Panamá. Los voluntarios firmaron un consentimiento informado, además de responder un cuestionario. De cada voluntario se extrajo sangre venosa, la que fue analizada por medio de inmunoflorescencia indirecta, utilizando kits comerciales y láminas sensibilizadas con antígenos cultivados de Rickettsia rickettsii y Rickettsia amblyommii . Resultados. Se tomaron muestras de 97 voluntarios, 25 en Tortí, 37 en El Valle de Antón y 35 en el Parque Municipal Summit. De estos, 38 (39 %) de las muestras fueron positivas en algunas de las dos técnicas practicadas: 8 (32 %) en Tortí, 18 (48 %) en El Valle y 12 (34 %) en el Parque Municipal Summit. Conclusión. Se demuestra una alta prevalencia de anticuerpos contra Rickettsia del grupo de las fiebres manchadas en las tres áreas de estudio, además de presentarse evidencia de títulos para Rickettsia del grupo tifus en El Valle de Antón. Estas zonas podrían considerarse como endémicas por rickettsiosis, ya que existen condiciones que permiten el mantenimiento de las mismas. Abstract in english Introduction: Since the middle of last century, cases of rickettsiosis have been found in Panamá when outbreaks of murine typhus and spotted fever were reported. Since then, little information exists about its prevalence in this country, since it is most often is misdiagnosed as another disease. Obj [...] ectives: The aim of this paper is to demonstrate the presence of Rickettsia infections in humans in three locations in Panamá. These locations are agricultural areas, near forested areas or those who work in zoo. Materials and methods: Three locations where chosen for this study: Tortí, El Valle de Antón and workers in the Summit Municipal Park in Panamá City. All volunteers signed an informed consent and answered a questionnaire. The samples were analyzed for the detection of rickettsial spotted fever and typhus group by the indirect immunofluorescence (using commercial kits) and antigens of Rickettsia rickettsii and R. amblyommii. Results: Blood samples were taken from 97 volunteers in Tortí (25), El Valle de Anton (37) and Summit Municipal Park (35). Of these, a total of 38 (39%) samples reacted to one of the two methods: eight (32%) in Tortí, 18 (48%) in El valle and 12 (34%) in Summit Municipal Park. Conclusion: The results show a high prevalence of antibodies to Rickettsia belonging to the spotted fever group in each of the three study areas, in addition to presenting evidence of the typhus group Rickettsia in El Valle de Anton. These areas could be considered endemic for rickettsiosis as there are conditions for maintaining them.

Sergio E, Bermúdez; Cirilo R, Lyons; Gleydis G, García; Yamitzel L, Zaldíva; Amanda, Gabster; Griselda B, Arteaga.

2013-09-01

 
 
 
 
61

Serologic evidence of human Rickettsia infection found in three locations in Panamá / Evidencia serológica de infecciones de Rickettsia en humanos provenientes de tres localidades de Panamá  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: English Abstract in spanish Introducción. Desde mediados del siglo pasado, se conocen en Panamá casos de rickettsiosis, cuando fueron reportados brotes de tifus en ratones y de fiebres manchadas. A partir de entonces, poca información se tiene sobre su prevalencia en este país, lo cual se debe principalmente a que son confundi [...] dos con otras enfermedades. Objetivos. El objetivo de este trabajo fue demostrar la presencia de rickettsiosis en humanos provenientes de tres localidades de Panamá, que corresponden a zonas agropecuarias, cercanas a bosques, o que trabajaban en zoológicos. Materiales y métodos. Se escogieron tres localidades para este estudio: Tortí (provincia de Panamá), El Valle de Antón (provincia de Coclé) y el Parque Municipal Summit en Ciudad de Panamá. Los voluntarios firmaron un consentimiento informado, además de responder un cuestionario. De cada voluntario se extrajo sangre venosa, la que fue analizada por medio de inmunoflorescencia indirecta, utilizando kits comerciales y láminas sensibilizadas con antígenos cultivados de Rickettsia rickettsii y Rickettsia amblyommii . Resultados. Se tomaron muestras de 97 voluntarios, 25 en Tortí, 37 en El Valle de Antón y 35 en el Parque Municipal Summit. De estos, 38 (39 %) de las muestras fueron positivas en algunas de las dos técnicas practicadas: 8 (32 %) en Tortí, 18 (48 %) en El Valle y 12 (34 %) en el Parque Municipal Summit. Conclusión. Se demuestra una alta prevalencia de anticuerpos contra Rickettsia del grupo de las fiebres manchadas en las tres áreas de estudio, además de presentarse evidencia de títulos para Rickettsia del grupo tifus en El Valle de Antón. Estas zonas podrían considerarse como endémicas por rickettsiosis, ya que existen condiciones que permiten el mantenimiento de las mismas. Abstract in english Introduction: Since the middle of last century, cases of rickettsiosis have been found in Panamá when outbreaks of murine typhus and spotted fever were reported. Since then, little information exists about its prevalence in this country, since it is most often is misdiagnosed as another disease. Obj [...] ectives: The aim of this paper is to demonstrate the presence of Rickettsia infections in humans in three locations in Panamá. These locations are agricultural areas, near forested areas or those who work in zoo. Materials and methods: Three locations where chosen for this study: Tortí, El Valle de Antón and workers in the Summit Municipal Park in Panamá City. All volunteers signed an informed consent and answered a questionnaire. The samples were analyzed for the detection of rickettsial spotted fever and typhus group by the indirect immunofluorescence (using commercial kits) and antigens of Rickettsia rickettsii and R. amblyommii. Results: Blood samples were taken from 97 volunteers in Tortí (25), El Valle de Anton (37) and Summit Municipal Park (35). Of these, a total of 38 (39%) samples reacted to one of the two methods: eight (32%) in Tortí, 18 (48%) in El valle and 12 (34%) in Summit Municipal Park. Conclusion: The results show a high prevalence of antibodies to Rickettsia belonging to the spotted fever group in each of the three study areas, in addition to presenting evidence of the typhus group Rickettsia in El Valle de Anton. These areas could be considered endemic for rickettsiosis as there are conditions for maintaining them.

Sergio E, Bermúdez; Cirilo R, Lyons; Gleydis G, García; Yamitzel L, Zaldíva; Amanda, Gabster; Griselda B, Arteaga.

62

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".

Jeffery Kathryn

2007-08-01

63

Isolation of species-specific protein antigens of Rickettsia typhi and Rickettsia prowazekii for immunodiagnosis and immunoprophylaxis.  

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A simple procedure for the selective isolation of the protective species-specific protein antigens (SPAs) of Rickettsia typhi and Rickettsia prowazekii was developed to permit use of the SPAs in the immunodiagnosis and immunoprophylaxis of typhus infections. Although the SPAs were readily extracted from lysozyme- or detergent-treated rickettsiae, as measured by rocket immunoelectrophoresis, other polypeptides were also present, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophor...

Dasch, G. A.

1981-01-01

64

Serosurvey of Rickettsia typhi and Rickettsia felis in HIV-infected patients.  

Science.gov (United States)

Consistent with the effects of HIV on cell-mediated immunity, an increased susceptibility to intracellular microorganisms has been observed. Rickettsiae are obligate intracellular microorganisms. The aim of this study was to examine Rickettsia typhi and Rickettsia felis infections in HIV+ population. Sera of 341 HIV+ patients were evaluated by indirect immunofluorescent assay. Age, sex, residential locality, risk behavior, stage according to criteria of the Center for Disease Control and Prevention, CD4+/CD8+ T cells, Hepatitis B antigen, and Hepatitis C serology were surveyed. Seroprevalences of R. typhi and R. felis infection were 7.6% and 4.4%, respectively. No associations were found between seropositivities and the assessed variables. Findings were similar to those obtained in healthy subjects from the same region. PMID:24467705

Nogueras, María Mercedes; Pons, Immaculada; Sanfeliu, Isabel; Sala, Montserrat; Segura, Ferran

2014-04-01

65

Permeability of Rickettsia prowazekii to NAD  

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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.

Atkinson, W.H.; Winkler, H.H.

1989-02-01

66

Transformation of Rickettsia prowazekii to Rifampin Resistance  

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Rickettsia prowazekii, the causative agent of epidemic typhus, is an obligate intracellular parasitic bacterium that grows directly within the cytoplasm of the eucaryotic host cell. The absence of techniques for genetic manipulation hampers the study of this organism’s unique biology and pathogenic mechanisms. To establish the feasibility of genetic manipulation in this organism, we identified a specific mutation in the rickettsial rpoB gene that confers resistance to rifampin and used it t...

Rachek, Lyudmila I.; Tucker, Aimee M.; Winkler, Herbert H.; Wood, David O.

1998-01-01

67

Analysis of the peptidoglycan of Rickettsia prowazekii.  

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In the present study, peptidoglycan from Rickettsia prowazekii, an obligate intracellular bacterium, was purified. The rickettsial peptidoglycan is like that of gram-negative bacteria; that is, it is sodium dodecyl sulfate insoluble, lysozyme sensitive, and composed of glutamic acid, alanine, and diaminopimelic acid in a molar ratio of 1.0:2.3:1.0. The small amount of lysine found in the peptidoglycan preparation suggests that a peptidoglycan-linked lipoprotein(s) may be present in the ricket...

Pang, H.; Winkler, H. H.

1994-01-01

68

The realities of biodefense vaccines against Rickettsia  

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Rickettsia prowazekii, R. rickettsii, R. conorii, and R. typhi are serious biologic weapon threats because of high infectivity of low dose aerosols, stable small particle aerosol infectivity, virulence causing severe disease, difficulty in establishing a timely diagnosis, ineffectiveness of usual empiric treatments, potential for engineered complete antimicrobial resistance, lower level of immunity, availability of the agents in nature, and feasibility of propagation, stabilization, and dispe...

Walker, David H.

2009-01-01

69

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 hy[adenine-2,8-3H]NAD at the locus of NAD hydrolysis and translocation

70

Rickettsia felis: a new species of pathogenic rickettsia isolated from cat fleas.  

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A flea-borne rickettsia, previously referred to as ELB, has been implicated as a cause of human illness. Using sequence data obtained from a fragment of the citrate synthase gene, we compared ELB, Rickettsia australis, R. rickettsii, and R. akari with the louse-borne R. prowazekii. We tallied 24 base pair differences between ELB and R. prowazekii and 25 between R. rickettsii and R. prowazekii; there were 30 base pair differences between R. australis and R. prowazekii and 29 between R. akari a...

Higgins, J. A.; Radulovic, S.; Schriefer, M. E.; Azad, A. F.

1996-01-01

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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.

Reimerink Johan HJ

2010-06-01

72

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish 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 disociada [...] s 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. 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 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.

73

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

2003-03-01

74

The realities of biodefense vaccines against Rickettsia.  

Science.gov (United States)

Rickettsia prowazekii, R. rickettsii, R. conorii, and R. typhi are serious biologic weapon threats because of high infectivity of low dose aerosols, stable small particle aerosol infectivity, virulence causing severe disease, difficulty in establishing a timely diagnosis, ineffectiveness of usual empiric treatments, potential for engineered complete antimicrobial resistance, lower level of immunity, availability of the agents in nature, and feasibility of propagation, stabilization, and dispersal. Infection induces long-term immunity, killed rickettsial vaccines stimulate incomplete protection, and a live attenuated mutant stimulates strong immunity but reverts to virulence. Prospects for rational development of a safe, effective live attenuated vaccine are excellent. PMID:19837287

Walker, David H

2009-11-01

75

Natural infection of dogs on Cape Cod with Rickettsia rickettsii.  

Science.gov (United States)

Four isolates of rickettsiae from sick dogs on Cape Cod, Mass., were serologically identical to isolates of Rickettsia rickettsii from human patients with Rocky Mountain spotted fever. The antigenic analysis used the indirect fluorescent-antibody test and antisera prepared in mice to each of the isolates and to reference strains of R. rickettsii and Rickettsia montana. Serological responses of infected dogs were specific for R. rickettsii, although antibodies to R. montana were also detected in the sera of most of the canines. PMID:114534

Feng, W C; Murray, E S; Rosenberg, G E; Spielman, J M; Waner, J L

1979-09-01

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Acquisition of polyamines by the obligate intracytoplasmic bacterium Rickettsia prowazekii.  

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Both the polyamine content and the route of acquisition of polyamines by Rickettsia prowazekii, an obligate intracellular parasitic bacterium, were determined. The rickettsiae grew normally in an ornithine decarboxylase mutant of the Chinese hamster ovary (C55.7) cell line whether or not putrescine, which this host cell required in order to grow, was present. The rickettsiae contained approximately 6 mM putrescine, 5 mM spermidine, and 3 mM spermine when cultured in the presence or absence of...

Speed, R. R.; Winkler, H. H.

1990-01-01

77

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

2013-06-01

78

Regulatory properties of citrate synthase from Rickettsia prowazekii.  

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Citrate synthase [citrate (si)-synthase] (EC 4.1.3.7) was partially purified from extracts of highly purified typhus rickettsiae (Rickettsia prowazekii). Molecular exclusion and affinity column chromatography were used to prepare 200-fold-purified citrate synthase that contained no detectable malate dehydrogenase (EC 1.1.1.37) activity. Rickettsial malate dehydrogenase also was partially purified (200-fold) via this purification procedure. Catalytically active citrate synthase exhibited a rel...

Phibbs, P. V.; Winkler, H. H.

1982-01-01

79

Rickettsia prowazekii requires host cell serine and glycine for growth.  

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The growth requirement of Rickettsia prowazekii for the amino acids serine and glycine was assessed in both wild-type cell lines and a mutant cell line. X-irradiated L929 cells supported the growth of R. prowazekii when the cells were incubated in Eagle minimal essential medium supplemented with serum. In contrast, in this medium, X-irradiated Vero cells did not support the growth of rickettsiae unless cycloheximide, serine, or glycine was added. Other nonessential amino acids, additional glu...

Austin, F. E.; Turco, J.; Winkler, H. H.

1987-01-01

80

Acquisition of thymidylate by the obligate intracytoplasmic bacterium Rickettsia prowazekii.  

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The pathway for the acquisition of thymidylate in the obligate bacterial parasite Rickettsia prowazekii was determined. R. prowazekii growing in host cells with or without thymidine kinase failed to incorporate into its DNA the [3H]thymidine added to the culture. In the thymidine kinase-negative host cells, the label available to the rickettsiae in the host cell cytoplasm would have been thymidine, and in the thymidine kinase-positive host cells, it would have been both thymidine and TMP. Fur...

Speed, R. R.; Winkler, H. H.

1991-01-01

 
 
 
 
81

Reduction of ribonucleotides by the obligate intracytoplasmic bacterium Rickettsia prowazekii.  

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Rickettsia prowazekii, an obligate intracellular parasitic bacterium, was shown to have a ribonucleotide reductase that would allow the rickettsiae to obtain the deoxyribonucleotides needed for DNA synthesis from rickettsial ribonucleotides rather than from transport. In the presence of hydroxyurea, R. prowazekii failed to grow in mouse L929 cells or SC2 cells (a hydroxyurea-resistant cell line), which suggested that R. prowazekii contains a functional ribonucleotide reductase. This enzymatic...

Cai, J.; Speed, R. R.; Winkler, H. H.

1991-01-01

82

In Vitro Studies of Rickettsia-Host Cell Interactions: Ultrastructural Study of Rickettsia prowazekii-Infected Chicken Embryo Fibroblasts  

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Secondary chicken embryo fibroblasts infected in suspension with the Breinl strain of Rickettsia prowazekii and grown in monolayer culture were examined by both transmission and scanning electron microscopy at specific intervals after infection to study the effects of prolonged intracellular growth on the fine structure of the host cell and the rickettsiae. Cytopathological changes in the infected host cells were not apparent until late in the intracellular growth cycle when the cells began t...

Silverman, David J.; Wisseman, Charles L.; Waddell, Anna

1980-01-01

83

Ixodes ricinus ticks are reservoir hosts for Rickettsia helvetica and potentially carry flea-borne Rickettsia species  

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Background - Hard ticks have been identified as important vectors of rickettsiae causing the spotted fever syndrome. Tick-borne rickettsiae are considered to be emerging, but only limited data are available about their presence in Western Europe, their natural life cycle and their reservoir hosts. Ixodes ricinus, the most prevalent tick species, were collected and tested from different vegetation types and from potential reservoir hosts. In one biotope area, the annual and seasonal variabilit...

Sprong, H.; Wielinga, P. R.; Fonville, M.; Reusken, C.; Brandenburg, A. H.; Borgsteede, F. H. M.

2009-01-01

84

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

2010-03-01

85

Detection of an undescribed Rickettsia sp. in Ixodes boliviensis from Costa Rica.  

Science.gov (United States)

Ixodes boliviensis is a tick of carnivores that is common on domestic dogs. The only Rickettsia that has been detected previously in this species is 'Candidatus Rickettsia andeanae'. We report the detection of an undescribed Rickettsia sp., named strain IbR/CRC, in I. boliviensis collected from dogs in Costa Rica. Analyses of gltA, ompA, and htrA partial sequences place Rickettsia sp. strain IbR/CRC in the group of R. monacensis, also close to an endosymbiont of Ixodes scapularis and other undescribed rickettsiae. It was not possible to isolate Rickettsia sp. strain IbR/CRC in Vero E6 or C6/36 cell lines. Isolation and further characterization of Rickettsia sp. strain IbR/CRC and the other undescribed rickettsiae are required to determine their taxonomic status and pathogenic potential. PMID:25132535

Troyo, Adriana; Moreira-Soto, Andrés; Carranza, Marco; Calderón-Arguedas, Olger; Hun, Laya; Taylor, Lizeth

2014-10-01

86

Detection and characterization of mouse monoclonal antibodies to epidemic typhus rickettsiae.  

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A solid-phase immunofluorometric assay was used to detect mouse monoclonal antibodies to epidemic typhus rickettsiae, Rickettsia prowazekii (the immunizing antigen), and to murine typhus rickettsiae, Rickettsia typhi, a related antigen. Of the 649 hybridoma cultures obtained, 628 contained antibodies either to R. prowazekii or to both R. prowazekii and R. typhi. A total of 72 cultures were cloned by limiting dilution and yielded 137 antibody-producing clones. Of these, 104 produced antibodies...

Black, C. M.; Tzianabos, T.; Roumillat, L. F.; Redus, M. A.; Mcdade, J. E.; Reimer, C. B.

1983-01-01

87

Tuberculosis ganglionar cervical: ¿Pensamos en ella, o nos sorprende? / Neck node tuberculosis: Do we consider it... or does it pop up?  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Revisamos las características clínicas, diagnóstico y manejo de la tuberculosis (TB) cervical, así como resaltamos su importancia por su carácter epidémico. Presentamos dos pacientes afectados por tumoraciones laterocervicales subagudas, escasa sintomatología y excelente evolución tras su diagnóstic [...] o de TB ganglionar cervical y tratamiento antibiótico. La TB es una enfermedad que en la actual sociedad globalizada, puede encontrarse prácticamente cualquier especialista, por lo que debemos mantener un alto nivel de alerta y conocerla con detalle, para poder orientar su diagnóstico y facilitar su tratamiento precoz. Abstract in english We review tuberculosis clinical features, diagnosis and management as well as remark the importance of its epidemic nature. Study based on 2 patients suffering from eye-catching subacute neck lumps, sparsely symptomatic and excellent evolution after neck node TB diagnosis and antibiotic therapy TB r [...] epresents a disease that, given our present time globalization, may be faced by many different specialists. That is why we must be on alert and be aware of its profile, in order to guess the right diagnosis and offer therapy.

Miguel Alberto, Rodríguez-Pérez; Fernando, Aguirre-García.

88

Serological evidence of typhus group rickettsia in a homeless population in Houston, Texas.  

Science.gov (United States)

We tested sera from 176 homeless people in Houston 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 against Rickettsia typhi (murine typhus). PMID:18697325

Reeves, Will K; Murray, Kristy O; Meyer, Tamra E; Bull, Lara M; Pascua, Rhia F; Holmes, Kelly C; Loftis, Amanda D

2008-06-01

89

Detection of Rickettsia felis, Rickettsia typhi, Bartonella Species and Yersinia pestis in Fleas (Siphonaptera) from Africa  

Science.gov (United States)

Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia pestis in domestic and urban flea populations in tropical and subtropical African countries. Methodology/Principal findings Fleas collected in Benin, the United Republic of Tanzania and the Democratic Republic of the Congo were investigated for the presence and identity of Rickettsia spp., Bartonella spp. and Yersinia pestis using two qPCR systems or qPCR and standard PCR. In Xenopsylla cheopis fleas collected from Cotonou (Benin), Rickettsia typhi was detected in 1% (2/199), and an uncultured Bartonella sp. was detected in 34.7% (69/199). In the Lushoto district (United Republic of Tanzania), R. typhi DNA was detected in 10% (2/20) of Xenopsylla brasiliensis, and Rickettsia felis was detected in 65% (13/20) of Ctenocephalides felis strongylus, 71.4% (5/7) of Ctenocephalides canis and 25% (5/20) of Ctenophthalmus calceatus calceatus. In the Democratic Republic of the Congo, R. felis was detected in 56.5% (13/23) of Ct. f. felis from Kinshasa, in 26.3% (10/38) of Ct. f. felis and 9% (1/11) of Leptopsylla aethiopica aethiopica from Ituri district and in 19.2% (5/26) of Ct. f. strongylus and 4.7% (1/21) of Echidnophaga gallinacea. Bartonella sp. was also detected in 36.3% (4/11) of L. a. aethiopica. Finally, in Ituri, Y. pestis DNA was detected in 3.8% (1/26) of Ct. f. strongylus and 10% (3/30) of Pulex irritans from the villages of Wanyale and Zaa. Conclusion Most flea-borne infections are neglected diseases which should be monitored systematically in domestic rural and urban human populations to assess their epidemiological and clinical relevance. Finally, the presence of Y. pestis DNA in fleas captured in households was unexpected and raises a series of questions regarding the role of free fleas in the transmission of plague in rural Africa, especially in remote areas where the flea density in houses is high. PMID:25299702

Leulmi, Hamza; Socolovschi, Cristina; Laudisoit, Anne; Houemenou, Gualbert; Davoust, Bernard; Bitam, Idir; Raoult, Didier; Parola, Philippe

2014-01-01

90

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish 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 aqu [...] ellas 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 (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 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

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

2007-12-01

91

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish 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 aqu [...] ellas 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 (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 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

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

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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

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Genotypic characterization of Rickettsiae by DNA probes generated from Rickettsia Prowazekii DNA  

International Nuclear Information System (INIS)

Southern blot analysis of HindIII-cleaved rickettsial DNA was used for genotypic characterization of the typhus group (TG) species (R. prowazekii, R. typhi, R. canada) and a few species were of the spotted fever group (SFG)rickettsiae (R. sibirica, R. conorii, R. akari). Four different DNA probes were employed. PBH11 and PBH13 probes were morphospecific HindIII fragment of R prowazekii DNA. MW218 probe contained the gene for 51 K antigen and MW264 probe contained the citrate synthase gene of R. prowazekii. All the probes hybridized with the tested TG and SFG rickettsial DNAs, forming from 1 to 5 bands, but they did not with R. tsutsudamushi or C. burnetii DNAs. All the probes demonstrated specific hybridization pattern with TG species and R. akari. PBH11. PBH13 and MW264 probes clearly distinguished R. sibirica and R. conorii from the other tested rickettsiae, but not from each other. However, these two species differed slightly with MW218 probe. Several strains of each species were analyzed in this way and except for strains of R. conorii identical intra-species pattern were obtained. These data lead us to consider the obtained hybridization patterns as criteria for genotypic identification. (author)

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Rickettsia conorii israelensis in Rhipicephalus sanguineus ticks, Sardinia, Italy.  

Science.gov (United States)

The presence of tick-borne Rickettsia spp. was examined by PCR using DNA samples extracted from 254 ticks collected from mammals originating from northern and eastern Sardinia, Italy. The spotted fever group rickettsial agent Rickettsia conorii israelensis was detected in 3 Rhipicephalus sanguineus ticks from a dog for the first time in this geographical area. In addition, Ri. massiliae, Ri. slovaca, and Ri. aeschlimannii were detected in Rh. turanicus, Rh. sanguineus, Dermacentor marginatus, and Hyalomma marginatum marginatum ticks from dogs, goats, wild boar, and horse. Moreover, Candidatus Rickettsia barbariae was detected in 2 Rh. turanicus ticks from goats. The detection of Ri. conorii israelensis, an emergent agent which causes Israeli spotted fever, increases our knowledge on tick-borne rickettsioses in Sardinia. PMID:24852264

Chisu, Valentina; Masala, Giovanna; Foxi, Cipriano; Socolovschi, Cristina; Raoult, Didier; Parola, Philippe

2014-06-01

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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 SciELO Colombia | Language: English 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 aislar 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 wa [...] s 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.

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 granu [...] lomas 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. Abstract in english 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 biopsie [...] s, 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.

97

Ixodes ricinus ticks are reservoir hosts for Rickettsia helvetica and potentially carry flea-borne Rickettsia species  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Hard ticks have been identified as important vectors of rickettsiae causing the spotted fever syndrome. Tick-borne rickettsiae are considered to be emerging, but only limited data are available about their presence in Western Europe, their natural life cycle and their reservoir hosts. Ixodes ricinus, the most prevalent tick species, were collected and tested from different vegetation types and from potential reservoir hosts. In one biotope area, the annual and seasonal variability of rickettsiae infections of the different tick stages were determined for 9 years. Results The DNA of the human pathogen R. conorii as well as R. helvetica, R. sp. IRS and R. bellii-like were found. Unexpectedly, the DNA of the highly pathogenic R. typhi and R. prowazekii and 4 other uncharacterized Rickettsia spp. related to the typhus group were also detected in I. ricinus. The presence of R. helvetica in fleas isolated from small rodents supported our hypothesis that cross-infection can occur under natural conditions, since R. typhi/prowazekii and R. helvetica as well as their vectors share rodents as reservoir hosts. In one biotope, the infection rate with R. helvetica was ~66% for 9 years, and was comparable between larvae, nymphs, and adults. Larvae caught by flagging generally have not yet taken a blood meal from a vertebrate host. The simplest explanation for the comparable prevalence of R. helvetica between the defined tick stages is, that R. helvetica is vertically transmitted through the next generation with high efficiency. The DNA of R. helvetica was also present in whole blood from mice, deer and wild boar. Conclusion Besides R. helvetica, unexpected rickettsiae are found in I. ricinus ticks. We propose that I. ricinus is a major reservoir host for R. helvetica, and that vertebrate hosts play important roles in the further geographical dispersion of rickettsiae.

Gaasenbeek Cor

2009-09-01

98

Ixodes ricinus ticks are reservoir hosts for Rickettsia helvetica and potentially carry flea-borne Rickettsia species  

DEFF Research Database (Denmark)

ABSTRACT: BACKGROUND: Hard ticks have been identified as important vectors of rickettsiae causing the spotted fever syndrome. Tick-borne rickettsiae are considered to be emerging, but only limited data are available about their presence in Western Europe, their natural life cycle and their reservoir hosts. Ixodes ricinus, the most prevalent tick species, were collected and tested from different vegetation types and from potential reservoir hosts. In one biotope area, the annual and seasonal variability of rickettsiae infections of the different tick stages were determined for 9 years. RESULTS: The DNA of the human pathogen R. conorii as well as R. helvetica, R. sp. IRS and R. bellii-like were found. Unexpectedly, the DNA of the highly pathogenic R. typhi and R. prowazekii and 4 other uncharacterized Rickettsia spp. related to the typhus group were also detected in I. ricinus. The presence of R. helvetica in fleas isolated from small rodents supported our hypothesis that cross-infection can occur under naturalconditions, since R. typhi/prowazekii and R. helvetica as well as their vectors share rodents as reservoir hosts. In one biotope, the infection rate with R. helvetica was ~66% for 9 years, and was comparable between larvae, nymphs, and adults. Larvae caught by flagging generally have not yet taken a blood meal from a vertebrate host. The simplest explanation for the comparable prevalence of R. helvetica between the defined tick stages is, that R. helvetica is vertically transmitted through the next generation with high efficiency. The DNA of R. helvetica was also present in whole blood from mice, deer and wild boar. CONCLUSION: Besides R. helvetica, unexpected rickettsiae are found in I. ricinus ticks. We propose that I. ricinus is a major reservoir host for R. helvetica, and that vertebrate hosts play important roles in the further geographical dispersion of rickettsiae.

Sprong, Hein; Wielinga, Pieter

2009-01-01

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Gene Sequence-Based Criteria for Identification of New Rickettsia Isolates and Description of Rickettsia heilongjiangensis sp. nov.  

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We propose genetic guidelines for the classification of rickettsial isolates at the genus, group, and species levels by using sequences of the 16S rRNA (rrs) gene and four protein-coding genes, the gltA, ompA, and ompB genes and gene D. To be classified as a member of the genus Rickettsia, an isolate should exhibit degrees of rrs and gltA homology with any of the 20 Rickettsia species studied of ?98.1 and ?86.5%, respectively. A member of the typhus group should fulfill at least two of th...

Fournier, Pierre-edouard; Dumler, J. Stephen; Greub, Gilbert; Zhang, Jianzhi; Wu, Yimin; Raoult, Didier

2003-01-01

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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 complexes were not. The R. prowazekii core played the major role in determining heparin sensitivity.

Aniskovitch, L. P.; Winkler, H. H.

1995-01-01

 
 
 
 
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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

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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 SciELO Brazil | Language: English 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 ci [...] clo 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. 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 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.

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.

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Experimentally infected human body lice (pediculus humanus humanus) as vectors of Rickettsia rickettsii and Rickettsia conorii in a rabbit model.  

Science.gov (United States)

The human body louse, the natural vector of Rickettsia prowazekii, is able to experimentally transmit the normally flea-borne rickettsia R. typhi, suggesting that the relationships between the body louse and rickettsiae are not specific. We used our experimental infection model to test the ability of body lice to transmit two prevalent tick-borne rickettsiae. Each of two rabbits was made bacteremic by injecting intravenously 2 x 10(6) plaque-forming units of either R. rickettsii or R. conorii. Four hundred body lice were infected by feeding on the bacteremic rabbit and were compared with 400 uninfected lice. Each louse group was fed once a day on a separate seronegative rabbit. The survival of infected lice was not different from that of uninfected controls. Lice remained infected for their lifespan, excreted R. rickettsii and R. conorii in their feces, but did not transmit the infection to their progeny. The nurse rabbit of uninfected lice remained asymptomatic and seronegative. Those rabbits used to feed infected lice developed bacteremia and seroconverted. Although the body louse is not a known vector of spotted fevers, it was able in our study to acquire, maintain, and transmit both R. rickettsii and R. conorii. PMID:16606977

Houhamdi, Linda; Raoult, Didier

2006-04-01

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Flying squirrel-associated Rickettsia prowazekii (epidemic typhus rickettsiae) characterized by a specific DNA fragment produced by restriction endonuclease digestion.  

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The DNA from flying squirrel-associated Rickettsia prowazekii was characterized by using a specific DNA fragment produced by digestion with the enzyme BamHI. The DNA fragment was cloned into a plasmid vector and used to readily distinguish between available human- and flying squirrel-associated R. prowazekii DNAs derived from crude cytoplasmic extracts.

Regnery, R. L.; Fu, Z. Y.; Spruill, C. L.

1986-01-01

105

Bartonella and Rickettsia in fleas and lice from mammals in South Carolina, U.S.A.  

Science.gov (United States)

Species in the genera Bartonella and Rickettsia are vector-borne pathogens of humans and domestic animals. The natural reservoirs and enzootic transmission cycles of these bacteria are poorly known in South Carolina. Thirteen species of lice and fleas were collected from urban animals and screened for the presence of Bartonella and Rickettsia by PCR amplification using genus-specific primers. Bartonella henselae was present in cat fleas (Ctenocephalides felis) from Virginia opossums (Didelphis virginiana) and a novel genotype of Bartonella was detected in Orchopeas howardi from an eastern gray squirrel (Sciurus carolinensis). We detected R. typhi and three novel genotypes Rickettsia in other species of fleas and lice. Rickettsia typhi, the causative agent of murine typhus, was detected in two pools of lice (Enderleinellus marmotae) from the woodchuck (Marmota monax). Cat fleas harbored one of two novel genotypes of Rickettsia. A third novel Rickettsia was detected in Orchopeas howardi from an eastern gray squirrel. PMID:16599169

Reeves, Will K; Nelder, Mark P; Korecki, James A

2005-12-01

106

Comparación de la Tomografía Axial Computarizada con el estudio anatomopatológico en el estadiaje ganglionar del cáncer de pulmón  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish PROPÓSITO: Evaluar la Sensibilidad, Especificidad, Valor predictivo positivo y Valor Predictivo Negativo de la Tomografia Axial Computarizada (TAC) en el estadiaje ganglionar del cáncer de pulmón. MATERIAL Y MÉTODOS: Se han analizado 30 pacientes diagnosticados de carcinoma pulmonar entre Mayo de 20 [...] 03 y Mayo de 2004. A todos los pacientes se les realizó una TAC torácica, valorando la afectación ganglionar mediastínica. A su vez, se les realizó o una mediastinoscopia o una resección pulmonar más linfadenectomía mediastínica, obteniendo así material para el estudio anatomo-patológico para confirmar o no la afectación ganglionar mediastínica y correlacionarla con los hallazgos de la TAC. RESULTADOS: Hemos obtenido una Sensibilidad del 72,2%, una Especificidad del 100%, un valor predictivo positivo del 100% y un valor predictivo negativo del 70,6% para la TAC, utilizando como "gold standar" el estudio anatomopatológico. CONCLUSIONES: La TAC torácica se considera una prueba de imagen de rutina en el diagnóstico del cáncer de pulmón; pero en muchos casos no es capaz de estadiar correctamente la afectación ganglionar mediastínica. Es en estos casos, donde es necesario realizar pruebas invasivas como la mediastinoscopia. Actualmente, la aparición de la PET permite estadiar mejor el tumor, ofreciendo mejor tratamiento a cada paciente, y en determinados casos evitar técnicas diagnósticas invasivas. Abstract in english PURPOSE: To analise the sensitivity, specificity, and positive and negative predictive values of the computerized axial tomography (CT) in nodal stages of lung carcinoma. MATERIAL AND METHODS: Thirty patients suffering from lung carcinoma were analysed between May 2003 and May 2004. CT screening of [...] the thorax was made to all the patients. Mediastinoscopy or lung resection samples plus systematic node dissection were performed, and the efficiency of CT analysed by comparing the obtained data with the histopathology results of nodal affection shown by mediastinoscopy and lymph node dissection. RESULTS: The sensitivity, specificity, and positive and negative predictive value of the computerized axial tomography (CT) for nodal staging involved in lung carcinoma were 72.2%, 100%, 100% and 70,6% respectively. CONCLUSIONS: CT of the thorax is considered a usual imaging technique in lung carcinoma diagnosis; but in some cases it does not focalise correctly the nodal staging involved in lung carcinoma. In theses cases, it is necessarry to perform invasive techniques such as mediastinoscopy. At present, positron emission tomography (PET) is the technique that better permits to focalise the tumor offering the best data for the therapy of each patient, and avoiding invasive diagnosis techniques.

M., López Mata; J., Valencia Julve; N., Bascón Santaló; C., Velilla Millán; R., Escó Barón; M., García Álvarez.

107

Analysis of hydrolytic products from choline-labeled host cell phospholipids during growth of Rickettsia prowazekii.  

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A phospholipase activity has been associated with the interaction of Rickettsia prowazekii with the surface of erythrocytes and competent host cells as well as during the growth of the rickettsiae within their host cells. Both fatty acid and lysophosphatides have been found in the interaction of rickettsiae with the surface of eucaryotic cells; this finding provided strong evidence for the activity of a phospholipase A. However, fatty acids, but not lysophosphatides, were found during the gro...

Winkler, H. H.; Day, L.; Daugherty, R.

1994-01-01

108

Ultrastructure of Rickettsia rickettsii Actin Tails and Localization of Cytoskeletal Proteins  

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Actin-based motility (ABM) is a mechanism for intercellular spread that is utilized by vaccinia virus and the invasive bacteria within the genera Rickettsia, Listeria, and Shigella. Within the Rickettsia, ABM is confined to members of the spotted fever group (SFG), such as Rickettsia rickettsii, the agent of Rocky Mountain spotted fever. Infection by each agent induces the polymerization of host cell actin to form the typical F (filamentous)-actin comet tail. Assembly of the actin tail propel...

Kirk, Levi S.; Hayes, Stanley F.; Heinzen, Robert A.

2000-01-01

109

Spotted fever group rickettsiae in Dermacentor variabilis from Cape Cod, Massachusetts.  

Science.gov (United States)

Spotted fever group (SFG) rickettsiae were identified by indirect immunofluorescent antibody tests in 1.1% of 6,956 specimens of Dermacentor variabilis collected on Cape Cod, Massachusetts. Forty-one of 45 rickettsial isolates were serotyped as Rickettsia montana, one as Rickettsia rickettsii, and three were unidentified. Studies of canines and humans with clinical evidence of spotted fever, and of healthy dogs with antibody to SFG rickettsiae, indicated that exposure of the canine population to R. montana was common but that R. montana was not involved in the etiology of spotted fever. PMID:6773430

Feng, W C; Murray, E S; Burgdorfer, W; Spielman, J M; Rosenberg, G; Dang, K; Smith, C; Spickert, C; Waner, J L

1980-07-01

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Structural Properties of Lipopolysaccharides from Rickettsia typhi and Rickettsia prowazekii and Their Chemical Similarity to the Lipopolysaccharide from Proteus vulgaris OX19 Used in the Weil-Felix Test  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The lipopolysaccharides (LPSs) isolated from typhus group (TG) rickettsiae Rickettsia typhi and Rickettsia prowazekii were characterized by chemical analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by silver staining. LPSs from two species of TG rickettsiae contained glucose, 3-deoxy-d-manno-octulosonic acid, glucosamine, quinovosamine, phosphate, and fatty acids (?-hydroxylmyristic acid and heneicosanoic acid) but not heptose. The O-polysaccharides ...

Amano, Ken-ichi; Williams, Jim C.; Dasch, Gregory A.

1998-01-01

111

Outbreaks of Rickettsia felis in Kenya and Senegal, 2010  

Centers for Disease Control (CDC) Podcasts

This podcast describes the outbreak of Rickettsia felis in Kenya between August 2006 and June 2008, and in rural Senegal from November 2008 through July 2009. CDC infectious disease pathologist Dr. Chris Paddock discusses what researchers learned about this flea-borne disease and how to prevent infection.  Created: 6/9/2010 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 6/24/2010.

2010-06-09

112

Comparative Genomics of Rickettsia prowazekii Madrid E and Breinl Strains  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rickettsia prowazekii, the causative agent of epidemic typhus, has been responsible for millions of human deaths. Madrid E is an attenuated strain of R. prowazekii, while Breinl is a virulent strain. The genomic DNA sequence of Madrid E has recently been published. To study the genomic variations between Madrid E (reference) and Breinl (test) DNAs, cohybridization experiments were performed on a DNA microarray containing all 834 protein-coding genes of Madrid E. Of the 834 genes assessed, 24 ...

Ge, Hong; Chuang, Yao-yu Eric; Zhao, Shuping; Tong, Min; Tsai, Mong-hsun; Temenak, Joseph J.; Richards, Allen L.; Ching, Wei-mei

2004-01-01

113

Radioiodination of an outer membrane protein in intact Rickettsia prowazekii.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Smith, D. K.; Winkler, H. H.

1980-01-01

114

Transposon Mutagenesis of the Obligate Intracellular Pathogen Rickettsia prowazekii  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Genetic analysis of Rickettsia prowazekii has been hindered by the lack of selectable markers and efficient mechanisms for generating rickettsial gene knockouts. We have addressed these problems by adapting a gene that codes for rifampin resistance for expression in R. prowazekii and by incorporating this selection into a transposon mutagenesis system suitable for generating rickettsial gene knockouts. The arr-2 gene codes for an enzyme that ADP-ribosylates rifampin, thereby destroying its an...

Qin, Aiping; Tucker, Aimee M.; Hines, Andria; Wood, David O.

2004-01-01

115

Establishment of a Replicating Plasmid in Rickettsia prowazekii  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rickettsia prowazekii, the causative agent of epidemic typhus, grows only within the cytosol of eukaryotic host cells. This obligate intracellular lifestyle has restricted the genetic analysis of this pathogen and critical tools, such as replicating plasmid vectors, have not been developed for this species. Although replicating plasmids have not been reported in R. prowazekii, the existence of well-characterized plasmids in several less pathogenic rickettsial species provides an opportunity t...

Wood, David O.; Hines, Andria; Tucker, Aimee M.; Woodard, Andrew; Driskell, Lonnie O.; Burkhardt, Nicole Y.; Kurtti, Timothy J.; Baldridge, Gerald D.; Munderloh, Ulrike G.

2012-01-01

116

mariner-Based Transposon Mutagenesis of Rickettsia prowazekii? †  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rickettsia prowazekii, the causative agent of epidemic typhus, is an obligate intracellular bacterium that grows directly within the cytoplasm of its host cell, unbounded by a vacuolar membrane. The obligate intracytoplasmic nature of rickettsial growth places severe restrictions on the genetic analysis of this distinctive human pathogen. In order to expand the repertoire of genetic tools available for the study of this pathogen, we have employed the versatile mariner-based, Himar1 transposon...

Liu, Zhi-mei; Tucker, Aimee M.; Driskell, Lonnie O.; Wood, David O.

2007-01-01

117

Genome Sequence of Rickettsia tamurae, a Recently Detected Human Pathogen in Japan  

Science.gov (United States)

Rickettsia tamurae is a member of the spotted fever group rickettsiae, which was reported in 2011 to cause human infections in Japan. We report the draft genome sequence of R. tamurae strain AT-1T, isolated from Amblyomma testudinarium ticks. PMID:25189579

Sentausa, Erwin; El Karkouri, Khalid; Michelle, Caroline; Caputo, Aurelia; Raoult, Didier

2014-01-01

118

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  

Directory of Open Access Journals (Sweden)

Full Text Available 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 revisión 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 ganglionarSquamous 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 metastasis 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

Pablo Ortega R

2008-04-01

119

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 SciELO Chile | Language: Spanish 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 facto [...] r pronóstico independiente del carcinoma escamoso de cabeza y cuello, pues la presencia de adenopatías metastásicas reduce la sobrevida casi en 50%. La siguiente revisión 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 s [...] quamous 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 metastasis 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

Pablo, Ortega R.

120

Characterization of the gene encoding the protective paracrystalline-surface-layer protein of Rickettsia prowazekii: presence of a truncated identical homolog in Rickettsia typhi.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The DNA sequence of the gene encoding the protective surface protein antigen (SPA) of Rickettsia prowazekii has been determined. The open reading frame of 4836 nucleotides with promoter and ribosome-binding site is present on a 10.1-kilobase EcoRI fragment. The encoded carboxyl terminus of the 169-kDa protein contains a potential transmembrane region and hydrophilic regions with many lysine and arginine residues potentially accessible to proteolytic cleavage. Because the rickettsia-derived SP...

Carl, M.; Dobson, M. E.; Ching, W. M.; Dasch, G. A.

1990-01-01

 
 
 
 
121

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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 human [...] o 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. Abstract in english 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 cas [...] e 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.

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.

122

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  

Directory of Open Access Journals (Sweden)

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

2011-11-01

123

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

124

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: English Abstract in spanish 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 an [...] aliza 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 Abstract in english 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 patient [...] s 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 =

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

2010-03-01

125

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: English Abstract in spanish 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 an [...] aliza 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 Abstract in english 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 patient [...] s 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 =

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

126

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

Directory of Open Access Journals (Sweden)

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.

Raoult Didier

2006-02-01

127

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.

Raoult Didier

2011-02-01

128

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

129

Radioiodination of an outer membrane protein in intact Rickettsia prowazekii  

Energy Technology Data Exchange (ETDEWEB)

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 /sup 125/I 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.

Smith, D.K.; Winkler, H.H.

1980-08-01

130

Nucleotide sequence of the Rickettsia prowazekii citrate synthase gene.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Rickettsia prowazekii citrate synthase (gltA) gene, previously cloned in Escherichia coli, was localized to a 2.0-kilobase chromosomal fragment. DNA sequence analysis of a portion of this fragment revealed an open reading frame of 1,308 base pairs that encodes a protein of 435 amino acids with a molecular weight of 49,171. This translation product is comparable in size to both the E. coli and pig heart citrate synthase monomers and to the protein synthesized in E. coli minicells containin...

Wood, D. O.; Williamson, L. R.; Winkler, H. H.; Krause, D. C.

1987-01-01

131

Transcriptional regulation in the obligate intracytoplasmic bacterium Rickettsia prowazekii.  

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Transcriptional regulation was demonstrated in Rickettsia prowazekii, an obligate intracytoplasmic bacterium. The level of citrate synthase (gltA) mRNA II, from promoter P2, was greater in the total RNA isolated from heavily infected L929 cells than in moderately infected L929 cells; conversely, the level of ATP/ADP translocase (tlc) mRNA was greater in moderately infected cells. The level of gltA mRNA I, from promoter P1, did not change under these conditions. The chemical half-lives of gltA...

Cai, J.; Winkler, H. H.

1996-01-01

132

Characterization of the symbiont Rickettsia in the mirid bug Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae).  

Science.gov (United States)

Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) is an omnivorous insect used for biological control. Augmentative release and conservation of N. tenuis have been used for pest control in tomato crops. Intracellular bacterial symbionts of arthropods are common in nature and have diverse effects on their hosts; in some cases they can dramatically affect biological control. Fingerprinting methods showed that the symbiotic complex associated with N. tenuis includes Wolbachia and Rickettsia. Rickettsia of N. tenuis was further characterized by sequencing the 16S rRNA and gltA bacterial genes, measuring its amount in different developmental stages of the insect by real-time polymerase chain reaction, and localizing the bacteria in the insect's body by fluorescence in situ hybridization. The Rickettsia in N. tenuis exhibited 99 and 96% similarity of both sequenced genes to Rickettsia bellii and Rickettsia reported from Bemisia tabaci, respectively. The highest amount of Rickettsia was measured in the 5th instar and adult, and the symbionts could be detected in the host gut and ovaries. Although the role played by Rickettsia in the biology of N. tenuis is currently unknown, their high amount in the adults and localization in the gut suggest that they may have a nutritional role in this insect. PMID:25062354

Caspi-Fluger, A; Inbar, M; Steinberg, S; Friedmann, Y; Freund, M; Mozes-Daube, N; Zchori-Fein, E

2014-12-01

133

Genotypic identification of an undescribed spotted fever group Rickettsia in Ixodes ricinus from southwestern Spain  

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An undescribed rickettsia was directly analyzed with specific rickettsial molecular biology tools on Ixodes ricinus L. collected in different localities of the province of Cadiz (southwestern Spain). On the basis of the results of the citrate synthase (glta) gene, 190 kD-outer membrane protein (rOmpA) gene, and 16S ribosomal RNA (16S rRNA) gene partial sequence data, it was found that this rickettsia is sufficiently genetically distinct from other Rickettsia to be considered a distinct taxono...

Ma?rquez, F. J.; Muniain, M. A.; Soriguer, Ramo?n C.; Izquierdo, Guillermo; Rodri?guez-ban?o, Jesu?s; Borobio, M. Victoria

1998-01-01

134

Borrelia, Rickettsia, and Ehrlichia Species in Bat Ticks, France, 2010  

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Argas vespertilionis, an argasid tick associated with bats and bat habitats in Europe, Africa, and Asia has been reported to bite humans; however, studies investigating the presence of vector-borne pathogens in these ticks are lacking. Using molecular tools, we tested 5 A. vespertilionis ticks collected in 2010 from the floor of a bat-infested attic in southwestern France that had been converted into bedrooms. Rickettsia sp. AvBat, a new genotype of spotted fever group rickettsiae, was detected and cultivated from 3 of the 5 ticks. A new species of the Ehrlichia canis group, Ehrlichia sp. AvBat, was also detected in 3 ticks. Four ticks were infected with Borrelia sp. CPB1, a relapsing fever agent of the Borrelia group that caused fatal borreliosis in a bat in the United Kingdom. Further studies are needed to characterize these new agents and determine if the A. vespertilionis tick is a vector and/or reservoir of these agents. PMID:23171714

Socolovschi, Cristina; Kernif, Tahar; Raoult, Didier

2012-01-01

135

Establishment of a replicating plasmid in Rickettsia prowazekii.  

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Rickettsia prowazekii, the causative agent of epidemic typhus, grows only within the cytosol of eukaryotic host cells. This obligate intracellular lifestyle has restricted the genetic analysis of this pathogen and critical tools, such as replicating plasmid vectors, have not been developed for this species. Although replicating plasmids have not been reported in R. prowazekii, the existence of well-characterized plasmids in several less pathogenic rickettsial species provides an opportunity to expand the genetic systems available for the study of this human pathogen. Competent R. prowazekii were transformed with pRAM18dRGA, a 10.3 kb vector derived from pRAM18 of R. amblyommii. A plasmid-containing population of R. prowazekii was obtained following growth under antibiotic selection, and the rickettsial plasmid was maintained extrachromosomally throughout multiple passages. The transformant population exhibited a generation time comparable to that of the wild type strain with a copy number of approximately 1 plasmid per rickettsia. These results demonstrate for the first time that a plasmid can be maintained in R. prowazekii, providing an important genetic tool for the study of this obligate intracellular pathogen. PMID:22529927

Wood, David O; Hines, Andria; Tucker, Aimee M; Woodard, Andrew; Driskell, Lonnie O; Burkhardt, Nicole Y; Kurtti, Timothy J; Baldridge, Gerald D; Munderloh, Ulrike G

2012-01-01

136

Quantitative study of Rickettsia massiliae in Rhipicephalus sanguineus organs.  

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Rickettsia massiliae, belonging to the spotted fever group of Rickettsia, is a human pathogen causing a similar course of disease to that caused by R. conorii, the originally recognized etiologic agent of Mediterranean spotted fever. In view of this similarity, we performed an ultrastructural study of R. massiliae in organs of Rhipicephalus sanguineus ticks, in order to advance knowledge of the complex dynamics at the tick-pathogen interface in rickettsioses. Adult R. massiliae-infected Rh. sanguineus ticks were fed on uninfected Hartley strain guinea pigs, and five females were collected daily throughout their feeding period up to day 6, and analyzed by quantitative real-time PCR and electron microscopy. An increase in rickettsial content was observed in the salivary glands, particularly in the first two days of feeding, and a plateau was observed between days 3 and 6. Rickettsial organisms were observed in all tick organs analyzed, in higher numbers in the fed state, and statistically significant differences were observed in measurements of the periplasmic layer of R. massiliae in salivary glands of fed and unfed Rh. sanguineus ticks, with increased thickness in the former case. This study provides insight into the interface between R. massiliae and Rh. sanguineus ticks, highlighting the need for analysis of R. massiliae to fully ascertain its place as an important pathogenic agent of a spotted fever rickettsiosis. PMID:25108779

Milhano, Natacha; Popov, Vsevolod; Vilhena, Manuela; Bouyer, Donald H; de Sousa, Rita; Walker, David H

2014-10-01

137

Comparação entre tomografia computadorizada e mediastinoscopia na avaliação do envolvimento ganglionar mediastínico no carcinoma brônquico não de pequenas células / Comparison between computed tomography and mediastinoscopy in the assessment of mediastinal nodal involvement in non-small cell bronchial carcinoma  

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: Avaliar o rendimento da tomografia computadorizada torácica, em relação à mediastinoscopia, na detecção de metástases ganglionares mediastinais em pacientes portadores de carcinoma brônquico analisando o rendimento dessa e identificando as regiões mais problemáticas. MATERIAIS E MÉTODOS: A [...] nalisamos 195 pacientes portadores de carcinoma brônquico, buscando-se comparar os achados entre tomografia computadorizada torácica e mediastinoscopia com biópsia. RESULTADOS: Em relação às metástases nodais mediastinais, 33,9% tinham doença metastática ganglionar peribrônquica e/ou hilar ipsilateral, 46,1% possuíam metástases mediastinais ipsilaterais e/ou subcarinais e 20% apresentavam doença metastática mediastinal e/ou hilar contralateral, escalênica ou supraclavicular. As regiões com melhores valores de sensibilidade foram traqueobrônquica direita, paratraqueal direita alta e paratraqueal esquerda alta. As regiões nodais com melhores resultados de especificidade foram paratraqueal esquerda alta, paratraqueal direita alta e regiões traqueobrônquicas. CONCLUSÃO: A tomografia computadorizada torácica mostrou-se importante ferramenta diagnóstica na detecção de anormalidades em gânglios mediastinais; entretanto, a natureza neoplásica desses gânglios deve ser conferida por mediastinoscopia, ou até mesmo por toracotomia, a fim de que a correta decisão quanto ao tratamento possa ser tomada. Abstract in english OBJECTIVE: To evaluate the yielding of chest computed tomography in comparison with mediastinoscopy for detection of mediastinal nodal metastases in patients with bronchial carcinoma, and identifying the most problematic regions. MATERIALS AND METHODS: We have analyzed 195 patients with bronchial ca [...] rcinoma, comparing the findings of chest computed tomography and mediastinoscopy with biopsy. RESULTS: As regards mediastinal nodal metastasis, 33.9% of patients presented peribronchial and/or ipsilateral hilar nodal metastases, 46.1% ipsilateral and/or subcarinal mediastinal metastases, and 20% contralateral mediastinal and/or hilar, scalenic or supraclavicular metastatic disease. Higher sensitivity values were found in the following regions: right tracheobronchial, right upper paratracheal, and left upper paratracheal. Higher specificity values were found in the following nodal regions: left upper paratracheal, right upper paratracheal and tracheobronchial. CONCLUSION: Chest computed tomography has shown to be an important diagnostic tool for detection of mediastinal lymph nodes abnormalities. However, the neoplastic nature of such mediastinal nodes should be confirmed by means of mediastinoscopy or even thoracotomy, aiming at making the correct decision regarding the treatment of patients with non-small cell lung cancer.

Décio Valente, Renck; Daniel Brito de, Araújo; Nilton Haertel, Gomes; Rodrigo, Mendonça.

138

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].

Audic Stéphane

2009-04-01

139

Development of a duplex real-time PCR for the detection of Rickettsia spp. and typhus group rickettsia in clinical samples.  

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Molecular diagnosis using real-time polymerase chain reaction (PCR) may allow earlier diagnosis of rickettsiosis. We developed a duplex real-time PCR that amplifies (1) DNA of any rickettsial species and (2) DNA of both typhus group rickettsia, that is, Rickettsia prowazekii and Rickettsia typhi. Primers and probes were selected to amplify a segment of the 16S rRNA gene of Rickettsia spp. for the pan-rickettsial PCR and the citrate synthase gene (gltA) for the typhus group rickettsia PCR. Analytical sensitivity was 10 copies of control plasmid DNA per reaction. No cross-amplification was observed when testing human DNA and 22 pathogens or skin commensals. Real-time PCR was applied to 16 clinical samples. Rickettsial DNA was detected in the skin biopsies of three patients. In one patient with severe murine typhus, the typhus group PCR was positive in a skin biopsy from a petechial lesion and seroconversion was later documented. The two other patients with negative typhus group PCR suffered from Mediterranean and African spotted fever, respectively; in both cases, skin biopsy was performed on the eschar. Our duplex real-time PCR showed a good analytical sensitivity and specificity, allowing early diagnosis of rickettsiosis among three patients, and recognition of typhus in one of them. PMID:22098502

Giulieri, Stefano; Jaton, Katia; Cometta, Alain; Trellu, Laurence T; Greub, Gilbert

2012-02-01

140

Detection of rickettsia parkeri from within Piura, Peru, and the first reported presence of Candidatus rickettsia andeanae in the tick Rhipicephalus sanguineus.  

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Domestic farm animals (n=145) were sampled for the presence of ectoparasites in northwestern Peru during March, 2008. Ninety domestic animals (62%) were positive for the presence of an ectoparasite(s) and produced a total collection of the following: 728 ticks [Amblyomma maculatum, Anocentor nitens, Rhipicephalus (Boophilus) microplus, Rhipicephalus sanguineus, and Otobius megnini], 12 lice (Haematopinus suis), and 3 fleas (Ctenocephalides felis). A Rickettsia genus-specific qPCR assay was performed on nucleic acid preparations of the collected ectoparasites that resulted in 5% (37/743, 35 ticks and 2 fleas) of the ectoparasites positive for the presence of Rickettsia. DNA from the positive individual ticks was tested with 2 other qPCR assays for the presence of the ompB gene in Candidatus Rickettsia andeanae or Rickettsia parkeri. Candidatus R. andeanae was found in 25 A. maculatum ticks and in two Rh. sanguineus ticks, whereas R. parkeri was detected in 6 A. maculatum ticks. Two A. maculatum were co-infected with both Candidatus R. andeanae and R. parkeri. Rickettsia felis was detected in 2 fleas, Ctenocephalides felis, by multilocus sequence typing of the 17-kD antigen and ompA genes. These findings expand the geographic range of R. parkeri to include Peru as well as expand the natural arthropod vector of Candidatus R. andeanae to include Rhipicephalus sanguineus. PMID:23488453

Flores-Mendoza, Carmen; Florin, David; Felices, Vidal; Pozo, Edwar J; Graf, Paul C F; Burrus, Roxanne G; Richards, Allen L

2013-07-01

 
 
 
 
141

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

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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.

Winkler, H.H.; Miller, E.T.

1982-10-01

142

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

143

Rickettsia Sca2 is a bacterial formin-like mediator of actin-based motility  

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Diverse intracellular pathogens subvert the host actin polymerization machinery to drive movement within and between cells during infection. Rickettsia in the spotted fever group (SFG) are Gram-negative, obligate intracellular bacterial pathogens that undergo actin-based motility and assemble distinctive ‘comet tails’ that consist of long, unbranched actin filaments1,2. Despite this distinct organization, it was proposed that actin in Rickettsia comet tails is nucleated by the host Arp2/3...

Haglund, Cat M.; Choe, Julie E.; Skau, Colleen T.; Kovar, David R.; Welch, Matthew D.

2010-01-01

144

Comparison of properties of virulent, avirulent, and interferon-resistant Rickettsia prowazekii strains.  

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Several properties of virulent, avirulent, and interferon-resistant Rickettsia prowazekii strains were compared. All of the interferon-resistant rickettsial strains (which were derived from the avirulent Madrid E strain) resembled the virulent Breinl strain in that they grew well in untreated mouse macrophagelike RAW264.7 cells. In contrast, the avirulent Madrid E strain grew poorly in untreated RAW264.7 cells. Pretreatment of interferon-resistant rickettsiae or R. prowazekii Breinl with anti...

Turco, J.; Winkler, H. H.

1991-01-01

145

Cloned mouse interferon-gamma inhibits the growth of Rickettsia prowazekii in cultured mouse fibroblasts  

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The effect of treating cultured mouse fibroblasts (L929 cells) with cloned mouse interferon-gamma on the growth of Rickettsia prowazekii within the fibroblasts was studied. Within 48 h after infection, rickettsiae were cleared from a substantial proportion of the initially infected cells and rickettsial growth was inhibited in those cells that remained infected, when L929 cells were treated with cloned mouse interferon-gamma both before and after infection. When L929 cells were treated with c...

1983-01-01

146

Inhibition of the growth of Rickettsia prowazekii in cultured fibroblasts by lymphokines  

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The effect of lymphokine treatment of mouse and human fibroblast cell lines on the growth of Rickettsia prowazekii within the fibroblasts was studied. Treatment of mouse L929 cells with concanavalin A- or antigen- induced mouse lymphokines both before and after infection with R. prowazekii led to clearance of the rickettsiae from a substantial proportion of the cells and suppression of rickettsial growth in those cells which remained infected. Similar but less dramatic anti- rickettsial effec...

1983-01-01

147

Interactions between Rickettsia prowazekii and rabbit polymorphonuclear leukocytes: rickettsiacidal and leukotoxic activities.  

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Rickettsia prowazekii was assessed for in vitro susceptibility to phagocytosis by rabbit polymorphonuclear leukocytes. [alpha-32P]adenosine triphosphate-labeled rickettsiae were used to determine phagocytosis and adsorption quantitatively. R. prowazekii was less susceptible to phagocytosis than were Escherichia coli and Neisseria gonorrhoeae. Although R. prowazekii was similar to E. coli in susceptibility to superoxide and activated halide, few phagocytized rickettsial cells were inactivated ...

Walker, T. S.; Winkler, H. H.

1981-01-01

148

Purification and partial characterization of the DNA-dependent RNA polymerase from Rickettsia prowazekii.  

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The DNA-dependent RNA polymerase was purified from Rickettsia prowazekii, an obligate intracellular bacterial parasite. Because of limitation of available rickettsiae, the classical methods for isolation of the enzyme from other procaryotes were modified to purify RNA polymerase from small quantities of cells (25 mg of protein). The subunit composition of the rickettsial RNA polymerase was typical of a eubacterial RNA polymerase. R. prowazekii had beta' (148,000 daltons), beta (142,000 dalton...

Ding, H. F.; Winkler, H. H.

1990-01-01

149

Infection of Amblyomma ovale by Rickettsia sp. strain Atlantic rainforest, Colombia.  

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Our goal was to understand rickettsial spotted fevers' circulation in areas of previous outbreaks reported from 2006 to 2008 in Colombia. We herein present molecular identification and isolation of Rickettsia sp. Atlantic rainforest strain from Amblyomma ovale ticks, a strain shown to be pathogenic to humans. Infected ticks were found on dogs and a rodent in Antioquia and Córdoba Provinces. This is the first report of this rickettsia outside Brazil, which expands its known range considerably. PMID:25090976

Londoño, Andrés F; Díaz, Francisco J; Valbuena, Gustavo; Gazi, Michal; Labruna, Marcelo B; Hidalgo, Marylin; Mattar, Salim; Contreras, Verónica; Rodas, Juan D

2014-10-01

150

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

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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 /sup 51/Cr-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.

Carl, M.; Robbins, F.; Hartzman, R.J.; Dasch, G.A.

1987-12-15

151

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

152

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

Science.gov (United States)

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. PMID:16672513

Gottlieb, Yuval; Ghanim, Murad; Chiel, Elad; Gerling, Dan; Portnoy, Vitaly; Steinberg, Shimon; Tzuri, Galil; Horowitz, A Rami; Belausov, Eduard; Mozes-Daube, Neta; Kontsedalov, Svetlana; Gershon, Moshe; Gal, Shunit; Katzir, Nurit; Zchori-Fein, Einat

2006-05-01

153

Identification and characterization of epitopes on the 120-kilodalton surface protein antigen of Rickettsia prowazekii with synthetic peptides.  

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The 120-kDa surface protein antigens (SPAs) of typhus rickettsiae are highly immunogenic and have been shown to be responsible for the species-specific serological reactions of the typhus group rickettsiae. To study the immunochemistry of these proteins, overlapping decapeptides encompassing the whole protein were synthesized on derivatized polyethylene pins. A modified enzyme-linked immunosorbent assay was used to identify epitopes recognized by rabbit hyperimmune antisera to Rickettsia prow...

Ching, W. M.; Wang, H.; Jan, B.; Dasch, G. A.

1996-01-01

154

Heterogeneity of CD4-positive human T-cell clones which recognize the surface protein antigen of Rickettsia typhi.  

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Immunity to the typhus group of rickettsiae is largely dependent on the effector function of several classes of T lymphocytes, including those which produce gamma interferon. Since the surface protein antigen (SPA) derived from typhus group rickettsiae has been shown to be an effective immunogen in animal models, human T-cell clones specific for the SPA of Rickettsia typhi were isolated and tested for their antigenic specificity, as well as for their ability to produce gamma interferon. Eight...

Carl, M.; Vaidya, S.; Robbins, F. M.; Ching, W. M.; Hartzman, R. J.; Dasch, G. A.

1989-01-01

155

Prevalence of Rickettsia infection in dogs from the urban and rural areas of Monte Negro municipality, western Amazon, Brazil.  

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The present study evaluated the rickettsial infection among dogs living in the rural and urban areas of Monte Negro, state of Rondônia, western Brazilian Amazon. Canine sera were tested by the indirect immunofluorescence assay (IFA) using six rickettsial antigens: Rickettsia bellii, Rickettsia amblyommii, Rickettsia rhipicephali, Rickettsia rickettsii, Rickettsia parkeri, and Rickettsia felis. While the first three Rickettsia species are known to occur in the study site, the latter three species are known to occur in southeastern Brazil. For each serum, end point titer reacting with each Rickettsia antigen was determined. Serum showing for a Rickettsia species titer at least fourfold higher than that observed for any other Ricketttsia species was considered homologous to the first Rickettsia species or to a very closely related genotype. A total of 164 rural and 153 urban dogs were tested. Overall, 19 (11.6%) and 6 (3.9%) dogs from rural and urban areas, respectively, reacted positively to at least one Rickettsia species. In the rural area, three sera showed titers to R. parkeri at least four-fold higher than any of the other five antigens. These sera were considered to be homologous to R. parkeri or a very closely related genotype. Using the same criteria, two rural sera were considered homologous to R. amblyommii, two other rural sera to R. rhipicephali, and one urban serum to R. parkeri. Because dogs living in the rural area of Monte Negro are commonly infested by the same tick species infesting humans, they indeed serve as sentinels for human rickettsial diseases. Thus, humans living in Monte Negro are likely to be infected by at least three Rickettsia species: R. parkeri, R. amblyommii, and R. rhipicephali. While R. parkeri is a known human pathogen, further studies are required to verify the potential role of R. amblyommii and R. rhipicephali as human pathogens. PMID:17627445

Labruna, Marcelo B; Horta, Maurício C; Aguiar, Daniel M; Cavalcante, Guacyara T; Pinter, Adriano; Gennari, Solange M; Camargo, Luis Marcelo A

2007-01-01

156

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.

John Stephen Dumler

2011-10-01

157

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

2011-12-01

158

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  

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Full Text Available SciELO Colombia | Language: Spanish 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 domé [...] sticos 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 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 anima [...] ls 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-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.

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

159

Multimethylation of Rickettsia OmpB catalyzed by lysine methyltransferases.  

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Methylation of rickettsial OmpB (outer membrane protein B) has been implicated in bacterial virulence. Rickettsial methyltransferases RP789 and RP027-028 are the first biochemically characterized methyltransferases to catalyze methylation of outer membrane protein (OMP). Methylation in OMP remains poorly understood. Using semiquantitative integrated liquid chromatography-tandem mass spectroscopy, we characterize methylation of (i) recombinantly expressed fragments of Rickettsia typhi OmpB exposed in vitro to trimethyltransferases of Rickettsia prowazekii RP027-028 and of R. typhi RT0101 and to monomethyltransferases of R. prowazekii RP789 and of R. typhi RT0776, and (ii) native OmpBs purified from R. typhi and R. prowazekii strains Breinl, RP22, and Madrid E. We found that in vitro trimethylation occurs at relatively specific locations in OmpB with consensus motifs, KX(G/A/V/I)N and KT(I/L/F), whereas monomethylation is pervasive throughout OmpB. Native OmpB from virulent R. typhi contains mono- and trimethyllysines at locations well correlated with methylation in recombinant OmpB catalyzed by methyltransferases in vitro. Native OmpBs from highly virulent R. prowazekii strains Breinl and RP22 contain multiple clusters of trimethyllysine in contrast to a single cluster in OmpB from mildly virulent R. typhi. Furthermore, OmpB from the avirulent strain Madrid E contains mostly monomethyllysine and no trimethyllysine. The native OmpB from Madrid E was minimally trimethylated by RT0101 or RP027-028, consistent with a processive mechanism of trimethylation. This study provides the first in-depth characterization of methylation of an OMP at the molecular level and may lead to uncovering the link between OmpB methylation and rickettsial virulence. PMID:24497633

Abeykoon, Amila; Wang, Guanghui; Chao, Chien-Chung; Chock, P Boon; Gucek, Marjan; Ching, Wei-Mei; Yang, David C H

2014-03-14

160

Sequence and Expression Analysis of the ompA Gene of Rickettsia peacockii, an Endosymbiont of the Rocky Mountain Wood Tick, Dermacentor andersoni  

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The transmission dynamics of Rocky Mountain spotted fever in Montana appears to be regulated by Rickettsia peacockii, a tick symbiotic rickettsia that interferes with transmission of virulent Rickettsia rickettsii. To elucidate the molecular relationships between the two rickettsiae and glean information on how to possibly exploit this interference phenomenon, we studied a major rickettsial outer membrane protein gene, ompA, presumed to be involved in infection and pathogenesis of spotted fev...

Baldridge, Gerald D.; Burkhardt, Nicole Y.; Simser, Jason A.; Kurtti, Timothy J.; Munderloh, Ulrike G.

2004-01-01

 
 
 
 
161

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.

Raoult Didier

2005-03-01

162

The rickettsia surface cell antigen 4 applies mimicry to bind to and activate vinculin.  

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Pathogenic Rickettsia species cause high morbidity and mortality, especially R. prowazekii, the causative agent of typhus. Like many intracellular pathogens, Rickettsia exploit the cytoskeleton to enter and spread within the host cell. Here we report that the cell surface antigen sca4 of Rickettsia co-localizes with vinculin in cells at sites of focal adhesions in sca4-transfected cells and that sca4 binds to and activates vinculin through two vinculin binding sites (VBSs) that are conserved across all Rickettsia. Remarkably, this occurs through molecular mimicry of the vinculin-talin interaction that is also seen with the IpaA invasin of the intracellular pathogen Shigella, where binding of these VBSs to the vinculin seven-helix bundle head domain (Vh1) displaces intramolecular interactions with the vinculin tail domain that normally clamp vinculin in an inactive state. Finally, the vinculin·sca4-VBS crystal structures reveal that vinculin adopts a new conformation when bound to the C-terminal VBS of sca4. Collectively, our data define the mechanism by which sca4 activates vinculin and interacts with the actin cytoskeleton, and they suggest important roles for vinculin in Rickettsia pathogenesis. PMID:21841197

Park, HaJeung; Lee, Jun Hyuck; Gouin, Edith; Cossart, Pascale; Izard, Tina

2011-10-01

163

Differential proteomic analysis of Rickettsia prowazekii propagated in diverse host backgrounds.  

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The obligate intracellular growth of Rickettsia prowazekii places severe restrictions on the analysis of rickettsial gene expression. With a small genome, predicted to code for 835 proteins, identifying which proteins are differentially expressed in rickettsiae that are isolated from different hosts or that vary in virulence is critical to an understanding of rickettsial pathogenicity. We employed a liquid chromatography (LC)-linear trap quadrupole (LTQ)-Orbitrap mass spectrometer for simultaneous acquisition of quantitative mass spectrometry (MS)-only data and tandem mass spectrometry (MS-MS) sequence data. With the use of a combination of commercially available algorithms and in-house software, quantitative MS-only data and comprehensive peptide coverage generated from MS-MS were integrated, resulting in the assignment of peptide identities with intensity values, allowing for the differential comparison of complex protein samples. With the use of these protocols, it was possible to directly compare protein abundance and analyze changes in the total proteome profile of R. prowazekii grown in different host backgrounds. Total protein extracted from rickettsiae grown in murine, tick, and insect cell lines or hen egg yolk sacs was analyzed. Here, we report the fold changes, including an upregulation of shock-related proteins, in rickettsiae cultivated in tissue culture compared to the level for rickettsiae harvested from hen yolk sacs. The ability to directly compare, in a complex sample, differential rickettsial protein expression provides a snapshot of host-specific proteomic profiles that will help to identify proteins important in intracellular growth and virulence. PMID:21642410

Tucker, Aimee M; Driskell, Lonnie O; Pannell, Lewis K; Wood, David O

2011-07-01

164

Isolation of the Rickettsial Agent Genetically Similar to Candidatus Rickettsia kotlanii, from Haemaphysalis megaspinosa in Japan.  

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Abstract Two rickettsial isolates, HM-1 and HM-2, were isolated from Haemaphysalis megaspinosa collected in Japan in 2006 and 2011, respectively. The isolates were analyzed by DNA sequences of the outer membrane protein A gene, the outer membrane protein B gene, the citrate synthase gene, the genus Rickettsia-specific outer membrane protein 17-kDa gene, the 16S ribosome RNA gene, and the PS120 protein gene ("geneD"). HM-1 was identified as Rickettsia tamurae. HM-2 matched most closely with 'Candidatus Rickettsia kotlanii' DNA, which has only been reported from H. concinna in Hungary. This is the first report of isolation in Japan of the agent genetically similar to 'Candidatus R. kotlanii,' which belongs phylogenetically to the spotted fever group Rickettsia. Our study shows the possibility that 'Candidatus R. kotlanii' can be carried by at least two tick species. Furthermore, because the Rickettsia sp. has been found two distant countries, Hungary and Japan, it has potential for wider distribution. PMID:25229707

Andoh, Masako; Ogasawara, Yumiko; Sakata, Akiko; Ito, Takuya; Fujita, Hiromi; Kawabata, Hiroki; Ando, Shuji

2014-09-01

165

Identification of rickettsiae from wild rats and cat fleas in Malaysia.  

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Rickettsioses are emerging zoonotic diseases reported worldwide. In spite of the serological evidence of spotted fever group rickettsioses in febrile patients in Malaysia, limited studies have been conducted to identify the animal reservoirs and vectors of rickettsioses. This study investigated the presence of rickettsiae in the tissue homogenates of 95 wild rats and 589 animal ectoparasites. Using PCR assays targeting the citrate synthase gene (gltA), rickettsial DNA was detected in the tissue homogenates of 13 (13.7%) wild rats. Sequence analysis of the gltA amplicons showed 98.6-100% similarity with those of Rickettsia honei/R. conorii/R. raoultii (Rickettsiales: Rickettsiaceae). Sequence analysis of outer membrane protein A gene (ompA) identified Rickettsia sp. TCM1 strain from two rats. No rickettsia was detected from Laelaps mites, Rhipicephalus sanguineus and Haemaphysalis bispinosa ticks, and Felicola subrostratus lice in this study. R. felis was identified from 32.2% of 177 Ctenocephalides felis fleas. Sequence analysis of the gltA amplicons revealed two genotypes of R. felis (Rf31 and RF2125) in the fleas. As wild rats and cat fleas play an important role in the enzoonotic maintenance of rickettsiae, control of rodent and flea populations may be able to reduce transmission of rickettsioses in the local setting. PMID:25171613

Tay, S T; Mokhtar, A S; Low, K C; Mohd Zain, S N; Jeffery, J; Abdul Aziz, N; Kho, K L

2014-08-01

166

Spotted fever rickettsiae in ticks from the northern Sinai Governate, Egypt.  

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A field study was initiated in 1988 to investigate whether spotted fever group rickettsiae occur in geographic areas in Egypt that are adjacent to an area in the southern Israeli Negev that has a defined focus of spotted fever disease. Ticks were collected from dogs, sheep, and camels at four study sites in the northern Sinai. Tick hemolymph was processed for rickettsial detection by staining with fluorescein isothiocyanate-conjugated antibody to Rickettsia rickettsii. Of the 442 hemolymphs examined, 15 contained immunofluorescent rickettsiae. Eight hemolymph test-positive (HT+) ticks were Rhipicephalus sanguineus removed from dogs; the other HT+ ticks comprised three Hyalomma species, H. anatolicum, H. impeltatum, and H. dromedarii. Both HT+ and HT- ticks were tested for rickettsial DNA using the polymerase chain reaction (PCR). Eight of 10 HT+ field-collected ticks were PCR positive (PCR+). All laboratory colony R. rickettsii-infected ticks were PCR+. No HT- ticks from field or laboratory isolates were PCR+. PMID:1599048

Lange, J V; el Dessouky, A G; Manor, E; Merdan, A I; Azad, A F

1992-05-01

167

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

Science.gov (United States)

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. PMID:23164496

Kernif, Tahar; Djerbouh, Amel; Mediannikov, Oleg; Ayach, Bouhous; Rolain, Jean-Marc; Raoult, Didier; Parola, Philippe; Bitam, Idir

2012-12-01

168

Mariner-based transposon mutagenesis of Rickettsia prowazekii.  

Science.gov (United States)

Rickettsia prowazekii, the causative agent of epidemic typhus, is an obligate intracellular bacterium that grows directly within the cytoplasm of its host cell, unbounded by a vacuolar membrane. The obligate intracytoplasmic nature of rickettsial growth places severe restrictions on the genetic analysis of this distinctive human pathogen. In order to expand the repertoire of genetic tools available for the study of this pathogen, we have employed the versatile mariner-based, Himar1 transposon system to generate insertional mutants of R. prowazekii. A transposon containing the R. prowazekii arr-2 rifampin resistance gene and a gene coding for a green fluorescent protein (GFP(UV)) was constructed and placed on a plasmid expressing the Himar1 transposase. Electroporation of this plasmid into R. prowazekii resulted in numerous transpositions into the rickettsial genome. Transposon insertion sites were identified by rescue cloning, followed by DNA sequencing. Random transpositions integrating at TA sites in both gene coding and intergenic regions were identified. Individual rickettsial clones were isolated by the limiting-dilution technique. Using both fixed and live-cell techniques, R. prowazekii transformants expressing GFP(UV) were easily visible by fluorescence microscopy. Thus, a mariner-based system provides an additional mechanism for generating rickettsial mutants that can be screened using GFP(UV) fluorescence. PMID:17720821

Liu, Zhi-Mei; Tucker, Aimee M; Driskell, Lonnie O; Wood, David O

2007-10-01

169

Thoracic radiographic findings in dogs infected with Rickettsia rickettsii  

International Nuclear Information System (INIS)

Sixteen beagle dogs were injected intradermally with Rickettsia rickettsii. The dogs were divided into four groups (n = 4): 1) infected, non-treated control; 2) infected, treated with doxycycline; 3) infected, treated with doxycycline and an anti-inflammatory dose of corticosteroid; and 4) infected, treated with doxycycline and an immunosuppressive dose of corticosteroid. Thoracic radiographs were made and ocular fluorescein angiography was performed on days 6, 10, 17 post-inoculation. A mild interstitial lung opacity was noted in 4/16 dogs on day 6, 5/16 on day 10 and 3/16 on day 17 post-inoculation. Increased retinal vascular permeability was noted in 8/16 dogs on day 6, 3/16 on day 10 and 1/16 on day 17 post-inoculation. Correlation between the presence of radiographic and retinal lesions was not significant (p = 0.08). Eleven, naturally infected, dogs with thoracic radiographs and a final diagnosis of RMSF were also evaluated. Four of the 11 dogs had an unstructured interstitial pattern. Dogs with acute, experimentally-infected or naturally-occurring RMSF may have subtle pulmonary changes characterized by an unstructured interstitial pattern

170

Rickettsia bellii in ticks Amblyomma varium Koch, 1844, from birds in Peru.  

Science.gov (United States)

Amazonian birds were caught and examined for the presence of ectoparasites in the Allpahuayo Mishana National Reserve near Iquitos, Peru, from 13 to 16 August 2011. A total of 40 birds representing 16 species were examined. Two birds (5%) were infested with 2 larvae of Amblyomma varium Koch, 1844, and one nymph of A. calcaratum Neumann, 1899. The 2 larvae of A. varium were infected with Rickettsia bellii. This is the first report of R. bellii in A. varium and also the first record of this rickettsia in Peru. In addition, an immature A. calcaratum is reported from Peru for the first time. PMID:22809734

Ogrzewalska, Maria; Literak, Ivan; Cardenas-Callirgos, Jorge M; Capek, Miroslav; Labruna, Marcelo B

2012-09-01

171

Detection of Rickettsia prowazekii in Body Lice and Their Feces by Using Monoclonal Antibodies  

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In order to identify Rickettsia prowazekii in lice, we developed a panel of 29 representative monoclonal antibodies selected from 187 positive hybridomas made by fusing splenocytes of immunized mice with SP2/0-Ag14 myeloma cells. Immunoblotting revealed that 15 monoclonal antibodies reacted with the lipopolysaccharide-like (LPS-L) antigen and 14 reacted with the epitopes of a 120-kDa protein. Only typhus group rickettsiae reacted with the monoclonal antibodies against LPS-L. R. felis, a recen...

Fang, Rong; Houhamdi, Linda; Raoult, Didier

2002-01-01

172

Use of Highly Variable Intergenic Spacer Sequences for Multispacer Typing of Rickettsia conorii Strains  

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By use of the nearly perfectly colinear genomes of Rickettsia conorii and Rickettsia prowazekii, we compared the usefulness of three types of sequences for typing of R. conorii isolates: (i) 5 variable coding genes comprising the 16S ribosomal DNA, gltA, ompB, and sca4 (gene D) genes, which are present in both genomes, and the ompA gene, which is degraded in R. prowazekii; (ii) 28 genes degraded in R. conorii but intact in R. prowazekii, including 23 split and 5 remnant genes; and (iii) 27 co...

Fournier, Pierre-edouard; Zhu, Yong; Ogata, Hiroyuki; Raoult, Didier

2004-01-01

173

Selection of alpha/beta interferon- and gamma interferon-resistant rickettsiae by passage of Rickettsia prowazekii in L929 cells.  

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The ability of endogenously produced alpha/beta interferon (IFN-alpha/beta) to inhibit rickettsial growth in infected L929 cell cultures was evaluated by comparing the growth of Rickettsia prowazekii Madrid E in untreated cultures and cultures treated with anti-mouse IFN (alpha + beta) serum. The endogenously produced IFN was neutralized, and rickettsial growth was enhanced in the antiserum-treated cultures. This inhibitory effect of endogenously produced IFN-alpha/beta was used to select ric...

Turco, J.; Winkler, H. H.

1990-01-01

174

Rickettsia Sca2 is a bacterial formin-like mediator of actin-based motility.  

Science.gov (United States)

Diverse intracellular pathogens subvert the host actin-polymerization machinery to drive movement within and between cells during infection. Rickettsia in the spotted fever group (SFG) are Gram-negative, obligate intracellular bacterial pathogens that undergo actin-based motility and assemble distinctive 'comet tails' that consist of long, unbranched actin filaments. Despite this distinct organization, it was proposed that actin in Rickettsia comet tails is nucleated by the host Arp2/3 complex and the bacterial protein RickA, which assemble branched actin networks. However, a second bacterial gene, sca2, was recently implicated in actin-tail formation by R. rickettsii. Here, we demonstrate that Sca2 is a bacterial actin-assembly factor that functionally mimics eukaryotic formin proteins. Sca2 nucleates unbranched actin filaments, processively associates with growing barbed ends, requires profilin for efficient elongation, and inhibits the activity of capping protein, all properties shared with formins. Sca2 localizes to the Rickettsia surface and is sufficient to promote the assembly of actin filaments in cytoplasmic extract. These results suggest that Sca2 mimics formins to determine the unique organization of actin filaments in Rickettsia tails and drive bacterial motility, independently of host nucleators. PMID:20972427

Haglund, Cat M; Choe, Julie E; Skau, Colleen T; Kovar, David R; Welch, Matthew D

2010-11-01

175

Transformation frequency of a mariner-based transposon in Rickettsia rickettsii.  

Science.gov (United States)

Transformation frequencies of a mariner-based transposon system in Rickettsia rickettsii were determined using a plaque assay system for enumeration and isolation of mutants. Sequence analysis of insertion sites in both R. rickettsii and R. prowazekii indicated that insertions were random. Transposon mutagenesis provides a useful tool for rickettsial research. PMID:21764933

Clark, Tina R; Lackey, Amanda M; Kleba, Betsy; Driskell, Lonnie O; Lutter, Erika I; Martens, Craig; Wood, David O; Hackstadt, Ted

2011-09-01

176

Expression of the Rickettsia prowazekii citrate synthase gene in Escherichia coli.  

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Recombinant DNA techniques were used to isolate the Rickettsia prowazekii citrate synthase gene on the plasmid vector pBR322 by functional complementation of a gltA mutation of Escherichia coli K-12. Analysis of citrate synthase activity in crude extracts revealed that the enzyme expressed in E. coli retains the regulatory control mechanisms characteristic of the rickettsial enzyme.

Wood, D. O.; Atkinson, W. H.; Sikorski, R. S.; Winkler, H. H.

1983-01-01

177

Unusual organization of the rRNA genes in Rickettsia prowazekii.  

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We describe here the organization of the rRNA genes in Rickettsia prowazekii. In this organism, the 23S and the 5S rRNA genes are tightly linked to each other, whereas the 16S rRNA gene is separated from this cluster. The 23S-5S unit is preceded by the methionyl-tRNAfMet formyltransferase gene.

Andersson, S. G.; Zomorodipour, A.; Winkler, H. H.; Kurland, C. G.

1995-01-01

178

Transformation Frequency of a mariner-Based Transposon in Rickettsia rickettsii ? §  

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Transformation frequencies of a mariner-based transposon system in Rickettsia rickettsii were determined using a plaque assay system for enumeration and isolation of mutants. Sequence analysis of insertion sites in both R. rickettsii and R. prowazekii indicated that insertions were random. Transposon mutagenesis provides a useful tool for rickettsial research.

Clark, Tina R.; Lackey, Amanda M.; Kleba, Betsy; Driskell, Lonnie O.; Lutter, Erika I.; Martens, Craig; Wood, David O.; Hackstadt, Ted

2011-01-01

179

Isolation of Rickettsia prowazekii from Blood by Shell Vial Cell Culture  

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A blood sample from a patient who returned from Algeria with a fever inoculated on human embryonic lung fibroblasts by the shell vial cell culture technique led to the recovery of Rickettsia prowazekii. The last clinical strain was isolated 30 years ago. Shell vial cell culture is a versatile method that could replace the classic animal and/or embryonated egg inoculation.

Birg, Marie-laure; La Scola, Bernard; Roux, Ve?ronique; Brouqui, Philippe; Raoult, Didier

1999-01-01

180

Characterization of a new antigenic type, Kuroki, of Rickettsia tsutsugamushi isolated from a patient in Japan.  

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The Kuroki strain of Rickettsia tsutsugamushi, isolated from a patient in Kyushu, Japan, has a major, type-specific antigenic polypeptide which is distinct from the prototype strains in size (58 kilodaltons), in antigenicity, and in its cleavage pattern with N-chlorosuccinimide. These results indicate that Kuroki is another antigenic type of R. tsutsugamushi.

Ohashi, N.; Tamura, A.; Sakurai, H.; Yamamoto, S.

1990-01-01

 
 
 
 
181

Seroepidemiologic study of human infections with spotted Fever group rickettsiae in north Carolina.  

Science.gov (United States)

Increasing entomologic and epidemiologic evidence suggests that spotted fever group rickettsiae (SFGR) other than Rickettsia rickettsii are responsible for spotted fever rickettsioses in the United States. A retrospective seroepidemiologic study was conducted on stored acute- and convalescent-phase sera that had been submitted for Rocky Mountain spotted fever testing to the North Carolina State Laboratory of Public Health. We evaluated the serologic reactivity of the paired sera to R. rickettsii, Rickettsia parkeri, and Rickettsia amblyommii antigens. Of the 106 eligible pairs tested, 21 patients seroconverted to one or more antigens. Cross-reactivity to multiple antigens was observed in 10 patients, and seroconversions to single antigens occurred in 11 patients, including 1 against R. rickettsii, 4 against R. parkeri, and 6 against R. amblyommii. Cross-absorption of cross-reactive sera and/or Western blots identified two presumptive cases of infection with R. parkeri, two presumptive cases of infection with R. rickettsii, and one presumptive case of infection with R. amblyommii. These findings suggest that species of SFGR other than R. rickettsii are associated with illness among North Carolina residents and that serologic testing using R. rickettsii antigen may miss cases of spotted fever rickettsioses caused by other species of SFGR. PMID:25187639

Vaughn, Meagan F; Delisle, Josie; Johnson, Joey; Daves, Gaylen; Williams, Carl; Reber, Jodi; Mendell, Nicole L; Bouyer, Donald H; Nicholson, William L; Moncayo, Abelardo C; Meshnick, Steven R

2014-11-01

182

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

DEFF Research Database (Denmark)

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 Ricekttsia was found without problems of cross-reactions with bacterial species shown to cross-react serologically.

Svendsen, Claus Bo; Boye, Mette

2009-01-01

183

Rickettsiae and ehrlichiae within a city park: is the urban dweller at risk?  

Science.gov (United States)

Tick-borne diseases, such as spotted fever rickettsioses and ehrlichioses, are potentially severe and life-threatening infections. The incidences of these infections increase during warm weather months as ticks become active. Clinicians often consider outdoor activities in rural areas to be a risk factor for exposure to ticks and the pathogens they carry, but are those who live, work, and play within an urban environment excluded from this risk? In this study, we collected ticks from two urban parks in Little Rock, AR, to assess the presence of rickettsiae and ehrlichiae within an urban setting. A total of 273 ticks were collected during July, 2011. Amblyomma americanum was the predominant tick species, with 255 (93%) of those collected. The remaining 18 (7%) were Dermacentor variabilis. Ticks were separated and pooled into groups for further testing. Forty-two of the 43 (98%) A. americanum pools demonstrated molecular evidence for the presence of rickettsiae. None of the D. variabilis contained rickettsiae. Restriction enzyme fragment length polymorphism analysis and DNA sequencing revealed Rickettsia amblyommii to be the species present. One A. americanum pool from park A demonstrated the presence of Ehrlichia chaffeensis, the pathogen responsible for human monocytotropic ehrlichiosis. These results indicate that tick-borne pathogens are not limited to rural or suburban areas. PMID:24528097

Blanton, Lucas S; Walker, David H; Bouyer, Donald H

2014-02-01

184

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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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 an...

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

2011-01-01

185

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

2013-01-01

186

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

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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.

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

2013-01-01

187

Penetration of host cells by Rickettsia rickettsii appears to be mediated by a phospholipase of rickettsial origin.  

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Internalization of obligate intracellular bacteria belonging to the genus Rickettsia by eukaryotic cells requires participation of both the parasitized host and the microorganism. The term "induced phagocytosis" has been used specifically to describe the entry of Rickettsia prowazekii, although a similar mechanism is likely for R. rickettsii. A role for a phospholipase in the internalization process has been proposed for both of these organisms, with the strongest supporting evidence provided...

Silverman, D. J.; Santucci, L. A.; Meyers, N.; Sekeyova, Z.

1992-01-01

188

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish 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. Abstract in english 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 patient [...] s 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.

189

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  

Directory of Open Access Journals (Sweden)

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

2003-12-01

190

Detection of Babesia Sp. EU1 and members of spotted fever group rickettsiae in ticks collected from migratory birds at Curonian Spit, North-Western Russia.  

Science.gov (United States)

To reveal the prevalence of spotted fever group (SFG) rickettsiae and Babesia sp. in Ixodes ricinus (L.) ticks from migratory birds, 236 specimens represented 8 species of Passeriformes and were collected at Curonian Spit in Kaliningrad enclave of North-Western Russia. The ticks (total 126) being detached from four bird species, Turdus philomelos, Fringilla coelebs, Parus major, and Sturnus vulgaris, were investigated by PCR using the primers Rp CS.877p/Rp CS.1258n for the detection of Rickettsia and BJ1/BN2 for Babesia spp. Babesia spp. were detected in 2 of 126 (1.6%) ticks. The partial sequence of 18S rDNA had 100% similarity to human pathogenic Babesia sp. EU1. The SFG rickettsiae were detected in 19 of 126 (15.1%) ticks collected from the above-mentioned bird species. BLAST analysis of SFG rickettsia gltA assigned sequences to human pathogenic Rickettsia helvetica (10.3%), Rickettsia monacensis (3.9%), and Rickettsia japonica (0.8%) with 98%-100% sequence similarity. The SFG rickettsiae and Babesia sp. EU1 in ticks collected from the passerines in Russia were detected for the first time. The survey indicates that migratory birds may become a reservoir for Babesia spp. and SFG rickettsiae. Future investigations need to characterize the role of birds in the epidemiology of these human pathogens in the region. PMID:20553110

Movila, Alexandru; Reye, Anna L; Dubinina, Helen V; Tolstenkov, Oleg O; Toderas, Ion; Hübschen, Judith M; Muller, Claude P; Alekseev, Andrey N

2011-01-01

191

Genotypic comparison of five isolates of Rickettsia prowazekii by multilocus sequence typing.  

Science.gov (United States)

Genetic traits of five Rickettsia prowazekii isolates, including the first from Africa and North America, and representatives from human and flying squirrels were compared using multilocus sequence typing. Four rickettsial genes encoding 17 kDa genus-common antigen (17 kDa gene), citrate synthase (gltA), OmpB immunodominant antigen (ompB) and 120 kDa cytoplasmic antigen (sca4) were examined. Sequence identities of 17 kDa gene and gltA were 100% among the isolates. Limited sequence diversity of ompB (0.02-0.11%) and sca4 (0.03-0.20%) was enough to distinguish the isolates, and evaluation of the combined four genes provided a method to easily differentiate R. prowazekii from other rickettsiae. PMID:17419766

Ge, Hong; Tong, Min; Jiang, Ju; Dasch, Gregory A; Richards, Allen L

2007-06-01

192

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

Science.gov (United States)

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. PMID:23168055

Djerbouh, Amel; Kernif, Tahar; Beneldjouzi, Assia; Socolovschi, Cristina; Kechemir, Nadia; Parola, Philippe; Raoult, Didier; Bitam, Idir

2012-12-01

193

First molecular detection of Rickettsia parkeri in Amblyomma tigrinum and Amblyomma dubitatum ticks from Uruguay.  

Science.gov (United States)

Rickettsia parkei is the etiological agent of spotted fever in Uruguay, where is transmitted to humans by the tick Amblyomma triste. In the present study, ticks were collected from capybaras (Hydrochoerus hydrochaeris) and domestic dogs during 2011-2012 in different parts of Uruguay. Three out of 11 (27.3%) Amblyomma dubitatum ticks collected from capybaras, and 4 out of 6 (66.7%) Amblyomma tigrinum ticks collected from dogs were shown by molecular analyses to be infected by Rickettsia parkeri strain Maculatum 20. Until the present work, A. triste was the only tick species that was found infected by R. parkeri in Uruguay. This is the first report of R. parkeri infecting these two tick species in Uruguay, expanding the current distribution of this rickettsial pathogen in the country. PMID:25108780

Lado, Paula; Castro, Oscar; Labruna, Marcelo B; Venzal, José M

2014-10-01

194

Directed Mutagenesis of the Rickettsia prowazekii pld Gene Encoding Phospholipase D ? §  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rickettsia prowazekii, the causative agent of epidemic typhus, is an obligately intracytoplasmic bacterium, a lifestyle that imposes significant barriers to genetic manipulation. The key to understanding how this unique bacterium evades host immunity is the mutagenesis of selected genes hypothesized to be involved in virulence. The R. prowazekii pld gene, encoding a protein with phospholipase D activity, has been associated with phagosomal escape. To demonstrate the feasibility of site-direct...

Driskell, Lonnie O.; Yu, Xue-jie; Zhang, Lihong; Liu, Yan; Popov, Vsevolod L.; Walker, David H.; Tucker, Aimee M.; Wood, David O.

2009-01-01

195

Multispacer Typing of Rickettsia prowazekii Enabling Epidemiological Studies of Epidemic Typhus†  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Currently, there is no tool for typing Rickettsia prowazekii, the causative agent of epidemic typhus, currently considered a potential bioterrorism agent, at the strain level. To test if the multispacer typing (MST) method could differentiate strains of R. prowazekii, we amplified and sequenced the 25 most variable intergenic spacers between the R. prowazekii and R. conorii genomes in five strains and 10 body louse amplicons of R. prowazekii from various geographic origins. Two intergenic spa...

Zhu, Yong; Fournier, Pierre-edouard; Ogata, Hiroyuki; Raoult, Didier

2005-01-01

196

Phospholipase A activity associated with the growth of Rickettsia prowazekii in L929 cells.  

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Cultured L929 cells infected with Rickettsia prowazekii had a greatly increased rate of hydrolysis of fatty acid from the oleic acid-radiolabeled phospholipids of the host cell membranes. The incorporation of fatty acid into phospholipid in an infected cell was only moderately inhibited relative to a mock-infected cell. Thus, even if the release of fatty acid from phospholipid represented a steady state between hydrolysis and resynthesis of phospholipids, the increase in release of fatty acid...

Winkler, H. H.; Daugherty, R. M.

1989-01-01

197

Rickettsia prowazekii Transports UMP and GMP, but Not CMP, as Building Blocks for RNA Synthesis  

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Rickettsia prowazekii, the etiological agent of epidemic typhus, is an obligate intracellular bacterium and is apparently unable to synthesize ribonucleotides de novo. Here, we show that as an alternative, isolated, purified R. prowazekii organisms transported exogenous uridyl- and guanylribonucleotides and incorporated these labeled precursors into their RNA in a rifampin-sensitive manner. Transport systems for nucleotides, which we have shown previously and show here are present in ricketts...

Winkler, Herbert H.; Daugherty, Robin; Hu, Fuquan

1999-01-01

198

Transcriptional analysis of the 16s rRNA gene in Rickettsia prowazekii.  

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The control of rRNA synthesis in the etiological agent of epidemic typhus, Rickettsia prowazekii, a slowly growing obligate intracytoplasmic bacterium, was investigated. Transcription of the rickettsial 16S rRNA gene (rrs), of which there is only a single copy, was controlled by a single promoter region, and the site for the initiation of transcription (base A) was found 117 bp upstream of the rrs coding region for the mature product. The promoter region contained an Escherichia coli promoter...

Pang, H.; Winkler, H. H.

1996-01-01

199

DNA Microarray Analysis of the Heat Shock Transcriptome of the Obligate Intracytoplasmic Pathogen Rickettsia prowazekii? †  

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Here we present the first oligonucleotide DNA microarray analysis of global gene expression changes in the obligate intracytoplasmic pathogen Rickettsia prowazekii using temperature upshift as a model stress condition, and we describe a methodology for isolating highly purified rickettsial RNA. In toto, 23 transcripts were significantly increased by temperature upshift (?2.0-fold; P < 0.05), and no transcripts demonstrated reproducible decreases. Array results for three heat shock-inducible...

Audia, Jonathon P.; Patton, Mary C.; Winkler, Herbert H.

2008-01-01

200

Identification and initial topological analysis of the Rickettsia prowazekii ATP/ADP translocase.  

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The Rickettsia prowazekii ATP/ADP translocase was identified by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) and immunoblot analysis using antibodies raised against a synthetic peptide corresponding in sequence to the carboxyl-terminal 17 amino acids of the carrier. Both the translocase of R. prowazekii and that expressed by Escherichia coli transformants containing the rickettsial gene had an apparent molecular mass of 36,500 Da by SDS-PAGE analysis, a mass consider...

Plano, G. V.; Winkler, H. H.

1991-01-01

 
 
 
 
201

Deamination of deoxycytidine nucleotides by the obligate intracytoplasmic bacterium Rickettsia prowazekii.  

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Thymidylate biosynthesis via the methylation of dUMP is required for DNA replication in Rickettsia prowazekii, an obligate intracytoplasmic bacterium. In theory, dUMP synthesis could occur either by the deamination of deoxycytidine nucleotides or by the reduction of uridine nucleotides. Accordingly, the incorporation of both radiolabeled cytidine and uridine into the thymidylate of R. prowazekii was examined. After DNA hydrolysis and high-performance liquid chromatography, it was determined t...

Speed, R. R.; Winkler, H. H.

1991-01-01

202

Genomic, proteomic, and transcriptomic analysis of virulent and avirulent Rickettsia prowazekii reveals its adaptive mutation capabilities  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rickettsia prowazekii, the agent of epidemic typhus, is an obligate intracellular bacterium that is transmitted to human beings by the body louse. Several strains that differ considerably in virulence are recognized, but the genetic basis for these variations has remained unknown since the initial description of the avirulent vaccine strain nearly 70 yr ago. We use a recently developed murine model of epidemic typhus and transcriptomic, proteomic, and genetic techniques to identify the factor...

Bechah, Yassina; El Karkouri, Khalid; Mediannikov, Oleg; Leroy, Quentin; Pelletier, Nicolas; Robert, Catherine; Me?digue, Claudine; Mege, Jean-louis; Raoult, Didier

2010-01-01

203

Conserved Gene Cluster at Replication Origins of the ?-Proteobacteria Caulobacter crescentus and Rickettsia prowazekii  

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A 30-kb region surrounding the replication origin in Caulobacter crescentus was analyzed. Comparison to the genome sequence of another ?-proteobacterium, Rickettsia prowazekii, revealed a conserved cluster of genes (RP001, hemE, hemH, and RP883) that overlaps the established origin of replication in C. crescentus and the putative origin of replication in R. prowazekii. The genes flanking this cluster differ between these two organisms. We therefore propose that this conserved gene cluster ca...

Brassinga, Ann Karen C.; Siam, Rania; Marczynski, Gregory T.

2001-01-01

204

Transformation of Rickettsia prowazekii to Erythromycin Resistance Encoded by the Escherichia coli ereB Gene  

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Rickettsia prowazekii, the etiologic agent of epidemic typhus, is an obligate, intracytoplasmic, parasitic bacterium. Recently, the transformation of this bacterium via electroporation has been reported. However, in these studies identification of transformants was dependent upon either selection of an R. prowazekii rpoB chromosomal mutation imparting rifampin resistance or expression of the green fluorescent protein and flow cytometric analysis. In this paper we describe the expression in R....

Rachek, Lyudmila I.; Hines, Andria; Tucker, Aimee M.; Winkler, Herbert H.; Wood, David O.

2000-01-01

205

Rickettsia-like organism infecting juvenile sea-bass Dicentrarchus labrax  

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High levels of mortalities (20%) associated with abnormal swimming have been observed in farmed juveniles of seabass, Dicentrarchus labrax, in Mediterranean coast, southern France. Histopathology was obvious in the brain with nervOUS tissue necrosis and the presence of ceUs containing basophilic granules corresponding to smaU coccoid organisms. Ultrastructural examination revealed these organisms were rickettsia-like organisms morphologicaUy close to Piscirickettsia salmonis

Comps, Michel; Raymond, J. C.; Plassiart, G. N.

1996-01-01

206

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

Science.gov (United States)

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. PMID:23838023

Tappe, Julia; Strube, Christina

2013-09-01

207

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 aureolatu [...] m, 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.

Alessandra Pereira, Medeiros; Antonio Pereira de, Souza; Anderson Barbosa de, Moura; Marcia Sangaletti, Lavina; Valdomiro, Bellato; Amélia Aparecida, Sartor; Fernanda Aparecida, Nieri-Bastos; Leonardo José, Richtzenhain; Marcelo Bahia, Labruna.

2011-12-01

208

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

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Full Text Available 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.

Alessandra Pereira Medeiros

2011-12-01

209

Rickettsial diseases: from Rickettsia-arthropod relationships to pathophysiology and animal models.  

Science.gov (United States)

Rickettsiae cause spotted fevers and typhus-related diseases in humans. Some of these diseases occur worldwide and are life-threatening, for example, epidemic typhus is still a major health problem despite the apparent efficiency of antibiotic treatment. In addition, Rickettsia prowazekii, the agent of epidemic typhus, and R. rickettsii, the agent of Rocky Mountain spotted fever, are microorganisms that could potentially be used as bioweapons to induce panic in the population. Rickettsiae are obligate intracellular bacteria in both vertebrate and invertebrate hosts, but rickettsial species differ in terms of association with arthropods, behavior of the vector to infection, pathophysiology and outcome of the disease. Understanding the pathogenic steps of rickettsioses is essential to develop protective strategies against these bacteriological threats. Unfortunately, the mechanisms involved in the pathogenesis of many rickettsioses are poorly characterized, and protective immunity is incompletely understood, in part because accurate animal models that mimic human diseases are lacking. In the past, murine models have been of limited value because infection of mice was without effect or resulted in erratic mortality. Recent studies have reported that rickettsial infection can be established in mice, depending on the genetic background of mice, the type of rickettsial species and the route of inoculation. These models may be useful for analyzing the pathogenesis of rickettsioses, especially epidemic typhus, evaluating new therapeutic molecules and vaccine candidates, and preventing future outbreaks. PMID:18366341

Bechah, Yassina; Capo, Christian; Mege, Jean-Louis; Raoult, Didier

2008-04-01

210

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

2008-08-01

211

Prevalence of Rickettsiales (Anaplasma phagocytophilum and Rickettsia spp.) in hard ticks (Ixodes ricinus) in the city of Hamburg, Germany.  

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To narrow the gap of missing knowledge on Rickettsia spp. and Anaplasma phagocytophilum infections in ticks in northwestern Germany and, at the same time, to provide first prevalence data on these pathogens in the city of Hamburg, a total of 1,400 questing Ixodes ricinus ticks were collected at ten different public green areas from April until October 2011. Ticks were examined using probe-based quantitative real-time PCR. A percentage of 3.6% (51/1,400) ticks were tested positive for A. phagocytophilum infections divided into 2.1% (3/141) adults [1.7% (1/60) females and 2.5% (2/81) males] and 3.8% (48/1,259) nymphs. The percentage of infected ticks per sampling site varied statistically significantly from 0.7% (1/140) to 12.1% (17/140), whereas between sampling months, no statistically significant differences were observed (2.0-6.5%, 4-13/140). The overall Rickettsia spp. infection rate was 52.5% (735/1,400). In adult ticks, Rickettsia spp. infection rate was 56% (79/141) divided into 61.7% (37/60) infected females and 51.9% (42/81) infected males. Nymphs showed an infection rate of 52.1% (656/1,259). In contrast to A. phagocytophilum infections, no statistically significant differences in Rickettsia spp. infection rates among sampling sites (44.3-63.6%, 62-89/140) were observed, whereas seasonal variations were obvious: the percentage of Rickettsia-positive ticks was significantly lower in April (36.5%, 73/200) and May (29.5%, 59/200) compared to the summer and fall months (55.0-64.5%, 110-129/200). Rickettsia species differentiation via real-time pyrosequencing revealed Rickettsia helvetica as the only occurring species. Co-infections with both Rickettsia spp. and A. phagocytophilum were detected in 2.0% (28/1,400) of the ticks. The present study revealed that in the city of Hamburg, the tick infection rate with A. phagocytophilum is comparable with other German data, whereas the Rickettsia spp. infection rate of 52.5% is by far the highest prevalence detected in Germany so far. As the city of Hamburg has 1.8 million inhabitants and attracts millions of tourists every year, the potential health risk should not be underestimated. PMID:24728556

May, Kathrin; Strube, Christina

2014-06-01

212

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 SciELO Brazil | Language: English 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 ob [...] tidos foram testados para anticorpos anti-Rickettsia spp. pela Reação de Imunofluorescência Indireta (RIFI). A ocorrência de anticorpos anti-Rickettsia spp. observada 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 coll [...] ected and anti-Rickettsia spp. antibodies were evaluated by indirect immunofluorescence assay (IFA) in the sera obtained. The occurrence of anti-Rickettsia spp. antibodies detected 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.

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

2037-20-01

213

Discovery of novel cross-protective Rickettsia prowazekii T-cell antigens using a combined reverse vaccinology and in vivo screening approach.  

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Rickettsial agents are some of the most lethal pathogens known to man. Among them, Rickettsia prowazekii is a select agent with potential use for bioterrorism; yet, there is no anti-Rickettsia vaccine commercially available. Owing to the obligate intracellular lifestyle of rickettsiae, CD8(+) T cells are indispensable for protective cellular immunity. Furthermore, T cells can mediate cross-protective immunity between different pathogenic Rickettsia, a finding consistent with the remarkable similarity among rickettsial genomes. However, Rickettsia T cell antigens remain unidentified. In the present study, we report an algorithm that allowed us to identify and validate four novel R. prowazekii vaccine antigen candidates recognized by CD8(+) T cells from a set of twelve in silico-defined protein targets. Our results highlight the importance of combining proteasome-processing as well as MHC class-I-binding predictions. The novel rickettsial vaccine candidate antigens, RP778, RP739, RP598, and RP403, protected mice against a lethal challenge with Rickettsia typhi, which is indicative of cross-protective immunity within the typhus group rickettsiae. Together, our findings validate a reverse vaccinology approach as a viable strategy to identify protective rickettsial antigens and highlight the feasibility of a subunit vaccine that triggers T-cell-mediated cross-protection among diverse rickettsiae. PMID:25010827

Caro-Gomez, Erika; Gazi, Michal; Goez, Yenny; Valbuena, Gustavo

2014-09-01

214

Borrelia, Coxiella, and Rickettsia in Carios capensis (Acari: Argasidae) from a brown pelican (Pelecanus occidentalis) rookery in South Carolina, USA.  

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Argasid ticks are vectors of viral and bacterial agents of humans and animals. Carios capensis, a tick of seabirds, infests the nests of brown pelicans, Pelecanus occidentalis, and other ground nesting birds along the coast of South Carolina. This tick is associated with pelican nest abandonment and could pose a threat to humans visiting pelican rookeries if visitors are exposed to ticks harboring infectious agents. We collected ticks from a pelican rookery on Deveaux Bank, South Carolina and screened 64 individual ticks, six pools of larvae, and an egg mass for DNA from Bartonella, Borrelia, Coxiella, and Rickettsia by polymerase chain reaction amplification and sequencing. Ticks harbored DNA from "Borrelia lonestari", a novel Coxiella sp., and three species of Rickettsia, including Rickettsia felis and two undescribed Rickettsia spp. DNA from the Coxiella and two undescribed Rickettsia were detected in unfed larvae that emerged in the laboratory, which implies these agents are transmitted vertically by female ticks. We partially characterize the novel Coxiella by molecular means. PMID:16821092

Reeves, Will K; Loftis, Amanda D; Sanders, Felicia; Spinks, Mark D; Wills, William; Denison, Amy M; Dasch, Gregory A

2006-01-01

215

High prevalence of Rickettsia typhi and Bartonella species in rats and fleas, Kisangani, Democratic Republic of the Congo.  

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The prevalence and identity of Rickettsia and Bartonella in urban rat and flea populations were evaluated in Kisangani, Democratic Republic of the Congo (DRC) by molecular tools. An overall prevalence of 17% Bartonella species and 13% Rickettsia typhi, the agent of murine typhus, was found in the cosmopolitan rat species, Rattus rattus and Rattus norvegicus that were infested by a majority of Xenopsylla cheopis fleas. Bartonella queenslandensis, Bartonella elizabethae, and three Bartonella genotypes were identified by sequencing in rat specimens, mostly in R. rattus. Rickettsia typhi was detected in 72% of X. cheopis pools, the main vector and reservoir of this zoonotic pathogen. Co-infections were observed in rodents, suggesting a common mammalian host shared by R. typhi and Bartonella spp. Thus, both infections are endemic in DRC and the medical staffs need to be aware knowing the high prevalence of impoverished populations or immunocompromised inhabitants in this area. PMID:24445202

Laudisoit, Anne; Falay, Dadi; Amundala, Nicaise; Akaibe, Dudu; de Bellocq, Joëlle Goüy; Van Houtte, Natalie; Breno, Matteo; Verheyen, Erik; Wilschut, Liesbeth; Parola, Philippe; Raoult, Didier; Socolovschi, Cristina

2014-03-01

216

Prevalence of vectors of the spotted fever group Rickettsiae and murine typhus in a Bedouin town in Israel.  

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A survey of the vectors of spotted fever group Rickettsiae and of murine typhus was carried out in Rahat, a Bedouin town in the Negev Desert, where the diseases are endemic. Houses with known cases of spotted fever group Rickettsiae or murine typhus were compared with those without reported clinical cases. A neighboring Jewish community, Lehavim, where no cases of spotted fever group Rickettsiae and murine typhus were reported in recent years, was used as a control. In the houses of patients with spotted fever group Rickettsiae in Rahat, an average of 7.4 times more ticks were found than in control houses. Out of 190 ticks isolated from sheep and goats or caught by flagging in Rahat, 90% were Rhipicephalus sanguineus (Latreille), 7.9% Rhipicephalus turanicus Pomerantzev, and 2.1% were Hyalomma sp. In the houses of patients with murine typhus, three times more rats were caught and, on the average, each rat was infested with 2.2 times more fleas than rats in the control houses. Out of 323 fleas collected from 35 Norwegian rats (Rattus norvegicus Berkenhout), 191 were Xenopsylla cheopis Rothschild and 132 Echidnophaga murina Tiraboschi. Thus, there was a six to seven times higher probability of encountering a tick or flea vector where infections had occurred than in control houses in Rahat. The percentage of rats seropositive to Rickettsia typhi was similar in study and control households (78.3 and 76.2, respectively). In the control settlement, Lehavim, only three Mus musculus L. were caught, which were not infested with ectoparasites and their sera were negative for murine typhus. Out of 10 dogs examined in this settlement, 15 R. sanguineus and eight specimens of the cat flea (Ctenocephalides felis felis Bouché) were isolated. No rats were caught in this settlement. These data indicate that there is a correlation among the density of domestic animals, their ectoparasites, and the incidence of spotted fever group Rickettsiae and murine typhus in Rahat. PMID:11372975

Mumcuoglu, K Y; Ioffe-Uspensky, I; Alkrinawi, S; Sarov, B; Manor, E; Galun, R

2001-05-01

217

Detection of Rickettsia felis and Rickettsia typhi and seasonal prevalence of fleas collected from small mammals at Gyeonggi Province in the Republic of Korea.  

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Fleas were collected from live-captured small mammals to identify flea-borne pathogens, host associations, and seasonal prevalence of flea species, as part of the 65th Medical Brigade rodent-borne disease surveillance program at 20 military installations and training sites, Gyeonggi Province, Republic of Korea, 2005-2007. A total of 1251 fleas were recovered from 2833 small mammals. Apodemus agrarius, the striped field mouse, accounted for 93.1% (2,637/2,833) of all small mammals captured, followed by Crocidura lasiura (3.1%), Mus musculus (1.3%), Microtus fortis (0.7%), Myodes regulus (0.7%), Micromys minutus (0.5%), Rattus norvegicus (0.4%), Tscherskia triton (0.1%), Apodemus peninsulae (< 0.1%), Rattus rattus (< 0.1%), and Mogera robusta (< 0.1%). A total of 6/11 species of mammals captured were infested with fleas with infestation rates ranging from a high of 26.3% (A. agrarius and M. regulus) to a low of 5.3% (M. fortis). Flea indices among infested mammals were highest for R. norvegicus (2.50), followed by C. lasiura (2.20), A. agrarius (1.71), M. regulus (1.20), M. musculus (1.0), and M. fortis (1.0). The predominant flea species collected were Stenoponia sidimi (56.5%), followed by Ctenophthalmus congeneroides (38.3%) and Rhadinopsylla insolita (3.9%). The minimum field infection rates [number of positive pools/total number of fleas (600)] for Rickettsia typhi and for Rickettsia felis were 1.7% and 1.0%, respectively. PMID:21612536

Ko, Sungjin; Kim, Heung-Chul; Yang, Young-Cheol; Chong, Sung-Tae; Richards, Allen L; Sames, William J; Klein, Terry A; Kang, Jun-Gu; Chae, Joon-Seok

2011-09-01

218

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

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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

2008-11-01

219

Cloning and expression of the Rickettsia prowazekii ADP/ATP translocator in Escherichia coli.  

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Cosmid clone banks of Rickettsia prowazekii genomic DNA were established in Escherichia coli and screened for expression of the rickettsial carrier-mediated ADP/ATP translocator. Out of 2700 clones screened, a single clone, designated MOB286, accumulated radioactivity when incubated with [alpha-32P]ATP in 100 mM sodium phosphate buffer. This clone carried a plasmid, pMW286, containing a 9-kilobase-pair insert of rickettsial DNA, as established by DNA X DNA hybridizations. Transformation studi...

Krause, D. C.; Winkler, H. H.; Wood, D. O.

1985-01-01

220

Copy number of the 16S rRNA gene in Rickettsia prowazekii.  

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The obligate intracellular parasite, Rickettsia prowazekii, is a slowly growing bacterium with a doubling time of 8 to 12 h. The copy number of the 16S rRNA gene in the rickettsial chromosome was determined to be one. Genomic DNA from R. prowazekii was digested either by a variety of restriction enzymes known not to cut at any site in the rickettsial 16S rRNA gene or by a combination of these noncutting enzymes and SmaI, which cuts the gene only once. Only one DNA fragment in these digests hy...

Pang, H.; Winkler, H. H.

1993-01-01

 
 
 
 
221

A chimeric disposition of the elongation factor genes in Rickettsia prowazekii.  

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An exceptional disposition of the elongation factor genes is observed in Rickettsia prowazekii, in which there is only one tuf gene, which is distant from the lone fus gene. In contrast, the closely related bacterium Agrobacterium tumefaciens has the normal bacterial arrangement of two tuf genes, of which one is tightly linked to the fus gene. Analysis of the flanking sequences of the single tuf gene in R. prowazekii shows that it is preceded by two of the four tRNA genes located in the 5' re...

Syva?nen, A. C.; Amiri, H.; Jamal, A.; Andersson, S. G.; Kurland, C. G.

1996-01-01

222

DNA microarray analysis of the heat shock transcriptome of the obligate intracytoplasmic pathogen Rickettsia prowazekii.  

Science.gov (United States)

Here we present the first oligonucleotide DNA microarray analysis of global gene expression changes in the obligate intracytoplasmic pathogen Rickettsia prowazekii using temperature upshift as a model stress condition, and we describe a methodology for isolating highly purified rickettsial RNA. In toto, 23 transcripts were significantly increased by temperature upshift (> or = 2.0-fold; P < 0.05), and no transcripts demonstrated reproducible decreases. Array results for three heat shock-inducible mRNAs were confirmed using quantitative reverse transcription-PCR. PMID:18952868

Audia, Jonathon P; Patton, Mary C; Winkler, Herbert H

2008-12-01

223

Regulatory role of phosphate and other anions in transport of ADP and ATP by Rickettsia prowazekii.  

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ADP and ATP were transported in Rickettsia prowazekii by an obligate exchange system without prior hydrolysis. The uptake of ATP and ADP by the obligate exchange system in R. prowazekii was dependent upon the anionic composition of the medium. The rate of transport of ATP was about three times greater than that of ADP in the absence of anions, and the rates of transport of both were about doubled by a variety of anions. However, phosphate anions were able to stimulate greatly the uptake of AD...

Winkler, H. H.; Daugherty, R. M.

1984-01-01

224

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

2013-01-01

225

Differentiation Between Virulent and Avirulent Strains of Rickettsia prowazekii by Macrophage-Like Cell Lines  

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The growth of avirulent (E) and virulent (Breinl) strains of Rickettsia prowazekii was compared in four mouse macrophage-like cell lines (RAW264.7, J774.1, P388D1, and PU5), one human macrophage-like cell line (U937-1), and the mouse fibroblast line L929. The E and Breinl strains grew equally well in L929 cells. However, all of the mouse macrophage-like cell lines clearly differentiated between the two strains by restricting the growth of the E strain relative to that of the Breinl strain. A ...

Turco, Jenifer; Winkler, Herbert H.

1982-01-01

226

Isolation and characterization of the Rickettsia prowazekii recA gene.  

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The recA gene has been isolated from Rickettsia prowazekii, an obligate intracellular bacterium. Comparison of the amino acid sequence of R. prowazekii RecA with that of Escherichia coli RecA revealed that 62% of the residues were identical. The highest identity was found with RecA of Legionella pneumophila, in which 69% of the residues were identical. Amino acid residues of E. coli RecA associated with functional activities are conserved in rickettsial RecA, and the R. prowazekii recA gene c...

Dunkin, S. M.; Wood, D. O.

1994-01-01

227

Cosmid cloning of Rickettsia prowazekii antigens in Escherichia coli K-12.  

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Rickettsia prowazekii DNA was partially digested with Sau3A or HindIII, ligated with the cosmid vector pHC79, packaged in vitro, and transduced into Escherichia coli HB101. Cosmid cloning of Sau3A-digested rickettsial DNA yielded 1,288 ampicillin-resistant colonies; 798 cosmid clones resulted with HindIII-digested rickettsial DNA. Chimeric cosmid DNA was extracted from the latter gene bank, digested to completion with HindIII, and compared by agarose gel electrophoresis with a HindIII digest ...

Krause, D. C.; Winkler, H. H.; Wood, D. O.

1985-01-01

228

[Pathomorphologic features in several phlebopathies associated with virus, rickettsia, chlamydia, and mycoplasma infections].  

Science.gov (United States)

Seventy-six venous specimens were examined by indirect immunofluorescence and histological techniques. 80.26% out of them gave negative I.F. reactions. The following causal agents were found on the I.F. positive preparations: Rickettsia burneti, Chlamydia, Mycoplasma, parainfluenza type 3 and adenoviruses, alone or associated. The most frequent lesion noted in I.F. positive specimens was of the inflammatory-dystrophic type. In I.F. negative preparations the dominant lesion was the hyalinosis of the tunica media. PMID:7756163

Petica, M; Athanasiu, P; Dumitrescu, S M; Petrescu, A

1994-01-01

229

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  

Directory of Open Access Journals (Sweden)

Full Text Available 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 promedio 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.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 operated 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.

GUILLERMO BANNURA C

2011-10-01

230

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 SciELO Brazil | Language: English 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 evolu [...] ir (grau III), é fundamental o diagnóstico preciso. OBJETIVOS: Identificar CG e corpos granulares eosinofílicos (CGE) em AP e XP, avaliar sua implicação na evolução 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 progre [...] ss 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 patient’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.

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

2013-06-01

231

[Use of quantitative measures of gene order similarity to phylogenetic reconstructions (exemplified by bacteria of the genus Rickettsia)].  

Science.gov (United States)

Data reflecting evolutionary changes in chromosomal gene order can be used for phylogenetic reconstructions along with the results of nucleotide sequence comparison. By the example of bacteria of the genus Rickettsia, we have shown that phylogenetic reconstructions based on quantitative estimates of the similarity and cladistic analysis of gene order data, may, in some cases, amend and fill up classical phylogenetic trees. When applied, these approaches enabled us to substantiate the hypothesis that Rickettsia felis species had split before the typhus (R. typhi, R. prowazekii) and spotted fever (R. connorii) group divergence and thus R. felis does not belong to the latter group. In general, rickettsias evolved towards increasing intracellular parasitic specialization. Five Rickettsia species whose genomes have been sequenced and annotated completely actually form an evolutionary series R. hellii-R. felis-R. connorii-R. prowazekii-R. typhi. Within this series, a reduction in genome size and rapid decrease of genome rearrangement rates (genome plasticity loss) gradually occur. PMID:18666548

Markov, A V; Zakharov, I A

2008-04-01

232

Surveillance of Egyptian fleas for agents of public health significance: Anaplasma, Bartonella, Coxiella, Ehrlichia, Rickettsia, and Yersinia pestis.  

Science.gov (United States)

Serologic surveys in Egypt have documented human and animal exposure to vector-borne bacterial pathogens, but the presence and distribution of these agents in arthropods has not been determined. Between July 2002 and July 2003, fleas were collected from 221 mammals trapped in 17 cities throughout Egypt. A total of 987 fleas were collected, representing four species (Ctenocephalides felis, Echidnophaga gallinacea, Leptopsylla segnis, and Xenopsylla cheopis); 899 of these fleas were X. cheopis from rats (Rattus spp.). Fleas were tested for DNA from Anaplasma spp., Bartonella spp., Coxiella burnetii, Ehrlichia spp., Rickettsia spp., and Yersinia pestis. Rickettsia typhi, the agent of murine typhus, was detected in X. cheopis and L. segnis from rats from nine cities. A spotted-fever group Rickettsia sp. similar to "RF2125" was detected in E. gallinacea, and two unidentified spotted fever group Rickettsia were detected in two X. cheopis. Novel Bartonella genotypes were detected in X. cheopis and L. segnis from three cities. Coxiella burnetii was detected in two fleas. Anaplasma, Ehrlichia, and Y. pestis were not detected. PMID:16837707

Loftis, Amanda D; Reeves, Will K; Szumlas, Daniel E; Abbassy, Magda M; Helmy, Ibrahim M; Moriarity, John R; Dasch, Gregory A

2006-07-01

233

Bartonella and Rickettsia in arthropods from the Lao PDR and from Borneo, Malaysia?  

Science.gov (United States)

Rickettsioses and bartonelloses are arthropod-borne diseases of mammals with widespread geographical distributions. Yet their occurrence in specific regions, their association with different vectors and hosts and the infection rate of arthropod-vectors with these agents remain poorly studied in South-east Asia. We conducted entomological field surveys in the Lao PDR (Laos) and Borneo, Malaysia by surveying fleas, ticks, and lice from domestic dogs and collected additional samples from domestic cows and pigs in Laos. Rickettsia felis was detected by real-time PCR with similar overall flea infection rate in Laos (76.6%, 69/90) and Borneo (74.4%, 268/360). Both of the encountered flea vectors Ctenocephalides orientis and Ctenocephalides felis felis were infected with R. felis. The degrees of similarity of partial gltA and ompA genes with recognized species indicate the rickettsia detected in two Boophilus spp. ticks collected from a cow in Laos may be a new species. Isolation and further characterization will be necessary to specify it as a new species. Bartonella clarridgeiae was detected in 3/90 (3.3%) and 2/360 (0.6%) of examined fleas from Laos and Borneo, respectively. Two fleas collected in Laos and one flea collected in Borneo were co-infected with both R. felis and B. clarridgeiae. Further investigations are needed in order to isolate these agents and to determine their epidemiology and aetiological role in unknown fever in patients from these areas. PMID:22153360

Kernif, Tahar; Socolovschi, Cristina; Wells, Konstans; Lakim, Maklarin B.; Inthalad, Saythong; Slesak, Gunther; Boudebouch, Najma; Beaucournu, Jean-Claude; Newton, Paul N.; Raoult, Didier; Parola, Philippe

2012-01-01

234

Adipose tissue serves as a reservoir for recrudescent Rickettsia prowazekii infection in a mouse model.  

Science.gov (United States)

Brill-Zinsser disease, the relapsing form of epidemic typhus, typically occurs in a susceptible host years or decades after the primary infection; however, the mechanisms of reactivation and the cellular reservoir during latency are poorly understood. Herein we describe a murine model for Brill-Zinsser disease, and use PCR and cell culture to show transient rickettsemia in mice treated with dexamethasone >3 months after clinical recovery from the primary infection. Treatment of similarly infected mice with cyclosporine failed to produce recrudescent bacteremia. Therapy with doxycycline for the primary infection prevented recrudescent bacteremia in most of these mice following treatment with dexamethasone. Rickettsia prowazekii (the etiologic agent of epidemic typhus) was detected by PCR, cell culture, and immunostaining methods in murine adipose tissue, but not in liver, spleen, lung, or central nervous system tissues of mice 4 months after recovery from the primary infection. The lungs of dexamethasone-treated mice showed impaired expression of beta-defensin transcripts that may be involved in the pathogenesis of pulmonary lesions. In vitro, R. prowazekii rickettsiae infected and replicated in the murine adipocyte cell line 3T3-L1. Collectively these data suggest a role for adipose tissue as a potential reservoir for dormant infections with R. prowazekii. PMID:20049326

Bechah, Yassina; Paddock, Christopher D; Capo, Christian; Mege, Jean-Louis; Raoult, Didier

2010-01-01

235

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)

236

Feeding by Amblyomma maculatum (Acari: Ixodidae) Enhances Rickettsia parkeri (Rickettsiales: Rickettsiaceae) Infection in the Skin  

Science.gov (United States)

Rickettsia parkeri Luckman (Rickettsiales: Rickettsiaceae), a member of the spotted fever group of Rickettsia, is the tick-borne causative agent of a newly recognized, eschar-associated rickettsiosis. Because of its relatively recent designation as a pathogen, few studies have examined the pathogenesis of transmission of R. parkeri to the vertebrate host. To further elucidate the role of tick feeding in rickettsial infection of vertebrates, nymphal Amblyomma maculatum Koch (Acari: Ixodidae) were fed on C3H/HeJ mice intradermally inoculated with R. parkeri (Portsmouth strain). The ticks were allowed to feed to repletion, at which time samples were taken for histopathology, immunohistochemistry (IHC), quantitative polymerase chain reaction (qPCR) for rickettsial quantification, and reverse transcriptase polymerase chain reaction(RT-PCR)for expression of Itgax, Mcp1, and Il1?. The group of mice that received intradermal inoculation of R. parkeri with tick feeding displayed significant increases in rickettsial load and IHC staining, but not in cytokine expression, when compared with the group of mice that received intradermal inoculation of R. parkeri without tick feeding. Tick feeding alone was associated with histopathologic changes in the skin, but these changes, and particularly vascular pathology, were more pronounced in the skin of mice inoculated previously with R. parkeri and followed by tick feeding. The marked differences in IHC staining and qPCR for the R. parkeri with tick feeding group strongly suggest an important role for tick feeding in the early establishment of rickettsial infection in the skin. PMID:25118419

Morgan, Timothy W.; Paddock, Christopher D.; Peterson, Karin E.; Macaluso, Kevin R.

2014-01-01

237

RC1339/APRc from Rickettsia conorii Is a Novel Aspartic Protease with Properties of Retropepsin-Like Enzymes  

Science.gov (United States)

Members of the species Rickettsia are obligate intracellular, gram-negative, arthropod-borne pathogens of humans and other mammals. The life-threatening character of diseases caused by many Rickettsia species and the lack of reliable protective vaccine against rickettsioses strengthens the importance of identifying new protein factors for the potential development of innovative therapeutic tools. Herein, we report the identification and characterization of a novel membrane-embedded retropepsin-like homologue, highly conserved in 55 Rickettsia genomes. Using R. conorii gene homologue RC1339 as our working model, we demonstrate that, despite the low overall sequence similarity to retropepsins, the gene product of rc1339 APRc (for Aspartic Protease from Rickettsia conorii) is an active enzyme with features highly reminiscent of this family of aspartic proteases, such as autolytic activity impaired by mutation of the catalytic aspartate, accumulation in the dimeric form, optimal activity at pH 6, and inhibition by specific HIV-1 protease inhibitors. Moreover, specificity preferences determined by a high-throughput profiling approach confirmed common preferences between this novel rickettsial enzyme and other aspartic proteases, both retropepsins and pepsin-like. This is the first report on a retropepsin-like protease in gram-negative intracellular bacteria such as Rickettsia, contributing to the analysis of the evolutionary relationships between the two types of aspartic proteases. Additionally, we have also shown that APRc is transcribed and translated in R. conorii and R. rickettsii and is integrated into the outer membrane of both species. Finally, we demonstrated that APRc is sufficient to catalyze the in vitro processing of two conserved high molecular weight autotransporter adhesin/invasion proteins, Sca5/OmpB and Sca0/OmpA, thereby suggesting the participation of this enzyme in a relevant proteolytic pathway in rickettsial life-cycle. As a novel bona fide member of the retropepsin family of aspartic proteases, APRc emerges as an intriguing target for therapeutic intervention against fatal rickettsioses. PMID:25144529

Cruz, Rui; Huesgen, Pitter; Riley, Sean P.; Wlodawer, Alexander; Faro, Carlos; Overall, Christopher M.; Martinez, Juan J.; Simoes, Isaura

2014-01-01

238

Epidemiology of Rickettsia sp. strain Atlantic rainforest in a spotted fever-endemic area of southern Brazil.  

Science.gov (United States)

The present study was performed in Vila Itoupava, an area of the state of Santa Catarina, southern Brazil, in which a tick-borne spotted fever illness has been endemic since 2003. Notably, both the etiological agent and the vector of these spotted fever cases remain unknown. During January 2011, humans, domestic dogs, and their ticks were sampled in households that are typically surrounded by highly preserved Atlantic rainforest fragments. Ticks collected from dogs were Amblyomma ovale (34% prevalence), Amblyomma aureolatum (18.9%), and Rhipicephalus sanguineus (3.8%). A total of 7.8% (6/77) A. ovale and 9.3% (4/43) A. aureolatum were infected by Rickettsia sp. strain Atlantic rainforest, a Rickettsia parkeri-like agent recently shown to cause spotted fever illness in southeastern Brazil. Overall, 67.3% (35/52) of the dogs were seroreactive to spotted fever group rickettsiae, mostly with highest endpoint titers to R. parkeri. Among humans, 46.7% (7/15) reacted serologically to rickettsiae at low to moderate endpoint titers. Because canine seroreactivity to R. parkeri was strongly associated with frequent contact with forests (the preferred habitat for A. ovale and A. aureolatum), it is concluded that sampled dogs have been infected by strain Atlantic rainforest through the parasitism of these tick species. The present study provides epidemiological evidence that the spotted fever in the study area has been caused by Rickettsia sp. strain Atlantic rainforest, transmitted to humans by either A. ovale or A. aureolatum. Further studies encompassing direct diagnostic methods on clinical specimens from patients are needed to confirm the above epidemiological evidence. PMID:25108786

Barbieri, Amalia R M; Filho, Jonas M; Nieri-Bastos, Fernanda A; Souza, Julio C; Szabó, Matias P J; Labruna, Marcelo B

2014-10-01

239

RC1339/APRc from Rickettsia conorii is a novel aspartic protease with properties of retropepsin-like enzymes.  

Science.gov (United States)

Members of the species Rickettsia are obligate intracellular, gram-negative, arthropod-borne pathogens of humans and other mammals. The life-threatening character of diseases caused by many Rickettsia species and the lack of reliable protective vaccine against rickettsioses strengthens the importance of identifying new protein factors for the potential development of innovative therapeutic tools. Herein, we report the identification and characterization of a novel membrane-embedded retropepsin-like homologue, highly conserved in 55 Rickettsia genomes. Using R. conorii gene homologue RC1339 as our working model, we demonstrate that, despite the low overall sequence similarity to retropepsins, the gene product of rc1339 APRc (for Aspartic Protease from Rickettsia conorii) is an active enzyme with features highly reminiscent of this family of aspartic proteases, such as autolytic activity impaired by mutation of the catalytic aspartate, accumulation in the dimeric form, optimal activity at pH 6, and inhibition by specific HIV-1 protease inhibitors. Moreover, specificity preferences determined by a high-throughput profiling approach confirmed common preferences between this novel rickettsial enzyme and other aspartic proteases, both retropepsins and pepsin-like. This is the first report on a retropepsin-like protease in gram-negative intracellular bacteria such as Rickettsia, contributing to the analysis of the evolutionary relationships between the two types of aspartic proteases. Additionally, we have also shown that APRc is transcribed and translated in R. conorii and R. rickettsii and is integrated into the outer membrane of both species. Finally, we demonstrated that APRc is sufficient to catalyze the in vitro processing of two conserved high molecular weight autotransporter adhesin/invasion proteins, Sca5/OmpB and Sca0/OmpA, thereby suggesting the participation of this enzyme in a relevant proteolytic pathway in rickettsial life-cycle. As a novel bona fide member of the retropepsin family of aspartic proteases, APRc emerges as an intriguing target for therapeutic intervention against fatal rickettsioses. PMID:25144529

Cruz, Rui; Huesgen, Pitter; Riley, Sean P; Wlodawer, Alexander; Faro, Carlos; Overall, Christopher M; Martinez, Juan J; Simões, Isaura

2014-08-01

240

Differential requirements for enriched atmospheric carbon dioxide content for intracellular growth in cell culture among selected members of the genus Rickettsia.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In an in vitro chicken embryo cell culture system, strains of Rickettsia prowazekii, R. mooseri, and R. rickettsii, but not of R. tsutsugamushi, required an atmosphere enriched in CO2 for intracellular growth.

Kopmans-gargantiel, A. I.; Wisseman, C. L.

1981-01-01

 
 
 
 
241

Identification of tlc and gltA mRNAs and determination of in situ RNA half-life in Rickettsia prowazekii.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

RNAs of Rickettsia prowazekii, an obligate intracytoplasmic bacterium, have been identified and analyzed by an RNase protection assay. Total RNA, a mixture of host cell RNA and rickettsial RNA, was isolated from rickettsia-infected mouse L929 cells by the hot-phenol method. After hybridization with specific antisense RNA probes and digestion with RNase, the protected products were analyzed by electrophoresis and autoradiography. The results show that there is only one mRNA species for the ATP...

Cai, J.; Winkler, H. H.

1993-01-01

242

Molecular detection of spotted fever group rickettsiae associated with ixodid ticks in Egypt.  

Science.gov (United States)

Tick-borne diseases comprise a complex epidemiological and ecological network that connects the vectors, pathogens, and a group of host species. The aim of this study was to identify bacteria from the genus Rickettsia associated with ixodid ticks infesting camels and cows in Egypt. Ticks were collected from 6 different localities: Qina, Giza, Qalet El Nakhl, New Valley, El Arish, and Minufia, from July to October 2008. Species were identified using PCR, followed by sequencing. The gltA and rOmpA genes were used for the initial detection of Rickettsia spp. Further characterization of positive samples utilized primers targeting rOmpB, sca4, and intergenic spacers (mppA-purC, dksA-xerC, and rpmE-tRNA(fMet)). Cows were infested with Hyalomma anatolicum excavatum and Boophilus annulatus. Camels were infested with Hyalomma dromedarii, H. impeltatum, and H. marginatum marginatum. Approximately 57.1% of H. dromedarii ticks collected from Qalet El Nakhl were infected with Rickettsia africae, exhibiting 99.1-100% identity to reference strains. Within H. impeltatum, 26.7% and 73.3% of ticks from El Arish were infected with R. africae and R. aeschlimannii, with 98.3-100% and 97.9-100% identity, respectively. Furthermore, 33.3% of H. marginatum marginatum ticks in Qalet El Nakhl were infected with the same two species as H. impeltatum, demonstrating 99.1-100% and 99.3-100% identity, respectively. By comparing percent identities and phylogenetic relationships, R. africae is identified for the first time in Egypt, in addition to R. aeschlimannii, which exhibits 100% identity with the Stavropol strain in GenBank. In conclusion, the obtained data underscore the medical and veterinary importance of tick-borne rickettsioses, which necessitate further investigation by authorities in Egypt. Moreover, additional characterization of these rickettsial isolates should be performed to designate their strains, using a polyphasic strategy combining genotypic and phenotypic tests, to facilitate their deposition in the rickettsial collection of the WHO and/or ATCC. PMID:22217182

Abdel-Shafy, Sobhy; Allam, Nesreen A T; Mediannikov, Oleg; Parola, Philippe; Raoult, Didier

2012-05-01

243

Evaluación de dos técnicas para la detección molecular de rickettsia asociada a la enfermedad del cogollo arrepollado del papayo en Cuba / Evaluation of two techniques for the molecular diagnosis of rickettsia associated to papaya bunchy top disease in Cuba  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish El objetivo de este estudio fue optimizar una técnica de diagnóstico para rickettsia-PBT, bacteria asociada a la enfermedad cogollo arrepollado del papayo (PBT), basada en la hibridación de ácidos nucleicos no radiactiva (HANS-PBT), y comparar la factibilidad de su uso con respecto a la PCR convenci [...] onal. Se optimizó un procedimiento de HANS-PBT que permitió la detección específica de hasta 15 pg de ADN del gen sdhA de rickettsia-PBT. La evaluación de 141 controles caracterizados mediante PCR convencional (PCR-PBT), mostró parámetros de desempeño de la HANS-PBT favorables, con una especificidad diagnóstica (ED) de 97,2% y sensibilidad diagnóstica (SD) de 98,5%. Los análisis simultáneos mediante las dos técnicas de 179 muestras colectadas mayormente en plantaciones del occidente de Cuba evidenciaron la presencia de rickettsia-PBT en 118 plantas. Los parámetros de desempeño de la PCR-PBT y HANS-PBT en la evaluación de estas muestras fueron similares, 96% y 98% de ED, 89% y 75% de SD, respectivamente. Aunque la HANS-PBT mostró valores de sensibilidad menores a la PCR-PBT, es factible su uso para programas de mejoramiento genético o prospecciones en estudios epidemiológicos de la diseminación de la bacteria. Abstract in english The aim of this study was to develop a technique based on non radioactive nucleic acid hybridization for the diagnosis of rickettsia-PBT bacterium associated to the papaya bunchy top disease (NASH-PBT), and to evaluate its use compared with the conventional PCR. The optimized NASH-PBT method allowed [...] the specific detection of 15 pg of sdhA gen DNA of rickettsia-PBT. The validation parameters in the evaluation of 141 controls previously characterized by PCR evidenced the reliability of the technique, showing diagnosis sensitivity (DS) of 97.2% and diagnosis specificity (DE) of 98.5%. The simultaneous analysis by the NASH-PBT and conventional PCR (PCR-PBT) of 179 samples recovered from commercial fields, mostly of the western region of Cuba, evidenced the presence of rickettsia-PBT in 118 plants. The parameters of validations of PCR-PBT and NASH-PBT in the analysis of these samples were 89% and 75% for DS and 96% and 98% for DE, respectively. Despite the lower sensibility value showed respect to NASH-PBT PCR-PBT, its use for genetic improvement programs or surveys in epidemiological studies of this pathogen is realiable.

Lester, Hernández-Rodríguez; Edel, Pérez López; Maritza, Luis Pantoja; Inés, Peña Bárzaga.

2014-08-01

244

Evaluación de dos técnicas para la detección molecular de rickettsia asociada a la enfermedad del cogollo arrepollado del papayo en Cuba / Evaluation of two techniques for the molecular diagnosis of rickettsia associated to papaya bunchy top disease in Cuba  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish El objetivo de este estudio fue optimizar una técnica de diagnóstico para rickettsia-PBT, bacteria asociada a la enfermedad cogollo arrepollado del papayo (PBT), basada en la hibridación de ácidos nucleicos no radiactiva (HANS-PBT), y comparar la factibilidad de su uso con respecto a la PCR convenci [...] onal. Se optimizó un procedimiento de HANS-PBT que permitió la detección específica de hasta 15 pg de ADN del gen sdhA de rickettsia-PBT. La evaluación de 141 controles caracterizados mediante PCR convencional (PCR-PBT), mostró parámetros de desempeño de la HANS-PBT favorables, con una especificidad diagnóstica (ED) de 97,2% y sensibilidad diagnóstica (SD) de 98,5%. Los análisis simultáneos mediante las dos técnicas de 179 muestras colectadas mayormente en plantaciones del occidente de Cuba evidenciaron la presencia de rickettsia-PBT en 118 plantas. Los parámetros de desempeño de la PCR-PBT y HANS-PBT en la evaluación de estas muestras fueron similares, 96% y 98% de ED, 89% y 75% de SD, respectivamente. Aunque la HANS-PBT mostró valores de sensibilidad menores a la PCR-PBT, es factible su uso para programas de mejoramiento genético o prospecciones en estudios epidemiológicos de la diseminación de la bacteria. Abstract in english The aim of this study was to develop a technique based on non radioactive nucleic acid hybridization for the diagnosis of rickettsia-PBT bacterium associated to the papaya bunchy top disease (NASH-PBT), and to evaluate its use compared with the conventional PCR. The optimized NASH-PBT method allowed [...] the specific detection of 15 pg of sdhA gen DNA of rickettsia-PBT. The validation parameters in the evaluation of 141 controls previously characterized by PCR evidenced the reliability of the technique, showing diagnosis sensitivity (DS) of 97.2% and diagnosis specificity (DE) of 98.5%. The simultaneous analysis by the NASH-PBT and conventional PCR (PCR-PBT) of 179 samples recovered from commercial fields, mostly of the western region of Cuba, evidenced the presence of rickettsia-PBT in 118 plants. The parameters of validations of PCR-PBT and NASH-PBT in the analysis of these samples were 89% and 75% for DS and 96% and 98% for DE, respectively. Despite the lower sensibility value showed respect to NASH-PBT PCR-PBT, its use for genetic improvement programs or surveys in epidemiological studies of this pathogen is realiable.

Lester, Hernández-Rodríguez; Edel, Pérez López; Maritza, Luis Pantoja; Inés, Peña Bárzaga.

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High Prevalence of Rickettsia africae Variants in Amblyomma variegatum Ticks from Domestic Mammals in Rural Western Kenya: Implications for Human Health.  

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Abstract Tick-borne spotted fever group (SFG) rickettsioses are emerging human diseases caused by obligate intracellular Gram-negative bacteria of the genus Rickettsia. Despite being important causes of systemic febrile illnesses in travelers returning from sub-Saharan Africa, little is known about the reservoir hosts of these pathogens. We conducted surveys for rickettsiae in domestic animals and ticks in a rural setting in western Kenya. Of the 100 serum specimens tested from each species of domestic ruminant 43% of goats, 23% of sheep, and 1% of cattle had immunoglobulin G (IgG) antibodies to the SFG rickettsiae. None of these sera were positive for IgG against typhus group rickettsiae. We detected Rickettsia africae-genotype DNA in 92.6% of adult Amblyomma variegatum ticks collected from domestic ruminants, but found no evidence of the pathogen in blood specimens from cattle, goats, or sheep. Sequencing of a subset of 21 rickettsia-positive ticks revealed R. africae variants in 95.2% (20/21) of ticks tested. Our findings show a high prevalence of R. africae variants in A. variegatum ticks in western Kenya, which may represent a low disease risk for humans. This may provide a possible explanation for the lack of African tick-bite fever cases among febrile patients in Kenya. PMID:25325312

Maina, Alice N; Jiang, Ju; Omulo, Sylvia A; Cutler, Sally J; Ade, Fredrick; Ogola, Eric; Feikin, Daniel R; Njenga, M Kariuki; Cleaveland, Sarah; Mpoke, Solomon; Ng'ang'a, Zipporah; Breiman, Robert F; Knobel, Darryn L; Richards, Allen L

2014-10-01

246

Pathologic study of mice infected with Rickettsia tsutsugamushi R19 strain.  

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Scrub typhus, an acute febrile infectious disease caused by R. tsutsugamushi, has been reported from various parts of the far east and pacific rim of Asia including Korea. It is well known that all human pathogenic rickettsia share an affinity to endothelial cells of the small blood vessels and evoke vascular inflammation variably associated with a rash, microthrombi, and hemorrhage. We infected the ICR mice by inoculating sublethal doses of R. tsutsugamushi R19 strain intraperitoneally and observed the pathologic changes by time sequence. The histopathologic features of experimentally induced scrub typhus in the mice were generally nonspecific interstitial inflammations characterized by interstitial pneumonitis, periportal inflammation, multifocal hepatic necrosis, interstitial nephritis, sinusoidal engorgement, and lymphohistiocytic cell infiltration in lymph nodes and spleen. Contrary to the general features of other rickettsial diseases, the pathologic process of scrub typhus experimentally induced by R. tsutsugamushi R19 strain mainly involved the interstitial connective tissue but not the blood vessels. PMID:8179832

Hwang, T S; Chu, Y C; Kim, Y B; Lim, B U; Kang, J S

1993-12-01

247

Analysis of convergent gene transcripts in the obligate intracellular bacterium Rickettsia prowazekii.  

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Termination of transcription is an important component of bacterial gene expression. However, little is known concerning this process in the obligate intracellular pathogen and model for reductive evolution, Rickettsia prowazekii. To assess transcriptional termination in this bacterium, transcripts of convergent gene pairs, some containing predicted intrinsic terminators, were analyzed. These analyses revealed that, rather than terminating at a specific site within the intervening region between the convergent genes, most of the transcripts demonstrated either a lack of termination within this region, which generated antisense RNA, or a putative non-site-specific termination that occurred throughout the intervening sequence. Transcripts terminating at predicted intrinsic terminators, as well as at a putative Rho-dependant terminator, were also examined and found to vary based on the rickettsial host environment. These results suggest that transcriptional termination, or lack thereof, plays a role in rickettsial gene regulation. PMID:21298070

Woodard, Andrew; Wood, David O

2011-01-01

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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

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Candidatus Rickettsia andeanae, a spotted fever group agent infecting Amblyomma parvum ticks in two Brazilian biomes  

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Full Text Available SciELO Brazil | Language: English Abstract in english Adult ticks of the species Amblyomma parvum were collected from the vegetation in the Pantanal biome (state of Mato Grosso do Sul) and from horses in the Cerrado biome (state of Piauí) in Brazil. The ticks were individually tested for rickettsial infection via polymerase chain reaction (PCR) targeti [...] ng three rickettsial genes, gltA, ompA and ompB. Overall, 63.5% (40/63) and 66.7% (2/3) of A. parvum ticks from Pantanal and Cerrado, respectively, contained rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to the corresponding fragments of the gltA, ompA and ompB genes of Candidatus Rickettsia andeanae. This report is the first to describe Ca. R. andeanae in Brazil.

Fernanda Aparecida, Nieri-Bastos; Marcos Gomes, Lopes; Paulo Henrique Duarte, Cançado; Giselle Ayres Razera, Rossa; João Luiz Horácio, Faccini; Solange Maria, Gennari; Marcelo Bahia, Labruna.

2014-04-01

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Feeding Period Required by Amblyomma aureolatum Ticks for Transmission of Rickettsia rickettsii to Vertebrate Hosts.  

Science.gov (United States)

Rocky Mountain spotted fever is endemic to the São Paulo metropolitan area, Brazil, where the etiologic agent, Rickettsia rickettsii, is transmitted to humans by adult Amblyomma aureolatum ticks. We determined the minimal feeding period required by A. aureolatum nymphs and adults to transmit R. rickettsii to guinea pigs. Unfed nymphs and unfed adult ticks had to be attached to the host for >10 hours to transmit R. rickettsii. In contrast, fed ticks needed a minimum of 10 minutes of attachment to transmit R. rickettsii to hosts. Most confirmed infections of Rocky Mountain spotted fever in humans in the São Paulo metropolitan area have been associated with contact with domestic dogs, the main host of A. aureolatum adult ticks. The typical expectation that transmission of tickborne bacteria to humans as well as to dogs requires ?2 hours of tick attachment may discourage persons from immediately removing them and result in transmission of this lethal bacterium. PMID:25148391

Saraiva, Danilo G; Soares, Herbert S; Soares, João Fábio; Labruna, Marcelo B

2014-09-01

251

Candidatus Rickettsia andeanae, a spotted fever group agent infecting Amblyomma parvum ticks in two Brazilian biomes  

Science.gov (United States)

Adult ticks of the species Amblyomma parvum were collected from the vegetation in the Pantanal biome (state of Mato Grosso do Sul) and from horses in the Cerrado biome (state of Piauí) in Brazil. The ticks were individually tested for rickettsial infection via polymerase chain reaction (PCR) targeting three rickettsial genes, gltA, ompA and ompB. Overall, 63.5% (40/63) and 66.7% (2/3) of A. parvum ticks from Pantanal and Cerrado, respectively, contained rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to the corresponding fragments of the gltA, ompA and ompB genes of Candidatus Rickettsia andeanae. This report is the first to describe Ca. R. andeanae in Brazil. PMID:24714968

Nieri-Bastos, Fernanda Aparecida; Lopes, Marcos Gomes; Cancado, Paulo Henrique Duarte; Rossa, Giselle Ayres Razera; Faccini, Joao Luiz Horacio; Gennari, Solange Maria; Labruna, Marcelo Bahia

2014-01-01

252

Candidatus Rickettsia andeanae, a spotted fever group agent infecting Amblyomma parvum ticks in two Brazilian biomes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Adult ticks of the species Amblyomma parvum were collected from the vegetation in the Pantanal biome (state of Mato Grosso do Sul) and from horses in the Cerrado biome (state of Piauí) in Brazil. The ticks were individually tested for rickettsial infection via polymerase chain reaction (PCR) targeti [...] ng three rickettsial genes, gltA, ompA and ompB. Overall, 63.5% (40/63) and 66.7% (2/3) of A. parvum ticks from Pantanal and Cerrado, respectively, contained rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to the corresponding fragments of the gltA, ompA and ompB genes of Candidatus Rickettsia andeanae. This report is the first to describe Ca. R. andeanae in Brazil.

Fernanda Aparecida, Nieri-Bastos; Marcos Gomes, Lopes; Paulo Henrique Duarte, Cançado; Giselle Ayres Razera, Rossa; João Luiz Horácio, Faccini; Solange Maria, Gennari; Marcelo Bahia, Labruna.

253

Phylogeography of Rickettsia rickettsii Genotypes Associated with Fatal Rocky Mountain Spotted Fever.  

Science.gov (United States)

Rocky Mountain spotted fever (RMSF), a tick-borne zoonosis caused by Rickettsia rickettsii, is among the deadliest of all infectious diseases. To identify the distribution of various genotypes of R. rickettsii associated with fatal RMSF, we applied molecular typing methods to samples of DNA extracted from formalin-fixed, paraffin-embedded tissue specimens obtained at autopsy from 103 case-patients from seven countries who died of RMSF. Complete sequences of one or more intergenic regions were amplified from tissues of 30 (29%) case-patients and revealed a distribution of genotypes consisting of four distinct clades, including the Hlp clade, regarded previously as a non-pathogenic strain of R. rickettsii. Distinct phylogeographic patterns were identified when composite case-patient and reference strain data were mapped to the state and country of origin. The phylogeography of R. rickettsii is likely determined by ecological and environmental factors that exist independently of the distribution of a particular tick vector. PMID:24957541

Paddock, Christopher D; Denison, Amy M; Lash, R Ryan; Liu, Lindy; Bollweg, Brigid C; Dahlgren, F Scott; Kanamura, Cristina T; Angerami, Rodrigo N; Pereira Dos Santos, Fabiana C; Brasil Martines, Roosecelis; Karpathy, Sandor E

2014-09-01

254

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 SciELO Chile | Language: Spanish 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 c [...] urativa (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 promedio 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 posit [...] ive 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 operated 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.

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

255

Two protein lysine methyltransferases methylate outer membrane protein B from Rickettsia.  

Science.gov (United States)

Rickettsia prowazekii, the etiologic agent of epidemic typhus, is a potential biological threat agent. Its outer membrane protein B (OmpB) is an immunodominant antigen and plays roles as protective envelope and as adhesins. The observation of the correlation between methylation of lysine residues in rickettsial OmpB and bacterial virulence has suggested the importance of an enzymatic system for the methylation of OmpB. However, no rickettsial lysine methyltransferase has been characterized. Bioinformatic analysis of genomic DNA sequences of Rickettsia identified putative lysine methyltransferases. The genes of the potential methyltransferases were synthesized, cloned, and expressed in Escherichia coli, and expressed proteins were purified by nickel-nitrilotriacetic acid (Ni-NTA) affinity chromatography. The methyltransferase activities of the purified proteins were analyzed by methyl incorporation of radioactively labeled S-adenosylmethionine into recombinant fragments of OmpB. Two putative recombinant methyltransferases (rRP789 and rRP027-028) methylated recombinant OmpB fragments. The specific activity of rRP789 is 10- to 30-fold higher than that of rRP027-028. Western blot analysis using specific antibodies against trimethyl lysine showed that both rRP789 and rRP027-028 catalyzed trimethylation of recombinant OmpB fragments. Liquid chromatography-tandem mass spectrometry (LC/MS-MS) analysis showed that rRP789 catalyzed mono-, di-, and trimethylation of lysine, while rRP027-028 catalyzed exclusively trimethylation. To our knowledge, rRP789 and rRP027-028 are the first biochemically characterized lysine methyltransferases of outer membrane proteins from Gram-negative bacteria. The production and characterization of rickettsial lysine methyltransferases provide new tools to investigate the mechanism of methylation of OmpB, effects of methylation on the structure and function of OmpB, and development of methylated OmpB-based diagnostic assays and vaccine candidates. PMID:23002218

Abeykoon, Amila H; Chao, Chien-Chung; Wang, Guanghui; Gucek, Marjan; Yang, David C H; Ching, Wei-Mei

2012-12-01

256

Ultrastructure of a haplosporidian containing Rickettsiae, associated with mortalities among cultured paua Haliotis iris.  

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Uninucleate and multinucleate stages of a protozoan parasite are described from cultured abalone Haliotis iris Martyn, 1784 in New Zealand. The parasite is identified as a haplosporidian by the occurrence of multinucleate plasmodia, mitochondria with tubular cristae, lipid droplets, anastomosing endoplasmic reticulum (aER), multivesicular bodies (MVBs), haplosporogenesis by the production of haplosporosome-like bodies from nuclear membrane-bound Golgi, and their maturation to haplosporosomes. Coated pits occurred in the plasma membrane and coated vesicles were scattered in the cytoplasm, particularly in association with the Golgi face away from the nucleus, and aER. It is concluded that the outward face of the Golgi may be the trans face, and that aER is the trans-Golgi network. Coated pits and bristle-coated vesicles are reported from a haplosporidian for the first time. The vesicles in the MVBs resembled the cores and inner membranes of haplosporosomes, without the outer layer. The possible inter-relationships of these features are discussed. The abalone parasite differs from previously described haplosporidians in the apparent absence of a persistent mitotic spindle, and the presence of intracytoplasmic coccoid to rod-shaped bacteria resembling Rickettsiales-like prokaryotes. Phylogenetic analysis of the 16S rRNA gene sequence of the Rickettsiales-like prokaryotes indicated that these organisms belong to the Rickettsia cluster. The prokaryotes have a high (7%) sequence divergence from known Rickettsieae, with Rickettsia sp. and R. massiliae being the closest relatives. The lack of non-molecular evidence prevents us from proposing a new rickettsial genus at this time. PMID:12113307

Hine, P M; Wakefield, S; Diggles, B K; Webb, V L; Maas, E W

2002-06-01

257

Identification of novel surface-exposed proteins of Rickettsia rickettsii by affinity purification and proteomics.  

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Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, is the most pathogenic member among Rickettsia spp. Surface-exposed proteins (SEPs) of R. rickettsii may play important roles in its pathogenesis or immunity. In this study, R. rickettsii organisms were surface-labeled with sulfo-NHS-SS-biotin and the labeled proteins were affinity-purified with streptavidin. The isolated proteins were separated by two-dimensional electrophoresis, and 10 proteins were identified among 23 protein spots by electrospray ionization tandem mass spectrometry. Five (OmpA, OmpB, GroEL, GroES, and a DNA-binding protein) of the 10 proteins were previously characterized as surface proteins of R. rickettsii. Another 5 proteins (Adr1, Adr2, OmpW, Porin_4, and TolC) were first recognized as SEPs of R. rickettsii herein. The genes encoding the 5 novel SEPs were expressed in Escherichia coli cells, resulting in 5 recombinant SEPs (rSEPs), which were used to immunize mice. After challenge with viable R. rickettsii cells, the rickettsial load in the spleen, liver, or lung of mice immunized with rAdr2 and in the lungs of mice immunized with other rSEPs excluding rTolC was significantly lower than in mice that were mock-immunized with PBS. The in vitro neutralization test revealed that sera from mice immunized with rAdr1, rAdr2, or rOmpW reduced R. rickettsii adherence to and invasion of vascular endothelial cells. The immuno-electron microscopic assay clearly showed that the novel SEPs were located in the outer and/or inner membrane of R. rickettsii. Altogether, the 5 novel SEPs identified herein might be involved in the interaction of R. rickettsii with vascular endothelial cells, and all of them except TolC were protective antigens. PMID:24950252

Gong, Wenping; Xiong, Xiaolu; Qi, Yong; Jiao, Jun; Duan, Changsong; Wen, Bohai

2014-01-01

258

The Effects of Beta Rays (Tritium) on the Growth of Rickettsiae and Influenza Virus  

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The growth of Rickettsia mooseri (murine typhus) was increased greatly in embryonate eggs containing tritium oxide at levels of 180, 90 and 45 mc/egg and slightly in eggs containing 22.5 mc/egg; the infections in those given 11.2 mc/egg did not differ from the control. The growth of Rickettsia akari (rickettsial pox) was inhibited completely in eggs containing tritium oxide at levels of 180, 90 and 45 mc/egg, and partially in groups containing 22.5 and 11.2 mc/egg. Results similar to the above were obtained following the inoculation of tritium oxide, 1 mc per 108 cells, into monoclayer cultures of KB cells infected with R. mooseri or R. akari. A decrease in the latent period for the release of influenza virus from the chorioallantoic membranes of embryonate eggs followed the injection of tritium oxide prior to infection with virus. A thousand-fold increase of virus in the chorioallantoic fluids of treated eggs was found 2 h after the inoculation of the infective agent. When detectable amounts of virus appeared in the chorioallantoic fluids of the control eggs, 8 h after infection, the ID50 of the tritium-treated eggs was 10-5,6; both series had an ID50 of 10-7.5 24 h after infection. The amounts of virus in the membranes -of the tritium-treated eggs was increased also. This virus was liberated by removing and washing the membranes, drying the membranes by vacuum sublimation at low temperatures and rupturing the cells of the membranes by rehydration with distilled water. (author)

259

Structure of fumarate hydratase from Rickettsia prowazekii, the agent of typhus and suspected relative of the mitochondria.  

Science.gov (United States)

Rickettsiae are obligate intracellular parasites of eukaryotic cells that are the causative agents responsible for spotted fever and typhus. Their small genome (about 800 protein-coding genes) is highly conserved across species and has been postulated as the ancestor of the mitochondria. No genes that are required for glycolysis are found in the Rickettsia prowazekii or mitochondrial genomes, but a complete set of genes encoding components of the tricarboxylic acid cycle and the respiratory-chain complex is found in both. A 2.4 Å resolution crystal structure of R. prowazekii fumarate hydratase, an enzyme catalyzing the third step of the tricarboxylic acid cycle pathway that ultimately converts phosphoenolpyruvate into succinyl-CoA, has been solved. A structure alignment with human mitochondrial fumarate hydratase highlights the close similarity between R. prowazekii and mitochondrial enzymes. PMID:21904061

Phan, Isabelle; Subramanian, Sandhya; Olsen, Christian; Edwards, Thomas E; Guo, Wenjin; Zhang, Yang; Van Voorhis, Wesley C; Stewart, Lance J; Myler, Peter J

2011-09-01

260

Molecular detection of hemoprotozoa and Rickettsia species in arthropods collected from wild animals in the Burgos Province, Spain  

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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...

Lledo?, Lourdes; Gime?nez-pardo, Consuelo; Domi?nguez-pen?afiel, Gerardo; Sousa, Rita; Gegu?ndez, Maria Isabep; Casado, Nieves; Criado, Angel

2010-01-01

 
 
 
 
261

Proline incorporation into protein by Rickettsia prowazekii during growth in Chinese hamster ovary (CHO-K1) cells.  

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Both the requirement of Rickettsia prowazekii for the amino acid proline for growth and rickettsial proline incorporation were determined in Chinese hamster ovary (CHO-K1) cells auxotrophic for proline. Incubation of cells in Dulbecco modified Eagle medium supplemented with various concentrations of proline resulted in a range of host intracellular proline pools, as determined by both dansylation and equilibration of specific radioactivities. Maximal rickettsial growth was observed only in ho...

Austin, F. E.; Winkler, H. H.

1988-01-01

262

Expression of the Rickettsia prowazekii pld or tlyC Gene in Salmonella enterica Serovar Typhimurium Mediates Phagosomal Escape  

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Members of the genus Rickettsia possess the ability to invade host cells and promptly escape from phagosomal vacuoles into the host cell cytosol, thereby avoiding destruction within the endosomal pathway. The mechanism underlying rickettsial phagosomal escape remains unknown, although the genomic sequences of several rickettsial species have allowed for the identification of four genes with potential membranolytic activities (tlyA, tlyC, pat1, and pld). This study was undertaken to determine ...

Whitworth, Ted; Popov, Vsevolod L.; Yu, Xue-jie; Walker, David H.; Bouyer, Donald H.

2005-01-01

263

First record of Ixodes arboricola (Ixodida: Ixodidae) from Turkey with presence of Candidatus Rickettsia vini (Rickettsiales: Rickettsiaceae).  

Science.gov (United States)

Birds are the specific hosts of many tick species and may contribute to the dissemination of ticks and tick-borne pathogens throughout the world. Determination of ticks infesting birds and their pathogens are important for the detection of natural foci of human pathogens. Unfortunately, there is very limited information about the occurrence of ticks on birds and associated pathogens in Turkey. We performed a tick survey on three passerine bird species; Parus major, Sylvia atricapilla, and Turdus merula. Ticks collected from these birds were identified to species and tested for the presence of Borrelia, Ehrlichia, and Rickettsia species. Ixodes arboricola Schulze & Schlottke, Ixodes frontalis Panzer, and Ixodes ricinus L. were found on the birds. This is the first study reporting the presence of I. frontalis and I. arboricola on S. atricapilla and P. major, respectively, in Turkey. In addition, the results of polymerase chain reaction (PCR) with primers specific for gltA and ompA genes and DNA sequence analysis of positive PCR products indicated the presence of Candidatus Rickettsia vini in I. arboricola ticks. In conclusion, this is the first record of both I. arboricola and Candidatus Rickettsia vini in Turkey. Therefore, future studies needed to be conducted on the ticks infesting birds and their pathogens to elucidate the role of birds in the dispersal of tick species and tick-borne pathogens in Turkey. PMID:25118420

Keskin, Adem; Koprulu, Tugba Kul; Bursali, Ahmet; Ozsemir, Arif Cemal; Yavuz, Kiraz Erciyas; Tekin, Saban

2014-07-01

264

Molecular characterization of Rickettsia massiliae and Anaplasma platys infecting Rhipicephalus sanguineus ticks and domestic dogs, Buenos Aires (Argentina).  

Science.gov (United States)

Rickettsioses, ehrlichioses and anaplasmoses are emerging diseases that are mainly transmitted by arthropods and that affect humans and animals. The aim of the present study was to use molecular techniques to detect and characterize those pathogens in dogs and ticks from Buenos Aires city. We studied 207 Rhipicephalus sanguineus ticks and 52 canine blood samples from poor neighborhoods of Buenos Aires city. The samples were molecularly screened for the genera Rickettsia, Ehrlichia, and Anaplasma by PCR and sequencing. DNA of Rickettsia massiliae (3.4%) and Anaplasma platys (13.5%) was detected in ticks and blood samples, respectively. For characterization, the positive samples were subjected to amplification of a fragment of the 190-kDa outer membrane protein gene (spotted fever group rickettsiae) and a fragment of the groESL gene (specific for A. platys). A phylogenetic tree was constructed using the neighbor-joining method, revealing that the sequences were closely related to those of strains from other geographic regions. The results indicate that human and animal pathogens are abundant in dogs and their ticks in Buenos Aires city and portray the potentially high risk of human exposure to infection with these agents, especially in poor neighborhoods, where there is close contact with animals in an environment of poor health conditions. PMID:24907186

Cicuttin, Gabriel L; Brambati, Diego F; Rodríguez Eugui, Juan I; Lebrero, Cecilia González; De Salvo, María N; Beltrán, Fernando J; Gury Dohmen, Federico E; Jado, Isabel; Anda, Pedro

2014-09-01

265

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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 gen [...] es 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. Abstract in english 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.

M.C., Horta; A., Pinter; A., Cortez; R.M., Soares; S.M., Gennari; T.T.S., Schumaker; M.B., Labruna.

266

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

2005-06-01

267

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

2013-05-01

268

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

269

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 SciELO Brazil | Language: English 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 gangliona [...] res 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 s [...] howed the degeneration of ganglion neurons. Dogs with chronic DCM had a secondary cardioneuropathy owing to impaired parasympathetic neural control.

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

270

Genomic, proteomic, and transcriptomic analysis of virulent and avirulent Rickettsia prowazekii reveals its adaptive mutation capabilities.  

Science.gov (United States)

Rickettsia prowazekii, the agent of epidemic typhus, is an obligate intracellular bacterium that is transmitted to human beings by the body louse. Several strains that differ considerably in virulence are recognized, but the genetic basis for these variations has remained unknown since the initial description of the avirulent vaccine strain nearly 70 yr ago. We use a recently developed murine model of epidemic typhus and transcriptomic, proteomic, and genetic techniques to identify the factors associated with virulence. We identified four phenotypes of R. prowazekii that differed in virulence, associated with the up-regulation of antiapoptotic genes or the interferon I pathway in the host cells. Transcriptional and proteomic analyses of R. prowazekii surface protein expression and protein methylation varied with virulence. By sequencing a virulent strain and using comparative genomics, we found hotspots of mutations in homopolymeric tracts of poly(A) and poly(T) in eight genes in an avirulent strain that split and inactivated these genes. These included recO, putative methyltransferase, and exported protein. Passage of the avirulent Madrid E strain in cells or in experimental animals was associated with a cascade of gene reactivations, beginning with recO, that restored the virulent phenotype. An area of genomic plasticity appears to determine virulence in R. prowazekii and represents an example of adaptive mutation for this pathogen. PMID:20368341

Bechah, Yassina; El Karkouri, Khalid; Mediannikov, Oleg; Leroy, Quentin; Pelletier, Nicolas; Robert, Catherine; Médigue, Claudine; Mege, Jean-Louis; Raoult, Didier

2010-05-01

271

A murine model of infection with Rickettsia prowazekii: implications for pathogenesis of epidemic typhus.  

Science.gov (United States)

Epidemic typhus remains a major disease threat, furthermore, its etiologic agent, Rickettsia prowazekii, is classified as a bioterrorism agent. We describe here a murine model of epidemic typhus that reproduced some features of the human disease. When BALB/c mice were inoculated intravenously with R. prowazekii (Breinl strain), they survived but did not clear R. prowazekii infection. Immunohistological analysis of tissues and quantitative PCR showed that R. prowazekii was present in blood, liver, lungs and brain 1 day after infection and persisted for at least 9 days. Importantly, infected mice developed interstitial pneumonia, with consolidation of the alveoli, hemorrhages in lungs, multifocal granulomas in liver, and hemorrhages in brain, as seen in humans. Circulating antibodies directed against R. prowazekii were detected at day 4 post-infection and steadily increased for up to 21 days, demonstrating that R. prowazekii lesions were independent of humoral immune response. R. prowazekii-induced lesions were associated with inflammatory response, as demonstrated by elevated levels of inflammatory cytokines including interferon-gamma, tumor necrosis factor and the CC chemokine RANTES in the lesions. We concluded that the BALB/c mouse strain provides a useful model for studying the pathogenic mechanisms of epidemic typhus and its control by the immune system. PMID:17537665

Bechah, Yassina; Capo, Christian; Grau, Georges E; Raoult, Didier; Mege, Jean-Louis

2007-06-01

272

Insight into the virulence of Rickettsia prowazekii by proteomic analysis and comparison with an avirulent strain.  

Science.gov (United States)

Rickettsia prowazekii, an obligate intracellular Gram-negative bacterium, is the etiologic agent of epidemic typhus. We analyzed the proteome of the virulent Breinl strain of R. prowazekii purified from infected egg yolk sacs. Total proteins from purified R. prowazekii Breinl strain were reduced by dithiothreitol, alkylated by iodoacetic acid and digested with trypsin followed by analysis with an integrated two-dimensional liquid chromatography and mass spectrometry system (2D-LC/MS/MS). A comparison was made using previously analyzed proteome of the Madrid E strain and current analysis of the Breinl strain. For Breinl 251 proteins were identified, representing 30% of the total protein-encoding genes, using a shotgun 2D-LC/MS/MS proteomic approach. This result is identical to that of Madrid E strain. Among the identified proteins, 33 from Breinl and 37 from Madrid E have an unknown function. A methyltransferase, RP028/RP027, whose gene is mutated in the avirulent Madrid E strain but not in the virulent Breinl strain, was only detectable in the Breinl strain, consistent with the genetic mutation in Madrid E. This result suggests the possible relationship between this gene product and the virulence of the strains. PMID:17301007

Chao, Chien-Chung; Chelius, Dirk; Zhang, Terry; Mutumanje, Elissa; Ching, Wei-Mei

2007-03-01

273

Directed mutagenesis of the Rickettsia prowazekii pld gene encoding phospholipase D.  

Science.gov (United States)

Rickettsia prowazekii, the causative agent of epidemic typhus, is an obligately intracytoplasmic bacterium, a lifestyle that imposes significant barriers to genetic manipulation. The key to understanding how this unique bacterium evades host immunity is the mutagenesis of selected genes hypothesized to be involved in virulence. The R. prowazekii pld gene, encoding a protein with phospholipase D activity, has been associated with phagosomal escape. To demonstrate the feasibility of site-directed knockout mutagenesis of rickettsial genes and to generate a nonrevertible vaccine strain, we utilized homologous recombination to generate a pld mutant of the virulent R. prowazekii strain Madrid Evir. Using linear DNA for transformation, a double-crossover event resulted in the replacement of the rickettsial wild-type gene with a partially deleted pld gene. Linear DNA was used to prevent potentially revertible single-crossover events resulting in plasmid insertion. Southern blot and PCR analyses were used to confirm the presence of the desired mutation and to demonstrate clonality. While no phenotypic differences were observed between the mutant and wild-type strains when grown in tissue culture, the pld mutant exhibited attenuated virulence in the guinea pig model. In addition, animals immunized with the mutant strain were protected against subsequent challenge with the virulent Breinl strain, suggesting that this transformant could serve as a nonrevertible, attenuated vaccine strain. This study demonstrates the feasibility of generating site-directed rickettsial gene mutants, providing a new tool for understanding rickettsial biology and furthering advances in the prevention of epidemic typhus. PMID:19506016

Driskell, Lonnie O; Yu, Xue-jie; Zhang, Lihong; Liu, Yan; Popov, Vsevolod L; Walker, David H; Tucker, Aimee M; Wood, David O

2009-08-01

274

Infection of endothelial cells with virulent Rickettsia prowazekii increases the transmigration of leukocytes.  

Science.gov (United States)

Rickettsia prowazekii, the etiologic agent of epidemic typhus, infects vascular endothelium, leading to vasculitis and tissue infiltration of leukocytes. Murine and human endothelial cells (ECs) were infected with R. prowazekii, including the virulent Breinl strain and the attenuated Madrid E strain. The transendothelial migration (TM) of murine and human peripheral blood mononuclear cells (PBMCs) across ECs infected with Breinl organisms was significantly increased compared with that for uninfected ECs or for ECs infected with attenuated organisms, demonstrating that increased TM was related to R. prowazekii virulence. Increased TM was associated with a specific inflammatory pattern. Indeed, only Breinl organisms induced the expression of transcripts for inflammatory cytokines and chemokines by ECs. Murine PBMCs that had transmigrated across ECs infected with Breinl organisms overexpressed inflammatory cytokines and chemokines as well as tissue factor, whereas interleukin-10 expression was down-regulated. The impact of R. prowazekii infection on the TM of PBMCs may play a prominent role in the development of lesions in epidemic typhus. PMID:18171297

Bechah, Yassina; Capo, Christian; Raoult, Didier; Mege, Jean-Louis

2008-01-01

275

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

276

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

277

La detección de Bartonella spp. y Rickettsia spp. en pulgas, garrapatas y piojos recolectados en las zonas rurales de Perú / Detection of Bartonella spp. and Rickettsia spp. in fleas, ticks and lice collected in rural areas of Peru  

Scientific Electronic Library Online (English)

Full Text Available SciELO Peru | Language: Spanish Abstract in spanish La Bartonellosis y la Rickettsiosis son enfermedades comúnmente reportadas en Perú. Con el propósito de detectar Bartonella sp. y Rickettsia sp. especímenes de pulgas, garrapatas y piojos de cinco localidades del Perú (Marizagua, Cajaruro, Jamalca, Lonya Grande and El Milagro) fueron colectadas y an [...] alizadas. Para la detección se usó PCR y una posterior confirmación con secuenciamiento de DNA. Los especímenes colectados fueron agrupados en 102 pools (76 Ctenocephalides felis, dos Ctenocephalides canis, 16Pulex irritans, cinco Pediculus humanus, dos Rhiphicephalus sanguineus, y un Boophilus spp.). Bartonella fue detectada en 17 pools (seis de C. felis, nueve de P. irritans, uno de C. canis, y uno de P. humanus). Rickettsia fue detectada en 76 pools (62 de C. felis, 10 de P. irritans, dos de P. humanus, y dos de C. canis). Bartonella clarridgeiae fue detectada en C. felis (5.3% especímenes), C. canis (50%) y P. irritans (12.5%). Bartonella rochalimae fue detectada en C. felis (1.3%) y P. irritans (12.5%). Además, se detectó B. henselae en C. felis (1.3%) y P. humanus (20%). Bartonella spp. también se encontró en P. irritans (31,3%). Además, se detectó R. felis en C. felis (76.3%), C. canis (100%) y P. irritans (37.5%), y Rickettsia spp. se detectó en C. felis (5,3%), P. irritans (25%) y P. humanus (40%). Estos resultados demuestran la circulación de estas bacterias en el Perú Abstract in english Bartonellosis and rickettsiosis are commonly reported in Peru. In order to detect Bartonella sp. and Rickettsia sp. in fleas, ticks and lice, specimens from five distinct locations in Peru (Marizagua, Cajaruro, Jamalca, Lonya Grande and El Milagro) were collected and screened for the presence of the [...] se bacteria using PCR and later confirmation by DNA sequencing. The specimens collected were distributed in 102 pools (76 Ctenocephalides felis, 2 Ctenocephalides canis, 16Pulex irritans, 5 Pediculus humanus, 2 Rhiphicephalus sanguineus, and 1 Boophilus spp.), whereBartonella was detected in 17 pools (6 of C. felis, 9 of P. irritans, 1 of C. canis, and 1 P. humanus). Also, Rickettsia was detected in 76 pools (62 C. felis, 10 P. irritans, 2 P. humanus, and 2 C. canis). Bartonella clarridgeiae was detected in C. felis, C. canis and P. irritans pools at 5.3%, 50% and 12.5%, respectively. Bartonella rochalimae was detected in one C. felis and two P. irritans pools at 1.3% and 12.5%, respectively. Furthermore, B. henselae was detected in one C. felis pool and one P. humanus pool corresponding to 1.3% and 20%, respectively; andBartonella spp. was also found in 5 pools of P. irritans at 31.3%. Additionally, R. felis was detected in C. felis, C. canis and P. irritans pools at 76.3%, 100% and 37.5%, respectively; and Rickettsia spp. was detected in C. felis, P. irritans and P. humanus pools at 5.3%, 25% and 40%, respectively. These results demonstrate the circulation of these bacteria in Peru

Abraham G, Cáceres; Carlos P, Padilla Rojas; Javier, Arias Stella; Gerardo, Huatuco Crisanto; Antero, Gonzales Pérez.

278

Prevalence of Rickettsia felis in the fleas Ctenocephalides felis felis and Ctenocephalides canis from two Indian villages in Sao Paulo Municipality, Brazil.  

Science.gov (United States)

We evaluated the presence of Rickettsia infection among fleas collected on domestic dogs in two Guarani Indian communities in the suburban area of São Paulo Municipality, Brazil. A total of 114 Ctenocephalides felis felis and 47 Ctenocephalides canis were collected from 40 dogs. A total of 41 C. felis felis (36.0%) and 9 C. canis (19.1%) fleas yielded expected bands by PCR, which were all shown by DNA sequencing to be indentical to the corresponding sequence of a fragment of the Rickettsia felis gltA gene deposited in GenBank. The overall prevalence of R. felis was 31.0% (49/161). PMID:17114741

Horta, Mauricio C; Chiebao, Daniela P; de Souza, Daniele B; Ferreira, Fernando; Pinheiro, Sônia R; Labruna, Macelo B; Schumaker, Teresinha T S

2006-10-01

279

Synthesis of DNA, rRNA, and protein by Rickettsia prowazekii growing in untreated or gamma interferon-treated mouse L929 cells.  

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The syntheses of DNA, rRNA, and protein by Rickettsia prowazekii growing in mouse fibroblastic L929 cells were measured at various times after the addition of gamma interferon (IFN-gamma) to correlate the inhibition of a site of macromolecular synthesis with the established IFN-gamma-induced inhibition of rickettsial growth. A method was developed to measure the syntheses of DNA, rRNA, and protein by R. prowazekii during a 2-h pulse-labeling period while the rickettsiae were growing within cu...

Gao, Q.; Turco, J.; Winkler, H. H.

1993-01-01

280

Diversity of babesia and rickettsia species in questing ixodes ricinus: a longitudinal study in urban, pasture, and natural habitats.  

Science.gov (United States)

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

2013-08-01

 
 
 
 
281

Guías Latinoamericanas de la RIICER para el diagnóstico de las rickettsiosis transmitidas por garrapatas / Latinamerican guidelines of RIICER for diagnosis of tick-borne rickettsioses  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Las rickettsiosis transmitidas por garrapatas son afecciones de distribución mundial, que por diferentes motivos se pueden considerar emergentes y reemergentes. Hasta hace escasos años la única rickettsiosis transmitida por garrapatas en Latinoamérica era la infección por Rickettsia rickettsii, pero [...] en la actualidad y fundamentalmente, gracias a la incorporación de nuevas herramientas para el diagnóstico microbiológico como la reacción en cadena de la polimerasa y secuenciación o el cultivo celular rápido en tubo cerrado, se han descrito e involucrado otras especies de Rickettsia en la producción de patología humana. En estas guías se detallan y describen las diferentes técnicas utilizadas para el diagnóstico microbiológico de las rickettsiosis. Además, se incluye una sección en la que se detallan las especies más importantes de garrapatas duras relacionadas con las rickettsiosis en Latinoamérica, con claves para su clasificación taxonómica. Abstract in english Tick-borne rickettsioses are worldwide infectious diseases that are considered emerging and re-emerging. Until recently the only tick-borne rickettsiosis present in Latin America was Rickettsia rickettsii infection, but to date, with the incorporation of new tools as PCR and sequencing and the quick [...] cellular close tube cultures (Shell-vial), new species has been involved as human pathogens. In these guidelines, we offer an update of the microbiological assays for diagnosing rickettsioses. Besides we have included a section in which the most important hard ticks involved in human rickettsioses in Latinoamerica are detailed.

José A, Oteo; Santiago, Nava; Rita de, Sousa; Salim, Mattar; José M, Venzal; Katia, Abarca; Marcelo B, Labruna; Jorge, Zavala-Castro.

2014-02-01

282

A Molecular Survey of Rickettsia felis in Fleas from Cats and Dogs in Sicily (Southern Italy)  

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Rickettsia felis, the agent of flea-borne spotted fever, has a cosmopolitan distribution. Its pathogenic role in humans has been demonstrated through molecular and serologic tests in several cases. The cat flea (Ctenocephalides felis) is considered the main reservoir and the biological vector. The aim of this study was to assess the presence and occurrence of R. felis in fleas collected from dogs and cats in various sites of Palermo (Sicily). Between August and October 2012, 134 fleas were collected from 42 animals: 37 fleas from 13 dogs and 97 fleas from 29 cats. Two species of fleas were identified: 132 Ctenocephalides felis (98.51%) collected on all animals and only two C. canis (1.49%) on one dog. Out of 132 C. felis, 34 (25.76%), 12 from dogs (32.43%) and 22 (22.68%) from cats, were positive for R. felis DNA by a polymerase chain reaction (PCR), confirmed by sequencing. The only two C. canis fleas were negative. About half of examined animals (47.62%, 20/42) were infested with at least one infected flea; in particular 46.15% of dogs (6/13) and 48.28% of cats (14/29). It seems that in the Palermo district there is a peri-domestic cycle, with a relatively high prevalence of R. felis infection in the cat flea, an insect widely diffused in home environments and which can frequently bite humans. The results also suggest that R. felis should be considered in the human differential diagnosis of any spotted-like fever or febrile illness without a clear source of infection in Sicily, especially if the patient is known to have been exposed to flea bites. PMID:25203839

Giudice, Elisabetta; Di Pietro, Simona; Alaimo, Antonio; Blanda, Valeria; Lelli, Rossella; Francaviglia, Francesco; Caracappa, Santo; Torina, Alessandra

2014-01-01

283

Rickettsia parkeri invasion of diverse host cells involves an Arp2/3 complex, WAVE complex and Rho-family GTPase-dependent pathway.  

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Rickettsiae are obligate intracellular pathogens that are transmitted to humans by arthropod vectors and cause diseases such as spotted fever and typhus. Although rickettsiae require the host cell actin cytoskeleton for invasion, the cytoskeletal proteins that mediate this process have not been completely described. To identify the host factors important during cell invasion by Rickettsia parkeri, a member of the spotted fever group (SFG), we performed an RNAi screen targeting 105 proteins in Drosophila melanogaster S2R+ cells. The screen identified 21 core proteins important for invasion, including the GTPases Rac1 and Rac2, the WAVE nucleation-promoting factor complex and the Arp2/3 complex. In mammalian cells, including endothelial cells, the natural targets of R. parkeri, the Arp2/3 complex was also crucial for invasion, while requirements for WAVE2 as well as Rho GTPases depended on the particular cell type. We propose that R. parkeri invades S2R+ arthropod cells through a primary pathway leading to actin nucleation, whereas invasion of mammalian endothelial cells occurs via redundant pathways that converge on the host Arp2/3 complex. Our results reveal a key role for the WAVE and Arp2/3 complexes, as well as a higher degree of variation than previously appreciated in actin nucleation pathways activated during Rickettsia invasion. PMID:22188208

Reed, Shawna C O; Serio, Alisa W; Welch, Matthew D

2012-04-01

284

Retrospective Clinical and Molecular Analysis of Conditioned Laboratory Dogs (Canis familiaris) with Serologic Reactions to Ehrlichia canis, Borrelia burgdorferi, and Rickettsia rickettsii  

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Dogs are susceptible to different tickborne infections, including members of the Anaplasmataceae (Ehrlichia canis, E. ewingii, E. chaffeensis, Anaplasma phagocytophilum, A. platys), Borrelia burgdorferi, and Rickettsia rickettsii. These diseases can manifest with clinical signs including fever, anorexia, malaise, lameness, rash, and bleeding episodes; however, these signs are nonpathognomonic, and infections can occur in the absence of clinical signs. Hematologic abnormalities can include leu...

Scorpio, Diana G.; Wachtman, Lynn M.; Tunin, Richard S.; Barat, Nicole C.; Garyu, Justin W.; Dumler, J. Stephen

2008-01-01

285

Distribution and infection frequency of 'Candidatus Rickettsia amblyommii' in Maryland populations of the lone star tick (Amblyomma americanum) and culture in an Anopheles gambiae mosquito cell line.  

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Amblyomma americanum (the lone star tick) is a broadly distributed tick that transmits multiple pathogens of humans and domestic animals. 'Candidatus Rickettsia amblyommii' is a spotted-fever group rickettsial species that is potentially associated with human disease. In 2008 and 2009, we assayed over 500 unfed adult ticks from 19 Maryland populations for the presence of 'Candidatus R. amblyommii'. Infection frequencies ranged from 33% to 100%, with an average infection rate of 60% in 2008 and 69% in 2009. Infection frequencies did not differ statistically between sexes. To develop a system in which to study 'Candidatus R. amblyommii' in the laboratory, we used a cell line developed from Anopheles gambiae mosquitoes (Sua5B) to isolate and culture 'Candidatus R. amblyommii' from field-collected A. americanum ticks from 2 localities in Maryland. After infection, Sua5B cells were infected for more than 40 passages. Infection was confirmed by Rickettsia-specific PCR, gene sequencing, and Rickettsia-specific fluorescence in situ hybridization (FISH). These data show that 'Candidatus R. amblyommii' is widespread in Maryland A. americanum populations and that Sua5B cells are a useful tool for culturing Rickettsia infections from wild ticks. PMID:22309857

Zhang, Xing; Ren, Xiaoxia; Norris, Douglas E; Rasgon, Jason L

2012-02-01

286

A protein from a parasitic microorganism, Rickettsia prowazekii, can cleave the signal sequences of proteins targeting mitochondria.  

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The obligate intracellular parasitic bacteria rickettsiae are more closely related to mitochondria than any other microbes investigated to date. A rickettsial putative peptidase (RPP) was found to resemble the alpha and beta subunits of mitochondrial processing peptidase (MPP), which cleaves the transport signal sequences of mitochondrial preproteins. RPP showed completely conserved zinc-binding and catalytic residues compared with beta-MPP but barely contained any of the glycine-rich loop region characteristic of alpha-MPP. When the biochemical activity of RPP purified from a recombinant source was analyzed, RPP specifically hydrolyzed basic peptides and presequence peptides with frequent cleavage at their MPP-processing sites. Moreover, RPP appeared to activate yeast beta-MPP so that it processed preproteins with shorter presequences. Thus, RPP behaves as a bifunctional protein that could act as a basic peptide peptidase and a somewhat regulatory protein for other protein activities in rickettsiae. These are the first biological and enzymological studies to report that a protein from a parasitic microorganism can cleave the signal sequences of proteins targeted to mitochondria. PMID:17158683

Kitada, Sakae; Uchiyama, Tsuneo; Funatsu, Tomoyuki; Kitada, Yumiko; Ogishima, Tadashi; Ito, Akio

2007-02-01

287

Dual mechanisms of metabolite acquisition by the obligate intracytosolic pathogen Rickettsia prowazekii reveal novel aspects of triose phosphate transport.  

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Rickettsia prowazekii is an obligate intracytosolic pathogen and the causative agent of epidemic typhus fever in humans. As an evolutionary model of intracellular pathogenesis, rickettsiae are notorious for their use of transport systems that parasitize eukaryotic host cell biochemical pathways. Rickettsial transport systems for substrates found only in eukaryotic cell cytoplasm are uncommon among free-living microorganisms and often possess distinctive mechanisms. We previously reported that R. prowazekii acquires triose phosphates for phospholipid biosynthesis via the coordinated activities of a novel dihydroxyacetone phosphate transport system and an sn-glycerol-3-phosphate dehydrogenase (K. M. Frohlich et al., J. Bacteriol. 192:4281-4288, 2010). In the present study, we have determined that R. prowazekii utilizes a second, independent triose phosphate acquisition pathway whereby sn-glycerol-3-phosphate is directly transported and incorporated into phospholipids. Herein we describe the sn-glycerol-3-phosphate and dihydroxyacetone phosphate transport systems in isolated R. prowazekii with respect to kinetics, energy coupling, transport mechanisms, and substrate specificity. These data suggest the existence of multiple rickettsial triose phosphate transport systems. Furthermore, the R. prowazekii dihydroxyacetone phosphate transport systems displayed unexpected mechanistic properties compared to well-characterized triose phosphate transport systems from plant plastids. Questions regarding possible roles for dual-substrate acquisition pathways as metabolic virulence factors in the context of a pathogen undergoing reductive evolution are discussed. PMID:23772074

Frohlich, Kyla M; Audia, Jonathon P

2013-08-01

288

Structure of 3-ketoacyl-(acyl-carrier-protein) reductase from Rickettsia prowazekii at 2.25 Å resolution.  

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Rickettsia prowazekii, a parasitic Gram-negative bacterium, is in the second-highest biodefense category of pathogens of the National Institute of Allergy and Infectious Diseases, but only a handful of structures have been deposited in the PDB for this bacterium; to date, all of these have been solved by the SSGCID. Owing to its small genome (about 800 protein-coding genes), it relies on the host for many basic biosynthetic processes, hindering the identification of potential antipathogenic drug targets. However, like many bacteria and plants, its metabolism does depend upon the type II fatty-acid synthesis (FAS) pathway for lipogenesis, whereas the predominant form of fatty-acid biosynthesis in humans is via the type I pathway. Here, the structure of the third enzyme in the FAS pathway, 3-ketoacyl-(acyl-carrier-protein) reductase, is reported at a resolution of 2.25 Å. Its fold is highly similar to those of the existing structures from some well characterized pathogens, such as Mycobacterium tuberculosis and Burkholderia pseudomallei, but differs significantly from the analogous mammalian structure. Hence, drugs known to target the enzymes of pathogenic bacteria may serve as potential leads against Rickettsia, which is responsible for spotted fever and typhus and is found throughout the world. PMID:21904060

Subramanian, Sandhya; Abendroth, Jan; Phan, Isabelle Q H; Olsen, Christian; Staker, Bart L; Napuli, A; Van Voorhis, Wesley C; Stacy, Robin; Myler, Peter J

2011-09-01

289

SNP-based real-time pyrosequencing as a sensitive and specific tool for identification and differentiation of Rickettsia species in Ixodes ricinus ticks  

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Full Text Available Abstract Background Rickettsioses are caused by pathogenic species of the genus Rickettsia and play an important role as emerging diseases. The bacteria are transmitted to mammal hosts including humans by arthropod vectors. Since detection, especially in tick vectors, is usually based on PCR with genus-specific primers to include different occurring Rickettsia species, subsequent species identification is mainly achieved by Sanger sequencing. In the present study a real-time pyrosequencing approach was established with the objective to differentiate between species occurring in German Ixodes ticks, which are R. helvetica, R. monacensis, R. massiliae, and R. felis. Tick material from a quantitative real-time PCR (qPCR based study on Rickettsia-infections in I. ricinus allowed direct comparison of both sequencing techniques, Sanger and real-time pyrosequencing. Methods A sequence stretch of rickettsial citrate synthase (gltA gene was identified to contain divergent single nucleotide polymorphism (SNP sites suitable for Rickettsia species differentiation. Positive control plasmids inserting the respective target sequence of each Rickettsia species of interest were constructed for initial establishment of the real-time pyrosequencing approach using Qiagen’s PSQ 96MA Pyrosequencing System operating in a 96-well format. The approach included an initial amplification reaction followed by the actual pyrosequencing, which is traceable by pyrograms in real-time. Afterwards, real-time pyrosequencing was applied to 263 Ixodes tick samples already detected Rickettsia-positive in previous qPCR experiments. Results Establishment of real-time pyrosequencing using positive control plasmids resulted in accurate detection of all SNPs in all included Rickettsia species. The method was then applied to 263 Rickettsia-positive Ixodes ricinus samples, of which 153 (58.2% could be identified for their species (151 R. helvetica and 2 R. monacensis by previous custom Sanger sequencing. Real-time pyrosequencing identified all Sanger-determined ticks as well as 35 previously undifferentiated ticks resulting in a total number of 188 (71.5% identified samples. Pyrosequencing sensitivity was found to be strongly dependent on gltA copy numbers in the reaction setup. Whereas less than 101 copies in the initial amplification reaction resulted in identification of 15.1% of the samples only, the percentage increased to 54.2% at 101-102 copies, to 95.6% at >102-103 copies and reached 100% samples identified for their Rickettsia species if more than 103 copies were present in the template. Conclusions The established real-time pyrosequencing approach represents a reliable method for detection and differentiation of Rickettsia spp. present in I. ricinus diagnostic material and prevalence studies. Furthermore, the method proved to be faster, more cost-effective as well as more sensitive than custom Sanger sequencing with simultaneous high specificity.

Janecek Elisabeth

2012-10-01

290

In vitro susceptibilities of Bartonella henselae, B. quintana, B. elizabethae, Rickettsia rickettsii, R. conorii, R. akari, and R. prowazekii to macrolide antibiotics as determined by immunofluorescent-antibody analysis of infected Vero cell monolayers.  

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The in vitro susceptibilities of Bartonella (Rochalimaea) henselae, B. quintana, B. elizabethae, Rickettsia akari, R. conorii, R. prowazekii, and R. rickettsii to different concentrations of azithromycin, clarithromycin, dirithromycin, erythromycin, and roxithromycin in Vero cell cultures were evaluated. Bartonella and Rickettsia spp. were allowed to initiate infection of the antibiotic-free Vero cell monolayers, which were maintained in 16-chamber microscope slides in the absence of antibiot...

Ives, T. J.; Manzewitsch, P.; Regnery, R. L.; Butts, J. D.; Kebede, M.

1997-01-01

291

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

2007-12-01

292

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish 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 relacion [...] a 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. Abstract in english 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 t [...] hat 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.

2007-12-01

293

Effect of forest fragmentation on tick infestations of birds and tick infection rates by rickettsia in the Atlantic forest of Brazil.  

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Habitat loss and modifications affect biodiversity, potentially contributing to outbreaks of infectious diseases. We evaluated if the patch sizeinfragmented areas of Atlantic Forest in southeastern Brazil influences the diversity of forest birds and consequently the prevalence of ticks on birds and the rickettsial infection of these ticks. During 2 years, we collected ticks from birds in 12 sites: four small forest patches (80-140 ha), four large ones (480-1,850 ha), and four forest control areas within the much larger Morro do Diabo State Park (approximately 36,000 ha). A total of 1,725 birds were captured (81 species, 24 families), from which 223 birds were infested by 2,339 ticks of the genus Amblyomma, mostly by the species A. nodosum. Bird diversity and richness were higher in larger than smaller forest fragments. The prevalence of ticks on birds was inversely correlated with bird diversity and richness. Among 174 A. nodosum tested for rickettsial infection by polymerase chain reaction, 51 were found to be infected by Rickettsia bellii or Rickettsia parkeri. However, tick infection rates by Rickettsia spp. were not statistically different between forest patch sizes. The higher prevalence of ticks on birds in degraded patches might be caused by a dominance of a few generalist bird species in small patches, allowing an easier transmission of parasites among individuals. It could also be related to more favorable microclimatic conditions for the free-living stages of A. nodosum in smaller forest fragments.The higher burden of ticks on birds in smaller forest fragments is an important secondary effect of habitat fragmentation, possibly increasing the likelihood of Rickettsia contagion. PMID:22173291

Ogrzewalska, Maria; Uezu, Alexandre; Jenkins, Clinton N; Labruna, Marcelo B

2011-09-01

294

Rickettsia prowazekii Uses an sn-Glycerol-3-Phosphate Dehydrogenase and a Novel Dihydroxyacetone Phosphate Transport System To Supply Triose Phosphate for Phospholipid Biosynthesis ?  

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Rickettsia prowazekii is an obligate intracellular pathogen that possesses a small genome and a highly refined repertoire of biochemical pathways compared to those of free-living bacteria. Here we describe a novel biochemical pathway that relies on rickettsial transport of host cytosolic dihydroxyacetone phosphate (DHAP) and its subsequent conversion to sn-glycerol-3-phosphate (G3P) for synthesis of phospholipids. This rickettsial pathway compensates for the evolutionary loss of rickettsial g...

Frohlich, Kyla M.; Roberts, Rosemary A. W.; Housley, Nicole A.; Audia, Jonathon P.

2010-01-01

295

Transcriptional regulation of the gltA and tlc genes in Rickettsia prowazekii growing in a respiration-deficient host cell  

International Nuclear Information System (INIS)

The regulation of the citrate synthase (gltA) and ATP/ADP translocase (tlc) genes of the obligate intracellular bacterium, Rickettsia prowazekii, was analyzed in rickettsia-infected respiration-deficient G14 cells. The level of the gltA mRNAII and the tlc mRNA was much lower in the total RNA isolated from the infected G 14 cells grown in 1 g/1 glucose (low glucose, GL) medium than in that from infected G 14 cells grown in 4.5 g/l glucose (high glucose, GH) medium. However, the level of the gltA mRNAI relative to 16 S rRNA was the same in GL and GH media. An increase in the level of the gltA mRNAII and the tlc mRNA could be observed as early as 2 hrs after shifting from GL to GH medium. We conclude that, under these experimental conditions, the tlc promoter and the gltA promoter P2, but not gltA promoter P1, were transcriptionally regulated. Key words: Rickettsia prowazekii; gltA gene; tlC gene; transcriptional regulation; G 14 cells (authors)

296

Discovery of a protective Rickettsia prowazekii antigen recognized by CD8+ T cells, RP884, using an in vivo screening platform.  

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Rickettsia prowazekii has been tested for biological warfare due to the high mortality that it produces after aerosol transmission of very low numbers of rickettsiae. Epidemic typhus, the infection caused by these obligately intracellular bacteria, continues to be a threat because it is difficult to diagnose due to initial non-specific symptoms and the lack of commercial diagnostic tests that are sensitive and specific during the initial clinical presentation. A vaccine to prevent epidemic typhus would constitute an effective deterrent to the weaponization of R. prowazekii; however, an effective and safe vaccine is not currently available. Due to the cytoplasmic niche of Rickettsia, CD8(+) T-cells are critical effectors of immunity; however, the identification of antigens recognized by these cells has not been systematically addressed. To help close this gap, we designed an antigen discovery strategy that uses cell-based vaccination with antigen presenting cells expressing microbe's proteins targeted to the MHC class I presentation pathway. We report the use of this method to discover a protective T-cell rickettsial antigen, RP884, among a test subset of rickettsial proteins. PMID:24146844

Gazi, Michal; Caro-Gomez, Erika; Goez, Yenny; Cespedes, Maria A; Hidalgo, Marylin; Correa, Paula; Valbuena, Gustavo

2013-01-01

297

Rapid, simple, and sensitive detection of the ompB gene of spotted fever group rickettsiae by loop-mediated isothermal amplification  

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Full Text Available Abstract Background Spotted fever caused spotted fever group rickettsiae (SFGR is prevalent throughout China. In this study, we describe a rapid, simple, and sensitive loop-mediated isothermal amplification (LAMP assay targeting the ompB gene of spotted fever group rickettsiae ideal for application in China. The LAMP assay has the potential to detect spotted fever group rickettsiae early in infection and could therefore serve as an alternative to existing methods. Methods A set of universal primers which are specific 7 common species of spotted fever group rickettsiae in China were designed using PrimerExplorer V4 software based on conserved sequences of ompB gene. The sensitivity, specificity and reproducibility of the LAMP were evaluated. The LAMP assay for detecting SFGR was compared with conventional PCR assays for sensitivity and specificity in early phase blood samples obtained from 11 infected human subjects. Results The sensitivity of the LAMP assay was five copies per reaction (25 ?L total volume, and the assay did not detect false-positive amplification across 42 strains of 27 members of the order Rickettsiales and 17 common clinical pathogens. The LAMP assay was negative to typhus group rickettsiae including R. prowazekii and R. typhi for no available conserved sequences of ompB was obtained for designing primers. To evaluate the clinical applicability of the LAMP assay, a total of 11 clinical samples, 10 samples confirmed serologically (3 cases, ecologically (1 case, by real-time polymerase chain reaction (PCR; 2 cases, ecologically and by real-time PCR (1 case, and serologically and by real-time PCR (3 cases were analyzed by the ompB LAMP assay. Data were validated using a previously established nested PCR protocol and real-time PCR. A positive LAMP result was obtained for 8 of the 10 confirmed cases (sensitivity, 73%; specificity, 100%, while none of these samples were positive by nested PCR (sensitivity, 0%; specificity, 100%. Conclusions The LAMP assay described here is the most reliable among the three methods tested and would be an ideal choice for development as a rapid and cost-effective means of detecting SFGR in China.

Pan Lei

2012-10-01

298

Análisis de las recidivas locorregionales por cáncer de mama / Analysis of locoregional relapses from breast cancer  

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Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish 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 op [...] eradas. 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. Abstract in english 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 fr [...] om 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.

2012-12-01

299

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

2012-12-01

300

Occurrence of Babesia spp., Rickettsia spp. and Bartonella spp. in Ixodes ricinus in Bavarian public parks, Germany  

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Full Text Available Abstract Background Only limited information is available about the occurrence of ticks and tick-borne pathogens in public parks, which are areas strongly influenced by human beings. For this reason, Ixodes ricinus were collected in public parks of different Bavarian cities in a 2-year survey (2009 and 2010 and screened for DNA of Babesia spp., Rickettsia spp. and Bartonella spp. by PCR. Species identification was performed by sequence analysis and alignment with existing sequences in GenBank. Additionally, coinfections with Anaplasma phagocytophilum were investigated. Results The following prevalences were detected: Babesia spp.: 0.4% (n = 17, including one pool of two larvae in 2009 and 0.5 to 0.7% (n = 11, including one pool of five larvae in 2010; Rickettsia spp.: 6.4 to 7.7% (n = 285, including 16 pools of 76 larvae in 2009. DNA of Bartonella spp. in I. ricinus in Bavarian public parks could not be identified. Sequence analysis revealed the following species: Babesia sp. EU1 (n = 25, B. divergens (n = 1, B. divergens/capreoli (n = 1, B. gibsoni-like (n = 1, R. helvetica (n = 272, R. monacensis IrR/Munich (n = 12 and unspecified R. monacensis (n = 1. The majority of coinfections were R. helvetica with A. phagocytophilum (n = 27, but coinfections between Babesia spp. and A. phagocytophilum, or Babesia spp. and R. helvetica were also detected. Conclusions I. ricinus ticks in urban areas of Germany harbor several tick-borne pathogens and coinfections were also observed. Public parks are of particularly great interest regarding the epidemiology of tick-borne pathogens, because of differences in both the prevalence of pathogens in ticks as well as a varying species arrangement when compared to woodland areas. The record of DNA of a Babesia gibsoni-like pathogen detected in I. ricinus suggests that I. ricinus may harbor and transmit more Babesia spp. than previously known. Because of their high recreational value for human beings, urban green areas are likely to remain in the research focus on public health issues.

Mahling Monia

2011-07-01

 
 
 
 
301

Anticorpos anti-rickettsias do grupo da febre maculosa em equídeos e caninos no norte do Estado do Paraná, Brasil Anti rickettsia-antibody for spotted fever group in horses and dogs in the North of Paraná Stated, Brazil  

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Full Text Available The Brazilian Spotted Fever (BSF is a zoonosis that can be fatal if not trteated. As there are few studies of the BSF in the Paraná State, the occurrence of BSF was serologically investigated in dogs and horses by indirect immunofluorescence assay (IFA, in the North of that State, in animals that are regarded as sentinels for BSF. A total of 241 samples of sera of equine, four of asinine, and 29 of dogs were collected in nine farms of three municipalities in the North of Paraná: Arapongas, Douradina, and Umuarama. From fifteen samples of equine serum with positive titres for RIFI, eight (53.3 % had titre of 64 against R. rickettsii, two (13.3 % 128 against R. rickettsii, and five (33.3 % were reactants for R. parkeri and R. rickettsii, with titres ranging from 64 to 2048, and 128 to 1024, respectively. The results showed that domestic animals, sentinels for BSF, are under low exposition to ticks infected with spotted fever group Rickettsia, indicating low risk of human infection by these agents in the studied area.

F.H. Otomura

2010-06-01

302

'Candidatus Megaira polyxenophila' gen. nov., sp. nov.: considerations on evolutionary history, host range and shift of early divergent rickettsiae.  

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"Neglected Rickettsiaceae" (i.e. those harboured by non-hematophagous eukaryotic hosts) display greater phylogenetic variability and more widespread dispersal than pathogenic ones; yet, the knowledge about their actual host range and host shift mechanism is scarce. The present work reports the characterization following the full-cycle rRNA approach (SSU rRNA sequence, specific in situ hybridization, and ultrastructure) of a novel rickettsial bacterium, herewith proposed as 'Candidatus Megaira polyxenophila' gen. nov., sp. nov. We found it in association with four different free-living ciliates (Diophrys oligothrix, Euplotes octocarinatus, Paramecium caudatum, and Spirostomum sp., all belonging to Alveolata, Ciliophora); furthermore it was recently observed as intracellular occurring in Carteria cerasiformis and Pleodorina japonica (Chlorophyceae, Chlorophyta). Phylogenetic analyses demonstrated the belonging of the candidate new genus to the family Rickettsiaceae (Alphaproteobacteria, Rickettsiales) as a sister group of the genus Rickettsia. In situ observations revealed the ability of the candidate new species to colonize either nuclear or cytoplasmic compartments, depending on the host organism. The presence of the same bacterial species within different, evolutionary distant, hosts indicates that 'Candidatus Megaira polyxenophila' recently underwent several distinct host shifts, thus suggesting the existence of horizontal transmission pathways. We consider these findings as indicative of an unexpected spread of rickettsial infections in aquatic communities, possibly by means of trophic interactions, and hence propose a new interpretation of the origin and phylogenetic diversification of rickettsial bacteria. PMID:23977321

Schrallhammer, Martina; Ferrantini, Filippo; Vannini, Claudia; Galati, Stefano; Schweikert, Michael; Görtz, Hans-Dieter; Verni, Franco; Petroni, Giulio

2013-01-01

303

Molecular identification of Rickettsia parkeri infecting Amblyomma triste ticks in an area of Argentina where cases of rickettsiosis were diagnosed  

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Full Text Available SciELO Brazil | Language: English Abstract in english Specimens of the hard tick Amblyomma triste were found infected with Rickettsia parkeri in an area of Argentina (General Lavalle, Buenos Aires Province) where cases of human illness attributed to this microorganism have been reported. Molecular detection of R. parkeri was based on polymerase chain r [...] eactions that amplify a ca. 400-bp fragment of the 23S-5S intergenic spacer and a ca. 500-bp fragment of the gene encoding a 190-kDa outer membrane protein. Three (6.97%) of 43 A. triste ticks were determined to be positive for R. parkeri. These results provide strong evidence that A. triste is the vector of R. parkeri in the study area. The findings of this work have epidemiological relevance because human parasitism by A. triste ticks has been frequently recorded in some riparian areas of Argentina and Uruguay and new cases of R. parkeri rickettsiosis might arise in the South American localities where humans are exposed to the bites of this tick species.

Gabriel, Cicuttin; Santiago, Nava.

2013-02-01

304

Dual exposure of Rickettsia typhi and Orientia tsutsugamushi in the field-collected Rattus rodents from Thailand.  

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Field-collected rodents and fleas from ten provinces covering four regions of Thailand were investigated for possible rickettsial pathogen infections. The 257 trapped-rodents belonged to 12 species. Five species of Genus Rattus accounted for 93% of the total capture, of which Rattus exulans and Rattus norvegicus were the two major species caught. All flea specimens, removed from trapped rodents, were identified as Xenopsylla cheopis. The PCR technique was performed on ectoparasite specimens to detect the presence of murine typhus pathogen (Rickettsia typhi) and scrub typhus pathogen (Orientia tsutsugamushi). Thirteen flea specimens (2.6 %) were found to be positive for R. typhi but none for O. tsutsugamushi. An ELISA technique was used to detect the rodent's antibodies against R. typhi and O. tsutsugamushi. Sixty-one rodent serum samples (23.7%) were positive for R. typhi specific IgM, IgG, or both, while 47 of the samples (18.3%) were positive for O. tsutsugamushi. Twenty serum samples from R. norvegicus (7.8%) had detectable antibodies against both R. typhi and O. tsutsugamushi. Our findings revealed the existence of the dual infection of rickettsial pathogens in the same natural hosts. PMID:24820571

Chareonviriyaphap, Theeraphap; Leepitakrat, Warinpassorn; Lerdthusnee, Kriangkrai; Chao, Chien Chung; Ching, Wei Mei

2014-06-01

305

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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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 ect...

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

2011-01-01

306

Relationship of tumor necrosis factor alpha, the nitric oxide synthase pathway, and lipopolysaccharide to the killing of gamma interferon-treated macrophage-like RAW264.7 cells by Rickettsia prowazekii.  

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Macrophage-like RAW264.7 cells are killed by the combination of gamma interferon (IFN-gamma) treatment and infection with Rickettsia prowazekii. The roles of tumor necrosis factor alpha (TNF-alpha), the nitric oxide synthase pathway, and lipopolysaccharide (LPS) in this killing were investigated. R. prowazekii, both the Breinl and Madrid E strains, induced RAW264.7 cells to produce TNF-alpha. However, dead rickettsiae (which cannot kill the IFN-gamma-treated RAW264.7 cells) induced the produc...

Turco, J.; Winkler, H. H.

1994-01-01

307

Effect of mouse lymphokines and cloned mouse interferon-gamma on the interaction of Rickettsia prowazekii with mouse macrophage-like RAW264.7 cells.  

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We studied the effects of crude mouse lymphokines and cloned mouse interferon-gamma on the interaction of Rickettsia prowazekii with mouse macrophage-like RAW264.7 cells. Treatment of RAW264.7 cells with lymphokines before infection, after infection, or both before and after infection with R. prowazekii led to killing of a substantial proportion of the RAW264.7 cells. Such cytotoxicity required both lymphokines and viable R. prowazekii and did not occur in mouse fibroblastic L929 cells. Untre...

Turco, J.; Winkler, H. H.

1984-01-01

308

Conserved Response Regulator CtrA and IHF Binding Sites in the ?-Proteobacteria Caulobacter crescentus and Rickettsia prowazekii Chromosomal Replication Origins  

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CzcR is the Rickettsia prowazekii homolog of the Caulobacter crescentus global response regulator CtrA. CzcR expression partially compensates for developmental defects in ctrA mutant C. crescentus cells, and CzcR binds to all five CtrA binding sites in the C. crescentus replication origin. Conversely, CtrA binds to five similar sites in the putative R. prowazekii replication origin (oriRp). Also, Escherichia coli IHF protein binds over a central CtrA binding site in oriRp. Therefore, CtrA and...

Brassinga, Ann Karen C.; Siam, Rania; Mcsween, William; Winkler, Herbert; Wood, David; Marczynski, Gregory T.

2002-01-01

309

Detection of Rickettsia typhi and seasonal prevalence of fleas collected from small mammals in the Republic of Korea.  

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Fleas were collected from live-captured small mammals to identify potential flea-borne pathogens, seasonal prevalence of flea species, and host preference as part of the US military rodent-borne diseases surveillance program conducted at one US military installation and 10 military training sites, northern Gyeonggi Province, Republic of Korea. During 2003-04, 948 fleas (563 females and 385 males) were recovered from 2,742 small mammals (seven rodent and one insectivore species). Apodemus agrarius (striped field mouse) accounted for 88.9% (2,439/2,742) of the small mammals, followed by Crocidura lasiura (4.2%), Mus musculus (2.9%), Microtus fortis (2.2%), Myodes regulus (0.6%), Micromys minutus (0.5%), Tscherskia triton (0.5%), and Rattus norvegicus (0.3%). Small mammal infestation rates (number with fleas/number captured) ranged from 7.7% (M. minutus and T. triton) to 31.3% (M. regulus). Flea indices were highest for M. regulus (0.69/captured rodent), followed by C. lasiura (0.54), M. fortis (0.41), A. agrarius (0.34), and R. norvegicus (0.33). Overall, Ctenophthalmus congeneroides (51.3%) was more frequently collected, followed by Stenoponia sidimi (42.6%), Rhadinopsylla insolita (5.5%), Neopsylla bidentatiformis (0.4%), Rhadinopsylla concava (0.1%), and Doratopsylla coreana (0.1%). Ctenophthalmus congeneroides was more frequently collected from small mammals during the spring and summer, while S. sidimi was more frequently collected during the winter season. Rickettsia typhi, the causative agent of murine typhus, was detected in 3.2% of specimens (7/220 pools from 654 fleas; minimum field infection rate [number of positive pools/total number of fleas] was 1.1%). PMID:20090029

Kim, Heung-Chul; Yang, Young-Cheol; Chong, Sung-Tae; Ko, Sung-Jin; Lee, Sang-Eun; Klein, Terry A; Chae, Joon-Seok

2010-01-01

310

Human Spotted Fever Group Rickettsioses Are Underappreciated in Southern Taiwan, Particularly for the Species Closely-Related to Rickettsia felis  

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Background Despite increased identification of spotted fever group rickettsioses (SFGR) in animals and arthropods, human SFGR are poorly characterized in Taiwan. Methods Patients with suspected Q fever, scrub typhus, murine typhus, leptospirosis, and dengue fever from April 2004 to December 2009 were retrospectively investigated for SFGR antibodies (Abs). Sera were screened for Rickettsia rickettsii Abs by indirect immunofluorescence antibody assay (IFA), and those with positive results were further examined for Abs against R. rickettsii, R. typhi, R. felis, R. conorii, and R. japonica using micro-immunofluorescence (MIF) tests. Polymerase chain reaction (PCR) for detection of SFGR DNA was applied in those indicated acute infections. Case geographic distribution was made by the geographic information system software. Results A total of 413 cases with paired serum, including 90 cases of Q fever, 47 cases of scrub typhus, 12 cases of murine typhus, 6 cases of leptospirosis, 3 cases of dengue fever, and 255 cases of unknown febrile diseases were investigated. Using IFA tests, a total of 49 cases with 47 (11.4%) and 4 (1.0%) cases had sera potentially positive for R. rickettsii IgG and IgM, respectively. In the 49 cases screened from IFA, MIF tests revealed that there were 5 cases of acute infections (3 possible R. felis and 2 undetermined SFGR) and 13 cases of past infections (3 possible R. felis and 10 undetermined SFGR). None of the 5 cases of acute infection had detectable SFGR DNA in the blood specimen by PCR. Possible acute infection of R. felis was identified in both one case of Q fever and scrub typhus. The geographic distribution of SFGR cases is similar with that of scrub typhus. Conclusions Human SFGR exist and are neglected diseases in southern Taiwan, particularly for the species closely-related to R. felis. PMID:24755560

Lai, Chung-Hsu; Chang, Lin-Li; Lin, Jiun-Nong; Tsai, Kun-Hsien; Hung, Ya-Chien; Kuo, Li-Li; Lin, Hsi-Hsun; Chen, Yen-Hsu

2014-01-01

311

Infectivity, transmission and 16S rRNA sequencing of a rickettsia, Coxiella cheraxi sp. nov., from the freshwater crayfish Cherax quadricarinatus.  

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A rickettsia-like organism isolated from infected, farm-reared Cherax quadricarinatus was cultured in the yolk sac of developing chicken eggs, but could not be cultured in 3 continuous cell lines, bluegill fry (BF-2), fathead minnow (FHM), and Spodoptera frugiperda (Sf-9). The organism was confirmed by fulfilling Koch's postulates as the aetiological agent of mortalities amongst C. quadricarinatus. When C. quadricarinatus was inoculated with the organism, mortality was 100% at 28 degrees C and 80% at an ambient temperature of 24 degrees C. Horizontal transmission with food and via the waterborne route was demonstrated, but mortalities were lower at 30 and 10% respectively over a 4 wk period. The 16S rRNA sequence of 1325 base pairs of the Gram-negative, obligate intracellular organism was 95.6% homologous to Coxiella burnetii. Of 18 species compared to this rickettsia, the next most closely related bacterium was Legionella pneumophila at 86.7%. The suggested classification of this organism is Order Rickettsiales, family Rickettsiaceae, tribe Rickettsieae, within the genus Coxiella. We suggest it should be named Coxiella cheraxi sp. nov. PMID:10918979

Tan, C K; Owens, L

2000-06-19

312

Tratamiento adyuvante con quimioterapia y radioterapia luego de gastrectomía y disección ganglionar D2 en pacientes con cáncer gástrico en el Instituto Nacional de Enfermedades Neoplásicas, Lima, Perú / Adjuvant chemo radiotherapy after gastrectomy and D2 lymphadenectomy in patients with gastric cancer in the National Institute of Cancer, Lima, Peru  

Scientific Electronic Library Online (English)

Full Text Available SciELO Peru | Language: Spanish Abstract in spanish Introducción: La quimio radioterapia adyuvante es una alternativa de tratamiento especialmente para pacientes con cirugías inferiores a D2. El estudio INT016 estableció la quimio radioterapia adyuvante como el cuidado estándar para adenocarcinoma resecado de alto riesgo del estómago en Estados Unido [...] s, sin embargo, se vio obstaculizado por la cirugía sub óptima. Existe controversia acerca de la eficacia de esta terapia adyuvante en pacientes sometidos a linfandenectomía D2. En nuestra institución la linfandenectomía D2 es la cirugía estándar para cáncer gástrico. Objetivo: Demostrar que la terapia adyuvante de quimio y radioterapia en pacientes con cáncer gástrico sometidos a gastrectomía y disección ganglionar D2 es efectiva. Materiales y métodos: Estudio retrospectivo de pacientes con adenocarcinoma gástrico estadío II a IV M0 quienes se sometieron a resección curativa en el Instituto Nacional de Enfermedades Neoplásicas, Lima-Perú en el periodo 2001 a 2006. El tratamiento estándar en la Institución es la linfandenectomía D2 y quimio radioterapia adyuvante de acuerdo al INT016. Las curvas de sobrevida fueron estimadas con el método Kaplan-Meier y comparadas con la prueba logrank. Resultados: 84 pacientes fueron incluidos 60,7% hombres y 39,3% mujeres. La edad media fue 49,5 años. Los estadios patológicos fueron T1-T2 (15,5%), T3-T4 (84,5%), N0-N1 (10,7%), N2-N3 (89,3%). Linfandenectomía D2 fue desarrollada en todos los pacientes. Encontramos una sobrevida libre de enfermedad a 3 años de 17% y una sobrevida global de 23,9%. Cuando se analiza por subgrupos, la sobrevida global en los grupos N1, N2 y N3 fueron 66,7%, 58,9% y 18,3%, respectivamente y la sobrevida libre de enfermedad fue 100%, 51,9% y 16,3%, respectivamente. Conclusiones: La quimio radioterapia adyuvante podría ser una alternativa para disminuir el riesgo de muerte y recaída a tres años principalmente en pacientes con ganglios positivos N1-N2, quienes se sometieron a resección curativa con linfandenectomía D2, pero la recurrencia fue más frecuente en ganglios positivos N3, la quimioterapia en este grupo de pacientes podría ser una alternativa para disminuir la tasa de recaída. Abstract in english Introduction: Adjuvant chemo radiotherapy is the standard treatment in Western countries in gastric cancer patients submitted to curative resection. INT0116 pivotal trial established adjuvant chemo radiation as the standard care for resected high risk adenocarcinoma of the stomach in US however was [...] hampered by suboptimal surgery. There is controversial data about efficacy of this adjuvant therapy in patients who have undergone D2 lymphadenectomy predominantly. In our hospital D2 lymphadenectomy is standard surgery for gastric cancer. Objective: To prove that chemo and radio therapy post gastrectomy and D2 linphadenectomy in patients’ with gastric cancer is effective. Material and methods: Retrospective study with gastric adenocarcinoma patients stage II to IV M0 who underwent curative resection at INEN (Instituto Nacional de Enfermedades Neoplasicas) Lima-Peru between 2001 and 2006. Standard treatment at institution is D2 lymphadenectomy. Chemo radiotherapy according to INT0116 was given like adjuvant therapy. Survival curves were calculated according to Kaplan-Meier method and compared with log-rank test. Results: 84 patients were included 60.7% male and 39.3% female. Mean age was 49.5 years old. The pathologic stages were T1-T2 (15.5%), T3-T4 (84.5%), N0-N1 (10.7%), N2-N3 (89.3%). D2 lymphadenectomy was performed in all patients. The 3-year DFS was 17% and 3-year overall survival was 23.9%. However when we analyzed by subgroups the overall survival, was in group N1 (66.7%) and in group N2 (58.9%) and N3 (18.3%) and 3 years DFS by subgroups were N1 (100%), N2 (51.9%) and N3 (16.3%). Conclusions: Adjuvant chemo radiotherapy decreased risk of death and relapse to three years mainly in patients with node positive N1-N2, who underwent curative

Paola, Montenegro; Lourdes, Flores; Shirley, Quintana; Luís, Casanova; Eloy, Ruíz; Jorge, León; Raúl, Mantilla.

2013-01-01

313

Tratamiento adyuvante con quimioterapia y radioterapia luego de gastrectomía y disección ganglionar D2 en pacientes con cáncer gástrico en el Instituto Nacional de Enfermedades Neoplásicas, Lima, Perú / Adjuvant chemo radiotherapy after gastrectomy and D2 lymphadenectomy in patients with gastric cancer in the National Institute of Cancer, Lima, Peru  

Scientific Electronic Library Online (English)

Full Text Available SciELO Peru | Language: Spanish Abstract in spanish Introducción: La quimio radioterapia adyuvante es una alternativa de tratamiento especialmente para pacientes con cirugías inferiores a D2. El estudio INT016 estableció la quimio radioterapia adyuvante como el cuidado estándar para adenocarcinoma resecado de alto riesgo del estómago en Estados Unido [...] s, sin embargo, se vio obstaculizado por la cirugía sub óptima. Existe controversia acerca de la eficacia de esta terapia adyuvante en pacientes sometidos a linfandenectomía D2. En nuestra institución la linfandenectomía D2 es la cirugía estándar para cáncer gástrico. Objetivo: Demostrar que la terapia adyuvante de quimio y radioterapia en pacientes con cáncer gástrico sometidos a gastrectomía y disección ganglionar D2 es efectiva. Materiales y métodos: Estudio retrospectivo de pacientes con adenocarcinoma gástrico estadío II a IV M0 quienes se sometieron a resección curativa en el Instituto Nacional de Enfermedades Neoplásicas, Lima-Perú en el periodo 2001 a 2006. El tratamiento estándar en la Institución es la linfandenectomía D2 y quimio radioterapia adyuvante de acuerdo al INT016. Las curvas de sobrevida fueron estimadas con el método Kaplan-Meier y comparadas con la prueba logrank. Resultados: 84 pacientes fueron incluidos 60,7% hombres y 39,3% mujeres. La edad media fue 49,5 años. Los estadios patológicos fueron T1-T2 (15,5%), T3-T4 (84,5%), N0-N1 (10,7%), N2-N3 (89,3%). Linfandenectomía D2 fue desarrollada en todos los pacientes. Encontramos una sobrevida libre de enfermedad a 3 años de 17% y una sobrevida global de 23,9%. Cuando se analiza por subgrupos, la sobrevida global en los grupos N1, N2 y N3 fueron 66,7%, 58,9% y 18,3%, respectivamente y la sobrevida libre de enfermedad fue 100%, 51,9% y 16,3%, respectivamente. Conclusiones: La quimio radioterapia adyuvante podría ser una alternativa para disminuir el riesgo de muerte y recaída a tres años principalmente en pacientes con ganglios positivos N1-N2, quienes se sometieron a resección curativa con linfandenectomía D2, pero la recurrencia fue más frecuente en ganglios positivos N3, la quimioterapia en este grupo de pacientes podría ser una alternativa para disminuir la tasa de recaída. Abstract in english Introduction: Adjuvant chemo radiotherapy is the standard treatment in Western countries in gastric cancer patients submitted to curative resection. INT0116 pivotal trial established adjuvant chemo radiation as the standard care for resected high risk adenocarcinoma of the stomach in US however was [...] hampered by suboptimal surgery. There is controversial data about efficacy of this adjuvant therapy in patients who have undergone D2 lymphadenectomy predominantly. In our hospital D2 lymphadenectomy is standard surgery for gastric cancer. Objective: To prove that chemo and radio therapy post gastrectomy and D2 linphadenectomy in patients’ with gastric cancer is effective. Material and methods: Retrospective study with gastric adenocarcinoma patients stage II to IV M0 who underwent curative resection at INEN (Instituto Nacional de Enfermedades Neoplasicas) Lima-Peru between 2001 and 2006. Standard treatment at institution is D2 lymphadenectomy. Chemo radiotherapy according to INT0116 was given like adjuvant therapy. Survival curves were calculated according to Kaplan-Meier method and compared with log-rank test. Results: 84 patients were included 60.7% male and 39.3% female. Mean age was 49.5 years old. The pathologic stages were T1-T2 (15.5%), T3-T4 (84.5%), N0-N1 (10.7%), N2-N3 (89.3%). D2 lymphadenectomy was performed in all patients. The 3-year DFS was 17% and 3-year overall survival was 23.9%. However when we analyzed by subgroups the overall survival, was in group N1 (66.7%) and in group N2 (58.9%) and N3 (18.3%) and 3 years DFS by subgroups were N1 (100%), N2 (51.9%) and N3 (16.3%). Conclusions: Adjuvant chemo radiotherapy decreased risk of death and relapse to three years mainly in patients with node positive N1-N2, who underwent curative

Paola, Montenegro; Lourdes, Flores; Shirley, Quintana; Luís, Casanova; Eloy, Ruíz; Jorge, León; Raúl, Mantilla.

314

Spotted fever from Rickettsia typhi in an older woman: a case report from a geographic area where it would not be expected.  

Science.gov (United States)

We describe the case of a 75-year-old woman presenting with spotted fever followed by acute renal failure and septic shock. The infection was caused by Rickettsia typhi, not reported in Calabria district (southern Italy) since World War II. The diagnosis of murine typhus was made 3 days after admission and was based solely on clinical criteria when her worsening condition required a prompt move to the intensive care unit. Therapy with tigecycline was then started immediately and the patient improved dramatically. The diagnosis of murine typhus was confirmed 10 days after admission by immunofluorescence assay. Our case is an example of how the diagnosis of murine typhus is challenging. However, in the case of a disease lacking specific symptoms, clinicians should never forget that, even in geographic areas considered free of flea-borne diseases, the components of the enzootic cycle are present and the diagnosis should never be underestimated. PMID:25111740

Luciani, Filippo; Cione, Erika; Corsonello, Andrea; Guido, Francesca; De Santis, Salvatore; Cannataro, Roberto; Perri, Mariarita; Caroleo, Maria Cristina; Cannataro, Anna Maria

2014-10-01

315

Exposure and Risk Factors to Coxiella burnetii, Spotted Fever Group and Typhus Group Rickettsiae, and Bartonella henselae among Volunteer Blood Donors in Namibia  

Science.gov (United States)

Background The role of pathogen-mediated febrile illness in sub-Saharan Africa is receiving more attention, especially in Southern Africa where four countries (including Namibia) are actively working to eliminate malaria. With a high concentration of livestock and high rates of companion animal ownership, the influence of zoonotic bacterial diseases as causes of febrile illness in Namibia remains unknown. Methodology/Principal Findings The aim of the study was to evaluate exposure to Coxiella burnetii, spotted fever and typhus group rickettsiae, and Bartonella henselae using IFA and ELISA (IgG) in serum collected from 319 volunteer blood donors identified by the Blood Transfusion Service of Namibia (NAMBTS). Serum samples were linked to a basic questionnaire to identify possible risk factors. The majority of the participants (64.8%) had extensive exposure to rural areas or farms. Results indicated a C. burnetii prevalence of 26.1% (screening titre 1?16), and prevalence rates of 11.9% and 14.9% (screening titre 1?100) for spotted fever group and typhus group rickettsiae, respectively. There was a significant spatial association between C. burnetii exposure and place of residence in southern Namibia (P0.012), especially cattle (P>0.006), were also significantly associated with C. burnetii exposure. Males were significantly more likely than females to have been exposed to spotted fever (Ppathogen never reported in Namibia. Conclusions/Significance These results indicate that Namibians are exposed to pathogenic fever-causing bacteria, most of which have flea or tick vectors/reservoirs. The epidemiology of febrile illnesses in Namibia needs further evaluation in order to develop comprehensive local diagnostic and treatment algorithms. PMID:25259959

Noden, Bruce H.; Tshavuka, Filippus I.; van der Colf, Berta E.; Chipare, Israel; Wilkinson, Rob

2014-01-01

316

Avaliação do protocolo PCR4 de Marchetti em tecidos parafinizados para o diagnóstico da tuberculose cutânea e ganglionar / Evaluation of Marchetti PCR4 amplification assay to the diagnosis of cutaneous and lymph node tuberculosis from formalin-fixed paraffin-embedded tissue  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese INTRODUÇÃO: A tuberculose cutaneoganglionar (TbCG) corresponde a 25,4% dos casos de tuberculose (Tb) extrapulmonar no estado do Amazonas. Os métodos tradicionais, bacteriológicos e histopatológicos envolvem algumas dificuldades diagnósticas, e a reação em cadeia da polimerase (PCR) surge como método [...] alternativo, podendo propiciar resultados específicos e em menor tempo. Nesse sentido, verificou-se a acurácia do protocolo PCR4 de Marchetti et al. no diagnóstico da TbCG comparativamente aos métodos bacteriológicos e histopatológicos. MATERIAIS E MÉTODOS: Realizou-se o nested-PCR com oligonucleotídeos para a IS6110 do complexo do M. tuberculosis em 83 amostras parafinizadas, sendo 52 cutâneas e 31 ganglionares, de pacientes clinicamente suspeitos de TbCG. Todos os casos foram avaliados pelos métodos bacteriológicos e histopatológicos. Foi realizada análise da acurácia entre os resultados obtidos na PCR em relação ao cultivo e à histopatologia. RESULTADOS E DISCUSSÃO: A positividade da PCR em todos os casos estudados foi de 50,6% (42/83), sendo de 59,6% (31/52) em amostras cutâneas e de 35,5% (11/31) nas ganglionares. Em ambos os grupos foram observados resultados falso-positivos e falso-negativos. Algumas hipóteses que podem justificar estes resultados estão relacionadas à presença da IS6110 em micobactérias ambientais da região amazônica e à não-padronização da amostra de DNA amplificado. CONCLUSÃO: O protocolo em avaliação apresentou positividade em percentual semelhante a diferentes protocolos existentes na literatura. Sugere-se o uso da PCR em tecidos parafinizados associada com o cultivo ou com a histopatologia para o diagnóstico definitivo de Tb ganglionar. Para as lesões cutâneas continua sendo necessária a busca de protocolo que amplie a acurácia do método. Abstract in english BACKGROUND: Cutaneous lymph node tuberculosis (CLTb) represents 25.4% of all cases of extra-pulmonary Tb in the state of Amazonas. The current methods of diagnose including bacteriological and histopathological assays involve some technical difficulties, and the polymerase chain reaction - PCR arise [...] as an alternative method allowing specific results faster than the others. In this context the accuracy of PCR4 Marchetti et al. protocol was compared with traditional methods. MATERIAL AND METHOD: Nested-PCR for IS6110 (123 pb) were applied on 83 CLTb suspicious formalin fixed and paraffin embedded samples of tissues (52 cutaneous and 31 lymph node), obtained from 1997 to 2002. All cases were evaluated by bacteriological and histopathological methods. Accuracy analyses were carried out between the PCR amplification results and those related on bacteriological and histopathological methods. RESULTS AND DISCUSSIONS: Positive results of PCR4 were about 50.6% (59.6% in cutaneous samples and of 35.5% in lymph nodes samples). In both groups were observed false-negative and false-positive results. Some hypotheses that explain those results are related to the presence of IS6110 in environmental mycobacterias in the Amazon region and the absence of standardized DNA concentration to amplification assays. CONCLUSIONS: The proposed protocol was as positive as others ones available in the literature. Definitive Tb diagnostic can be obtained on lymph node paraffin embedded PCR in association with bacteriological or histopathological method. A better accuracy of an amplification assay applied to cutaneous Tb suspicious lesions has to be still under research.

Luciana Botinelly Mendonça, Fujimoto; Júlia Ignez, Salem; Maurício Morishi, Ogusku; Luiz Carlos de Lima, Ferreira.

317

Avaliação do protocolo PCR4 de Marchetti em tecidos parafinizados para o diagnóstico da tuberculose cutânea e ganglionar Evaluation of Marchetti PCR4 amplification assay to the diagnosis of cutaneous and lymph node tuberculosis from formalin-fixed paraffin-embedded tissue  

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Full Text Available INTRODUÇÃO: A tuberculose cutaneoganglionar (TbCG corresponde a 25,4% dos casos de tuberculose (Tb extrapulmonar no estado do Amazonas. Os métodos tradicionais, bacteriológicos e histopatológicos envolvem algumas dificuldades diagnósticas, e a reação em cadeia da polimerase (PCR surge como método alternativo, podendo propiciar resultados específicos e em menor tempo. Nesse sentido, verificou-se a acurácia do protocolo PCR4 de Marchetti et al. no diagnóstico da TbCG comparativamente aos métodos bacteriológicos e histopatológicos. MATERIAIS E MÉTODOS: Realizou-se o nested-PCR com oligonucleotídeos para a IS6110 do complexo do M. tuberculosis em 83 amostras parafinizadas, sendo 52 cutâneas e 31 ganglionares, de pacientes clinicamente suspeitos de TbCG. Todos os casos foram avaliados pelos métodos bacteriológicos e histopatológicos. Foi realizada análise da acurácia entre os resultados obtidos na PCR em relação ao cultivo e à histopatologia. RESULTADOS E DISCUSSÃO: A positividade da PCR em todos os casos estudados foi de 50,6% (42/83, sendo de 59,6% (31/52 em amostras cutâneas e de 35,5% (11/31 nas ganglionares. Em ambos os grupos foram observados resultados falso-positivos e falso-negativos. Algumas hipóteses que podem justificar estes resultados estão relacionadas à presença da IS6110 em micobactérias ambientais da região amazônica e à não-padronização da amostra de DNA amplificado. CONCLUSÃO: O protocolo em avaliação apresentou positividade em percentual semelhante a diferentes protocolos existentes na literatura. Sugere-se o uso da PCR em tecidos parafinizados associada com o cultivo ou com a histopatologia para o diagnóstico definitivo de Tb ganglionar. Para as lesões cutâneas continua sendo necessária a busca de protocolo que amplie a acurácia do método.BACKGROUND: Cutaneous lymph node tuberculosis (CLTb represents 25.4% of all cases of extra-pulmonary Tb in the state of Amazonas. The current methods of diagnose including bacteriological and histopathological assays involve some technical difficulties, and the polymerase chain reaction - PCR arise as an alternative method allowing specific results faster than the others. In this context the accuracy of PCR4 Marchetti et al. protocol was compared with traditional methods. MATERIAL AND METHOD: Nested-PCR for IS6110 (123 pb were applied on 83 CLTb suspicious formalin fixed and paraffin embedded samples of tissues (52 cutaneous and 31 lymph node, obtained from 1997 to 2002. All cases were evaluated by bacteriological and histopathological methods. Accuracy analyses were carried out between the PCR amplification results and those related on bacteriological and histopathological methods. RESULTS AND DISCUSSIONS: Positive results of PCR4 were about 50.6% (59.6% in cutaneous samples and of 35.5% in lymph nodes samples. In both groups were observed false-negative and false-positive results. Some hypotheses that explain those results are related to the presence of IS6110 in environmental mycobacterias in the Amazon region and the absence of standardized DNA concentration to amplification assays. CONCLUSIONS: The proposed protocol was as positive as others ones available in the literature. Definitive Tb diagnostic can be obtained on lymph node paraffin embedded PCR in association with bacteriological or histopathological method. A better accuracy of an amplification assay applied to cutaneous Tb suspicious lesions has to be still under research.

Luciana Botinelly Mendonça Fujimoto

2007-06-01

318

Rickettsiosis transmitidas por garrapatas en las Américas: avances clínicos y epidemiológicos, y retos en el diagnóstico / Tick-borne rickettsioses in the Americas: clinical and epidemiological advances, and diagnostic challenges  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Las rickettsiosis son entidades clínicas de tipo zoonótico, causadas por bacterias intracelulares estrictas de los géneros Rickettsia y Orientia, pertenecientes a la familia Rickettsiaceae. Su ecología está determinada por factores ambientales y la presencia de vectores específicos que condicionan e [...] l establecimiento y la epidemiología en diferentes regiones del mundo. En las Américas, durante el siglo XX, únicamente eran reconocidas tres de estas enfermedades: la fiebre manchada de las Montañas Rocosas, el tifus epidémico y el tifus endémico, Sin embargo, a partir del año 2000 se han descrito mas de 10 especies diferentes previamente desconocidas en este continente, tanto en artrópodos como en casos clínicos, hecho que permite clasificarlas como entidades clínicas emergentes y reemergentes. Dadas las manifestaciones clínicas de las enfermedades causadas por rickettsias, siendo la gran mayoría inespecíficas y, por lo mismo, compartidas con otras enfermedades infecciosas, especialmente virales y bacterianas, han sido enmarcadas entre los diagnósticos diferenciales del síndrome febril agudo, tanto en áreas urbanas como tropicales. En la actualidad, se cuenta con métodos diagnósticos directos e indirectos, que son útiles en la identificación del agente infeccioso, en este caso, causante de rickettsiosis. Abstract in english Rickettsioses are a group of zoonotic diseases caused by strict intracellular bacteria of the genus Rickettsia and Orientia which belong to the Rickettsiaceae family. Their ecology is influenced by environmental factors and the presence of specific vectors that determine the establishment and epidem [...] iology in different world regions. In America, during the 20 th century, only three of these diseases were recognized: Rocky Mountain spotted fever, epidemic typhus and endemic typhus. However, since 2000, more than 10 different species that had previously been unknown in this continent have been described, both in arthropods and in clinical cases, fact that classifies them as emerging and re-emerging diseases. Given the clinical manifestations of the diseases caused by rickettsias, being the majority unspecific and, therefore, shared with other infectious diseases, especially viral and bacterial, they have been framed within the differential diagnoses of acute febrile syndrome in urban and tropical areas. Nowadays, there are direct and indirect diagnostic methods, which are useful in the definition of the infectious agent, in this case, the cause of rickettsioses.

Marylin, Hidalgo; Álvaro A, Faccini-Martínez; Gustavo, Valbuena.

2013-09-01

319

Rickettsiosis transmitidas por garrapatas en las Américas: avances clínicos y epidemiológicos, y retos en el diagnóstico / Tick-borne rickettsioses in the Americas: clinical and epidemiological advances, and diagnostic challenges  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Las rickettsiosis son entidades clínicas de tipo zoonótico, causadas por bacterias intracelulares estrictas de los géneros Rickettsia y Orientia, pertenecientes a la familia Rickettsiaceae. Su ecología está determinada por factores ambientales y la presencia de vectores específicos que condicionan e [...] l establecimiento y la epidemiología en diferentes regiones del mundo. En las Américas, durante el siglo XX, únicamente eran reconocidas tres de estas enfermedades: la fiebre manchada de las Montañas Rocosas, el tifus epidémico y el tifus endémico, Sin embargo, a partir del año 2000 se han descrito mas de 10 especies diferentes previamente desconocidas en este continente, tanto en artrópodos como en casos clínicos, hecho que permite clasificarlas como entidades clínicas emergentes y reemergentes. Dadas las manifestaciones clínicas de las enfermedades causadas por rickettsias, siendo la gran mayoría inespecíficas y, por lo mismo, compartidas con otras enfermedades infecciosas, especialmente virales y bacterianas, han sido enmarcadas entre los diagnósticos diferenciales del síndrome febril agudo, tanto en áreas urbanas como tropicales. En la actualidad, se cuenta con métodos diagnósticos directos e indirectos, que son útiles en la identificación del agente infeccioso, en este caso, causante de rickettsiosis. Abstract in english Rickettsioses are a group of zoonotic diseases caused by strict intracellular bacteria of the genus Rickettsia and Orientia which belong to the Rickettsiaceae family. Their ecology is influenced by environmental factors and the presence of specific vectors that determine the establishment and epidem [...] iology in different world regions. In America, during the 20 th century, only three of these diseases were recognized: Rocky Mountain spotted fever, epidemic typhus and endemic typhus. However, since 2000, more than 10 different species that had previously been unknown in this continent have been described, both in arthropods and in clinical cases, fact that classifies them as emerging and re-emerging diseases. Given the clinical manifestations of the diseases caused by rickettsias, being the majority unspecific and, therefore, shared with other infectious diseases, especially viral and bacterial, they have been framed within the differential diagnoses of acute febrile syndrome in urban and tropical areas. Nowadays, there are direct and indirect diagnostic methods, which are useful in the definition of the infectious agent, in this case, the cause of rickettsioses.

Marylin, Hidalgo; Álvaro A, Faccini-Martínez; Gustavo, Valbuena.

320

A prospective evaluation of real-time PCR assays for the detection of Orientia tsutsugamushi and Rickettsia spp. for early diagnosis of rickettsial infections during the acute phase of undifferentiated febrile illness.  

Science.gov (United States)

One hundred and eighty febrile patients were analyzed in a prospective evaluation of Orientia tsutsugamushi and Rickettsia spp. real-time polymerase chain reaction (PCR) assays for early diagnosis of rickettsial infections. By paired serology, 3.9% (7 of 180) and 6.1% (11 of 180) of patients were confirmed to have acute scrub or murine typhus, respectively. The PCR assays for the detection of O. tsutsugamushi and Rickettsia spp. had high specificity (99.4% [95% confidence interval (CI): 96.8-100] and 100% [95% CI: 97.8-100], respectively). The PCR results were also compared with immunoglobulin M (IgM) immunofluorescence assay (IFA) on acute sera. For O. tsutsugamushi, PCR sensitivity was twice that of acute specimen IgM IFA (28.6% versus 14.3%; McNemar's P = 0.3). For Rickettsia spp., PCR was four times as sensitive as acute specimen IgM IFA (36.4% versus 9.1%; P = 0.08), although this was not statistically significant. Whole blood and buffy coat, but not serum, were acceptable specimens for these PCRs. Further evaluation of these assays in a larger prospective study is warranted. PMID:23732256

Watthanaworawit, Wanitda; Turner, Paul; Turner, Claudia; Tanganuchitcharnchai, Ampai; Richards, Allen L; Bourzac, Kevin M; Blacksell, Stuart D; Nosten, François

2013-08-01

 
 
 
 
321

Amputación interescapulotorácica por cromomicosis y carcinoma epidermoide / Amputation interscapulothracique pourchr4omomycose et6 carcinome épidermoide / Interscapulothoracic amputation by chromomycosis and epidermoid carcinoma  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Paciente del sexo masculino y blanco de 74 años de edad, con lesión dermatológica hiperpigmentada y verrucosa de más de 25 años de evolución en codo y antebrazo izquierdo; asimismo posee otra de piel en forma de coliflor y cuya evolución es reciente. Ambas presentaron diagnóstico histopatológico de [...] cromomicosis. El tratamiento inicial fue la exéresis con margen oncológico de la lesión en forma de coliflor y la electrofulguración, curetaje del resto de la lesión y tratamiento antimicótico. En un período de 5 meses el enfermo presenta evolución tórpida con toma del estado general y elefantiasis del miembro superior izquierdo hasta región supraclavicular que obliga a realizarle amputación interescapulotorácica por la técnica de Berger para mejorar la calidad de vida. El diagnóstico histopatológico de los paquetes ganglionares resecados mostró metástasis de un carcinoma epidermoide. Abstract in english The case of a 74-year-old white male patient with a hyperpigmented and verrucose dermatological injury of more than 25 years of evolution in his left elbow and forearm is reported. He also has another cauliflower-like skin injury of recent evolution. Both presented histopathological diagnosis of chr [...] omomycosis. The initial treatment was exeresis with oncological margin of the cauliflower-like injury and electrofulguration, curettage of the rest of the injury and antimycotic treatment. In 5 months, the patient had a torpid evolution with taking of the general state and elephantiasis of the upper left extremity to the supraclavicular region that led to the interscapulothoracic amputation by Berger’s technique to improve his quality of life. The histopathological diagnosis of the resected ganglionar packages showed metastasis of an epidermoid carcinoma.

Hiralio, Collazo Álvarez; Eridán, González Velázquez; Andrés G, Pardillo Morales; Stephen Yecc, Collazo Marín.

322

por valores  

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Full Text Available La era actual se caracteriza por una búsqueda de la identidad del hombre, donde el pivote del cambio organizacional es el individuo; cambiar en este entorno depende, en gran medida, de los valores que imperen en la cultura de la organización. Este trabajo documental intenta identificar aquellos valores, condición sine-qua-non, para el logro de los objetivos de cambio y analizarlos a fin de determinar sus indicadores, con el objeto de presentar una herramienta a las organizaciones que les facilite adaptarse a los nuevos tiempos. Se encontró que los valores: Delegación, Comunicación, Colaboración, Participación y Aprendizaje, son esenciales en los cambios integrales de esta era. Se determinaron 20 indicadores de su presencia. Se concluye que con esta información cada ente puede elaborar instrumentos que le permitan saber si los valores requeridos están presentes y en caso contrario tomar decisiones que alineen a la organización alrededor de los valores humanistas planteados, incrementando así las posibilidades de éxito en el proceso de cambio y por ende, las posibilidades de supervivencia en esta nueva época.

Jazm\\u00EDn D\\u00EDaz-Barrios

2005-01-01

323

Primeiro caso de febre maculosa brasileira branda associada à artrite / First report of mild Brazilian spotted fever associated to arthritis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Descrevemos o primeiro caso brasileiro de Riquetsiose branda, agravada por monoartrite em joelho, em adulto jovem picado por carrapato na perna esquerda na região de Camburi, localizada no município de São Sebastião, sul da região costeira do estado de São Paulo, Mata Atlântica, Brasil. O paciente a [...] presentou uma escara de inoculação no local da picada do carrapato, associada ao aumento ganglionar em virilha esquerda, febre, poliartralgia, cefaleia e erupção macular. Vinte dias após o episódio da picada de carrapato, o paciente apresentou monoartrite em joelho direito. O diagnóstico de Riquetsiose branda foi estabelecido pela análise imunológica sequencial em amostras de soro e líquido sinovial, tendo sido empregada a técnica de imunofluorescência (IF) indireta para anticorpos reativos contra Rickettsia parkeri e Rickettsia rickettsii. A Riquetsiose branda é uma zoonose emergente, que deve ser investigada pelos médicos, incluindo reumatologistas, em pacientes que apresentem erupção macular, febre e, eventualmente, artrite, após visita ao sul da região costeira da Mata Atlântica no Brasil. Abstract in english We describe the first Brazilian case of mild Rickettsiosis, complicated by knee monoarthritis, in young adult bitten by a tick on his left leg in Camburi zone, located in São Sebastião municipality, southern coastal region of the State of São Paulo, in the Atlantic rainforest region, Brazil. The pat [...] ient developed inoculation eschar at the tick bite site associated with enlarged lymph nodes in the left groin, fever, polyarthralgia, headache and macular rash. Twenty days after tick bite episode, he displayed monoarthritis in his right knee. The diagnosis of mild Rickettsiosis was established by sequential immunological analysis in serum and synovial fluid, using the indirect immunofluorescence (IF) assay for antibodies reactive with Rickettsia parkeri and Rickettsia rickettsii. The mild Rickettsiosis is an emerging zoonosis, that must be investigated by physicians, including rheumatologists, in patients that present macular rash, fever and eventually arthritis, after visiting the southern coastal Atlantic rainforest region in Brazil.

Virgínia Lucia Nazario, Bonoldi; Roberta Gonçalves, Marangoni; Giancarla, Gauditano; Jonas, Moraes-Filho; Marcelo Bahia, Labruna; Natalino Hajime, Yoshinari.

2014-06-01

324

por láser  

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Full Text Available En el presente trabajo, la técnica Espectroscopia de plasmas producidos por láser (Laser-induced breakdown spectroscopy –LIBS– se aplicó a la determinación cuan- titativa de Na en agua natural dulce, de interés en agricultura para el estudio de la alcalinidad de aguas de regadío. Para efectuar el análisis, se prepararon soluciones con concentraciones conocidas del analito, se mezclaron con óxido de calcio y se compactaron en pastillas sólidas. Los plasmas se produjeron en aire a presión atmos- férica utilizando un láser pulsado Nd:YAG. Se construyó una curva de calibración y se calculó el límite de detección. Se analizaron muestras de agua natural y los resultados se compararon con los obtenidos mediante espectroscopia de absorción atómica. Se demostró la factibilidad del método para la determinación de Na en agua natural dulce.

Mayra Garcimu\\u00F1o

2013-01-01

325

Ultrastructural description of new Rickettsia-like organisms in the commercial abalone Haliotis tuberculata (Gastropoda: Haliotidae) from the NW of Spain.  

Science.gov (United States)

Rickettsia-like organisms (RLOs) were found in the commercially farmed abalone Haliotis tuberculata in the northwestern region of the Atlantic Coast of Spain and are described from light and transmission electron microscopy observations. The RLOs measured approximately 1.6 x 0.9 microm and were found in intracytoplasmic, spherical to ellipsoidal vacuoles (up to 8 microm) in the epithelial cells of the digestive diverticulae. The morphological ultrastructure of these organisms was typically prokaryotic, including a plasmalemma and a thin Gram-negative type cell wall. Several ultrastructural changes were observed in the epithelial cells of the host containing the RLOs. The nuclei became pycnotic and several basophilic dense inclusions appeared in the cytoplasm. In addition, the host cell appeared lysed and was ruptured in advanced stages of infection. It was impossible to ascertain whether the RLOs are responsible for this disease, as a haplosporidian infection was also present. We can only conclude that the presence of RLOs simultaneously with a haplosporidian parasite may contribute to the mortality of the abalone host. PMID:17058604

Azevedo, Carlos; Conchas, Ramón F; Tajdari, Jessica; Montes, Jaime

2006-08-30

326

Analysis of Rickettsia typhi-infected and uninfected cat flea (Ctenocephalides felis) midgut cDNA libraries: deciphering molecular pathways involved in host response to R. typhi infection  

Science.gov (United States)

Murine typhus is a flea-borne febrile illness that is caused by the obligate intracellular bacterium, Rickettsia typhi. The cat flea, Ctenocephalides felis, acquires R. typhi by imbibing a bloodmeal from a rickettsemic vertebrate host. To explore which transcripts are expressed in the midgut in response to challenge with R. typhi, cDNA libraries of R. typhi-infected and uninfected midguts of C. felis were constructed. In this study, we examined midgut transcript levels for select C. felis serine proteases, GTPases and defence response genes, all thought to be involved in the fleas response to feeding or infection. An increase in gene expression was observed for the serine protease inhibitors and vesicular trafficking proteins in response to feeding. In addition, R. typhi infection resulted in an increase in gene expression for the chymotrypsin and rab5 that we studied. Interestingly, R. typhi infection had little effect on expression of any of the defence response genes that we studied. We are unsure as to the physiological significance of these gene expression profiles and are currently investigating their potential roles as it pertains to R. typhi infection. To our knowledge, this is the first report of differential expression of flea transcripts in response to infection with R. typhi. PMID:20017753

Dreher-Lesnick, S. M.; Ceraul, S. M.; Lesnick, S. C.; Gillespie, J. J.; Anderson, J. M.; Jochim, R. C.; Valenzuela, J. G.; Azad, A. F.

2011-01-01

327

Detection of Rickettsia rickettsii in the tick Amblyomma cajennense in a new Brazilian spotted fever-endemic area in the state of Minas Gerais  

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Full Text Available The present study evaluated rickettsial infection in Amblyomma spp. ticks collected in a farm in Coronel Pacheco, a Brazilian spotted fever (BSF endemic area. A total of 78 A. cajennense and 78 A. dubitatum free-living adult ticks were collected and tested by polymerase chain reaction (PCR targeting a fragment of the rickettsial gene gltA. Only one pool of three A. cajennense ticks showed the expected product by PCR. This pool was further tested by PCR using sets of primers targeting the rickettsial genes gltA, ompA, and ompB. All reactions yielded the expected bands that by sequencing, showed 100% identity to the corresponding sequences of the Rickettsia rickettsii gene fragments gltA (1063-bp, ompA (457-bp, and ompB (720-bp. The minimal infection rate of R. rickettii in the A. cajennense population was 1.28% (at least one infected tick within 78 ticks.The present study showed molecular evidence for the presence of R. rickettsii in A. cajennense from a BSF-endemic area in Coronel Pacheco, state of Minas Gerais. Although R. rickettsii has been previously reported infecting A. cajennense ticks in Brazil and other Latin American countries, the present study performed the first molecular characterization of R. rickettsii from the tick A. cajennense.

Elizângela Guedes

2005-12-01

328

Linfadenopatía por silicona en una paciente con prótesis mamarias / Silicone-induced lymphadenopathy in a patient suffering from mammary prosthesis: a case report  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Se presenta el caso de una mujer de 47 años, con adenopatías axilares izquierdas, sin antecedentes médicos y a quien se le habían colocado implantes mamarios 8 años antes con fines estéticos. Se realizó resección ganglionar y la patología reportó células gigantes multinucleadas tipo cuerpo extraño, [...] con abundantes vacuolas citoplasmáticas y linfocitos polimorfonucleares con lo que se estableció el diagnóstico de adenopatía por silicona y se procedió a la remoción y cambio de la prótesis. La biopsia por aspiración con aguja fina (BACAF) de los ganglios linfáticos que drenan el sitio donde se localiza la prótesis puede hacer el diagnóstico de linfadenopatía por silicona y a la vez permite descartar la presencia de un proceso maligno que pudiera coincidir en algunas pacientes. Abstract in english This is a case report of a 47-year old woman having no antecedents of disease, but a surgical history of silicone breast-implants 8 years beforehand. The patient’s complaint concerned the left axillary lymph nodes. A ganglion resection was done and fine needle aspiration biopsy (FNAB) revealed giant [...] multinucleated cells having abundant cytoplasmatic vacuoles and polymorphonuclear lymphocytes leading to a diagnosis of silicon-induced adenopathy. The prosthesis was then removed and changed. Lymph node FNAB is able to diagnose silicone lymphadenopathy and excludes malignant neoplasm.

Germán, García-Soto; Jorge, Castaño; Ronald, Smith-Meneses.

2006-06-01

329

Retrospective clinical and molecular analysis of conditioned laboratory dogs (Canis familiaris) with serologic reactions to Ehrlichia canis, Borrelia burgdorferi, and Rickettsia rickettsii.  

Science.gov (United States)

Dogs are susceptible to different tickborne infections, including members of the Anaplasmataceae (Ehrlichia canis, E. ewingii, E. chaffeensis, Anaplasma phagocytophilum, A. platys), Borrelia burgdorferi, and Rickettsia rickettsii. These diseases can manifest with clinical signs including fever, anorexia, malaise, lameness, rash, and bleeding episodes; however, these signs are nonpathognomonic, and infections can occur in the absence of clinical signs. Hematologic abnormalities can include leukopenia, thrombocytopenia, hyperproteinemia and hypergammaglobulinemia. In biomedical research, diseases such as canine monocytic ehrlichiosis, Lyme disease, and Rocky Mountain spotted fever may cause morbidity among exposed dogs and confound research results. Random-source dogs are susceptible to these diseases because of their increased risk of arthropod exposure. Nonpurpose bred, randomly selected conditioned dogs (n = 21) were examined; blood samples were taken for hematology, biochemistry analysis, tickborne pathogen serology, and PCR. Of these, 2 dogs (10% of the population) presented with illness characterized by fever, malaise, lameness, or hemostatic abnormalities, and 15 (71%) had antibodies to one or more tickborne pathogens. No specific hematologic or biochemical differences were apparent between seronegative dogs and seropositive dogs reactive to all 3 pathogens. E. canis and B. burgdorferi PCR of tissues and blood were negative for all dogs. PCR amplification of several Ehrlichia and Anaplasma genes yielded no positive samples. From this cohort of dogs, serologic and molecular results indicate prior exposure without active infection or clinical disease. Exposure to and potential for infection with these bacteria and other pathogens may contribute to blood and tissue alterations that could confound experiments and lead to misinterpretation of data in canine models. PMID:18947166

Scorpio, Diana G; Wachtman, Lynn M; Tunin, Richard S; Barat, Nicole C; Garyu, Justin W; Dumler, J Stephen

2008-09-01

330

Rickettsia prowazekii uses an sn-glycerol-3-phosphate dehydrogenase and a novel dihydroxyacetone phosphate transport system to supply triose phosphate for phospholipid biosynthesis.  

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Rickettsia prowazekii is an obligate intracellular pathogen that possesses a small genome and a highly refined repertoire of biochemical pathways compared to those of free-living bacteria. Here we describe a novel biochemical pathway that relies on rickettsial transport of host cytosolic dihydroxyacetone phosphate (DHAP) and its subsequent conversion to sn-glycerol-3-phosphate (G3P) for synthesis of phospholipids. This rickettsial pathway compensates for the evolutionary loss of rickettsial glycolysis/gluconeogenesis, the typical endogenous source of G3P. One of the components of this pathway is R. prowazekii open reading frame RP442, which is annotated GpsA, a G3P dehydrogenase (G3PDH). Purified recombinant rickettsial GpsA was shown to specifically catalyze the conversion of DHAP to G3P in vitro. The products of the GpsA assay were monitored spectrophotometrically, and the identity of the reaction product was verified by paper chromatography. In addition, heterologous expression of the R. prowazekii gpsA gene functioned to complement an Escherichia coli gpsA mutant. Furthermore, gpsA mRNA was detected in R. prowazekii purified from hen egg yolk sacs, and G3PDH activity was assayable in R. prowazekii lysed-cell extracts. Together, these data strongly suggested that R. prowazekii encodes and synthesizes a functional GpsA enzyme, yet R. prowazekii is unable to synthesize DHAP as a substrate for the GpsA enzymatic reaction. On the basis of the fact that intracellular organisms often avail themselves of resources in the host cell cytosol via the activity of novel carrier-mediated transport systems, we reasoned that R. prowazekii transports DHAP to supply substrate for GpsA. In support of this hypothesis, we show that purified R. prowazekii transported and incorporated DHAP into phospholipids, thus implicating a role for GpsA in vivo as part of a novel rickettsial G3P acquisition pathway for phospholipid biosynthesis. PMID:20581209

Frohlich, Kyla M; Roberts, Rosemary A W; Housley, Nicole A; Audia, Jonathon P

2010-09-01

331

Loop-mediated isothermal amplification for Rickettsia typhi (the causal agent of murine typhus): problems with diagnosis at the limit of detection.  

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Murine typhus is a flea-borne disease of worldwide distribution caused by Rickettsia typhi. Although treatment with tetracycline antibiotics is effective, treatment is often misguided or delayed due to diagnostic difficulties. As the gold standard immunofluorescence assay is imperfect, we aimed to develop and evaluate a loop-mediated isothermal amplification (LAMP) assay. LAMP assays have the potential to fulfill the WHO ASSURED criteria (affordable, sensitive, specific, user friendly, robust and rapid, equipment free, deliverable to those who need them) for diagnostic methodologies, as they can detect pathogen-derived nucleic acid with low technical expenditure. The LAMP assay was developed using samples of bacterial isolates (n=41), buffy coat specimens from R. typhi PCR-positive Lao patients (n=42), and diverse negative controls (n=47). The method was then evaluated prospectively using consecutive patients with suspected scrub typhus or murine typhus (n=266). The limit of detection was ?40 DNA copies/LAMP reaction, with an analytical sensitivity of <10 DNA copies/reaction based on isolate dilutions. Despite these low cutoffs, the clinical sensitivity was disappointing, with 48% (95% confidence interval [95% CI], 32.5 to 62.7%) (specificity, 100% [95% CI, 100 to 100%]) in the developmental phase and 33% (95% CI, 9.2 to 56.8%) (specificity, 98.5% [95% CI, 97.0% to 100%]) in the prospective study. This low diagnostic accuracy was attributed to low patient R. typhi bacterial loads (median, 210 DNA copies/ml blood; interquartile range, 130 to 500). PCR-positive but LAMP-negative samples demonstrated significantly lower bacterial loads than LAMP-positive samples. Our findings highlight the diagnostic challenges for diseases with low pathogen burdens and emphasize the need to integrate pathogen biology with improved template production for assay development strategies. PMID:24371248

Dittrich, Sabine; Castonguay-Vanier, Josée; Moore, Catrin E; Thongyoo, Narongchai; Newton, Paul N; Paris, Daniel H

2014-03-01

332

Estudio Comparativo de Disección Ganglionar D1 y D2 para el Cáncer Gástrico Avanzado en el Hospital Rebagliati / Comparative Study of D1 and D2 Ganglionic Dissection in Advanced GAstric Cancer at Rebagliati Hospital  

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Full Text Available SciELO Peru | Language: Spanish Abstract in spanish La gastrectomía con linfadenectomía D2 es la cirugía estándar en la mayoría de centros hospitalarios del Perú debido a que la técnica quirúrgica japonesa ha mostrado los mejores resultados en todo el mundo. Sin embargo nunca se ha realizado un estudio comparando los resultados de linfadenectomía D2 [...] con D1 en nuestro país. El presente estudio de tipo cohorte retrospectivo compara la linfadenectomía D2 versus D1 en el tratamiento quirúrgico del cáncer gástrico. 316 pacientes fueron sometidos a cirugía por cáncer gástrico entre Enero del 2000 y Diciembre del 2002 en el Hospital Nacional Rebagliati y se seleccionaron en forma aleatoria un total de 100 pacientes, 50 de ellos fueron sometidos a linfadenectomía D1 y otros 50 a linfadenectomía D2 respectivamente. La mortalidad fue de 8% para D1 y 4 % para D2 (p: NS), mientras que la morbilidad fue de 24% para D1 y 12% para D2 (p: NS). La sobrevida a 3 años fue de 36% para D1 y 56% para D2 estableciendo una diferencia estadísticamente significativa (p: 0.04) Se recomienda la gastrectomía con linfadenectomía D2 como tratamiento quirúrgico de elección para el cáncer gástrico avanzado. Abstract in english Gastrectomy with D2 lymphadenectomy is the standard surgical procedure in most hospitals in Peru due to the fact that this Japanese surgical technique has proven to provide the best results in the world. However, no comparative study of the results of D1 and D2 lymphadenectomies has ever been perfor [...] med in our country. This retrospective cohort study compares D2 lymphadenectomy versus D1 in surgical treatment of gastric cancer. Between January 2000 and December 2002, 316 patients underwent surgery at the Rebagliati National Hospital and a total of 100 patients were randomly selected, 50 of which underwent a D1 lymphadenectomy and 50 a D2 lymphadenectomy. Mortality rates were 8% for D1 lymphadenectomy and 4% for D2, whereas morbidity rates were 24% for D1 and 12% for D2. Survival after 3 years was 36% for D1 and 56% for D2 thus establishing a statistically significant difference (p = 0.04). We recommend gastrectomy with D2 lymphadenectomy as the surgical treatment of choice for advanced gastric cancer.

Consuelo, Cornejo; Michel, Portanova.

333

Pecoma pélvico del ligamento ancho con metástasis ganglionares: presentación de un caso y revisión de la literatura / Pelvic PEcoma of the broad ligament with lymph node metastasis: Case report and bibliographic review  

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Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Objetivos: Describimos y documentamos el primer caso de PEComa publicado en España según la base de datos Pub Med. Y revisamos la bibliografía existente sobre este tipo de tumores. Métodos/Resultados: Se Trata de una paciente de 39 años con un tumor pélvico de 9 cms. descubierto en una revisión gine [...] cológica rutinaria. El TAC muestra múltiples adenopatías periaórticas que se extienden hasta vena renal izquierda El diagnóstico de PEComa se obtiene por punción con aguja gruesa. Se realiza exéresis del tumor junto a anexo izquierdo y linfadenectomía aortoiliaca. El resultado patológico confirma el diagnóstico tras la inmunohistoquímica con actina de músculo liso y HMB-45. No recibió tratamiento adyuvante. Tras un año de seguimiento la paciente no muestra en el TAC signos de recidiva. Se realiza una amplia búsqueda bibliográfica en Pub Med encontrando 73 referencias a este tipo de tumor cuyas conclusiones se exponen en este articulo. Conclusiones: El tumor de celulas epitelioides perivasculares, PEComa, es una neoplasia mesenquimal de muy baja incidencia y con malignidad incierta. Tumores muy raros: el angiomiolipoma epitelioide, la linfangioleiomiomatosis, el linfangiomioma, el tumor miomelanocitico del ligamento falciforme, el tumor pulmonar de celulas claras "de azucar" y su variante extrapulmonar; son antiguas descripciones de lo que ahora es una única entidad tumoral denominada PEComa. Aun no de ha descrito la célula que en tejidos normales da origen a este tumor. Afectando principalmente a mujeres en edad media, pueden encontrarse en cualquier lugar anatómico. Su tratamiento es quirúrgico aunque se desconoce el papel de la linfadenectomía y del tratamiento adyuvantes. Abstract in english Objective: We describe and document the first case of PEcoma published in Spain following the PubMed database. We review the bibliography about these tumors. Methods/Results: 39-year-old female patient with a 9 cm pelvic tumor discovered in a routine gynecologic review. CT scan showed multiple peria [...] ortic adenopathies extending up to the left renal vein. The diagnosis of PEcoma was obtained by needle biopsy. Tumor excision including left annex and aortoiliac lymphadenectomy were performed. Pathology confirmed the diagnosis after immunohistochemical study with smooth muscle actin and HMB-45. No adjuvant treatment was given. After one year of follow-up the patient does not show signs of recurrence of the CT scan. A PubMed search was performed finding 73 references about this kind of tumor the conclusions of which are exposed in this article. Conclusions: Perivascular epithelioid cell tumor, PEcoma, is a very low incidence mesenchymal neoplasia with uncertain malignancy. Very rare tumors such as epithelioid angiomyolipoma, lymphangioleiomyomatosis, lymphangiomyoma, myelomelanocytic tumor of the falciform ligament, "sugar" clear cell lung tumor and its extrapulmonary variant are all descriptions of what is now a unique tumoral entity named PEcoma. It has not been described yet the normal tissue cell giving origin to this tumor. It affects mainly middle age women, and may appear in any anatomical site. Treatment is surgical, although the role of lymphadenectomy and adjuvant treatment is unknown.

Raul, Tobalina Bonis; Tomás, Pérez Domínguez; Fernanda, Relea Calatayud; Enrique, Cazenave Jiménez; M. A., Piris; Nemesio, Jiménez López-Lucendo.

334

Pecoma pélvico del ligamento ancho con metástasis ganglionares: presentación de un caso y revisión de la literatura / Pelvic PEcoma of the broad ligament with lymph node metastasis: Case report and bibliographic review  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Objetivos: Describimos y documentamos el primer caso de PEComa publicado en España según la base de datos Pub Med. Y revisamos la bibliografía existente sobre este tipo de tumores. Métodos/Resultados: Se Trata de una paciente de 39 años con un tumor pélvico de 9 cms. descubierto en una revisión gine [...] cológica rutinaria. El TAC muestra múltiples adenopatías periaórticas que se extienden hasta vena renal izquierda El diagnóstico de PEComa se obtiene por punción con aguja gruesa. Se realiza exéresis del tumor junto a anexo izquierdo y linfadenectomía aortoiliaca. El resultado patológico confirma el diagnóstico tras la inmunohistoquímica con actina de músculo liso y HMB-45. No recibió tratamiento adyuvante. Tras un año de seguimiento la paciente no muestra en el TAC signos de recidiva. Se realiza una amplia búsqueda bibliográfica en Pub Med encontrando 73 referencias a este tipo de tumor cuyas conclusiones se exponen en este articulo. Conclusiones: El tumor de celulas epitelioides perivasculares, PEComa, es una neoplasia mesenquimal de muy baja incidencia y con malignidad incierta. Tumores muy raros: el angiomiolipoma epitelioide, la linfangioleiomiomatosis, el linfangiomioma, el tumor miomelanocitico del ligamento falciforme, el tumor pulmonar de celulas claras "de azucar" y su variante extrapulmonar; son antiguas descripciones de lo que ahora es una única entidad tumoral denominada PEComa. Aun no de ha descrito la célula que en tejidos normales da origen a este tumor. Afectando principalmente a mujeres en edad media, pueden encontrarse en cualquier lugar anatómico. Su tratamiento es quirúrgico aunque se desconoce el papel de la linfadenectomía y del tratamiento adyuvantes. Abstract in english Objective: We describe and document the first case of PEcoma published in Spain following the PubMed database. We review the bibliography about these tumors. Methods/Results: 39-year-old female patient with a 9 cm pelvic tumor discovered in a routine gynecologic review. CT scan showed multiple peria [...] ortic adenopathies extending up to the left renal vein. The diagnosis of PEcoma was obtained by needle biopsy. Tumor excision including left annex and aortoiliac lymphadenectomy were performed. Pathology confirmed the diagnosis after immunohistochemical study with smooth muscle actin and HMB-45. No adjuvant treatment was given. After one year of follow-up the patient does not show signs of recurrence of the CT scan. A PubMed search was performed finding 73 references about this kind of tumor the conclusions of which are exposed in this article. Conclusions: Perivascular epithelioid cell tumor, PEcoma, is a very low incidence mesenchymal neoplasia with uncertain malignancy. Very rare tumors such as epithelioid angiomyolipoma, lymphangioleiomyomatosis, lymphangiomyoma, myelomelanocytic tumor of the falciform ligament, "sugar" clear cell lung tumor and its extrapulmonary variant are all descriptions of what is now a unique tumoral entity named PEcoma. It has not been described yet the normal tissue cell giving origin to this tumor. It affects mainly middle age women, and may appear in any anatomical site. Treatment is surgical, although the role of lymphadenectomy and adjuvant treatment is unknown.

Raul, Tobalina Bonis; Tomás, Pérez Domínguez; Fernanda, Relea Calatayud; Enrique, Cazenave Jiménez; M. A., Piris; Nemesio, Jiménez López-Lucendo.

2008-08-01

335

The Rickettsia prowazekii ExoU homologue possesses phospholipase A1 (PLA1), PLA2, and lyso-PLA2 activities and can function in the absence of any eukaryotic cofactors in vitro.  

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Here we have characterized the Rickettsia prowazekii RP534 protein, a homologue of the Pseudomonas aeruginosa ExoU phospholipase A (PLA) secreted cytotoxin. Our studies showed that purified recombinant RP534 PLA possessed the predicted PLA(2) and lyso-PLA(2) activities based on what has been published for P. aeruginosa ExoU. RP534 also displayed PLA(1) activity under the conditions tested, whereas ExoU did not. In addition, recombinant RP534 displayed a basal PLA activity that could hydrolyze phosphatidylcholine in the absence of any eukaryotic cofactors. Interestingly, the addition of bovine liver superoxide dismutase 1 (SOD1), a known activator of P. aeruginosa ExoU, resulted in an increased rate of RP534-catalyzed phospholipid hydrolysis, indicating that mechanisms of activation of the ExoU family of PLAs may be evolutionarily conserved. The mechanism of SOD1-dependent stimulation of RP534 was further examined using active site mutants and a fluorogenic phospholipid substrate whose hydrolysis by RP534 over a short time course is measureable only in the presence of SOD1. These studies suggest a mechanism by which SOD1 stimulates RP534 activity once it has bound to the substrate. We also show that antibody raised against RP534 was useful for immunoprecipitating active RP534 from R. prowazekii lysed cell extracts, thus verifying that this protein is expressed and active in rickettsiae isolated from embryonated hen egg yolk sacs. PMID:21764940

Housley, Nicole A; Winkler, Herbert H; Audia, Jonathon P

2011-09-01

336

Cuantificación de ADN como factor pronóstico en un caso de Carcinoma de células Acinares de parótida diagnosticado por PAAF / DNA quantification as prognostic factor in a case of Acinar Cell Carcinoma of the parotid gland, diagnosed by FNA  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Presentamos el caso de un varón de 43 años de edad que consulta por una tumoración preauricular derecha dolorosa a la palpación que, según refiere, tiene más de tres años de evolución. Se realiza punción aspiración con aguja fina que informa de compatible con carcinoma de células acinares, por lo qu [...] e se realiza cuantificación de ADN por citometría de imagen. Los parámetros biológicos estudiados (ploidía, fase S, células por encima de 5c) indican que se trata de una lesión de bajo grado de malignidad. Con estos datos se practica parotidectomía total conservadora del facial, sin vaciamiento ganglionar. El paciente se encuentra, un año después, asintomático y libre de signos tumorales residuales. Abstract in english Hereby we present a case of a 43-years-old male who complained of a three years history preauricular painful mass. Fine needle aspiration cytology was performed, diagnosing of compatible with acinar cell carcinoma, thus DNA quantification by image cytometry was carried out. Biological parameters stu [...] died (ploidy, S-phase, 5-c exceeding rate) showed that it is a low grade of malignancy lesion. Total parotidectomy conservative of facial nerve was recommended, without regional lymphadenectomy. Patient remains, one year later, asymptomatic and free of disease.

Javier, Azúa Romeo; Juan Carlos, Sánchez Garnica; Javier, Azúa Blanco; Mayte, Tovar Lázaro.

337

Factores morfológicos asociados al pronóstico de pacientes operados por cáncer gástrico incipiente / Pathological features associated with survival in early gastric cancer  

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Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Introducción: El cáncer gástrico incipiente (CGI) es aquel que compromete la mucosa o submucosa gástrica independientemente del compromiso ganglionar linfático, estimándose su prevalencia en Chile inferior al 20%o. El objetivo de este estudio es determinar prevalencia de CGI y asociación de variable [...] s biode-mográficas y morfológicas con la supervivencia (SV) de pacientes resecados por CGI. Material y Método: Estudio de cohorte retrospectiva. Se estudiaron variables biodemográficas y morfológicas de 106 pacientes resecados por CGI entre 1986-2007. Se aplicó estadística descriptiva y analítica; confección de curvas de SV, y finalmente se aplicaron modelos de regresión logística para realizar ajuste, calcular odds ratio y sus respectivos intervalos de confianza de 95%. Resultados: 15% correspondió a CGI. La mediana de edad fue 63 años y el 60% correspondió a género masculino con una SV global a 5 años de 91%. Se observaron diferencias estadísticas significativas entre tumores mucosos y submucosos en cuanto a la localización tumoral y compromiso linfonodal junto con presentarse el compromiso nodal más frecuentemente en tumores > 35mm poco diferenciados y difusos de Lauren. El análisis multivariado identificó como factores asociados a la SV: tamaño tumoral, grado de diferenciación histológica en su variedad poco diferenciado, tipo difuso de Lauren y compromiso ganglionar linfático. Conclusiones: Se verificó una prevalencia de CGI de 15%, los que resecados presentan SV de 91% a 5 años. El compromiso linfonodal es un factor asociado a la SV; y además, se relaciona con tamaño tumoral, tipo histológico según Lauren, grado de diferenciación histológico y nivel de infiltración. Abstract in english Background: Early gastric cancer corresponds to those tumors that only involve mucosa and submuco-sa. It is associated with a high survival rate. Aim: To determine pathological factors associated with survival in early gastric cancer. Material and Methods: Analysis of pathological records of 106 pat [...] ients, with a median age of 63 years (60%> males), subjected to a gastrectomy for early gastric cancer. Follow up was performed according to data in the clinical records and death certificates obtained at the Chilean National Death Registry. Results: Five years global survival of patients was 91%o. Lymph node involvement was more common among tumors bigger than 35 mm, with a low degree of differentiation and among those tumors classified as diffuse according to Lauren. Survival was significantly lower for bigger tumors, those with of a low degree of differentiation, diffuse tumors according to Lauren and those with lymph node involvement. Conclusions: Early gastric cancer has a high five years survival. Bigger tumors, those with a low degree of differentiation and those with lymph node involvement are associated with lower survival rates.

ÓSCAR, TAPIA E; PATRICIA, GARCÍA M; CARLOS, MANTEROLA D; MIGUEL, VILLASECA H; JUAN CARLOS, ARAYA O; JUAN CARLOS, ROA S.

338

Linfadenitis de causa tuberculosa: diagnóstico por punción aspirativa con aguja fina / Lymphadenitis of tuberculosis etiology: diagnosis by fine needle aspiration biopsy  

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Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Fundamento: la tuberculosis es un problema serio de salud mundial. La propagación de la infección por el VIH agudiza su impacto. La tuberculosis extrapulmonar supone el 10-20 % del total que padecen los enfermos inmunocompetentes. Caso clínico: se presenta un paciente de treinta y dos años de edad, [...] sexo masculino, raza mestiza, procedente del área rural, con antecedentes de ser paciente con VIH/SIDA, que es ingresado en los servicios de atención clínica del hospital Universitario Manuel Ascunce Domenech, por presentar adenopatías latero- cervical derecha e inguinales, de dos meses de evolución, fiebre inicial de 39?C, tos escasa, sin expectoración. Para la confirmación del diagnóstico clínico inicial de posible tuberculosis ganglionar, se indica entre los complementarios, la Punción Aspirativa con Aguja Fina y se realiza cultivo microbiológico de la muestra obtenida. Conclusiones: el presente tema adquiere importancia en la actualidad, en la que el diagnóstico rápido de la enfermedad tuberculosa es una necesidad, evita tratamientos innecesarios, posibilita el cultivo y permite seleccionar qué pacientes requieren biopsias ganglionares y estudio histopatológico para diagnóstico diferencial y definitivo de la enfermedad. Así como constituye una herramienta más de confirmación del diagnóstico clínico de sospecha, a menos costo. Abstract in english Background: tuberculosis (TB) is a serious worldwide health problem. The spread of HIV infection increases its impact. Extrapulmonary tuberculosis accounts for 10-20 % of TB which suffers inmmunocompetent patients. Clinical case: a 32 years old, male patient, Afro-American descendent, coming from a [...] rural area with a history of HIV/AIDS patient is presented. The patient was admitted in the internal medicine service at the Manuel Ascunce Domenech University Hospital, presenting right laterocervical and inguinal adenopathies of two month of evolution, fever of 39oC, intermittent cough without expectoration. To confirm the initial clinical diagnosis of possible ganglial tuberculosis, fine-needle aspiration biopsy was recommended as a complementary examination and microbiological culture of the sample was performed. Conclusions: this patient´s case has developed importance today, in which quick diagnosis of tuberculosis is a necessity, avoiding unnecessary treatments, enables microbiological culture and allows selecting which patients require ganglion biopsies and histopathological study for differential and definitive diagnosis of the disease. As well as, it is one tool for confirmation of clinical diagnosis of suspicion, at lower cost.

Odalys, Durruthy Wilson; Nayvis, Suazo Valle; Daysi, Perón Ortiz.

339

Síndrome de Frey por submaxilectomía y tratamiento con toxina botulínica Frey syndrome secondary to submaxillectomy and botulinic treatment  

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Full Text Available El síndrome de Frey (SF se caracteriza por rubor, calor y sudación en la región maseterina y geniana durante las comidas. El SF se observa en el 20-60% de los pacientes sometidos a parotidectomía. Presentamos un caso con SF secundario a la ablación de la glándula submaxilar en un varón de 30 años de edad, sin antecedentes patológicos, que consultó en el año 2000 por adenopatía cervical izquierda. La misma fue biopsiada y la anatomía patológica informó carcinoma medular de tiroides. El paciente presentaba múltiples metástasis hepáticas y pulmonares, motivo por el cual recibió tratamiento quimioterápico con cisplatino plus doxorrubicina (seis ciclos con respuesta completa, finalizando dicho esquema en marzo del 2002. En julio del 2002 se realizó tiroidectomía total más vaciamiento ganglionar izquierdo con resección de la glándula submaxilar. Durante la cirugía se lesionó la rama mentoniana del nervio cervicofacial, rama del VII par craneal. En septiembre del 2004 consultó por episodios de sudación durante las comidas en la región submaxilar izquierda. Se realizó prueba de Minor y luego se procedió a aplicar toxina botulínica tipo A en la región afectada, a razón de 2.5 UI por punto (cm², a un total de 17 puntos. El control a los 21 días demostró más de un 95% de efectividad en la resolución del SF. El efecto duró un año, y una segunda reinfiltración mostró similar respuesta. No hallamos descripciones anteriores de SF en región submaxilar; se presenta su tratamiento satisfactorio con toxina botulínica tipo A.A case of Frey syndrome (FS secondary to submaxillar gland exeresis is presented and the results of the treatment with botulinum toxin (BTX type A. FS is a condition of sweating cheek and preauricular area during mealtime as a sequel detected in about 20-60% of patients after parotidectomy. The clinical symptoms include swelling, flushing and hyperhidrosis. The treatment choice for this condition is intracutaneous injection of BTX type A which blocks acetylcholine release at the sweat glands. A 30-year-old man, with thyroid medullar carcinoma diagnosed in 2002 received 6 cicles of cisplatin plus doxorubicin previous to the thyroidectomy with anterolateral neck dissection. During surgery the left ramus marginalis mandibulae was damaged. Two years later the patient referred sweating in submaxillar region during meals. CT scan demonstrated the absence of left submaxillar gland. Minor's test disclosed the affected area and BTX type A was injected (2.5 U/cm²/17 points. A twenty-one-day control showed a 95% reduction of the affected skin area. Persistent efficacy was observed up to one year followup time when he was reinjected. The FS, also known as "gustatory hyperhidrosis", was probably first reported by M. Duphenix in 1757. Lucja Frey considered its physiopathology as a disorder of both sympathetic and parasympathetic innervation. In our case the FS was caused by a misdirected regeneration of postganglionic parasympathetic nerve fibers that arrised from the nervus lingualis rami ganglionares of the nervus trigeminus. After nerve injury the colinergic parasympathetic fibers seek out colinergic receptors -sympathetic receptors of the skin- innervating sweat glands and small skin vessels. All previous cases were located at masseter region post-parotidectomy. We have not found any description of FS in the submaxillary region. The self-assessed efficacy of the treatment with a hyperhidrosis disease severity scale revealed a very satisfied patient at 20 months follow-up after being injected twice with BTX type A.

Alejandra Baéz

2007-10-01

340

Síndrome de Frey por submaxilectomía y tratamiento con toxina botulínica / Frey syndrome secondary to submaxillectomy and botulinic treatment  

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Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish El síndrome de Frey (SF) se caracteriza por rubor, calor y sudación en la región maseterina y geniana durante las comidas. El SF se observa en el 20-60% de los pacientes sometidos a parotidectomía. Presentamos un caso con SF secundario a la ablación de la glándula submaxilar en un varón de 30 años d [...] e edad, sin antecedentes patológicos, que consultó en el año 2000 por adenopatía cervical izquierda. La misma fue biopsiada y la anatomía patológica informó carcinoma medular de tiroides. El paciente presentaba múltiples metástasis hepáticas y pulmonares, motivo por el cual recibió tratamiento quimioterápico con cisplatino plus doxorrubicina (seis ciclos) con respuesta completa, finalizando dicho esquema en marzo del 2002. En julio del 2002 se realizó tiroidectomía total más vaciamiento ganglionar izquierdo con resección de la glándula submaxilar. Durante la cirugía se lesionó la rama mentoniana del nervio cervicofacial, rama del VII par craneal. En septiembre del 2004 consultó por episodios de sudación durante las comidas en la región submaxilar izquierda. Se realizó prueba de Minor y luego se procedió a aplicar toxina botulínica tipo A en la región afectada, a razón de 2.5 UI por punto (cm²), a un total de 17 puntos. El control a los 21 días demostró más de un 95% de efectividad en la resolución del SF. El efecto duró un año, y una segunda reinfiltración mostró similar respuesta. No hallamos descripciones anteriores de SF en región submaxilar; se presenta su tratamiento satisfactorio con toxina botulínica tipo A. Abstract in english A case of Frey syndrome (FS) secondary to submaxillar gland exeresis is presented and the results of the treatment with botulinum toxin (BTX) type A. FS is a condition of sweating cheek and preauricular area during mealtime as a sequel detected in about 20-60% of patients after parotidectomy. The cl [...] inical symptoms include swelling, flushing and hyperhidrosis. The treatment choice for this condition is intracutaneous injection of BTX type A which blocks acetylcholine release at the sweat glands. A 30-year-old man, with thyroid medullar carcinoma diagnosed in 2002 received 6 cicles of cisplatin plus doxorubicin previous to the thyroidectomy with anterolateral neck dissection. During surgery the left ramus marginalis mandibulae was damaged. Two years later the patient referred sweating in submaxillar region during meals. CT scan demonstrated the absence of left submaxillar gland. Minor's test disclosed the affected area and BTX type A was injected (2.5 U/cm²/17 points). A twenty-one-day control showed a 95% red