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Sample records for ganglionar por rickettsia

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

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

    1990-01-01

    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 r...

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

    Ismael A. Conti-Diaz

    1990-10-01

    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.

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

    Alfredo Seijo

    2007-12-01

    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.

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

    Ismael A. Conti-Díaz

    2009-12-01

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

  5. 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

    Roberta Santos Toledo

    2011-06-01

    Full Text Available 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.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 Rickettsiae 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

  6. Varizes ganglionares: fisiopatologia e aspectos ecográficos

    Rosado, E; Cabral, P; Pinto, E.; Penha, D; Paixão, P; Germano, A

    2012-01-01

    INTRODUÇÃO: As veias gânglionares presentes no triângulo femoral constituem uma rede venosa subcutânea que liga vários pontos do sistema venoso superficial e profundo. A dilatação desta rede venosa pode ser causa de insuficiência do sistema venoso superficial ou, mais frequentemente, estar envolvida no processo de recorrência varicosa pós-safenectomia. OBJECTIVOS: Descrever os aspectos anatómicos e fisiológicos da rede venosa ganglionar do triângulo femoral, alertando para uma causa pouco...

  7. Tropism and pathogenicity of rickettsiae.

    Uchiyama, Tsuneo

    2012-01-01

    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

  8. Tropism and pathogenicity of rickettsiae

    Tsuneo eUchiyama

    2012-06-01

    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.

  9. Rickettsia parkeri in Argentina

    Nava, Santiago; Elshenawy, Yasmin; Eremeeva, Marina E.; Sumner, John W.; Mastropaolo, Mariano; Paddock, Christopher D.

    2008-01-01

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

  10. Tropism and Pathogenicity of Rickettsiae

    Tsuneo eUchiyama

    2012-01-01

    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 ...

  11. Rickettsia spp. in Ticks, Poland

    Chmielewski, Tomasz; Podsiadly, Edyta; Karbowiak, Grzegorz; Tylewska-Wierzbanowska, Stanislawa

    2009-01-01

    Ticks are recognized as the main vectors and reservoirs of spotted fever group rickettsiae. We searched for the most prevalent Rickettsia spp. in Poland and found R. slovaca and R. helvetica bacteria in ticks in southern and central Poland; R. raoulti was found in ticks in all parts of Poland.

  12. Immunoproteomic profiling of Rickettsia parkeri and Rickettsia amblyommii.

    Pornwiroon, Walairat; Bourchookarn, Apichai; Paddock, Christopher D; Macaluso, Kevin R

    2015-09-01

    Rickettsia parkeri is an Amblyomma-associated, spotted fever group Rickettsia species that causes an eschar-associated, febrile illness in multiple countries throughout the Western Hemisphere. Many other rickettsial species of known or uncertain pathogenicity have been detected in Amblyomma spp. ticks in the Americas, including Rickettsia amblyommii, "Candidatus Rickettsia andeanae" and Rickettsia rickettsii. In this study, we utilized an immunoproteomic approach to compare antigenic profiles of low-passage isolates of R. parkeri and R. amblyommii with serum specimens from patients with PCR- and culture-confirmed infections with R. parkeri. Five immunoreactive proteins of R. amblyommii and nine immunoreactive proteins of R. parkeri were identified by matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry. Four of these, including the outer membrane protein (Omp) A, OmpB, translation initiation factor IF-2, and cell division protein FtsZ, were antigens common to both rickettsiae. Serum specimens from patients with R. parkeri rickettsiosis reacted specifically with cysteinyl-tRNA synthetase, DNA-directed RNA polymerase subunit alpha, putative sigma (54) modulation protein, chaperonin GroEL, and elongation factor Tu of R. parkeri which have been reported as virulence factors in other bacterial species. Unique antigens identified in this study may be useful for further development of the better serological assays for diagnosing infection caused by R. parkeri. PMID:26234571

  13. 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

    Nathalie C. Cunha

    2009-02-01

    Full Text Available The Brazilian Spotted Fever (BSF is a zoonotic disease caused by Rickettsia rickettsii and transmitted by ticks of the genus Amblyomma, more frequently, Amblyomma cajennense. The aim of this paper was to report the first molecular detection of R. rickettsii on R. sanguineus naturally infected in Rio de Janeiro, Brazil. Ticks were collected from dogs in a rural region of Resende municipality, Rio de Janeiro State, Brazil (22º30'9.46"S, 44º42'44.29"WO, where occurred five human cases of BSF in 2006. The ticks were identified under a stereoscopic microscope and separated in pools by stages, species and sex. DNA extraction was carried out using QIAamp DNA Mini Kit (QIAGEN®. The DNA was submitted to PCR amplification using 04 set of primers: Rr190.70p/Rr190.602n (OmpA, 532bp, BG1-21/BG2-20 (OmpB, 650bp, Tz15/Tz16 (17 kDa protein-encoding gene, 246bp and RpCS.877p/RpCS.1258n (gltA, 381bp. PCR products were separated by electrophoresis on 1% agarose gels and visualized under ultraviolet light with ethidium bromide. PCR products of the expected sizes were purified by QIAquick® and sequenced by ABI PRISM®. The generated nucleotide sequences were edited with using Bioedit® software and compared with the corresponding homologous sequences available through GenBank, using Discontiguous Mega Blast (http://www.ncbi.nlm.nih.gov. It was confirmed R. rickettsii by sequencing of the material (GenBank FJ356230. The molecular characterization of R. rickettsii in the tick R. sanguineus emphasizes the role of dogs as carriers of ticks from the environment to home. Moreover, this result suggests that there is a considerable chance for active participation of R. sanguineus as one of tick species in the transmission of R. ricketsii to human being in the Brazilian territory.A Febre Maculosa Brasileira (FMB é uma zoonose causada por Rickettsia rickettsii e transmitida por carrapatos do gênero Amblyomma, mais freqüentemente pela espécie Amblyomma cajennense. Este

  14. Rickettsiae in Gulf Coast Ticks, Arkansas, USA

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

    2010-01-01

    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.

  15. Epidemiología de rickettsiosis por Rickettsia parkeri y otras especies emergentes o re-emergentes asociadas a la antropización en Latinoamérica

    José M Venzal

    2013-07-01

    Full Text Available Se describe la importancia regional de Rickettsia parkeri y sus respectivos vectores. Se hace énfasis en los factores de antropización que favorecen la aparición de hospedadores alternativos para las garrapatas en los entornos domésticos y peridomésticos, generando modificaciones en la epidemiología del agente etiológico. También se menciona las modificaciones ecológicas que pueden favorecen el incremento de poblaciones de reservorios para las garrapatas incrementando el riesgo para el ser humano de sufrir enfermedades rickettsiales.

  16. Epidemiología de rickettsiosis por Rickettsia parkeri y otras especies emergentes o re-emergentes asociadas a la antropización en Latinoamérica

    Venzal, José M.

    2013-01-01

    Se describe la importancia regional de Rickettsia parkeri y sus respectivos vectores. Se hace énfasis en los factores de antropización que favorecen la aparición de hospedadores alternativos para las garrapatas en los entornos domésticos y peridomésticos, generando modificaciones en la epidemiología del agente etiológico. También se menciona las modificaciones ecológicas que pueden favorecen el incremento de poblaciones de reservorios para las garrapatas incrementando el riesgo para el ser hu...

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

    Rosa Mostorino E

    2003-03-01

    Full Text Available 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 cefalea, 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.

  18. Rickettsia helvetica in Dermacentor reticulatus Ticks

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

    2009-01-01

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

  19. Bacterial small RNAs in the Genus Rickettsia

    Schroeder, Casey L. C.; Narra, Hema P.; Rojas, Mark; Sahni, Abha; Patel, Jignesh; Khanipov, Kamil; Wood, Thomas G.; Fofanov, Yuriy; Sahni, Sanjeev K.

    2015-01-01

    Background Rickettsia species are obligate intracellular Gram-negative pathogenic bacteria and the etiologic agents of diseases such as Rocky Mountain spotted fever (RMSF), Mediterranean spotted fever, epidemic typhus, and murine typhus. Genome sequencing revealed that R. prowazekii has ~25 % non-coding DNA, the majority of which is thought to be either “junk DNA” or pseudogenes resulting from genomic reduction. These characteristics also define other Rickettsia genomes. Bacterial small RNAs,...

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

    F. Espín

    2010-03-01

    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

  1. Valoración probabilística de un estadio ganglionar negativo tras cirugía de resección en el cáncer de colon. Repercusiones ante una alta probabilidad de error.

    Martínez Ramos, David

    2008-01-01

    RESUMEN INTRODUCCIÓN. El estudio ganglionar en el cáncer de colon puede considerarse como una prueba diagnóstica, en la cual se obtiene un resultado binario (ganglios positivos o negativos). Utilizando el teorema de Bayes (TB) puede calcularse la probabilidad de afectación ganglionar cuando el estudio anatomopatológico ha resultado negativo, es decir, puede calcularse la probabilidad final de error (PFE) ante un estadio ganglionar negativo. En función de la PFE que se considere aceptable y...

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

    Heloisa Helena Barbosa Melles

    1999-10-01

    Full Text Available Embora o diagnóstico da febre maculosa baseie-se em sinais e sintomas característicos, o mesmo requer confirmação laboratorial, pois existem alguns diagnósticos diferenciais possíveis como meningococcemia, leptospirose, infecção por enterovírus e febre tifóide. A confirmação laboratorial pode ser feita através da pesquisa de anticorpos específicos, possível somente alguns dias após o aparecimento da doença, através do isolamento do agente em amostras de sangue e/ou biópsia de pele, e ainda, de amostras de carrapatos coletados do paciente ou de animais reservatório. O isolamento a partir de sangue ou biópsia de pele resulta em diagnóstico precoce da doença, pois na fase de rickettsemia ainda não há anticorpos detectáveis no sangue. Assim, com o objetivo de facilitar o diagnóstico precoce da febre maculosa, estabelecemos um método de isolamento de rickettsia em cultura de células vero. Para a padronização foi inoculada amostra padrão de Rickettsia rickettsii, cepa Sheyla Smith, cedida pelo CDC. A identificação foi feita através da reação de imunofluorescência indireta. A presença de microrganismos verdes fluorescentes visualizados no interior do citoplasma das células caracterizou o crescimento do agente. Posteriormente, a metodologia foi confirmada pelo isolamento do agente da febre maculosa em amostras de biópsia de pele de paciente proveniente de área endêmica no Estado de São Paulo, bem como, de amostras de carrapato do gênero Amblyomma, considerado o reservatório e transmissor da doença no Brasil.The diagnosis of spotted fever is based on characteristic signs and symptoms but requires laboratorial confirmation because of the possible differencial diagnosis from other diseases like leptospirosis, enterovirosis, meningococcemia and tiphoid fever. Laboratorial confirmation may be done by detection of specific antibodies which is possible only 5-10 days after the onset of the symptoms or by the

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

    Tian Zhan-Cheng

    2012-01-01

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

  4. Rickettsia slovaca Infection in Humans, Portugal

    De Sousa, R.; Pereira, B. I.; Nazareth, C.; Cabral, S.; Ventura, C.; Crespo, P; Marques, N; Cunha, S

    2013-01-01

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

  5. Rickettsia mongolotimonae Infection in South Africa

    Pretorius, Anne-Marié; Birtles, Richard J.

    2004-01-01

    We report the first laboratory-confirmed case of Rickettsia mongolotimonae infection in Africa. The patient sought treatment for an eschar on his toe; lymphangitis, severe headaches, and fever subsequently developed. After a regimen of doxycycline, symptoms rapidly resolved. R. mongolotimonae infection was diagnosed retrospectively by serologic tests and molecular-based detection of the organism in biopsy specimens of eschar material.

  6. Rickettsia parkeri Infection after Tick Bite, Virginia

    Whitman, Timothy J.; Richards, Allen L.; Paddock, Christopher D.; Tamminga, Cindy L.; Sniezek, Patrick J.; Jiang, Ju; Byers, David K.; Sanders, John W.

    2007-01-01

    We describe a man with a febrile illness and an eschar that developed at the site of a tick bite. Rickettsia parkeri was detected and isolated from the eschar. This report represents the second documented case of R. parkeri rickettsiosis in a US serviceman in eastern Virginia.

  7. Rickettsia felis in Xenopsylla cheopis, Java, Indonesia

    Jiang, Ju; Soeatmadji, Djoko W.; Henry, Katherine M; Ratiwayanto, Sutanti; Michael J. Bangs; Richards, Allen L.

    2006-01-01

    Rickettsia typhi and R. felis, etiologic agents of murine typhus and fleaborne spotted fever, respectively, were detected in Oriental rat fleas (Xenopsylla cheopis) collected from rodents and shrews in Java, Indonesia. We describe the first evidence of R. felis in Indonesia and naturally occurring R. felis in Oriental rat fleas.

  8. Detection of Rickettsia and Anaplasma from hard ticks in Thailand.

    Malaisri, Premnika; Hirunkanokpun, Supanee; Baimai, Visut; Trinachartvanit, Wachareeporn; Ahantarig, Arunee

    2015-12-01

    We collected a total of 169 adult hard ticks and 120 nymphs from under the leaves of plants located along tourist nature trails in ten localities. The results present data examining the vector competence of ticks of different genera and the presence of Rickettsia and Anaplasma species. The ticks belonged to three genera, Amblyomma, Dermacentor, and Haemaphysalis, comprising 11 species. Rickettsia bacteria were detected at three collection sites, while Anaplasma bacteria were detected at only one site. Phylogenetic analysis revealed new rickettsia genotypes from Thailand that were closely related to Rickettsia tamurae, Rickettsia monacensis, and Rickettsia montana. This study was also the first to show that Anaplasma bacteria are found in Haemaphysalis shimoga ticks and are closely related evolutionarily to Anaplasma bovis. These results provide additional information for the geographical distribution of tick species and tick-borne bacteria in Thailand and can therefore be applied for ecotourism management. PMID:26611960

  9. Rickettsia influences thermotolerance in the whitefly Bemisia tabaci B biotype

    Marina Brumin; Svetlana Kontsedalov; Murad Ghanim

    2011-01-01

    The whitefly Bemisia tabaci harbors Portiera aleyrodidarum,an obligatory symbiotic bacterium,as well as several secondary symbionts,including Rickettsia,Hamiltonella,Wolbachia,Arsenophonus,Cardinium and Fritschea,the function of which is unknown.In Israel,Rickettsia is found in both the B and Q of B.tabaci biotypes,and while all other secondary symbionts are located in the bacteriomes,Rickettsia can occupy most of the body cavity of the insect.We tested whether Rickettsia influences the biology of B.tabaci and found that exposing a Rickettsia-containing population to increasing temperatures significantly increases its tolerance to heat shock that reached 40℃,compared to a Rickettsia-free population.This increase in tolerance to heat shock was not associated with specific induction of heat-shock protein gene expression; however,it was associated with eduction in Rickettsia numbers as was assessed by quantitative real-time polymerase chain reaction and fluorescence in situ hybridization analyses.To assess the causes for thermotolerance when ickettsia is reduced,we tested whether its presence is associated with the induction of genes required for thermotolerance.We found that under normal 25℃ rearing temperature,genes associated with response to stress such as cytoskeleton genes are induced in the Rickettsia-containing population.Thus,the presence of Rickettsia in B.tabaci under normal conditions induces the expression of genes required for thermotolerance that under high temperatures indirectly lead to this tolerance.

  10. Rickettsia conorii transcriptional response within inoculation eschar

    Renesto, Patricia; Rovery, Clarisse; Schrenzel, Jacques; Leroy, Quentin; Huyghe, Antoine; Li, Wenjun; Lepidi, Hubert; Francois, Patrice; Raoult, Didier

    2008-01-01

    BACKGROUND: Rickettsia conorii, the causative agent of the Mediterranean spotted fever, is transmitted to humans by the bite of infected ticks Rhipicephalus sanguineus. The skin thus constitutes an important barrier for the entry and propagation of R. conorii. Given this, analysis of the survival strategies used by the bacterium within infected skin is critical for our understanding of rickettsiosis. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the first genome-wide analysis of R. conorii ...

  11. Permeability of Rickettsia prowazekii to NAD

    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

  12. Plasmids and rickettsial evolution: insight from Rickettsia felis.

    Joseph J Gillespie

    Full Text Available BACKGROUND: The genome sequence of Rickettsia felis revealed a number of rickettsial genetic anomalies that likely contribute not only to a large genome size relative to other rickettsiae, but also to phenotypic oddities that have confounded the categorization of R. felis as either typhus group (TG or spotted fever group (SFG rickettsiae. Most intriguing was the first report from rickettsiae of a conjugative plasmid (pRF that contains 68 putative open reading frames, several of which are predicted to encode proteins with high similarity to conjugative machinery in other plasmid-containing bacteria. METHODOLOGY/PRINCIPAL FINDINGS: Using phylogeny estimation, we determined the mode of inheritance of pRF genes relative to conserved rickettsial chromosomal genes. Phylogenies of chromosomal genes were in agreement with other published rickettsial trees. However, phylogenies including pRF genes yielded different topologies and suggest a close relationship between pRF and ancestral group (AG rickettsiae, including the recently completed genome of R. bellii str. RML369-C. This relatedness is further supported by the distribution of pRF genes across other rickettsiae, as 10 pRF genes (or inactive derivatives also occur in AG (but not SFG rickettsiae, with five of these genes characteristic of typical plasmids. Detailed characterization of pRF genes resulted in two novel findings: the identification of oriV and replication termination regions, and the likelihood that a second proposed plasmid, pRFdelta, is an artifact of the original genome assembly. CONCLUSION/SIGNIFICANCE: Altogether, we propose a new rickettsial classification scheme with the addition of a fourth lineage, transitional group (TRG rickettsiae, that is unique from TG and SFG rickettsiae and harbors genes from possible exchanges with AG rickettsiae via conjugation. We offer insight into the evolution of a plastic plasmid system in rickettsiae, including the role plasmids may have played in

  13. Caracterización de las células ganglionares de la retina melanopsínicas y estudio de la degeneración y neuroprotección de las células ganglionares de la retina en el roedor

    Galindo Romero, Caridad

    2014-01-01

    Objetivos Caracterizar la población de células ganglionares de la retina melanopsínicas (CGRm) en la rata adulta en relación con la población total de células ganglionares de la retina (CGR) y analizar su distribución espacial en la retina. Caracterizar si el Brn3a es un buen marcador de las CGR en ratones albino (Swiss) y pigmentado (C57BL/6). Analizar la curva temporal de muerte de las CGR de ratón después de la sección del nervio óptico (SNO), y evaluar el efecto neuroprotector del ...

  14. Rickettsia and Bartonella Species in Fleas from Reunion Island

    Dieme, Constentin; Parola, Philippe; Guernier, Vanina; Lagadec, Erwan; Le Minter, Gildas; Balleydier, Elsa; Pagès, Frederic; Dellagi, Koussay; Tortosa, Pablo; Raoult, Didier; Socolovschi, Cristina

    2015-01-01

    Rickettsia felis, Rickettsia typhi, and Bartonella DNA was detected by molecular tools in 12% of Rattus rattus fleas (Xenopsylla species) collected from Reunion Island. One-third of the infested commensal rodents captured during 1 year carried at least one infected flea. As clinical signs of these zoonoses are non-specific, they are often misdiagnosed. PMID:25646263

  15. Detecting Rickettsia parkeri Infection from Eschar Swab Specimens

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

    2013-01-01

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

  16. Riesgo de recurrencia ganglionar y valoración evolutiva en pacientes con carcinoma de mama en estadios precoces y sometidas a la biopsia selectiva del ganglio centinela

    Domènech Vilardell, Anna

    2011-01-01

    ANTECEDENTES DEL TEMA: El estado ganglionar axilar es el factor pronóstico más importante para determinar la supervivencia y la recurrencia en el carcinoma de mama, puesto que es conocido que la afectación axilar en estas pacientes, disminuye la supervivencia a los 5 años del 85-95 % al 55-70 % y conlleva a que presenten metástasis a distancia con más frecuencia . De todos modos, la introducción y amplia utilización del cribado mamográfico está aumentando la detección de tumores incipientes ...

  17. Dynamics of the endosymbiont Rickettsia in an insect pest.

    Cass, Bodil N; Yallouz, Rachel; Bondy, Elizabeth C; Mozes-Daube, Netta; Horowitz, A Rami; Kelly, Suzanne E; Zchori-Fein, Einat; Hunter, Martha S

    2015-07-01

    A new heritable bacterial association can bring a fresh set of molecular capabilities, providing an insect host with an almost instantaneous genome extension. Increasingly acknowledged as agents of rapid evolution, inherited microbes remain underappreciated players in pest management programs. A Rickettsia bacterium was tracked sweeping through populations of an invasive whitefly provisionally described as the "B" or "MEAM1" of the Bemisia tabaci species complex, in the southwestern USA. In this population, Rickettsia provides strong fitness benefits and distorts whitefly sex ratios under laboratory conditions. In contrast, whiteflies in Israel show few apparent fitness benefits from Rickettsia under laboratory conditions, only slightly decreasing development time. A survey of B. tabaci B samples revealed the distribution of Rickettsia across the cotton-growing regions of Israel and the USA. Thirteen sites from Israel and 22 sites from the USA were sampled. Across the USA, Rickettsia frequencies were heterogeneous among regions, but were generally very high, whereas in Israel, the infection rates were lower and declining. The distinct outcomes of Rickettsia infection in these two countries conform to previously reported phenotypic differences. Intermediate frequencies in some areas in both countries may indicate a cost to infection in certain environments or that the frequencies are in flux. This suggests underlying geographic differences in the interactions between bacterial symbionts and this serious agricultural pest. PMID:25626393

  18. Identificación molecular y análisis de la relación filogenética de especies de Rickettsias presentes en garrapatas provenientes de tres regiones de Colombia

    Ramírez Hernández, Alejandro

    2014-01-01

    Las Rickettsiosis son enfermedades emergentes zoonóticas asociadas a artrópodos. Éstas son producidas por la infección de bacterias del género Rickettsia (Da Rocha-Lima, 1916) las cuales son alfa-proteobacterias que se caracterizan por ser parásitos intracelulares obligados y porque pueden desencadenar enfermedad febril inespecífica en humanos y animales, las cuales, si no son diagnosticadas y tratadas de forma oportuna pueden tener un desenlace fatal. En su ciclo biológico, las rickettsias d...

  19. Progress in the insect symbiont Rickettsia%昆虫共生细菌 Rickettsia 的研究进展

    潘慧鹏; 张友军

    2012-01-01

    Rickettsia是传播和引起人类与其他脊椎动物疾病的胞内共生菌.引起脊椎动物疾病的这些Rickettsia,其部分生活史是在节肢动物体内完成的;而另外许多Rickettsia,其整个生活史都是在宿主节肢动物体内完成.为了叙述方便,把前者称为脊椎动物Rickettsia,后者称为节肢动物Rickettsia.过去的研究主要集中在医学上具有重大意义的脊椎动物Rickettsia,而关于节肢动物Rickettsia的生物学特性等研究则相对较少.近年来,研究者们加大了对昆虫Rickettsia的研究,发现昆虫Rickettsia广泛分布于昆虫中,且有两种存在形式.其可以通过垂直卵传的方式在世代间传递,也可以通过寄生蜂和寄主植物达到在昆虫之间传播的目的.昆虫Rickettsia可通过诱导孤雌生殖、诱导杀雄等方式影响宿主的生殖行为.其对不同宿主昆虫可产生对宿主有利或有害的作用;可增强宿主昆虫抵御高温和寄生蜂的能力,与宿主昆虫对药剂的敏感性相关.最后,昆虫Rickettsia具有一个简化的基因组,且存在进一步减小的可能性.%Rickettsia species are intracellular symbionts of eukaryotes that are well known for infecting and causing serious diseases in humans and other vertebrates. All known vertebrate associated Rickettsia bacteria are vectored by arthropods as part of their life-cycle, and many other Rickettsia species are found exclusively in arthropods without any secondary host. For convenience, we refer to the former as vertebrate Rickettsia and the latter as arthropod Rickettsia. Previous research efforts mainly focused on medically important vertebrate Rickettsia. The biological studies of arthropod Rickettsia were limited- In recent years, more efforts have been made on the insect symbiont Rickettsia and considerable achievements have been obtained. The insect symbiont Rickettsia is distributed among insects, and two different localization patterns exist in the same insect

  20. Rickettsia felis Infection in a Common Household Insect Pest, Liposcelis bostrychophila (Psocoptera: Liposcelidae)▿ †

    Behar, Adi; McCormick, Laurie J.; Perlman, Steve J.

    2010-01-01

    Many species of Rickettsia are well-known mammalian pathogens transmitted by blood-feeding arthropods. However, molecular surveys are continually uncovering novel Rickettsia species, often in unexpected hosts, including many arthropods that do not feed on blood. This study reports a systematic molecular characterization of a Rickettsia infecting the psocid Liposcelis bostrychophila (Psocoptera: Liposcelidae), a common and cosmopolitan household pest. Surprisingly, the psocid Rickettsia is sho...

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

    Hamza Leulmi

    2014-10-01

    Full Text Available 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.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.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.

  2. Widespread Rickettsia spp. Infections in Ticks (Acari: Ixodoidea) in Taiwan.

    Kuo, Chi-Chien; Shu, Pei-Yun; Mu, Jung-Jung; Lee, Pei-Lung; Wu, Yin-Wen; Chung, Chien-Kung; Wang, Hsi-Chieh

    2015-09-01

    Ticks are second to mosquitoes as the most important disease vectors, and recent decades have witnessed the emergence of many novel tick-borne rickettsial diseases, but systematic surveys of ticks and tick-borne rickettsioses are generally lacking in Asia. We collected and identified ticks from small mammal hosts between 2006 and 2010 in different parts of Taiwan. Rickettsia spp. infections in ticks were identified by targeting ompB and gltA genes with nested polymerase chain reaction. In total, 2,732 ticks were collected from 1,356 small mammals. Rhipicephalus haemaphysaloides Supino (51.8% of total ticks), Haemaphysalis bandicota Hoogstraal & Kohls (28.0%), and Ixodes granulatus Supino (20.0%) were the most common tick species, and Rattus losea Swinhoe (44.7% of total ticks) and Bandicota indica Bechstein (39.9%) were the primary hosts. The average Rickettsia infective rate in 329 assayed ticks was 31.9% and eight Rickettsia spp. or closely related species were identified. This study shows that rickettsiae-infected ticks are widespread in Taiwan, with a high diversity of Rickettsia spp. circulating in the ticks. Because notifiable rickettsial diseases in Taiwan only include mite-borne scrub typhus and flea-borne murine typhus, more studies are warranted for a better understanding of the real extent of human risks to rickettsioses in Taiwan. PMID:26336223

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

    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)

  4. A Case of Human Infection by Rickettsia slovaca in Greece.

    Kostopoulou, Vasiliki; Chochlakis, Dimosthenis; Kanta, Chrysoula; Katsanou, Andromachi; Rossiou, Konstantina; Rammos, Aidonis; Papadopoulos, Spyridon-Filippos; Katsarou, Theodora; Tselentis, Yannis; Psaroulaki, Anna; Boukas, Chrysostomos

    2016-07-22

    Although tick-borne rickettsiosis is endemic in Greece, until recently, human samples arriving at the National Reference Centre under suspicion of rickettsial infection were routinely tested only for Rickettsia typhi and R. conorii. However, identification of additional rickettsia species in ticks prompted revision of the protocol in 2010. Until that year, all human samples received by the laboratory were tested for antibodies against R. conorii and R. typhi only. Now, tests for R. slovaca, R. felis, and R. mongolotimonae are all included in routine analysis. The current description of a human R. slovaca case is possible as a result of these changes in routine testing. PMID:26370429

  5. Intraocular inflammation as the main manifestation of Rickettsia conorii infection

    Orduña A

    2011-09-01

    Full Text Available Archimedes LD Agahan1,3, Jenice Torres1, Graciana Fuentes-Páez1, Hernan Martínez-Osorio1, Antonio Orduña2, Margarita Calonge11Ocular Immunology and Uveitis Unit, Institute of Applied Ophthalmobiology (IOBA, 2Microbiology Department, University of Valladolid, Valladolid, Spain; 3Department of Ophthalmology and Visual Sciences, University of the Philippines, Philippine General Hospital, Manila, PhilippinesObjective: To report the clinical features and management of seven cases of intraocular inflammation caused by Rickettsia infection and review published literature.Methods: Rickettsia conorii or Rickettsia spp. infection was diagnosed based on the following criteria: (1 positive serology according to the European Guidelines, (2 titer normalization after specific treatment, and (3 complete resolution of ophthalmic disease and accompanying symptoms after antibiotic therapy.Results: Seven patients were referred for uveitis of unknown etiology. All came from regions where Mediterranean spotted fever is prevalent. One patient met the European guidelines criteria for Rickettsia spp. infection, while the other six cases met the criteria for R. conorii infection. The main symptoms were visual loss, floaters, eye redness, photophobia, and ocular pain. Predominant ophthalmic signs included vasculitis, choroiditis, vitritis, and macular edema. All patients required antibiotic treatment that resulted in the remission of the infection. Doxycycline was the first choice and the only antibiotic used to treat four patients. One patient needed ciprofloxacin as a second antibiotic after not responding to doxycycline. Two patients had doxycycline as a second antibiotic after not responding primarily to sulfonamides (which had been given after 2–3 days of doxycycline gastric intolerance; one of these patients needed ciprofloxacin as a third antibiotic.Conclusion: Intraocular inflammation can occur as the main manifestation of Rickettsia conorii or Rickettsia spp

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

    Gaasenbeek Cor

    2009-09-01

    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.

  7. Detección de Rickettsia spp. en Suero y Garrapatas de Mamíferos Silvestres en Cautiverio en Montería, Córdoba -resumen-

    Dave Wehdeking-Hernández; Laura Hernández-Fernández; César Rojano-Bolaño; J Ruíz-Rodríguez

    2014-01-01

    Las rickettsiosis transmitidas por garrapatas son causadas por bacterias intracelulares pertenecientes al grupo de las fiebres manchadas del género Rickettsia. Estas zoonosis son algunas de las enfermedades transmitidas por vectores de más antiguo conocimiento‚ e incluyen dentro de su ciclo de transmisión diversas especies de mamíferos. No obstante‚ en Colombia existen pocos trabajos enfocados a conocer la dinámica de las rickettsiosis en animales silvestres. El objetivo de este estudio fue d...

  8. Genome Sequence of the Tick-Borne Pathogen Rickettsia raoultii.

    El Karkouri, Khalid; Mediannikov, Oleg; Robert, Catherine; Raoult, Didier; Fournier, Pierre-Edouards

    2016-01-01

    ITALIC! Rickettsia raoultiiis a tick-associated spotted fever group (SFG) organism, causing scalp eschar and neck lymphadenopathy after tick bite (SENLAT) in humans. We report here the genome sequence of ITALIC! R. raoultiistrain Khabarovsk(T)(CSUR R3(T), ATCC VR-1596(T)), which was isolated from a ITALIC! Dermacentor silvarumtick collected in Russia. PMID:27103706

  9. Genome Sequence of the Tick-Borne Pathogen Rickettsia raoultii

    El Karkouri, Khalid; Mediannikov, Oleg; Robert, Catherine; Raoult, Didier; Fournier, Pierre-Edouards

    2016-01-01

    Rickettsia raoultii is a tick-associated spotted fever group (SFG) organism, causing scalp eschar and neck lymphadenopathy after tick bite (SENLAT) in humans. We report here the genome sequence of R. raoultii strain KhabarovskT (CSUR R3T, ATCC VR-1596T), which was isolated from a Dermacentor silvarum tick collected in Russia.

  10. Rickettsia slovaca and R. raoultii in Tick-borne Rickettsioses

    Parola, Philippe; Rovery, Clarisse; Rolain, Jean Marc; Brouqui, Philippe; Davoust, Bernard; Raoult, Didier

    2009-01-01

    Tick-borne lymphadenopathy (TIBOLA), also called Dermacentor-borne necrosis erythema and lymphadenopathy (DEBONEL), is defined as the association of a tick bite, an inoculation eschar on the scalp, and cervical adenopathies. We identified the etiologic agent for 65% of 86 patients with TIBOLA/DEBONEL as either Rickettsia slovaca (49/86, 57%) or R. raoultii (7/86, 8%).

  11. 'Candidatus Rickettsia mendelii', a novel basal group rickettsia detected in Ixodes ricinus ticks in the Czech Republic.

    Hajduskova, Eva; Literak, Ivan; Papousek, Ivo; Costa, Francisco B; Novakova, Marketa; Labruna, Marcelo B; Zdrazilova-Dubska, Lenka

    2016-04-01

    A novel rickettsial sequence in the citrate synthase gltA gene indicating a novel Rickettsia species has been detected in 7 out of 4524 Ixodes ricinus ticks examined within several surveys performed in the Czech Republic from 2005 to 2009. This new Candidatus Rickettsia sp. sequence has been found in 2 nymphs feeding on wild birds (Luscinia megarhynchos and Erithacus rubecula), in a male tick from vegetation, and 4 ticks feeding on a dog (3 males, 1 female tick). Portions of the ompA, ompB, sca4, and htrA genes were not amplifiable in these samples. A maximum likelihood tree of rickettsiae based on comparisons of partial amino acid sequences of citrate synthase and nucleotide sequences of 16S rDNA genes and phylogenetic analysis revealed a basal position of the novel species in the proximity of R. bellii and R. canadensis. The novel species has been named 'Candidatus Rickettsia mendelii' after the founder of genetics, Gregor Mendel. PMID:26873811

  12. Mechanisms of Rickettsia parkeri invasion of host cells and early actin-based motility

    Reed, Shawna

    2012-01-01

    Rickettsiae are obligate intracellular pathogens that are transmitted to humans by arthropod vectors and cause diseases such as spotted fever and typhus. Spotted fever group (SFG) Rickettsia hijack the host actin cytoskeleton to invade, move within, and spread between eukaryotic host cells during their obligate intracellular life cycle. Rickettsia express two bacterial proteins that can activate actin polymerization: RickA activates the host actin-nucleating Arp2/3 complex while Sca2 directly...

  13. Conjugation genes are common throughout the genus Rickettsia and are transmitted horizontally

    Weinert, Lucy A.; Welch, John J.; Jiggins, Francis M.

    2009-01-01

    Rickettsia are endosymbionts of arthropods, some of which are vectored to vertebrates where they cause disease. Recently, it has been found that some Rickettsia strains harbour conjugative plasmids and others encode some conjugative machinery within the bacterial genome. We investigated the distribution of these conjugation genes in a phylogenetically diverse collection of Rickettsia isolated from arthropods. We found that these genes are common throughout the genus and, in stark contrast to ...

  14. Detection of spotted fever group Rickettsia spp. from bird ticks in the U.K.

    Graham, R I; Mainwaring, M C; Du Feu, R

    2010-09-01

    Migratory birds are known to play a role in the long-distance transportation of microorganisms. To investigate whether this is true for rickettsial agents, we undertook a study to characterize tick infestation in populations of the migratory passerine bird Riparia riparia (Passeriformes: Hirundinidae), the sand martin. A total of 194 birds were sampled and ticks removed from infested birds. The ticks were identified as female Ixodes lividus (Acari: Ixodidae) using standard morphological and molecular techniques. Tick DNA was assayed to detect Rickettsia spp. using polymerase chain reaction and DNA was sequenced for species identification. A single Rickettsia spp. was detected in 100% of the ticks and was designated Rickettsia sp. IXLI1. Partial sequences of 17-kDa and ompA genes showed greatest similarity to Rickettsia sp. TCM1, an aetiological agent of Japanese spotted fever-like illness, previously described in Thailand. Phylogenetic analysis showed that Rickettsia sp. IXLI1 fitted neatly into a group containing strains Rickettsia japonica, Rickettsia sp. strain Davousti and Rickettsia heilongjiangensis. In conclusion, this research shows that U.K. migratory passerine birds host ticks infected with Rickettsia species and contribute to the geographic distribution of spotted fever rickettsial agents. PMID:20546129

  15. Rickettsia: an unusual cause of sepsis in the emergency department

    Chipp, E; Digby, S.

    2006-01-01

    Mediterranean spotted fever (caused by Rickettsia conorii) is one of the tick‐borne rickettsioses. It is prevalent in southern Europe, Africa and central Asia and may also be seen in travellers returning from these areas. It presents with various non‐specific symptoms, including fever, maculopapular rash, headache, myalgia or diarrhoea and vomiting. A visible eschar at the site of the tick bite is characteristic but not present in all cases. There is no test that reliably confirms the disease...

  16. A Patient from Argentina Infected with Rickettsia massiliae

    García-García, Juan Carlos; Portillo, Aránzazu; Núñez, Manuel J.; Santibáñez, Sonia; Castro, Begoña; Oteo, José A

    2010-01-01

    The first confirmed case of Rickettsia massiliae infection in the New World (Buenos Aires, Argentina) is described. To date, only two cases of human infection had been reported in Europe. The patient, a woman, had a fever, a palpable purpuric rash on the upper and lower extremities, and a skin lesion (eschar) on the right leg compatible with tache noire. When interviewed, she reported having had contact with dog ticks. After treatment with doxycycline for 12 days, her symptoms resolved. Ricke...

  17. Experimental Infection of Amblyomma aureolatum Ticks with Rickettsia rickettsii

    Labruna, Marcelo B.; Ogrzewalska, Maria; Soares, João F.; Martins, Thiago F.; Soares, Herbert S.; Moraes-Filho, Jonas; Nieri-Bastos, Fernanda A.; Almeida, Aliny P.; Pinter, Adriano

    2011-01-01

    We experimentally infected Amblyomma aureolatum ticks with the bacterium Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever (RMSF). These ticks are a vector for RMSF in Brazil. R. rickettsii was efficiently conserved by both transstadial maintenance and vertical (transovarial) transmission to 100% of the ticks through 4 laboratory generations. However, lower reproductive performance and survival of infected females was attributed to R. rickettsii infection. Therefore, ...

  18. Outbreaks of Rickettsia felis in Kenya and Senegal, 2010

    2010-06-09

    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.

  19. Rickettsia felis infection in cat fleas Ctenocephalides felis felis

    Mauricio C. Horta

    2010-10-01

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

  20. Spotted fever group rickettsiae detected in immature stages of ticks parasitizing on Iberian endemic lizard Lacerta schreiberi Bedriaga, 1878

    Kubelová, M.; Papoušek, I.; Bělohlávek, T.; Goüy de Bellocq, Joëlle; Baird, Stuart J. E.; Široký, P.

    2015-01-01

    Roč. 6, č. 6 (2015), s. 711-714. ISSN 1877-959X Institutional support: RVO:68081766 Keywords : Spotted fever group rickettsiae * Rickettsia monacensis * Rickettsia helvetica * Ixodes ricinus * Lacerta schreiberi Subject RIV: EG - Zoology Impact factor: 2.718, year: 2014

  1. High Prevalence of Rickettsia spp. Infections in Small Mammals in Taiwan

    Kuo, Chi-Chien; Shu, Pei-Yun; Mu, Jung-Jung

    2015-01-01

    Abstract Surveillance for Rickettsia spp. is urgently needed due to the recent emergence of many novel rickettsioses around the globe, but previous studies in Taiwan have been limited to small areas and no investigation of infections in vertebrate hosts has ever been attempted. We surveyed rickettsial infections systematically in small-mammal hosts trapped between 2006 and 2010 throughout Taiwan. Fragments of ompB and gltA genes in the liver, spleen, and kidney of mammals were targeted by nested polymerase chain reaction. We trapped 1375 individuals of 10 species, among which Rattus losea was the most common (54.6%), followed by Suncus murinus (20.6%) and Mus caroli (10.6%). The overall rate of Rickettsia infections in the liver, spleen, or kidney of 309 assayed small mammals was 60.5%, with a rate of infection ≥50% for each mammal species. DNA nucleotide sequences of 184 successfully sequenced genes were most similar to nine Rickettsia species: Rickettsia conorii, R. felis, R. japonica, R. raoultii, R. rickettsii, Rickettsia sp. IG-1, Rickettsia sp. TwKM01, Rickettsia sp. TwKM02, and R. typhi. Our results suggest that several novel Rickettsia spp. are common and widespread across various habitats throughout Taiwan and suggest the need for further study of emerging rickettsioses in Taiwan. PMID:25629776

  2. Rickettsia spp. in Seabird Ticks from Western Indian Ocean Islands, 2011–2012

    Dietrich, Muriel; Lebarbenchon, Camille; Jaeger, Audrey; Le Rouzic, Céline; Bastien, Matthieu; Lagadec, Erwan; McCoy, Karen D.; Pascalis, Hervé; Le Corre, Matthieu; Dellagi, Koussay; Tortosa, Pablo

    2014-01-01

    We found a diversity of Rickettsia spp. in seabird ticks from 6 tropical islands. The bacteria showed strong host specificity and sequence similarity with strains in other regions. Seabird ticks may be key reservoirs for pathogenic Rickettsia spp., and bird hosts may have a role in dispersing ticks and tick-associated infectious agents over large distances.

  3. Rickettsia felis Infection in a Common Household Insect Pest, Liposcelis bostrychophila (Psocoptera: Liposcelidae)▿ †

    Behar, Adi; McCormick, Laurie J.; Perlman, Steve J.

    2010-01-01

    Many species of Rickettsia are well-known mammalian pathogens transmitted by blood-feeding arthropods. However, molecular surveys are continually uncovering novel Rickettsia species, often in unexpected hosts, including many arthropods that do not feed on blood. This study reports a systematic molecular characterization of a Rickettsia infecting the psocid Liposcelis bostrychophila (Psocoptera: Liposcelidae), a common and cosmopolitan household pest. Surprisingly, the psocid Rickettsia is shown to be Rickettsia felis, a human pathogen transmitted by fleas that causes serious morbidity and occasional mortality. The plasmid from the psocid R. felis was sequenced and was found to be virtually identical to the one in R. felis from fleas. As Liposcelis insects are often intimately associated with humans and other vertebrates, it is speculated that they acquired R. felis from fleas. Whether the R. felis in psocids causes disease in vertebrates is not known and warrants further study. PMID:20139311

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

    Raoult Didier

    2006-02-01

    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

  5. Rickettsia felis infection in cat fleas Ctenocephalides felis felis

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

    2010-01-01

    The present study evaluated the rickettsial infection in a laboratory colony of cat fleas, Ctenocephalides felis felis (Bouche) in Brazil. All flea samples (30 eggs, 30 larvae, 30 cocoons, 30 males, and 30 females) tested by polymerase chain reaction (PCR) were shown to contain rickettsial DNA. PCR products, corresponding to the rickettsial gltA, htrA, ompA and ompB gene partial sequences were sequenced and showed to correspond to Rickettsia felis, indicating that the flea colony was 100% inf...

  6. Rickettsia felis, an emerging flea-transmitted human pathogen

    Abdad, Mohammad Yazid; Stenos, John; Graves, Stephen

    2011-01-01

    Rickettsia felis was first recognised two decades ago and has now been described as endemic to all continents except Antarctica. The rickettsiosis caused by R. felis is known as flea-borne spotted fever or cat-flea typhus. The large number of arthropod species found to harbour R. felis, and be potential vectors, supports the view that it is a pan-global microbe. The main arthropod reservoir and vector is the cat flea, Ctenocephalides felis, yet a further twenty other species of fleas, ticks a...

  7. Detección de Rickettsia spp. en Suero y Garrapatas de Mamíferos Silvestres en Cautiverio en Montería, Córdoba -resumen-

    Dave Wehdeking-Hernández

    2014-12-01

    Full Text Available Las rickettsiosis transmitidas por garrapatas son causadas por bacterias intracelulares pertenecientes al grupo de las fiebres manchadas del género Rickettsia. Estas zoonosis son algunas de las enfermedades transmitidas por vectores de más antiguo conocimiento‚ e incluyen dentro de su ciclo de transmisión diversas especies de mamíferos. No obstante‚ en Colombia existen pocos trabajos enfocados a conocer la dinámica de las rickettsiosis en animales silvestres. El objetivo de este estudio fue detectar‚ por medio de la técnica de PCR en tiempo real‚ la presencia de Rickettsia spp.‚ en muestras de suero y garrapatas colectadas en mamíferos mantenidos en cautiverio en el Centro de Atención y Valoración de Fauna Silvestre de la Corporación autónoma Regional de los Valles del Sinú y San Jorge CAV-CVS‚ entre los años 2009 y 2014. Se obtuvieron muestras de sangre de 14 felinos‚ de las especies Leopardus pardalis (10‚ Puma concolor (3 y Panthera onca (1; de 58 primates‚ correspondientes a las especies Ateles geofroyii (17‚ Alouatta seniculus (14‚ Cebus capucinus (14‚ Saguinus oedipus (6‚ Cebus albifrons (4 Aotus sp. (2 y Ateles belzebuth (1; y de otros mamíferos: Tayassu pecari (1‚ Procyon cancrivorous (1 y Cerdocyon thous (1. En cuanto a las garrapatas‚ se colectaron e identificaron individuos del género Haemaphysalis sp. en un ejemplar de Sylvilagus sp.‚ y de las especies Amblyomma ovale‚ Riphicephalus microplus y Dermacentor nitens en P. concolor. Posteriormente fueron organizadas en pool. No se encontraron muestras de suero positivas a Rickettsia spp. (0/72. Se detectó un pool de garrapatas de la especie A. ovale positivo a este microorganismo. Este es el primer reporte en Colombia de ectoparásitos de Puma concolor positivos a Rickettsia spp. Se requiere continuar con los muestreos de ectoparásitos para determinar si este microorganismo se encuentra circulante entre mamíferos silvestres en el país.

  8. Comparative growth of spotted fever group Rickettsia spp. strains in Vero cells

    Silva, Arannadia Barbosa; Duarte, Myrian Morato; Vizzoni, Vinicius Figueiredo; Duré, Ana Íris de Lima; Lopéz, Diego Montenegro; Nogueira, Rita de Maria Seabra; Soares, Carlos Augusto Gomes; Machado-Ferreira, Erik; Gazêta, Gilberto Salles

    2016-01-01

    In Brazil, the spotted fever group (SFG) Rickettsia rickettsii and Rickettsia parkeri related species are the etiological agents of spotted fever rickettsiosis. However, the SFG, Rickettsia rhipicephali, that infects humans, has never been reported. The study of growth dynamics can be useful for understanding the infective and invasive capacity of these pathogens. Here, the growth rates of the Brazilian isolates R. rickettsii str. Taiaçu, R. parkeri str. At#24, and R. rhipicephali HJ#5, were evaluated in Vero cells by quantitative polymerase chain reaction. R. rhipicephali showed different kinetic growth compared to R. rickettsii and R. parkeri. PMID:27508322

  9. Molecular detection and groEL typing of Rickettsia aeschlimannii in Sardinian ticks.

    Chisu, Valentina; Zobba, Rosanna; Foxi, Cipriano; Pisu, Danilo; Masala, Giovanna; Alberti, Alberto

    2016-09-01

    Rickettsia aeschlimannii is an emerging tick-borne pathogen of the spotted fever group Rickettsiae with considerable impact on both human and animal health. This study reports the molecular detection and groEL characterization of R. aeschlimannii in ticks collected from birds and ruminants in a typical Mediterranean environment. Phylogeny of R. aeschlimannii and species representative of the spotted fever and typhus groups based on the groEL gene is reconstructed for the first time. Results expand the knowledge on distribution and typing of emerging human tick-borne diseases in Sardinia and pave the way for future molecular epidemiology studies of zoonotic Rickettsiae. PMID:27130322

  10. Sequencing and comparison of the Rickettsia genomes from the whitefly Bemisia tabaci Middle East Asia Minor I.

    Zhu, Dan-Tong; Xia, Wen-Qiang; Rao, Qiong; Liu, Shu-Sheng; Ghanim, Murad; Wang, Xiao-Wei

    2016-08-01

    The whitefly, Bemisia tabaci, harbors the primary symbiont 'Candidatus Portiera aleyrodidarum' and a variety of secondary symbionts. Among these secondary symbionts, Rickettsia is the only one that can be detected both inside and outside the bacteriomes. Infection with Rickettsia has been reported to influence several aspects of the whitefly biology, such as fitness, sex ratio, virus transmission and resistance to pesticides. However, mechanisms underlying these differences remain unclear, largely due to the lack of genomic information of Rickettsia. In this study, we sequenced the genome of two Rickettsia strains isolated from the Middle East Asia Minor 1 (MEAM1) species of the B. tabaci complex in China and Israel. Both Rickettsia genomes were of high coding density and AT-rich, containing more than 1000 coding sequences, much larger than that of the coexisted primary symbiont, Portiera. Moreover, the two Rickettsia strains isolated from China and Israel shared most of the genes with 100% identity and only nine genes showed sequence differences. The phylogenetic analysis using orthologs shared in the genus, inferred the proximity of Rickettsia in MEAM1 and Rickettsia bellii. Functional analysis revealed that Rickettsia was unable to synthesize amino acids required for complementing the whitefly nutrition. Besides, a type IV secretion system and a number of virulence-related genes were detected in the Rickettsia genome. The presence of virulence-related genes might benefit the symbiotic life of the bacteria, and hint on potential effects of Rickettsia on whiteflies. The genome sequences of Rickettsia provided a basis for further understanding the function of Rickettsia in whiteflies. PMID:27273750

  11. Detección de Rickettsia spp. en Garrapatas de Myrmecophaga tridactyla de Vida Libre en la Sabana Inundable de Casanare‚ Colombia -resumen-

    César Rojano-Bolaño

    2014-12-01

    Full Text Available Las bacterias del género Rickettsia son organismos con distribución mundial‚ causantes de algunas enfermedades zoonóticas de gran importancia en salud pública. Sin embargo‚ en Colombia son pocos los estudios enfocados a conocer su distribución y los vectores involucrados. El objetivo de este estudio fue detectar la presencia de Rickettsia spp.‚ en garrapatas colectadas en nueve osos palmeros (Myrmecophaga tridactyla de vida libre en el municipio de Pore‚ Casanare‚ entre los años 2013 y 2014. Los osos palmeros fueron capturados con el método de búsqueda activa‚ para posteriormente ser anestesiados utilizando un dardo con una combinación anestésica consistente en Ketamina 12 mg/kg y Xilacina 0‚5 mg/kg por vía intramuscular. Las garrapatas fueron colectadas directamente de los individuos‚ con ayuda de pinzas. En total se obtuvieron 204 ectoparásitos‚ que fueron almacenados en alcohol al 70%‚ y posteriormente fueron identificados como pertenecientes a la especie Amblyomma cajennense. Las garrapatas se organizaron en 68 pool de tres individuos y fueron analizadas por medio de la técnica de PCR en tiempo real. Se detectaron 12 pool de garrapatas positivos a este microorganismo (17‚6%. Los resultados preliminares de este estudio muestran que Rickettsia spp.‚ bacteria intracelular importante en salud pública‚ se encuentra circulante entre ectoparásitos de animales silvestres en la sabana inundable del municipio de Pore‚ Casanare. Dado que diversos estudios han reportado que los rickettsiales tienen una mayor incidencia en ambientes húmedos‚ se recomienda continuar con los estudios en mamíferos silvestres y sus garrapatas en la sabana natural inundable.

  12. Orientia, rickettsia, and leptospira pathogens as causes of CNS infections in Laos

    Dittrich, Sabine; Rattanavong, Sayaphet; Lee, Sue J;

    2015-01-01

    BACKGROUND: Scrub typhus (caused by Orientia tsutsugamushi), murine typhus (caused by Rickettsia typhi), and leptospirosis are common causes of febrile illness in Asia; meningitis and meningoencephalitis are severe complications. However, scarce data exist for the burden of these pathogens in...

  13. Draft Genome Sequence of Rickettsia aeschlimannii, Associated with Hyalomma marginatum Ticks

    Sentausa, Erwin; El Karkouri, Khalid; Michelle, Caroline; Raoult, Didier; Fournier, Pierre-Edouard

    2014-01-01

    Rickettsia aeschlimannii is a tick-associated human pathogen. We report here the draft genome of R. aeschlimannii strain MC16, isolated from Hyalomma marginatum marginatum ticks collected in Morocco.

  14. Spotted fever group rickettsiae in ticks collected from wild animals in Israel.

    Keysary, Avi; Eremeeva, Marina E; Leitner, Moshe; Din, Adi Beth; Wikswo, Mary E; Mumcuoglu, Kosta Y; Inbar, Moshe; Wallach, Arian D; Shanas, Uri; King, Roni; Waner, Trevor

    2011-11-01

    We report molecular evidence for the presence of spotted fever group rickettsiae (SFGR) in ticks collected from roe deer, addax, red foxes, and wild boars in Israel. Rickettsia aeschlimannii was detected in Hyalomma marginatum and Hyalomma detritum while Rickettsia massiliae was present in Rhipicephalus turanicus ticks. Furthermore, a novel uncultured SFGR was detected in Haemaphysalis adleri and Haemaphysalis parva ticks from golden jackals. The pathogenicity of the novel SFGR for humans is unknown; however, the presence of multiple SFGR agents should be considered when serological surveillance data from Israel are interpreted because of significant antigenic cross-reactivity among Rickettsia. The epidemiology and ecology of SFGR in Israel appear to be more complicated than was previously believed. PMID:22049050

  15. Isolation of Rickettsia felis in the Mosquito Cell Line C6/36

    Horta, Maurício C.; Labruna, Marcelo B.; Edison L. Durigon; Teresinha T.S. Schumaker

    2006-01-01

    We report the isolation and establishment of Rickettsia felis in the C6/36 cell line. Rickettsial growth was intense, always with 90 to 100% of cells being infected after few weeks. The rickettsial isolate was confirmed by testing infected cells by PCR and sequencing fragments of three major Rickettsia genes (gltA, ompB, and the 17-kDa protein gene).

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

    Qi, Yong; Xiong, Xiaolu; Wang, Xile; Duan, Changsong; Jia, Yinjun; Jiao, Jun; Gong, Wenping; Wen, Bohai

    2013-01-01

    Background Rickettsia heilongjiangensis, the agent of Far-Eastern spotted fever (FESF), is an obligate intracellular bacterium. The surface-exposed proteins (SEPs) of rickettsiae are involved in rickettsial adherence to and invasion of host cells, intracellular bacterial growth, and/or interaction with immune cells. They are also potential molecular candidates for the development of diagnostic reagents and vaccines against rickettsiosis. Methods R. heilongjiangensis SEPs were identified by bi...

  17. Identification of Novel Surface-Exposed Proteins of Rickettsia rickettsii by Affinity Purification and Proteomics

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

    2014-01-01

    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...

  18. Analysis of T-cell-dependent and -independent antigens of Rickettsia conorii with monoclonal antibodies.

    Feng, H M; Walker, D H; Wang, J. G.

    1987-01-01

    Four monoclonal antibodies from euthymic mice and two monoclonal antibodies from athymic mice were directed against antigens of Rickettsia conorii, as shown by both indirect immunofluorescence and an enzyme immunoassay. There was extensive cross-reactivity with other spotted fever group rickettsiae. Euthymic monoclonal antibodies 3-2 and 9-2 (immunoglobulin G2a [IgG2a]) and 27-10 (IgG1) distinctly outlined the acetone-fixed rickettsial surface, as determined by indirect immunofluorescence; on...

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

    Svendsen, Claus Bo; Boye, Mette; Struve, Carsten;

    2009-01-01

    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 bact......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...

  20. Detection of Rickettsia rickettsii antibodies in human sera by crossed immunoelectrophoresis.

    Anacker, R. L.; Philip, R N; Wilfert, C M; Kleeman, K T; Turner, L; MacCormack, J. N.; Hechemy, K E

    1983-01-01

    To identify Rickettsia rickettsii antigens of immunological importance, we examined sera from patients with serologically confirmed cases of Rocky Mountain spotted fever by crossed immunoelectrophoresis for antibodies to antigens extracted from the R strain of R. rickettsii with the detergent Triton X-100. Sixteen antigens were identified in the detergent extract by crossed immunoelectrophoresis with a hyperimmune rabbit serum raised against whole rickettsiae. When the rabbit antiserum was pl...

  1. Rickettsia felis, an emerging flea-transmitted human pathogen

    Stephen Graves

    2011-07-01

    Full Text Available Rickettsia felis was first recognised two decades ago and has now been described as endemic to all continents except Antarctica. The rickettsiosis caused by R. felis is known as flea-borne spotted fever or cat-flea typhus. The large number of arthropod species found to harbour R. felis and that may act as potential vectors support the view that it is a pan-global microbe. The main arthropod reservoir and vector is the cat flea, Ctenocephalides felis, yet more than 20 other species of fleas, ticks, and mites species have been reported to harbour R. felis. Few bacterial pathogens of humans have been found associated with such a diverse range of invertebrates. With the projected increase in global temperature over the next century, there is concern that changes to the ecology and distribution of R. felis vectors may adversely impact public health.

  2. Rickettsia retinitis cases in India: a few comments.

    Tripathy, Koushik; Chawla, Rohan; Sharma, Yog Raj; Vohra, Rajpal

    2016-12-01

    An important cause of infectious retinitis, not well-described in Indian literature, has been analyzed in detail systematically by Kawali A. and colleagues. However, Rickettsia retinitis (RR) was diagnosed at titres of 1:160 by the Weil-Felix test (WFT). The sensitivity and specificity of WFT at this level are poor compared to the gold standard immunofluorescent antibody assay. However, we understand that financial constraints of the Indian patients limit the availability of more definite tests. In our opinion, the optical coherence tomography features of RR described by the authors may be mimicked by other causes of retinitis, such as toxoplasma retinitis or even cotton wool spots. Infectious retinitis including RR should be treated by an antimicrobial agent with or without oral steroids until larger series or randomized controlled trials prove otherwise. PMID:26920002

  3. Conditional fitness benefits of the Rickettsia bacterial symbiont in an insect pest.

    Cass, Bodil N; Himler, Anna G; Bondy, Elizabeth C; Bergen, Jacquelyn E; Fung, Sierra K; Kelly, Suzanne E; Hunter, Martha S

    2016-01-01

    Inherited bacterial symbionts are common in arthropods and can have strong effects on the biology of their hosts. These effects are often mediated by host ecology. The Rickettsia symbiont can provide strong fitness benefits to its insect host, Bemisia tabaci, under laboratory and field conditions. However, the frequency of the symbiont is heterogeneous among field collection sites across the USA, suggesting that the benefits of the symbiont are contingent on additional factors. In two whitefly genetic lines collected from the same location, we tested the effect of Rickettsia on whitefly survival after heat shock, on whitefly competitiveness at different temperatures, and on whitefly competitiveness at different starting frequencies of Rickettsia. Rickettsia did not provide protection against heat shock nor affect the competitiveness of whiteflies at different temperatures or starting frequencies. However, there was a strong interaction between Rickettsia infection and whitefly genetic line. Performance measures indicated that Rickettsia was associated with significant female bias in both whitefly genetic lines, but in the second whitefly genetic line it conferred no significant fitness benefits nor conferred any competitive advantage to its host over uninfected whiteflies in population cages. These results help to explain other reports of variation in the phenotype of the symbiosis. Furthermore, they demonstrate the complex nature of these close symbiotic associations and the need to consider these interactions in the context of host population structure. PMID:26376661

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

    2006-05-01

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

  5. Identification and Characterization of Novel Small RNAs in Rickettsia prowazekii

    Schroeder, Casey L. C.; Narra, Hema P.; Sahni, Abha; Rojas, Mark; Khanipov, Kamil; Patel, Jignesh; Shah, Riya; Fofanov, Yuriy; Sahni, Sanjeev K.

    2016-01-01

    Emerging evidence implicates a critically important role for bacterial small RNAs (sRNAs) as post-transcriptional regulators of physiology, metabolism, stress/adaptive responses, and virulence, but the roles of sRNAs in pathogenic Rickettsia species remain poorly understood. Here, we report on the identification of both novel and well-known bacterial sRNAs in Rickettsia prowazekii, known to cause epidemic typhus in humans. RNA sequencing of human microvascular endothelial cells (HMECs), the preferred targets during human rickettsioses, infected with R. prowazekii revealed the presence of 35 trans-acting and 23 cis-acting sRNAs, respectively. Of these, expression of two trans-acting (Rp_sR17 and Rp_sR60) and one cis-acting (Rp_sR47) novel sRNAs and four well-characterized bacterial sRNAs (RNaseP_bact_a, α-tmRNA, 4.5S RNA, 6S RNA) was further confirmed by Northern blot or RT-PCR analyses. The transcriptional start sites of five novel rickettsial sRNAs and 6S RNA were next determined using 5′ RLM-RACE yielding evidence for their independent biogenesis in R. prowazekii. Finally, computational approaches were employed to determine the secondary structures and potential mRNA targets of novel sRNAs. Together, these results establish the presence and expression of sRNAs in R. prowazekii during host cell infection and suggest potential functional roles for these important post-transcriptional regulators in rickettsial biology and pathogenesis. PMID:27375581

  6. Detection of antibodies anti-Rickettsia spp. in dogs and horses in the state of Mato Grosso, Brazil

    Marcus Vinicius de Amorim

    2014-02-01

    Full Text Available This study evaluated the infection caused by Rickettsia spp. among dogs and horses from Mato Grosso State. A total of 384 dogs and 460 horses were tested by the Indirect Immunofluorescence Assay (IFA for Rickettsia rickettsii, Rickettsia parkeri, Rickettsia amblyommii, Rickettsia rhipicephali and Rickettsia bellii Overall, 3.12% (12/384 of the dogs were seroreactive for at least one Rickettsia species. A total of 7 (1.82% canine sera showed titers to R. bellii at least 4-fold higher than those to any of the other rickettsial antigens, allowing us to consider that these dogs were infected by R. bellii. In horses, 273 (59.34 % samples were positives for at least one antigen tested, and highest anti-Rickettsia spp. endpoint titers were observed for R. amblyommii, suggesting homologous reactions to this agent or a very closely related organism. The results showed that dogs are under low exposition to ticks infected with spotted fever group Rickettsia, indicating low risk of human infection by these agents. However, R. amblyommii is widely distributed in the State.

  7. Thoracic radiographic findings in dogs infected with Rickettsia rickettsii

    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

  8. Evidencia serológica de la presencia de Rickettsias del grupo de la fiebre manchada en la Amazonía del Perú

    Moisés Sihuincha M

    2006-10-01

    Full Text Available Con el objetivo de demostrar la existencia de transmisión de Rickettsias del grupo de la fiebre manchada en la Amazonía peruana, se tomaron muestras de sangre a pacientes febriles agudos en establecimientos de salud de la ciudad de Iquitos, la ciudad más poblada de la Amazonía del Perú. Las muestras fueron procesadas mediante inmunofluorescencia indirecta para medir anticuerpos totales e IgG específica para el grupo de fiebre de las manchadas. Entre enero y julio de 2006, se obtuvieron muestras de 250 pacientes. El 37% de las muestras tuvieron títulos positivos de IgG, demostrando así haber tenido contacto con el agente, de ellas, nueve fueron clasificadas como casos agudos, en los que se descartó otras infecciones endémicas como dengue, malaria y leptospirosis. Los casos presentaron una enfermedad febril acompañada de síntomas como tos, sarpullido y hemoptisis. Cuatro casos fueron hospitalizados, dos fueron graves y uno de ellos falleció. En conclusión, existe evidencia serológica de la circulación de Rickettsias del grupo de las fiebre manchada en la Amazonía peruana, por su frecuencia y potencial gravedad debería ser tomada en cuenta como diagnóstico diferencial del síndrome febril agudo en esta región.

  9. The Rickettsia Endosymbiont of Ixodes pacificus Contains All the Genes of De Novo Folate Biosynthesis.

    Daniel J Hunter

    Full Text Available Ticks and other arthropods often are hosts to nutrient providing bacterial endosymbionts, which contribute to their host's fitness by supplying nutrients such as vitamins and amino acids. It has been detected, in our lab, that Ixodes pacificus is host to Rickettsia species phylotype G021. This endosymbiont is predominantly present, and 100% maternally transmitted in I. pacificus. To study roles of phylotype G021 in I. pacificus, bioinformatic and molecular approaches were carried out. MUMmer genome alignments of whole genome sequence of I. scapularis, a close relative to I. pacificus, against completely sequenced genomes of R. bellii OSU85-389, R. conorii, and R. felis, identified 8,190 unique sequences that are homologous to Rickettsia sequences in the NCBI Trace Archive. MetaCyc metabolic reconstructions revealed that all folate gene orthologues (folA, folC, folE, folKP, ptpS required for de novo folate biosynthesis are present in the genome of Rickettsia buchneri in I. scapularis. To examine the metabolic capability of phylotype G021 in I. pacificus, genes of the folate biosynthesis pathway of the bacterium were PCR amplified using degenerate primers. BLAST searches identified that nucleotide sequences of the folA, folC, folE, folKP, and ptpS genes possess 98.6%, 98.8%, 98.9%, 98.5% and 99.0% identity respectively to the corresponding genes of Rickettsia buchneri. Phylogenetic tree constructions show that the folate genes of phylotype G021 and homologous genes from various Rickettsia species are monophyletic. This study has shown that all folate genes exist in the genome of Rickettsia species phylotype G021 and that this bacterium has the genetic capability for de novo folate synthesis.

  10. Amblyomma maculatum Feeding Augments Rickettsia parkeri Infection in a Rhesus Macaque Model: A Pilot Study.

    Banajee, Kaikhushroo H; Embers, Monica E; Langohr, Ingeborg M; Doyle, Lara A; Hasenkampf, Nicole R; Macaluso, Kevin R

    2015-01-01

    Rickettsia parkeri is an emerging eschar-causing human pathogen in the spotted fever group of Rickettsia and is transmitted by the Gulf coast tick, Amblyomma maculatum. Tick saliva has been shown to alter both the cellular and humoral components of the innate and adaptive immune systems. However, the effect of this immunomodulation on Rickettsia transmission and pathology in an immunocompetent vertebrate host has not been fully examined. We hypothesize that, by modifying the host immune response, tick feeding enhances infection and pathology of pathogenic spotted fever group Rickettsia sp. In order to assess this interaction in vivo, a pilot study was conducted using five rhesus macaques that were divided into three groups. One group was intradermally inoculated with low passage R. parkeri (Portsmouth strain) alone (n = 2) and another group was inoculated during infestation by adult, R. parkeri-free A. maculatum (n = 2). The final macaque was infested with ticks alone (tick feeding control group). Blood, lymph node and skin biopsies were collected at several time points post-inoculation/infestation to assess pathology and quantify rickettsial DNA. As opposed to the tick-only animal, all Rickettsia-inoculated macaques developed inflammatory leukograms, elevated C-reactive protein concentrations, and elevated TH1 (interferon-γ, interleukin-15) and acute phase inflammatory cytokines (interleukin-6) post-inoculation, with greater neutrophilia and interleukin-6 concentrations in the tick plus R. parkeri group. While eschars formed at all R. parkeri inoculation sites, larger and slower healing eschars were observed in the tick feeding plus R. parkeri group. Furthermore, dissemination of R. parkeri to draining lymph nodes early in infection and increased persistence at the inoculation site were observed in the tick plus R. parkeri group. This study indicates that rhesus macaques can be used to model R. parkeri rickettsiosis, and suggests that immunomodulatory factors

  11. RickA expression is not sufficient to promote actin-based motility of Rickettsia raoultii.

    Premanand Balraj

    Full Text Available BACKGROUND: Rickettsia raoultii is a novel Rickettsia species recently isolated from Dermacentor ticks and classified within the spotted fever group (SFG. The inability of R. raoultii to spread within L929 cells suggests that this bacterium is unable to polymerize host cell actin, a property exhibited by all SFG rickettsiae except R. peacocki. This result led us to investigate if RickA, the protein thought to generate actin nucleation, was expressed within this rickettsia species. METHODOLOGY/PRINCIPAL FINDINGS: Amplification and sequencing of R. raoultii rickA showed that this gene encoded a putative 565 amino acid protein highly homologous to those found in other rickettsiae. Using immunofluorescence assays, we determined that the motility pattern (i.e. microcolonies or cell-to-cell spreading of R. raoultii was different depending on the host cell line in which the bacteria replicated. In contrast, under the same experimental conditions, R. conorii shares the same phenotype both in L929 and in Vero cells. Transmission electron microscopy analysis of infected cells showed that non-motile bacteria were free in the cytosol instead of enclosed in a vacuole. Moreover, western-blot analysis demonstrated that the defect of R. raoultii actin-based motility within L929 cells was not related to lower expression of RickA. CONCLUSION/SIGNIFICANCE: These results, together with previously published data about R. typhi, strongly suggest that another factor, apart from RickA, may be involved with be responsible for actin-based motility in bacteria from the Rickettsia genus.

  12. Molecular Investigations of Rickettsia helvetica Infection in Dogs, Foxes, Humans, and Ixodes Ticks▿

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

    2009-01-01

    Rickettsia helvetica, a tick-borne member of the spotted-fever-group rickettsiae, is a suspected pathogen in humans; however, its role in animals is unknown. The aims of this study were to establish a R. helvetica-specific real-time TaqMan PCR assay and apply it to the analysis of tick vectors (to determine potential exposure risk) and blood samples from Canidae and humans (to determine prevalence of infection). The newly designed 23S rRNA gene assay for R. helvetica was more sensitive than a...

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

    Rees Robert L

    2011-10-01

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

  14. 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

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

    2010-01-01

    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 i...

  15. 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

    I. Amat

    2003-12-01

    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

  16. Rickettsia sp. strain colombianensi (Rickettsiales: Rickettsiaceae): a new proposed Rickettsia detected in Amblyomma dissimile (Acari: Ixodidae) from iguanas and free-living larvae ticks from vegetation.

    Miranda, Jorge; Portillo, Aránzazu; Oteo, José A; Mattar, Salim

    2012-07-01

    From January to December 2009, 55 Amblyomma dissimile (Koch) ticks removed from iguanas in the municipality of Monteria and 3,114 ticks [458 Amblyomma sp. larvae, 2,636 Rhipicephalus microplus (Canestrini) larvae and 20 Amblyomma sp. nymphs] collected over vegetation in Los Cordobas were included in the study. The ticks were pooled into groups from which DNA was extracted. For initial screening of Rickettsia sp., each pool was analyzed by gltA real-time polymerase chain reaction (PCR). Positive pools were further studied using gltA, ompA, and ompB conventional PCR assays. Sequencing and phylogenetic analysis were also conducted. Rickettsial DNA was found in 28 pools of ticks (16 A. dissimile pools and 12 free-living larvae pools) out of 113 (24.7%) using real-time PCR. The same 28 pools were also positive using conventional PCR assays aimed to amplify gltA, ompA, and ompB. For each gene analyzed, PCR products obtained from 4/28 pools (two pools of A. dissimile, one pool of Amblyomma sp. larvae and one pool of Rh. microplus larvae) were randomly chosen and sequenced twice. Nucleotide sequences generated were identical to each other for each of the rickettsial genes gltA, ompA, and ompB, and showed 99.4, 95.6, and 96.4% identity with those of Rickettsia tamurae. They were deposited in the GenBank database under accession numbers JF905456, JF905458, and JF905457, respectively. In conclusion, we present the first molecular evidence of a novel Rickettsia (Rickettsia sp. strain Colombianensi) infecting A. dissimile ticks collected from iguanas, and also Rh. microplus and unspeciated Amblyomma larvae from vegetation in Colombia. PMID:22897060

  17. Seroepidemiological survey of Rickettsia spp. in dogs from the endemic area of Rickettsia parkeri rickettsiosis in Uruguay.

    Lado, Paula; Costa, Francisco B; Verdes, José M; Labruna, Marcelo B; Venzal, José M

    2015-06-01

    Rickettsia parkeri rickettsiosis is a vector-borne zoonosis that occurs in some countries of the American continent. Following the first description and determination of the pathogenicity to humans in 2004 in USA, this bacterium has been reported in several South American countries. Human cases have been diagnosed in both Uruguay and Argentina in the past years. This study consisted in a serosurvey of 1000 domestic dogs living in the endemic area of rickettsiosis in Uruguay, where Amblyomma triste is the tick vector. Sera were analyzed by Indirect Immunofluorescence Assay (IFA), against antigens of three different rickettsial species: R. rhipicephali, R. felis and R. parkeri. It was determined that 20.3% of the dogs had antibodies that reacted to at least one of the three species tested, taking as cut off ≥64 titers. Furthermore, 140 of the seropositive dogs (14%) had a titer at least 4 times higher to R. parkeri than those of any of the other species, thus, it was considered that the immune response was stimulated by that species in particular. This is the first serological survey in primary hosts for adults of A. triste in Uruguay, and therefore the first prevalence values are reported. Adult A. triste ticks collected from the environment as well as from dogs were analyzed by PCR in order to confirm the current circulation of the agent in the area. In this matter, two out of 28 ticks from dogs, and 3 out of 53 ticks from the environment were positive, and the corresponding sequence analysis revealed 100% similarity with R. parkeri strain maculatum. PMID:25735816

  18. Draft Genome Sequence of Rickettsia sp. Strain MEAM1, Isolated from the Whitefly Bemisia tabaci

    Rao, Qiong; Wang, Shuang; Zhu, Dan-Tong; Wang, Xiao-Wei; Liu, Shu-Sheng

    2012-01-01

    We report the draft genome sequence of the Rickettsia sp. strain MEAM1, which is a facultative symbiont from an invasive species of the whitefly Bemisia tabaci. The total length of the assembled genome is approximately 1.24 Mb, with 335 scaffolds and 1,247 coding sequences predicted within the genome.

  19. Draft Genome Sequence of a New Zealand Rickettsia-Like Organism Isolated from Farmed Chinook Salmon

    Draper, Jenny; Brosnahan, Cara L.; Orr, Della; McFadden, Andrew; Jones, Brian

    2016-01-01

    We report here the draft genome sequence of a rickettsia-like organism, isolated from a New Zealand Chinook salmon farm experiencing high mortality. The genome is approximately 3 Mb in size, has a G+C content of approximately 39.2%, and is predicted to contain 2,870 coding sequences. PMID:27365345

  20. Detection and identification of Anaplasma phagocytophilum, Borrelia burgdorferi, and Rickettsia helvetica in Danish Ixodes ricinus ticks

    Skarphédinsson, Sigurdur; Lyholm, Birgitte Fjendbo; Ljungberg, Marianne;

    2007-01-01

    % 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...

  1. Molecular detection of Rickettsia species in Amblyomma ticks collected from snakes in Thailand

    Sumrandee, C.; Hirunkanokpun, S.; Doornbos, K.; Kitthawee, S.; Baimai, V.; Grubhoffer, Libor; Trinachartvanit, W.; Ahantarig, A.

    2014-01-01

    Roč. 5, č. 6 (2014), s. 632-640. ISSN 1877-959X Institutional support: RVO:60077344 Keywords : Tick * Rickettsia spp. * Amblyomma varanense * Amblyomma helvolum * Snake * Thailand Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.718, year: 2014

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

    Ogrzewalska, M.; Literák, I.; Cárdenas-Callirgos, J. M.; Čapek, Miroslav; Labruna, M. B.

    2012-01-01

    Roč. 3, č. 4 (2012), s. 254-256. ISSN 1877-959X R&D Projects: GA AV ČR IAA601690901; GA MŠk LC06073 Institutional support: RVO:68081766 Keywords : Rickettsia bellii * ticks * Amblyomma calcaratum * birds * Peru Subject RIV: EG - Zoology Impact factor: 2.353, year: 2012

  3. Detection of flea-borne Rickettsia species in the Western Himalayan region of India

    R Chahota

    2015-01-01

    Full Text Available Human infections by various rickettsial species are frequently reported globally. We investigated a flea-borne rickettsial outbreak infecting 300 people in Western Himalayan region of India. Arthropod vectors (ticks and fleas and animal and human blood samples from affected households were analysed by gltA and ompB genes based polymerase chain reaction (PCR. Rat flea (Ceratophyllus fasciatus samples were found harbouring a Rickettsia sp. Phylogenetic analysis based on gltA gene using PHYLIP revealed that the detected Rickettsia sp. has 100% identity with SE313 and RF2125 strains of Rickettsia sp. of flea origin from Egypt and Thai-Myanmar border, respectively and cf1 and 5 strains from fleas and lice from the USA. But, the nucleotide sequence of genetically variable gene ompB of R14 strain was found closely related to cf9 strain, reported from Ctenocephalides felis fleas. These results highlight the public health importance of such newly discovered or less recognised Rickettsia species/strains, harboured by arthropod vectors like fleas.

  4. Bacteria of the genus Rickettsia in ticks (Acari: Ixodidae) collected from birds in Costa Rica

    Ogrzewalska, M.; Literák, I.; Čapek, Miroslav; Sychra, O.; Calderón, V. Á.; Rodríguez, B. C.; Prudencio, C.; Martins, T. F.; Labruna, M. B.

    2015-01-01

    Roč. 6, č. 4 (2015), s. 478-482. ISSN 1877-959X R&D Projects: GA AV ČR IAA601690901 Institutional support: RVO:68081766 Keywords : Rickettsia * Ticks * Birds * Ixodes * Amblyomma * Costa Rica Subject RIV: EG - Zoology Impact factor: 2.718, year: 2014

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

    Richard Campos Pacheco

    2009-06-01

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

  6. 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

    Celso Eduardo de Souza

    2008-09-01

    Full Text Available Diseases transmitted by ticks have been an important health problem all over the world. Brazilian Spotted Fever (BSF stands for a serious epidemiological concern due to the high mortality rates pointed out. Capybaras are commonly incriminated as possible reservoirs in the BSF transmission cycle. In the last decades the numbers of these animals raised sharply and they have invaded human areas. They intensify the contact between ticks and humans beings. This study aim is to contribute to the possible role performed for this rodent in the BSF epidemiology in some areas located in Campinas region, São Paulo. Cabybaras infected by rickettsiae of BSF group were studied through the analysis of the frequencies of BSF-group rickettisae antibodies titer = 64 by indirect immunofluorescence test (IFA, and data from human cases epidemiological surveillance. The serum frequency positiveness varied greatly according to areas where animals were captured. However it was found serum positiviness only in the areas where human cases of BSF were reported. These findings suggest the capybara may be seen as sentinel animal. Due to presence of serological cross reactivity between microorganisms belonging to SF group, the results must be interpreted carefully and additional methods to distinguish pathogenic rickettsiae are required in our country.Doenças transmitidas por carrapatos vêm sendo um importante problema de saúde pública no mundo. A Febre Maculosa Brasileira (FMB representa um sério risco epidemiológico devido às altas taxas de letalidade apresentadas. As capivaras são freqüentemente incriminadas como possíveis reservatórios no ciclo de transmissão da FMB. Nas últimas décadas o número desses animais cresceu intensamente e eles invadiram os espaços humanos. As capivaras intensificam o contato entre carrapatos e seres humanos na medida em que se apresentam muito infestadas por estes parasitos. O objetivo deste estudo é contribuir para o

  7. Detection of Borrelia burgdorferi sensu lato and spotted fever group rickettsiae in hard ticks (Acari, Ixodidae) parasitizing bats in Poland

    Piksa, Krzysztof; Stańczak, Joanna; Biernat, Beata; Górz, Andrzej; Nowak-Chmura, Magdalena; Siuda, Krzysztof

    2016-01-01

    A total of 491 Ixodes vespertilionis and 8 Ixodes ricinus collected from bats and cave walls in southern Poland between 2010 and 2012 were examined by the polymerase chain reaction for tick-transmitted pathogens. PCR analysis for Borrelia burgdorferi s.l., Rickettsia spp., and Anaplasma phagocytophilum yielded negative results for all I. vespertilionis. DNA of Rickettsia helvetica was detected in three specimens of I. ricinus attached to Rhinolophus hipposideros or Myotis myotis, while Borrel...

  8. An anomalous type IV secretion system in Rickettsia is evolutionarily conserved.

    Joseph J Gillespie

    Full Text Available BACKGROUND: Bacterial type IV secretion systems (T4SSs comprise a diverse transporter family functioning in conjugation, competence, and effector molecule (DNA and/or protein translocation. Thirteen genome sequences from Rickettsia, obligate intracellular symbionts/pathogens of a wide range of eukaryotes, have revealed a reduced T4SS relative to the Agrobacterium tumefaciens archetype (vir. However, the Rickettsia T4SS has not been functionally characterized for its role in symbiosis/virulence, and none of its substrates are known. RESULTS: Superimposition of T4SS structural/functional information over previously identified Rickettsia components implicate a functional Rickettsia T4SS. virB4, virB8 and virB9 are duplicated, yet only one copy of each has the conserved features of similar genes in other T4SSs. An extraordinarily duplicated VirB6 gene encodes five hydrophobic proteins conserved only in a short region known to be involved in DNA transfer in A. tumefaciens. virB1, virB2 and virB7 are newly identified, revealing a Rickettsia T4SS lacking only virB5 relative to the vir archetype. Phylogeny estimation suggests vertical inheritance of all components, despite gene rearrangements into an archipelago of five islets. Similarities of Rickettsia VirB7/VirB9 to ComB7/ComB9 proteins of epsilon-proteobacteria, as well as phylogenetic affinities to the Legionella lvh T4SS, imply the Rickettsiales ancestor acquired a vir-like locus from distantly related bacteria, perhaps while residing in a protozoan host. Modern modifications of these systems likely reflect diversification with various eukaryotic host cells. CONCLUSION: We present the rvh (Rickettsiales vir homolog T4SS, an evolutionary conserved transporter with an unknown role in rickettsial biology. This work lays the foundation for future laboratory characterization of this system, and also identifies the Legionella lvh T4SS as a suitable genetic model.

  9. Isolation by a sensitive centrifugation cell culture system of 52 strains of spotted fever group rickettsiae from ticks collected in France.

    Péter, O; Raoult, D.; Gilot, B.

    1990-01-01

    Boutonneuse fever caused by Rickettsia conorii is transmitted mainly by the brown dog tick, Rhipicephalus sanguineus. We collected 540 ticks in Marseille, France, and tried to isolate as many strains of rickettsia as possible. Ticks were evaluated for the presence of rickettsia by the hemolymph test and by a new culture system, the centrifugation-shell vial technique. We avoided contamination in the culture system. Prior to ticks being submitted to the hemolymph test, they were disinfected. O...

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

    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

    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

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

    ROZENTAL Tatiana

    2002-01-01

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

  12. Tests on ticks from wild birds collected in the eastern United States for rickettsiae and viruses

    Clifford, C.M.; Sonenshine, D.E.; Atwood, E.L.; Robbins, C.S.; Hughes, L.E.

    1969-01-01

    Results of tests for rickettsiae and viruses on 4,266 ticks taken from more than 10,000 birds, comprising 150 species, in the eastern United States indicated the presence of two agents: Rickettsia rickettsii and an agent of the typhus group. Infection with R. rickettsii was indicated in 24 pools of Haemaphysalis leporispalustris, five pools of Ixodes dentatus, one pool of Ixodes brunneus, and two pools that contained both I. dentatus and H. leporispalustris. The pools positive for R. rickettsii were from a variety of locations in the eastern U. S. The typhus-group agent was demonstrated only once, in a single pool of H. leporispalustris taken at Kent Point, Maryland. A strain of R. rickettsii was isolated from a pool of 21 larval H. leporispalustris collected at Ocean City, Maryland. This agent possessed several characteristics of other strains of low virulence isolated previously in this region by various authors.

  13. Detection of Rickettsia rickettsii DNA in clinical specimens by using polymerase chain reaction technology.

    Tzianabos, T; Anderson, B E; McDade, J E

    1989-01-01

    A polymerase chain reaction (PCR) procedure for detecting rickettsial DNA was developed and shown to be specific for Rickettsia rickettsii and R. conorii, the etiologic agents of Rocky Mountain spotted fever (RMSF) and Boutonneuse fever, respectively. Blood clots were obtained from nine confirmed RMSF patients and six controls and analyzed for the presence of rickettsial DNA by the PCR method. A defined region of the rickettsial genome was successfully amplified from seven of the nine clinica...

  14. Molecular Investigations of Rickettsia helvetica Infection in Dogs, Foxes, Humans, and Ixodes Ticks▿

    Boretti, Felicitas S.; Perreten, Andrea; Meli, Marina L.; Cattori, Valentino; Willi, Barbara; Wengi, Nicole; Hornok, Sándor; Honegger, Hanspeter; Hegglin, Daniel; Woelfel, Roman; Reusch, Claudia E.; Lutz, Hans; Hofmann-Lehmann, Regina

    2009-01-01

    Rickettsia helvetica, a tick-borne member of the spotted-fever-group rickettsiae, is a suspected pathogen in humans; however, its role in animals is unknown. The aims of this study were to establish a R. helvetica-specific real-time TaqMan PCR assay and apply it to the analysis of tick vectors (to determine potential exposure risk) and blood samples from Canidae and humans (to determine prevalence of infection). The newly designed 23S rRNA gene assay for R. helvetica was more sensitive than a published citrate synthase gene (gltA) assay for several rickettsiae. Blood samples from 884 dogs, 58 foxes, and 214 human patients and 2,073 ticks (Ixodes spp.) collected from either vegetation or animals were analyzed. Although the maximal likelihood estimate of prevalence was 12% in unfed ticks and 36% in ticks collected from animals, none of the 1,156 blood samples tested PCR positive. Ticks from cats were more frequently PCR positive than ticks from dogs. Sequencing of the 23S rRNA and/or the gltA gene of 17 tick pools confirmed the presence of R. helvetica. Additionally, Rickettsia monacensis, which has not been previously found in Switzerland, was identified. In conclusion, R. helvetica was frequently detected in the tick population but not in blood samples. Nevertheless, due to the broad host range of Ixodes ticks and the high rate of infestation with this agent (i.e., R. helvetica was 13 times more frequent in unfed ticks than the tick-borne encephalitis virus), many mammals may be exposed to R. helvetica. The PCR assay described here represents an important tool for studying this topic. PMID:19329665

  15. Molecular Investigations of Rickettsia helvetica infection in dogs, foxes, humans, and Ixodes ticks.

    Boretti, Felicitas S; Perreten, Andrea; Meli, Marina L; Cattori, Valentino; Willi, Barbara; Wengi, Nicole; Hornok, Sándor; Honegger, Hanspeter; Hegglin, Daniel; Woelfel, Roman; Reusch, Claudia E; Lutz, Hans; Hofmann-Lehmann, Regina

    2009-05-01

    Rickettsia helvetica, a tick-borne member of the spotted-fever-group rickettsiae, is a suspected pathogen in humans; however, its role in animals is unknown. The aims of this study were to establish a R. helvetica-specific real-time TaqMan PCR assay and apply it to the analysis of tick vectors (to determine potential exposure risk) and blood samples from Canidae and humans (to determine prevalence of infection). The newly designed 23S rRNA gene assay for R. helvetica was more sensitive than a published citrate synthase gene (gltA) assay for several rickettsiae. Blood samples from 884 dogs, 58 foxes, and 214 human patients and 2,073 ticks (Ixodes spp.) collected from either vegetation or animals were analyzed. Although the maximal likelihood estimate of prevalence was 12% in unfed ticks and 36% in ticks collected from animals, none of the 1,156 blood samples tested PCR positive. Ticks from cats were more frequently PCR positive than ticks from dogs. Sequencing of the 23S rRNA and/or the gltA gene of 17 tick pools confirmed the presence of R. helvetica. Additionally, Rickettsia monacensis, which has not been previously found in Switzerland, was identified. In conclusion, R. helvetica was frequently detected in the tick population but not in blood samples. Nevertheless, due to the broad host range of Ixodes ticks and the high rate of infestation with this agent (i.e., R. helvetica was 13 times more frequent in unfed ticks than the tick-borne encephalitis virus), many mammals may be exposed to R. helvetica. The PCR assay described here represents an important tool for studying this topic. PMID:19329665

  16. Detection of Rickettsia helvetica DNA from peripheral blood of Sika deer (Cervus nippon yesoensis) in Japan.

    Inokuma, Hisashi; Seino, Nobutaka; Suzuki, Masatsugu; Kaji, Koichi; Takahashi, Hiroshi; Igota, Hiromasa; Inoue, Satoshi

    2008-01-01

    Partial nucleotide sequences of the citrate synthase and 17-kDa genes of Rickettsia helvetica were detected from peripheral blood samples of Sika deer (Cervus nippon yesoensis) in Hokkaido, Japan. Results suggest the presence of a rickettsiemia associated with R. helvetica. This is the first evidence of R. helvetica infection in Sika deer and indicates that this species may represent a potential reservoir host of R. helvetica in Japan. PMID:18263833

  17. Ehrlichia phagocytophila genogroup rickettsiae in ixodid ticks from California collected in 1995 and 1996.

    Barlough, J E; Madigan, J E; Kramer, V. L.; Clover, J R; Hui, L T; Webb, J P; Vredevoe, L K

    1997-01-01

    A total of 1,246 ixodid ticks collected in 1995 and 1996 from seven California counties were examined for the presence of Ehrlichia phagocytophila genogroup rickettsiae by using a nested PCR technique. Of 1,112 adult Ixodes pacificus Cooley and Kohls ticks tested, nine pools, each containing five ticks, were positive (minimum percentage of ticks harboring detectable ehrlichiae, 0.8%). Positive ticks were limited to four of the seven counties (Sonoma, El Dorado, Santa Cruz, and Orange). In San...

  18. A prospective study evaluating the presence of Rickettsia in Danish patients with sarcoidosis

    Svendsen, Claus Bo; Milman, Nils; Nielsen, Henrik Winther;

    2009-01-01

    prospectively enrolled in the study. The diagnosis was confirmed by biopsy in 18 and by clinical characteristics in 8 patients; 11 patients with different non-sarcoid lung diseases were recruited as controls. We obtained information regarding tick exposure and sarcoid disease manifestations by a structured...... difference in the reported frequency of tick bite between patients and controls. In conclusion, we found no evidence of Rickettsia being involved in the pathogenesis of sarcoidosis in Denmark....

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

    Mediannikov, Oleg; Davoust, B; Socolovschi, C.; Tshilolo, L.; Raoult, Didier; Parola, P

    2012-01-01

    Little is known about the prevalence of spotted fever group (SFG) rickettsiae in ticks and fleas in the Democratic Republic of the Congo. In 2008, 12 Amblyomma compressum ticks were collected from 3 pangolins (Manis gigantea). Two Haemaphysalis punctaleachi ticks were collected from 2 African civets (Civettictis civetta congica), and one was collected from an antelope (Onotragus leche). A total of 111 Rhipicephalus sanguineus ticks, 23 Ctenocephalides canis fleas, 39 C. felts fleas, and 5 Tri...

  20. Prevalence and Infection Load Dynamics of Rickettsia felis in Actively Feeding Cat Fleas

    Reif, Kathryn E.; Stout, Rhett W.; Gretchen C Henry; Lane D Foil; Macaluso, Kevin R.

    2008-01-01

    Background Rickettsia felis is a flea-associated rickettsial pathogen recurrently identified in both colonized and wild-caught cat fleas, Ctenocephalides felis. We hypothesized that within colonized fleas, the intimate relationship between R. felis and C. felis allows for the coordination of rickettsial replication and metabolically active periods during flea bloodmeal acquisition and oogenesis. Methodology/Principal Findings A quantitative real-time PCR assay was developed to quantify R. fel...

  1. Nonselective Persistence of a Rickettsia conorii Extrachromosomal Plasmid during Mammalian Infection.

    Riley, Sean P; Fish, Abigail I; Garza, Daniel A; Banajee, Kaikhushroo H; Harris, Emma K; del Piero, Fabio; Martinez, Juan J

    2016-03-01

    Scientific analysis of the genus Rickettsia is undergoing a rapid period of change with the emergence of viable genetic tools. The development of these tools for the mutagenesis of pathogenic bacteria will permit forward genetic analysis of Rickettsia pathogenesis. Despite these advances, uncertainty still remains regarding the use of plasmids to study these bacteria in in vivo mammalian models of infection, namely, the potential for virulence changes associated with the presence of extrachromosomal DNA and nonselective persistence of plasmids in mammalian models of infection. Here, we describe the transformation of Rickettsia conorii Malish 7 with the plasmid pRam18dRGA[AmTrCh]. Transformed R. conorii stably maintains this plasmid in infected cell cultures, expresses the encoded fluorescent proteins, and exhibits growth kinetics in cell culture similar to those of nontransformed R. conorii. Using a well-established murine model of fatal Mediterranean spotted fever, we demonstrate that R. conorii(pRam18dRGA[AmTrCh]) elicits the same fatal outcomes in animals as its untransformed counterpart and, importantly, maintains the plasmid throughout infection in the absence of selective antibiotic pressure. Interestingly, plasmid-transformed R. conorii was readily observed both in endothelial cells and within circulating leukocytes. Together, our data demonstrate that the presence of an extrachromosomal DNA element in a pathogenic rickettsial species does not affect either in vitro proliferation or in vivo infectivity in models of disease and that plasmids such as pRam18dRGA[AmTrCh] are valuable tools for the further genetic manipulation of pathogenic rickettsiae. PMID:26755154

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

    Richard Pacheco

    2008-08-01

    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.

  3. Arsenophonus nasoniae and Rickettsiae Infection of Ixodes ricinus Due to Parasitic Wasp Ixodiphagus hookeri.

    Monika Bohacsova

    Full Text Available Arsenophonus nasoniae, a male-killing endosymbiont of chalcid wasps, was recently detected in several hard tick species. Following the hypothesis that its presence in ticks may not be linked to the direct occurrence of bacteria in tick's organs, we identified A. nasoniae in wasps emerging from parasitised nymphs. We confirmed that 28.1% of Ixodiphagus hookeri wasps parasitizing Ixodes ricinus ticks were infected by A. nasoniae. Moreover, in examined I. ricinus nymphs, A. nasoniae was detected only in those, which were parasitized by the wasp. However, in part of the adult wasps as well as in some ticks that contained wasp's DNA, we did not confirm A. nasoniae. We also found, that in spite of reported male-killing, some newly emerged adult wasp males were also infected by A. nasoniae. Additionally, we amplified the DNA of Rickettsia helvetica and Rickettsia monacensis (known to be Ixodes ricinus-associated bacteria in adult parasitoid wasps. This may be related either with the digested bacterial DNA in wasp body lumen or with a role of wasps in circulation of rickettsiae among tick vectors.

  4. Emerging Tick-borne Rickettsia and Ehrlichia at Joint Base Langley-Eustis, Fort Eustis, Virginia.

    Miller, Melissa K; Jiang, Ju; Truong, Melissa; Yarina, Tamasin; Evans, Holly; Christensen, Timothy P; Richards, Allen L

    2016-01-01

    Four species of ticks known to parasitize humans (Amblyomma americanum (lone star tick), Dermacentor variabilis (American dog tick), Amblyomma maculatum (Gulf Coast tick), and Ixodes scapularis (black-legged tick)) were collected at Joint Base Langley-Eustis, Fort Eustis, Virginia during 2009. These ticks were tested individually (adults and nymphs) and in pools of 15 (larvae) for pathogens of public health importance within the genera: Rickettsia, Borrelia, and Ehrlichia, by quantitative real-time polymerase chain reaction (qPCR) assays and, where appropriate, multilocus sequence typing (MLST). Of the 340 A americanum ticks tested, a minimum of 65 (19%), 4 (1%), 4 (1%), and one (<1%) were positive for Rickettsia amblyommii, B lonestari, E ewingii and E chaffeensis, respectively. One of 2 (50%) A maculatum ticks collected was found to be positive for R parkeri by MLST and qPCR analyses. All 33 D variabilis ticks were negative for evidence of rickettsial infections. Likewise, no pathogenic organisms were detected from the single Ixodes scapularis tick collected. Pathogenic rickettsiae and ehrlichiae are likely emerging and cause under-recognized diseases, which threaten people who live, work, train, or otherwise engage in outdoor activities at, or in the vicinity of, Fort Eustis, Virginia. PMID:27613206

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

    Baba, Kenji; Kaneda, Toshiya; Nishimura, Hitoshi; Sato, Hiroshi

    2013-02-01

    Rickettsial infection in feral raccoons (Procyon lotor) in the western part of Japan (Shimane, Fukuoka, Saga and Nagasaki Prefectures) was surveyed by a nested polymerase chain reaction (PCR) assay detecting the rickettsial citrate synthase (gltA) gene. Four of one hundred and ninety-four feral raccoon spleens (2.1%) were positive for Rickettsia spp. One gltA gene sequence was identical to R. helvetica, whereas the other 3 sequences were identical and had the highest similarity (98.4%) to R. amblyommii. Simultaneously, we determined a partial sequence of the rickettsial 17-kilodalton (17K) genus-common antigen gene in the later 3 raccoon samples. Their sequences were identical and had the highest similarity (98.5%) to Rickettsia sp. Hj126. Based on the sequences of gltA and 17K antigen genes, these raccoons might be infected with spotted fever group (SFG) rickettsia most closely related to R. amblyommii and/or Rickettsia sp. Hj126. Feral raccoons may be a susceptible reservoir for SFG rickettsiae in Japan. PMID:22986299

  6. Rickettsiae in arthropods collected from the North African Hedgehog (Atelerix algirus) and the desert hedgehog (Paraechinus aethiopicus) in Algeria.

    Khaldi, Mourad; Socolovschi, Cristina; Benyettou, Meryam; Barech, Ghania; Biche, Mohamed; Kernif, Tahar; Raoult, Didier; Parola, Philippe

    2012-03-01

    Hedgehogs have become a popular pet despite their potential role in zoonotic disease transmission. We conducted an entomological study in a mountainous region of northeast Algeria in which we collected 387 fleas (Archeopsylla erinacei) and 342 ticks (Rhipicephalus sanguineus and Haemaphysalis erinacei) from Paraechinus aethiopicus and Atelerix algirus hedgehogs. Of the hedgehogs sampled, 77.7% and 91% were infested with fleas and ticks, respectively. Significantly more ticks and fleas were collected from A. algirus than from P. aethiopicus. Rickettsia felis was detected in 95.5% of fleas and R. massiliae was detected in 6.25% of Rh. sanguineus ticks by molecular tools. A new Rickettsia species of the spotted fever group was detected in 11.25% of Rh. sanguineus and in 77% of H. erinacei ticks. Overall, we show that hedgehogs can act as hosts for ectoparasites infected with several rickettsial agents. These data justify a more detailed investigation of animal reservoirs for Rickettsiae. PMID:22222114

  7. Detection of Borrelia burgdorferi sensu lato and spotted fever group rickettsiae in hard ticks (Acari, Ixodidae) parasitizing bats in Poland.

    Piksa, Krzysztof; Stańczak, Joanna; Biernat, Beata; Górz, Andrzej; Nowak-Chmura, Magdalena; Siuda, Krzysztof

    2016-04-01

    A total of 491 Ixodes vespertilionis and 8 Ixodes ricinus collected from bats and cave walls in southern Poland between 2010 and 2012 were examined by the polymerase chain reaction for tick-transmitted pathogens. PCR analysis for Borrelia burgdorferi s.l., Rickettsia spp., and Anaplasma phagocytophilum yielded negative results for all I. vespertilionis. DNA of Rickettsia helvetica was detected in three specimens of I. ricinus attached to Rhinolophus hipposideros or Myotis myotis, while Borrelia garinii was found in one tick parasitizing Myotis daubentonii. These pathogens were recorded for the first time in hard ticks that parasitized bats. PMID:26833325

  8. Notes from the Field: Rickettsia parkeri Rickettsiosis - Georgia, 2012-2014.

    Straily, Anne; Feldpausch, Amanda; Ulbrich, Carl; Schell, Kiersten; Casillas, Shannon; Zaki, Sherif R; Denison, Amy M; Condit, Marah; Gabel, Julie; Paddock, Christopher D

    2016-01-01

    During 2012-2014, five cases of Rickettsia parkeri rickettsiosis were identified by a single urgent care practice in Georgia, located approximately 40 miles southwest of Atlanta. Symptom onset occurred during June-October, and all patients had a known tick bite. Patients ranged in age from 27 to 72 years (median = 53 years), and all were male. The most commonly reported initial signs were erythema (n = 3) and swelling (n = 2) at the site of the bite. Two patients reported fever and a third patient reported a rash and lymphadenopathy without fever. Other symptoms included myalgia (n = 3), chills (n = 3), fatigue (n = 2), arthralgia (n = 2), and headache (n = 2). Eschar biopsy specimens were collected from each patient using a 4-mm or 5-mm punch and placed in 10% neutral buffered formalin or sterile saline. These specimens were tested by immunohistochemical (IHC) stains, quantitative polymerase chain reaction (qPCR) assays, or cell culture isolation to determine if there was evidence of infection with a Rickettsia species (1). IHC evidence of spotted fever group rickettsiae was found in the eschar biopsy specimens in all five cases. In four cases, the biopsy specimens were also positive for R. parkeri by qPCR. The fifth case (specimen positive only by IHC testing) was considered a probable R. parkeri case based on clinical signs and symptoms. R. parkeri was grown in cell culture from one specimen from which isolation was attempted. All patients were treated with oral doxycycline (100 mg twice daily) for a minimum of 10 days, and all recovered. PMID:27442517

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

    Eliane M Piranda

    2008-11-01

    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.

  10. Detection of Borrelia, Ehrlichia, and Rickettsia spp. in ticks in northeast Missouri.

    Hudman, D A; Sargentini, N J

    2016-07-01

    We evaluated Amblyomma americanum (lone star tick) and Dermacentor variabilis (American dog tick) in northeast Missouri for the presence of Borrelia, Ehrlichia, and Rickettsia bacteria. We collected actively questing ticks from four sites within Adair County, Missouri. A total of 15,162 ticks were collected, of which 13,980 were grouped in 308 pools (lone star ticks, 288 pools; American dog ticks, 20 pools) and tested for presence/absence of bacteria using polymerase chain reaction. Infection rates were calculated as the maximum likelihood estimation (MLE) with 95% confidence intervals (CI). Of the 308 pools tested, 229 (74.4%) were infected with bacteria and the overall MLE of the infection rate per 100 ticks was calculated as 2.9% (CI 2.61-3.21). Infection rates varied among life stages, 28.6% (CI 23.89-33.97) in adults, 7.0% (CI 5.10-9.86) in nymphs, and 1.0% (CI 0.75-1.20) in larvae. In the 116 adult lone star pools, infection rates were calculated for Borrelia lonestari (1.4%), Borrelia spp. (2.7%), Ehrlichia chaffeensis (6.1%), Ehrlichia ewingii (3.3%), Rickettsia amblyommii (18.3%), and Rickettsia montanensis (0.4%). Infection rates for the 52 nymphal lone star pools were calculated as B. lonestari (1.03%), Borrelia spp. (0.40%), E. chaffeensis (2.02%), E. ewingii (0.24%), and R. amblyommii (2.70%). In the 20 adult American dog tick pools, infection rates were determined as E. chaffeensis (9.47%), E. ewingii (5.47%), and R. montanensis (8.06%). Eight Borrelia samples were sequenced with five 99-100% identical to B. burgdorferi (s.l.) and three 99% identical to B. lonestari. Eight samples were sequenced for E. chaffeensis (all 99-100% identical) and one sample was sequenced for E. ewingii (99% identical). Seven samples were sequenced for Rickettsia and three were 99% identical to R. montanensis and four were 100% identical to R. amblyommii. This study demonstrates B. lonestari, E. chaffeensis, E. ewingii, R. amblyommii, and R. montanensis in northeast

  11. A Confirmed Case of Rickettsia parkeri Infection in a Traveler from Uruguay

    Portillo, Aránzazu; García-García, Concepción; Sanz, M. Mercedes; Santibáñez, Sonia; José M. Venzal; Oteo, José A

    2013-01-01

    The first confirmed case of Rickettsia parkeri infection in Uruguay is reported. To date, in South America, molecularly confirmed cases of human infection have been found in Argentina and probably, Brazil. Our patient returned to Spain after a 7-day trip to Colonia Suiza (Southwestern Uruguay). He presented fever (39°C), chills, and two eschars (tache noire-like) surrounded by an indurated, erythematous halo on the inner side of the left ankle besides a maculopapular rash on the legs. After t...

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

    Ibarra, V; Portillo, A; Palomar, A M; Sanz, M M; Metola, L; Blanco, J R; Oteo, J A

    2012-08-01

    In 1996, the first human case of infection by Rickettsia sibirica subsp. mongolitimonae was described in France. Subsequently, other human cases were reported in the same country. The acronym LAR (lymphangitis-associated rickettsiosis) has been proposed to designate this disease because lymphangitis is one of the main clinical manifestations. Later, a few more cases were described in Portugal, South Africa, Egypt, Greece and Spain. We report a case of R. sibirica mongolitimonae infection as a cause of septic shock in a Spanish patient living in La Rioja (northern Spain). In addition, the broad clinical spectrum of this tick-borne disease is discussed. PMID:22548679

  13. Antibodies against spotted fever group Rickettsia sp., in horses of the colombian Orinoquia

    Diego A. Riveros-Pinilla; Leidy Acevedo G; Andrés F. Londoño; Agustín Góngora O

    2015-01-01

    ABSTRACT Objective. It was determined the presence of antibodies against Rickettsia sp. of the spotted fever group, in horses of 8 municipalities of the Colombian Orinoquia. Matherials and methods. A cross-sectional study was conducted on 246 sera from apparently healthy horses and processed by the indirect immunofluorescence test (IFI). Results. General seropositivity was (2.85%; 7/246), while by municipalities the results were, Arauca (9.1%; 2/22), Saravena (5.6%; 1/18), San José del Guav...

  14. Which Way In? The RalF Arf-GEF Orchestrates Rickettsia Host Cell Invasion.

    Kristen E Rennoll-Bankert

    2015-08-01

    Full Text Available Bacterial Sec7-domain-containing proteins (RalF are known only from species of Legionella and Rickettsia, which have facultative and obligate intracellular lifestyles, respectively. L. pneumophila RalF, a type IV secretion system (T4SS effector, is a guanine nucleotide exchange factor (GEF of ADP-ribosylation factors (Arfs, activating and recruiting host Arf1 to the Legionella-containing vacuole. In contrast, previous in vitro studies showed R. prowazekii (Typhus Group RalF is a functional Arf-GEF that localizes to the host plasma membrane and interacts with the actin cytoskeleton via a unique C-terminal domain. As RalF is differentially encoded across Rickettsia species (e.g., pseudogenized in all Spotted Fever Group species, it may function in lineage-specific biology and pathogenicity. Herein, we demonstrate RalF of R. typhi (Typhus Group interacts with the Rickettsia T4SS coupling protein (RvhD4 via its proximal C-terminal sequence. RalF is expressed early during infection, with its inactivation via antibody blocking significantly reducing R. typhi host cell invasion. For R. typhi and R. felis (Transitional Group, RalF ectopic expression revealed subcellular localization with the host plasma membrane and actin cytoskeleton. Remarkably, R. bellii (Ancestral Group RalF showed perinuclear localization reminiscent of ectopically expressed Legionella RalF, for which it shares several structural features. For R. typhi, RalF co-localization with Arf6 and PI(4,5P2 at entry foci on the host plasma membrane was determined to be critical for invasion. Thus, we propose recruitment of PI(4,5P2 at entry foci, mediated by RalF activation of Arf6, initiates actin remodeling and ultimately facilitates bacterial invasion. Collectively, our characterization of RalF as an invasin suggests that, despite carrying a similar Arf-GEF unknown from other bacteria, different intracellular lifestyles across Rickettsia and Legionella species have driven divergent roles

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

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

    1999-01-01

    Embora o diagnóstico da febre maculosa baseie-se em sinais e sintomas característicos, o mesmo requer confirmação laboratorial, pois existem alguns diagnósticos diferenciais possíveis como meningococcemia, leptospirose, infecção por enterovírus e febre tifóide. A confirmação laboratorial pode ser feita através da pesquisa de anticorpos específicos, possível somente alguns dias após o aparecimento da doença, através do isolamento do agente em amostras de sangue e/ou biópsia de pele, e ainda, d...

  16. Seroprevalence of antibodies to Rickettsia typhi in the Waikato region of New Zealand.

    Lim, M Y; Weinstein, P; Bell, A; Hambling, T; Tompkins, D M; Slaney, D

    2016-08-01

    The first reported New Zealand-acquired case of murine typhus occurred near Auckland in 1989. Since then, 72 locally acquired cases have been recorded from northern New Zealand. By 2008, on the basis of the timing and distribution of cases, it appeared that murine typhus was escalating and spreading southwards. To explore the presence of Rickettsia typhi in the Waikato region, we conducted a seroprevalence study, using indirect immunofluorescence, Western blot, and cross-adsorption assays of blood donor samples. Of 950 human sera from Waikato, 12 (1·3%) had R. typhi antibodies. The seroprevalence for R. typhi was slightly higher in northern Waikato (1·4%) compared to the south (1·2%; no significant difference, χ 2 P = 0·768 at P < 0·05). Our results extend the reported southern range of R. typhi by 140 km and indicate it is endemic in Waikato. Evidence of past Rickettsia felis infections was also detected in six sera. Globally, R. felis is an emerging disease of concern and this pathogen should also be considered when locally acquired rickettsiosis is suspected. If public health interventions are to be implemented to reduce the risk of rickettsioses as a significant public health problem, improvements in rickettsial diagnostics and surveillance will be necessary. PMID:27040715

  17. Proteome analysis and serological characterization of surface-exposed proteins of Rickettsia heilongjiangensis.

    Yong Qi

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

  18. Antibodies against spotted fever group Rickettsia sp., in horses of the colombian Orinoquia

    Diego A. Riveros-Pinilla

    2015-11-01

    Full Text Available Objective. It was determined the presence of antibodies against Rickettsia sp. of the spotted fever group, in horses of 8 municipalities of the Colombian Orinoquia. Matherials and methods. A cross-sectional study was conducted on 246 sera from apparently healthy horses and processed by the indirect immunofluorescence test (IFI. Results. General seropositivity was (2.85%; 7/246, while by municipalities the results were, Arauca (9.1%; 2/22, Saravena (5.6%; 1/18, San José del Guaviare (4.9%; 2/41, San Martín (3.8%; 1/26, Yopal (1.9%; 1/52. It was not identified the presence of antibodies in Puerto López (0/52, Puerto Gaitán (0/15 and Villavicencio (0/20. Four of the positive samples presented titles of 1:64, while the remaining 3 1:128. Conclusions. It shows the circulation of Rickettsia sp. of the Spotted Fever Group in horses in the region of the Colombian Orinoquia, suggesting the need for further studies to understand the ecoepidemiology of municipalities with presence of seropositive.

  19. Prevalence of Rickettsia species in Dermacentor variabilis ticks from Ontario, Canada.

    Wood, Heidi; Dillon, Liz; Patel, Samir N; Ralevski, Filip

    2016-07-01

    Relatively little is known about the prevalence of rickettsial species in Dermacentor ticks in eastern Canada. In this study, Dermacentor ticks from the province of Ontario, Canada, were tested for the presence of spotted fever group rickettsial (SFGR) species, Coxiella burnetii and Francisella tularensis. Rickettsia rickettsii was not detected in any ticks tested, but R. montanensis was detected at a prevalence of 2.2% in D. variabilis (17/778). Two other SFGR species, R. parkeri and Candidatus R. andeanae, were detected individually in 2 Amblyomma maculatum ticks. Rickettsia peacockii, a non-pathogenic endosymbiont, was detected in two D. andersonii ticks. Given the highly abundant nature of D. variabilis, surveillance for human pathogens in this species of tick has important public health implications, but the lack of detection of known human pathogens indicates a low risk of infection via this tick species in Ontario. However, the detection of R. parkeri in an adventive A. maculatum tick indicates that health care providers should be aware of the possibility of spotted fever rickettsioses in individuals with a history of travel outside of Ontario and symptoms compatible with a spotted fever rickettsiosis. Coxiella burnetii and Francisella tularensis, human pathogens also potentially transmitted by D. variabilis, were not detected in a subset of the ticks. PMID:27318438

  20. Isolation and characterization of the dnaA gene of Rickettsia prowazekii

    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)

  1. Multispacer Typing (MST) of Spotted Fever Group Rickettsiae Isolated from Humans and Rats in Chengmai County, Hainan Province, China.

    Cheng, Xueqin; Jin, Yuming; Lao, Shijun; Huang, Changhe; Huang, Fang; Jia, Pengben; Zhang, Lijuan

    2014-09-01

    Spotted fever caused by spotted fever group rickettsiae (SFGR) is found throughout China. During 2007-2008, 28 human SFGR isolates and 34 rat SFGR isolates including 15 isolates from Rattus fulvescens, 5 isolates from R. edwardsi, 7 isolates from Callosciurus erythraeus roberti and 7 isolates from Dremomys rufigenis) were obtained from L929 cell culture. Previous research indicated that the 62 strains of SFGR mentioned above shared not only the same serophenotype but also 100% of identity sequences of 16S rRNA, gltA, ompA, groEL and 17KD, which enabled us to apply multispacer typing (MST) to the 62 SFGR isolates in the study. Six primer pairs, which were used for typing of Rickettsia rickettsii and Rickettsia conorii, were chosen, and the results exhibited greater nucleotide polymorphisms among the 62 isolates tested. A total of 48 distinct genotypes were identified. The dominant genotype, represented by h3 isolates, accounted for 21.7% (13/60) of the isolates tested, and the remaining 47 genotypes were all unique. Phylogenetic analysis showed that all the 48 genotypes could be classified in the same clade, while the genetically related strain, R. heilongjiangensis, was close but not the same as the cluster. We concluded that the genetically diverse of spotted fever group rickettsiae strains are endemic in Chengmai County, Hainan Province, China. PMID:25324688

  2. Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES

    PENICHE-LARA, Gaspar; Dzul-Rosado, Karla; PÉREZ-OSORIO, Carlos; Zavala-Castro, Jorge

    2015-01-01

    Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chai...

  3. Evidence for proteolytic cleavage of the 120-kilodalton outer membrane protein of rickettsiae: identification of an avirulent mutant deficient in processing.

    Hackstadt, T; Messer, R; Cieplak, W; Peacock, M G

    1992-01-01

    The 120-kDa rickettsial outer membrane protein (rOmpB) is encoded by a gene with the capacity to encode a protein of approximately 168 kDa. The carboxy-terminal end of the molecule is apparently cleaved to yield 120- and 32-kDa products. Both polypeptides are surface exposed and remain associated with the outer membrane of intact rickettsiae. All species of rickettsiae examined display similar cleavage of rOmpB. Comparison of diverse species of rickettsiae demonstrate a conserved N terminus o...

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

    Rui Cruz

    2014-08-01

    Full Text Available 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

  5. Molecular Detection of Zoonotic Rickettsiae and Anaplasma spp. in Domestic Dogs and Their Ectoparasites in Bushbuckridge, South Africa.

    Kolo, Agatha O; Sibeko-Matjila, Kgomotso P; Maina, Alice N; Richards, Allen L; Knobel, Darryn L; Matjila, Paul T

    2016-04-01

    Members of the order Rickettsiales are small, obligate intracellular bacteria that are vector-borne and can cause mild to fatal diseases in humans worldwide. There is little information on the zoonotic rickettsial pathogens that may be harbored by dogs from rural localities in South Africa. To characterize rickettsial pathogens infecting dogs, we screened 141 blood samples, 103 ticks, and 43 fleas collected from domestic dogs in Bushbuckridge Municipality, Mpumalanga Province of South Africa, between October 2011 and May 2012 using the reverse line blot (RLB) and Rickettsia genus and species-specific quantitative real-time PCR (qPCR) assays. Results from RLB showed that 49% of blood samples and 30% of tick pools were positive for the genus-specific probes for Ehrlichia/Anaplasma; 16% of the blood samples were positive for Ehrlichia canis. Hemoparasite DNA could not be detected in 36% of blood samples and 30% of tick pools screened. Seven (70%) tick pools and both flea pools were positive for Rickettsia spp; three (30%) tick pools were positive for Rickettsia africae; and both flea pools (100%) were positive for Rickettsia felis. Sequencing confirmed infection with R. africae and Candidatus Rickettsia asemboensis; an R. felis-like organism from one of the R. felis-positive flea pools. Anaplasma sp. South Africa dog strain (closely related to Anaplasma phagocytophilum), A. phagocytophilum, and an Orientia tsutsugamushi-like sequence were identified from blood samples. The detection of emerging zoonotic agents from domestic dogs and their ectoparasites in a rural community in South Africa highlights the potential risk of human infection that may occur with these pathogens. PMID:26974185

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

    Fernanda Aparecida Nieri-Bastos

    2014-04-01

    Full Text Available 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.

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

    Andrew Woodard

    Full Text Available 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.

  8. Featured Organism: Reductive Evolution in Bacteria: Buchnera sp., Rickettsia Prowazekii and Mycobacterium Leprae

    Jo Wixon

    2001-01-01

    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.

  9. Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES

    Gaspar PENICHE-LARA

    2015-04-01

    Full Text Available Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study’s results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

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

    Wenping Gong

    Full Text Available 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.

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

    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)

  12. Genomic diversification in strains of Rickettsia felis Isolated from different arthropods.

    Gillespie, Joseph J; Driscoll, Timothy P; Verhoeve, Victoria I; Utsuki, Tadanobu; Husseneder, Claudia; Chouljenko, Vladimir N; Azad, Abdu F; Macaluso, Kevin R

    2015-01-01

    Rickettsia felis (Alphaproteobacteria: Rickettsiales) is the causative agent of an emerging flea-borne rickettsiosis with worldwide occurrence. Originally described from the cat flea, Ctenocephalides felis, recent reports have identified R. felis from other flea species, as well as other insects and ticks. This diverse host range for R. felis may indicate an underlying genetic variability associated with host-specific strains. Accordingly, to determine a potential genetic basis for host specialization, we sequenced the genome of R. felis str. LSU-Lb, which is an obligate mutualist of the parthenogenic booklouse Liposcelis bostrychophila (Insecta: Psocoptera). We also sequenced the genome of R. felis str. LSU, the second genome sequence for cat flea-associated strains (cf. R. felis str. URRWXCal2), which are presumably facultative parasites of fleas. Phylogenomics analysis revealed R. felis str. LSU-Lb diverged from the flea-associated strains. Unexpectedly, R. felis str. LSU was found to be divergent from R. felis str. URRWXCal2, despite sharing similar hosts. Although all three R. felis genomes contain the pRF plasmid, R. felis str. LSU-Lb carries an additional unique plasmid, pLbaR (plasmid of L. bostrychophila associated Rickettsia), nearly half of which encodes a unique 23-gene integrative conjugative element. Remarkably, pLbaR also encodes a repeats-in-toxin-like type I secretion system and associated toxin, heretofore unknown from other Rickettsiales genomes, which likely originated from lateral gene transfer with another obligate intracellular parasite of arthropods, Cardinium (Bacteroidetes). Collectively, our study reveals unexpected genomic diversity across three R. felis strains and identifies several diversifying factors that differentiate facultative parasites of fleas from obligate mutualists of booklice. PMID:25477419

  13. Why are there so few Rickettsia conorii conorii-infected Rhipicephalus sanguineus ticks in the wild?

    Cristina Socolovschi

    Full Text Available BACKGROUND: Rickettsia conorii conorii is the etiological agent of Mediterranean spotted fever, which is transmitted by the brown dog tick, Rhipicephalus sanguineus. The relationship between the Rickettsia and its tick vector are still poorly understood one century after the first description of this disease. METHODOLOGY/PRINCIPAL FINDINGS: An entomological survey was organized in Algeria to collect ticks from the houses of patients with spotted fever signs. Colonies of R. conorii conorii-infected and non-infected ticks were established under laboratory conditions. Gimenez staining and electron microscopy on the ovaries of infected ticks indicated heavy rickettsial infection. The transovarial transmission of R. conorii conorii in naturally infected Rh. sanguineus ticks was 100% at eleven generations, and the filial infection rate was up to 99% according to molecular analyses. No differences in life cycle duration were observed between infected and non-infected ticks held at 25°C, but the average weight of engorged females and eggs was significantly lower in infected ticks than in non-infected ticks. The eggs, larvae and unfed nymphs of infected and non-infected ticks could not tolerate low (4°C or high (37°C temperatures or long starvation periods. R. conorii conorii-infected engorged nymphs that were exposed to a low or high temperature for one month experienced higher mortality when they were transferred to 25°C than non-infected ticks after similar exposure. High mortality was observed in infected adults that were maintained for one month at a low or high temperature after tick-feeding on rabbits. CONCLUSION/SIGNIFICANCE: These preliminary results suggest that infected quiescent ticks may not survive the winter and may help explain the low prevalence of infected Rh. sanguineus in nature. Further investigations on the influence of extrinsic factors on diapaused R. conorii-infected and non-infected ticks are required.

  14. Identification of Orientia tsutsugamushi,spotted fever group and typhus group Rickettsia by duplex and nested PCR methods

    M-C Luan; D-Z Yu; L Tang; L-J Zhang

    2008-01-01

    Objective:To identify members of genera of rickettsia and O.tsutsugamushi simultaneously.Methods:Rapid and duplex and nested PCR methods have been established by designing primers based on the conserved re-gions of heat shock protein GroEL gene.345 mouse viscera samples including liver,spleen and kidney,96 Xe-nopsylla cheopis and 32 chiggers collected from Hongta areas of Yuxi city,Yunnan province were tested by the new PCR methods.Results:The result of the study showed that the new PCR methods could identify most members of genera -Rickettsia and Orientia simultaneously with 100% specificity and its sensitivity could test one copy per microliter.The results of detection prevalence of rickettsioses in mouse,flea and mites DNA sam-ples showed that the total rickettsia infection rate in mouse was 34.78% (120 /345).The total infection rates in R.typhi,O.t Karp and R.sibirica of mouse samples were 28.12% (97 /345),19.71% (68 /345)and 0. 29% (1 /345)respectively.Co-infection rates in R.typhi and O.t Karp of mouse samples were 13.33% (46 /345).O.t Karp type has been the main epidemic strain in these areas.Conclusion:We concluded that this PCR method could be used to detect multi-genera rickettsia simultaneously.Molecular evidences provided in this and previous studies strongly support that Hongta areas of Yuxi city are a natural focus for typhus and scrub typhus with the common occurrence of their confection.

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

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

    1995-01-01

    In an effort to find a potential alternative treatment for scrub typhus, we evaluated the effectiveness of the standard drug doxycycline and the new macrolide azithromycin against a doxycycline-susceptible strain (Karp) and a doxycycline-resistant strain (AFSC-4) of Rickettsia tsutsugamushi. The antibiotics were tested in an in vitro assay system in which infected mouse fibroblast cells (L929) were incubated for 3 days in various concentrations of the drugs. Rickettsial growth was evaluated b...

  16. Molecular evidence of potential novel spotted fever group rickettsiae, Anaplasma and Ehrlichia species in Amblyomma ticks parasitizing wild snakes

    Kho, Kai Ling; Koh, Fui Xian; Tay, Sun Tee

    2015-01-01

    Background Amblyomma ticks parasitize a wide range of animals in tropical regions. This study describes the identification of Amblyomma ticks from wild snakes in Malaysia and the detection of potential human pathogens such as Rickettsia, Anaplasma, Ehrlichia and bartonellae in the ticks. Findings Twenty one adult ticks (twelve A. varanense and nine Amblyomma helvolum ticks) identified from seven Python molurus snakes in Sepang and a pool of six A. helvolum ticks from a Naja sumatrana snake in...

  17. Spotted fever Rickettsia species in Hyalomma and Ixodes ticks infesting migratory birds in the European Mediterranean area

    Wallmenius, Katarina; Barboutis, Christos; Fransson, Thord; Thomas G.T. Jaenson; Lindgren, Per-Eric; Nyström, Fredrik; Olsen, Bjorn; Salaneck, Erik; Nilsson, Kenneth

    2014-01-01

    Background: A few billion birds migrate annually between their breeding grounds in Europe and their wintering grounds in Africa. Many bird species are tick-infested, and as a result of their innate migratory behavior, they contribute significantly to the geographic distribution of pathogens, including spotted fever rickettsiae. The aim of the present study was to characterize, in samples from two consecutive years, the potential role of migrant birds captured in Europe as disseminators of Ric...

  18. Multispacer Typing (MST) of Spotted Fever Group Rickettsiae Isolated from Humans and Rats in Chengmai County, Hainan Province, China

    Cheng, Xueqin; Jin, Yuming; Lao, Shijun; Huang, Changhe; Huang, Fang; Jia, Pengben; Zhang, Lijuan

    2014-01-01

    Spotted fever caused by spotted fever group rickettsiae (SFGR) is found throughout China. During 2007–2008, 28 human SFGR isolates and 34 rat SFGR isolates including 15 isolates from Rattus fulvescens, 5 isolates from R. edwardsi, 7 isolates from Callosciurus erythraeus roberti and 7 isolates from Dremomys rufigenis) were obtained from L929 cell culture. Previous research indicated that the 62 strains of SFGR mentioned above shared not only the same serophenotype but also 100% of identity seq...

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

    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

    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 ...

  20. por valores

    Jazmín Díaz-Barrios

    2005-01-01

    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.

  1. Rickettsia parkeri: a Rickettsial pathogen transmitted by ticks in endemic areas for spotted fever rickettsiosis in southern Uruguay

    José M. Venzal

    2012-06-01

    Full Text Available 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.

  2. Diversity of Bartonella and Rickettsia spp. in Bats and Their Blood-Feeding Ectoparasites from South Africa and Swaziland

    Dietrich, Muriel; Tjale, Mabotse A.; Weyer, Jacqueline; Kearney, Teresa; Seamark, Ernest C. J.; Nel, Louis H.; Monadjem, Ara; Markotter, Wanda

    2016-01-01

    In addition to several emerging viruses, bats have been reported to host multiple bacteria but their zoonotic threats remain poorly understood, especially in Africa where the diversity of bats is important. Here, we investigated the presence and diversity of Bartonella and Rickettsia spp. in bats and their ectoparasites (Diptera and Siphonaptera) collected across South Africa and Swaziland. We collected 384 blood samples and 14 ectoparasites across 29 different bat species and found positive samples in four insectivorous and two frugivorous bat species, as well as their Nycteribiidae flies. Phylogenetic analyses revealed diverse Bartonella genotypes and one main group of Rickettsia, distinct from those previously reported in bats and their ectoparasites, and for some closely related to human pathogens. Our results suggest a differential pattern of host specificity depending on bat species. Bartonella spp. identified in bat flies and blood were identical supporting that bat flies may serve as vectors. Our results represent the first report of bat-borne Bartonella and Rickettsia spp. in these countries and highlight the potential role of bats as reservoirs of human bacterial pathogens. PMID:26999518

  3. Rickettsia helvetica and R. monacensis infections in immature Ixodes ricinus ticks derived from sylvatic passerine birds in west-central Poland.

    Biernat, Beata; Stańczak, Joanna; Michalik, Jerzy; Sikora, Bożena; Cieniuch, Stella

    2016-09-01

    The aim of this study was to assess the importance of forest passerine birds in spreading ixodid ticks infected with rickettsiae of spotted fever group (SFG) in sylvatic habitats in western Poland. In total, 834 immature Ixodes ricinus ticks were found on 64 birds of 11 species which were captured during the tick-questing season between May and September of 2006. Ground-foraging passerines hosted most of the ticks compared with arboreal species, and therefore, only the former group was included into a detailed analysis. Significant predominance of larvae over nymphs was observed (581 vs. 253, respectively). Blackbirds and song thrushes hosted 82 % (n = 681) of the ticks collected from all infested passerines. The overall prevalence range of SF rickettsiae (including Rickettsia helvetica and Rickettsia monacensis) in bird-derived ticks was 10.5-26.9 %, exceeding that in questing ticks, and in ticks feeding on rodents and deer reported earlier from the same study area. This high prevalence of infection in immature I. ricinus ticks feeding on passerine birds strongly implies that they are involved in the enzootic maintenance of spotted fever group rickettsiae in the tick vector populations occurring in sylvatic habitats. PMID:27164834

  4. Rickettsia-like organism infection in a freshwater cultured fish Ophiocephalus argus C.in China

    GUO Qionglin; JIA Weizhang; HAN Xianpu; CAI Taozhen; GONG Xiaoning; SUN Xiaofeng

    2004-01-01

    From 2001 to 2002,a new and emergent infectious disease of Ophiocephalus argus occurred in a fishery in Hubei Province,China,with an incidence of 60%~70% and a mortality as high as 100%.The diseased fish showed an enlarged abdomen,the millet-like nodules in internal organs,and the swollen kidney which was composed of 5~10 sarcoma-like bodies in cream or gray-white colour or ulcerated into beandregs-like substance.Light microscopic observation revealed the basophilic or acidphilic inclusions in cytoplasm of the cells and the granulomas,a diffusive chronic inflammation in internal organs.Further analysis under an electron microscope indicated that the intracytoplasmic inclusions were rickettsia-like organisms (RLOs) that are either spherical or coccoid,with variable size,ranging from 0.5~1.5 μm in diameter,and enclosed within membrane-bound cytoplasmic vacuoles.RLO had a central nucleoid region with some fine filamentous structures and an electron-dense granule.Its cytoplasm contained abundant ribosomal bodies.Occasionally,RLO appeared to be divided by binary fission.RLOs were also observed in the homogenized tissue of infected fish.The results suggested that the death of cultured O.Argus was caused by RLO infection.

  5. INFECTION BY Rickettsia felis IN OPOSSUMS (Didelphis sp. FROM YUCATAN, MEXICO

    Gaspar PENICHE-LARA

    2016-01-01

    Full Text Available Rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the Americas. Its transmission cycle involves fleas as biological vectors (mainly Ctenocephalides felis and multiple domestic and synanthropic mammal hosts. Nonetheless, the role of mammals in the cycle of R. felis is not well understood and many efforts are ongoing in different countries of America to clarify it. The present study describes for the first time in Mexico the infection of two species of opossum (Didelphis virginiana and D. marsupialis by R. felis. A diagnosis was carried out from blood samples by molecular methods through the gltAand 17 kDa genes and sequence determination. Eighty-seven opossum samples were analyzed and 28 were found to be infected (32.1% from five out of the six studied localities of Yucatan. These findings enable recognition of the potential epidemiological implications for public health of the presence of infected synanthropic Didelphis in households.

  6. INFECTION BY Rickettsia felis IN OPOSSUMS (Didelphis sp.) FROM YUCATAN, MEXICO

    PENICHE-LARA, Gaspar; RUIZ-PIÑA, Hugo A.; REYES-NOVELO, Enrique; DZUL-ROSADO, Karla; ZAVALA-CASTRO, Jorge

    2016-01-01

    Rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the Americas. Its transmission cycle involves fleas as biological vectors (mainly Ctenocephalides felis) and multiple domestic and synanthropic mammal hosts. Nonetheless, the role of mammals in the cycle of R. felis is not well understood and many efforts are ongoing in different countries of America to clarify it. The present study describes for the first time in Mexico the infection of two species of opossum (Didelphis virginiana and D. marsupialis) by R. felis. A diagnosis was carried out from blood samples by molecular methods through the gltAand 17 kDa genes and sequence determination. Eighty-seven opossum samples were analyzed and 28 were found to be infected (32.1%) from five out of the six studied localities of Yucatan. These findings enable recognition of the potential epidemiological implications for public health of the presence of infected synanthropic Didelphis in households. PMID:27074326

  7. Molecular evidence of Ehrlichia canis and Rickettsia massiliae in ixodid ticks of carnivores from South Hungary.

    Hornok, Sándor; Fuente, José; Horváth, Gábor; Fernández de Mera, Isabel G; Wijnveld, Michiel; Tánczos, Balázs; Farkas, Róbert; Jongejan, Frans

    2013-03-01

    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

  8. INFECTION BY Rickettsia felis IN OPOSSUMS (Didelphis sp.) FROM YUCATAN, MEXICO.

    Peniche-Lara, Gaspar; Ruiz-Piña, Hugo A; Reyes-Novelo, Enrique; Dzul-Rosado, Karla; Zavala-Castro, Jorge

    2016-01-01

    Rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the Americas. Its transmission cycle involves fleas as biological vectors (mainly Ctenocephalides felis) and multiple domestic and synanthropic mammal hosts. Nonetheless, the role of mammals in the cycle of R. felis is not well understood and many efforts are ongoing in different countries of America to clarify it. The present study describes for the first time in Mexico the infection of two species of opossum (Didelphis virginiana and D. marsupialis) by R. felis. A diagnosis was carried out from blood samples by molecular methods through the gltA and 17 kDa genes and sequence determination. Eighty-seven opossum samples were analyzed and 28 were found to be infected (32.1%) from five out of the six studied localities of Yucatan. These findings enable recognition of the potential epidemiological implications for public health of the presence of infected synanthropic Didelphis in households. PMID:27074326

  9. Prevalence and infection load dynamics of Rickettsia felis in actively feeding cat fleas.

    Kathryn E Reif

    Full Text Available BACKGROUND: Rickettsia felis is a flea-associated rickettsial pathogen recurrently identified in both colonized and wild-caught cat fleas, Ctenocephalides felis. We hypothesized that within colonized fleas, the intimate relationship between R. felis and C. felis allows for the coordination of rickettsial replication and metabolically active periods during flea bloodmeal acquisition and oogenesis. METHODOLOGY/PRINCIPAL FINDINGS: A quantitative real-time PCR assay was developed to quantify R. felis in actively feeding R. felis-infected fleas. In three separate trials, fleas were allowed to feed on cats, and a mean of 3.9x10(6 R. felis 17-kDa gene copies was detected for each flea. A distinct R. felis infection pattern was not observed in fleas during nine consecutive days of bloodfeeding. However, an inverse correlation between the prevalence of R. felis-infection, which ranged from 96% in Trial 1 to 35% in Trial 3, and the R. felis-infection load in individual fleas was identified. Expression of R. felis-infection load as a ratio of R. felis/C. felis genes confirmed that fleas in Trial 3 had significantly greater rickettsial loads than those in Trial 1. CONCLUSION/SIGNIFICANCE: Examining rickettsial infection dynamics in the flea vector will further elucidate the intimate relationship between R. felis and C. felis, and facilitate a more accurate understanding of the ecology and epidemiology of R. felis transmission in nature.

  10. Solution structure of the cold-shock-like protein from Rickettsia rickettsii

    The solution structure of the cold-shock-like protein from R. rickettsii, the causative agent of Rocky Mountain spotted fever, is reported. Rocky Mountain spotted fever is caused by Rickettsia rickettsii infection. R. rickettsii can be transmitted to mammals, including humans, through the bite of an infected hard-bodied tick of the family Ixodidae. Since the R. rickettsii genome contains only one cold-shock-like protein and given the essential nature of cold-shock proteins in other bacteria, the structure of the cold-shock-like protein from R. rickettsii was investigated. With the exception of a short α-helix found between β-strands 3 and 4, the solution structure of the R. rickettsii cold-shock-like protein has the typical Greek-key five-stranded β-barrel structure found in most cold-shock domains. Additionally, the R. rickettsii cold-shock-like protein, with a ΔG of unfolding of 18.4 kJ mol−1, has a similar stability when compared with other bacterial cold-shock proteins

  11. Introduction to the alpha-proteobacteria: Wolbachia and Bartonella, Rickettsia, Brucella, Ehrlichia, and Anaplasma.

    Bowman, Dwight D

    2011-11-01

    Wolbachia is an obligate intracellular endosymbiont and likely mutualist living within the heartworm Dirofilaria immitis and a number of other filarial nematodes in the family Onchocercidae. The bacterial infection is passed from worm to worm transovarially; the organisms are in ovarian cells, the developing microfilariae, and multiply and persist in all later developmental stages through the mosquito and into the next host. Besides being present in the ovaries of the adult worms, they also are present in large numbers within the hypodermal tissues of the nematode. It is now know that these bacteria that were first observed in heartworms more than 30 years ago are actually related to similar Wolbachia bacteria that are found in arthropods. Wolbachia is an alpha-proteobacteria, and this group includes a number of important arthropod-transmitted bacterial agents of dogs and cats: Rickettsia rickettsii, R. felis, Anaplasma platys, Ehrlichia canis, E. chaffeensis, and E. ewingii. Alpha-proteobacteria are also important as obligate intracellular mutualists in plants in which they are responsible for nitrogen fixation. Recent work on the treatment of heartworms in dogs with doxycycline stems from related work with the human filarial nematode Onchocerca volvulus that causes river blindness in people. PMID:22152604

  12. Comparative evaluation of Amblyomma ovale ticks infected and noninfected by Rickettsia sp. strain Atlantic rainforest, the agent of an emerging rickettsiosis in Brazil.

    Krawczak, Felipe S; Agostinho, Washington C; Polo, Gina; Moraes-Filho, Jonas; Labruna, Marcelo B

    2016-04-01

    In 2010, a novel spotted fever group rickettsiosis was reported in the Atlantic rainforest coast of Brazil. The etiological agent was identified as Rickettsia sp. strain Atlantic rainforest, and the tick Amblyomma ovale was incriminated as the presumed vector. The present study evaluated under laboratory conditions four colonies of A. ovale: two started from engorged females that were naturally infected by Rickettsia sp. strain Atlantic rainforest (designated as infected groups); the two others started from noninfected females (designated as control groups). All colonies were reared in parallel from F0 engorged female to F2 unfed nymphs. Tick-naïve vesper mice (Calomys callosus) or domestic rabbits were used for feeding of each tick stage. Rickettsia sp. strain Atlantic rainforest was preserved by transstadial maintenance and transovarial transmission in A. ovale ticks for at least 2 generations (from F0 females to F2 nymphs), because nearly 100% of the tested larvae, nymphs, and adults from the infected groups were shown by PCR to contain rickettsial DNA. All vesper mice and rabbits infested by larvae and nymphs, and 50% of the rabbits infested by adults from the infected groups seroconverted, indicating that these tick stages were vector competent for Rickettsia sp. strain Atlantic rainforest. Expressive differences in mortality rates and reproductive performance were observed between engorged females from the infected and control groups, as indicated by 75.0% and 97.1% oviposition success, respectively, and significantly lower egg mass weight, conversion efficiency index, and percentage of egg hatching for the infected groups. Our results indicate that A. ovale can act as a natural reservoir for Rickettsia sp. strain Atlantic rainforest. However, due to deleterious effect caused by this rickettsial agent on engorged females, amplifier vertebrate hosts might be necessary for persistent perpetuation of Rickettsia sp. strain Atlantic rainforest in A. ovale under

  13. Detección de Rickettsia spp. en Garrapatas de Myrmecophaga tridactyla de Vida Libre en la Sabana Inundable de Casanare‚ Colombia -resumen-

    César Rojano-Bolaño; R Ávila-Avilán; L Miranda-Cortés; V Contreras-Cogollo; Jorge Miranda-Regino; Laura Hernández-Fernández; Salim Mattar-Velilla; Santiago Monsalve-Buriticá; J Carrascal-Velásquez

    2014-01-01

    Las bacterias del género Rickettsia son organismos con distribución mundial‚ causantes de algunas enfermedades zoonóticas de gran importancia en salud pública. Sin embargo‚ en Colombia son pocos los estudios enfocados a conocer su distribución y los vectores involucrados. El objetivo de este estudio fue detectar la presencia de Rickettsia spp.‚ en garrapatas colectadas en nueve osos palmeros (Myrmecophaga tridactyla) de vida libre en el municipio de Pore‚ Casanare‚ entre los años 2013 y 2014....

  14. Molecular evidence for the presence of Rickettsia Felis in the feces of wild-living African apes.

    Alpha Kabinet Keita

    Full Text Available BACKGROUND: Rickettsia felis is a common emerging pathogen detected in mosquitoes in sub-Saharan Africa. We hypothesized that, as with malaria, great apes may be exposed to the infectious bite of infected mosquitoes and release R. felis DNA in their feces. METHODS: We conducted a study of 17 forest sites in Central Africa, testing 1,028 fecal samples from 313 chimpanzees, 430 gorillas and 285 bonobos. The presence of rickettsial DNA was investigated by specific quantitative real-time PCR. Positive results were confirmed by a second PCR using primers and a probe targeting a specific gene for R. felis. All positive samples were sequenced. RESULTS: Overall, 113 samples (11% were positive for the Rickettsia-specific gltA gene, including 25 (22% that were positive for R. felis. The citrate synthase (gltA sequence and outer membrane protein A (ompA sequence analysis indicated 99% identity at the nucleotide level to R. felis. The 88 other samples (78% were negative using R. felis-specific qPCR and were compatible with R. felis-like organisms. CONCLUSION: For the first time, we detected R. felis in wild-living ape feces. This non invasive detection of human pathogens in endangered species opens up new possibilities in the molecular epidemiology and evolutionary analysis of infectious diseases, beside HIV and malaria.

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

    The R. prowazekii 3-ketoacyl-(acyl-carrier-protein) reductase is similar to those from other prokaryotic pathogens but differs significantly from the mammalian orthologue, strengthening its case as a potential drug target. 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

  16. The role of cottontail rabbits (Sylvilagus spp.) in the ecology of Rickettsia rickettsii in the United States.

    Burgdorfer, W; Cooney, J C; Mavros, A J; Jellison, W L; Maser, C

    1980-07-01

    Rocky Mountain (Sylvilagus nuttallii) and eastern (S. floridanus) cottontails were examined for their susceptibility to virulent and avirulent strains of the spotted fever agent, Rickettsia rickettsii. Both species of rabbits responded to inoculation of yolk sac suspensions containing 500 egg LD50 of either virulent or avirulent rickettsiae, with rickettsemias detectable as early as 3 days after inoculation and lasting up to 7 days. When fed upon by infected ticks, only one of three Rocky Mountain and one of four eastern cottontails developed rickettsemias detectable in embryonated hens' eggs. Rickettsial concentrations in the peripheral blood fo Rocky Mountain cottontails, infected either by syringe or by bites of one or more Dermacentor andersoni ticks harboring virulent R. rickettsii, were sufficient to infect simultaneously feeding normal larvae of this tick species. However, infection rates wre low and did not exceed 11.7%. In a single experiment, the bites of D. variabilis, infected with an avirulent strain of R. rickettsii, did not produce rickettsemias sufficient to infect normal D. variabilis larvae. These laboratory findings suggest that cottontail rabbits, although susceptible to R. rickettsii, do not serve as efficient reservoirs for infecting ticks. PMID:7406116

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

    Fumarate hydratase is an enzyme of the tricarboxylic acid cycle, one of the metabolic pathways characteristic of the mitochondria. The structure of R. prowazekii class II fumarate hydratase is reported at 2.4 Å resolution and is compared with the available structure of the human homolog. 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

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

    Janecek Elisabeth

    2012-10-01

    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

  19. Evidence for proteolytic cleavage of the 120-kilodalton outer membrane protein of rickettsiae: identification of an avirulent mutant deficient in processing.

    Hackstadt, T; Messer, R; Cieplak, W; Peacock, M G

    1992-01-01

    The 120-kDa rickettsial outer membrane protein (rOmpB) is encoded by a gene with the capacity to encode a protein of approximately 168 kDa. The carboxy-terminal end of the molecule is apparently cleaved to yield 120- and 32-kDa products. Both polypeptides are surface exposed and remain associated with the outer membrane of intact rickettsiae. All species of rickettsiae examined display similar cleavage of rOmpB. Comparison of diverse species of rickettsiae demonstrate a conserved N terminus of the 32-kDa fragment, with a predicted procaryotic secretory signal peptide immediately upstream of the proposed cleavage site. Coprecipitation of the 120-kDa rOmpB protein and the 32-kDa peptide by monoclonal antibodies specific for the 120-kDa portion of the molecule suggests that the two fragments remain noncovalently associated on the surface of rickettsiae. Analysis of an avirulent mutant of Rickettsia rickettsii revealed reduced amounts of the 120- and 32-kDa fragments, but with a correspondingly larger rOmpB protein that displayed properties expected of the putative precursor. This avirulent mutant grows intracellularly but fails to cause the lysis of infected cells that is typical of R. rickettsii. DNA sequence analysis of the region of the gene encoding the cleavage site of the avirulent strain revealed no difference from the sequence obtained from virulent R. rickettsii. The 168-kDa putative precursor of the avirulent strain of R. rickettsii was not extracted from the surface by dilute buffers, as is the 120-kDa protein of virulent R. rickettsii or R. prowazekii. These latter results suggest that the 32-kDa C-terminal region of the molecule may serve as a membrane anchor domain. Images PMID:1729180

  20. Survey of ticks (Acari: Ixodidae) and their rickettsia in an Atlantic rain forest reserve in the State of São Paulo, Brazil.

    Sabatini, Guilherme S; Pinter, Adriano; Nieri-Bastos, Fernanda A; Marcili, Arlei; Labruna, Marcelo B

    2010-09-01

    The current study investigated the occurrence of ticks and their rickettsiae in the Serra do Mar State Park, which encompasses one of the largest Atlantic rain forest reserves of Brazil. From July 2008 to June 2009, a total of 2439 ticks (2,196 free living and 243 collected on hosts) was collected, encompassing the following 13 species: Amblyomma aureolatum (Pallas), Amblyomma brasiliense AragAo, Amblyomma dubitatum Neumann, Amblyomma fuscum Neumann, Amblyomma incisum Neumann, Amblyomma longirostre (Koch), Amblyomma naponense (Packard), Amblyomma nodosum Neumann, Amblyomma ovale Koch, Haemaphysalis juxtakochi Cooley, Ixodes aragaoi Fonseca, Ixodes loricatus Neumann, and Rhipicephalus sanguineus (Latreille). Ticks were submitted to polymerase chain reaction assays targeting portions of the rickettsial genes gltA and ompA. Polymerase chain reaction products were DNA sequenced and compared with corresponding sequences available in GenBank. Rickettsia bellii, a rickettsia of unknown pathogenicity, was detected in one A. aureolatum, one A. ovale, and three A. incisum specimens. At least 8.8% (3/34) of the free-living A. ovale ticks, 13.6% (8/59) of the A. ovale ticks collected from dogs, and 1.9% (1/54) of the R. sanguineus (Latreille) ticks were found to be infected by Rickettsia sp strain Atlantic rain forest, a novel strain that has been shown to cause an eschar-associated spotted fever in the state of Sho Paulo. Our results suggest that A. ovale is the vector of Rickettsia sp strain Atlantic rain forest in the state of São Paulo. PMID:20939390

  1. Analysis of the Gut Microbes of the Chinese White Wax Scale Ericerus pela and Molecular Detection of Rickettsia%白蜡虫肠道微生物分析及立克次氏体分子检测

    徐冬丽; 刘魏魏; 胡艳红; 杨璞; 陈晓鸣

    2012-01-01

    To understand the diversity of the gut microbes of Chinese white wax scale Ericerus pela, 16S rDNA clone library was constructed to analyze the gut microbes of the female E. pela adults. The results showed that, the gut of E. pela contained abundant of Rickettsia. Gut microbes Arsenophonus and Variovorax were also been identified. And Rickettsia was the main bacteria in gut of E. pela. The phylogenetic analysis of the 16S rDNA showed that, the Rickettsia from E. pela has close relationship with that of pea aphid Acyrthosiphon pisum. PCR amplification was performed using the specific primers for Rickettsia to detect infection in 30 male and 30 female individuals. The result showed that, the infected male and female were 24 and 12 respectively.

  2. A rickettsia-like organism from Ixodes uriae ticks collected on the Kerguelen Islands (French Subantarctic Territories).

    Chastel, C; Demazure, M; Chastel, O; Genevois, F; Legrand, M C; Grulet, O; Odermatt, M; Le Goff, F

    1993-02-01

    A rickettsia-like microorganism was isolated in suckling mice from Ixodes uriae ticks collected from penguins breeding on Mayes Island, Kerguelen Archipelago, French Subantarctic Territories. At isolation, this agent mimicked a tick-borne arbovirus. Finally, electron microscopy studies of infected suckling mouse livers showed the presence of inclusions filled with pleomorphic microorganism in the cytoplasm of some hepatocytes, sometimes dividing by binary fission and thus of obviously non-viral nature. No firm serological relationship was demonstrated with Chlamydia psittaci, C. trachomatis, C. pneumoniae, Coxiella burnetti, Cowdria ruminentium, Ehrlichia canis, E. phagocytophila, E. risticii or the WSU/1044 agent. The exact taxonomic position of the "Mayes" agent remains to be clarified. PMID:8105647

  3. Serosurvey for tick-borne diseases in dogs from the Eastern Amazon, Brazil Pesquisa Sorológica por doenças transmitidas por carrapatos em cães da Amazônia oriental, Brasil

    Mariana Granziera Spolidorio

    Full Text Available Canine ehrlichiosis and babesiosis are the most prevalent tick-borne diseases in Brazilian dogs. Few studies have focused attention in surveying tick-borne diseases in the Brazilian Amazon region. A total of 129 blood samples were collected from dogs living in the Brazilian eastern Amazon. Seventy-two samples from dogs from rural areas of 19 municipalities and 57 samples from urban stray dogs from Santarém municipality were collected. Serum samples were submitted to Indirect Immunofluorescence Assay (IFA with antigens of Babesia canis vogeli, Ehrlichia canis, and six Rickettsia species. The frequency of dogs containing anti-B. canis vogeli, anti-E. canis, and anti-Rickettsia spp. antibodies was 42.6%, 16.2%, and 31.7%, respectively. Anti-B. canis vogeli antibodies were detected in 59.6% of the urban dogs, and in 29.1% of the rural dogs (P Ehrliquiose canina e babesiose canina são as doenças parasitárias transmitidas por carrapatos de maior prevalência em cães do Brasil. Poucos estudos pesquisaram doenças transmitidas por carrapatos na região da Amazônia brasileira. Um total de 129 amostras de sangue foram colhidas de cães da Amazônia oriental brasileira. Setenta e dois cães eram de áreas rurais de 19 municípios do Estado do Pará, e 57 amostras foram colhidas de cães errantes vadios da área urbana do município de Santarém-PA. As amostras de soro foram submetidas ao ensaio de imunofluorescência indireta, com antígenos de Babesia canis vogeli, Ehrlichia canis, e seis espécies de Rickettsia. A frequência de cães com anticorpos anti-B. canis vogeli, anti-E. canis, e anti-Rickettsia spp. foi de 42,6%, 16,2% e 31,7%, respectivamente. Anticorpos anti-B. canis vogeli foram detectados em 59,6% dos cães urbanos, e em 29,1% dos cães rurais (P < 0.05. Para E. canis, a soroprevalência foi parecida entre os cães urbanos (15,7% e rurais (16,6%. Para Rickettsia spp., cães rurais apresentaram prevalência (P < 0.05 significativamente

  4. Absence of zoonotic Bartonella species in questing ticks: First detection of Bartonella clarridgeiae and Rickettsia felis in cat fleas in the Netherlands

    Reimerink Johan R

    2011-04-01

    Full Text Available Abstract Background Awareness for flea- and tick-borne infections has grown in recent years and the range of microorganisms associated with these ectoparasites is rising. Bartonella henselae, the causative agent of Cat Scratch Disease, and other Bartonella species have been reported in fleas and ticks. The role of Ixodes ricinus ticks in the natural cycle of Bartonella spp. and the transmission of these bacteria to humans is unclear. Rickettsia spp. have also been reported from as well ticks as also from fleas. However, to date no flea-borne Rickettsia spp. were reported from the Netherlands. Here, the presence of Bartonellaceae and Rickettsiae in ectoparasites was investigated using molecular detection and identification on part of the gltA- and 16S rRNA-genes. Results The zoonotic Bartonella clarridgeiae and Rickettsia felis were detected for the first time in Dutch cat fleas. B. henselae was found in cat fleas and B. schoenbuchensis in ticks and keds feeding on deer. Two Bartonella species, previously identified in rodents, were found in wild mice and their fleas. However, none of these microorganisms were found in 1719 questing Ixodes ricinus ticks. Notably, the gltA gene amplified from DNA lysates of approximately 10% of the questing nymph and adult ticks was similar to that of an uncultured Bartonella-related species found in other hard tick species. The gltA gene of this Bartonella-related species was also detected in questing larvae for which a 16S rRNA gene PCR also tested positive for "Candidatus Midichloria mitochondrii". The gltA-gene of the Bartonella-related species found in I. ricinus may therefore be from this endosymbiont. Conclusions We conclude that the risk of acquiring Cat Scratch Disease or a related bartonellosis from questing ticks in the Netherlands is negligible. On the other hand fleas and deer keds are probable vectors for associated Bartonella species between animals and might also transmit Bartonella spp. to humans.

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

    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)

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

    Pan Lei

    2012-10-01

    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 μL 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

  7. Miocarditis por dengue

    Ricardo Amador García Hernández; Fidel Espinosa Rivera; Lianet Rivero Seriel

    2013-01-01

    El dengue es un arbovirus transmitido por el Aedes aegypti, produce los cuadros clínicos de dengue clásico, dengue hemorrágico y síndrome de choque por dengue, aisladamente se reportan casos de miocarditis. Se presentó un paciente con antecedentes de dengue clásico que manifestó dolor precordial asociado a cambios electrocardiográficos y fue ingresado en este hospital por síndrome coronario agudo probable, al cual se le diagnosticó clínicamente miocarditis por dengue.

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

    Mahling Monia

    2011-07-01

    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

  9. DETECTION OF RICKETTSIA FELIS LIKE AGENT FROM EULAELAPS STABULARIS KOCH%从厩真厉螨中检出与猫立克次体近缘的立克次体核酸片段

    姚李四; 刘勇先; 邵丽筠; 张晓龙; 杨宇; 王静; 徐宝梁; 王宝麟; 赵彤言

    2012-01-01

    本研究用立克次体属特异的gltA和ompB基因扩增引物,从吉林长白县捕获鼠中分拣的534只厩真厉螨中扩得gltA和ompB基因片段.通过基因片段的序列测定、BLAST比对和系统发育分析,显示两个扩增基因与猫立克次体Rickettsia felis同源性最高(99%),证明该地区厩真厉螨携带与猫立克次体近缘的立克次体.%The segments of glt A gene and omp B gene were amplified and identified with Rickettsia specific git A and omp B primers from 534 mites (Eulaelaps stabularis Koch) collected from rodents of Changbai County, Jilin Province, China. By sequencing, BLAST qualifying and phylogenetic analyzing, it was revealed that the two amplified segments were of highest homology to Rickettsia fells (99% ) , implying that the locally collected E. Stabularis may carry some Rickettsia sp. Allied to Rickettsia fells.

  10. Prevalence of antibodies to Rickettsia conorii in human beings and dogs from Catalonia: a 20-year perspective.

    Espejo, E; Andrés, M; Pérez, J; Prat, J; Guerrero, C; Muñoz, M T; Alegre, M D; Lite, J; Bella, F

    2016-07-01

    The incidence of Mediterranean spotted fever (MSF) in Catalonia (Spain) has decreased in the last two decades. The prevalence of antibodies to Rickettsia conorii in human beings and dogs in the region of Vallès Occidental (Catalonia) was assessed by indirect immunofluorescence, and the results compared with those obtained in a similar study from 1987. Nineteen (5·0%) out of 383 human serum samples had antibodies to R. conorii. This seroprevalence was significantly lower (11·5%) (P = 0·003) than that recorded in the 1987 survey. Forty-two out (42·0%) of 100 canine serum samples had antibodies to R. conorii. A high proportion of the studied dogs (91·0%) were receiving anti-tick treatment, mainly with permethrin-imidacloprid spot-on (Advantix, Bayer, Germany). The current canine seroprevalence was not significantly different from that recorded in the 1987 survey (36.9%). In conclusion, this study shows a significant decrease in the prevalence of antibodies to R. conorii in the human population of Catalonia in the last 20 years, which corresponds with a decrease in the number of cases of MSF. We suggest that the widespread use of anti-tick treatment in dogs could limit the introduction of ticks to humans due to a reduction of infestation duration in dogs, thus contributing to the decrease in MSF incidence. PMID:26899636

  11. Dose-response model of murine typhus (Rickettsia typhi: time post inoculation and host age dependency analysis

    Tamrakar Sushil B

    2012-03-01

    Full Text Available Abstract Background Rickettsia typhi (R. mooseri is the causative agent of murine typhus. It is one of the most widely distributed flea-borne diseases with a relatively mild febrile initial illness with six to 14 days of incubation period. The bacterium is gram negative and an obligate intracellular pathogen. The disease is transmitted to humans and vertebrate host through fleabites or via contact with infected feces. This paper develops dose-response models of different routes of exposure for typhus in rodents. Methods Data from published articles were analyzed using parametric dose-response relationship models. Dose-response relationships were fit to data using the method of maximum likelihood estimation (MLE. Results Dose-response models quantifying the effects of different ages of rats and time post inoculation in BALB/c mice were analyzed in the study. Both the adult rats (inoculated intradermally and newborn rats (inoculated subcutaneously were best fit by exponential models and both distributions could be described by a single dose-response relationship. The BALB/C mice inoculated subcutaneously were best fit by Beta-Poisson models. The time post inoculation analysis showed that there was a definite time and response relationship existed in this case. Conclusions Intradermally or subcutaneously inoculated rats (adult and newborn models suggest that less than 1 plaque-forming unit (PFU (1.33 to 0.38 in 95% confidence limits of the pathogen is enough to seroconvert 50% of the exposed population on average. For the BALB/c mouse time post inoculation model, an average dose of 0.28 plaque-forming units (PFU (0.75 to 0.11 in 95% confidence limits will seroconvert 50% of the exposed mice.

  12. Detection of a Hepatozoon and spotted fever group Rickettsia species in the common marsupial tick (Ixodes tasmani) collected from wild Tasmanian devils (Sarcophilus harrisii), Tasmania.

    Vilcins, Inger-Marie E; Old, Julie M; Deane, Elizabeth

    2009-05-26

    Tasmanian devils are the largest extant marsupial carnivores, confined to the Australian island state of Tasmania. The iconic marsupial has dramatically declined in number since the discovery of devil facial tumor disease in 1996 and efforts are being made to uncover vital information to assist in the long-term survival of the species. Ticks are the main vectors of arthropod-borne disease in animals, raising the question of whether Tasmanian devils may be host to arthropods capable of harboring infectious agents. Partially engorged ticks were collected from 35 wild Tasmanian devils and tested for the presence of a range of tick-borne genera. A spotted fever group Rickettsia was detected in 45.5% of samples of the tick Ixodes tasmani (n=44), from all trapping locations, sharing close sequence identity to members of the Rickettsia massiliae group. A Hepatozoon species was also identified in 34.1% of the same sample set, sharing sequence similarities to Hepatozoon felis, a known pathogen of felids. Dual detection was identified in 13.6% of tick samples, where prevalence of the two genera overlapped. The existence of two previously undetected species of genera known for containing pathogens identifies additional potential risks to the health of the devil population. PMID:19303711

  13. Osteomielitis por salmonella

    Alicia Velázquez Pérez

    2014-08-01

    Full Text Available Se presenta el caso de una paciente femenina de color blanco y dos años de edad, con diagnóstico prenatal de sicklemia, que desde edades tempranas tiene problemas de la enfermedad. Ingresó en esta ocasión por una de las complicaciones infecciosas que ocasiona este padecimiento, una osteomielitis del húmero izquierdo, aislándose el germen en el hemocultivo realizado, una salmonella. Necesitó de tratamiento enérgico y prolongado; se obtuvo un resultado satisfactorio en la evolución de la enfermedad y se sigue sistemáticamente por consulta externa en la actualidad

  14. tirados por tractores

    Ciro E. Iglesias Coronel

    2006-01-01

    Full Text Available En el presente trabajo se brinda la metodología de realización y evaluación de los principales indicadores energéticos de los agregados de transporte agrícola, formados por tractores y remolques con el uso de la tensometría como herramienta para la toma de los datos experimentales de campo.

  15. Miotoxicidade por organofosforados

    Cavaliere Maria J.

    1996-01-01

    Full Text Available Os organofosforados são um grupo de compostos químicos amplamente utilizados em agropecuária como inseticidas, ocasionando intoxicações acidentais em animais e humanos, e mesmo sendo utilizados em tentativas de suicídio. A toxicidade desses produtos decorre sobretudo de insuficiência cárdio-respiratória por compromentimento do sistema nervoso autônomo. Sabe-se que alguns destes compostos induzem em animais de experimentação e em humanos, uma miopatia caracterizada por degeneração de células musculares, comprometendo sobretudo a musculatura respiratória. Baseado no fato de que este comprometimento contribui para a piora da função respiratória, propõe-se um protocolo de avaliação rotineira de miotoxicidade por compostos organofosforados, através de uma bateria mínima e suficiente de colorações e reações histoquímicas para quantificação da necrose muscular. Utilizaram-se como modelo experimental, grupos de ratos albinos (Wistar intoxicados com o organofosforado paraoxon, com e sem antídotos (atropina ou pralidoxima. Verificou-se nos grupos tratados com paraoxon e paraoxon mais atropina, necrose de fibras musculares no diafragma, que atingia em determinadas áreas até 15% das fibras. No grupo tratado com paraoxon mais pralidoxima, a necrose foi mínima, evidenciando o papel mioprotetor deste último antídoto.

  16. Por mil devaluados pesos

    Annie Rodríguez Collázos

    2013-03-01

    Full Text Available El estudio de lo popular y lo urbano hasta ahora se ha centrado en el comportamiento y en algunas relaciones de los habitantes con su entorno. “Por mil devaluados pesos. Publicidad popular y urbana”, pretende explorar las formas de publicidad, dispersas en diferentes espacios populares y urbanos en Bogotá, identificando esquemas y formas características de sus propios códigos comunicativos; se centran en un objeto de estudio consistente en las estrategias publicitarias y los códigos comunicativos en los mensajes publicitarios populares en las subculturas de San Victorino, 7 de Agosto y Sanandresito de San José.

  17. Nucleotomia por laser

    Cabral, oão José Lobato Guimarães Ferreira

    2009-01-01

    A hérnia de disco intervertebral com compressão nervosa que não cede ao tratamento médico, tradicionalmente, é indicação para tratamento cirúrgico. No entanto, técnicas minimamente invasivas e os procedimentos percutâneos têm sido usados e desenvolvidos nas últimas duas décadas, tanto como procedimentos alternativos, bem como possibilidades terapêuticas que antecedem o tratamento cirúrgico convencional, podendo adiar o mesmo por tempo indeterminado. De entre estas opções técnicas, surge a Nuc...

  18. Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

    This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage

  19. Ojo por ojo

    Ramón del Llano Ibáñez

    2011-12-01

    Full Text Available Nuestro pan y café de la mañana se acompaña de noticias alrededor de ejecuciones, de fosas clandestinas, de batallas del ejército, de balaceras en las calles y civiles caídos por balas perdidas : la muerte acompaña nuestro desayuno. Las calaveras de azúcar del día de muertos hoy son calaveras reales y amargas : 40 000 muertos en cuatro años después que el Presidente Calderón declaró la guerra a los narcotraficantes. Se han apresado a varios e importantes miembros de los cárteles : pero han si...

  20. Ojo por ojo

    Ramón del Llano Ibáñez

    2011-01-01

    Nuestro pan y café de la mañana se acompaña de noticias alrededor de ejecuciones, de fosas clandestinas, de batallas del ejército, de balaceras en las calles y civiles caídos por balas perdidas : la muerte acompaña nuestro desayuno. Las calaveras de azúcar del día de muertos hoy son calaveras reales y amargas : 40 000 muertos en cuatro años después que el Presidente Calderón declaró la guerra a los narcotraficantes. Se han apresado a varios e importantes miembros de los cárteles : pero han si...

  1. A vida por segundos

    Silva, Pedro Miguel Paiva da

    2010-01-01

    A Enfermagem regista evolução a vários níveis, o que torna imperioso reconhecer como de significativo valor o papel do enfermeiro. A Especialização em Enfermagem Médico-Cirúrgica visa o desenvolvimento de competências para a assistência de Enfermagem avançada ao doente adulto e idoso em estado crítico, revelando uma maior apropriação, por parte dos enfermeiros especialistas de uma concepção de cuidados sustentada numa conceptualização científica dos cuidados, daí infere-se o contributo num...

  2. Onicomicosis por hongos fuliginosos

    Ingrid Salas-Campos

    2009-12-01

    Full Text Available Justificación y objetivo: Las infecciones de las uñas producidas por hongos son un problema de frecuente consulta dermatológica. Los dermatofitos son la mayor causa de estas infecciones, siendo Trichophyton rubrum el agente etiológico más importante. Sin embargo, los hongos no dermatofitos, tanto hialinos como fuliginosos, pueden ser también responsables de estos cuadros clínicos. Debido a que estos hongos tienden a ser resistentes a los antimicóticos comúnmente usados para tratar las onicomicosis, es que se hace indispensable que el clínico se asegure por medio de un examen de laboratorio de la etiología de la infección. Métodos: Se estudiaron tres casos de pacientes con lesiones en uñas, que acudieron al laboratorio de Micología Médica, Facultad de Microbiología, Universidad de Costa Rica. Se realizaron los análisis de rutina para aislamiento e identificación de hongos patógenos. Resultados: En los tres casos estudiados se observó al examen directo micelio fuliginoso. En uno de los casos se aisló e identificó Scytalidium dimidiatum, hongo que presenta resistencia a los antifúngicos utilizados para tratar onicomicosis. Conclusión. El reporte de hongos diferentes a los dermatofitos como agentes etiológicos de onicomicosis es importante para que el médico pueda elegir el tratamiento más recomendado para este tipo de infección.

  3. Study of the Five Rickettsia prowazekii Proteins Annotated as ATP/ADP Translocases (Tlc): Only Tlc1 Transports ATP/ADP, While Tlc4 and Tlc5 Transport Other Ribonucleotides

    Audia, Jonathon P.; Winkler, Herbert H.

    2006-01-01

    The obligate intracytoplasmic pathogen Rickettsia prowazekii relies on the transport of many essential compounds from the cytoplasm of the eukaryotic host cell in lieu of de novo synthesis, an evolutionary outcome undoubtedly linked to obligatory growth in this metabolite-replete niche. The paradigm for the study of rickettsial transport systems is the ATP/ADP translocase Tlc1, which exchanges bacterial ADP for host cell ATP as a source of energy, rather than as a source of adenylate. Interes...

  4. Sociedad por Acciones Simplificada

    Carlos Andrés Arcila Salazar

    2009-07-01

    Full Text Available En Colombia, aspectos como la responsabilidad limitada; supresión de la llamada doctrina de ultra vires; duración ilimitada; eliminación de la regla, una acción, un voto; remedios al abuso de los derechos; posibilidad de eliminar prohibiciones a los administradores, libertad de establecer restricciones para la transferencia de acciones y la simplificación de los procedimientos de fusión; son inviables bajo nuestra legislación. Sin embargo, la Ley 1258 de 2008, ha incorporado al derecho societario colombiano un nuevo tipo societario híbrido, llamado “Sociedad por Acciones Simplificada”. Esta forma societaria híbrida se basa en un principio básico: garantizar amplia libertad a los empresarios en la estructuración de sus relaciones a través de disposiciones contractuales. La S.A.S. provee a los empresarios significativa flexibilidad contractual, a la vez que preserva beneficios como la limitación de la responsabilidad.

  5. Sociedad por Acciones Simplificada

    Carlos Andrés Arcila Salazar

    2009-06-01

    Full Text Available En Colombia, aspectos como la responsabilidad limitada; supresión de la llamada doctrina de ultra vires; duración ilimitada; eliminación de la regla, una acción, un voto; remedios al abuso de los derechos; posibilidad de eliminar prohibiciones a los administradores, libertad de establecer restricciones para la transferencia de acciones y la simplificación de los procedimientos de fusión; son inviables bajo nuestra legislación. Sin embargo, la Ley 1258 de 2008, ha incorporado al derecho societario colombiano un nuevo tipo societario híbrido, llamado “Sociedad por Acciones Simplificada”. Esta forma societaria híbrida se basa en un principio básico: garantizar amplia libertad a los empresarios en la estructuración de sus relaciones a través de disposiciones contractuales. La S.A.S. provee a los empresarios significativa flexibilidad contractual, a la vez que preserva beneficios como la limitación de la responsabilidad.

  6. Respuesta de las neuronas sensitivas al estrés genotóxico inducido por radiaciones ionizantes y por la inhibición del proteasoma

    Palanca Cuñado, Ana Rosa

    2014-01-01

    RESUMEN: Las neuronas son muy vulnerables al estrés genotóxico. Esta vulnerabilidad es particularmente relevante en las neuronas ganglionares sensitivas (NGS) dado que los ganglios carecen de barrera hematoencefálica que impida el acceso de agentes genotóxicos, como determinados fármacos utilizados en la quimioterapia del cáncer. Tales agentes producen un efecto neurotóxico que se traduce en neuropatías periféricas. Nuestro estudio analiza las bases celulares de la neurotoxicidad en las NGS e...

  7. 唐山地区蜱传斑点热群立克次体分子流行病学%Molecular epidemiological of spotted fever group Rickettsia from ticks in Tangshan area

    邹亚学; 贾青辉; 刘朋朋; 刘全; 高宏伟; 陈丽凤

    2011-01-01

    Two sets of specific primers,designed according to 16SrRNA for tick and the OmpA gene specific for spotted fever group Rickettsia(SFGR),were used to amplify 16SrRNA and OmpA gene from DNA samples extracted from Haemaphysalis longicornis in Tangshan area.The positive samples were sequenced and genetically analyzed by establishment of phylogenetic tree.Of 315 samples,25 samples were positive for SFGR and the infection rate reached to 7.94%.Phylogenetic analysis based on nucleotide sequence revealed that all positive strains were related and clustered together with Rickettsia sp.Japanese strain(93.30%),Rickettsia sp.Fujian strain(92.11%),Rickettsia sp.suifen strain(90.45%) and Rickettsia sp.Hulin strain(90.42%).The infection of spotted fever group Rickettsia in Tangshan area was serious,and the bacterium may be a novel species.%根据已发表的长角血蜱16SrRNA序列及斑点热群立克次体外膜蛋白A(OmpA)基因序列设计2对特异性引物,对唐山地区采集的长角血蜱进行PCR检测,并对阳性样本进行测序和序列分析,抽检样本建立分子系统进化树。结果表明,在315份蜱DNA样本中检测出25份阳性样本,阳性率为7.94%;序列分析结果显示唐山地区长角血蜱携带立克次体同处于一个分支,与日本株立克次体同源性最高(93.30%),其次是福建株立克次体(92.11%),黑龙江立克次体绥芬株(90.45%)、虎林株(90.42%)。结论得出唐山地区蜱传斑点热感染较严重,分子进化分析结果显示唐山地区蜱传斑点热群立克次体可能为一新种。

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

    Elizângela Guedes

    2005-12-01

    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.

  9. [BRILL-ZINSER DISEASE AS A CONSEQUENCE OF RICKETTSIA PROWAZEKII PERSISTENCE IN PREVIOUSLY ILL WHO HAVE HAD EPIDEMIC TYPHUS (EPIDEMIOLOGIC ASPECTS)].

    Tarasevich, I V; Shpynov, S N; Pantyukhina, A N

    2015-01-01

    Materials, that summarize data of original research and scientific literature on epidemiology and problems of persistence during epidemic typhus, whose causative agent (Rickettsia prowazekii) is reactivated in the organism of the previously ill and is manifested as Brill-Zinser disease, are presented. A retrospective analysis was carried out with the data obtained by Russian (All-Union) Centre for Rickettsioses during study of epidemiologic examination maps of 5705 typhus nidi and results of 19 463 blood sera analysis during study of immunologic structure of population in the territories of the former USSR for the period from 1970 to 1992. A decrease of epidemic typhus morbidity and an increase of the fraction of Brill-Zinser disease took place as a result of pediculosis corporis control. In separate territories specific weight of Brill-Zinser disease was 48% in 1952, up to 80% in 1969, and from 1977 all the ill were previously ill. However, during the perestroika period and afterwards, due to a reduction of economic and hygienic living conditions, appearance of refugees, the immune structure regarding typhus began to change. Due to the buildup of the population migration process and the presence of risk groups (refugees, homeless) among population of regions, where local wars are waged, the enhancement of methods of epidemic typhus and Brill-Zinser disease diagnostics and pediculosis corporis eradication is necessary. Study of R. prowazekii by molecular-genetics methods is necessary for complete understanding of its mechanism of persistence. PMID:26470431

  10. Nuevos casos de Linfogranulomatosis Micosica encontrados en Lima

    Pedro Weiss

    1948-12-01

    Full Text Available 1. Se presenta el estudio de cuatro casos peruanos de Micosis ganglionar causados por el Paracoccidioides brasilensis (Almeida. 2. La enfermedad debe ser frecuente en la selva peruana, se sugiere que se le tenga presente en los casos sospechosos de enfermedad de Hodgkin , tuberculosis ganglionares o amigdalianas, tumores hepáticos, pancreáticos, esplénicos y cerebrales, enfermedades todas que pueden ser simuladas por el Paracoccidiodes bresilensis y otras blastomicosis tropicales.

  11. The detection of spotted fever group Rickettsia DNA from fever patients in Dali, Yunnan%云南省大理州发热患者血液中检测斑点热群立克次体

    亚红祥; 王静林

    2012-01-01

    目的 调查云南省大理州不明原因发热患者是否存在斑点热.方法 用巢式-聚合酶链反应法扩增患者血液中的立克次体属groEL基因,并进行核酸序列鉴定和分析.结果 20例患者血液中检出1例立克次体核酸阳性(检出率5%),其序列分析与GenBank中Rickcttsia rickcttsii Iowa、Rickcttsia peacockii Rustic、Rickcttsia sibirica等斑点热群立克次体株的同源性最高(为99%).结论 首次证实云南大理地区存在斑点热患者,医疗部门应加强对斑点热的诊断与鉴别.%Objective To identify the pathogen of patients with fever with unknown origin and determine whether they were infected with spotted fever group Rickettsia. Methods Nested polymerase chain reaction (nPCR) was conducted to amplify groEL gene of rickettsia from the blood samples of the patients, the nucleotide sequencing and identification were carried out. Results Rickettsial DNA was detected in 1 of the 20 patients (5% ). The groEL gene of the strain shared high homology (99%) with Rickcttsia rickcttsii Iowa, Rickcttsia peacockii Rustic and Rickettsia sibirica. Conclusion It was the first time to diagnose the patient with spotted fever in Dali, Yunnan province. It is necessary to enhance the differential diagnosis of spotted fever in local medical institutions.

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

    Alejandra Baéz

    2007-10-01

    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

  13. Miasis cutanea por cordylobia anthropophaga

    Alkorta Gurrutxaga Miriam; Beristain Rementeria Xabier; Cilla Eguiluz Gustavo; Tuneu Valls Anna; Zubizarreta Salvador José

    2001-01-01

    El incremento progresivo en el número de personas que viajan a países tropicales ha hecho que las enfermedades importadas adquieran una relevancia cada vez mayor. Las miasis (o infestaciones por larvas de moscas) cutáneas se encuentran entre este tipo de enfermedades siendo especialmente frecuentes en países tropicales. A propósito de la observación de un caso de miasis cutánea masiva por Cordylobia antropophaga, que ocurrió en una mujer de 34 años de edad al volver de un viaje a Senegal, se ...

  14. La Transversal Cafetera por Caldas

    Duque Escobar, Gonzalo

    2014-01-01

    Dada la necesidad de una transversal férrea para resolver las falencias estructurales del transporte de carga colombiano, con la construcción del nuevo Túnel Cumanday bimodal y doble cruzando la Cordillera Central por Caldas, la nueva Transversal Cafetera podría diseñarse con pendiente máxima del 6% y velocidad de 80 km/h, y convertirse en complemento al paso por la Línea, y en el soporte de un corredor logístico que integraría la región andina de Colombia, al detonar con el ferrocarril senda...

  15. Ptose palpebral causada por Paquidermoperiostose

    Patricia Regina de Pinho Tavares

    2014-08-01

    Full Text Available A paquidermoperiostose é uma síndrome caracterizada por acometimento cutâneo e ósseo, e em alguns casos ocorre comprometimento palpebral leve. É uma síndrome rara, idiopática ou hereditária, com provável herança autossômica dominante de penetrância variável. Descreve-se o caso de um paciente com ptose grave por paquidermoperiostose elucidando sua fisiopatologia e conduta cirúrgica aplicada.

  16. Se los por se lo

    José Luis Rivarola

    1985-01-01

    El sistema de la conjugación "objetiva" plantea interesantesproblemas que fueron tratados en parte por K. Heger (1966) en suestudio comparativo del francés y del español. De la comparaciónse desprende, por ejemplo, que en español hay un cierto número deambigüedades que no permiten establecer un "paradigma tan completo y unívoco" como en el caso del francés. Dentro de estas ambigüedades se encuentran las que propicia el gramema se: "El morfema [gramema] se funciona no sólo como pronombre refle...

  17. Diverticulitis yeyunal perforada por enterolito.

    Marenco De la Cuadra, Beatriz; Gomez-Rosado, Juan Carlos; Capitan-Morales, Luis-Cristobal; Valdés Hernández, Javier; Reyes-lopera, N.J. De los

    2012-01-01

    La diverticulosis yeyunal es una enfermedad adquirida rara. Casi el 60-70% keeps asymptomátic or Con síntomas crónicos inespecíficos, aunque puede presentarse como un abdomen agudo. La perforación debida a enterolitos es una causa extremadamente rara do complicación, y puede producirse por la impactación de ésta contra la pared intestinal. Presentamos caso de un varón de 82 años que acude a urgencias por un dolor súbito abdominal, difuso, con irritación peritoneal, leucocitosis con neutro...

  18. Serosurvey of Rickettsia spp. in dogs and humans from an endemic area for Brazilian spotted fever in the State of São Paulo, Brazil Sorologia para Rickettsia spp. em cães e humanos de uma área endêmica para febre maculosa brasileira no Estado de São Paulo, Brasil

    Adriano Pinter

    2008-02-01

    Full Text Available The present study provides a rickettsial serosurvey in 25 dogs and 35 humans in an endemic area for Brazilian spotted fever in the State of São Paulo, where the tick Amblyomma aureolatum is the main vector. Testing canine and human sera by indirect immunofluorescence against four Rickettsia antigens (R. rickettsii, R. parkeri, R. felis and R. bellii showed that 16 (64% of canine sera and 1 (2.8% of human sera reacted to at least one of these rickettsial antigens with titers ³ 64. Seven canine sera and the single reactive human serum showed titers to R. rickettsii at least four times those of any of the other three antigens. The antibody titers in these 7 animals and 1 human were attributed to stimulation by R. rickettsii infection. No positive canine or human serum was attributed to stimulation by R. parkeri, R. felis, or R. bellii. Our serological results showed that dogs are important sentinels for the presence of R. rickettsii in areas where the tick A. aureolatum is the main vector of Brazilian spotted fever.Este estudo avaliou a ocorrência de anticorpos anti-Rickettsia em 25 cães e 35 humanos, em uma área endêmica para a febre maculosa brasileira no Estado de São Paulo, onde o principal vetor é o carrapato Amblyomma aureolatum. Soros dos cães e humanos foram testados pela técnica de imunofluorescência indireta contra quatro antígenos de riquétsias (R. rickettsii, R. parkeri, R. felis, R. bellii, mostrando que soros de 16 (64% cães e 1 (2,8% humano reagiram com títulos ³ 64 para pelo menos um dos antígenos de riquétsias. Sete soros caninos e o único soro humano reativo demonstraram títulos para R. rickettsii no mínimo quatro vezes maior do que aqueles para os outros antígenos de riquétsias. Os títulos de anticorpos nesses cães e um humano foram considerados homólogos a R. rickettsii, enquanto que nenhum soro de cão ou humano foi considerado reativamente homólogo para R. parkeri, R. felis ou R. bellii. Os

  19. DESAJUSTE EDUCATIVO POR REGIONES EN COLOMBIA: ¿COMPETENCIA POR SALARIOS O POR PUESTOS DE TRABAJO?

    Maribel Castillo Caicedo

    2007-06-01

    Full Text Available Este trabajo aporta una perspectiva del fenómeno de la sobreeducación, entendida como un desajuste por exceso, entre el nivel educativo alcanzado por el individuo y el exigido por el puesto de trabajo en el cual se desempeña; esto se debe a que existe una demanda laboral estrecha de puestos de trabajo para personas calificadas en Colombia. Se analizan las contribuciones empíricas existentes y el debate sobre las mismas; se examinan las teorías que permiten explicar la existencia de un desajuste educativo y se realiza una revisión de la literatura internacional y nacional sobre el tema. Adicionalmente, se plantean una serie de hipótesis para desarrollar un esquema que permita determinar el comportamiento del individuo en el fenómeno de la sobreeducación.

  20. (phoenicopterus roseus por intoxicación aguda por plomo

    D Romero

    2007-01-01

    Full Text Available La presencia de plomo en el medio ambiente es un hecho indiscutible. Ello es objeto de gran interés sanitario pues repercute tanto en la salud de los animales como en la del ser humano. El plumbismo es una intoxicación que puede afectar a cualquier especie animal. En el ámbito de la fauna silvestre se asocia principalmente a la actividad cinegética en los humedales y a la ingestión de plomo metálico por parte de las aves que frecuentan estos ecosistemas. En España cada año mueren decenas de miles de aves acuáticas como consecuencia de la ingesta de perdigones de plomo. En los individuos capturados enfermos se pueden observar signos clínicos, mientras que a partir de muestras de cadáveres se obtienen datos sobre niveles tisulares de plomo. Sin embargo la evaluación de lesiones anatomopatológicas en animales de vida silvestre es difícil de realizar por la dificultad de encontrar animales recién muertos o afectados de un cuadro agudo mortal. La reproducción de esta patología en animales de experimentación se suele realizar en cisnes, palomas o patos, pero no en flamencos, por lo que no es usual disponer de datos histológicos en esta especie. En este trabajo presentamos la clínica, analítica y estudio microscópico de diferentes tejidos de un flamenco común (Phoenicopterus roseus muerto por plumbismo.

  1. Se los por se lo

    José Luis Rivarola

    1985-12-01

    Full Text Available El sistema de la conjugación "objetiva" plantea interesantesproblemas que fueron tratados en parte por K. Heger (1966 en suestudio comparativo del francés y del español. De la comparaciónse desprende, por ejemplo, que en español hay un cierto número deambigüedades que no permiten establecer un "paradigma tan completo y unívoco" como en el caso del francés. Dentro de estas ambigüedades se encuentran las que propicia el gramema se: "El morfema [gramema] se funciona no sólo como pronombre reflexivo, sinotambién como variante combinatoria del pronombre personal complemento indirecto de la tercera persona.

  2. Miasis cutanea por cordylobia anthropophaga

    Alkorta Gurrutxaga Miriam

    2001-01-01

    Full Text Available El incremento progresivo en el número de personas que viajan a países tropicales ha hecho que las enfermedades importadas adquieran una relevancia cada vez mayor. Las miasis (o infestaciones por larvas de moscas cutáneas se encuentran entre este tipo de enfermedades siendo especialmente frecuentes en países tropicales. A propósito de la observación de un caso de miasis cutánea masiva por Cordylobia antropophaga, que ocurrió en una mujer de 34 años de edad al volver de un viaje a Senegal, se ha efectuado una revisión de los casos de miasis cutáneas forunculoides importadas publicados en España, así como de la biología, patología, tratamiento y prevención de la miasis humana por Cordylobia anthropophaga. El caso referido, se caracterizó por la infestación con un número inusualmente elevado de larvas, no sospechándose su etiología hasta la fase final de la enfermedad. La emergencia continuada de larvas (se recogieron 91 generó en la paciente un estado de ansiedad importante. Finalmente, la eliminación de las larvas provocó una rápida mejoría de la paciente. Aunque los casos de miasis cutánea no tienen la gravedad de otras enfermedades importadas, su conocimiento es necesario desde el punto de vista preventivo, diagnóstico y terapeútico. Es importante proceder a la identificación morfológica de las larvas diferenciándolas de otro tipo de miasis con implicaciones terapéuticas diferentes.

  3. Sepsis neonatal por Estreptococos Pyogenes

    Gilberto Rodríguez-Herrera

    2009-09-01

    Full Text Available Se presenta el caso de un paciente masculino, recién nacido a término adecuado para la edad gestacional, quien nace por parto vaginal, con el antecedente de fiebre en la madre durante el periodo de postparto inmediato. Los padres consultan a los 2 días de vida pues le notan dificultad respiratoria, hipoactividad y rechazo a la leche materna. El paciente se interna y se aborda como una sepsis. Durante su estancia en el servicio de neonatología del Hospital Nacional de Niños asocia fallo respiratorio que amerita ventilación mecánica asistida por varios días en diferentes ocasiones, derrame pleural exudativo, convulsiones de origen hipóxico isquémico. Con reporte de hemocultivos positivos por Estreptococos pyogenes. El Estreptococos pyogenes o estreptococo β-hemolνtico del grupo A, fue un problema en los comienzos del siglo pasado, siendo frecuente en las infecciones puerperales y del reciιn nacido. En la actualidad es un germen sumamente raro en los procesos de sepsis neonatal.2 La gravedad de la enfermedad causada por este microorganismo en el periodo neonatal varνa desde una onfalitis crónica de bajo grado a una septicemia, una meningitis fulminante y la muerte.1 El presente artículo pretende hacer un resumen del paciente, con su evolución clínica, radiológica y además ejemplificar todas las complicaciones que tuvimos con este germen tan poco frecuente en la actualidad en sepsis neonatal.

  4. Molecular detection of Anaplasma platys, Ehrlichia canis, Hepatozoon canis and Rickettsia monacensis in dogs from Maio Island of Cape Verde archipelago.

    Lauzi, Stefania; Maia, João P; Epis, Sara; Marcos, Ricardo; Pereira, Cristina; Luzzago, Camilla; Santos, Marta; Puente-Payo, Pablo; Giordano, Alessia; Pajoro, Massimo; Sironi, Giuseppe; Faustino, Augusto

    2016-07-01

    Tick-borne diseases are emerging worldwide and have an important zoonotic relevance. Dogs play an important role in the epidemiology of several zoonotic tick-borne pathogens acting as sentinels and/or reservoirs. This study focused on the molecular identification of tick-borne pathogens in blood samples of 153 autochthonous asymptomatic dogs in Maio Island, Cape Verde archipelago. Eighty-four (54.9%) dogs were positive for one or more pathogens. Fifty-five (35.9%) dogs were infected with Hepatozoon canis, 53 (34.6%) with Anaplasma platys, five (3.3%) with Ehrlichia canis and Rickettsia monacensis, an emerging human pathogen, was also identified in a single dog (0.7%). The former three pathogens cause important canine tick-borne diseases that are transmitted or potentially transmitted by Rhipicephalus sanguineus s.l., the only hard tick identified in Cape Verde. Furthermore, Wolbachia spp. was amplified from the blood of one dog. None of the dogs were positive for Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, Midichloria mitochondrii, Bartonella spp., Babesia spp. or Theileria spp. Fifty-four (35.3%) animals showed single infections and 30 (19.6%) co-infections, with A. platys and H. canis co-infection being the most frequent (28 dogs, 18.3%). The frequency of E. canis infection was statistically different among age groups (P=0.017), being higher among dogs older than 4 years compared to younger dogs. Infection by A. platys was also statistically different among age groups (P=0.031), being higher in dogs younger than 2 years compared to older dogs. The statistical analyses showed no significant association of PCR positivity with gender or location. The frequency of tick-borne pathogens detected in dogs in Maio Island, including R. monacensis, highlights the need to improve diagnosis and control in order to prevent the risk of transmission of these pathogens among dogs and humans living in or travelling to this touristic island. PMID:27177475

  5. Alterações oftálmicas associadas à intoxicação experimental por closantel em caprinos Ophthalmic changes associated with the experimental poisoning by closantel in caprine

    R. Ecco

    2008-02-01

    Full Text Available Alterações oftálmicas foram experimentalmente induzidas em caprinos após superdosagem com o anti-helmíntico closantel. Foram usados cinco caprinos com sete a oito meses de idade, produtos do cruzamento da raça Saanen com a Pardo Alpino. Os animais mostraram sinais de intoxicação entre quatro e cinco dias após a administração do closantel. Os sinais clínicos caracterizaram-se principalmente por distúrbios neurológicos centrais e cegueira. Ao exame clínico, observaram-se midríase bilateral, perda do reflexo pupilar à luz e cegueira bilateral. À oftalmoscopia indireta, foram observadas degeneração aguda de retina e papiledema. As alterações crônicas mostravam disco óptico acinzentado, atrofia de vasos e da retina. Nos fundos tapetal e não-tapetal notavam-se áreas de despigmentação e lesões irregulares castanho-amareladas. As alterações histológicas consistiam em perda dos neurônios da camada ganglionar e das células da camada nuclear interna e externa da retina. As alterações agudas no nervo óptico e na substância branca do encéfalo foram de degeneração espongiforme. As alterações crônicas do nervo óptico caracterizavam-se por extensa necrose e infiltração de células Gitter.Ophthalmic alterations were experimentally induced after overdose with the anthelmintic closantel. Five seven to eight- months-old, Saanen x Alpine caprine were used. The animals showed clinical signs of toxicosis four to five days after the administration of closantel. Clinical signs were primarily characterized by central nervous disturbances and blindness. Clinically, bilateral mydriasis, loss of pupillary light reflex, and blindness were observed. At indirect ophthalmoscopic examination, there was acute retinal degeneration and papilledema. Chronic ocular changes consisted of paleness of the optic disc, vascular atrophy, and retinal atrophy. Areas of pigment loss and irregular yellowish-brown foci were present in the tapetal

  6. Agujeros negros vistos por fuera y por dentro

    Janssen, Bert

    2015-01-01

    La Relatividad General es la teoría moderna de la gravedad, que corrige los problemas que surgen con la gravedad descrita por Newton. Explicaremos porque la gravedad newtoniana es incompatible con la Relatividad Especial y cual es la solución que propone Einstein: la gravedad como una manifestación del espacio curvo. Hablaremos brevemente de los fenómenos que surgen de la Relatividad General, como los agujeros negros, las ondas gravitacionales y la cosmología.

  7. DNA microarray for simultaneous screening and detection of seven rickettsia%7种立克次体甄别检测基因芯片方法的建立

    李灵云; 张英杰; 王升启; 刘琪琦

    2015-01-01

    目的:建立一种能同时检测7种立克次体的化学发光基因芯片法。方法根据NCBI公开发表的7种立克次体的序列设计引物和探针,制备立克次体甄别检测基因芯片。利用多重不对称PCR法扩增立克次体靶基因片段,标记的产物与基因芯片上的探针杂交,经清洗、化学发光显色后进行结果分析。在优化的多重PCR体系、杂交反应和化学发光检测条件下,评价芯片的特异性、灵敏度、重复性。用实时荧光PCR法与芯片法分别检测莫氏立克次体梯度稀释的核酸,比较两种方法的灵敏度。制备双盲模拟样本,进一步评价芯片方法的准确性。结果该研究共筛选出1对通用引物、4对特异性引物和1条立克次体属通用探针、9条特异性检测探针。该芯片检测质粒DNA的灵敏度为1.5×102~3×103拷贝/反应,检测模拟样本的灵敏度为103~104拷贝/μl。实时荧光PCR法与芯片法检测结果一致,实时荧光PCR法比芯片法灵敏度高10倍。双盲模拟样本检测符合率为100%。结论成功建立了可同时检测7种立克次体的化学发光基因芯片检测方法,为立克次体病的临床诊断和流行病学调查提供了一种新的高通量检测手段。%Objective To develop a chemiluminescence ( CL ) imaging DNA microarray method for simultaneous detection of seven rickettsiae.Methods Primers and probes were designed based on the specific sequence of seven rickettsia genomes.The probes were immobilized on the aldehyde modified glass surface to prepare DNA microarray for rickettsiae.The nucleic acids of the selected rickettsiae were amplified and labelled by multiplex PCR method, and then hybridized with microarray that was scanned after washing and chemiluminescence coloration, before the results were analyzed.Facilitated by the optimization of the multiplex PCR system, hybridization, and chemiluminescence imagination, we evaluated the

  8. Desajuste educativo por regiones en Colombia: ¿competencia por salarios o por puestos de trabajo?

    Castillo Caicedo Maribel

    2007-08-01

    Full Text Available Este trabajo aporta una perspectiva del fenómeno de la sobreeducación,
    entendida como un desajuste por exceso, entre el nivel educativo alcanzado
    por el individuo y el exigido por el puesto de trabajo en el cual se
    desempeña; esto se debe a que existe una demanda laboral estrecha de
    puestos de trabajo para personas calificadas en Colombia. Se analizan las
    contribuciones empíricas existentes y el debate sobre las mismas; se
    examinan las teorías que permiten explicar la existencia de un desajuste
    educativo y se realiza una revisión de la literatura internacional y
    nacional sobre el tema. Adicionalmente, se plantean una serie de hipótesis
    para desarrollar un esquema que permita determinar el comportamiento
    del individuo en el fenómeno de la sobreeducación.

  9. A Vida por Outros Lados

    Maria Berenice da Costa Machado

    2003-06-01

    Full Text Available Diálogo entre a imagem e o slogan do anúncio publicitário “A vida por todos os lados”, do jornal Zero Hora (ZH, com as características da Modernidade e da Pós-modernidade. A intenção é a refletir sobre a complexidade da comunicação institucional deste diário e sua ligação com as tendências contemporâneas.

  10. Once mil metros por segundo

    2012-01-01

    Esta exposición es una ventana hacia el mundo de la Ciencia Ficción. Los sueños de escritores extraordinarios, personajes, lugares, máquinas y robots que cada día están más cerca de nuestra cotidianidad gracias a los avances de la ciencia y la tecnología hacen parte de la muestra itinerante por las sedes de la Universidad Nacional. El visitante puede recorrer los diferentes géneros que constituyen este género literario, además de conocer sus principales representantes. Así mismo se explor...

  11. Miasis ocular por Oestrus ovis

    María Beltrán F

    2006-01-01

    Full Text Available Se presentan tres casos de miasis ocular (dos adultos y un niñoprocedentes de zonas ganaderas de la provincia de Huaura,departamento de Lima,que acudieron al Hospital Regional de Huacho por presentar el ojo rojo,fotofobia, edema palpebral y sensación de cuerpo extraño;se extrajeron larvas adheridas al canto interno del ojo,las cuales se recibieron en el Instituto Nacional de Salud y fueron identificadas como Oestrus ovis .

  12. Por la puerta del fondo

    Tossi, Lucía

    2002-01-01

    Como aconteciera en el pasado, las mujeres de estos siglos participaban de diversas actividades científicas y técnicas, en las cuales la tradicional habilidad manual, destreza, sentido de la observación, inteligencia, imaginación y capacidad de trabajo, de los que siempre dieron pruebas, fueron ampliamente aprovechados. No obstante, salvo contadas excepciones, sólo pudieron entrar en la fortaleza del saber por la puerta del fondo. Algunas de esas mujeres, pertenecientes a las clases nobles y ...

  13. Sepsis neonatal por Estreptococos Pyogenes

    Gilberto Rodríguez-Herrera; Cinthya Ramírez-Navarro

    2009-01-01

    Se presenta el caso de un paciente masculino, recién nacido a término adecuado para la edad gestacional, quien nace por parto vaginal, con el antecedente de fiebre en la madre durante el periodo de postparto inmediato. Los padres consultan a los 2 días de vida pues le notan dificultad respiratoria, hipoactividad y rechazo a la leche materna. El paciente se interna y se aborda como una sepsis. Durante su estancia en el servicio de neonatología del Hospital Nacional de Niños asocia fallo respir...

  14. toxicidad neuroendocrina inducida por cadmio

    A Romero

    2008-01-01

    Full Text Available El cadmio es un agente químico tóxico importante debido a su creciente nivel en el medio ambiente como resultado de prácticas industriales y agrícolas. Como perturbador endocrino, el cadmio modifica la secreción de hormonas hipofisarias. Los efectos indirectos del cadmio provocan la generación de especies reactivas de oxígeno y reducen la actividad de las proteínas implicadas en las defensas antioxidantes. La melatonina es conocida como un potente antioxidante, scavenger de radicales libres y quelante de metales sintetizada en la glándula pineal. De esta manera, las acciones antioxidantes de esta indolamina protegen frente a la peroxidación lipídica y el daño oxidativo de los radicales y de sus productos tóxicos. Los trabajos recopilados en esta revisión ponen de manifiesto la capacidad antioxidante de la melatonina y, por lo tanto, su posible papel protector frente a la toxicidad del cadmio en lo que se refiere al estrés oxidativo y peroxidación lipídica inducidos por la exposición a este metal.

  15. Hipoglucemia inducida por carcinoma adrenal

    Jimena Soutelo

    2013-08-01

    Full Text Available El carcinoma suprarrenal es una neoplasia maligna infrecuente y de mal pronóstico. La presentación clínica más común es originada por la producción hormonal excesiva, mientras que el desarrollo de hipoglucemia sintomática es excepcional. Presentamos el caso de una mujer de 37 años que ingresó al hospital por síntomas de hipoglucemias graves, hipertensión arterial, hipopotasemia y amenorrea secundaria. En el laboratorio se halló hipoglucemia con insulina inhibida y niveles de andrógenos en rango tumoral. La tomografía computarizada (TC de abdomen y pelvis mostró voluminosa formación heterogénea de aspecto sólido sin plano de clivaje con respecto al parénquima hepático e intenso realce con contraste. Luego de la extirpación de la masa retroperitoneal, evolucionó con valores de glucemia y potasemia normales, estabilizó la presión arterial y recuperó los ciclos menstruales.

  16. Mortalidad intrahospitalaria por accidente cerebrovascular

    Federico Rodríguez Lucci

    2013-08-01

    Full Text Available La mortalidad global por accidente cerebrovascular (ACV ha disminuido en las últimas tres décadas, probablemente debido a un mejor control de los factores de riesgo vascular. La mortalidad hospitalaria por ACV ha sido tradicionalmente estimada entre 6 y 14% en la mayoría de las series comunicadas. Sin embargo, los datos de ensayos clínicos recientes sugieren que esta cifra sería sustancialmente menor. Se revisaron datos de pacientes internados con diagnóstico de ACV del Banco de Datos de Stroke de FLENI y los registros institucionales de mortalidad entre los años 2000 y 2010. Los subtipos de ACV isquémicos se clasificaron según criterios TOAST y los ACV hemorrágicos en hematomas intrapanquimatosos, hemorragias subaracnoideas aneurismáticas, malformaciones arteriovenosas y otros hematomas intraparenquimatosos. Se analizaron 1514 pacientes, 1079 (71% con ACV isquémico (grandes vasos 39%, cardioembólicos 27%, lacunares 9%, etiología indeterminada 14%, otras etiologías 11% y 435 (29% con ACV hemorrágico (intraparenquimatosos 27%, hemorragia subaracnoidea 30%, malformaciones arteriovenosas 25% y otros hematomas espontáneos 18%. Se registraron 38 muertes intrahospitalarias (17 ACV isquémicos y 21 ACV hemorrágicos, representando una mortalidad global del 2.5% (1.7% en ACV isquémicos y 4.8% en ACV hemorrágicos. No se registraron muertes asociadas al uso de fibrinolíticos endovenosos. La mortalidad intrahospitalaria en pacientes con ACV isquémico y hemorrágico en nuestro centro fue baja. El manejo en un centro dedicado a las enfermedades neurológicas y el enfoque multidisciplinario por personal médico y no médico entrenado en el cuidado de la enfermedad cerebrovascular podrían explicar, al menos en parte, estos resultados.

  17. Miotoxicidade por organofosforados Organophosphate myotoxicity

    Maria J. Cavaliere

    1996-06-01

    Full Text Available Os organofosforados são um grupo de compostos químicos amplamente utilizados em agropecuária como inseticidas, ocasionando intoxicações acidentais em animais e humanos, e mesmo sendo utilizados em tentativas de suicídio. A toxicidade desses produtos decorre sobretudo de insuficiência cárdio-respiratória por compromentimento do sistema nervoso autônomo. Sabe-se que alguns destes compostos induzem em animais de experimentação e em humanos, uma miopatia caracterizada por degeneração de células musculares, comprometendo sobretudo a musculatura respiratória. Baseado no fato de que este comprometimento contribui para a piora da função respiratória, propõe-se um protocolo de avaliação rotineira de miotoxicidade por compostos organofosforados, através de uma bateria mínima e suficiente de colorações e reações histoquímicas para quantificação da necrose muscular. Utilizaram-se como modelo experimental, grupos de ratos albinos (Wistar intoxicados com o organofosforado paraoxon, com e sem antídotos (atropina ou pralidoxima. Verificou-se nos grupos tratados com paraoxon e paraoxon mais atropina, necrose de fibras musculares no diafragma, que atingia em determinadas áreas até 15% das fibras. No grupo tratado com paraoxon mais pralidoxima, a necrose foi mínima, evidenciando o papel mioprotetor deste último antídoto.Organophosphates comprise a group of chemical compounds extensively used in farming as insecticides, which cause accidental poisoning in animals and men and are also used in suicide attempts. The toxicity of these compounds is due especially to the cardiac and respiratory impairment in consequence of autonomic nervous system disorders. However, it is known that some of these products induce a myopathy in experimental animals and humans. This myopathy is characterized by muscle cell degeneration, involving above all the respiratory muscles. Based on the fact that this involvement certainly enhances the

  18. Detecção de Ehrlichia spp./Anaplasma spp., Rickettsia spp., Mycoplasma haemofelis e Leishmania infantum em felinos errantes e sua relação com a presença de retrovírus e com a sintomatologia manifestada

    Martins, Telma Simone Oliveira

    2012-01-01

    ABSTRACT - Detection of Ehrlichia spp./Anaplasma spp., Rickettsia spp., Mycoplasma haemofelis and Leishmania infantum in stray cats, and its relation to the presence of retroviruses and the symptoms manifested - The prevalence of infectious diseases on cats is related with the density and the size of the population indwells. The objective of this work was to determinate the prevalence of the feline immunodeficiency virus (FIV), feline leukemia virus (FeLV), Ehrlichia spp./Anaplasma s...

  19. Verdad por definición

    Garrido Garrido, Julián

    1997-07-01

    Full Text Available Not available.La verdad por definición es un tipo peculiar de verdad científica, distinguible de las verdades lógicas, matemáticas y empíricas. La definición, por su parte, designa diversos procedimientos de asignación de significado, cuyas diferencias exigen una adjetivación cuidadosa: definiciones ostensivas y operacionales, definiciones de diccionario y definiciones teóricas. Pero sólo las del último tipo son verdaderas por definición. En el presente artículo se precisa el concepto formal de definición teórica, se delimita la estructura de esos enunciados, se analiza la verdad por definición, y se comparan, por último, las definiciones teóricas con los otros tipos de definición.

  20. Evolution of NADPH-cytochrome P450 oxidoreductases (POR) in Apiales - POR 1 is missing

    Andersen, Trine Bundgaard; Hansen, Niels Bjørn; Laursen, Tomas;

    2016-01-01

    The NADPH-dependent cytochrome P450 oxidoreductase (POR) is the obligate electron donor to eukaryotic microsomal cytochromes P450 enzymes. The number of PORs within plant species is limited to one to four isoforms, with the most common being two PORs per plant. These enzymes provide electrons to ...

  1. 河北省西部山区蜱传斑点热群立克次体分子流行病学研究%Molecular epidemiological study of tick-borne spotted fever group Rickettsia in western mountain area of Hebei province, China

    冯帅; 吴含; 张力文; 路朝旭; 张成龙; 李志平; 张荣贞; 周慧

    2013-01-01

    Objective To investigate the prevalence of tick-borne spotted fever group Rickettsia (SFGR) in the western mountain area of Hebei province,China and to provide a scientific basis for the prevention and control of tick-borne SFGR.Methods One set of specific primers,designed according to the outer membrane protein A (OmpA) gene sequence of SFGR,were used to amplify the OmpA gene in DNA samples extracted from Haemaphysalis longicornis collected in the western mountain area of Hebei province,and the positive samples were subjected to sequencing and sequence analysis to establish the molecular phylogenetic tree.Results Of 1227 DNA samples,91 (7.42%) were positive for SFGR.The phylogenetic analysis based on nucleotide sequence showed that all detected SFGR strains were clustered together with Candidatus Rickettsia hebeiii (accession numbers:HQ651815,HQ651817,HQ651818,HQ651819,HQ651823,and HQ651824) and Rickettsia sp.Fujian strain FUJ (accession number:AF169629); these strains had the highest homology with Candidatus R.hebeiii (99.02%),followed by Rickettsia sp.Fujian strain FUJ (98.50%),Rickettsia sp.Suifen strain HLJ-054 (accession number:AF179362) and Rickettsia sp.Hulin strain HL-93 (accession number:AF179364) (98.13%),and Rickettsia sp.Japanese strain YM (accession number:U43795) (97.92%).Conclusion Tick-borne SFGR is prevalent in the western mountain area of Hebei province.Preventive measures should be taken in time to protect humans and animals from this disease.%目的 调查河北省西部山区蜱类斑点热群立克次体带菌情况,为蜱传斑点热群防控提供科学依据.方法 根据已发表斑点热群立克次体OmpA外膜蛋白基因序列设计特异性引物,对河北省西部山区采集的长角血蜱进行PCR检测,并对阳性样本进行测序和序列分析,建立分子系统进化树.结果 在1227份蜱DNA样本中检测出91份阳性,阳性率为7.42%;序列分析结果显示河北省西部山区长角血蜱携带立克

  2. Verdad por definición

    Garrido Garrido, Julián

    1997-01-01

    Not available.La verdad por definición es un tipo peculiar de verdad científica, distinguible de las verdades lógicas, matemáticas y empíricas. La definición, por su parte, designa diversos procedimientos de asignación de significado, cuyas diferencias exigen una adjetivación cuidadosa: definiciones ostensivas y operacionales, definiciones de diccionario y definiciones teóricas. Pero sólo las del último tipo son verdaderas por definición. En el presente artículo se precisa el concepto formal ...

  3. La responsabilidad civil medioambiental por productos defectuosos

    Siaka, Danny Clovis

    2014-01-01

    La tesis cuestiona por una parte la exhaustividad del marco regulador de la responsabilidad Civil por productos defectuosos y, por la otra, la singularidad de los daños medioambientales. Así, pretende, entre otros objetivos, contribuir en la construcción del Derecho Civil medioambiental, buscando, dentro del ámbito de protección de la legislación sobre productos defectuosos, el posible anclaje de los daños medioambientales. Gira en torno a la cuestión del régimen aplicable a supuesto...

  4. 14 Nobel, preocupados por el CERN

    Rivera, A

    2003-01-01

    "E l presidente del Consejo del CERN (Laboratorio Europeo de Fisica de Particulas, junto a Ginebra), Maurice Bourquin, ha recibido una carta firmada por un grupo de cientificos muy especiales: 14 premios Nobel de Fisica" (1 page).

  5. Intoxicación por Paraquat

    Glenda Viales López

    2014-01-01

    El paraquat es un herbicida bipiridílico que actúa por contacto, se presenta en forma líquida en concentraciones del 20% para uso agrícola. Su nombre químico es eI 1-1´-dimetil-4-4- bipiridilo, con el nombre comercial de Gramoxone. La intoxicación por paraquat tiene una tasa de mortalidad elevada. La intoxicación grave se caracteriza por la afectación de múltiples órganos, principalmente los pulmones, los riñones y el hígado. El pulmón es el órgano diana en la intoxicación por paraquat y la i...

  6. Intoxicación por Paraquat

    Glenda Viales López

    2014-12-01

    Full Text Available El paraquat es un herbicida bipiridílico que actúa por contacto, se presenta en forma líquida en concentraciones del 20% para uso agrícola. Su nombre químico es eI 1-1´-dimetil-4-4- bipiridilo, con el nombre comercial de Gramoxone. La intoxicación por paraquat tiene una tasa de mortalidad elevada. La intoxicación grave se caracteriza por la afectación de múltiples órganos, principalmente los pulmones, los riñones y el hígado. El pulmón es el órgano diana en la intoxicación por paraquat y la insuficiencia respiratoria con fibrosis pulmonar aguda es la causa más común de muerte.

  7. La pintura vista por un pintor joven

    Fuentes Pozo, Pedro

    2000-01-01

    Full Text Available Not available

    El pintor se define a lo largo del tiempo como un artista en mutación influenciado por la sociedad de su momento y por su propio mundo interior Esto ha contribuido a la creación de distintos estilos pictóricos y a una evolución que conlleva la despreocupación por el aspecto formal en aras de una introspección al mundo interior En el cambio constante se refleja la búsqueda del artista que valida la intemporalidad del arte. Así, el verdadero artista sobrevive al aplauso o rechazo de la crítica, convirtiéndose en un verdadero hombre renancentista preocupado por el hallazgo del conocimiento universal.

  8. Manejo conservador de una fistula de quilo por diseción radical de cuello: reporte de un caso y revisión de la literatura

    E Brenes Leñero

    2015-12-01

    Full Text Available Se expone el caso de un paciente masculino de 59 años con diagnóstico de carcinoma medular de tiroides con metástasis ganglionares, al cual se le realiza una tiroidectomía total bilateral con disección radical de cuello modificada tipo III. En el postoperatorio se documenta fístula del conducto torácico. Se dio un manejo conservador con dieta hiperprotéica sin carbohidratos y rica en triglicéridos de cadena media el cual fue satisfactorio.

  9. Manejo conservador de una fistula de quilo por diseción radical de cuello: reporte de un caso y revisión de la literatura

    E Brenes Leñero; M Murillo Ceciliano; E Mora Segura

    2015-01-01

    Se expone el caso de un paciente masculino de 59 años con diagnóstico de carcinoma medular de tiroides con metástasis ganglionares, al cual se le realiza una tiroidectomía total bilateral con disección radical de cuello modificada tipo III. En el postoperatorio se documenta fístula del conducto torácico. Se dio un manejo conservador con dieta hiperprotéica sin carbohidratos y rica en triglicéridos de cadena media el cual fue satisfactorio.

  10. Intoxicación por paraquat

    Norma A. Hernández Hernández; Martínez, Miguel A.

    2000-01-01

    En el periodo comprendido de 1996 a 1999, se revisaron los expedientes clínicos de enfermos intoxicados por biperidilos (Paraquat), para determinar las principales manifestaciones, complicaciones, tratamiento y pronóstico del tóxico. Se realizó un estudio retrospectivo, transversal, descriptivo y observacional, en el área de Medicina Interna del Hospital General Dr. Gustavo A. Rovirosa Pérez. Se estudiaron 18 pacientes con intoxicación por paraquat, dos se excluyeron p...