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

Czech Academy of Sciences Publication Activity Database

Hajdušková, Eva; Literák, I.; Papoušek, I.; Costa, F.B.; Nováková, M.; Labruna, M. B.; Zdražilová-Dubská, L.

2016-01-01

Roč. 7, č. 3 (2016), s. 482-486 ISSN 1877-959X Institutional support: RVO:60077344 Keywords : Rickettsiae * Candidatus Rickettsia mendelii * Ixodes ricinus * basal group rickettsiae * ticks * Czech Republic Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.230, year: 2016

Phylogenetic Variants of Rickettsia africae, and Incidental Identification of "Candidatus Rickettsia Moyalensis" in Kenya.

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Kimita, Gathii; Mutai, Beth; Nyanjom, Steven Ger; Wamunyokoli, Fred; Waitumbi, John

2016-07-01

Rickettsia africae, the etiological agent of African tick bite fever, is widely distributed in sub-Saharan Africa. Contrary to reports of its homogeneity, a localized study in Asembo, Kenya recently reported high genetic diversity. The present study aims to elucidate the extent of this heterogeneity by examining archived Rickettsia africae DNA samples collected from different eco-regions of Kenya. To evaluate their phylogenetic relationships, archived genomic DNA obtained from 57 ticks a priori identified to contain R. africae by comparison to ompA, ompB and gltA genes was used to amplify five rickettsial genes i.e. gltA, ompA, ompB, 17kDa and sca4. The resulting amplicons were sequenced. Translated amino acid alignments were used to guide the nucleotide alignments. Single gene and concatenated alignments were used to infer phylogenetic relationships. Out of the 57 DNA samples, three were determined to be R. aeschlimanii and not R. africae. One sample turned out to be a novel rickettsiae and an interim name of "Candidatus Rickettsia moyalensis" is proposed. The bonafide R. africae formed two distinct clades. Clade I contained 9% of the samples and branched with the validated R. africae str ESF-5, while clade II (two samples) formed a distinct sub-lineage. This data supports the use of multiple genes for phylogenetic inferences. It is determined that, despite its recent emergence, the R. africae lineage is diverse. This data also provides evidence of a novel Rickettsia species, Candidatus Rickettsia moyalensis.

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

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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.

21 CFR 866.3500 - Rickettsia serological reagents.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rickettsia serological reagents. 866.3500 Section... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3500 Rickettsia serological reagents. (a) Identification. Rickettsia serological reagents are devices that consist of antigens...

Human Infection with Rickettsia felis, Kenya

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2010-07-01

Human Infection with Rickettsia felis, Kenya Allen L. Richards, Ju Jiang, Sylvia Omulo, Ryan Dare, Khalif Abdirah~a~, P:bdile Ali, Shanaaz K...infection with obligate intracellular rickettsiae , which are transmitted to humans by arthropod vectors (e.g., lice, fleas, ticks, and mites... Rickettsiae are associated with arthropods for a least a part of their life cycle and are passed to other arthropods by transovarial transmission or

Rickettsia parkeri and "Candidatus Rickettsia andeanae" in Questing Amblyomma maculatum (Acari: Ixodidae) From Mississippi.

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Lee, J K; Moraru, G M; Stokes, J V; Wills, R W; Mitchell, E; Unz, E; Moore-Henderson, B; Harper, A B; Varela-Stokes, A S

2017-03-01

Amblyomma maculatum Koch (Acari: Ixodidae), the primary vector for Rickettsia parkeri, may also be infected with a rickettsia of unknown pathogenicity, "Candidatus Rickettsia andeanae." Infection rates with these rickettsiae vary geographically, and coinfected ticks have been reported. In this study, infection rates of R. parkeri and "Ca. R. andeanae" were evaluated, and rickettsial DNA levels quantified, in 335 questing adult A. maculatum collected in 2013 (n = 95), 2014 (n = 139), and 2015 (n = 101) from Oktibbeha County, MS. Overall infection rates of R. parkeri and "Ca. R. andeanae" were 28.7% and 9.3%, respectively, with three additional A. maculatum (0.9%) coinfected. While R. parkeri-infected ticks were detected all three years (34.7% in 2013; 13.7% in 2014; 43.6% in 2015), "Ca. R. andeanae" was not detected in 2013, and was detected at rates of 10.8% in 2014, and 15.8% in 2015. Interestingly, rickettsial DNA levels in singly-infected ticks were significantly lower in "Ca. R. andeanae"-infected ticks compared to R. parkeri-infected ticks (P Rickettsia species in A. maculatum at the population level. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Genetic variability of Rickettsia spp. in Ixodes persulcatus/Ixodes trianguliceps sympatric areas from Western Siberia, Russia: Identification of a new Candidatus Rickettsia species.

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Igolkina, Yana P; Rar, Vera A; Yakimenko, Valeriy V; Malkova, Marina G; Tancev, Aleksey K; Tikunov, Artem Yu; Epikhina, Tamara I; Tikunova, Nina V

2015-08-01

Rickettsia spp. are the causative agents of a number of diseases in humans. These bacteria are transmitted by arthropods, including ixodid ticks. DNA of several Rickettsia spp. was identified in Ixodes persulcatus ticks, however, the association of Ixodes trianguliceps ticks with Rickettsia spp. is unknown. In our study, blood samples of small mammals (n=108), unfed adult I. persulcatus ticks (n=136), and I. persulcatus (n=12) and I. trianguliceps (n=34) ticks feeding on voles were collected in two I. persulcatus/I. trianguliceps sympatric areas in Western Siberia. Using nested PCR, ticks and blood samples were studied for the presence of Rickettsia spp. Three distinct Rickettsia species were found in ticks, but no Rickettsia species were found in the blood of examined voles. Candidatus Rickettsia tarasevichiae DNA was detected in 89.7% of unfed I. persulcatus, 91.7% of engorged I. persulcatus and 14.7% of I. trianguliceps ticks. Rickettsia helvetica DNA was detected in 5.9% of I. trianguliceps ticks. In addition, a new Rickettsia genetic variant was found in 32.4% of I. trianguliceps ticks. Sequence analysis of the 16S rRNA, gltA, ompA, оmpB and sca4 genes was performed and, in accordance with genetic criteria, a new Rickettsia genetic variant was classified as a new Candidatus Rickettsia species. We propose to name this species Candidatus Rickettsia uralica, according to the territory where this species was initially identified. Candidatus Rickettsia uralica was found to belong to the spotted fever group. The data obtained in this study leads us to propose that Candidatus Rickettsia uralica is associated with I. trianguliceps ticks. Copyright © 2015 Elsevier B.V. All rights reserved.

Prevalence data of Rickettsia slovaca and other SFG Rickettsiae species in Dermacentor marginatus in the southeastern Iberian peninsula.

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Márquez, F J; Rojas, A; Ibarra, V; Cantero, A; Rojas, J; Oteo, J A; Muniain, M A

2006-10-01

In southern Spain, Dermacentor marginatus ticks can be infected with several genospecies of spotted fever Group (SFG) Rickettsia. We developed a nested polymerase chain reaction assay by using a species-specific probe targeting the ompA gene to detect and differentiate between the two groups of rickettsiae previously described in D. marginatus. SFG rickettsia has been detected in 85.15% of ticks studied (26.7% of positives have been to R. slovaca, the causative agent of TIBOLA-DEBONEL, and 73.3% to SFG rickettsia closely related to strains RpA4-JL-02-DnS14-DnS28).

“Candidatus Rickettsia andeanae” en Amblyomma tigrinum, San Luis, Argentina

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Gabriel CICUTTIN

2016-11-01

Full Text Available El objetivo del estudio fue detectar especies del género Rickettsia en garrapatas de la especie Amblyomma tigrinum colectadas sobre carnívoros domésticos y en sangre de caninos domésticos de la provincia de San Luis (Argentina. Entre 2013 y 2015 se colectaron 56 garrapatas adultas de la especie A. tigrinum sobre caninos y felinos domésticos, y se obtuvieron 65 muestras sanguíneas de caninos. Tres garrapatas resultaron positivas mediante la amplificación de un fragmento del espacio intergénico 23S-5S ARNr del género Rickettsia, lográndose secuenciar uno de los productos positivos. La muestra positiva secuenciada también resultó positiva por PCRs de los fragmentos de los genes gltA y ompA. Las secuencias obtenidas resultaron tener una identidad del 100 % de identidad con “Candidatus Rickettsia andeanae”. Todas las muestras sanguíneas resultaron negativas. “Ca. R. andeanae” no ha sido asociada con enfermedad en humanos o animales, sin embargo, es necesario realizar nuevas investigaciones para lograr un mayor conocimiento del riesgo potencial de transmisión de rickettsiosis en la región. SUMMARY. “Candidatus Rickettsia andeanae” in Amblyomma tigrinum ticks from San Luis (Argentina. The aim of this study was to detect species of Rickettsia in Amblyomma tigrinum ticks collected from domestic carnivores and blood of domestic dogs of San Luis (Argentina. Between 2013 and 2015, 56 adults of A. tigrinum from dogs and cats and 65 blood from dogs were collected. Three ticks were positive by amplification of a 23S-5S rRNA fragment, and the sequence of one of the positive products was obtained. The positive sample sequenced was positive by PCRs of fragments of genes gltA and ompA. The sequences obtained were 100% identical with "Candidatus Rickettsia andeanae". All blood samples were negative. “Ca. R. andeanae” has not been associated with disease in humans or animals; however, further research is necessary to achieve greater

Serologic evidence of the exposure of small mammals to spotted-fever Rickettsia and Rickettsia bellii in Minas Gerais, Brazil.

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Coelho, Marcella Gonçalves; Ramos, Vanessa do Nascimento; Limongi, Jean Ezequiel; de Lemos, Elba Regina Sampaio; Guterres, Alexandro; da Costa Neto, Sócrates Fraga; Rozental, Tatiana; Bonvicino, Cibele Rodrigues; D'Andrea, Paulo Sérgio; Moraes-Filho, Jonas; Labruna, Marcelo Bahia; Szabó, Matias Pablo Juan

2016-03-31

Sources of pathogenic Rickettsia in wildlife are largely unknown in Brazil. In this work, potential tick vectors and seroreactivity of small mammals against four spotted-fever group Rickettsia (R. rickettsii, R. parkeri, R. amblyommii and R. rhipicephali) and Rickettsia bellii from peri-urban areas of Uberlândia, a major town in Brazil, are described for the first time. Small mammals were captured and blood samples collected. Ticks were collected from the surface of the host and the environment and posteriorly identified. Reactivity of small mammal sera to Rickettsia was tested by indirect immunofluorescence assay (IFA) using crude antigens from five Brazilian Rickettsia isolates. Information was obtained from 416 small mammals (48 Marsupialia and 368 Rodentia). Forty-eight animals were parasitized and two tick species, Ixodes loricatus and Amblyomma dubitatum, were found on several host species, with a few tick-host relationships described for the first time. From the 416 tested sera, 70 reacted to at least one Rickettsia antigen (prevalence of 16.8%) and from these, 19 (27.1%) reacted to two or more antigens. Seroprevalence was higher for marsupials (39.6%) than for rodents (13.8%). Marsupial and Rhipidomys spp. sera reacted mainly (highest seroprevalence and titers) to R. bellii, and that of Necromys lasiurus mainly to R. rickettsii. Although the serologic assays poorly discriminate between closely related spotted-fever group Rickettsia, the observed small mammal seroreactivity suggests the circulation of Rickettsia in the peri-urban area of Uberlândia, albeit at low levels.

Isolation and characterization of a novel Rickettsia species (Rickettsia asembonensis sp. nov.) obtained from cat fleas (Ctenocephalides felis).

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Maina, Alice N; Luce-Fedrow, Alison; Omulo, Sylvia; Hang, Jun; Chan, Teik-Chye; Ade, Fredrick; Jima, Dereje D; Ogola, Eric; Ge, Hong; Breiman, Robert F; Njenga, Moses K; Richards, Allen L

2016-11-01

A novel rickettsial agent, 'Candidatus Rickettsia asembonensis' strain NMRCiiT, was isolated from cat fleas, Ctenocephalides felis, from Kenya. Genotypic characterization of the new isolate based on sequence analysis of five rickettsial genes, rrs, gltA, ompA, ompB and sca4, indicated that this isolate clustered with Rickettsia felis URRWXCal2. The degree of nucleotide similarity demonstrated that isolate NMRCiiT belongs within the genus Rickettsia and fulfils the criteria for classification as a representative of a novel species. The name Rickettsia asembonensis sp. nov. is proposed, with NMRCiiT (=DSM 100172T=CDC CRIRC RAS001T=ATCC VR-1827T) as the type strain.

Rickettsia gravesii sp. nov.: a novel spotted fever group rickettsia in Western Australian Amblyomma triguttatum triguttatum ticks.

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Abdad, Mohammad Y; Abdallah, Rita Abou; Karkouri, Khalid El; Beye, Mamadou; Stenos, John; Owen, Helen; Unsworth, Nathan; Robertson, Ian; Blacksell, Stuart D; Nguyen, Thi-Tien; Nappez, Claude; Raoult, Didier; Fenwick, Stan; Fournier, Pierre-Edouard

2017-09-01

A rickettsial organism harboured by Amblyomma triguttatum ticks on Barrow Island, Western Australia, was discovered after reports of possible rickettsiosis among local workers. Subsequent isolation of this rickettsia (strain BWI-1) in cell culture and analysis of its phylogenetic, genotypic and phenotypic relationships with type strains of Rickettsia species with standing in nomenclature suggested that it was sufficiently divergent to warrant its classification as a new species. Multiple gene comparison of strain BWI-1 revealed degrees of sequence similarity with Rickettsia raoultii, its closest relative, of 99.58, 98.89, 97.03, 96.93 and 95.73 % for the 16S rRNA, citrate synthase, ompA, ompB and sca4 genes, respectively. Serotyping in mice also demonstrated that strain BWI-1T was distinct from Rickettsia raoultii. Thus, we propose the naming of a new species, Rickettsia gravesii sp. nov., based on its novel genotypic and phenotypic characteristics. Strain BWI-1T was deposited in the ATCC, CSUR and ARRL collections under reference numbers VR-1664, CSUR R172 and RGBWI-1, respectively.

Plasmids and rickettsial evolution: insight from Rickettsia felis.

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Joseph J Gillespie

2007-03-01

Full Text Available 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.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.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 the acquirement of virulence traits in pathogenic strains, and the

Primeiro caso de febre maculosa brasileira branda associada à artrite

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Virgínia Lucia Nazario Bonoldi

2014-06-01

Full Text Available Descrevemos o primeiro caso brasileiro de Riquetsiose branda, agravada por monoartrite em joelho, em adulto jovem picado por carrapato na perna esquerda na região de Camburi, localizada no município de São Sebastião, sul da região costeira do estado de São Paulo, Mata Atlântica, Brasil. O paciente apresentou uma escara de inoculação no local da picada do carrapato, associada ao aumento ganglionar em virilha esquerda, febre, poliartralgia, cefaleia e erupção macular. Vinte dias após o episódio da picada de carrapato, o paciente apresentou monoartrite em joelho direito. O diagnóstico de Riquetsiose branda foi estabelecido pela análise imunológica sequencial em amostras de soro e líquido sinovial, tendo sido empregada a técnica de imunofluorescência (IF indireta para anticorpos reativos contra Rickettsia parkeri e Rickettsia rickettsii. A Riquetsiose branda é uma zoonose emergente, que deve ser investigada pelos médicos, incluindo reumatologistas, em pacientes que apresentem erupção macular, febre e, eventualmente, artrite, após visita ao sul da região costeira da Mata Atlântica no Brasil.

Electrotransformation and clonal isolation of Rickettsia species

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Riley, Sean P; Macaluso, Kevin R; Martinez, Juan J

2015-01-01

Genetic manipulation of obligate intracellular bacteria of the genus Rickettsia is currently undergoing a rapid period of change. The development of viable genetic tools, including replicative plasmids, transposons, homologous recombination, fluorescent protein-encoding genes, and antibiotic selectable markers has provided the impetus for future research development. This unit is designed to coalesce the basic methods pertaining to creation of genetically modified Rickettsia. The unit describes a series of methods, from inserting exogenous DNA into Rickettsia to the final isolation of genetically modified bacterial clones. Researchers working towards genetic manipulation of Rickettsia or similar obligate intracellular bacteria will find these protocols to be a valuable reference. PMID:26528784

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

NARCIS (Netherlands)

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

2009-01-01

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.

Exotic Rickettsiae in Ixodes ricinus: fact or artifact?

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Tijsse-Klasen, E.; Fonville, M.; Overbeek, van L.S.; Reimerink, J.H.J.; Sprong, H.

2010-01-01

Several pathogenic Rickettsia species can be transmitted via Ixodes ricinus ticks to humans and animals. Surveys of I. ricinus for the presence of Rickettsiae using part of its 16S rRNA gene yield a plethora of new and different Rickettsia sequences. Interpreting these data is sometimes difficult

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

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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

Detection of Borrelia lusitaniae, Rickettsia sp. IRS3, Rickettsia monacensis, and Anaplasma phagocytophilum in Ixodes ricinus collected in Madeira Island, Portugal.

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de Carvalho, Isabel Lopes; Milhano, Natacha; Santos, Ana Sofia; Almeida, Victor; Barros, Silvia C; De Sousa, Rita; Núncio, Maria Sofia

2008-08-01

A total of 300 Ixodes ricinus ticks were tested by polymerase chain reaction (PCR) for the presence of Borrelia spp., Rickettsia spp., and Anaplasma phagocytophilum. Sequence analysis demonstrated 8 (2.7%) ticks infected with B. lusitaniae, 60 (20%) with Rickettsia spp., and 1 (0.3%) with A. phagocytophilum. Seven (2.3%) ticks were coinfected with B. lusitaniae and Rickettsia spp., 2 (0.6%) with R. monacensis, and 5 (1.7%) with Rickettsia sp. IRS3. The results of this study suggest simultaneous transmission of multiple tick-borne agents on Madeira Island, Portugal.

Rickettsiae and rickettsial diseases in Croatia: Implications for travel medicine.

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Dzelalija, Boris; Punda-Polic, Volga; Medic, Alan; Dobec, Marinko

To review the current state of knowledge concerning rickettsiae and rickettsioses in Croatia and to discuss their implications for travellers. The PubMed database was searched from 1991 to 2015 by combining the words "rickettsia," "rickettsiosis", "travellers" and "Croatia". Since 1969, Croatia appears to be free of epidemic typhus (ET) caused by Rickettsia prowazekii and the last case of Brill-Zinsser disease was recorded in 2008. Mediterranean spotted fever (MSF) caused by Rickettsia conorii is the most frequent human rickettsial infection in Croatia, followed by murine typhus caused by Rickettsia typhi. Human cases of MSF and murine typhus have been predominantly observed along the eastern Adriatic coast from Zadar to Dubrovnik and between Zadar and Split, respectively. Rickettsia akari, etiologic agent of rickettsialpox, was isolated from blood of a patient diagnosed with MSF in Zadar, but no cases of rickettsialpox were reported. Several species of pathogenic (Rickettsia slovaca, Rickettsia aeschlimannii, Ricketsia helvetica, and Ricketsia raoultii) and species of undetermined pathogenicity (Ricketsia hoogstraalii sp. nov.) rickettsiae were identified in ticks collected in different ecological regions of Croatia. A search of the literature revealed no evidence of rickettsial infection in travellers visiting Croatia. Three imported cases of Rickettsia africae were observed in travellers returning from South Africa. Rickettsiae and rickettsial diseases continue to be present in Croatia. As they can be acquired while travelling, physicians should consider rickettsial infection in the differential diagnosis of patients returning from Croatia and presenting with febrile illness. Copyright © 2016 Elsevier Ltd. All rights reserved.

Seroprevalencia de Hantavirus, Rickettsia y Chikungunya en población indígena del municipio de Tuchín, Córdoba

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Samia Barrera

Full Text Available Introducción: La vigilancia de las enfermedades transmitidas por vectores es importante para establecer medidas de control en salud pública. Las poblaciones indígenas de Córdoba viven en condiciones geoclimáticas que favorecen la presencia de vectores que podrían permitir la diseminación y aparición de hantavirosis, rickettsiosis y fiebre por el virus Chikungunya. Objetivo: Establecer la seroprevalencia de Hantavirus, Rickettsia sp. y Chikungunya en la población indígena de Tuchín, Córdoba. Materiales y métodos: Se realizó un estudio descriptivo de corte transversal en 190 individuos del resguardo indígena del municipio de Tuchín; el muestreo fue realizado entre agosto y diciembre del 2012. La detección de anticuerpos IgG contra Hantavirus se llevó a cabo con la prueba IgG DxSelectTM (Focus Technologies, EL1600G, California, EE. UU., anticuerpos IgG contra Rickettsia sp. se determinaron por inmunofluorescencia indirecta y se realizó detección de anticuerpos IgG contra el virus Chikungunya mediante ELISA de captura (Nova-Tec, inmunodiagnostica GmbH, CHIG0590, Alemania. Resultados: De 190 sueros analizados, el 5,2% (10/190 fueron positivos para Rickettsia sp. del grupo de la fiebre manchada, para Hantavirus 7 de 87 (8% fueron positivos y no se encontraron positivos para Chikungunya. No se encontraron diferencias significativas (p = 0,05 entre los seropositivos de Hantavirus y Rickettsia sp. para las variables género, edad y ocupación. Conclusiones: Los hallazgos demuestran exposición previa a Rickettsia sp. y a Hantavirus en la población indígena de Tuchín. Los resultados pueden ser útiles para establecer una alerta sobre estas fiebres hemorrágicas. Aunque no se hallaron seropositivos para Chikungunya, este fue el primer trabajo de vigilancia epidemiológica realizado en Colombia sobre este virus.

Detecting Rickettsia parkeri Infection from Eschar Swab Specimens

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2013-05-01

Detecting Rickettsia parkeri Infection from Eschar Swab Specimens Todd Myers, Tahaniyat Lalani, Mike Dent, Ju Jiang, Patrick L. Daly, Jason D...Maguire, and Allen L. Richards The typical clinical presentation of several spotted fever group Rickettsia infections includes eschars. Clinical...diagnosis by using an eschar swab specimen from patients infected with Rickettsia parkeri. Until 2004, all confirmed cases of tick-borne spotted

Rickettsia bellii, Rickettsia amblyommii, and Laguna Negra hantavirus in an Indian reserve in the Brazilian Amazon.

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de Barros Lopes, Lívia; Guterres, Alexandro; Rozental, Tatiana; Carvalho de Oliveira, Renata; Mares-Guia, Maria Angélica; Fernandes, Jorlan; Figueredo, José Ferreira; Anschau, Inês; de Jesus, Sebastião; V Almeida, Ana Beatriz M; Cristina da Silva, Valéria; Gomes de Melo Via, Alba Valéria; Bonvicino, Cibele Rodrigues; D'Andrea, Paulo Sérgio; Barreira, Jairo Dias; Sampaio de Lemos, Elba Regina

2014-04-17

The purpose of this study was to identify the presence of rickettsia and hantavirus in wild rodents and arthropods in response to an outbreak of acute unidentified febrile illness among Indians in the Halataikwa Indian Reserve, northwest of the Mato Grosso state, in the Brazilian Amazon. Where previously surveillance data showed serologic evidence of rickettsia and hantavirus human infection. The arthropods were collected from the healthy Indian population and by flagging vegetation in grassland or woodland along the peridomestic environment of the Indian reserve. Wild rodents were live-trapped in an area bordering the reserve limits, due the impossibility of capturing wild animals in the Indian reserve. The wild rodents were identified based on external and cranial morphology and karyotype. DNA was extracted from spleen or liver samples of rodents and from invertebrate (tick and louse) pools, and the molecular characterization of the rickettsia was through PCR and DNA sequencing of fragments of two rickettsial genes (gltA and ompA). In relation to hantavirus, rodent serum samples were serologically screened by IgG ELISA using the Araraquara-N antigen and total RNA was extracted from lung samples of IgG-positive rodents. The amplification of the complete S segment was performed. A total of 153 wild rodents, 121 louse, and 36 tick specimens were collected in 2010. Laguna Negra hantavirus was identified in Calomys callidus rodents and Rickettsia bellii, Rickettsia amblyommii were identified in Amblyomma cajennense ticks. Zoonotic diseases such as HCPS and spotted fever rickettsiosis are a public health threat and should be considered in outbreaks and acute febrile illnesses among Indian populations. The presence of the genome of rickettsias and hantavirus in animals in this Indian reserve reinforces the need to include these infectious agents in outbreak investigations of febrile cases in Indian populations.

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

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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.

Rickettsia massiliae infection and SENLAT syndrome in Romania.

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Zaharia, Mihaela; Popescu, Corneliu Petru; Florescu, Simin Aysel; Ceausu, Emanoil; Raoult, Didier; Parola, Philippe; Socolovschi, Cristina

2016-07-01

The purpose of this prospective study is to describe the clinical and epidemiological characteristics of rickettsioses in Romania, where only Rickettsia conorii is known by clinicians but new Rickettsia species have been identified recently in ticks. A total of eight patients, including a nine-year-old child, were included between June 2011 and June 2012, in the Hospital for Infectious and Tropical Diseases, Bucharest, Romania. Seven cases presented during summer months and one in spring. Six patients presented a generalized rash with fever, myalgia and skin eschar. The last two patients presented a typical SENLAT syndrome, characterized by scalp eschar and neck lymphadenopathy. Using serological tools, we confirmed for the first time two cases of Rickettsia massiliae, the agent of spotted fever disease, and one case of Rickettsia slovaca, and one case of R. slovacaRickettsia raoultii the agents of SENLAT syndrome. Copyright © 2016 Elsevier GmbH. All rights reserved.

Rickettsia vini n. sp. (Rickettsiaceae) infecting the tick Ixodes arboricola (Acari: Ixodidae).

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Novakova, Marketa; Costa, Francisco B; Krause, Frantisek; Literak, Ivan; Labruna, Marcelo B

2016-08-26

Recently, a new rickettsia named 'Candidatus Rickettsia vini' belonging to the spotted fever group has been molecularly detected in Ixodes arboricola ticks in Spain, the Czech Republic, Slovakia and Turkey, with prevalence reaching up to 100 %. The aim of this study was to isolate this rickettsia in pure culture, and to describe it as a new Rickettsia species. A total of 148 ornitophilic nidicolous ticks Ixodes arboricola were collected in a forest near Breclav (Czech Republic) and examined for rickettsiae. Shell vial technique was applied to isolate rickettsiae in Vero cells. Rickettsial isolation was confirmed by optical microscopy and sequencing of partial sequences of the rickettsial genes gltA, ompA, ompB, and htrA. Laboratory guinea pigs and chickens were used for experimental infestations and infections. Animal blood sera were tested by immunofluorescence assay employing crude antigens of various rickettsiae. Rickettsia vini n. sp. was successfully isolated from three males of I. arboricola. Phylogenetic analysis of fragments of 1092, 590, 800, and 497 nucleotides of the gltA, ompA, ompB, and htrA genes, respectively, showed closest proximity of R. vini n. sp. to Rickettsia japonica and Rickettsia heilongjiangensis belonging to the spotted fever group. Experimental infection of guinea pigs and chickens with R. vini led to various levels of cross-reactions of R. vini-homologous antibodies with Rickettsia rickettsii, Rickettsia parkeri, 'Candidatus Rickettsia amblyommii', Rickettsia rhipicephali, Rickettsia bellii, and Rickettsia felis. Laboratory infestations by R. vini-infected I. arboricola larvae on chickens led to no seroconversion to R. vini n. sp., nor cross-reactions with R. rickettsii, R. parkeri, 'Ca. R. amblyommii', R. rhipicephali, R. bellii or R. felis. Our results suggest that R. vini n. sp. is possibly a tick endosymbiont, not pathogenic for guinea pigs and chickens. Regarding specific phenotypic characters and significant differences of DNA

A Novel Rickettsia Species Detected in Vole Ticks (Ixodes angustus) from Western Canada

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Anstead, Clare A.

2013-01-01

The genomic DNA of ixodid ticks from western Canada was tested by PCR for the presence of Rickettsia. No rickettsiae were detected in Ixodes sculptus, whereas 18% of the I. angustus and 42% of the Dermacentor andersoni organisms examined were PCR positive for Rickettsia. The rickettsiae from each tick species were characterized genetically using multiple genes. Rickettsiae within the D. andersoni organisms had sequences at four genes that matched those of R. peacockii. In contrast, the Rickettsia present within the larvae, nymphs, and adults of I. angustus had novel DNA sequences at four of the genes characterized compared to the sequences available from GenBank for all recognized species of Rickettsia and all other putative species within the genus. Phylogenetic analyses of the sequence data revealed that the rickettsiae in I. angustus do not belong to the spotted fever, transitional, or typhus groups of rickettsiae but are most closely related to “Candidatus Rickettsia kingi” and belong to a clade that also includes R. canadensis, “Candidatus Rickettsia tarasevichiae,” and “Candidatus Rickettsia monteiroi.” PMID:24077705

Plant-mediated horizontal transmission of Rickettsia endosymbiont between different whitefly species.

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Li, Yi-Han; Ahmed, Muhammad Z; Li, Shao-Jian; Lv, Ning; Shi, Pei-Qiong; Chen, Xiao-Sheng; Qiu, Bao-Li

2017-12-01

A growing number of studies have revealed the presence of closely related endosymbionts in phylogenetically distant arthropods, indicating horizontal transmission of these bacteria. Here we investigated the interspecific horizontal transmission of Rickettsia between two globally invasive whitefly species, Bemisia tabaci MEAM1 and B. tabaci MED, via cotton plants. We found both scattered and confined distribution patterns of Rickettsia in these whiteflies. After entering cotton leaves, Rickettsia was restricted to the leaf phloem vessels and could be taken up by both species of the Rickettsia-free whitefly adults, but only the scattered pattern was observed in the recipient whiteflies. Both the relative quantity of Rickettsia and the efficiency of transmitting Rickettsia into cotton leaves were significantly higher in MEAM1 females than in MED females. The retention time of Rickettsia transmitted from MEAM1 into cotton leaves was at least 5 days longer than that of MED. Phylogenetic analysis based on 16S rRNA and gltA genes confirmed that the Rickettsia extracted from the donor MEAM1, the cotton leaves, the recipient MEAM1 and the recipient MED were all identical. We conclude that cotton plants can mediate horizontal transmission of Rickettsia between different insect species, and that the transmission dynamics of Rickettsia vary with different host whitefly species. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

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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. Copyright © 2016 Elsevier GmbH. All rights reserved.

Rickettsiae in questing Ixodes ricinus ticks in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Venclíková, Kristýna; Rudolf, Ivo; Mendel, Jan; Betášová, Lenka; Hubálek, Zdeněk

2014-01-01

Roč. 5, č. 2 (2014), s. 135-138 ISSN 1877-959X Institutional support: RVO:68081766 Keywords : Ixodes ricinus * Anaplasma phagocytophilum * Rickettsia spp. * Rickettsia helvetica * Rickettsia monacensis * Candidatus Neoehrlichia mikurensis Subject RIV: EE - Microbiology, Virology Impact factor: 2.718, year: 2014

Molecular diagnosis of Rickettsia infection in patients from Tunisia.

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Khrouf, Fatma; Sellami, Hanene; Elleuch, Emna; Hattab, Zouhour; Ammari, Lamia; Khalfaoui, Moncef; Souissi, Jihed; Harrabi, Hejer; M'ghirbi, Youmna; Tiouiri, Hanene; Ben Jemaa, Mounir; Hammami, Adnene; Letaief, Amel; Bouattour, Ali; Znazen, Abir

2016-07-01

Diagnosis of rickettsioses had largely benefited from the development of molecular techniques. Unfortunately, in Tunisia, despite the large number of rickettsial cases registered every year, the Rickettsia species remain unidentified. In this study, we aimed to detect the Rickettsia species in clinical samples using molecular tests. A study was established to analyze skin biopsies, cutaneous swabs, and cerebrospinal fluid samples taken from clinically suspected patients to have rickettsial infection. Two molecular techniques were used to detect Rickettsia DNA: quantitative real time PCR (qPCR) and reverse line blot test (RLB). An analysis of the RLB hybridization assay results revealed the presence of Rickettsia DNA in skin biopsies (40.6%) and swabs (46.7%). Rickettsia conorii was the most prevalent identified species among tested samples. Other species of interest include Rickettsia typhi and Rickettsia massiliae. Using qPCR positivity rates in skin biopsies was 63.7% against 80% in swabs. R. conorii was the most frequently detected species, followed by R. typhi. The agreement between the two techniques was 68.6% (kappa=0.33). Molecular tests, especially using specific probes qPCR, allow for a rapid, better and confident diagnosis in clinical practice. They improve the survey of Mediterranean spotted fever which is considered to be the most important rickettsial infection in humans in Tunisia. Copyright © 2016 Elsevier GmbH. All rights reserved.

Detection of Rickettsia and Anaplasma from hard ticks in Thailand.

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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. © 2015 The Society for Vector Ecology.

Comparative vertical transmission of Rickettsia by Dermacentor variabilis and Amblyomma maculatum.

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Harris, Emma K; Verhoeve, Victoria I; Banajee, Kaikhushroo H; Macaluso, Jacqueline A; Azad, Abdu F; Macaluso, Kevin R

2017-06-01

The geographical overlap of multiple Rickettsia and tick species coincides with the molecular detection of a variety of rickettsial agents in what may be novel tick hosts. However, little is known concerning transmissibility of rickettsial species by various tick hosts. To examine the vertical transmission potential between select tick and rickettsial species, two sympatric species of ticks, Dermacentor variabilis and Amblyomma maculatum, were exposed to five different rickettsial species, including Rickettsia rickettsii, Rickettsia parkeri, Rickettsia montanensis, Rickettsia amblyommatis, or flea-borne Rickettsia felis. Fitness-related metrics including engorgement weight, egg production index, nutrient index, and egg hatch percentage were then assessed. Subsamples of egg clutches and unfed larvae, nymphs, and adults for each cohort were assessed for transovarial and transstadial transmission of rickettsiae by qPCR. Rickettsial exposure had a minimal fitness effect in D. variabilis and transovarial transmission was observed for all groups except R. rickettsii. In contrast, rickettsial exposure negatively influenced A. maculatum fitness and transovarial transmission of rickettsiae was demonstrated only for R. amblyommatis- and R. parkeri-exposed ticks. Sustained maintenance of rickettsiae via transstadial transmission was diminished from F 1 larvae to F 1 adults in both tick species. The findings of this study suggest transovarial transmission specificity may not be tick species dependent, and sustained vertical transmission is not common. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Rickettsia bellii, Rickettsia amblyommii, and Laguna Negra hantavirus in an Indian reserve in the Brazilian Amazon

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de Barros Lopes, Lívia; Guterres, Alexandro; Rozental, Tatiana; Carvalho de Oliveira, Renata; Mares-Guia, Maria Angélica; Fernandes, Jorlan; Figueredo, José Ferreira; Anschau, Inês; de Jesus, Sebastião; V Almeida, Ana Beatriz M; Cristina da Silva, Valéria; Gomes de Melo Via, Alba Valéria; Bonvicino, Cibele Rodrigues; D’Andrea, Paulo Sérgio; Barreira, Jairo Dias

2014-01-01

Background The purpose of this study was to identify the presence of rickettsia and hantavirus in wild rodents and arthropods in response to an outbreak of acute unidentified febrile illness among Indians in the Halataikwa Indian Reserve, northwest of the Mato Grosso state, in the Brazilian Amazon. Where previously surveillance data showed serologic evidence of rickettsia and hantavirus human infection. Methods The arthropods were collected from the healthy Indian population and by flagging v...

Rickettsia parkeri in Gulf Coast Ticks, Southeastern Virginia, USA

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2011-05-01

Rickettsia parkeri in Gulf Coast Ticks, Southeastern Virginia, USA Chelsea L. Wright, Robyn M. Nadolny, Ju Jiang, Allen L. Richards, Daniel E...Virginia. We found that 43.1% of the adult Gulf Coast ticks collected in the summer of 2010 carried Rickettsia parkeri, suggesting that persons living in...or visiting southeastern Virginia are at risk for infection with this pathogen. Rickettsia parkeri is an obligate intracellular bacterium belonging

Horizontal transmission of the insect symbiont Rickettsia is plant-mediated

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

2012-01-01

Bacteria in the genus Rickettsia, best known as vertebrate pathogens vectored by blood-feeding arthropods, can also be found in phytophagous insects. The presence of closely related bacterial symbionts in evolutionarily distant arthropod hosts presupposes a means of horizontal transmission, but no mechanism for this transmission has been described. Using a combination of experiments with live insects, molecular analyses and microscopy, we found that Rickettsia were transferred from an insect host (the whitefly Bemisia tabaci) to a plant, moved inside the phloem, and could be acquired by other whiteflies. In one experiment, Rickettsia was transferred from the whitefly host to leaves of cotton, basil and black nightshade, where the bacteria were restricted to the phloem cells of the plant. In another experiment, Rickettsia-free adult whiteflies, physically segregated but sharing a cotton leaf with Rickettsia-plus individuals, acquired the Rickettsia at a high rate. Plants can serve as a reservoir for horizontal transmission of Rickettsia, a mechanism which may explain the occurrence of phylogenetically similar symbionts among unrelated phytophagous insect species. This plant-mediated transmission route may also exist in other insect–symbiont systems and, since symbionts may play a critical role in the ecology and evolution of their hosts, serve as an immediate and powerful tool for accelerated evolution. PMID:22113034

Development of shuttle vectors for transformation of diverse Rickettsia species.

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Nicole Y Burkhardt

Full Text Available Plasmids have been identified in most species of Rickettsia examined, with some species maintaining multiple different plasmids. Three distinct plasmids were demonstrated in Rickettsia amblyommii AaR/SC by Southern analysis using plasmid specific probes. Copy numbers of pRAM18, pRAM23 and pRAM32 per chromosome in AaR/SC were estimated by real-time PCR to be 2.0, 1.9 and 1.3 respectively. Cloning and sequencing of R. amblyommii AaR/SC plasmids provided an opportunity to develop shuttle vectors for transformation of rickettsiae. A selection cassette encoding rifampin resistance and a fluorescent marker was inserted into pRAM18 yielding a 27.6 kbp recombinant plasmid, pRAM18/Rif/GFPuv. Electroporation of Rickettsia parkeri and Rickettsia bellii with pRAM18/Rif/GFPuv yielded GFPuv-expressing rickettsiae within 2 weeks. Smaller vectors, pRAM18dRG, pRAM18dRGA and pRAM32dRGA each bearing the same selection cassette, were made by moving the parA and dnaA-like genes from pRAM18 or pRAM32 into a vector backbone. R. bellii maintained the highest numbers of pRAM18dRGA (13.3 - 28.1 copies, and R. parkeri, Rickettsia monacensis and Rickettsia montanensis contained 9.9, 5.5 and 7.5 copies respectively. The same species transformed with pRAM32dRGA maintained 2.6, 2.5, 3.2 and 3.6 copies. pRM, the plasmid native to R. monacensis, was still present in shuttle vector transformed R. monacensis at a level similar to that found in wild type R. monacensis after 15 subcultures. Stable transformation of diverse rickettsiae was achieved with a shuttle vector system based on R. amblyommii plasmids pRAM18 and pRAM32, providing a new research tool that will greatly facilitate genetic and biological studies of rickettsiae.

First report of a Rickettsia asembonensis related infecting fleas in Brazil.

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Silva, Arannadia Barbosa; Vizzoni, Vinicius Figueiredo; Costa, Andréa Pereira; Costa, Francisco Borges; Moraes-Filho, Jonas; Labruna, Marcelo Bahia; Gazêta, Gilberto Salles; de Maria Seabra Nogueira, Rita

2017-08-01

The present study was performed in a non-endemic area for spotted fever (SF) in Imperatriz microregion, state of Maranhão, Brazil. Blood samples and ectoparasites were collected from 300 dogs of the Imperatriz microregion. Canine serum samples were tested individually by indirect immunofluorescence assay (IFA), using five Rickettsia isolates from Brazil. Antibodies reactive to at least one of the five species of Rickettsia were detected in 1.6% of the dogs (5/300). These sera were considered reactive to Rickettsia rickettsii and Rickettsia amblyommatis or very closely related species. The ticks (Acari: Ixodidae), identified as Rhipicephalus sanguineus sensu lato (Latreille), and the fleas, identified as Ctenocephalides felis, were tested by polymerase chain reaction (PCR) for detection of rickettsial DNA. More than 78% (83/106) of the C. felis fleas were found to be infected with Rickettsia species using gltA as rickettsial PCR targets, whereas no evidence of Rickettsia spp. was found in R. sanguineus s. l. Genetic analysis based on genes gltA, htrA and ompB showed that the detected strain, is most closely related to Rickettsia asembonensis (formerly Candidatus Rickettsia asemboensis). The present study is the first report of a R. asembonensis related infecting C. felis fleas in Brazil. Copyright © 2017 Elsevier B.V. All rights reserved.

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

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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

Rickettsia amblyommatis infecting ticks and exposure of domestic dogs to Rickettsia spp. in an Amazon-Cerrado transition region of northeastern Brazil.

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Costa, Francisco B; da Costa, Andréa P; Moraes-Filho, Jonas; Martins, Thiago F; Soares, Herbert S; Ramirez, Diego G; Dias, Ricardo A; Labruna, Marcelo B

2017-01-01

This study was performed in Maranhão state, a transition area two Brazilian biomes, Amazon and Cerrado. During 2011-2013, 1,560 domestic dogs were sampled for collection of serum blood samples and ticks in eight counties (3 within the Amazon and 5 within the Cerrado). A total of 959 ticks were collected on 150 dogs (9.6%). Rhipicephalus sanguineus sensu lato (s.l.) was the most abundant tick (68% of all collected specimens), followed by Amblyomma cajennense sensu lato (s.l.) (12.9%), Amblyomma parvum (9.2%), and Amblyomma ovale (5.2%). Other less abundant species (Rickettsia species: Rickettsia amblyommatis in 1% (1/100) A. cajennense s.l., 'Candidatus Rickettsia andeanae' in 20.7% (12/58) A. parvum, Rickettsia bellii in 6.8% (3/44) A. ovale and 100% (1/1) A. rotundatum ticks. An additional collection of A. sculptum from horses in a Cerrado area, and A. cajennense s.s. from pigs in an Amazon area revealed R. amblyommatis infecting only the A. cajennense s.s. ticks. Serological analysis of the 1,560 canine blood samples revealed 12.6% canine seroreactivity to Rickettsia spp., with the highest specific seroreactivity rate (10.2%) for R. amblyommatis. Endpoint titers to R. amblyommatis were significantly higher than those for the other Rickettsia antigens, suggesting that most of the seroreactive dogs were exposed to R. amblyommatis-infected ticks. Highest canine seroreactivity rates per locality (13.1-30.8%) were found in Amazon biome, where A. cajennense s.s. predominated. Lowest seroreactivity rates (1.9-6.5%) were found in Cerrado localities that were further from the Amazon, where A. sculptum predominated. Multivariate analyses revealed that canine seroreactivity to Rickettsia spp. or R. amblyommatis was statistically associated with rural dogs, exposed to Amblyomma ticks.

A retrospective study of the characterization of Rickettsia species in ticks collected from humans.

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Blanda, Valeria; Torina, Alessandra; La Russa, Francesco; D'Agostino, Rosalia; Randazzo, Kety; Scimeca, Salvatore; Giudice, Elisabetta; Caracappa, Santo; Cascio, Antonio; de la Fuente, José

2017-06-01

Rickettsiae (family Rickettsiaceae, order Rickettsiales) are obligate intracellular bacteria transmitted by arthropod vectors. Several Rickettsia species causing vector-borne rickettsioses belong to the spotted fever group (SFG). Traditionally, Rickettsia conorii has been considered as the main etiologic agent of Mediterranean spotted fever. However, the molecular characterization of rickettsiae allowed identifying other species involved in spotted fever in the Mediterranean region. In this study, 42 ticks collected from humans were subjected to morphological identification and molecular characterization of Rickettsia species potentially involved in human rickettsiosis in Sicily. Fourteen ticks positive to at least two Rickettsia spp. molecular markers were used in the study. Identified Rickettsia spp. included R. conorii, found in Rhipicephalus sanguineus sensu lato and Rhipicephalus turanicus, Rickettsia aeschlimannii found in Hyalomma marginatum, Hyalomma lusitanicum, Dermacentor marginatus and Ixodes ricinus, Rickettsia massiliae found in R. turanicus and R. sanguineus s.l., and Rickettsia slovaca found in D. marginatus and R. sanguineus s.l. Our results showed a great variety of zoonotic Rickettsia spp. in ticks collected from humans in Sicily. The Rickettsia spp. reported in this study were identified in previously recognized or new potential tick vectors in Europe, highlighting the risk of infection by different Rickettsia spp. for humans bitten by ticks in Sicily. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Possible Rickettsia massiliae Infection in Greece: an Imported Case.

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Chochlakis, Dimosthenis; Bongiorni, Christine; Partalis, Nikolaos; Tselentis, Yannis; Psaroulaki, Anna

2016-07-22

Tick-borne rickettsioses are endemic in Greece; however, until recently, only Rickettsia typhi and R. conorii were tested routinely in human samples arriving at the National Reference Center. During the last few years, the identification of different rickettsia species in ticks led to the introduction of other spotted fever group rickettsiae in routine analysis. Under the new scheme, R. massiliae is now tested routinely in human samples; herein, we describe a human case of this infection.

Molecular Evidence of Different Rickettsia Species in Villeta, Colombia.

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Faccini-Martínez, Álvaro A; Ramírez-Hernández, Alejandro; Forero-Becerra, Elkin; Cortés-Vecino, Jesús A; Escandón, Patricia; Rodas, Juan D; Palomar, Ana M; Portillo, Aránzazu; Oteo, José A; Hidalgo, Marylin

2016-02-01

The aim of this work was to detect and identify Rickettsia species in ticks collected in rural areas of Villeta, Colombia. Tick specimens were collected from domestic animals and walls of houses in five rural villages of Villeta town and from humans in Naranjal village (same town). Moreover, a flea collected from the same area was also processed. DNA was extracted and tested by conventional, semi-nested, and nested PCR reactions targeting rickettsial genes. In the ticks collected from humans from Naranjal village, a nymph of Amblyomma cajennense sensu lato was amplified using primers for ompA and sequenced (100% identity with "Candidatus Rickettsia amblyommii"). Last, three amplicons from the Ctenocephalides felis flea, corresponding to gltA, ompB, and 16S rRNA genes, showed high identity with R. felis (98.5%, 97.3%, and 99.2%, respectively) and "Candidatus Rickettsia asemboensis" (99.7% and 100%, respectively). To our knowledge, these results correspond to the first molecular detection in Colombia of "Candidatus Rickettsia amblyommii" and "Ca. Rickettsia asemboensis" in fleas.

In vitro studies of Rickettsia-host cell interactions: Confocal laser scanning microscopy of Rickettsia helvetica-infected eukaryotic cell lines.

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Speck, Stephanie; Kern, Tanja; Aistleitner, Karin; Dilcher, Meik; Dobler, Gerhard; Essbauer, Sandra

2018-02-01

Rickettsia (R.) helvetica is the most prevalent rickettsia found in Ixodes ricinus ticks in Germany. Several studies reported antibodies against R. helvetica up to 12.5% in humans investigated, however, fulminant clinical cases are rare indicating a rather low pathogenicity compared to other rickettsiae. We investigated growth characteristics of R. helvetica isolate AS819 in two different eukaryotic cell lines with focus on ultra-structural changes of host cells during infection determined by confocal laser scanning microscopy. Further investigations included partially sequencing of rickA, sca4 and sca2 genes, which have been reported to encode proteins involved in cell-to-cell spread and virulence in some rickettsiae. R. helvetica grew constantly but slowly in both cell lines used. Confocal laser scanning microscopy revealed that the dissemination of R. helvetica AS819 in both cell lines was rather mediated by cell break-down and bacterial release than cell-to-cell spread. The cytoskeleton of both investigated eukaryotic cell lines was not altered. R. helvetica possesses rickA, but its expression is not sufficient to promote actin-based motility as demonstrated by confocal laser scanning microscopy. Hypothetical Sca2 and Sca4 proteins were deduced from nucleotide gene sequences but the predicted amino acid sequences were disrupted or truncated compared to other rickettsiae most likely resulting in non-functional proteins. Taken together, these results might give a first hint to the underlying causes of the reduced virulence and pathogenicity of R. helvetica.

Challenges posed by tick-borne rickettsiae: eco-epidemiology and public health implications.

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Eremeeva, Marina E; Dasch, Gregory A

2015-01-01

Rickettsiae are obligately intracellular bacteria that are transmitted to vertebrates by a variety of arthropod vectors, primarily by fleas and ticks. Once transmitted or experimentally inoculated into susceptible mammals, some rickettsiae may cause febrile illness of different morbidity and mortality, and which can manifest with different types of exhanthems in humans. However, most rickettsiae circulate in diverse sylvatic or peridomestic reservoirs without having obvious impacts on their vertebrate hosts or affecting humans. We have analyzed the key features of tick-borne maintenance of rickettsiae, which may provide a deeper basis for understanding those complex invertebrate interactions and strategies that have permitted survival and circulation of divergent rickettsiae in nature. Rickettsiae are found in association with a wide range of hard and soft ticks, which feed on very different species of large and small animals. Maintenance of rickettsiae in these vector systems is driven by both vertical and horizontal transmission strategies, but some species of Rickettsia are also known to cause detrimental effects on their arthropod vectors. Contrary to common belief, the role of vertebrate animal hosts in maintenance of rickettsiae is very incompletely understood. Some clearly play only the essential role of providing a blood meal to the tick while other hosts may supply crucial supplemental functions for effective agent transmission by the vectors. This review summarizes the importance of some recent findings with known and new vectors that afford an improved understanding of the eco-epidemiology of rickettsiae; the public health implications of that information for rickettsial diseases are also described. Special attention is paid to the co-circulation of different species and genotypes of rickettsiae within the same endemic areas and how these observations may influence, correctly or incorrectly, trends, and conclusions drawn from the surveillance of

Rickettsia species in fleas collected from small mammals in Slovakia.

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Špitalská, Eva; Boldiš, Vojtech; Mošanský, Ladislav; Sparagano, Olivier; Stanko, Michal

2015-11-01

Epidemiological and epizootiological studies of Rickettsia felis and other Rickettsia spp. are very important, because their natural cycle has not yet been established completely. In total, 315 fleas (Siphonaptera) of 11 species of Ceratophyllidae, Hystrichopsyllidae and Leptopsyllidae families were tested for the presence of Rickettsia species and Coxiella burnetii with conventional and specific quantitative real-time PCR assays. Fleas were collected from five rodent hosts (Myodes glareolus, Apodemus flavicollis, Apodemus agrarius, Microtus subterraneus, Microtus arvalis) and three shrew species (Sorex araneus, Neomys fodiens, Crocidura suaveolens) captured in Eastern and Southern Slovakia. Overall, Rickettsia spp. was found in 10.8% (34/315) of the tested fleas of Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus uncinatus and Nosopsyllus fasciatus species. Infected fleas were coming from A. flavicollis, A. agrarius, and M. glareolus captured in Eastern Slovakia. C. burnetii was not found in any fleas. R. felis, Rickettsia helvetica, unidentified Rickettsia, and rickettsial endosymbionts were identified in fleas infesting small mammals in the Košice region, Eastern Slovakia. This study is the first report of R. felis infection in C. solutus male flea collected from A. agrarius in Slovakia.

Rickettsia Species in African Anopheles Mosquitoes

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Socolovschi, Cristina; Pages, Frédéric; Ndiath, Mamadou O.; Ratmanov, Pavel; Raoult, Didier

2012-01-01

Background There is higher rate of R. felis infection among febrile patients than in healthy people in Sub-Saharan Africa, predominantly in the rainy season. Mosquitoes possess a high vectorial capacity and, because of their abundance and aggressiveness, likely play a role in rickettsial epidemiology. Methodology/Principal Findings Quantitative and traditional PCR assays specific for Rickettsia genes detected rickettsial DNA in 13 of 848 (1.5%) Anopheles mosquitoes collected from Côte d’Ivoire, Gabon, and Senegal. R. felis was detected in one An. gambiae molecular form S mosquito collected from Kahin, Côte d’Ivoire (1/77, 1.3%). Additionally, a new Rickettsia genotype was detected in five An. gambiae molecular form S mosquitoes collected from Côte d’Ivoire (5/77, 6.5%) and one mosquito from Libreville, Gabon (1/88, 1.1%), as well as six An. melas (6/67, 9%) mosquitoes collected from Port Gentil, Gabon. A sequence analysis of the gltA, ompB, ompA and sca4 genes indicated that this new Rickettsia sp. is closely related to R. felis. No rickettsial DNA was detected from An. funestus, An. arabiensis, or An. gambiae molecular form M mosquitoes. Additionally, a BLAST analysis of the gltA sequence from the new Rickettsia sp. resulted in a 99.71% sequence similarity to a species (JQ674485) previously detected in a blood sample of a Senegalese patient with a fever from the Bandafassi village, Kedougou region. Conclusion R. felis was detected for the first time in An. gambiae molecular form S, which represents the major African malaria vector. The discovery of R. felis, as well as a new Rickettsia species, in mosquitoes raises new issues with respect to African rickettsial epidemiology that need to be investigated, such as bacterial isolation, the degree of the vectorial capacity of mosquitoes, the animal reservoirs, and human pathogenicity. PMID:23118963

Ticks and rickettsiae from wildlife in Belize, Central America.

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Lopes, Marcos G; May Junior, Joares; Foster, Rebecca J; Harmsen, Bart J; Sanchez, Emma; Martins, Thiago F; Quigley, Howard; Marcili, Arlei; Labruna, Marcelo B

2016-02-02

The agents of spotted fevers in Latin America are Rickettsia rickettsii, R. parkeri, Rickettsia sp. strain Atlantic rainforest, and R. massiliae. In Continental Central America, R. rickettsii remains the only known pathogenic tick-borne rickettsia. In the present study, ticks were collected from wild mammals in natural areas of Belize. Besides providing new data of ticks from Belize, we investigated rickettsial infection in some of these ticks. Our results provide ticks harboring rickettsial agents for the first time in Central America. Between 2010 and 2015, wild mammals were lived-trapped in the tropical broadleaf moist forests of central and southern Belize. Ticks were collected from the animals and identified to species by morphological and molecular analysis (DNA sequence of the tick mitochondrial 16S RNA gene). Some of the ticks were tested for rickettsial infection by molecular methods (DNA sequences of the rickettsial gltA and ompA genes). A total of 84 ticks were collected from 8 individual hosts, as follows: Amblyomma pacae from 3 Cuniculus paca; Amblyomma ovale and Amblyomma coelebs from a Nasua narica; A. ovale from an Eira Barbara; A. ovale, Amblyomma cf. oblongoguttatum, and Ixodes affinis from a Puma concolor; and A. ovale, A. coelebs, A. cf. oblongoguttatum, and I. affinis from two Panthera onca. Three rickettsial agents were detected: Rickettsia amblyommii in A. pacae, Rickettsia sp. strain Atlantic rainforest in A. ovale, and Rickettsia sp. endosymbiont in Ixodes affinis. The present study provides unprecedented records of ticks harboring rickettsial agents in the New World. An emerging rickettsial pathogen of South America, Rickettsia sp. strain Atlantic rainforest, is reported for the first time in Central America. Besides expanding the distribution of 3 rickettsial agents in Central America, our results highlight the possible occurrence of Rickettsia sp. strain Atlantic rainforest-caused spotted fever human cases in Belize, since its possible

Molecular Detection of Rickettsia amblyommii in Amblyomma americanum Parasitizing Humans

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2010-01-01

Detection of Rickettsia amblyommii in Amblyomma americanum Parasitizing Humans Ju Jiang~ Tamasin Yarina~ Melissa K. Miller,2 Ellen Y. Stromdahl? and...protein B gene (ompB) of Rickettsia amblyommii was employed to assess the threat of R. amblyommii exposure to humans parasitized by Amblyomma americanum...infection of and possibly disease in humans. Key Words: Amblyomma americanum-Lone star ticks-Real-time PCR- Rickettsia amblyommii. Introduction R

Diversity of spotted fever group Rickettsia infection in hard ticks from Suifenhe, Chinese-Russian border.

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Cheng, Cheng; Fu, Weiming; Ju, Wendong; Yang, Liwei; Xu, Ning; Wang, Yan-Mei; Li, Hui; Wang, Yan-Lu; Hu, Man-Xia; Wen, Jing; Jiao, Dan; Geng, Cong; Sun, Yi

2016-07-01

In order to investigate the diversity of spotted fever group (SFG) Rickettsia infection in hard ticks, ticks were harvested from the forest areas in Suifenhe city, along the Chinese-Russian border and conventional PCR was carried out using universal SFG Rickettsia primers targeting gltA and ompA genes to screen for their infection with SFG Rickettsia organisms. Results showed that of the 215 ticks belonging to Ixodes persulcatus, Haemaphysalis concinna and Haemaphysalis japonica Warburton, 1908 species, 138 (64.2%) were positive for SFG Rickettsia. Three species of SFG Rickettsia were detected, Rickettsia raoultii, Rickettsia heilongjiangensis and Candidatus Rickettsia tarasevichiae. No co-infection with different species of SFG Rickettsia was found in any individual tick among the three tick species. We detected more than one SFG Rickettsia species in ticks from each of the three tick species with an overlapping distribution and potentially similar transmission cycles of SFG Rickettsia in the areas surveyed. Consequently, different pathogenic rickettsial species may be involved in human cases of rickettsiosis after a bite of the three above-mentioned tick species in that area Rickettsia. Copyright © 2016. Published by Elsevier GmbH.

Experimental infection of Rickettsia parkeri in the Rhipicephalus microplus tick.

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Cordeiro, Matheus Dias; de Azevedo Baêta, Bruna; Cepeda, Patricia Barizon; Teixeira, Rafaella Câmara; Ribeiro, Carla Carolina Dias Uzedo; de Almeida Valim, Jaqueline Rodrigues; Pinter, Adriano; da Fonseca, Adivaldo Henrique

2018-01-01

This study aimed to evaluate, by means of artificial feeding, the interaction between a pathogenic rickettsia and the hard tick R. microplus. We used partially engorged females fed on calves free of Rickettsia spp. Group 1 (G1), containing 20 ticks, was fed bovine blood only. Group 2 (G2), containing 20 ticks, was fed blood containing uninfected VERO cells, and group 3 (G3), containing 40 ticks, was fed blood containing VERO cells infected with Rickettsia parkeri. Biological parameters of the non-parasitic phase and a possible bacterial transmission to the tick eggs and to guinea pigs were evaluated. At the end of oviposition, all G3 females were PCR-positive for genes specific for the genus Rickettsia. Although no guinea pigs were infected, the experimental infection of R. microplus by R. parkeri caused a deleterious effect on the oviposition and provided the first report of transovarian transmission of rickettsia in this tick. Copyright © 2017 Elsevier GmbH. All rights reserved.

Evidencia serológica de infecciones de Rickettsia en humanos provenientes de tres localidades de Panamá

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Sergio E. Bermúdez

2013-08-01

Full Text Available Introducción. Desde mediados del siglo pasado, se conocen en Panamá casos de rickettsiosis, cuando fueron reportados brotes de tifus en ratones y de fiebres manchadas. A partir de entonces, poca información se tiene sobre su prevalencia en este país, lo cual se debe principalmente a que son confundidos con otras enfermedades. Objetivos. El objetivo de este trabajo fue demostrar la presencia de rickettsiosis en humanos provenientes de tres localidades de Panamá, que corresponden a zonas agropecuarias, cercanas a bosques, o que trabajaban en zoológicos. Materiales y métodos. Se escogieron tres localidades para este estudio: Tortí (provincia de Panamá, El Valle de Antón (provincia de Coclé y el Parque Municipal Summit en Ciudad de Panamá. Los voluntarios firmaron un consentimiento informado, además de responder un cuestionario. De cada voluntario se extrajo sangre venosa, la que fue analizada por medio de inmunoflorescencia indirecta, utilizando kits comerciales y láminas sensibilizadas con antígenos cultivados de Rickettsia rickettsii y Rickettsia amblyommii. Resultados. Se tomaron muestras de 97 voluntarios, 25 en Tortí, 37 en El Valle de Antón y 35 en el Parque Municipal Summit. De estos, 38 (39 % de las muestras fueron positivas en algunas de las dos técnicas practicadas: 8 (32 % en Tortí, 18 (48 % en El Valle y 12 (34 % en el Parque Municipal Summit. Conclusión. Se demuestra una alta prevalencia de anticuerpos contra Rickettsia del grupo de las fiebres manchadas en las tres áreas de estudio, además de presentarse evidencia de títulos para Rickettsia del grupo tifus en El Valle de Antón. Estas zonas podrían considerarse como endémicas por rickettsiosis, ya que existen condiciones que permiten el mantenimiento de las mismas. doi: http://dx.doi.org/10.7705/biomedica.v33i0.831

Rickettsia species in human-parasitizing ticks in Greece.

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Papa, Anna; Xanthopoulou, Kyriaki; Kotriotsiou, Tzimoula; Papaioakim, Miltiadis; Sotiraki, Smaragda; Chaligiannis, Ilias; Maltezos, Efstratios

2016-05-01

Ticks serve as vectors and reservoirs for a variety of bacterial, viral and protozoan pathogens affecting humans and animals. Unusual increased tick aggressiveness was observed in 2008-2009 in northeastern Greece. The aim of the study was to check ticks removed from persons during 2009 for infection with Rickettsia species. A total of 159 ticks were removed from 147 persons who sought medical advice in a hospital. Tick identification was performed morphologically using taxonomic keys. DNA was extracted from each individual tick and a PCR assay targeting the rickettsial outer membrane protein A gene of Rickettsia spp. was applied. Most of the adult ticks (132/153, 86.3%) were Rhipicephalus sanguineus. Rickettsiae were detected in 23 of the 153 (15.0%) adult ticks. Five Rickettsiae species were identified: R. aeschlimannii, R. africae (n=6), R. massilae (4), R. monacensis (1), and Candidatus R. barbariae (1). To our knowledge, this is the first report of R. africae, R. monacensis, and Candidatus R. barbariae in Greece. Several Rickettsia species were identified in ticks removed from humans in Greece, including those that are prevalent in northern and southern latitudes. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Detection of spotted fever group (SFG) rickettsiae in Dermacentor reticulatus (Acari: Ixodidae) in Poland.

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Stańczak, Joanna

2006-05-01

Dermacentor reticulatus ticks from Poland were investigated by molecular methods for the presence of rickettsiae. During 2003/2004, a total of 285 adult ticks was assayed using primers RpCS.877 and RpCS.1258 derived from the citrate synthase (gltA) gene, and 116 samples (40.7%) were positive for rickettsial DNA. Ten out of these positive samples were further assayed using SLO1F and SLO1R primers derived form the rOmpA-encoding gene to confirm that detected rickettsiae belong to the spotted fever group (SFG). The obtained sequence of a fragment of the gltA gene of Rickettsia sp. isolated from Polish D. reticulatus demonstrated 96-98% similarities to Rickettsia slovaca, Rickettsia sibirica, Rickettsia honei, and other SFG rickettsiae. The nucleotide sequences of the amplified fragments of the ompA gene were 98% homologous to RpA4 Rickettsia sp. reported from ticks collected in territories of the former Soviet Union.

Permeability of Rickettsia prowazekii to NAD

International Nuclear Information System (INIS)

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

1989-01-01

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

Ixodes pacificus Ticks Maintain Embryogenesis and Egg Hatching after Antibiotic Treatment of Rickettsia Endosymbiont

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Kurlovs, Andre H.; Li, Jinze; Cheng, Du; Zhong, Jianmin

2014-01-01

Rickettsia is a genus of intracellular bacteria that causes a variety of diseases in humans and other mammals and associates with a diverse group of arthropods. Although Rickettsia appears to be common in ticks, most Rickettsia-tick relationships remain generally uncharacterized. The most intimate of these associations is Rickettsia species phylotype G021, a maternally and transstadially transmitted endosymbiont that resides in 100% of I. pacificus in California. We investigated the effects of this Rickettsia phylotype on I. pacificus reproductive fitness using selective antibiotic treatment. Ciprofloxacin was 10-fold more effective than tetracycline in eliminating Rickettsia from I. pacificus, and quantitative PCR results showed that eggs from the ciprofloxacin-treated ticks contained an average of 0.02 Rickettsia per egg cell as opposed to the average of 0.2 in the tetracycline-treated ticks. Ampicillin did not significantly affect the number of Rickettsia per tick cell in adults or eggs compared to the water-injected control ticks. We found no relationship between tick embryogenesis and rickettsial density in engorged I. pacificus females. Tetracycline treatment significantly delayed oviposition of I. pacificus ticks, but the antibiotic’s effect was unlikely related to Rickettsia. We also demonstrated that Rickettsia-free eggs could successfully develop into larvae without any significant decrease in hatching compared to eggs containing Rickettsia. No significant differences in the incubation period, egg hatching rate, and the number of larvae were found between any of the antibiotic-treated groups and the water-injected tick control. We concluded that Rickettsia species phylotype G021 does not have an apparent effect on embryogenesis, oviposition, and egg hatching of I. pacificus. PMID:25105893

First detection of Rickettsia conorii ssp. caspia in Rhipicephalus sanguineus in Zambia.

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Chitimia-Dobler, Lidia; Dobler, Gerhard; Schaper, Sabine; Küpper, Thomas; Kattner, Simone; Wölfel, Silke

2017-11-01

Ticks are important vectors for Rickettsia spp. of the spotted fever group all around the world. Rickettsia conorii is the etiological agent of boutonneuse fever in the Mediterranean region and Africa. Tick identification was based on morphological features and further characterized using the 16S rRNA gene. The ticks were individually tested using pan-Rickettsia real-time-PCR for screening, and 23S-5S intergenic spacer region, 16S rDNA, gltA, sca4, ompB, and ompA genes were used to analyze the Rickettsia positive samples. Rickettsia conorii ssp. caspia was detected in tick collected in Zambia for the first time, thus demonstrating the possibility of the occurrence of human disease, namely Astrakhan fever, due to this Rickettsia ssp. in this region of Africa. The prevalence of R. conorii ssp. caspia was 0.06% (one positive tick out of 1465 tested ticks) and 0.07% (one positive tick out of 1254 tested Rh. sanguineus).

First isolation of Rickettsia monacensis from a patient in South Korea.

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Kim, Yeon-Sook; Choi, Yeon-Joo; Lee, Kyung-Min; Ahn, Kyu-Joong; Kim, Heung-Chul; Klein, Terry; Jiang, Ju; Richards, Allen; Park, Kyung-Hee; Jang, Won-Jong

2017-07-01

A Rickettsia sp. was isolated from the blood of a patient with an acute febrile illness using the shell vial technique; the isolate was named CN45Kr and was identified by molecular assay as Rickettsia monacensis, which was first recognized as a pathogen in Spain. Sequencing analysis showed that the gltA sequence of the isolate was identical to that of Rickettsia sp. IRS3. The ompA-5mp fragment sequence showed 100% identity to those of R. monacensis and Rickettsia sp. In56 and ompA-3pA In56 and 100% identity to that of Rickettsia sp. IRS3. The ompB sequence was found to have 99.9% similarity to that of R. monacensis IrR/Munich. This study confirms the pathogenicity of this agent and provides additional information about its geographic distribution. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

Secretome of obligate intracellular Rickettsia

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Gillespie, Joseph J.; Kaur, Simran J.; Rahman, M. Sayeedur; Rennoll-Bankert, Kristen; Sears, Khandra T.; Beier-Sexton, Magda; Azad, Abdu F.

2014-01-01

The genus Rickettsia (Alphaproteobacteria, Rickettsiales, Rickettsiaceae) is comprised of obligate intracellular parasites, with virulent species of interest both as causes of emerging infectious diseases and for their potential deployment as bioterrorism agents. Currently, there are no effective commercially available vaccines, with treatment limited primarily to tetracycline antibiotics, although others (e.g. josamycin, ciprofloxacin, chloramphenicol, and azithromycin) are also effective. Much of the recent research geared toward understanding mechanisms underlying rickettsial pathogenicity has centered on characterization of secreted proteins that directly engage eukaryotic cells. Herein, we review all aspects of the Rickettsia secretome, including six secretion systems, 19 characterized secretory proteins, and potential moonlighting proteins identified on surfaces of multiple Rickettsia species. Employing bioinformatics and phylogenomics, we present novel structural and functional insight on each secretion system. Unexpectedly, our investigation revealed that the majority of characterized secretory proteins have not been assigned to their cognate secretion pathways. Furthermore, for most secretion pathways, the requisite signal sequences mediating translocation are poorly understood. As a blueprint for all known routes of protein translocation into host cells, this resource will assist research aimed at uniting characterized secreted proteins with their apposite secretion pathways. Furthermore, our work will help in the identification of novel secreted proteins involved in rickettsial ‘life on the inside’. PMID:25168200

Propagation of Arthropod-Borne Rickettsia spp. in Two Mosquito Cell Lines▿

OpenAIRE

Sakamoto, Joyce M.; Azad, Abdu F.

2007-01-01

Rickettsiae are obligate intracellular alphaproteobacteria that include pathogenic species in the spotted fever, typhus, and transitional groups. The development of a standardized cell line in which diverse rickettsiae can be grown and compared would be highly advantageous to investigate the differences among and between pathogenic and nonpathogenic species of rickettsiae. Although several rickettsial species have been grown in tick cells, tick cells are more difficult to maintain and they gr...

Detection and identification of Rickettsia species in Ixodes tick populations from Estonia.

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Katargina, Olga; Geller, Julia; Ivanova, Anna; Värv, Kairi; Tefanova, Valentina; Vene, Sirkka; Lundkvist, Åke; Golovljova, Irina

2015-09-01

A total of 1640 ticks collected in different geographical parts of Estonia were screened for the presence of Rickettsia species DNA by real-time PCR. DNA of Rickettsia was detected in 83 out of 1640 questing ticks with an overall prevalence of 5.1%. The majority of the ticks infected by rickettsiae were Ixodes ricinus (74 of 83), while 9 of the 83 positive ticks were Ixodes persulcatus. For rickettsial species identification, a part of the citrate synthase gltA gene was sequenced. The majority of the positive samples were identified as Rickettsia helvetica (81 out of 83) and two of the samples were identified as Rickettsia monacensis and Candidatus R. tarasevichiae, respectively. Genetic characterization based on the partial gltA gene showed that the Estonian sequences within the R. helvetica, R. monacensis and Candidatus R. tarasevichiae species demonstrated 100% similarity with sequences deposited in GenBank, originating from Rickettsia species distributed over large territories from Europe to Asia. Copyright © 2015 Elsevier GmbH. All rights reserved.

Molecular Detection and Identification of Rickettsia Species in Ixodes pacificus in California

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Phan, Jimmy Ninh; Lu, Casey Roy; Bender, William Garrett; Smoak, Robert Marion

2011-01-01

Abstract We amplified 16S rRNA, gltA, and ompA genes from Ixodes pacificus by polymerase chain reaction. Sequencing, BLAST analysis, and phylogenetic constructions indicated that two Rickettsia phylotypes are present in I. pacificus. While phylotype G021 has high homology to Ixodes scapularis endosymbiotic Rickettsia, phylotype G022 is a deeply branched novel spotted fever group Rickettsia. PMID:21413886

Rickettsia spp. among wild mammals and their respective ectoparasites in Pantanal wetland, Brazil.

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de Sousa, Keyla Carstens Marques; Herrera, Heitor Miraglia; Rocha, Fabiana Lopes; Costa, Francisco Borges; Martins, Thiago Fernandes; Labruna, Marcelo Bahia; Machado, Rosangela Zacarias; André, Marcos Rogério

2018-01-01

The genus Rickettsia comprises obligatory intracellular bacteria, well known to cause zoonotic diseases around the world. The present work aimed to investigate the occurrence of Rickettsia spp. in wild animals, domestic dogs and their respective ectoparasites in southern Pantanal region, central-western Brazil, by molecular and serological techniques. Between August 2013 and March 2015, serum, whole blood and/or spleen samples were collected from 31 coatis, 78 crab-eating foxes, seven ocelots, 42 dogs, 110 wild rodents, and 30 marsupials. Serum samples from canids, felids, rodents and marsupials were individually tested by indirect fluorescent antibody test (IFAT) in order to detect IgG antibodies to Rickettsia rickettsii, Rickettsia parkeri and Rickettsia amblyommatis. DNA samples from mammals and ectoparasites were submitted to a multiplex qPCR assay in order to detect and quantify spotted fever group (SFG) and typhus group (TG) rickettsiae and Orientia tsutsugamushi. Positive samples in qPCR assays were submitted to conventional PCR assays targeting gltA, ompA, ompB and htrA genes, followed by sequencing and phylogenetic analyses. The ticks collected (1582) from animals belonged to the species Amblyomma sculptum, Amblyomma parvum, Amblyomma ovale, Amblyomma tigrinum, Rhipicephalus (Boophilus) microplus, Rhipicephalus sanguineus sensu lato and Amblyomma auricularium. Overall, 27 (64.2%) dogs, 59 (75.6%) crab-eating foxes and six (85.7%) ocelots were seroreactive (titer≥64) to at least one Rickettsia species. For 17 (40.4%) dogs, 33 (42.3%) crab-eating foxes, and two (33.3%) ocelots, homologous reactions to R. amblyommatis or a closely related organism were suggested. One hundred and sixteen (23.5%) tick samples and one (1.2%) crab-eating fox blood sample showed positivity in qPCR assays for SFG Rickettsia spp. Among SFG Rickettsia-positive ticks samples, 93 (80.2%) belonged to A. parvum, 14 (12%) belonged to A. sculptum species, three (2.5%) belonged to A

Wholly Rickettsia! Reconstructed Metabolic Profile of the Quintessential Bacterial Parasite of Eukaryotic Cells.

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Driscoll, Timothy P; Verhoeve, Victoria I; Guillotte, Mark L; Lehman, Stephanie S; Rennoll, Sherri A; Beier-Sexton, Magda; Rahman, M Sayeedur; Azad, Abdu F; Gillespie, Joseph J

2017-09-26

Reductive genome evolution has purged many metabolic pathways from obligate intracellular Rickettsia ( Alphaproteobacteria ; Rickettsiaceae ). While some aspects of host-dependent rickettsial metabolism have been characterized, the array of host-acquired metabolites and their cognate transporters remains unknown. This dearth of information has thwarted efforts to obtain an axenic Rickettsia culture, a major impediment to conventional genetic approaches. Using phylogenomics and computational pathway analysis, we reconstructed the Rickettsia metabolic and transport network, identifying 51 host-acquired metabolites (only 21 previously characterized) needed to compensate for degraded biosynthesis pathways. In the absence of glycolysis and the pentose phosphate pathway, cell envelope glycoconjugates are synthesized from three imported host sugars, with a range of additional host-acquired metabolites fueling the tricarboxylic acid cycle. Fatty acid and glycerophospholipid pathways also initiate from host precursors, and import of both isoprenes and terpenoids is required for the synthesis of ubiquinone and the lipid carrier of lipid I and O-antigen. Unlike metabolite-provisioning bacterial symbionts of arthropods, rickettsiae cannot synthesize B vitamins or most other cofactors, accentuating their parasitic nature. Six biosynthesis pathways contain holes (missing enzymes); similar patterns in taxonomically diverse bacteria suggest alternative enzymes that await discovery. A paucity of characterized and predicted transporters emphasizes the knowledge gap concerning how rickettsiae import host metabolites, some of which are large and not known to be transported by bacteria. Collectively, our reconstructed metabolic network offers clues to how rickettsiae hijack host metabolic pathways. This blueprint for growth determinants is an important step toward the design of axenic media to rescue rickettsiae from the eukaryotic cell. IMPORTANCE A hallmark of obligate intracellular

Guidelines for the Detection of Rickettsia spp.

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Portillo, Aránzazu; de Sousa, Rita; Santibáñez, Sonia; Duarte, Ana; Edouard, Sophie; Fonseca, Isabel P; Marques, Cátia; Novakova, Marketa; Palomar, Ana M; Santos, Marcos; Silaghi, Cornelia; Tomassone, Laura; Zúquete, Sara; Oteo, José A

2017-01-01

The genus Rickettsia (Rickettsiales: Rickettsiaceae) includes Gram-negative, small, obligate intracellular, nonmotile, pleomorphic coccobacilli bacteria transmitted by arthropods. Some of them cause human and probably also animal disease (life threatening in some patients). In these guidelines, we give clinical practice advices (microscopy, serology, molecular tools, and culture) for the microbiological study of these microorganisms in clinical samples. Since in our environment rickettsioses are mainly transmitted by ticks, practical information for the identification of these arthropods and for the study of Rickettsia infections in ticks has also been added.

Detection of a Novel Rickettsia From Leptotrombidium scutellare Mites (Acari: Trombiculidae) From Shandong of China.

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Huang, Yuting; Zhao, Li; Zhang, Zhentang; Liu, Miaomiao; Xue, Zaifeng; Ma, Dongqiang; Sun, Xifeng; Sun, Yue; Zhou, Chuanmin; Qin, Xiangrong; Zhu, Yelei; Li, Wenqian; Yu, Hao; Yu, Xue-Jie

2017-05-01

Leptotrombidium scutellare mites, the vector of Orientia tsutsugamushi, have rarely been reported to associate with Rickettsia species. Three hundred nineteen chiggers were collected from the ears of 32 rodents captured in Huangdao District of Qingdao City, China, in October 2015. The chigger samples were tested for Rickettsia, severe fever with thrombocytopenia syndrome virus, and hantavirus by PCR or RT-PCR amplification. All mites were classified morphologically and molecularly as L. scutellare chiggers. Rickettsial DNA sequences were amplified for four genes including 16S rRNA, ompB, gltA, and 17 kD protein genes. The minimum infection rate (MIR; number of positive pools/total specimens tested) of the Rickettsia species in the chiggers were 2.8% (9/319). Phylogenetic analysis indicated that individual genes were closely related to different Rickettsia species including R. felis (with 16S rRNA gene), R. australis (with gltA gene), an unnamed Rickettsia sp. TwKM02 (with ompB gene), and Rickettsia endosymbiont of soft tick Ornithodoros erraticus (with 17 kD protein gene). Phylogenic analysis of the concatenated sequence of 16S rRNA, gltA, ompB, and 17 kD protein genes indicated that the Rickettsia species from L. scutellare chigger was most closely related to R. australis and R. akari. These results indicated that the Rickettsia species in chiggers was unique; it was named Candidatus Rickettsia leptotrombidium. Severe fever with thrombocytopenia syndrome virus and hantavirus were not amplified from the chiggers, suggesting lack of infection of these pathogens in the chiggers. A unique Rickettsia species was detected in L. scutellare, which expanded the knowledge on the vector distribution of Rickettsia. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Dynamics of actin-based movement by Rickettsia rickettsii in vero cells.

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Heinzen, R A; Grieshaber, S S; Van Kirk, L S; Devin, C J

1999-08-01

Actin-based motility (ABM) is a virulence mechanism exploited by invasive bacterial pathogens in the genera Listeria, Shigella, and Rickettsia. Due to experimental constraints imposed by the lack of genetic tools and their obligate intracellular nature, little is known about rickettsial ABM relative to Listeria and Shigella ABM systems. In this study, we directly compared the dynamics and behavior of ABM of Rickettsia rickettsii and Listeria monocytogenes. A time-lapse video of moving intracellular bacteria was obtained by laser-scanning confocal microscopy of infected Vero cells synthesizing beta-actin coupled to green fluorescent protein (GFP). Analysis of time-lapse images demonstrated that R. rickettsii organisms move through the cell cytoplasm at an average rate of 4.8 +/- 0.6 micrometer/min (mean +/- standard deviation). This speed was 2.5 times slower than that of L. monocytogenes, which moved at an average rate of 12.0 +/- 3.1 micrometers/min. Although rickettsiae moved more slowly, the actin filaments comprising the actin comet tail were significantly more stable, with an average half-life approximately three times that of L. monocytogenes (100.6 +/- 19.2 s versus 33.0 +/- 7.6 s, respectively). The actin tail associated with intracytoplasmic rickettsiae remained stationary in the cytoplasm as the organism moved forward. In contrast, actin tails of rickettsiae trapped within the nucleus displayed dramatic movements. The observed phenotypic differences between the ABM of Listeria and Rickettsia may indicate fundamental differences in the mechanisms of actin recruitment and polymerization.

THE DISTRIBUTION OF RICKETTSIA IN THE TISSUES OF INSECTS AND ARACHNIDS.

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Cowdry, E V

1923-03-31

In the absence of a satisfactory definition of Rickettsia the observations herein recorded were arbitrarily limited to bacterium-like organisms which are intracellular and Gram-negative. Rickettsia of this type were found in the following species: Amblyomma americana, Amblyomma hebraeum, Boophilus decoloratus, Atomus sp., Casinaria infesta, Chrysopa oculata, Ctenocephalus canis, Dermacentor variabilis, Lepisma saccharina, Lucoppia curviseta, Margaropus annulatus, Margaropus annulatus australis, Ornithodoros turicata, Pulex irritans, Rhipicephalus sanguineus, Rhipicephalus evertsi, and Salticus scenicus. Since intracellular, Gram-negative Rickettsia have been recorded in the literature as existing in Cimex lectularius, Dermacentor venustus, Melophagus ovinus, and Pediculus humanus, the occasional occurrence of such bodies must be conceded in the following groups not closely related phylogenetically: Attidae, Trombidiidae, Argasidae, lxodidae, Cinura, Acanthiidae, Pediculidae, Hippoboscidae, Chrysopidae, Pulicidae, and Ichneumonidae. The species which harbor Rickettsia differ widely in diet and habitat. One such species is insectivorous throughout life, two are insectivorous in larval stages, becoming vegetarian in the adult condition, one is chiefly vegetarian but partakes of some animal products, and two are usually entirely vegetarian; while the remainder subsist wholly upon a diet of mammalian blood. Rickettsia are associated, in only a few cases, with diseases in mammals. The evidence at hand does not lead beyond the conclusion that the Rickettsia mentioned above are true Gram-negative microorganisms, easily distinguishable from mitochondria and all other cytoplasmic and nuclear granulations, rather completely adapted to an intracellular existence, exhibiting in some cases a remarkable degree of host specificity, and often inherited through the eggs.

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

International Nuclear Information System (INIS)

Rikihisa, Y.; Rota, T.; Lee, T.H.; MacDonald, A.B.; Ito, S.

1979-01-01

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

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

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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. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Rickettsia phylogenomics: unwinding the intricacies of obligate intracellular life.

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Joseph J Gillespie

Full Text Available BACKGROUND: Completed genome sequences are rapidly increasing for Rickettsia, obligate intracellular alpha-proteobacteria responsible for various human diseases, including epidemic typhus and Rocky Mountain spotted fever. In light of phylogeny, the establishment of orthologous groups (OGs of open reading frames (ORFs will distinguish the core rickettsial genes and other group specific genes (class 1 OGs or C1OGs from those distributed indiscriminately throughout the rickettsial tree (class 2 OG or C2OGs. METHODOLOGY/PRINCIPAL FINDINGS: We present 1823 representative (no gene duplications and 259 non-representative (at least one gene duplication rickettsial OGs. While the highly reductive (approximately 1.2 MB Rickettsia genomes range in predicted ORFs from 872 to 1512, a core of 752 OGs was identified, depicting the essential Rickettsia genes. Unsurprisingly, this core lacks many metabolic genes, reflecting the dependence on host resources for growth and survival. Additionally, we bolster our recent reclassification of Rickettsia by identifying OGs that define the AG (ancestral group, TG (typhus group, TRG (transitional group, and SFG (spotted fever group rickettsiae. OGs for insect-associated species, tick-associated species and species that harbor plasmids were also predicted. Through superimposition of all OGs over robust phylogeny estimation, we discern between C1OGs and C2OGs, the latter depicting genes either decaying from the conserved C1OGs or acquired laterally. Finally, scrutiny of non-representative OGs revealed high levels of split genes versus gene duplications, with both phenomena confounding gene orthology assignment. Interestingly, non-representative OGs, as well as OGs comprised of several gene families typically involved in microbial pathogenicity and/or the acquisition of virulence factors, fall predominantly within C2OG distributions. CONCLUSION/SIGNIFICANCE: Collectively, we determined the relative conservation and

Development of a Novel Loop-Mediated Isothermal Amplification (LAMP) Assay for the Detection of Rickettsia spp.

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Hanaoka, Nozomu; Matsutani, Minenosuke; Satoh, Masaaki; Ogawa, Motohiko; Shirai, Mutsunori; Ando, Shuji

2017-01-24

We developed a novel loop-mediated isothermal amplification (LAMP) method to detect Rickettsia spp., including Rickettsia prowazekii and R. typhi. Species-specific LAMP primers were developed for orthologous genes conserved among Rickettsia spp. The selected modified primers could detect all the Rickettsia spp. tested. The LAMP method was successfully used to detect 100 DNA copies of Rickettsia spp. within approximately 60 min at 63℃. Therefore, this method may be an excellent tool for the early diagnosis of rickettsiosis in a laboratory or in the field.

Detection of Rickettsia in Rhipicephalus sanguineus Ticks and Ctenocephalides felis Fleas from Southeastern Tunisia by Reverse Line Blot Assay

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Khrouf, Fatma; M'Ghirbi, Youmna; Znazen, Abir; Ben Jemaa, Mounir; Hammami, Adnene

2014-01-01

Ticks (n = 663) and fleas (n = 470) collected from domestic animals from southeastern Tunisia were screened for Rickettsia infection using reverse line blot assay. Evidence of spotted fever group Rickettsia was obtained. We detected Rickettsia felis in fleas, Rickettsia massiliae Bar 29 and the Rickettsia conorii Israeli spotted fever strain in ticks, and Rickettsia conorii subsp. conorii and Rickettsia spp. in both arthropods. The sensitivity of the adopted technique allowed the identification of a new association between fleas and R. conorii subsp. conorii species. The presence of these vector-borne Rickettsia infections should be considered when diagnosing this disease in humans in Tunisia. PMID:24226919

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

Science.gov (United States)

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

2014-10-01

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.

Molecular Detection of Rickettsia Species Within Ticks (Acari: Ixodidae) Collected from Arkansas United States.

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Trout Fryxell, R T; Steelman, C D; Szalanski, A L; Billingsley, P M; Williamson, P C

2015-05-01

Rocky Mountain spotted fever (RMSF), caused by the etiological agent Rickettsia rickettsii, is the most severe and frequently reported rickettsial illness in the United States, and is commonly diagnosed throughout the southeast. With the discoveries of Rickettsia parkeri and other spotted fever group rickettsiae (SFGR) in ticks, it remains inconclusive if the cases reported as RMSF are truly caused by R. rickettsii or other SFGR. Arkansas reports one of the highest incidence rates of RMSF in the country; consequently, to identify the rickettsiae in Arkansas, 1,731 ticks, 250 white-tailed deer, and 189 canines were screened by polymerase chain reaction (PCR) for the rickettsial genes gltA, rompB, and ompA. None of the white-tailed deer were positive, while two of the canines (1.1%) and 502 (29.0%) of the ticks were PCR positive. Five different tick species were PCR positive: 244 (37%) Amblyomma americanum L., 130 (38%) Ixodes scapularis Say, 65 (39%) Amblyomma maculatum (Koch), 30 (9%) Rhipicephalus sanguineus Latreille, 7 (4%) Dermacentor variabilis Say, and 26 (44%) unidentified Amblyomma ticks. None of the sequenced products were homologous to R. rickettsii. The most common Rickettsia via rompB amplification was Rickettsia montanensis and nonpathogenic Candidatus Rickettsia amblyommii, whereas with ompA amplification the most common Rickettsia was Ca. R. amblyommii. Many tick specimens collected in northwest Arkansas were PCR positive and these were commonly A. americanum harboring Ca. R. amblyommii, a currently nonpathogenic Rickettsia. Data reported here indicate that pathogenic R. rickettsii was absent from these ticks and suggest by extension that other SFGR are likely the causative agents for Arkansas diagnosed RMSF cases. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Gamma-irradiated scrub typhus immunogens: analysis for residual replicating rickettsiae

International Nuclear Information System (INIS)

Eisenberg, G.H. Jr.; Osterman, J.V.; Stephenson, E.H.

1980-01-01

Scrub thyphus immunogens that received inadequate gamma radiation contained residual, viable rickettsiae. The presence of these organisms in the host was masked by the rapid immune response elicited by the large number of inactivated rickettsiae. Transfer of homogenized spleen cells from immunized mice to normal syngeneic recipients provided a sensitive technique for the detection of these viable, replicating organisms

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

International Nuclear Information System (INIS)

Carl, M.; Dasch, G.A.

1986-01-01

The authors recently described a subset of OKT8, OKT3-positive lymphocytes from typhus-group rickettsia immune individuals which were capable of lysing autologous PHA-blasts or Epstein-Barr virus transformed B cells (LCL) infected with typhus-group rickettsiae. In order to determine if killing by these effectors was HLA-restricted, they stimulated peripheral blood mononuclear cells (PBMC) from typhus-group rickettsia immune individuals in vitro with typhus-group rickettsia-derived antigen for one week and then measured lysis of autologous LCL or HLA-mismatched LCL in a 4-6 hour Cr 51 -release assay. There was significant lysis of both the autologous and the HLA-mismatched infected targets as compared to the corresponding uninfected targets. Since this suggested that the effectors were lymphokine activated killers (LAK) rather than cytotoxic T lymphocytes, they then tested this hypothesis by stimulating PBMC from both immune and non-immune individuals in vitro for one week with purified interleukin 2 and measuring lysis of infected, autologous LCL. PBMC thus treated, from both immune and non-immune individuals, were capable of significantly lysing autologous, infected LCL as compared to the non-infected control. They therefore conclude that targets infected with typhus-group rickettsiae are susceptible to lysis to LAK

First report of Rickettsia raoultii and Rickettsia helvetica in Dermacentor reticulatus ticks from the Czech Republic

Czech Academy of Sciences Publication Activity Database

Rudolf, I.; Venclíková, Kristýna; Blažejová, H.; Betášová, L.; Mendel, J.; Hubálek, Z.; Parola, P.

2016-01-01

Roč. 7, č. 6 (2016), s. 1222-1224 ISSN 1877-959X Institutional support: RVO:61389013 Keywords : Rickettsia spp. * Dermacentor spp. * DEBONEL Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.230, year: 2016

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

DEFF Research Database (Denmark)

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......, Neisseria meningitidis, Haemophilus influenzae, S suis) and O tsutsugamushi, Rickettsia typhi/Rickettsia spp, and Leptospira spp infections in blood or cerebrospinal fluid (CSF). We analysed and compared causes and clinical and CSF characteristics between patient groups. FINDINGS: 1051 (95%) of 1112...... patients who presented had CSF available for analysis, of whom 254 (24%) had a CNS infection attributable to a bacterial or fungal pathogen. 90 (35%) of these 254 infections were caused by O tsutsugamushi, R typhi/Rickettsia spp, or Leptospira spp. These pathogens were significantly more frequent than...

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

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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. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Transovarial Transmission of Rickettsia spp. and Organ-Specific Infection of the Whitefly Bemisia tabaci

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Brumin, Marina; Levy, Maggie

2012-01-01

The whitefly Bemisia tabaci is a cosmopolitan insect pest that harbors Portiera aleyrodidarum, the primary obligatory symbiotic bacterium, and several facultative secondary symbionts. Secondary symbionts in B. tabaci are generally associated with the bacteriome, ensuring their vertical transmission; however, Rickettsia is an exception and occupies most of the body cavity, except the bacteriome. The mode of Rickettsia transfer between generations and its subcellular localization in insect organs have not been investigated. Using electron and fluorescence microscopy, we show that Rickettsia infects the digestive, salivary, and reproductive organs of the insect; however, it was not observed in the bacteriome. Rickettsia invades the oocytes during early developmental stages and resides in follicular cells and cytoplasm; it is mostly excluded when the egg matures; however, some bacterial cells remain in the egg, ensuring their transfer to subsequent generations. Rickettsia was localized to testicles and the spermatheca, suggesting a horizontal transfer between males and females during mating. The bacterium was further observed at large amounts in midgut cells, concentrating in vacuole-like structures, and was located in the hemolymph, specifically at exceptionally large amounts around bacteriocytes and in fat bodies. Organs further infected by Rickettsia included the primary salivary glands and stylets, sites of possible secretion of the bacterium outside the whitefly body. The close association between Rickettsia and the B. tabaci digestive system might be important for digestive purposes. The vertical transmission of Rickettsia to subsequent generations occurs via the oocyte and not, like other secondary symbionts, the bacteriome. PMID:22660706

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

DEFF Research Database (Denmark)

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

2009-01-01

Rickettsia helvetica has previously been proposed as an aetiological agent in sarcoidosis. The purpose of the present study was to detect possible signs of Rickettsia infection in a Danish population of patients with sarcoidosis. Twenty-six patients with newly diagnosed sarcoidosis were...... interview. Evidence of rickettsial infection was assessed by an immunofluorescence assay testing for antibodies towards Rickettsia as well as specific real-time polymerase chain reaction (PCR) on lung biopsy specimens. We performed fluorescent in situ hybridization (FISH) on the biopsies to detect....... There was no 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....

Evidence of Rickettsia and Orientia Infections Among Abattoir Workers in Djibouti.

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Horton, Katherine C; Jiang, Ju; Maina, Alice; Dueger, Erica; Zayed, Alia; Ahmed, Ammar Abdo; Pimentel, Guillermo; Richards, Allen L

2016-08-03

Of 49 workers at a Djiboutian abattoir, eight (16%, 95% confidence interval [CI]: 9-29) were seropositive against spotted fever group rickettsiae (SFGR), two (4%, 95% CI: 1-14) against typhus group rickettsiae, and three (6%, 95% CI: 2-17) against orientiae. One worker (9%, 95% CI: 2-38) seroconverted against orientiae during the study period. This is the first evidence of orientiae exposure in the Horn of Africa. SFGR were also identified by polymerase chain reaction in 32 of 189 (11%, 95% CI: 8-15) tick pools from 26 of 72 (36%) cattle. Twenty-five (8%, 95% CI: 6-12) tick pools were positive for Rickettsia africae, the causative agent of African tick-bite fever. Health-care providers in Djibouti should be aware of the possibility of rickettsiae infections among patients, although further research is needed to determine the impact of these infections in the country. © The American Society of Tropical Medicine and Hygiene.

Detection of Rickettsia bellii and Rickettsia amblyommii in Amblyomma longirostre (Acari: Ixodidae) from Bahia state, Northeast Brazil.

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McIntosh, Douglas; Bezerra, Rodrigo Alves; Luz, Hermes Ribeiro; Faccini, João Luiz Horacio; Gaiotto, Fernanda Amato; Giné, Gastón Andrés Fernandez; Albuquerque, George Rego

2015-01-01

Studies investigating rickettsial infections in ticks parasitizing wild animals in the Northeast region of Brazil have been confined to the detection of Rickettsia amblyommii in immature stages of Amblyomma longirostre collected from birds in the state of Bahia, and in immatures and females of Amblyomma auricularium collected from the striped hog-nosed skunk (Conepatus semistriatus) and armadillos (Euphractus sexcinctus) in the state of Pernambuco. The current study extends the distribution of R. amblyommii (strain Aranha), which was detected in A. longirostre collected from the thin-spined porcupine Chaetomys subspinosus and the hairy dwarf porcupine Coendou insidiosus. In addition, we report the first detection of Rickettsia bellii in adults of A. longirostre collected from C. insidiosus in the state of Bahia.

Shell-vial culture and real-time PCR applied to Rickettsia typhi and Rickettsia felis detection.

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Segura, Ferran; Pons, Immaculada; Pla, Júlia; Nogueras, María-Mercedes

2015-11-01

Murine typhus is a zoonosis transmitted by fleas, whose etiological agent is Rickettsia typhi. Rickettsia felis infection can produces similar symptoms. Both are intracellular microorganisms. Therefore, their diagnosis is difficult and their infections can be misdiagnosed. Early diagnosis prevents severity and inappropriate treatment regimens. Serology can't be applied during the early stages of infection because it requires seroconversion. Shell-vial (SV) culture assay is a powerful tool to detect Rickettsia. The aim of the study was to optimize SV using a real-time PCR as monitoring method. Moreover, the study analyzes which antibiotics are useful to isolate these microorganisms from fleas avoiding contamination by other bacteria. For the first purpose, SVs were inoculated with each microorganism. They were incubated at different temperatures and monitored by real-time PCR and classical methods (Gimenez staining and indirect immunofluorescence assay). R. typhi grew at all temperatures. R. felis grew at 28 and 32 °C. Real-time PCR was more sensitive than classical methods and it detected microorganisms much earlier. Besides, the assay sensitivity was improved by increasing the number of SV. For the second purpose, microorganisms and fleas were incubated and monitored in different concentrations of antibiotics. Gentamicin, sufamethoxazole, trimethoprim were useful for R. typhi isolation. Gentamicin, streptomycin, penicillin, and amphotericin B were useful for R. felis isolation. Finally, the optimized conditions were used to isolate R. felis from fleas collected at a veterinary clinic. R. felis was isolated at 28 and 32 °C. However, successful establishment of cultures were not possible probably due to sub-optimal conditions of samples.

First report of Rickettsia raoultii and Rickettsia helvetica in Dermacentor reticulatus ticks from the Czech Republic

Czech Academy of Sciences Publication Activity Database

Rudolf, Ivo; Venclíková, Kristýna; Blažejová, Hana; Betášová, Lenka; Mendel, Jan; Hubálek, Zdeněk; Parola, P.

2016-01-01

Roč. 7, č. 6 (2016), s. 1222-1224 ISSN 1877-959X Institutional support: RVO:68081766 Keywords : Rickettsia spp. * Dermacentor spp. * DEBONEL * SENLAT Subject RIV: GJ - Animal Vermins ; Diseases , Veterinary Medicine Impact factor: 3.230, year: 2016

Rickettsia parkeri in Amblyomma dubitatum ticks in a spotted fever focus from the Brazilian Pampa.

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Weck, Bárbara; Dall'Agnol, Bruno; Souza, Ugo; Webster, Anelise; Stenzel, Bárbara; Klafke, Guilherme; Martins, João Ricardo; Reck, José

2017-07-01

Spotted fever is an acute febrile illness, which is considered severely underreported and misdiagnosed in the Brazilian Pampa, caused by tick-borne Rickettsiae. Here, we report an eco-epidemiological investigation of Rickettsia spp. in ticks from a spotted fever focus in Toropi, southern Brazil. Ticks were collected from capybara carcasses and processed individually to obtain genomic DNA. Rickettsia was investigated using PCR that amplified the rickettsial fragments of the gltA, ompA and htrA genes. DNA from Rickettsia parkeri was found in four of 14 Amblyomma dubitatum ticks collected from capybara carcasses in Toropi and the nearby municipality of Quevedos. We also tested 210A. dubitatum ticks obtained from road-killed capybaras of other localities from the Pampa biome; none of them were positive for Rickettsiae. Thus, in Rio Grande do Sul, two Rickettsia species can be potentially associated to spotted fever: Rickettsia sp. strain Atlantic Rainforest, associated with Amblyomma ovale ticks in the Atlantic Rainforest biome, and R. parkeri, associated both with Amblyomma tigrinum and A. dubitatum ticks in the Pampa biome. Our results reinforce that R. parkeri may be the agent associated with spotted fever in the Brazilian Pampa. Copyright © 2017 Elsevier B.V. All rights reserved.

Rickettsia conorii transcriptional response within inoculation eschar.

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Patricia Renesto

Full Text Available 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 gene expression from infected human skin biopsies. Our data showed that R. conorii exhibited a striking transcript signature that is remarkably conserved across patients, regardless of genotype. The expression profiles obtained using custom Agilent microarrays were validated by quantitative RT-PCR. Within eschars, the amount of detected R. conorii transcripts was of 55%, this value being of 74% for bacteria grown in Vero cells. In such infected host tissues, approximately 15% (n = 211 of the total predicted R. conorii ORFs appeared differentially expressed compared to bacteria grown in standard laboratory conditions. These genes are mostly down-regulated and encode proteins essential for bacterial replication. Some of the strategies displayed by rickettsiae to overcome the host defense barriers, thus avoiding killing, were also pointed out. The observed up-regulation of rickettsial genes associated with DNA repair is likely to correspond to a DNA-damaging agent enriched environment generated by the host cells to eradicate the pathogens. Survival of R. conorii within eschars also involves adaptation to osmotic stress, changes in cell surface proteins and up-regulation of some virulence factors. Interestingly, in contrast to down-regulated transcripts, we noticed that up-regulated ones rather exhibit a small nucleotide size, most of them being exclusive for the spotted fever group rickettsiae. CONCLUSION/SIGNIFICANCE: Because eschar is a site for rickettsial

Association of Borrelia and Rickettsia spp. and bacterial loads in Ixodes ricinus ticks.

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Raulf, Marie-Kristin; Jordan, Daniela; Fingerle, Volker; Strube, Christina

2018-01-01

In recent years, awareness of coinfections has increased as synergistic or antagonistic effects on interacting bacteria have been observed. To date, several reports on coinfections of ticks with Rickettsia and Borrelia spp. are available. However, associations are rarely described and studies are based on rather low sample sizes. In the present study, coinfections of Ixodes ricinus with these pathogens were investigated by determining their association in a meta-analysis. A total of 5079 tick samples examined for Rickettsia and Borrelia spp. via probe-based quantitative real-time PCR in previous prevalence studies or as submitted diagnostic material were included. In Borrelia-positive ticks, genospecies were determined by Reverse Line Blot. Determination of bacterial loads resulted in an increase between developmental tick stages with highest mean bacterial loads in female ticks (7.96×10 4 in Borrelia single-infected, 4.87×10 5 in Rickettsia single-infected and 3.22×10 5 in Borrelia-Rickettsia coinfected females). The determined Borrelia-Rickettsia tick coinfection rate was 12.3% (626/5079) with a significant difference to the expected coinfection rate of 9.0% (457/5079). A significant slight association as well as correlation between Borrelia and Rickettsia were determined. In addition, a significant interrelation of the bacterial load in coinfected ticks was shown. At the level of Borrelia genospecies, significant weak associations with Rickettsia spp. were detected for B. afzelii, B. garinii/bavariensis, B. valaisiana and B. lusitaniae. The positive association provides evidence for interactions between Borrelia and Rickettsia spp. in the tick vector, presumably resulting in higher bacterial replication rates in the tick vector and possibly the reservoir host. However, coinfection may impact the vector negatively as indicated by an absent increase in coinfection rates from nymphs to adults. Future studies are needed to investigate the underlying mechanisms of

Selfish DNA in protein-coding genes of Rickettsia.

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Ogata, H; Audic, S; Barbe, V; Artiguenave, F; Fournier, P E; Raoult, D; Claverie, J M

2000-10-13

Rickettsia conorii, the aetiological agent of Mediterranean spotted fever, is an intracellular bacterium transmitted by ticks. Preliminary analyses of the nearly complete genome sequence of R. conorii have revealed 44 occurrences of a previously undescribed palindromic repeat (150 base pairs long) throughout the genome. Unexpectedly, this repeat was found inserted in-frame within 19 different R. conorii open reading frames likely to encode functional proteins. We found the same repeat in proteins of other Rickettsia species. The finding of a mobile element inserted in many unrelated genes suggests the potential role of selfish DNA in the creation of new protein sequences.

Rickettsia amblyommatis sp. nov., a spotted fever group Rickettsia associated with multiple species of Amblyomma ticks in North, Central and South America.

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Karpathy, Sandor E; Slater, Kimetha S; Goldsmith, Cynthia S; Nicholson, William L; Paddock, Christopher D

2016-12-01

In 1973, investigators isolated a rickettsial organism, designated strain WB-8-2T, from an adult Amblyomma americanum tick collected at Land Between the Lakes National Recreation Area, TN, USA. This organism is now recognized as highly prevalent in A. americanum, as well as several other Amblyomma species found throughout the Western hemisphere. It has been suggested that cross-reactivity to WB-8-2T and similar strains contributes to the increasing number of spotted fever cases reported in the USA. In 1995, investigators provided preliminary evidence that this strain, as well as another strain from Missouri, represented a distinct taxonomic unit within the genus Rickettsia by evaluating sequences of the 16S rRNA and 17 kDa protein genes. However, the bacterium was never formally named, despite the use of the designation 'Rickettsia amblyommii' and later 'Candidatus Rickettsia amblyommii', for more than 20 years in the scientific literature. Herein, we provide additional molecular evidence to identify strain WB-8-2T as a representative strain of a unique rickettsial species and present a formal description for the species, with the proposed name modified to Rickettsia amblyommatis sp. nov. to conform to the International Code of Nomenclature of Prokaryotes. We also establish a pure culture of strain WB-8-2T and designate it as the type strain for the species. The type strain is WB-8-2T (=CRIRC RAM004T=CSURP2882T).

Extremely Low Genomic Diversity of Rickettsia japonica Distributed in Japan.

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Akter, Arzuba; Ooka, Tadasuke; Gotoh, Yasuhiro; Yamamoto, Seigo; Fujita, Hiromi; Terasoma, Fumio; Kida, Kouji; Taira, Masakatsu; Nakadouzono, Fumiko; Gokuden, Mutsuyo; Hirano, Manabu; Miyashiro, Mamoru; Inari, Kouichi; Shimazu, Yukie; Tabara, Kenji; Toyoda, Atsushi; Yoshimura, Dai; Itoh, Takehiko; Kitano, Tomokazu; Sato, Mitsuhiko P; Katsura, Keisuke; Mondal, Shakhinur Islam; Ogura, Yoshitoshi; Ando, Shuji; Hayashi, Tetsuya

2017-01-01

Rickettsiae are obligate intracellular bacteria that have small genomes as a result of reductive evolution. Many Rickettsia species of the spotted fever group (SFG) cause tick-borne diseases known as "spotted fevers". The life cycle of SFG rickettsiae is closely associated with that of the tick, which is generally thought to act as a bacterial vector and reservoir that maintains the bacterium through transstadial and transovarial transmission. Each SFG member is thought to have adapted to a specific tick species, thus restricting the bacterial distribution to a relatively limited geographic region. These unique features of SFG rickettsiae allow investigation of how the genomes of such biologically and ecologically specialized bacteria evolve after genome reduction and the types of population structures that are generated. Here, we performed a nationwide, high-resolution phylogenetic analysis of Rickettsia japonica, an etiological agent of Japanese spotted fever that is distributed in Japan and Korea. The comparison of complete or nearly complete sequences obtained from 31 R. japonica strains isolated from various sources in Japan over the past 30 years demonstrated an extremely low level of genomic diversity. In particular, only 34 single nucleotide polymorphisms were identified among the 27 strains of the major lineage containing all clinical isolates and tick isolates from the three tick species. Our data provide novel insights into the biology and genome evolution of R. japonica, including the possibilities of recent clonal expansion and a long generation time in nature due to the long dormant phase associated with tick life cycles. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Pathogenic potential of a Costa Rican strain of 'Candidatus Rickettsia amblyommii' in guinea pigs (Cavia porcellus) and protective immunity against Rickettsia rickettsii.

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Rivas, Juan J; Moreira-Soto, Andrés; Alvarado, Gilberth; Taylor, Lizeth; Calderón-Arguedas, Olger; Hun, Laya; Corrales-Aguilar, Eugenia; Morales, Juan Alberto; Troyo, Adriana

2015-09-01

'Candidatus Rickettsia amblyommii' is a spotted fever group rickettsia that is not considered pathogenic, although there is serologic evidence of possible infection in animals and humans. The aim of this study was to evaluate the pathogenic potential of a Costa Rican strain of 'Candidatus R. amblyommii' in guinea pigs and determine its capacity to generate protective immunity against a subsequent infection with a local strain of Rickettsia rickettsii isolated from a human case. Six guinea pigs were inoculated with 'Candidatus R. amblyommii' strain 9-CC-3-1 and two controls with cell culture medium. Health status was evaluated, and necropsies were executed at days 2, 4, and 13. Blood and tissues were processed by PCR to detect the gltA gene, and end titers of anti-'Candidatus R. amblyommii' IgG were determined by indirect immunofluorescence. To evaluate protective immunity, another 5 guinea pigs were infected with 'Candidatus R. amblyommii' (IGPs). After 4 weeks, these 5 IGPs and 3 controls (CGPs) were inoculated with pathogenic R. rickettsii. Clinical signs and titers of anti-Rickettsia IgG were determined. IgG titers reached 1:512 at day 13 post-infection with 'Candidatus R. amblyommii'. On day 2 after inoculation, two guinea pigs had enlarged testicles and 'Candidatus R. amblyommii' DNA was detected in testicles. Histopathology confirmed piogranulomatous orchitis with perivascular inflammatory infiltrate in the epididymis. In the protective immunity assay, anti-Rickettsia IgG end titers after R. rickettsii infection were lower in IGPs than in CGPs. IGPs exhibited only transient fever, while CGP showed signs of severe disease and mortality. R. rickettsii was detected in testicles and blood of CGPs. Results show that the strain 9-CC-3-1 of 'Candidatus R. amblyommii' was able to generate pathology and an antibody response in guinea pigs. Moreover, its capacity to generate protective immunity against R. rickettsii may modulate the epidemiology and severity of Rocky

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

International Nuclear Information System (INIS)

Demkin, V.V.; Rydkina, E.B.; Likhoded, L.Ya.; Ignatovich, V.F.; Genig, V.A.; Balayeva, N.M.

1994-01-01

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)

Prevalence and diversity of human pathogenic rickettsiae in urban versus rural habitats, Hungary.

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Szekeres, Sándor; Docters van Leeuwen, Arieke; Rigó, Krisztina; Jablonszky, Mónika; Majoros, Gábor; Sprong, Hein; Földvári, Gábor

2016-02-01

Tick-borne rickettsioses belong to the important emerging infectious diseases worldwide. We investigated the potential human exposure to rickettsiae by determining their presence in questing ticks collected in an urban park of Budapest and a popular hunting and recreational forest area in southern Hungary. Differences were found in the infectious risk between the two habitats. Rickettsia monacensis and Rickettsia helvetica were identified with sequencing in questing Ixodes ricinus, the only ticks species collected in the city park. Female I. ricinus had a particularly high prevalence of R. helvetica (45%). Tick community was more diverse in the rural habitat with Dermacentor reticulatus ticks having especially high percentage (58%) of Rickettsia raoultii infection. We conclude that despite the distinct eco-epidemiological traits, the risk (hazard and exposure) of acquiring human pathogenic rickettsial infections in both the urban and the rural study sites exists.

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Francisella-Like Endosymbionts and Rickettsia Species in Local and Imported Hyalomma Ticks.

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Azagi, Tal; Klement, Eyal; Perlman, Gidon; Lustig, Yaniv; Mumcuoglu, Kosta Y; Apanaskevich, Dmitry A; Gottlieb, Yuval

2017-09-15

Hyalomma ticks (Acari: Ixodidae) are hosts for Francisella -like endosymbionts (FLE) and may serve as vectors of zoonotic disease agents. This study aimed to provide an initial characterization of the interaction between Hyalomma and FLE and to determine the prevalence of pathogenic Rickettsia in these ticks. Hyalomma marginatum , Hyalomma rufipes , Hyalomma dromedarii , Hyalomma aegyptium , and Hyalomma excavatum ticks, identified morphologically and molecularly, were collected from different hosts and locations representing the distribution of the genus Hyalomma in Israel, as well as from migratory birds. A high prevalence of FLE was found in all Hyalomma species (90.6%), as well as efficient maternal transmission of FLE (91.8%), and the localization of FLE in Malpighian tubules, ovaries, and salivary glands in H. marginatum Furthermore, we demonstrated strong cophylogeny between FLE and their host species. Contrary to FLE, the prevalence of Rickettsia ranged from 2.4% to 81.3% and was significantly different between Hyalomma species, with a higher prevalence in ticks collected from migratory birds. Using ompA gene sequences, most of the Rickettsia spp. were similar to Rickettsia aeschlimannii , while a few were similar to Rickettsia africae of the spotted fever group (SFG). Given their zoonotic importance, 249 ticks were tested for Crimean Congo hemorrhagic fever virus infection, and all were negative. The results imply that Hyalomma and FLE have obligatory symbiotic interactions, indicating a potential SFG Rickettsia zoonosis risk. A further understanding of the possible influence of FLE on Hyalomma development, as well as on its infection with Rickettsia pathogens, may lead to novel ways to control tick-borne zoonoses. IMPORTANCE This study shows that Francisella -like endosymbionts were ubiquitous in Hyalomma , were maternally transmitted, and cospeciated with their hosts. These findings imply that the interaction between FLE and Hyalomma is of an obligatory

Molecular detection of Rickettsia, Anaplasma, Coxiella and Francisella bacteria in ticks collected from Artiodactyla in Thailand.

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Sumrandee, Chalao; Baimai, Visut; Trinachartvanit, Wachareeporn; Ahantarig, Arunee

2016-07-01

A total of 79 ticks collected from Sambar deer (Cervus unicolor), Barking deer (Muntiacus muntjak) and Wild boar (Sus scrofa) were examined by PCR for the presence of Rickettsia, Anaplasma, Coxiella, and Francisella bacteria. Of the 79 ticks, 13% tested positive for Rickettsia, 15% tested positive for Anaplasma, 4% tested positive for Coxiella, and 3% tested positive for Francisella. Interestingly, triple infection with Anaplasma, Rickettsia and Francisella was determined in a Dermacentor auratus tick. Moreover, another triple infection with Rickettsia, Anaplasma, and Coxiella was found in a Haemaphysalis lagrangei tick. Double infection of Rickettsia with Coxiella was also detected in another H. lagrangei tick. From the phylogenetic analyses, we found a Rickettsia sp. with a close evolutionary relationship to Rickettsia bellii in the H. lagrangei tick. We also found the first evidence of a Rickettsia sp. that is closely related to Rickettsia tamurae in Rhipicephalus (Boophilus) microplus ticks from Thailand. H. lagrangei and Haemaphysalis obesa ticks collected from Sambar deer tested positive for Anaplasma species form the same clade with Anaplasma bovis. In contrast, other H. lagrangei ticks collected from Sambar deer and D. auratus ticks collected from Wild boar were also reported for the first time to be infected with an Anaplasma species that is closely related to Anaplasma platys. The phylogenetic analysis of the 16S rRNA gene of Coxiella bacteria revealed that Coxiella symbionts from H. lagrangei formed a distinctly different lineage from Coxiella burnetii (a human pathogen). Additionally, Francisella bacteria identified in D. auratus ticks were found to be distantly related to a group of pathogenic Francisella species. The identification of these bacteria in several feeding ticks suggests the risk of various emerging tick-borne diseases and endosymbionts in humans, wildlife, and domestic animals in Thailand. Copyright © 2016 Elsevier GmbH. All rights

Diagnostic Assay for Rickettsia japonica

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Hanaoka, Nozomu; Matsutani, Minenosuke; Kawabata, Hiroki; Yamamoto, Seigo; Fujita, Hiromi; Sakata, Akiko; Azuma, Yoshinao; Ogawa, Motohiko; Takano, Ai; Watanabe, Haruo; Kishimoto, Toshio; Shirai, Mutsunori; Kurane, Ichiro

2009-01-01

We developed a specific and rapid detection system for Rickettsia japonica and R. heilongjiangensis, the causative agents of spotted fever, using a TaqMan minor groove binder probe for a particular open reading frame (ORF) identified by the R. japonica genome project. The target ORF was present only in R. japonica–related strains. PMID:19961684

Antibodies to Rickettsia spp. and Borrelia burgdorferi in Spanish Wild Red Foxes (Vulpes vulpes).

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Lledó, Lourdes; Serrano, José Luis; Isabel Gegúndez, María; Giménez-Pardo, Consuelo; Saz, José Vicente

2016-01-01

We examined 314 red foxes (Vulpes vulpes) from the province of Soria, Spain, for Rickettsia typhi, Rickettsia slovaca, and Borrelia burgdorferi infection. Immunofluorescence assays showed 1.9% had antibodies to R. typhi, 6.7% had antibodies to R. slovaca, and 8.3% had antibodies to B. burgdorferi. Serostatus was not correlated with sex or age. Because red foxes can be infected by Rickettsiae and B. burgdorferi, presence of red foxes may be and indicator for the presence of these pathogens.

New records of tick-associated spotted fever group Rickettsia in an Amazon-Savannah ecotone, Brazil.

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Aguirre, A A R; Garcia, Marcos Valério; Costa, Ivaneide Nunes da; Csordas, Bárbara Guimarães; Rodrigues, Vinícius da Silva; Medeiros, Jansen Fernandes; Andreotti, Renato

2018-05-01

Human rickettsiosis has been recorded in the Amazon Biome. However, the epidemiological cycle of causative rickettsiae has not been fully accounted for in the Amazon region. This study investigates the presence of spotted fever group (SFG) Rickettsia spp. in free-living unfed ticks of the Amblyomma genus. The study was conducted in seven municipalities in Rondonia State, Brazil, where the main biomes are Amazon forest, Brazilian Savannah and their ecotones (areas of ecological tension between open ombrophilous forest and savannah). The following tick species were collected: Amblyomma cajennense (sensu lato) s.l., A. cajennense (sensu stricto) s.s., A. coelebs, A. naponense, A. oblongoguttatum, A. romitii, A. scalpturatum and A. sculptum. A total of 167 adults, 248 nymphs and 1004 larvae were subjected to DNA extraction and polymerase chain reaction (PCR) to determine the presence of SFG Rickettsia spp. PCR-positive samples included: one A. cajennense s.s. female and one A. cajennense s.l. male from a rural area in Vilhena Municipality; 10 nymphs and a sample of larvae of A. cajennense s.l. from a peri-urban area in Cacoal Municipality; and an A. oblongoguttatum adult male from a rural area of Pimenta Bueno Municipality. All sequences obtained exhibited 100% identity with Rickettsia amblyommatis sequences. This is the first confirmation of SFG Rickettsia in an A. oblongoguttatum tick. Furthermore, this is the first record of SFG Rickettsia in the municipalities targeted by this study. These results warn that SFG Rickettsia circulation poses a threat in Rondonia State (among Amazon-Savannah ecotones), and that this threat is increased by the fact that SFG Rickettsia infect a human-biting tick species hitherto unconfirmed as a vector. Copyright © 2018 Elsevier GmbH. All rights reserved.

The Facultative Symbiont Rickettsia Protects an Invasive Whitefly against Entomopathogenic Pseudomonas syringae Strains.

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Hendry, Tory A; Hunter, Martha S; Baltrus, David A

2014-12-01

Facultative endosymbionts can benefit insect hosts in a variety of ways, including context-dependent roles, such as providing defense against pathogens. The role of some symbionts in defense may be overlooked, however, when pathogen infection is transient, sporadic, or asymptomatic. The facultative endosymbiont Rickettsia increases the fitness of the sweet potato whitefly (Bemisia tabaci) in some populations through mechanisms that are not yet understood. In this study, we investigated the role of Rickettsia in mediating the interaction between the sweet potato whitefly and Pseudomonas syringae, a common environmental bacterium, some strains of which are pathogenic to aphids. Our results show that P. syringae multiplies within whiteflies, leading to host death, and that whiteflies infected with Rickettsia show a decreased rate of death due to P. syringae. Experiments using plants coated with P. syringae confirmed that whiteflies can acquire the bacteria at a low rate while feeding, leading to increased mortality, particularly when the whiteflies are not infected with Rickettsia. These results suggest that P. syringae may affect whitefly populations in nature and that Rickettsia can ameliorate this effect. This study highlights the possible importance of interactions among opportunistic environmental pathogens and endosymbionts of insects. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Bacteria of the genera Ehrlichia and Rickettsia in ticks of the family Ixodidae with medical importance in Argentina.

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Sebastian, Patrick S; Tarragona, Evelina L; Bottero, María N Saracho; Mangold, Atilio J; Mackenstedt, Ute; Nava, Santiago

2017-01-01

The aim of this study was to get an overview about the occurrence of bacteria from the genus Ehrlichia and Rickettsia in ixodid ticks with medical importance in Argentina. Therefore, in 2013 and 2014, free-living ticks were collected in different provinces of northern Argentina. These ticks were determined as Amblyomma sculptum, Amblyomma neumanni, Amblyomma parvum, Amblyomma triste, Amblyomma ovale, Amblyomma tonelliae and Haemaphysalis juxtakochi. All samples were tested to determine the infection with Ehrlichia spp. and Rickettsia spp. by PCR assays. Rickettsial DNA was detected in all tested tick species, with the exception of A. tonelliae. 'Candidatus Rickettsia amblyommii', 'Candidatus Rickettsia andeanae', and Rickettsia parkeri were found in A. neumanni, A. parvum, and A. triste, respectively. Another rickettsial species, Rickettsia bellii, was found in A. sculptum, A. ovale and H. juxtakochi. None of the tested ticks showed infection with Ehrlichia. The results of the study demonstrate that Rickettsia species belonging to the spotted fever group are associated with various species of Amblyomma throughout a wide area of northern Argentina, where cases of Amblyomma ticks biting humans are common.

A novel spotted fever group Rickettsia infecting Amblyomma parvitarsum (Acari: Ixodidae) in highlands of Argentina and Chile.

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Ogrzewalska, Maria; Nieri-Bastos, Fernanda A; Marcili, Arlei; Nava, Santiago; González-Acuña, Daniel; Muñoz-Leal, Sebastián; Ruiz-Arrondo, Ignacio; Venzal, José M; Mangold, Atilio; Labruna, Marcelo B

2016-04-01

The tick Amblyomma parvitarsum (Acari: Ixodidae) has established populations in Andean and Patagonic environments of South America. For the present study, adults of A. parvitarsum were collected in highland areas (elevation >3500 m) of Argentina and Chile during 2009-2013, and tested by PCR for rickettsial infection in the laboratory, and isolation of rickettsiae in Vero cell culture by the shell vial technique. Overall, 51 (62.2%) out of 82 A. parvitarsum adult ticks were infected by spotted fever group (SFG) rickettsiae, which generated DNA sequences 100% identical to each other, and when submitted to BLAST analysis, they were 99.3% identical to corresponding sequence of the ompA gene of Rickettsia sp. strain Atlantic rainforest. Rickettsiae were successfully isolated in Vero cell culture from two ticks, one from Argentina and one from Chile. DNA extracted from the third passage of the isolates of Argentina and Chile were processed by PCR, resulting in partial sequences for three rickettsial genes (gltA, ompB, ompA). These sequences were concatenated and aligned with rickettsial corresponding sequences available in GenBank. Phylogenetic analysis revealed that the A. pavitarsum rickettsial agent grouped under high bootstrap support in a clade composed by the SFG pathogens R. sibirica, R. africae, R. parkeri, Rickettsia sp. strain Atlantic rainforest, and two unnamed SFG agents of unknown pathogenicty, Rickettsia sp. strain NOD, and Rickettsia sp. strain ApPR. The pathogenic role of this A. parvitarsum rickettsia cannot be discarded, since several species of tick-borne rickettsiae that were considered nonpathogenic for decades are now associated with human infections. Copyright © 2016. Published by Elsevier GmbH.

Detecção de proteínas imunorreativas de Rickettsia sp. cepa Mata Atlântica

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Caroline S. Oliveira

Full Text Available RESUMO: A Febre Maculosa Brasileira (FMB é uma doença infecciosa, transmitida por carrapatos ao homem. Uma nova riquetsiose humana foi descrita como causadora de Febre Maculosa no Estado de São Paulo, sendo denominada de Rickettsia sp. cepa Mata Atlântica. O presente trabalho teve como objetivo detectar e identificar proteínas com potencial de estimular o sistema imune de hospedeiro mamífero, desta nova cepa descrita. Para tanto, foi realizado a extração proteica total de Rickettsia sp. cepa Mata Atlântica. As proteínas extraídas foram fracionadas por eletroforese. As bandas proteicas foram transferidas para membranas de nitrocelulose por migração elétrica e submetidas à técnica de Western-blot, para detecção proteica. Ao todo sete proteínas imunorreativas foram detectadas. Duas proteínas apresentaram maior abundancia, com peso molecular, de 200 e 130 kDa respectivamente. Através da comparação de mapas proteômicos existentes e pelo peso molecular que estas proteínas apresentaram, sugere-se que as duas proteínas detectadas representem rOmpA (200 kDa e rOmpB (130 kDa. As demais proteínas detectadas apresentaram menor ocorrência e peso molecular inferior a 78 kDa, podendo representar membros da família de antígenos de superfície celular (Sca - Surface cell antigen. As proteínas detectadas poderão servir como base de estudo na elaboração de métodos diagnósticos sensíveis e específicos, no desenvolvimento de vacinas, além de possibilitarem novos estudos para terapias mais eficazes.

Identificación y caracterización de la población total de las células ganglionares de la retina en rata : nuevos métodos de trazado, expresión de melanopsina y de factores de transcripción Brn3:estudio de la respuesta neuronal y microglial a la axotomía y efecto del envejecimiento en la retina

OpenAIRE

Nadal Nicolás, Francisco Manuel

2015-01-01

Introducción La retina es parte del sistema nervioso central (SNC) y se localiza en la cara interna del globo ocular. Su función principal es la fototransducción de las ondas electromagnéticas del espectro de la luz visible en energía eléctrica. Esta función es realizada por los fotorreceptores (conos y bastones). Tras su procesamiento, la información llega a las células ganglionares de retina (CGR). Las CGR son las únicas neuronas aferentes de la retina y transmiten la información visual ...

The Detection of Spotted Fever Group Rickettsia DNA in Tick Samples From Pastoral Communities in Kenya.

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Koka, Hellen; Sang, Rosemary; Kutima, Helen Lydia; Musila, Lillian

2017-05-01

In this study, ticks from pastoral communities in Kenya were tested for Rickettsia spp. infections in geographical regions where the presence of tick-borne arboviruses had previously been reported. Rickettsial and arbovirus infections have similar clinical features which makes differential diagnosis challenging when both diseases occur. The tick samples were tested for Rickettsia spp. by conventional PCR using three primer sets targeting the gltA, ompA, and ompB genes followed by amplicon sequencing. Of the tick pools screened, 25% (95/380) were positive for Rickettsia spp. DNA using the gltA primer set. Of the tick-positive pools, 60% were ticks collected from camels. Rickettsia aeschlimannii and R. africae were the main Rickettsia spp. detected in the tick pools sequenced. The findings of this study indicate that multiple Rickettsia species are circulating in ticks from pastoral communities in Kenya and could contribute to the etiology of febrile illness in these areas. Diagnosis and treatment of rickettsial infections should be a public health priority in these regions. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Molecular Detection and Identification of Spotted Fever Group Rickettsiae in Ticks Collected from the West Bank, Palestinian Territories.

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Suheir Ereqat

2016-01-01

Full Text Available Tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group (SFG rickettsiae. Although Spotted Fever is prevalent in the Middle East, no reports for the presence of tick-borne pathogens are available or any studies on the epidemiology of this disease in the West Bank. We aimed to identify the circulating hard tick vectors and genetically characterize SFG Rickettsia species in ixodid ticks from the West Bank-Palestinian territories.A total of 1,123 ixodid ticks belonging to eight species (Haemaphysalis parva, Haemaphysalis adleri, Rhipicephalus turanicus, Rhipicephalus sanguineus, Rhipicephalus bursa, Hyalomma dromedarii, Hyalomma aegyptium and Hyalomma impeltatum were collected from goats, sheep, camels, dogs, a wolf, a horse and a tortoise in different localities throughout the West Bank during the period of January-April, 2014. A total of 867 ticks were screened for the presence of rickettsiae by PCR targeting a partial sequence of the ompA gene followed by sequence analysis. Two additional genes, 17 kDa and 16SrRNA were also targeted for further characterization of the detected Rickettsia species. Rickettsial DNA was detected in 148 out of the 867 (17% tested ticks. The infection rates in Rh. turanicus, Rh. sanguineus, H. adleri, H. parva, H. dromedarii, and H. impeltatum ticks were 41.7, 11.6, 16.7, 16.2, 11.8 and 20%, respectively. None of the ticks, belonging to the species Rh. bursa and H. aegyptium, were infected. Four SFG rickettsiae were identified: Rickettsia massiliae, Rickettsia africae, Candidatus Rickettsia barbariae and Candidatus Rickettsia goldwasserii.The results of this study demonstrate the geographic distribution of SFG rickettsiae and clearly indicate the presence of at least four of them in collected ticks. Palestinian clinicians should be aware of emerging tick-borne diseases in the West Bank, particularly infections due to R. massiliae and R. africae.

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

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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 Rickettsia-infected ticks. Methods Ticks were collected from a total of 14,789 birds during their seasonal migration northwards in spring 2009 and 2010 at bird observatories on two Mediterranean islands: Capri and Antikythira. All ticks were subjected to RNA extraction followed by cDNA synthesis and individually assayed with a real-time PCR targeting the citrate synthase (gltA) gene. For species identification of Rickettsia, multiple genes were sequenced. Results Three hundred and ninety-eight (2.7%) of all captured birds were tick-infested; some birds carried more than one tick. A total number of 734 ticks were analysed of which 353 ± 1 (48%) were Rickettsia-positive; 96% were infected with Rickettsia aeschlimannii and 4% with Rickettsia africae or unidentified Rickettsia species. The predominant tick taxon, Hyalomma marginatum sensu lato constituted 90% (n = 658) of the ticks collected. The remaining ticks were Ixodes frontalis, Amblyomma sp., Haemaphysalis sp., Rhipicephalus sp. and unidentified ixodids. Most ticks were nymphs (66%) followed by larvae (27%) and adult female ticks (0.5%). The majority (65%) of ticks was engorged and nearly all ticks contained visible blood. Conclusions Migratory birds appear to have a great impact on the dissemination of Rickettsia-infected ticks, some of which may originate from distant locations. The potential ecological, medical and veterinary implications of such Rickettsia infections need further examination. PMID:25011617

Molecular characterization of novel mosquito-borne Rickettsia spp. from mosquitoes collected at the Demilitarized Zone of the Republic of Korea.

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Maina, Alice N; Klein, Terry A; Kim, Heung-Chul; Chong, Sung-Tae; Yang, Yu; Mullins, Kristin; Jiang, Ju; St John, Heidi; Jarman, Richard G; Hang, Jun; Richards, Allen L

2017-01-01

Rickettsiae are associated with a diverse range of invertebrate hosts. Of these, mosquitoes could emerge as one of the most important vectors because of their ability to transmit significant numbers of pathogens and parasites throughout the world. Recent studies have implicated Anopheles gambiae as a potential vector of Rickettsia felis. Herein we report that a metagenome sequencing study identified rickettsial sequence reads in culicine mosquitoes from the Republic of Korea. The detected rickettsiae were characterized by a genus-specific quantitative real-time PCR assay and sequencing of rrs, gltA, 17kDa, ompB, and sca4 genes. Three novel rickettsial genotypes were detected (Rickettsia sp. A12.2646, Rickettsia sp. A12.2638 and Rickettsia sp. A12.3271), from Mansonia uniformis, Culex pipiens, and Aedes esoensis, respectively. The results underscore the need to determine the Rickettsia species diversity associated with mosquitoes, their evolution, distribution and pathogenic potential.

Detection of Rickettsia spp in Ticks by MALDI-TOF MS

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Yssouf, Amina; Almeras, Lionel; Terras, Jérôme; Socolovschi, Cristina; Raoult, Didier; Parola, Philippe

2015-01-01

Background Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has been shown to be an effective tool for the rapid identification of arthropods, including tick vectors of human diseases. Methodology/Principal Findings The objective of the present study was to evaluate the use of MALDI-TOF MS to identify tick species, and to determine the presence of rickettsia pathogens in the infected Ticks. Rhipicephalus sanguineus and Dermacentor marginatus Ticks infected or not by R. conorii conorii or R. slovaca, respectively, were used as experimental models. The MS profiles generated from protein extracts prepared from tick legs exhibited mass peaks that distinguished the infected and uninfected Ticks, and successfully discriminated the Rickettsia spp. A blind test was performed using Ticks that were laboratory-reared, collected in the field or removed from patients and infected or not by Rickettsia spp. A query against our in-lab arthropod MS reference database revealed that the species and infection status of all Ticks were correctly identified at the species and infection status levels. Conclusions/Significance Taken together, the present work demonstrates the utility of MALDI-TOF MS for a dual identification of tick species and intracellular bacteria. Therefore, MALDI-TOF MS is a relevant tool for the accurate detection of Rickettsia spp in Ticks for both field monitoring and entomological diagnosis. The present work offers new perspectives for the monitoring of other vector borne diseases that present public health concerns. PMID:25659152

Survey for hantaviruses, tick-borne encephalitis virus, and Rickettsia spp. in small rodents in Croatia.

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Svoboda, Petra; Dobler, Gerhard; Markotić, Alemka; Kurolt, Ivan-Christian; Speck, Stephanie; Habuš, Josipa; Vucelja, Marko; Krajinović, Lidija Cvetko; Tadin, Ante; Margaletić, Josip; Essbauer, Sandra

2014-07-01

In Croatia, several rodent- and vector-borne agents are endemic and of medical importance. In this study, we investigated hantaviruses and, for the first time, tick-borne encephalitis virus (TBEV) and Rickettsia spp. in small wild rodents from two different sites (mountainous and lowland region) in Croatia. In total, 194 transudate and tissue samples from 170 rodents (A. flavicollis, n=115; A. agrarius, n=2; Myodes glareolus, n=53) were tested for antibodies by indirect immunofluorescence assays (IIFT) and for nucleic acids by conventional (hantaviruses) and real-time RT-/PCRs (TBEV and Rickettsia spp.). A total of 25.5% (24/94) of the rodents from the mountainous area revealed specific antibodies against hantaviruses. In all, 21.3% (20/94) of the samples from the mountainous area and 29.0% (9/31) from the lowland area yielded positive results for either Puumala virus (PUUV) or Dobrava-Belgrade virus (DOBV) using a conventional RT-PCR. All processed samples (n=194) were negative for TBEV by IIFT or real-time RT-PCR. Serological evidence of rickettsial infection was detected in 4.3% (4/94) rodents from the mountainous region. Another 3.2% (3/94) rodents were positive for Rickettsia spp. by real-time PCR. None of the rodents (n=76) from the lowland area were positive for Rickettsia spp. by real-time PCR. Dual infection of PUUV and Rickettsia spp. was found in one M. glareolus from the mountainous area by RT-PCR and real-time PCR, respectively. To our knowledge, this is the first detection of Rickettsia spp. in small rodents from Croatia. Phylogenetic analyses of S- and M-segment sequences obtained from the two study sites revealed well-supported subgroups in Croatian PUUV and DOBV. Although somewhat limited, our data showed occurrence and prevalence of PUUV, DOBV, and rickettsiae in Croatia. Further studies are warranted to confirm these data and to determine the Rickettsia species present in rodents in these areas.

Investigation of Rickettsia, Coxiella burnetii and Bartonella in ticks from animals in South Africa.

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Halajian, Ali; Palomar, Ana M; Portillo, Aránzazu; Heyne, Heloise; Luus-Powell, Wilmien J; Oteo, José A

2016-03-01

Ticks are involved in the epidemiology of several human pathogens including spotted fever group (SFG) Rickettsia spp., Coxiella burnetii and Bartonella spp. Human diseases caused by these microorganisms have been reported from South Africa. The presence of SFG Rickettsia spp., C. burnetii and Bartonella spp. was investigated in 205 ticks collected from domestic and wild animals from Western Cape and Limpopo provinces (South Africa). Rickettsia massiliae was detected in 10 Amblyomma sylvaticum and 1 Rhipicephalus simus whereas Rickettsia africae was amplified in 7 Amblyomma hebraeum. Neither C. burnetii nor Bartonella spp. was found in the examined ticks. This study demonstrates the presence of the tick borne pathogen R. massiliae in South Africa (Western Cape and Limpopo provinces), and corroborates the presence of the African tick-bite fever agent (R. africae) in this country (Limpopo province). Copyright © 2015 Elsevier GmbH. All rights reserved.

Infection of Amblyomma ovale with Rickettsia species Atlantic rainforest in Serra do Mar, São Paulo State, Brazil.

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Luz, Hermes Ribeiro; McIntosh, Douglas; Furusawa, Guilherme P; Flausino, Walter; Rozental, Tatiana; Lemos, Elba R S; Landulfo, Gabriel A; Faccini, João Luiz H

2016-10-01

Rickettsia rickettsii and Rickettsia sp. strain Atlantic rainforest, that is considered to represent a genetic variant of Rickettsia parkeri, are confirmed as being capable of infecting humans in Brazil. This study reports the detection and characterization, by PCR and nucleotide sequencing, of Rickettsia sp. strain Atlantic rain forest in Amblyomma ovale parasitizing a human, in ticks infesting dogs and in free-living ticks collected from the environment where the human infestation was recorded. The data contribute to our knowledge of infection rates in A. ovale with Rickettsia sp. strain Atlantic rainforest and identified an additional location in the state of São Paulo populated with ticks infected with this emerging pathogen. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

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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.

Molecular detection of Rickettsia species in ticks collected from the southwestern provinces of the Republic of Korea.

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Noh, Yoontae; Lee, Yeong Seon; Kim, Heung-Chul; Chong, Sung-Tae; Klein, Terry A; Jiang, Ju; Richards, Allen L; Lee, Hae Kyeong; Kim, Su Yeon

2017-01-10

Rickettsiae constitute a group of arthropod-borne, Gram-negative, obligate intracellular bacteria that are the causative agents of diseases ranging from mild to life threatening that impact on medical and veterinary health worldwide. A total of 6,484 ticks were collected by tick drag from June-October 2013 in the southwestern provinces of the Republic of Korea (ROK) (Jeollanam, n = 3,995; Jeollabuk, n = 680; Chungcheongnam, n = 1,478; and Chungcheongbuk, n = 331). Ticks were sorted into 311 pools according to species, collection site, and stage of development. DNA preparations of tick pools were assayed for rickettsiae by 17 kDa antigen gene and ompA nested PCR (nPCR) assays and the resulting amplicons sequenced to determine the identity and prevalence of spotted fever group rickettsiae (SFGR). Haemaphysalis longicornis (4,471; 52 adults, 123 nymphs and 4,296 larvae) were the most commonly collected ticks, followed by Haemaphysalis flava (1,582; 28 adults, 263 nymphs and 1,291 larvae), and Ixodes nipponensis (431; 25 adults, 5 nymphs and 401 larvae). The minimum field infection rate/100 ticks (assuming 1 positive tick/pool) was 0.93% for the 17 kDa antigen gene and 0.82% for the ompA nPCR assays. The partial 17 kDa antigen and ompA gene sequences from positive pools of H. longicornis were similar to: Rickettsia sp. HI550 (99.4-100%), Rickettsia sp. FUJ98 (99.3-100%), Rickettsia sp. HIR/D91 (99.3-100%), and R. japonica (99.7%). One sequence of the partial 17 kDa antigen gene for H. flava was similar to Rickettsia sp. 17kd-005 (99.7%), while seven sequences of the 17 kDa antigen gene obtained from I. nipponensis ticks were similar to R. monacensis IrR/Munich (98.7-100%) and Rickettsia sp. IRS3 (98.9%). SFG rickettsiae were detected in three species of ixodid ticks collected in the southwestern provinces of the ROK during 2013. A number of rickettsiae have been recently reported from ticks in Korea, some of which were identified as medically

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

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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.

Bartonella quintana and Typhus Group Rickettsiae Exposure among Homeless Persons, Bogotá, Colombia.

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Faccini-Martínez, Álvaro A; Márquez, Andrea C; Bravo-Estupiñan, Diana M; Calixto, Omar-Javier; López-Castillo, Christian A; Botero-García, Carlos A; Hidalgo, Marylin; Cuervo, Claudia

2017-11-01

In 2015, we investigated Bartonella quintana and typhus group rickettsiae in body lice from homeless persons in Bogotá, Colombia. We found B. quintana-infected body lice and seroprevalence of this microorganism in 19% of homeless persons and typhus group rickettsiae in 56%. Public health professionals should start preemptive measures and active vector control.

Spotted fever group rickettsiae in ticks of migratory birds in Romania.

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Mărcuţan, Ioan-Daniel; Kalmár, Zsuzsa; Ionică, Angela Monica; D'Amico, Gianluca; Mihalca, Andrei Daniel; Vasile, Cozma; Sándor, Attila D

2016-05-20

Birds are important hosts and dispersers of parasitic arthropods and vector-borne zoonotic pathogens. Particularly migratory species may carry these parasites over long distances in short time periods. Migratory hotspots present ideal conditions to get a snapshot of parasite and pathogen diversity of birds migrating between continents. The aim of this study was to investigate the presence and diversity of Rickettsia spp. in ticks collected from birds at a migratory hot-spot in the Danube Delta, Romania, eastern Europe. DNA was extracted from ticks that were collected from migratory birds in the Danube Delta during migratory seasons in 2011-2012. Two 360 bp  fragments of the 16S ribosomal RNA gene and a 381 bp  fragment Gene gltA were PCR amplified and analyzed by sequence analysis (performed at Macrogen Europe, Amsterdam, The Netherlands). Nucleotide sequences were compared to reference sequences available in the GenBank database, using Basic Local Alignment Search Tool. Four hundred ticks of four different species were found on 11 bird species. The prevalence of Rickettsia spp. infection was 14 % (56/400, CI: 11.7-29.1), with significantly more nymphs hosting rickettsial infection compared to larvae (48 vs 7; P birds migrating through eastern Europe may carry ticks infected with a high diversity of rickettsial pathogens, with four Rickettsia spp. recorded. Migratory direction was important for pathogen burden, with seasonal differences in the occurrence of individual Rickettsia species. Here we report the first individual records of different Rickettsia spp. in H. concinna (R. monacensis), I. arboricola (R. helvetica, R. massiliae) and I. redikorzevi (R. helvetica) and also the first geographical record of occurrence of R. massiliae in Romania, representing the easternmost observation on the continent.

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

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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.

Rickettsia sibirica mongolitimonae Infection, Turkey, 2016.

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Kuscu, Ferit; Orkun, Omer; Ulu, Aslihan; Kurtaran, Behice; Komur, Suheyla; Inal, A Seza; Erdogan, Damla; Tasova, Yesim; Aksu, Hasan S Z

2017-07-01

In 2016, Rickettsia sibirica mongolitimonae was diagnosed for a man in Turkey. He had been bitten by a Hyalomma marginatum tick, from which PCR detected rickettsial DNA. Sequence analysis of the DNA identified R. sibirica mongolitimonae. Immunofluorescence assay of patient serum indicated R. conorii, which cross-reacts. PCR is recommended for rickettsiosis diagnoses.

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

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

2011-01-01

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

Genetic variability of Rickettsia spp. in Ixodes persulcatus ticks from continental and island areas of the Russian Far East.

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Igolkina, Y; Bondarenko, E; Rar, V; Epikhina, T; Vysochina, N; Pukhovskaya, N; Tikunov, A; Ivanov, L; Golovljova, I; Ivanov, М; Tikunova, N

2016-10-01

Rickettsia spp. are intracellular Gram-negative bacteria transmitted by arthropods. Two potentially pathogenic rickettsiae, Candidatus Rickettsia tarasevichiae and Rickettsia helvetica, have been found in unfed adult Ixodes persulcatus ticks. The aim of this study was to assess the prevalence and genetic variability of Rickettsia spp. in I. persulcatus ticks collected from different locations in the Russian Far East. In total, 604 adult I. persulcatus ticks collected from four sites in the Khabarovsk Territory (continental area) and one site in Sakhalin Island were examined for the presence of Rickettsia spp. by real-time PCR. Nested PCR with species-specific primers and sequencing were used for genotyping of revealed rickettsiae. The overall prevalence of Rickettsia spp. in ticks collected in different sites varied from 67.9 to 90.7%. However, the proportion of different Rickettsia species observed in ticks from Sakhalin Island significantly differed from that in ticks from the Khabarovsk Territory. In Sakhalin Island, R. helvetica prevailed in examined ticks, while Candidatus R. tarasevichiae was predominant in the Khabarovsk Territory. For gltA and ompB gene fragments, the sequences obtained for Candidatus R. tarasevichiae from all studied sites were identical to each other and to the known sequences of this species. According to sequence analysis of gltA, оmpB and sca4 genes, R. helvetica isolates from Sakhalin Island and the Khabarovsk Territory were identical to each other, but they differed from R. helvetica from other regions and from those found in other tick species. For the first time, DNA of pathogenic Rickettsia heilongjiangensis was detected in I. persulcatus ticks in two sites from the Khabarovsk Territory. The gltA, ompA and оmpB gene sequences of R. heilongjiangensis were identical to or had solitary mismatches with the corresponding sequences of R. heilongjiangensis found in other tick species. Copyright © 2016 Elsevier GmbH. All rights

Molecular detection of Bartonella spp. and Rickettsia spp. in bat ectoparasites in Brazil.

Science.gov (United States)

do Amaral, Renan Bressianini; Lourenço, Elizabete Captivo; Famadas, Kátia Maria; Garcia, Amanda Barbosa; Machado, Rosangela Zacarias; André, Marcos Rogério

2018-01-01

The family Streblidae comprises a monophyletic group of Hippoboscoidea, hematophagous dipterans that parasitize bats. Bartonella spp. and Rickettsia spp. have been reported in bats sampled in Europe, Africa, Asia, North, Central and South America. However, there are few reports on the Bartonella and Rickettsia bacteria infecting Hippoboscoidea flies and mites. While Spinturnicidae mites are ectoparasites found only in bats, those belonging to the family Macronyssidae comprise mites that also parasitize other mammal species. This study investigates the occurrence and assesses the phylogenetic positioning of Bartonella spp. and Rickettsia spp. found in Streblidae flies and Spinturnicidae and Macronyssidae mites collected from bats captured in Brazil. From May 2011 to April 2012 and September 2013 to December 2014, 400 Streblidae flies, 100 Macronyssidaes, and 100 Spinturnicidae mites were collected from bats captured in two sites in northeastern Nova Iguaçu, Rio de Janeiro, southeastern Brazil. Forty (19.8%) out of 202 Streblidae flies were positive for Bartonella spp. in qPCR assays based on the nuoG gene. Among the flies positive for the bacterium, six (18%) were Paratrichobius longicrus, seven (29%) Strebla guajiro, two (40%) Aspidoptera phyllostomatis, five (11%) Aspidoptera falcata, one (10%) Trichobius anducei, one (25%) Megistopoda aranea, and 18 (32%) Trichobius joblingi, and collected from bats of the following species: Artibeus lituratus, Carollia perspicillata, Artibeus planirostris, Sturnira lilium, and Artibeus obscurus. Six sequences were obtained for Bartonella (nuoG [n = 2], gltA [n = 2], rpoB [n = 1], ribC = 1]). The phylogenetic analysis based on gltA (750pb) gene showed that the Bartonella sequences clustered with Bartonella genotypes detected in bats and ectoparasites previously sampled in Latin America, including Brazil. Only one sample (0.49%) of the species Trichobius joblingi collected from a specimen of Carollia perspicillata was positive

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

International Nuclear Information System (INIS)

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

1982-01-01

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

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

Czech Academy of Sciences Publication Activity Database

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: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.690, year: 2015

New Rickettsia species in soft ticks Ornithodoros hasei collected from bats in French Guiana.

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Tahir, Djamel; Socolovschi, Cristina; Marié, Jean-Lou; Ganay, Gautier; Berenger, Jean-Michel; Bompar, Jean-Michel; Blanchet, Denis; Cheuret, Marie; Mediannikov, Oleg; Raoult, Didier; Davoust, Bernard; Parola, Philippe

2016-10-01

In French Guiana, located on the northeastern coast of South America, bats of different species are very numerous. The infection of bats and their ticks with zoonotic bacteria, especially Rickettsia species, is so far unknown. In order to improve knowledge of these zoonotic pathogens in this French overseas department, the presence and diversity of tick-borne bacteria was investigated with molecular tools in bat ticks. In the beginning of 2013, 32 bats were caught in Saint-Jean-du-Maroni, an area close to the coast of French Guiana, and the ticks of these animals were collected. A total of 354 larvae of Argasidae soft ticks (Ornithodoros hasei) from 12 bats (Noctilio albiventris) were collected and 107 of them were analysed. DNA was extracted from the samples and quantitative real-time PCR was carried out to detect Rickettsia spp., Bartonella spp., Borrelia spp. and Coxiella burnetii. All tested samples were negative for Bartonella spp., Borrelia spp. and Coxiella burnetii. Rickettsia DNA was detected in 31 (28.9%) ticks. An almost entire (1118 base pairs long) sequence of the gltA gene was obtained after the amplification of some positive samples on conventional PCR and sequencing. A Bayesian tree was constructed using concatenated rrs, gltA, ompA, ompB, and gene D sequences. The study of characteristic sequences shows that this Rickettsia species is very close (98.3-99.8%) genetically to R. peacockii. Nevertheless, the comparative analysis of sequences obtained from gltA, ompA, ompB, rrs and gene D fragments demonstrated that this Rickettsia is different from the other members of the spotted fever group. The sequences of this new species were deposited in GenBank as Candidatus Rickettsia wissemanii. This is the first report showing the presence of nucleic acid of Rickettsia in Ornithodoros hasei ticks from South American bats. Copyright © 2016 Elsevier GmbH. All rights reserved.

Multispacer typing of Rickettsia isolates from humans and ticks in Tunisia revealing new genotypes.

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Znazen, Abir; Khrouf, Fatma; Elleuch, Nihel; Lahiani, Dorra; Marrekchi, Chakib; M'Ghirbi, Youmna; Ben Jemaa, Mounir; Bouattour, Ali; Hammami, Adnene

2013-12-31

Rickettsioses are important remerging vector born infections. In Tunisia, many species have been described in humans and vectors. Genotyping is important for tracking pathogen movement between hosts and vectors. In this study, we characterized Rickettsia species detected in patients and vectors using multispacer typing (MST), proposed by Founier et al. and based on three intergenic spacers (dksA-xerC, rmpE- tRNA(fMet), mppA-pruC) sequencing. Our study included 25 patients hospitalized during 2009. Ticks and fleas were collected in the vicinity of confirmed cases. Serology was performed on serum samples by microimmunofluorescence using Rickettsia conorii and Rickettsia typhi antigens. To detect and identify Rickettsia species, PCR targeting ompA, ompB and gltA genes followed by sequencing was performed on 18 obtained skin biopsies and on all collected vectors. Rickettsia positive samples were further characterized using primers targeting three intergenic spacers (dksA-xerC, rmpE- tRNA(fMet) and mppA-purC). A rickettsial infection was confirmed in 15 cases (60%). Serology was positive in 13 cases (52%). PCR detected Rickettsia DNA in four biopsies (16%) allowing the identification of R. conorii subsp israelensis in three cases and R. conorii subsp conorii in one case. Among 380 collected ticks, nine presented positive PCR (2.4%) allowing the identification of six R. conorii subsp israelensis, two R. massiliae and one R. conorii subsp conorii. Among 322 collected fleas, only one was positive for R. felis. R. conorii subsp israelensis strains detected in humans and vectors clustered together and showed a new MST genotype. Similarly, R. conorii subsp conorii strains detected in a skin biopsy and a tick were genetically related and presented a new MST genotype. New Rickettsia spotted fever strain genotypes were found in Tunisia. Isolates detected in humans and vectors were genetically homogenous despite location differences in their original isolation suggesting

Identification and molecular characterization of spotted fever group rickettsiae in ticks collected from farm ruminants in Lebanon.

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Fernández de Mera, Isabel G; Blanda, Valeria; Torina, Alessandra; Dabaja, Mayssaa Fawaz; El Romeh, Ali; Cabezas-Cruz, Alejandro; de la Fuente, José

2018-01-01

Tick-borne diseases have become a world health concern, emerging with increasing incidence in recent decades. Spotted fever group (SFG) rickettsiae are tick-borne pathogens recognized as important agents of human tick-borne diseases worldwide. In this study, 88 adult ticks from the species Hyalomma anatolicum, Rhipicephalus annulatus, Rh. bursa, Rh. sanguineus sensu lato, and Rh. turanicus, were collected from farm ruminants in Lebanon, and SFG rickettsiae were molecularly identified and characterized in these ticks. The screening showed a prevalence of 68% for Rickettsia spp., including the species R. aeschlimannii, R. africae, R. massiliae and Candidatus R. barbariae, the latter considered an emerging member of the SFG rickettsiae. These findings contribute to a better knowledge of the distribution of these pathogens and demonstrate that SFG rickettsiae with public health relevance are found in ticks collected in Lebanon, where the widespread distribution of tick vectors and possible livestock animal hosts in contact with humans may favor transmission to humans. Few reports exist for some of the tick species identified here as being infected with SFG Rickettsia. Some of these tick species are proven vectors of the hosted rickettsiae, although this information is unknown for other of these species. Therefore, these results suggested further investigation on the vector competence of the tick species with unknown role in transmission of some of the pathogens identified in this study. Copyright © 2017 Elsevier GmbH. All rights reserved.

Serological and molecular evidence for spotted fever group Rickettsia and Borrelia burgdorferi sensu lato co-infections in The Netherlands

NARCIS (Netherlands)

Koetsveld, Joris; Tijsse-Klasen, Ellen; Herremans, Tineke; Hovius, Joppe W. R.; Sprong, Hein

2016-01-01

Only a few reported cases indicate that Rickettsia helvetica and Rickettsia monacensis can cause disease in humans. Exposure to these two spotted fever group (SFG) rickettsiae occurs through bites of Ixodes ricinus, also the primary vector of Lyme borreliosis in Europe. To date, it is unclear how

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

Science.gov (United States)

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

1993-12-01

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

Shell-vial culture, coupled with real-time PCR, applied to Rickettsia conorii and Rickettsia massiliae-Bar29 detection, improving the diagnosis of the Mediterranean spotted fever.

Science.gov (United States)

Segura, Ferran; Pons, Immaculada; Sanfeliu, Isabel; Nogueras, María-Mercedes

2016-04-01

Rickettsia conorii and Rickettsia massiliae-Bar29 are related to Mediterranean spotted fever (MSF). They are intracellular microorganisms. The Shell-vial culture assay (SV) improved Rickettsia culture but it still has some limitations: blood usually contains low amount of microorganisms and the samples that contain the highest amount of them are non-sterile. The objectives of this study were to optimize SV culture conditions and monitoring methods and to establish antibiotic concentrations useful for non-sterile samples. 12 SVs were inoculated with each microorganism, incubated at different temperatures and monitored by classical methods and real-time PCR. R. conorii was detected by all methods at all temperatures since 7th day of incubation. R. massiliae-Bar29 was firstly observed at 28°C. Real-time PCR allowed to detected it 2-7 days earlier (depend on temperature) than classical methods. Antibiotics concentration needed for the isolation of these Rickettsia species from non-sterile samples was determined inoculating SV with R. conorii, R. massiliae-Bar29, biopsy or tick, incubating them with different dilutions of antibiotics and monitoring them weekly. To sum up, if a MSF diagnosis is suspected, SV should be incubated at both 28°C and 32°C for 1-3 weeks and monitored by a sensitive real-time PCR. If the sample is non-sterile the panel of antibiotics tested can be added. Copyright © 2016 Elsevier GmbH. All rights reserved.

Rickettsia Detected in the Reptile Tick Bothriocroton hydrosauri from the Lizard Tiliqua rugosa in South Australia

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Harriet Whiley

2016-06-01

Full Text Available Rickettsiosis is a potentially fatal tick borne disease. It is caused by the obligate intracellular bacteria Rickettsia, which is transferred to humans through salivary excretions of ticks during the biting process. Globally, the incidence of tick-borne diseases is increasing; as such, there is a need for a greater understanding of tick–host interactions to create more informed risk management strategies. Flinders Island spotted fever rickettsioses has been identified throughout Australia (Tasmania, South Australia, Queensland and Torres Strait Islands with possible identifications in Thailand, Sri Lanka and Italy. Flinders Island spotted fever is thought to be spread through tick bites and the reptile tick Bothriocroton hydrosauri has been implicated as a vector in this transmission. This study used qPCR to assay Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard hosts on mainland South Australia near where spotted fever cases have been identified. We report that, although we discovered Rickettsia in all tick samples, it was not Rickettsia honei. This study is the first to use PCR to positively identify Rickettsia from South Australian Bothriocroton hydrosauri ticks collected from Tiliqua rugosa (sleepy lizard hosts. These findings suggest that B. hydrosauri may be a vector of multiple Rickettsia spp. Also as all 41 tested B. hydrosauri ticks were positive for Rickettsia this indicates an extremely high prevalence within the studied area in South Australia.

Pathogenesis of Cell Injury by Rickettsia conorii.

Science.gov (United States)

1984-06-15

infected soldiers in the Viet Nam War. These rickettsiae have continued to attract research support. Although R. conorii has received far less...principally for reasons of location related to cosmetic concern or proximity to vital structures, e.g., carotid artery. Other patients had boutonneuse fever

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

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Roderick F Felsheim

2009-12-01

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

Isolamento de Rickettsia em cultura de células vero

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Melles Heloisa Helena Barbosa

1999-01-01

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.

High Prevalence of Rickettsia spp. in Dog Fleas (Siphonaptera: Pulicidae) in Rural Uganda.

Science.gov (United States)

Palomar, Ana M; Cevidanes, Aitor; Portillo, Aránzazu; Kalema-Zikusoka, Gladis; Chirife, Andrea D; Romero, Lourdes; Muro, Jesús; Mugisha, Lawrence; Oteo, José A; Millán, Javier

2017-07-01

Fleas are known vectors of zoonotic agents. Thirty-five fleas, including 28 Ctenocephalides felis (Bouché), four Pulex irritans (L.), and three Echidnophaga gallinacea (Westwood) from 19 rural dogs from southwestern Uganda were analyzed for the presence of Rickettsia spp. (ompB, gltA, and 17 kDa fragment genes) and Bartonella spp. (rpoB and ITS genes) by PCR. Rickettsial DNA was detected in 27 out of 28 of Ct. felis and in two out of four P. irritans. None of the E. gallinacea specimens harbored Rickettsia DNA. Rickettsia felis was confirmed in 12 Ct. felis and in the two P. irritans specimens with positive PCR-results. In addition, the presence of Candidatus Rickettsia asemboensis was evidenced in 15 Ct. felis. Bartonella spp. was not amplified in any sample. Our survey indicates that R. felis, the agent of the flea-borne spotted fever, is present in the study area. Besides, this is the first description of Ca. R. asemboensis in Uganda. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Molecular diagnostics of Rickettsia africae infection in travelers returning from South Africa to The Netherlands

NARCIS (Netherlands)

Wieten, Rosanne W.; Hovius, Joppe W. R.; Groen, Emilie J.; van der Wal, Allard C.; de Vries, Peter J.; Beersma, Matthijs F. C.; Tijsse-Klasen, Ellen; Sprong, Hein; Grobusch, Martin P.

2011-01-01

African tick-bite fever (ATBF) is frequently diagnosed in The Netherlands in travelers returning from South Africa. It is caused by Rickettsia africae and diagnosis is based on travel history and clinical presentation and usually confirmed by detecting serum antibodies against rickettsiae of the

JST Thesaurus Headwords and Synonyms: Rickettsia [MeCab user dictionary for science technology term[Archive

Lifescience Database Archive (English)

Full Text Available MeCab user dictionary for science technology term Rickettsia 名詞 一般 * * * * リケッチア属 リケッチアゾク リケッチアゾク Thesaurus2015 200906036464977172 C LS07 UNKNOWN_1 Rickettsia

Detection of a typhus group Rickettsia in Amblyomma ticks in the state of Nuevo Leon, Mexico.

Science.gov (United States)

Medina-Sanchez, Aaron; Bouyer, Donald H; Alcantara-Rodriguez, Virginia; Mafra, Claudio; Zavala-Castro, Jorge; Whitworth, Ted; Popov, Vsevolod L; Fernandez-Salas, Ildefonso; Walker, David H

2005-12-01

The state of Nuevo Leon, Mexico has had outbreaks of typhus group rickettsiosis, most recently recognized in 1997. Evaluation of the sera of 345 patients with a dengue-like illness revealed that 25.5% had antibodies reactive with typhus group rickettsiae and 16% had antibodies to Rickettsia parkeri. Rickettsiae were detected by PCR and shell-vial isolations in the field-collected Amblyomma ticks. Molecular characterization by DNA sequence analysis of the gltA, ompB, and 17-kDa gene identified the organisms to be R. prowazekii.

Differences in Intracellular Fate of Two Spotted Fever Group Rickettsia in Macrophage-Like Cells.

Science.gov (United States)

Curto, Pedro; Simões, Isaura; Riley, Sean P; Martinez, Juan J

2016-01-01

Spotted fever group (SFG) rickettsiae are recognized as important agents of human tick-borne diseases worldwide, such as Mediterranean spotted fever (Rickettsia conorii) and Rocky Mountain spotted fever (Rickettsia rickettsii). Recent studies in several animal models have provided evidence of non-endothelial parasitism by pathogenic SFG Rickettsia species, suggesting that the interaction of rickettsiae with cells other than the endothelium may play an important role in pathogenesis of rickettsial diseases. These studies raise the hypothesis that the role of macrophages in rickettsial pathogenesis may have been underappreciated. Herein, we evaluated the ability of two SFG rickettsial species, R. conorii (a recognized human pathogen) and Rickettsia montanensis (a non-virulent member of SFG) to proliferate in THP-1 macrophage-like cells, or within non-phagocytic cell lines. Our results demonstrate that R. conorii was able to survive and proliferate in both phagocytic and epithelial cells in vitro. In contrast, R. montanensis was able to grow in non-phagocytic cells, but was drastically compromised in the ability to proliferate within both undifferentiated and PMA-differentiated THP-1 cells. Interestingly, association assays revealed that R. montanensis was defective in binding to THP-1-derived macrophages; however, the invasion of the bacteria that are able to adhere did not appear to be affected. We have also demonstrated that R. montanensis which entered into THP-1-derived macrophages were rapidly destroyed and partially co-localized with LAMP-2 and cathepsin D, two markers of lysosomal compartments. In contrast, R. conorii was present as intact bacteria and free in the cytoplasm in both cell types. These findings suggest that a phenotypic difference between a non-pathogenic and a pathogenic SFG member lies in their respective ability to proliferate in macrophage-like cells, and may provide an explanation as to why certain SFG rickettsial species are not associated

Limited transcriptional responses of Rickettsia rickettsii exposed to environmental stimuli.

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Damon W Ellison

Full Text Available Rickettsiae are strict obligate intracellular pathogens that alternate between arthropod and mammalian hosts in a zoonotic cycle. Typically, pathogenic bacteria that cycle between environmental sources and mammalian hosts adapt to the respective environments by coordinately regulating gene expression such that genes essential for survival and virulence are expressed only upon infection of mammals. Temperature is a common environmental signal for upregulation of virulence gene expression although other factors may also play a role. We examined the transcriptional responses of Rickettsia rickettsii, the agent of Rocky Mountain spotted fever, to a variety of environmental signals expected to be encountered during its life cycle. R. rickettsii exposed to differences in growth temperature (25 degrees C vs. 37 degrees C, iron limitation, and host cell species displayed nominal changes in gene expression under any of these conditions with only 0, 5, or 7 genes, respectively, changing more than 3-fold in expression levels. R. rickettsii is not totally devoid of ability to respond to temperature shifts as cold shock (37 degrees C vs. 4 degrees C induced a change greater than 3-fold in up to 56 genes. Rickettsiae continuously occupy a relatively stable environment which is the cytosol of eukaryotic cells. Because of their obligate intracellular character, rickettsiae are believed to be undergoing reductive evolution to a minimal genome. We propose that their relatively constant environmental niche has led to a minimal requirement for R. rickettsii to respond to environmental changes with a consequent deletion of non-essential transcriptional response regulators. A minimal number of predicted transcriptional regulators in the R. rickettsii genome is consistent with this hypothesis.

A Case of Human Infection by Rickettsia slovaca in Greece.

Science.gov (United States)

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.

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.

Science.gov (United States)

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.

Serological and molecular detection of spotted fever group Rickettsia in a group of pet dogs from Luanda, Angola.

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Barradas, Patrícia F; Vilhena, Hugo; Oliveira, Ana Cristina; Granada, Sara; Amorim, Irina; Ferreira, Paula; Cardoso, Luís; Gärtner, Fátima; de Sousa, Rita

2017-05-31

Infections with tick-borne rickettsiae can cause diseases well known in humans but still not so well characterized in dogs. Susceptibility to infection depends on the virulence of Rickettsia spp. and only a few of them have been described to cause disease in dogs. The aim of this study was to investigate the exposure to Rickettsia spp. among a group of pet dogs from Luanda, Angola. Out of 103 dogs included in the study, 62 (60.2%) were infested with ticks. Plasma specimens tested for serology by an immunofluorescence assay (IFA) revealed that six (5.8%) dogs had detectable immunoglobulin G (IgG) antibodies to spotted fever group Rickettsia (SFGR), with endpoint titers of 64 for two dogs, 128 for three dogs and 1024 for one dog. From the seropositive group of dogs, five (83%) of them were males, with their age ranging from 1 to 8 years old. Among the seropositive dogs, four (66.7%) were parasitized with ticks and no breed (or cross) was found to be associated with specific antibodies. Rickettsia spp. DNA was detected by nested-polymerase chain reaction (PCR) in two (1.9%) dogs that were found to be seronegative. Seroprevalence and molecular detection of Rickettsia spp. infection in this group of pet dogs from Luanda is low compared with other studies performed in the same type of hosts in other areas. Although many dogs were parasitized with ticks, a low prevalence of Rickettsia spp. could be related with the hypothesis of a low rickettsial prevalence in the infesting ticks. This study provides evidence that dogs in Luanda are exposed to Rickettsia spp., but further studies are needed to better characterize the bacterial infections in dogs and in their ectoparasites.

Use of immunoradiometric analysis to determine Rickettsia antigens in cell cultures and chick embryos

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Prozorovskiy, S.V.; Alekseeva, N.V.; Knyazeva, E.N.; Ignatovich, V.F.; Barkhatova, O.T.

1984-02-01

A modification of an immunoradiometric analysis to determine Rickettsia antigens in various biological substrates was studied, using rickettsious diagnostricums, egg and cell cultures of Rickettsia. The method was highly sensitive for the determination of minimal quantities of antigens in these substrates. The method appears to be promising for studies related to the detection of microorganisms and their antigens. 5 references.

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

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Maurício C Horta

2007-11-01

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

Rickettsia sibirica mongolitimonae Infection, France, 2010-2014.

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Angelakis, Emmanouil; Richet, Herve; Raoult, Didier

2016-05-01

To further characterize human infections caused by Rickettsia sibirica mongolitimonae, we tested skin biopsy and swab samples and analyzed clinical, epidemiologic, and diagnostic characteristics of patients with a rickettsiosis. The most common (38%) indigenous species was R. sibirica mongolitimonae. Significantly more cases of R. sibirica mongolitimonae infection occurred during spring and summer.

Anaplasma, Ehrlichia and Rickettsia species infections in cats

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Pennisi, Maria Grazia; Hofmann-Lehmann, Regina; Radford, Alan D; Tasker, Séverine; Belák, Sándor; Addie, Diane D; Boucraut-Baralon, Corine; Egberink, Herman; Frymus, Tadeusz; Gruffydd-Jones, Tim; Hartmann, Katrin; Horzinek, Marian C; Hosie, Margaret J; Lloret, Albert; Lutz, Hans; Marsilio, Fulvio; Thiry, Etienne; Truyen, Uwe; Möstl, Karin

2017-01-01

OVERVIEW: Anaplasma species, Ehrlichia species and Rickettsia species are vector-borne pathogens infecting a wide variety of mammals, but causing disease in very few of them. Infection in cats: Anaplasma phagocytophilum is the most important feline pathogen among these rickettsial organisms, and

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

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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.

Seroprevalence of spotted fever group (SFG) rickettsiae infection in domestic ruminants in Khartoum State, Sudan.

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Eisawi, Nagwa M; Hassan, Dina A; Hussien, Mohammed O; Musa, Azza B; El Hussein, Abdel Rahim M

2017-05-01

Spotted fever group (SFG) rickettsiosis is caused by obligatory intracellular Gram-negative bacteria that belong to the genus Rickettsia . Ticks belonging to the family Ixodidae can act as vectors, reservoirs or amplifiers of SFG rickettsiae. This study was conducted to estimate the seroprevalence of SFG rickettsioses in cattle, sheep and goats from Khartoum State, Sudan. Blood samples were collected from a total of 600 animals (sheep, goats and cattle) from 32 different farms distributed in three locations in Khartoum State during the period January to December 2012. Sera were tested for antibodies against SFG rickettsiae using IFAT. The prevalence of seropositivity was 59.3% in sheep, 60.1% in goats and 64.4% in cattle. Season was significantly ( P <  0.05) associated with seroprevalence of SFG rickettsiae in cattle during winter. The SFG rickettsiae antibodies prevalence was significantly higher in female compared with male in sheep, but there were no significant differences between male and female in either cattle or goats. The prevalence was significantly higher in adult animals compared with young in both sheep and goats. With regard to management system, there was a significant difference in the prevalence in cattle raised in closed system compared with those raised in semi-intensive system. In contrast, there was significant difference in the seroprevalence of SFG in sheep where the prevalence was higher in the sheep raised in semi-intensive system compared with those raised in close system. There was no significant difference in the seroprevalence in goats with regard to management systems. The unexpected high prevalence of SFG rickettsia antibodies in domestic ruminants sera suggest that the veterinary and public health impact of these agents in Sudan need further evaluation especially in humans.

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

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Bodnar, James; Mortazavi, Bobak; Laurent, Timothy; Deason, Jeff; Thephavongsa, Khanhkeo; Zhong, Jianmin

2015-01-01

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. PMID:26650541

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

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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

First report of Rickettsia raoultii and R. slovaca in Melophagus ovinus, the sheep ked.

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Liu, Dan; Wang, Yuan-Zhi; Zhang, Huan; Liu, Zhi-Qiang; Wureli, Ha-Zi; Wang, Shi-Wei; Tu, Chang-Chun; Chen, Chuang-Fu

2016-11-25

Melophagus ovinus (Diptera: Hippoboscidae), a hematophagous ectoparasite, is mainly found in Europe, Northwestern Africa, and Asia. This wingless fly infests sheep, rabbits, and red foxes, and causes inflammation, wool loss and skin damage. Furthermore, this parasite has been shown to transmit diseases, and plays a role as a vector. Herein, we investigated the presence of various Rickettsia species in M. ovinus. In this study, a total of 95 sheep keds were collected in Kuqa County and Alaer City southern region of Xinjiang Uygur Autonomous Region, northwestern China. First, collected sheep keds were identified on the species level using morphological keys and molecular methods based on a fragment of the 18S ribosomal DNA gene (18S rDNA). Thereafter, to assess the presence of rickettsial DNA in sheep keds, the DNA of individual samples was screened by PCR based on six Rickettsia-specific gene fragments originating from six genes: the 17-kilodalton antigen gene (17-kDa), 16S rRNA gene (rrs), surface cell antigen 4 gene (sca4), citrate synthase gene (gltA), and outer membrane protein A and B genes (ompA and ompB). The amplified products were confirmed by sequencing and BLAST analysis ( https://blast.ncbi.nlm.nih.gov/Blast.cgi?PROGRAM=blastn&PAGE_TYPE=BlastSearch&LINK_LOC=blasthome ). According to its morphology and results of molecular analysis, the species was identified as Melophagus ovinus, with 100% identity to M. ovinus from St. Kilda, Australia (FN666411). DNA of Rickettsia spp. were found in 12 M. ovinus samples (12.63%, 12/95). Rickettsia raoultii and R. slovaca were confirmed based on phylogenetic analysis, although the genetic markers of these two rickettsial agents amplified in this study showed molecular diversity. This is the first report of R. raoultii and R. slovaca DNA in M. ovinus. Rickettsia slovaca was found for the first time around the Taklimakan Desert located in China. This finding extends the geographical range of spotted fever group

First report of Rickettsia raoultii and R. slovaca in Melophagus ovinus, the sheep ked

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Dan Liu

2016-11-01

Full Text Available Abstract Background Melophagus ovinus (Diptera: Hippoboscidae, a hematophagous ectoparasite, is mainly found in Europe, Northwestern Africa, and Asia. This wingless fly infests sheep, rabbits, and red foxes, and causes inflammation, wool loss and skin damage. Furthermore, this parasite has been shown to transmit diseases, and plays a role as a vector. Herein, we investigated the presence of various Rickettsia species in M. ovinus. Methods In this study, a total of 95 sheep keds were collected in Kuqa County and Alaer City southern region of Xinjiang Uygur Autonomous Region, northwestern China. First, collected sheep keds were identified on the species level using morphological keys and molecular methods based on a fragment of the 18S ribosomal DNA gene (18S rDNA. Thereafter, to assess the presence of rickettsial DNA in sheep keds, the DNA of individual samples was screened by PCR based on six Rickettsia-specific gene fragments originating from six genes: the 17-kilodalton antigen gene (17-kDa, 16S rRNA gene (rrs, surface cell antigen 4 gene (sca4, citrate synthase gene (gltA, and outer membrane protein A and B genes (ompA and ompB. The amplified products were confirmed by sequencing and BLAST analysis ( https://blast.ncbi.nlm.nih.gov/Blast.cgi?PROGRAM=blastn&PAGE_TYPE=BlastSearch&LINK_LOC=blasthome . Results According to its morphology and results of molecular analysis, the species was identified as Melophagus ovinus, with 100% identity to M. ovinus from St. Kilda, Australia (FN666411. DNA of Rickettsia spp. were found in 12 M. ovinus samples (12.63%, 12/95. Rickettsia raoultii and R. slovaca were confirmed based on phylogenetic analysis, although the genetic markers of these two rickettsial agents amplified in this study showed molecular diversity. Conclusions This is the first report of R. raoultii and R. slovaca DNA in M. ovinus. Rickettsia slovaca was found for the first time around the Taklimakan Desert located in China. This finding

Serological and molecular evidence for spotted fever group Rickettsia and Borrelia burgdorferi sensu lato co-infections in The Netherlands.

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Koetsveld, Joris; Tijsse-Klasen, Ellen; Herremans, Tineke; Hovius, Joppe W R; Sprong, Hein

2016-03-01

Only a few reported cases indicate that Rickettsia helvetica and Rickettsia monacensis can cause disease in humans. Exposure to these two spotted fever group (SFG) rickettsiae occurs through bites of Ixodes ricinus, also the primary vector of Lyme borreliosis in Europe. To date, it is unclear how often exposure to these two microorganisms results in infection or disease. We show that of all the Borrelia burgdorferi s.l.-positive ticks, 25% were co-infected with rickettsiae. Predominantly R. helvetica was detected while R. monacensis was only found in approximately 2% of the ticks. In addition, exposure to tick-borne pathogens was compared by serology in healthy blood donors, erythema migrans (EM)-patients, and patients suspected of Lyme neuroborreliosis (LNB). As could be expected, seroreactivity against B. burgdorferi sensu lato was lower in blood donors (6%) compared to EM patients (34%) and suspected LNB cases (64%). Interestingly, seroreactivity against SFG Rickettsia antigens was not detected in serum samples from blood donors (0%), but 6% of the EM patients and 21% of the LNB suspects showed anti-rickettsial antibodies. Finally, the presence of B. burgdorferi s.l. and Rickettsia spp. in cerebrospinal fluid samples of a large cohort of patients suspected of LNB (n=208) was investigated by PCR. DNA of B. burgdorferi s.l., R. helvetica and R. monacensis was detected in seventeen, four and one patient, respectively. In conclusion, our data show that B. burgdorferi s.l. and SFG rickettsiae co-infection occurs in Dutch I. ricinus and that Lyme borreliosis patients, or patients suspected of Lyme borreliosis, are indeed exposed to both tick-borne pathogens. Whether SFG rickettsiae actually cause disease, and whether co-infections alter the clinical course of Lyme borreliosis, is not clear from our data, and warrants further investigation. Copyright © 2015 Elsevier GmbH. All rights reserved.

Investigations on Rickettsia in Ticks at the Sino-Russian and Sino-Mongolian Borders, China.

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Liu, Lijuan; Chen, Qian; Yang, Yu; Wang, Jiancheng; Cao, Xiaomei; Zhang, Sheng; Li, Hong; Hou, Yong; Wang, Fuxiang; Xu, Baoliang

2015-12-01

To describe the prevalence of Rickettsia in ticks at the Sino-Russian and Sino-Mongolian borders, a total of 292 ticks were collected and tested by conventional PCR assays. The prevalence of Rickettsia was 53.4%, and phylogenetic analysis showed that they belonged to R. raoultii species after alignment for the ompA, ompB, and gltA genes, respectively. Coxiella burnetii DNA was detected for 14%, and no Ehrlichia, Borrelia burgdorferi, and Babesia species were found. Co-infection of two pathogens was 9.9%, and no co-infection with three or more pathogens was found. This study suggested Rickettsia was the most common pathogen in the ticks and co-infection was found. The findings might be helpful to provide advice on the prevention and control of tick-borne disease potential for tourists and residents.

Dynamics of Exposure to Rickettsia parkeri in Cattle in the Paraná River Delta, Argentina.

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Monje, L D; Costa, F B; Colombo, V C; Labruna, M B; Antoniazzi, L R; Gamietea, I; Nava, S; Beldomenico, P M

2016-05-01

Several cases of human rickettsiosis caused by Rickettsia parkeri were recently documented in the Paraná River delta of Argentina, where the tick vector is Amblyomma triste Koch. As cattle suffer recurrent A. triste infestations, they are at risk of becoming infected with R. parkeri Herein we investigated the dynamics of R. parkeri and its A. triste vector in a herd of beef cattle. Cattle were followed for 18 mo and samples were analyzed for the presence of antibodies against four Rickettsia species (R. parkeri, Rickettsia bellii, Rickettsia amblyommii, and Rickettsia felis) and also for the presence of rickettsial DNA. Additionally, cattle were examined for attached ticks and questing adult ticks were collected. All ticks were analyzed for the presence of rickettsial DNA. No evidence of rickettsemia was found in any cow, but the high R. parkeri infection rate documented in A. triste both questing in the study area (13.9%) and feeding on cattle (19.8%) and the identification of antibodies against R. parkeri antigen in 90% of cattle are evidence that infection is taking place. Altogether, our data suggest that A. triste ticks are capable of naturally exposing cattle to R. parkeri However, the progress of R. parkeri infection and its impact on bovine health and production remain to be established. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Molecular evidence of Rickettsia spp. in ixodid ticks and rodents in suburban, natural and rural habitats in Slovakia.

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Minichová, Lenka; Hamšíková, Zuzana; Mahríková, Lenka; Slovák, Mirko; Kocianová, Elena; Kazimírová, Mária; Škultéty, Ľudovít; Štefanidesová, Katarína; Špitalská, Eva

2017-03-24

Natural foci of tick-borne spotted fever group (SFG) rickettsiae of public health concern have been found in Slovakia, but the role of rodents in their circulation is unclear. Ticks (Ixodes ricinus, Ixodes trianguliceps, Dermacentor marginatus, Dermacentor reticulatus, Haemaphysalis concinna and Haemaphysalis inermis) and tissues of rodents (Apodemus flavicollis, Apodemus sylvaticus, Myodes glareolus, Microtus arvalis, Microtus subterraneus and Micromys minutus) were examined for the presence of SFG rickettsiae and Coxiella burnetii by molecular methods. Suburban, natural and rural habitats were monitored to acquire information on the role of ticks and rodents in the agents' maintenance in various habitat types of Slovakia. The overall prevalence of rickettsial infection in questing I. ricinus and D. marginatus was 6.6% and 21.4%, respectively. Rickettsia helvetica, R. monacensis and non-identified rickettsial species were detected in I. ricinus, whereas R. slovaca and R. raoultii were identified in D. marginatus. Rickettsia spp.-infected I. ricinus occurred during the whole tick questing period. Rickettsia helvetica dominated (80.5%) followed by R. monacensis (6.5%). The species were present in all studied habitats. Rickettsia slovaca (66.7%) and R. raoultii (33.3%) were identified in D. marginatus from the rural habitat. Apodemus flavicollis was the most infested rodent species with I. ricinus, but My. glareolus carried the highest proportion of Rickettsia-positive I. ricinus larvae. Only 0.5% of rodents (A. flavicollis) and 5.2% of engorged I. ricinus removed from My. glareolus, A. flavicollis and M. arvalis were R. helvetica- and R. monacensis-positive. Coxiella burnetii was not detected in any of the tested samples. We hypothesize that rodents could play a role as carriers of infected ticks and contribute to the maintenance of rickettsial pathogens in natural foci. Long-term presence of SFG Rickettsia spp. was confirmed in questing ticks from different habitat

Unique Strain of Rickettsia parkeri Associated with the Hard Tick Dermacentor parumapertus Neumann in the Western United States.

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Paddock, Christopher D; Allerdice, Michelle E J; Karpathy, Sandor E; Nicholson, William L; Levin, Michael L; Smith, Travis C; Becker, Tom; Delph, Robert J; Knight, Robert N; Ritter, Jana M; Sanders, Jeanine H; Goddard, Jerome

2017-05-01

In 1953, investigators at the Rocky Mountain Laboratories in Hamilton, MT, described the isolation of a spotted fever group Rickettsia (SFGR) species from Dermacentor parumapertus ticks collected from black-tailed jackrabbits ( Lepus californicus ) in northern Nevada. Several decades later, investigators characterized this SFGR (designated the parumapertus agent) by using mouse serotyping methods and determined that it represented a distinct rickettsial serotype closely related to Rickettsia parkeri ; nonetheless, the parumapertus agent was not further characterized or studied. To our knowledge, no isolates of the parumapertus agent remain in any rickettsial culture collection, which precludes contemporary phylogenetic placement of this enigmatic SFGR. To rediscover the parumapertus agent, adult-stage D. parumapertus ticks were collected from black-tailed jackrabbits shot or encountered as roadkills in Arizona, Utah, or Texas from 2011 to 2016. A total of 339 ticks were collected and evaluated for infection with Rickettsia species. Of 112 D. parumapertus ticks collected in south Texas, 16 (14.3%) contained partial ompA sequences with the closest identity (99.6%) to Rickettsia sp. strain Atlantic rainforest Aa46, an SFGR that is closely related or identical to an SFGR species that causes a mild rickettsiosis in several states of Brazil. A pure isolate, designated strain Black Gap, was cultivated in Vero E6 cells, and sequence analysis of the rrs , gltA , sca0 , sca5 , and sca4 genes also revealed the closest genetic identity to Rickettsia sp. Atlantic rainforest Aa46. Phylogenetic analysis of the five concatenated rickettsial genes place Rickettsia sp. strain Black Gap and Rickettsia sp. Atlantic rainforest Aa46 with R. parkeri in a distinct and well-supported clade. IMPORTANCE We suggest that Rickettsia sp. Black Gap and Rickettsia sp. Atlantic rainforest Aa46 represent nearly identical strains of R. parkeri and that Rickettsia sp. Black Gap or a very similar

Seroprevalence against Rickettsia and Borrelia Species in Patients with Uveitis: A Prospective Survey

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Kim B. Madsen

2017-01-01

Full Text Available Vector-borne diseases such as Lyme borreliosis and rickettsioses have been associated with ocular inflammation. Our aim was to study patients with diagnosed uveitis to evaluate serological signs of infection or exposure to these tick-borne agents. Forty-eight patients were prospectively examined with serology together with medical records and a questionnaire concerning previous exposure, diseases, and treatments. Seven patients (14.6% showed seroconversion to Rickettsia spp. between acute and convalescent phase sera, which provides support for a positive Rickettsia diagnosis according to guidelines. The specificity was confirmed by Western blot. Additional 28 patients had stationary titres of which eight (16.6% had 1 : 256 or higher titre in the first serum, and another 13 patients were seronegative. No epidemiological risk factor or marker could be identified. For Borrelia, only three patients showed moderate IgG titres. A control group of 100 blood donors, 60 patients with rheumatic disease, and 56 patients seeking medical care were tested of which 2.0–7.1% showed low anti-Rickettsia titres and 3.0–8.3% anti-Borrelia titres. The findings are indicative for an association between infection or exposure to Rickettsia spp. and uveitis with a seropositivity among patients with recurrent uveitis in concordance with the spread of rickettsial exposure in a tick-exposed population.

Seroprevalence against Rickettsia and Borrelia Species in Patients with Uveitis: A Prospective Survey

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Madsen, Kim B.; Wallménius, Katarina; Fridman, Åke; Påhlson, Carl

2017-01-01

Vector-borne diseases such as Lyme borreliosis and rickettsioses have been associated with ocular inflammation. Our aim was to study patients with diagnosed uveitis to evaluate serological signs of infection or exposure to these tick-borne agents. Forty-eight patients were prospectively examined with serology together with medical records and a questionnaire concerning previous exposure, diseases, and treatments. Seven patients (14.6%) showed seroconversion to Rickettsia spp. between acute and convalescent phase sera, which provides support for a positive Rickettsia diagnosis according to guidelines. The specificity was confirmed by Western blot. Additional 28 patients had stationary titres of which eight (16.6%) had 1 : 256 or higher titre in the first serum, and another 13 patients were seronegative. No epidemiological risk factor or marker could be identified. For Borrelia, only three patients showed moderate IgG titres. A control group of 100 blood donors, 60 patients with rheumatic disease, and 56 patients seeking medical care were tested of which 2.0–7.1% showed low anti-Rickettsia titres and 3.0–8.3% anti-Borrelia titres. The findings are indicative for an association between infection or exposure to Rickettsia spp. and uveitis with a seropositivity among patients with recurrent uveitis in concordance with the spread of rickettsial exposure in a tick-exposed population. PMID:29318041

Detection of Rickettsia aeschlimannii and Rickettsia africae in ixodid ticks from Burkina Faso and Somali Region of Ethiopia by new real-time PCR assays.

Science.gov (United States)

Tomassone, L; De Meneghi, D; Adakal, H; Rodighiero, P; Pressi, G; Grego, E

2016-10-01

In the framework of cooperation for development projects in Burkina Faso and Ethiopia, we collected ixodid ticks from cattle, small ruminants and camels. We optimized new TaqMan Probe real-time PCR assays to detect Rickettsia aeschlimannii and Rickettsia africae OmpA gene in the collected samples. Rickettsia africae was identified in 75.0% Amblyomma variegatum (95%CI: 56.6-88.5), while R. aeschlimannii in 24.0% Hyalomma truncatum (95%CI: 9.4-45.1) and 50.0% H. rufipes (95%CI: 29.9-70.0) collected from cattle in different provinces throughout Burkina Faso. Ticks from the Libaan zone, Somali Region of Ethiopia, were also infected by R. africae (28.5% prevalence in Amblyomma gemma, 95%CI: 14.7-46.0) and R. aeschlimannii (27.0% H. truncatum, 95%CI: 5.0-62.9; 88.3% H. rufipes, 95%CI: 60.5-99.3). All tested ticks were adults. The developed diagnostic tools were highly sensitive and enabled us to rapidly classify R. aeschlimannii and R. africae, which were identified in Burkina Faso and in the Somali Region of Ethiopia for the first time. Further studies are needed to assess the zoonotic risk and prevalence of infection in local human populations, who have high contact rates with ticks and their animal hosts. Copyright © 2016 Elsevier GmbH. All rights reserved.

Rickettsia typhi in rodents and R. felis in fleas in Yucatán as a possible causal agent of undefined febrile cases.

Science.gov (United States)

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 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.

Molecular Detection and Identification of Rickettsia Species in Ticks (Acari: Ixodidae) Collected From Belize, Central America.

Science.gov (United States)

Polsomboon, Suppaluck; Hoel, David F; Murphy, Jittawadee R; Linton, Yvonne-Marie; Motoki, Maysa; Robbins, Richard G; Bautista, Kim; Bricen O, Ireneo; Achee, Nicole L; Grieco, John P; Ching, Wei-Mei; Chao, Chien-Chung

2017-11-07

Little is known about tick-borne rickettsial pathogens in Belize, Central America. We tested ixodid ticks for the presence of Rickettsia species in three of the six northern and western Belizean districts. Ticks were collected from domestic animals and tick drags over vegetation in 23 different villages in November 2014, February 2015, and May 2015. A total of 2,506 collected ticks were identified to the following species: Dermacentor nitens Neumann (46.69%), Rhipicephalus sanguineus (Latreille) (19.55%), Rhipicephalus microplus (Canestrini) (19.47%), Amblyomma cajennense complex (9.74%), Amblyomma maculatum Koch (3.47%), Amblyomma ovale Koch (0.68%), Ixodes nr affinis (0.16%), Amblyomma nr maculatum (0.12%), and Amblyomma nr oblongoguttatum (0.12%). Ticks were pooled according to species, life stage (larva, nymph, or adult), and location (n = 509) for DNA extraction and screened for genus Rickettsia by quantitative real-time polymerase chain reaction (qPCR). All 42 positive pools were found to be positive for spotted fever group (SFG) Rickettsia in pools of A. cajennense complex (n = 33), A. maculatum (n = 4), A. nr maculatum (n = 1), A. ovale (n = 1), R. sanguineus (n = 1), and I. nr affinis (n = 2). Rickettsia amblyommatis was identified from A. cajennense complex and A. nr maculatum. Rickettsia parkeri was found in A. maculatum, and Rickettsia sp. endosymbiont was detected in I. nr affinis. The presence of infected ticks suggests a risk of tick-borne rickettsioses to humans and animals in Belize. This knowledge can contribute to an effective tick management and disease control program benefiting residents and travelers. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Direct evidence of Rickettsia typhi infection in Rhipicephalus ...

African Journals Online (AJOL)

These studies remarks that in addition to rats, other animals like cats, opossums and dogs could be implied in the transmission of Rickettsia typhi as infected fleas obtained from serologically positive animals have been detected in samples from endemic areas. In Mexico, the higher number of murine typhus cases have ...

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

Directory of Open Access Journals (Sweden)

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.

Neorickettsia risticii, Rickettsia sp. and Bartonella sp. in Tadarida brasiliensis bats from Buenos Aires, Argentina.

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Cicuttin, Gabriel L; De Salvo, María N; La Rosa, Isabel; Dohmen, Federico E Gury

2017-06-01

Bats are potential reservoirs of many vector-borne bacterial pathogens. The aim of the present study was to detect species of Anaplasma, Ehrlichia, Neorickettsia, Rickettsia, Borrelia and Bartonella in Brazilian free-tailed bats (Tadarida brasiliensis, Molossidae) from Buenos Aires city, Argentina. Between 2012 and 2013, 61 T. brasiliensis from urban areas of Buenos Aires city were studied. The samples were molecularly screened by PCR and sequencing. Five bats (8.2%) were positive to Neorickettsia risticii, one (1.6%) was positive to Rickettsia sp. and three bats (4.9%) to Bartonella sp. For molecular characterization, the positive samples were subjected to amplification and sequencing of a fragment of p51 gene for N. risticii, a fragment of citrate synthase gene (gltA) for Rickettsia genus and a fragment of gltA for Bartonella genus. Phylogenetic tree was constructed using the maximum-likelihood method. Phylogenetic analysis of N. risticii detect in our study revealed that it relates to findings in the USA West Coast; Rickettsia sp. detected is phylogenetically within R. bellii group, which also includes many other Rickettsia endosymbionts of insects; and Bartonella sp. found is related to various Bartonella spp. described in Vespertilionidae bats, which are phylogenetically related to Molossidae. Our results are in accordance to previous findings, which demonstrate that insectivorous bats could be infected with vector-borne bacteria representing a potential risk to public health. Future research is necessary to clarify the circulation of these pathogens in bats from Buenos Aires. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimated seroprevalence of Anaplasma spp. and spotted fever group Rickettsia exposure among herders and livestock in Mongolia.

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von Fricken, Michael E; Lkhagvatseren, Sukhbaatar; Boldbaatar, Bazartseren; Nymadawa, Pagbajab; Weppelmann, Thomas A; Baigalmaa, Bekh-Ochir; Anderson, Benjamin D; Reller, Megan E; Lantos, Paul M; Gray, Gregory C

2018-01-01

To better understand the epidemiology of tick-borne disease in Mongolia, a comprehensive seroprevalence study was conducted investigating exposure to Anaplasma spp. and spotted fever group (SFG) Rickettsia spp. in nomadic herders and their livestock across three provinces from 2014 to 2015. Blood was collected from 397 herders and 2370 livestock, including sheep, goats, cattle, horses and camels. Antibodies against Anaplasma spp. and SFG Rickettsia were determined by indirect immunofluorescence using commercially available slides coated with Anaplasma phagocytophilum and Rickettsia rickettsii antigens. Logistic regression was used to determine if the odds of previous exposure differed by gender, location, and species, with or without adjustment for age. To examine the association between seroprevalence and environmental variables we used ArcGIS to circumscribe the five major clusters where human and animal data were collected. Anaplasma spp. exposure was detected in 37.3% (136/365) of humans and 47.3% (1120/2370) of livestock; SFG Rickettsia exposure was detected in 19.5% (73/374) humans and 20.4% (478/2342) livestock. Compared to the southern province (aimag) of Dornogovi, located in the Gobi Desert, humans were significantly more likely to be exposed to Anaplasma spp. and SFG Rickettsia in the northern provinces of Tov (OR=7.3, 95% CI: 3.5, 15.1; OR=3.3, 95% CI: 1.7, 7.5), and Selenge (OR=6.9, 95% CI: 3.4, 14.0; OR=2.2, 95% CI: 1.1, 4.8). The high seroprevalence of Anaplasma spp. and SFG Rickettsia in humans and livestock suggests that exposure to tick-borne pathogens may be common in herders and livestock in Mongolia, particularly in the more northern regions of the country. Until more is known about these pathogens in Mongolia, physicians and veterinarians in the countryside should consider testing for Anaplasma and SFG Rickettsia infections and treating clinically compatible cases, while public health authorities should expand surveillance efforts for these

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

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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

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

Science.gov (United States)

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.

Development of a Rickettsia bellii-Specific TaqMan Assay Targeting the Citrate Synthase Gene.

Science.gov (United States)

Hecht, Joy A; Allerdice, Michelle E J; Krawczak, Felipe S; Labruna, Marcelo B; Paddock, Christopher D; Karpathy, Sandor E

2016-11-01

Rickettsia bellii is a rickettsial species of unknown pathogenicity that infects argasid and ixodid ticks throughout the Americas. Many molecular assays used to detect spotted fever group (SFG) Rickettsia species do not detect R. bellii, so that infection with this bacterium may be concealed in tick populations when assays are used that screen specifically for SFG rickettsiae. We describe the development and validation of a R. bellii-specific, quantitative, real-time PCR TaqMan assay that targets a segment of the citrate synthase (gltA) gene. The specificity of this assay was validated against a panel of DNA samples that included 26 species of Rickettsia, Orientia, Ehrlichia, Anaplasma, and Bartonella, five samples of tick and human DNA, and DNA from 20 isolates of R. bellii, including 11 from North America and nine from South America. A R. bellii control plasmid was constructed, and serial dilutions of the plasmid were used to determine the limit of detection of the assay to be one copy per 4 µl of template DNA. This assay can be used to better determine the role of R. bellii in the epidemiology of tick-borne rickettsioses in the Western Hemisphere. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

Implication of the Bacterial Endosymbiont Rickettsia spp. in Interactions of the Whitefly Bemisia tabaci with Tomato yellow leaf curl virus

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Kliot, Adi; Cilia, Michelle; Czosnek, Henryk

2014-01-01

ABSTRACT Numerous animal and plant viruses are transmitted by arthropod vectors in a persistent, circulative manner. Tomato yellow leaf curl virus (TYLCV) is transmitted by the sweet potato whitefly Bemisia tabaci. We report here that infection with Rickettsia spp., a facultative endosymbiont of whiteflies, altered TYLCV-B. tabaci interactions. A B. tabaci strain infected with Rickettsia acquired more TYLCV from infected plants, retained the virus longer, and exhibited nearly double the transmission efficiency compared to an uninfected B. tabaci strain with the same genetic background. Temporal and spatial antagonistic relationships were discovered between Rickettsia and TYLCV within the whitefly. In different time course experiments, the levels of virus and Rickettsia within the insect were inversely correlated. Fluorescence in situ hybridization analysis of Rickettsia-infected midguts provided evidence for niche exclusion between Rickettsia and TYLCV. In particular, high levels of the bacterium in the midgut resulted in higher virus concentrations in the filter chamber, a favored site for virus translocation along the transmission pathway, whereas low levels of Rickettsia in the midgut resulted in an even distribution of the virus. Taken together, these results indicate that Rickettsia, by infecting the midgut, increases TYLCV transmission efficacy, adding further insights into the complex association between persistent plant viruses, their insect vectors, and microorganism tenants that reside within these insects. IMPORTANCE Interest in bacterial endosymbionts in arthropods and many aspects of their host biology in agricultural and human health systems has been increasing. A recent and relevant studied example is the influence of Wolbachia on dengue virus transmission by mosquitoes. In parallel with our recently studied whitefly-Rickettsia-TYLCV system, other studies have shown that dengue virus levels in the mosquito vector are inversely correlated with

Infection of the Gulf Coast Tick, Amblyomma Maculatum (Acari: Ixodidae), with Rickettsia Parkeri: First Report from the State of Delaware

Science.gov (United States)

2013-03-31

0279276E-D761-4A27-BFF7-7329E05E0F66 Infection of the Gulf Coast tick, Amblyomma maculatum (Acari: Ixodidae), with Rickettsia parkeri: first report from...Spring, MD 20910-1230, U.S.A. Abstract The molecular detection of Rickettsia parkeri in a Gulf Coast tick, Amblyomma maculatum, collected in Delaware...near Smyrna, Delaware. All specimens were tested for the presence of Rickettsia with a genus-specific quantitative real-time polymerase chain

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

NARCIS (Netherlands)

Laudisoit, A.; Falay, D.; Amundala, N.; de Bellock, J.G.; van Houtte, N.; Breno, M.; Verheven, E.; Wilschut, Liesbeth; Parola, P.; Raoult, D.; C., Socolovschi

2014-01-01

The prevalence and identity of Rickettsia and Bartonella in urban rat and flea populations were evaluated in Kisangani, Democratic Republic of the Congo (DRC) by molecular tools. An overall prevalence of 17% Bartonella species and 13% Rickettsia typhi, the agent of murine typhus, was found in the

Lipofuscinose ceróide neuronal: relato de quatro casos com estudo por histoquímica retal, microscopia eletrônica de conjuntiva e necrópsia

Directory of Open Access Journals (Sweden)

Luiz Fernando Bleggi Torres

1994-03-01

Full Text Available Os autores relatam os achados neuropatológicos e clínicos de quatro casos de lipofuscinose ceróide ou doença de Batten. Dois casos foram estudados por necrópsia: o encéfalo mostrou atrofia e neurônios contendo pigmento citoplasmático com características tintoriais de lipofuscina. Um caso foi diagnosticado por estudo histoquímico de biópsia retal, em material congelado em nitrogênio líquido demonstrando-se células ganglionares mioentéricas contendo acúmulo citoplasmático de material granular fosfatase ácida positivo, bem como em grande número de macrófagos do córion. O quarto caso foi diagnosticado por microscopia eletrônica de biópsia de conjuntiva, com identificação de inclusões curvelíneas membranáceas e tipo impressão digital.

Outbreaks of Rickettsia felis in Kenya and Senegal, 2010

Centers for Disease Control (CDC) Podcasts

This podcast describes the outbreak of Rickettsia felis in Kenya between August 2006 and June 2008, and in rural Senegal from November 2008 through July 2009. CDC infectious disease pathologist Dr. Chris Paddock discusses what researchers learned about this flea-borne disease and how to prevent infection.

Detection of Rickettsia felis in Wild Mammals from Three Municipalities in Yucatan, Mexico.

Science.gov (United States)

Panti-May, Jesús Alonso; Torres-Castro, Marco; Hernández-Betancourt, Silvia; Dzul-Rosado, Karla; Zavala-Castro, Jorge; López-Avila, Karina; Tello-Martín, Raúl

2015-09-01

The aim of this study was to provide information of the occurrence of Rickettsia felis in wild mammals from three municipalities in Yucatan, Mexico. The reactivity of rodent serum to Rickettsia antigens was detected in 80.9% (17 of 21) samples using immunofluorescence assay. Polymerase chain reaction identified rickettsial DNA in spleens of 43.5% (10 of 23) rodents and 57.1% (4 of 7) opossums. The identification of the rickettsial DNA was confirmed as R. felis by restriction fragment length polymorphism and DNA sequencing. This study comprises the first report of R. felis detection in wild mammals in Yucatan.

"Rickettsia amblyommii" induces cross protection against lethal Rocky Mountain spotted fever in a guinea pig model.

Science.gov (United States)

Blanton, Lucas S; Mendell, Nicole L; Walker, David H; Bouyer, Donald H

2014-08-01

Rocky Mountain spotted fever (RMSF) is a severe illness caused by Rickettsia rickettsii for which there is no available vaccine. We hypothesize that exposure to the highly prevalent, relatively nonpathogenic "Rickettsia amblyommii" protects against R. rickettsii challenge. To test this hypothesis, guinea pigs were inoculated with "R. amblyommii." After inoculation, the animals showed no signs of illness. When later challenged with lethal doses of R. rickettsii, those previously exposed to "R. amblyommii" remained well, whereas unimmunized controls developed severe illness and died. We conclude that "R. amblyommii" induces an immune response that protects from illness and death in the guinea pig model of RMSF. These results provide a basis for exploring the use of low-virulence rickettsiae as a platform to develop live attenuated vaccine candidates to prevent severe rickettsioses.

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

Science.gov (United States)

Ogrzewalska, Maria; Literák, Ivan; Capek, Miroslav; Sychra, Oldřich; Calderón, Víctor Álvarez; Rodríguez, Bernardo Calvo; Prudencio, Carlos; Martins, Thiago F; Labruna, Marcelo B

2015-06-01

The aim of this study was to document the presence of Rickettsia spp. in ticks parasitizing wild birds in Costa Rica. Birds were trapped at seven locations in Costa Rica during 2004, 2009, and 2010; then visually examined for the presence of ticks. Ticks were identified, and part of them was tested individually for the presence of Rickettsia spp. by polymerase chain reaction (PCR) using primers targeting fragments of the rickettsial genes gltA and ompA. PCR products were DNA-sequenced and analyzed in BLAST to determine similarities with previously reported rickettsial agents. A total of 1878 birds were examined, from which 163 birds (9%) were infested with 388 ticks of the genera Amblyomma and Ixodes. The following Amblyomma (in decreasing order of abundance) were found in immature stages (larvae and nymphs): Amblyomma longirostre, Amblyomma calcaratum, Amblyomma coelebs, Amblyomma sabanerae, Amblyomma varium, Amblyomma maculatum, and Amblyomma ovale. Ixodes ticks were represented by Ixodes minor and two unclassified species, designated here as Ixodes sp. genotype I, and Ixodes sp. genotype II. Twelve of 24 tested A. longirostre ticks were found to be infected with 'Candidatus Rickettsia amblyommii', and 2 of 4 A. sabanerae were found to be infected with Rickettsia bellii. Eight of 10 larval Ixodes minor were infected with an endosymbiont (a novel Rickettsia sp. agent) genetically related to the Ixodes scapularis endosymbiont. No rickettsial DNA was found in A. calcaratum, A. coelebs, A. maculatum, A. ovale, A. varium, Ixodes sp. I, and Ixodes sp. II. We report the occurrence of I. minor in Costa Rica for the first time and a number of new bird host-tick associations. Moreover, 'Candidatus R. amblyommii' and R. bellii were found in A. longirostre and A. sabanerae, respectively, in Costa Rica for the first time. Copyright © 2015 Elsevier GmbH. All rights reserved.

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

Directory of Open Access Journals (Sweden)

John Stephen Dumler

2011-10-01

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

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

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Audic Stéphane

2009-04-01

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

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

DEFF Research Database (Denmark)

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...

Multi-omics Analysis Sheds Light on the Evolution and the Intracellular Lifestyle Strategies of Spotted Fever Group Rickettsia spp.

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El Karkouri, Khalid; Kowalczewska, Malgorzata; Armstrong, Nicholas; Azza, Said; Fournier, Pierre-Edouard; Raoult, Didier

2017-01-01

Arthropod-borne Rickettsia species are obligate intracellular bacteria which are pathogenic for humans. Within this genus, Rickettsia slovaca and Rickettsia conorii cause frequent and potentially severe infections, whereas Rickettsia raoultii and Rickettsia massiliae cause rare and milder infections. All four species belong to spotted fever group (SFG) rickettsiae. However, R. slovaca and R. raoultii cause scalp eschar and neck lymphadenopathy (SENLAT) and are mainly associated with Dermacentor ticks, whereas the other two species cause Mediterranean spotted fever (MSF) and are mainly transmitted by Rhipicephalus ticks. To identify the potential genes and protein profiles and to understand the evolutionary processes that could, comprehensively, relate to the differences in virulence and pathogenicity observed between these four species, we compared their genomes and proteomes. The virulent and milder agents displayed divergent phylogenomic evolution in two major clades, whereas either SENLAT or MSF disease suggests a discrete convergent evolution of one virulent and one milder agent, despite their distant genetic relatedness. Moreover, the two virulent species underwent strong reductive genomic evolution and protein structural variations, as well as a probable loss of plasmid(s), compared to the two milder species. However, an abundance of mobilome genes was observed only in the less pathogenic species. After infecting Xenopus laevis cells, the virulent agents displayed less up-regulated than down-regulated proteins, as well as less number of identified core proteins. Furthermore, their similar and distinct protein profiles did not contain some genes (e.g., omp A/B and rick A) known to be related to rickettsial adhesion, motility and/or virulence, but may include other putative virulence-, antivirulence-, and/or disease-related proteins. The identified evolutionary forces herein may have a strong impact on intracellular expressions and strategies in these

Multi-omics Analysis Sheds Light on the Evolution and the Intracellular Lifestyle Strategies of Spotted Fever Group Rickettsia spp.

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Khalid El Karkouri

2017-07-01

Full Text Available Arthropod-borne Rickettsia species are obligate intracellular bacteria which are pathogenic for humans. Within this genus, Rickettsia slovaca and Rickettsia conorii cause frequent and potentially severe infections, whereas Rickettsia raoultii and Rickettsia massiliae cause rare and milder infections. All four species belong to spotted fever group (SFG rickettsiae. However, R. slovaca and R. raoultii cause scalp eschar and neck lymphadenopathy (SENLAT and are mainly associated with Dermacentor ticks, whereas the other two species cause Mediterranean spotted fever (MSF and are mainly transmitted by Rhipicephalus ticks. To identify the potential genes and protein profiles and to understand the evolutionary processes that could, comprehensively, relate to the differences in virulence and pathogenicity observed between these four species, we compared their genomes and proteomes. The virulent and milder agents displayed divergent phylogenomic evolution in two major clades, whereas either SENLAT or MSF disease suggests a discrete convergent evolution of one virulent and one milder agent, despite their distant genetic relatedness. Moreover, the two virulent species underwent strong reductive genomic evolution and protein structural variations, as well as a probable loss of plasmid(s, compared to the two milder species. However, an abundance of mobilome genes was observed only in the less pathogenic species. After infecting Xenopus laevis cells, the virulent agents displayed less up-regulated than down-regulated proteins, as well as less number of identified core proteins. Furthermore, their similar and distinct protein profiles did not contain some genes (e.g., ompA/B and rickA known to be related to rickettsial adhesion, motility and/or virulence, but may include other putative virulence-, antivirulence-, and/or disease-related proteins. The identified evolutionary forces herein may have a strong impact on intracellular expressions and strategies in

Multi-omics Analysis Sheds Light on the Evolution and the Intracellular Lifestyle Strategies of Spotted Fever Group Rickettsia spp.

Science.gov (United States)

El Karkouri, Khalid; Kowalczewska, Malgorzata; Armstrong, Nicholas; Azza, Said; Fournier, Pierre-Edouard; Raoult, Didier

2017-01-01

Arthropod-borne Rickettsia species are obligate intracellular bacteria which are pathogenic for humans. Within this genus, Rickettsia slovaca and Rickettsia conorii cause frequent and potentially severe infections, whereas Rickettsia raoultii and Rickettsia massiliae cause rare and milder infections. All four species belong to spotted fever group (SFG) rickettsiae. However, R. slovaca and R. raoultii cause scalp eschar and neck lymphadenopathy (SENLAT) and are mainly associated with Dermacentor ticks, whereas the other two species cause Mediterranean spotted fever (MSF) and are mainly transmitted by Rhipicephalus ticks. To identify the potential genes and protein profiles and to understand the evolutionary processes that could, comprehensively, relate to the differences in virulence and pathogenicity observed between these four species, we compared their genomes and proteomes. The virulent and milder agents displayed divergent phylogenomic evolution in two major clades, whereas either SENLAT or MSF disease suggests a discrete convergent evolution of one virulent and one milder agent, despite their distant genetic relatedness. Moreover, the two virulent species underwent strong reductive genomic evolution and protein structural variations, as well as a probable loss of plasmid(s), compared to the two milder species. However, an abundance of mobilome genes was observed only in the less pathogenic species. After infecting Xenopus laevis cells, the virulent agents displayed less up-regulated than down-regulated proteins, as well as less number of identified core proteins. Furthermore, their similar and distinct protein profiles did not contain some genes (e.g., ompA/B and rickA) known to be related to rickettsial adhesion, motility and/or virulence, but may include other putative virulence-, antivirulence-, and/or disease-related proteins. The identified evolutionary forces herein may have a strong impact on intracellular expressions and strategies in these rickettsiae

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

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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.

Ganglio centinela en melanoma de cara: abordaje inicial

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Enrique Cadena Piñeros

2012-07-01

de la cara a quien se practicó resección local amplia del tumor y extracción de los centinelas marcados por linfogammagrafía y a la vez disección de los relevos ganglionares positivos para drenaje demostrados por este estudio de medicina nuclear.

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

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

2016-07-22

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.

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

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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.

Amblyomma imitator Ticks as Vectors of Rickettsia rickettsii, Mexico

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Oliveira, Karla A.; Pinter, Adriano; Medina-Sanchez, Aaron; Boppana, Venkata D.; Wikel, Stephen K.; Saito, Tais B.; Shelite, Thomas; Blanton, Lucas; Popov, Vsevolod; Teel, Pete D.; Walker, David H.; Galvao, Marcio A.M.; Mafra, Claudio

2010-01-01

Real-time PCR of Amblyomma imitator tick egg masses obtained in Nuevo Leon State, Mexico, identified a Rickettsia species. Sequence analyses of 17-kD common antigen and outer membrane protein A and B gene fragments showed to it to be R. rickettsii, which suggested a potential new vector for this bacterium. PMID:20678325

The natural infection of birds and ticks feeding on birds with Rickettsia spp. and Coxiella burnetii in Slovakia.

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Berthová, Lenka; Slobodník, Vladimír; Slobodník, Roman; Olekšák, Milan; Sekeyová, Zuzana; Svitálková, Zuzana; Kazimírová, Mária; Špitalská, Eva

2016-03-01

Ixodid ticks (Acari: Ixodidae) are known as primary vectors of many pathogens causing diseases in humans and animals. Ixodes ricinus is a common ectoparasite in Europe and birds are often hosts of subadult stages of the tick. From 2012 to 2013, 347 birds belonging to 43 species were caught and examined for ticks in three sites of Slovakia. Ticks and blood samples from birds were analysed individually for the presence of Rickettsia spp. and Coxiella burnetii by PCR-based methods. Only I. ricinus was found to infest birds. In total 594 specimens of bird-attached ticks were collected (451 larvae, 142 nymphs, 1 female). Altogether 37.2% (16/43) of bird species were infested by ticks and some birds carried more than one tick. The great tit, Parus major (83.8%, 31/37) was the most infested species. In total, 6.6 and 2.7% of bird-attached ticks were infected with Rickettsia spp. and C. burnetii, respectively. Rickettsia helvetica predominated (5.9%), whereas R. monacensis (0.5%) was only sporadically detected. Coxiella burnetii was detected in 0.9%, Rickettsia spp. in 8.9% and R. helvetica in 4.2% of bird blood samples. The great tit was the bird species most infested with I. ricinus, carried R. helvetica and C. burnetti positive tick larvae and nymphs and was found to be rickettsaemic in its blood. Further studies are necessary to define the role of birds in the circulation of rickettsiae and C. burnetii in natural foci.

Life inside a gall: closeness does not favour horizontal transmission of Rickettsia between a gall wasp and its parasitoid.

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Gualtieri, Liberata; Nugnes, Francesco; Nappo, Anna G; Gebiola, Marco; Bernardo, Umberto

2017-07-01

The incidence of horizontal transmission as a route for spreading symbiont infections is still being debated, but a common view is that horizontal transfers require intimate between-species relationships. Here we study a system that meets ideal requirements for horizontal transmission: the gall wasp Leptocybe invasa and its parasitoid Quadrastichus mendeli (Hymenoptera: Eulophidae). These wasps belong to the same subfamily, spend most of their lives inside the same minute gall and are both infected by Rickettsia, a maternally inherited endosymbiotic bacteria that infects several arthropods, sometimes manipulating their reproduction, like inducing thelytokous parthenogenesis in L. invasa. Despite intimate contact, close phylogenetic relationship and the parasitoid's host specificity, we show that host and parasitoid do not share the same Rickettsia. We provide indirect evidence that Rickettsia infecting Q. mendeli may be inducing thelytokous parthenogenesis, as the symbiont is densely present in the reproductive apparatus and is vertically transmitted. Phylogenetic analyses based on 16S and gltA placed this symbiont in the leech group. The confirmed and presumed parthenogenesis-inducing Rickettsia discovered so far only infect eulophid wasps, and belong to three different groups, suggesting multiple independent evolution of the parthenogenesis inducing phenotype. We also show some degree of cospeciation between Rickettsia and their eulophid hosts. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Coxiella burnetii and Rickettsia conorii: Two zoonotic pathogens in peridomestic rodents and their ectoparasites in Nigeria.

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Kamani, Joshua; Baneth, Gad; Gutiérrez, Ricardo; Nachum-Biala, Yaarit; Mumcuoglu, Kosta Y; Harrus, Shimon

2018-01-01

Rodents are hosts of numerous pathogenic agents of public health importance globally. Their ability to harbor these pathogens without showing overt clinical signs of disease has epidemiologic consequences. In some rural settings in Nigeria, humans and rodents do not only share feeds and abode, but the latter may end up on the table of the former as a source of protein, thereby increasing the risks of disease transmission. Molecular assays were used to detect and characterize two agents of zoonotic importance, Coxiella burnetii and Rickettsia spp. in 194 peridomestic rodents captured in a peri-urban setting in Nigeria, and 32 pools of ectoparasites removed from them, to determine their possible role in the epidemiology of these diseases in this country. Targeting and characterizing the insertion sequence IS1111, C. burnetii DNA was detected in 4 out of 194 (2.1%) rodents comprising 3 out of 121 (2.5%) Rattus norvegicus and 1 out of 48 (2.1%) Rattus rattus screened in this study. Rickettsia spp. DNA was detected in two Rhipicephalus sanginueus sensu lato pools (i.e. RT1 and RT4) using the citrate synthase (gltA) gene and further characterized by amplification and sequence analysis of six genes to determine their identity. The RT1 sample consistently gave 98-100% identity to Rickettsia conorii str. Malish 7 for the various genes and loci studied. However, the identity of RT4 could not be definitively determined due to variable identities to different Rickettsia spp. according to the gene or loci under consideration. Further isolation study to determine if the RT4 characterized is a new variant or a mixture of sequences of different rickettsiae within the pool will be worthwhile. Copyright © 2017 Elsevier GmbH. All rights reserved.

Molecular Detection of Rickettsia africae in Amblyomma variegatum Collected from Sudan.

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Nakao, Ryo; Qiu, Yongjin; Salim, Bashir; Hassan, Shawgi Mohamed; Sugimoto, Chihiro

2015-05-01

Despite the increasing awareness of the importance of emerging vector-borne diseases, human tick-borne diseases, particularly rickettsial infections, are overlooked, especially in the countries such as Sudan with limited resources to perform molecular-based surveys. This study aimed at detection and genetic characterization of Rickettsia spp. in ticks collected from Sudan. The samples were first screened for the presence of rickettsial agents by gltA real-time PCR and subsequently characterized by gltA and ompA PCR and size-based multispacer typing. The results demonstrated the wide distribution of Rickettsia africae and/or closely related species across Sudan. The results of this report highlight the need for careful consideration of rickettsial infections in patients with nonmalarial febrile illness in this country. Nationwide surveillance on ticks associated with human rickettsial infections in Sudan is warranted.

High detection rate of Rickettsia africae in Amblyomma variegatum but low prevalence of anti-rickettsial antibodies in healthy pregnant women in Madagascar.

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Keller, Christian; Krüger, Andreas; Schwarz, Norbert Georg; Rakotozandrindrainy, Raphael; Rakotondrainiarivelo, Jean Philibert; Razafindrabe, Tsiry; Derschum, Henri; Silaghi, Cornelia; Pothmann, Daniela; Veit, Alexandra; Hogan, Benedikt; May, Jürgen; Girmann, Mirko; Kramme, Stefanie; Fleischer, Bernhard; Poppert, Sven

2016-02-01

Tick-borne spotted fever group (SFG) rickettsioses are emerging infectious diseases in Sub-Saharan Africa. In Madagascar, the endemicity of tick-borne rickettsiae and their vectors has been incompletely studied. The first part of the present study was conducted in 2011 and 2012 to identify potential anthropophilic tick vectors for SFG rickettsiae on cattle from seven Malagasy regions, and to detect and characterize rickettsiae in these ticks. Amblyomma variegatum was the only anthropophilic tick species found on 262 cattle. Using a novel ompB-specific qPCR, screening for rickettsial DNA was performed on 111 A. variegatum ticks. Rickettsial DNA was detected in 96 of 111 ticks studied (86.5%). Rickettsia africae was identified as the only infecting rickettsia using phylogenetic analysis of ompA and ompB gene sequences and three variable intergenic spacers from 11 ticks. The second part of the study was a cross-sectional survey for antibodies against SFG rickettsiae in plasma samples taken from healthy, pregnant women at six locations in Madagascar, two at sea level and four between 450 and 1300m altitude. An indirect fluorescent antibody test with Rickettsia conorii as surrogate SFG rickettsial antigen was used. We found R. conorii-seropositives at all altitudes with prevalences between 0.5% and 3.1%. Our results suggest that A. variegatum ticks highly infected with R. africae are the most prevalent cattle-associated tick vectors for SFG rickettsiosis in Madagascar. Transmission of SFG rickettsiosis to humans occurs at different altitudes in Madagascar and should be considered as a relevant cause of febrile diseases. Copyright © 2015 Elsevier GmbH. All rights reserved.

Molecular detection of Rickettsia aeschlimannii in Hyalomma spp. ticks from camels (Camelus dromedarius) in Nigeria, West Africa.

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Kamani, J; Baneth, G; Apanaskevich, D A; Mumcuoglu, K Y; Harrus, S

2015-06-01

Several species of the spotted fever group rickettsiae have been identified as emerging pathogens throughout the world, including in Africa. In this study, 197 Hyalomma ticks (Ixodida: Ixodidae) collected from 51 camels (Camelus dromedarius) in Kano, northern Nigeria, were screened by amplification and sequencing of the citrate synthase (gltA), outer membrane protein A (ompA) and 17-kDa antigen gene fragments. Rickettsia sp. gltA fragments were detected in 43.3% (42/97) of the tick pools tested. Rickettsial ompA gene fragments (189 bp and 630 bp) were detected in 64.3% (n = 27) and 23.8% (n = 10) of the gltA-positive tick pools by real-time and conventional polymerase chain reaction (PCR), respectively. The amplicons were 99-100% identical to Rickettsia aeschlimannii TR/Orkun-H and R. aeschlimannii strain EgyRickHimp-El-Arish in GenBank. Furthermore, 17-kDa antigen gene fragments of 214 bp and 265 bp were detected in 59.5% (n = 25) and 38.1% (n = 16), respectively, of tick pools, and sequences were identical to one another and 99-100% identical to those of the R. aeschlimannii strain Ibadan A1 in GenBank. None of the Hyalomma impressum ticks collected were positive for Rickettsia sp. DNA. Rickettsia sp. gltA fragments (133 bp) were detected in 18.8% of camel blood samples, but all samples were negative for the other genes targeted. This is the first report to describe the molecular detection of R. aeschlimannii in Hyalomma spp. ticks from camels in Nigeria. © 2015 The Royal Entomological Society.

Spotted fever rickettsiae in wild-living rodents from south-western Poland.

NARCIS (Netherlands)

Gajda, Ewa; Hildebrand, Joanna; Sprong, Hein; Buńkowska-Gawlik, Katarzyna; Perec-Matysiak, Agnieszka; Coipan, Elena Claudia

2017-01-01

Rickettsiae are obligate intracellular alpha-proteobacteria. They are transmitted via arthropod vectors, which transmit the bacteria between animals and occasionally to humans. So far, much research has been conducted to indicate reservoir hosts for these microorganisms, but our knowledge is still

First detection of Candidatus Rickettsia barbariae in the flea Vermipsylla alakurt from north-western China.

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Zhao, Shan-Shan; Li, Hong-Yu; Yin, Xiao-Ping; Liu, Zhi-Qiang; Chen, Chuang-Fu; Wang, Yuan-Zhi

2016-06-07

Vermipsylla is a genus of the family Vermipsyllidae within the order Siphonaptera of fleas. Vermipsylla alakurt is mainly distributed in alpine pastoral areas of Kazakhstan, Mongolia, China and Nepal, and infests sheep, yaks and horses, causing irritation, poor condition, anaemia and even death. However, to date, no rickettsial agents have been reported in V. alakurt. A total of 133 fleas were collected directly from the tails of three sheep flocks (n = 335) in Minfeng County, Xinjiang Uygur Autonomous Region, north-western China. Of these, 55 fleas were identified by morphological examination and molecular analysis of four loci (the ribosomal 18S and 28S rDNA genes and the mitochondrial genes cytochrome  c oxidase subunit II and elongation factor 1-alpha). Eight Rickettsia-specific gene fragments originated from seven genes: the 17-kilodalton antigen gene (17-kDa), citrate synthase gene (gltA), 16S rRNA gene (rrs), outer membrane protein A gene (ompA), surface cell antigen 1 gene (sca1), PS120 protein gene (gene D), and outer membrane protein B gene (ompB, two fragments), were used to identify the species of Rickettsia in 53 fleas. The amplified products were sequenced and included in a phylogenetic analysis to verify the taxonomic identification of the rickettsial agents. Based on morphological and molecular evidence, the flea was identified as Vermipsylla alakurt. Nine samples were positive (16.98 %, 9/53) for Rickettsia spp. The phylogenetic tree revealed that the rickettsial agents found in V. alakurt cluster with Candidatus Rickettsia barbariae. Our study suggests that: (i) V. alakurt may serve as a carrier for Candidatus R. barbariae; and (ii) Candidatus R. barbariae, previously reported in Israel, is the eighth newly discovered validated Rickettsia species in China. This finding extends our knowledge of the distribution of Candidatus R. barbariae and the profile of carriers, which not only comprise ticks but also fleas.

Rickettsia (Rickettsiales: Rickettsiaceae) Vector Biodiversity in High Altitude Atlantic Forest Fragments Within a Semiarid Climate: A New Endemic Area of Spotted-Fever in Brazil.

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Moerbeck, Leonardo; Vizzoni, Vinícius F; Machado-Ferreira, Erik; Cavalcante, Robson C; Oliveira, Stefan V; Soares, Carlos A G; Amorim, Marinete; Gazêta, Gilberto S

2016-11-01

Rickettsioses are re-emerging vector-borne zoonoses with a global distribution. Recently, Rickettsia sp. strain Atlantic rainforest has been associated with new human spotted-fever (SF) cases in Brazil, featuring particular clinical signs: eschar formation and lymphadenopathy. These cases have been associated with the tick species, Amblyomma ovale From 2010 until 2015, the Brazilian Health Department confirmed 11 human SF cases in the Maciço de Baturité region, Ceará, Brazil. The present study reports the circulation of Rickettsia spp. in vectors from this entirely new endemic area for SF. A total of 1,727 ectoparasites were collected in this area from the environment, humans, and wild and domestic animals. Samples (n = 887) were screened by polymerase chain reaction (PCR), targeting the gltA and ompA rickettsial genes. Sequencing and phylogenetic analyses of gltA gene amplicons were carried out for 13 samples positive for both screening PCRs. Fragments of gltA and ompA from three samples were cloned, sequenced, and analyzed further. A. ovale and Rhipicephalus sanguineus specimens, collected from dogs, were found to be infected with Rickettsia sp. str. Atlantic rainforest, suggesting the importance of dogs in the epidemic cycle. Candidatus Rickettsia andeanae, Rickettsia felis, and Rickettsia bellii were also found infecting ticks and fleas in five municipalities, demonstrating the broad diversity of rickettsiae in circulation in the studied area. This study reports, for the first time, evidence of infection with Rickettsia sp. strain Atlantic rainforest in A. ovale and R. sanguineus in Ceará, and Ca. R. andeanae in an Atlantic rainforest environment of Brazil. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The Phylogeny of Rickettsia Using Different Evolutionary Signatures: How Tree-Like is Bacterial Evolution?

Science.gov (United States)

Murray, Gemma G. R.; Weinert, Lucy A.; Rhule, Emma L.; Welch, John J.

2016-01-01

Rickettsia is a genus of intracellular bacteria whose hosts and transmission strategies are both impressively diverse, and this is reflected in a highly dynamic genome. Some previous studies have described the evolutionary history of Rickettsia as non-tree-like, due to incongruity between phylogenetic reconstructions using different portions of the genome. Here, we reconstruct the Rickettsia phylogeny using whole-genome data, including two new genomes from previously unsampled host groups. We find that a single topology, which is supported by multiple sources of phylogenetic signal, well describes the evolutionary history of the core genome. We do observe extensive incongruence between individual gene trees, but analyses of simulations over a single topology and interspersed partitions of sites show that this is more plausibly attributed to systematic error than to horizontal gene transfer. Some conflicting placements also result from phylogenetic analyses of accessory genome content (i.e., gene presence/absence), but we argue that these are also due to systematic error, stemming from convergent genome reduction, which cannot be accommodated by existing phylogenetic methods. Our results show that, even within a single genus, tests for gene exchange based on phylogenetic incongruence may be susceptible to false positives. PMID:26559010

Frequency of antibodies class IgG anti-Rickettsia rickettsii in horses of Universidade Federal Rural do Rio de Janeiro, Seropédica campus

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Matheus Dias Cordeiro

2015-03-01

Full Text Available ABSTRACT. Cordeiro M.D., Raia V.A., Valim J.R.A., Castro G.N.S., Souza C.E. & Fonseca A.H. [Frequency of antibodies class IgG anti-Rickettsia rickettsii in horses of Universidade Federal Rural do Rio de Janeiro, Seropédica campus.] Frequência de anticorpos da classe IgG anti-Rickettsia rickettsii em equinos na Universidade Federal Rural do Rio de Janeiro, Campus Seropédica. Revista Brasileira de Medicina Veterinária, 37(1:78-82, 2015. Departamento de Epidemiologia e Saúde Pública, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Campus Seropédica, BR 465, Km7, Seropédica, RJ 23890-000, Brasil. E-mail: adivaldo@ufrrj.br The aim of this study was to verify, through the indirect immunofluorescence assay (IFA, the frequency of anti-Rickettsia rickettsii antibodies in horses at Universidade Federal Rural do Rio de Janeiro (UFRRJ Seropédica campus, state of Rio de Janeiro. We analyzed serum samples from 42 horses from Department of Breeding Equine of UFRRJ. All samples were tested using fixed slides with antigens for R. rickettsii, Rickettsia rhipicephali and Rickettsia parkeri. We observed an overall prevalence of Rickettsia spp. 83.33% (35/42. For the agent R. rickettsii revealed a prevalence of 66.67% (28/42, still being categorized in titers of 1:64 (19/28 and 1:128 (9/28. Nine of the 28 positives horses for R. rickettsii (21.43% were no reactive to other agents, with titers 1:64 (8/9 and 1:128 (1/9. The only tick species found parasitizing horses on the campus of UFRRJ during the collection period were Amblyomma cajennense and Dermacentor nitens. The UFRRJ presents an environment that provides a ideal epidemiological niche for the permanence of Rickettsia bacteria. The high prevalence found in this study indicates that attention to epidemiological agent of Brazilian Spotted Fever in the study area is of utmost importance. The aim of this study was to verify, through the indirect immunofluorescence assay (IFA, the

Validación de la punción aspiración con aguja fina (PAAF) en el diagnóstico de linfadenitis tuberculosa en pacientes con infección por el virus de la inmunodeficiencia humana (VIH)

OpenAIRE

Cabrera, Susana G; Ortega, Virginia; Medina, Julio C; Gualco, Gabriela; Viola, Marcelo; Pérez, Graciela; Musto, María L.; Zeballos, Justino; Savio, Eduardo

2009-01-01

Resumen Introducción: la punción aspiración aguja fina (PAAF) de ganglio linfático es una técnica sencilla, rápida y de bajo costo para la obtención de muestras para diagnóstico. Objetivo: el objetivo del estudio fue validar la PAAF en el diagnóstico de linfadenitis tuberculosa (TB) en pacientes infectados por el virus de la inmunodeficiencia humana (VIH), utilizando como "gold standard" el cultivo de Mycobacterium tuberculosis en biopsia ganglionar o la histopatología más la respuesta al tra...

The Effects of Beta Rays (Tritium) on the Growth of Rickettsiae and Influenza Virus; Effets du Rayonnement Beta (du Tritium) sur la Proliferation des Rickettsies et des Virus de la Grippe; 0414 0435 ; Influencia de los Rayos Beta (Tritio) sobre la Multiplicacion de Rickettsia y de Virus de la Gripe

Energy Technology Data Exchange (ETDEWEB)

Greiff, D. [Marquette University, School of Medicine, Milwaukee, WI (United States)

1962-02-15

vesiculaire) etait completement inhibee -dans les oeufs contenant de l'oxyde de tritium a raison de 180, 90 et 45 millicuries par oeuf et partiellement inhibee chez les groupes contenant 22,5 et 11,2 millicuries par oeuf. Des resultats analogues ont ete obtenus apres inoculation d'oxyde de tritium, a raison de 1 millicurie pour 10{sup 8} cellules, dans des cultures de cellules KB, disposees en couches isolees et infectees par R. mooseri ou R. akari. L'injection d'oxyde de tritium, avant l'infection par le virus, a eu pour effet de reduire la periode latente pour la liberation des virus de la grippe hors de la membrane chorio-allantoieque des oeufs -embryonnes. Deux heures apres l'inoculation de l'agent infectieux, le nombre des virus s'etait multiplie par mille dans les fluides chorio-allantoieques des oeufs traites. Lorsque des quantites -decelables de virus sont apparues dans les fluides chorio-allantoieques des oeufs temoins, huit heures apres l'infection, la DI{sub 50} des oeufs trities etait de 10{sup -5,6}; vingt-quatre heures apres l'infection, les deux series presentaient une DI{sub 50} de 10{sup -7,5}. Les quantites de virus dans les membranes des oeufs trities etaient egalement accrues. La liberation du virus a ete obtenue par les procedes suivants: enlevement et lavage des membranes, sechage des membranes par sublimation sous vide a basse temperature et rupture des cellules des membranes par rehydratation dans l'eau distillee. (author) [Spanish] La multiplicacion de Rickettsia mooseri (tifus de los roedores) aumenta' considerablemente en los huevos fecundados cuando estos contienen 180, 90 y 45 mcuries de oxido de tritio por huevo siendo el incremento ligero en los que contienen solamente 22,5 mcuries/huevo ; cuando solo se administran 11,2 mcuries/huevo, no se aprecia ningun aumento de la infeccion en comparacion con los testigos. La multiplicacion de Rickettsia akari (viruela rickettsial) quedo totalmente inhibida en los huevos que contenian 180, 90 y 45 mcuries

A Rickettsia Genome Overrun by Mobile Genetic Elements Provides Insight into the Acquisition of Genes Characteristic of an Obligate Intracellular Lifestyle

Science.gov (United States)

Joardar, Vinita; Williams, Kelly P.; Driscoll, Timothy; Hostetler, Jessica B.; Nordberg, Eric; Shukla, Maulik; Walenz, Brian; Hill, Catherine A.; Nene, Vishvanath M.; Azad, Abdu F.; Sobral, Bruno W.; Caler, Elisabet

2012-01-01

We present the draft genome for the Rickettsia endosymbiont of Ixodes scapularis (REIS), a symbiont of the deer tick vector of Lyme disease in North America. Among Rickettsia species (Alphaproteobacteria: Rickettsiales), REIS has the largest genome sequenced to date (>2 Mb) and contains 2,309 genes across the chromosome and four plasmids (pREIS1 to pREIS4). The most remarkable finding within the REIS genome is the extraordinary proliferation of mobile genetic elements (MGEs), which contributes to a limited synteny with other Rickettsia genomes. In particular, an integrative conjugative element named RAGE (for Rickettsiales amplified genetic element), previously identified in scrub typhus rickettsiae (Orientia tsutsugamushi) genomes, is present on both the REIS chromosome and plasmids. Unlike the pseudogene-laden RAGEs of O. tsutsugamushi, REIS encodes nine conserved RAGEs that include F-like type IV secretion systems similar to that of the tra genes encoded in the Rickettsia bellii and R. massiliae genomes. An unparalleled abundance of encoded transposases (>650) relative to genome size, together with the RAGEs and other MGEs, comprise ∼35% of the total genome, making REIS one of the most plastic and repetitive bacterial genomes sequenced to date. We present evidence that conserved rickettsial genes associated with an intracellular lifestyle were acquired via MGEs, especially the RAGE, through a continuum of genomic invasions. Robust phylogeny estimation suggests REIS is ancestral to the virulent spotted fever group of rickettsiae. As REIS is not known to invade vertebrate cells and has no known pathogenic effects on I. scapularis, its genome sequence provides insight on the origin of mechanisms of rickettsial pathogenicity. PMID:22056929

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

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Luciane Daniele Cardoso

2006-03-01

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

Isolation and characterization of the dnaA gene of Rickettsia prowazekii

International Nuclear Information System (INIS)

Waite, R.T.; Shaw, E.I.; Winkler, H.H.; Wood, D.G.

1998-01-01

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)

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

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Dora Amparo Estrada

2006-02-01

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

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

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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

Development and Validation of an Improved PCR Method Using the 23S-5S Intergenic Spacer for Detection of Rickettsiae in Dermacentor variabilis Ticks and Tissue Samples from Humans and Laboratory Animals

Science.gov (United States)

Kakumanu, Madhavi L.; Ponnusamy, Loganathan; Sutton, Haley T.; Meshnick, Steven R.; Nicholson, William L.

2016-01-01

A novel nested PCR assay was developed to detect Rickettsia spp. in ticks and tissue samples from humans and laboratory animals. Primers were designed for the nested run to amplify a variable region of the 23S-5S intergenic spacer (IGS) of Rickettsia spp. The newly designed primers were evaluated using genomic DNA from 11 Rickettsia species belonging to the spotted fever, typhus, and ancestral groups and, in parallel, compared to other Rickettsia-specific PCR targets (ompA, gltA, and the 17-kDa protein gene). The new 23S-5S IGS nested PCR assay amplified all 11 Rickettsia spp., but the assays employing other PCR targets did not. The novel nested assay was sensitive enough to detect one copy of a cloned 23S-5S IGS fragment from “Candidatus Rickettsia amblyommii.” Subsequently, the detection efficiency of the 23S-5S IGS nested assay was compared to those of the other three assays using genomic DNA extracted from 40 adult Dermacentor variabilis ticks. The nested 23S-5S IGS assay detected Rickettsia DNA in 45% of the ticks, while the amplification rates of the other three assays ranged between 5 and 20%. The novel PCR assay was validated using clinical samples from humans and laboratory animals that were known to be infected with pathogenic species of Rickettsia. The nested 23S-5S IGS PCR assay was coupled with reverse line blot hybridization with species-specific probes for high-throughput detection and simultaneous identification of the species of Rickettsia in the ticks. “Candidatus Rickettsia amblyommii,” R. montanensis, R. felis, and R. bellii were frequently identified species, along with some potentially novel Rickettsia strains that were closely related to R. bellii and R. conorii. PMID:26818674

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

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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.

Outbreaks of Rickettsia felis in Kenya and Senegal, 2010

Centers for Disease Control (CDC) Podcasts

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.

Detection of Rickettsia helvetica in Ixodes ricinus infesting wild and domestic animals and in a botfly larva (Cephenemyia stimulator) infesting roe deer in Germany.

Science.gov (United States)

Scheid, Patrick; Speck, Stephanie; Schwarzenberger, Rafael; Litzinger, Mark; Balczun, Carsten; Dobler, Gerhard

2016-10-01

Ixodes ricinus is a well-known vector of different human pathogens including Rickettsia helvetica. The role of wild mammals in the distribution and probable maintenance of Rickettsia in nature is still to be determined. We therefore investigated various parasites from different wild mammals as well as companion animals for the presence of Rickettsia. A total of 606 I. ricinus, 38 Cephenemyia stimulator (botfly larvae), one Dermacentor reticulatus, 24 Haematopinus suis (hog lice) and 30 Lipoptena cervi (deer flies) were collected from free-ranging animals during seasonal hunting, and from companion animals. Sample sites included hunting leases at three main sampling areas and five additional areas in West and Central Germany. All collected parasites were screened for Rickettsia spp. and I. ricinus were investigated for tick-borne encephalitis virus (TBEV) in addition. While no TBEV was detected, the minimum infection rate (MIR) of I. ricinus with Rickettsia was 4.1% referring to all sampling sites and up to 6.9% at the main sampling site in Koblenz area. Sequencing of a fragment of the ompB gene identified R. helvetica. Approximately one third (29.5%) of the animals carried Rickettsia-positive ticks and the MIR in ticks infesting wild mammals ranged from 4.1% (roe deer) to 9.5%. These data affirm the widespread distribution of R. helvetica in Germany. One botfly larva from roe deer also harboured R. helvetica. Botfly larvae are obligate parasites of the nasal cavity, pharynx and throat of cervids and feed on cell fragments and blood. Based on this one might hypothesise that R. helvetica likely induces rickettsemia in cervids thus possibly contributing to maintenance and distribution of this rickettsia in the field. Copyright © 2016 Elsevier GmbH. All rights reserved.

Investigating the Adult Ixodid Tick Populations and Their Associated Anaplasma, Ehrlichia, and Rickettsia Bacteria at a Rocky Mountain Spotted Fever Hotspot in Western Tennessee.

Science.gov (United States)

Trout Fryxell, Rebecca T; Hendricks, Brain M; Pompo, Kimberly; Mays, Sarah E; Paulsen, Dave J; Operario, Darwin J; Houston, Allan E

2017-08-01

Ehrlichiosis and rickettsiosis are two common bacterial tick-borne diseases in the southeastern United States. Ehrlichiosis is caused by ehrlichiae transmitted by Amblyomma americanum and rickettsiosis is caused by rickettsiae transmitted by Amblyomma maculatum and Dermacentor variabilis. These ticks are common and have overlapping distributions in the region. The objective of this study was to identify Anaplasma, Ehrlichia, and Rickettsia species associated with questing ticks in a Rocky Mountain spotted fever (RMSF) hotspot, and identify habitats, time periods, and collection methods for collecting questing-infected ticks. Using vegetation drags and CO 2 -baited traps, ticks were collected six times (May-September 2012) from 100 sites (upland deciduous, bottomland deciduous, grassland, and coniferous habitats) in western Tennessee. Adult collections were screened for Anaplasma and Ehrlichia (simultaneous polymerase chain reaction [PCR]) and Rickettsia using genus-specific PCRs, and resulting positive amplicons were sequenced. Anaplasma and Ehrlichia were only identified within A. americanum (Ehrlichia ewingii, Ehrlichia chaffeensis, Panola Mountain Ehrlichia, and Anaplasma odocoilei sp. nov.); more Ehrlichia-infected A. americanum were collected at the end of June regardless of habitat and collection method. Rickettsia was identified in three tick species; "Candidatus Rickettsia amblyommii" from A. americanum, R. parkeri and R. andeanae from A. maculatum, and R. montanensis ( = montana) from D. variabilis. Overall, significantly more Rickettsia-infected ticks were identified as A. americanum and A. maculatum compared to D. variabilis; more infected-ticks were collected from sites May-July and with dragging. In this study, we report in the Tennessee RMSF hotspot the following: (1) Anaplasma and Ehrlichia are only found in A. americanum, (2) each tick species has its own Rickettsia species, (3) a majority of questing-infected ticks are collected May-July, (4) A

Rickettsiosis transmitidas por garrapatas en las Américas: avances clínicos y epidemiológicos, y retos en el diagnóstico

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Marylin Hidalgo

2013-08-01

Full Text Available Las rickettsiosis son entidades clínicas de tipo zoonótico, causadas por bacterias intracelulares estrictas de los géneros Rickettsia y Orientia, pertenecientes a la familia Rickettsiaceae. Su ecología está determinada por factores ambientales y la presencia de vectores específicos que condicionan el establecimiento y la epidemiología en diferentes regiones del mundo. En las Américas, durante el siglo XX, únicamente eran reconocidas tres de estas enfermedades: la fiebre manchada de las Montañas Rocosas, el tifus epidémico y el tifus endémico. Sin embargo, apartir del año 2000 se han descrito mas de 10 especies diferentes previamente desconocidas en este continente, tanto en artrópodos como en casos clínicos, hecho que permite clasificarlas como entidades clínicas emergentes y reemergentes. Dadas las manifestaciones clínicas de las enfermedades causadas por rickettsias, siendo la gran mayoría inespecíficas y, por lo mismo, compartidas con otras enfermedades infecciosas, especialmente virales y bacterianas, han sido enmarcadas entre los diagnósticos diferenciales del síndrome febril agudo, tanto en áreas urbanas como tropicales. En la actualidad, se cuenta con métodos diagnóstico sdirectos e indirectos, que son útiles en la identificación del agente infeccioso, en este caso, causante de rickettsiosis.   doi: http://dx.doi.org/10.7705/biomedica.v33i0.1466

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

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Fernanda Gonçalves Batista

2010-12-01

processadas pela técnica de Reação de Imunofluorescência Indireta (RIFI, utilizando-se os antígenos de R. rickettsii e R. parkeri. Os carrapatos foram analisados por PCR para Rickettsia sp. e todos foram negativos. Seis cavalos (8,45% e 4 cães (20% foram identificados como soropositivos. Todos os proprietários desconheciam a relação de carrapatos com a FMB. Embora considerada uma área não endêmica, Almirante Tamandaré é um ambiente vulnerável à FMB e um controle eficiente de carrapatos deve ser implementado.

Rickettsia parkeri Rickettsiosis, Arizona, USA.

Science.gov (United States)

Herrick, Kristen L; Pena, Sandra A; Yaglom, Hayley D; Layton, Brent J; Moors, Amanda; Loftis, Amanda D; Condit, Marah E; Singleton, Joseph; Kato, Cecilia Y; Denison, Amy M; Ng, Dianna; Mertins, James W; Paddock, Christopher D

2016-05-01

In the United States, all previously reported cases of Rickettsia parkeri rickettsiosis have been linked to transmission by the Gulf Coast tick (Amblyomma maculatum). Here we describe 1 confirmed and 1 probable case of R. parkeri rickettsiosis acquired in a mountainous region of southern Arizona, well beyond the recognized geographic range of A. maculatum ticks. The likely vector for these 2 infections was identified as the Amblyomma triste tick, a Neotropical species only recently recognized in the United States. Identification of R. parkeri rickettsiosis in southern Arizona demonstrates a need for local ecologic and epidemiologic assessments to better understand geographic distribution and define public health risk. Education and outreach aimed at persons recreating or working in this region of southern Arizona would improve awareness and promote prevention of tickborne rickettsioses.

Antibodies against rickettsiae from spotted fever groups in horses from two mesoregions in the state of Santa Catarina, Brazil

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A.P. Medeiros

2013-12-01

Full Text Available Bacteria of the Rickettsia genus are agents of Brazilian Spotted Fever (BSF, a zoonotic disease which is difficult to diagnose, evolves quickly and can result in death. Antibodies against Rickettsia spp. in horses were studied, by means of Indirect Immunofluorescence Assay (IFAT ≥64, in 150 blood samples taken from animals in two Santa Catarina mesoregions (Planalto Serrano and Vale do Itajaí. The overall occurrence of Rickettsia spp. antibodies in horses was 18.66%, with cross-reactivity occurring in all positive samples for at least two of the species tested. Separately, according to the species, 25 (16.66% samples were positive for R. rickettsii, 15 (10% for R. parkeri, 22 (14.66% for R. amblyommii, 23 (15.33% for R. rhipicephali, 16 (10.66% for R. bellii and 19 (12.66% for R. felis. Only two animals resulted in a conclusive serodiagnosis, one for R. bellii and the other for R. rickettsii, at maximum dilutions of 1:4096 and 1:512, respectively. The occurrence of antibodies against Rickettsia spp. in horses from two mesoregions in the state of Santa Catarina indicates the movement of BSF agents in these sentinel animals and confirms the importance of studying spotted fever in the state of Santa Catarina.

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

International Nuclear Information System (INIS)

Oaks, S.C.Jr.; Osterman, J.V.

1979-01-01

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

Identification of Dermacentor reticulatus Ticks Carrying Rickettsia raoultii on Migrating Jackal, Denmark

DEFF Research Database (Denmark)

Schou, Kirstine Klitgaard; Chriél, Mariann; Isbrand, Anastasia

2017-01-01

From a migrating golden jackal (Canis aureus), we retrieved 21 live male Dermacentor reticulatus ticks, a species not previously reported from wildlife in Denmark. We identified Rickettsia raoultii from 18 (86%) of the ticks. This bacterium is associated with scalp eschar and neck lymphadenopathy...

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

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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

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

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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.

First molecular evidence of Anaplasma ovis and Rickettsia spp. in keds (Diptera: Hippoboscidae) of sheep and wild ruminants.

Science.gov (United States)

Hornok, Sándor; de la Fuente, José; Biró, Nóra; Fernández de Mera, Isabel G; Meli, Marina L; Elek, Vilmos; Gönczi, Eniko; Meili, Theres; Tánczos, Balázs; Farkas, Róbert; Lutz, Hans; Hofmann-Lehmann, Regina

2011-10-01

To evaluate the presence of rickettsial agents in hippoboscid flies with molecular methods, 81 sheep keds (Melophagus ovinus) were collected from 23 sheep, 144 deer keds (Lipoptena cervi) were caught in the environment, and a further 463 and 59 individuals of the latter species were obtained from fresh carcasses of 29 red deer and 17 roe deer, respectively. DNA was extracted individually or in pools. Anaplasma ovis was demonstrated in all examined sheep keds, and from one pool of free-living deer keds. Rickettsia helvetica or other, unidentified rickettsiae were also present in one pool of sheep keds, and in four pools of deer keds from both red deer and roe deer. This is the first account of polymerase chain reaction positivity of hippoboscid flies for A. ovis and rickettsiae. These results raise the possibility that-apart from cattle and roe deer as already reported-sheep and red deer might also play a reservoir role in the epidemiology of rickettsioses.

Direct evidence of Rickettsia typhi infection in Rhipicephalus sanguineus ticks and their canine hosts

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Karla Dzul-Rosado

2017-06-01

Full Text Available Murine typhus is a rickettsiosis caused by Rickettsia typhi, whose transmission is carried out by rat fleas in urban settlements as classically known, but it also has been related to cat fleas in a sub-urban alternative cycle that has been suggested by recent reports. These studies remarks that in addition to rats, other animals like cats, opossums and dogs could be implied in the transmission of Rickettsia typhi as infected fleas obtained from serologically positive animals have been detected in samples from endemic areas. In Mexico, the higher number of murine typhus cases have been detected in the Yucatan peninsula, which includes a great southeastern region of Mexico that shows ecologic characteristics similar to the sub-urban alternative cycle recently described in Texas and California at the United States. To find out which are the particular ecologic characteristics of murine typhus transmission in this region, we analyzed blood and Rhipicephalus sanguineus ticks obtained from domestic dogs by molecular approaches, demonstrating that both samples were infected by Rickettsia typhi. Following this, we obtained isolates that were analyzed by genetic sequencing to corroborate this infection in 100% of the analyzed samples. This evidence suggests for the first time that ticks and dogs could be actively participating in the transmission of murine typhus, in a role that requires further studies for its precise description.

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

Czech Academy of Sciences Publication Activity Database

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

First report of Rickettsia raoultii in field collected Dermacentor reticulatus ticks from Austria

Czech Academy of Sciences Publication Activity Database

Duscher, G. G.; Hodžić, A.; Weiler, M.; Vaux, A. G. C.; Rudolf, Ivo; Sixl, W.; Medlock, J. M.; Versteirt, V.; Hubálek, Zdeněk

2016-01-01

Roč. 7, č. 5 (2016), s. 720-722 ISSN 1877-959X Institutional support: RVO:68081766 Keywords : Rickettsia raoultii * Dermacentor reticulatus * TIBOLA * DEBONEL * Austria Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 3.230, year: 2016

Experimental infection in Cavia porcellus by infected Amblyomma ovale nymphs with Rickettsia sp. (Atlantic rainforest strain).

Science.gov (United States)

Brustolin, Joice Magali; da Silva Krawczak, Felipe; Alves, Marta Elena Machado; Weiller, Maria Amélia; de Souza, Camila Lopes; Rosa, Fábio Brum; Cadore, Gustavo Cauduro; Dos Anjos Lopes, Sônia Terezinha; Labruna, Marcelo Bahia; Vogel, Fernanda Silveira Flores; de Avila Botton, Sônia; Sangioni, Luís Antônio

2018-03-01

This study describes experimental infection of guinea pigs (Cavia porcellus) infested with naturally infected Amblyomma ovale nymphs with Rickettsia sp. (Atlantic rainforest strain), and the capacity of A. ovale nymphs to transmit this bacterium. Twenty-six guinea pigs were divided into the following groups: G1, 10 animals infested with uninfected A. ovale nymphs; G2, 10 animals infested with nymphs infected with Rickettsia sp. (Atlantic rainforest strain); and G3, 6 animals without tick infestation. Blood samples were taken 7, 14, 21, and 28 days post-infestation for serological and hematological tests. For histopathological analysis and rickettsial DNA detection, fragments of the spleen, lung, brain, and liver were harvested after euthanasia. The average feeding period for nymphs was 6.6 days for G1 and 6 days for G2. Hemolymph and PCR assays, performed to detect the causative agent in ticks, indicated that in G1, all ticks were negative, and in G2, all nymphs were positive by PCR and 80% (8/10) was positive by hemolymph tests. The only clinical change was skin scarring at the tick attachment site. Hematological parameters indicated leukopenia and total plasma protein (TPP) increased with decreased platelets in G1. In G2, leukocytosis, neutrophilia, monocytosis, an increase in platelets, and reduced TPP were observed. Only G2 guinea pigs were seroconverted (80%; 8/10). Histopathology tests indicated mild, diffuse hemosiderosis and mild, multifocal, follicular hyperplasia in the spleen. Molecular analysis did not detect Rickettsia sp. DNA in C. porcellus tissues. We demonstrated the capacity of A. ovale nymphs to transmit Rickettsia sp. (Atlantic rainforest strain) to guinea pigs.

Serosurvey of antibodies against spotted fever group Rickettsia spp. in horse farms in Northern Paraná, Brazil Soroprevalência de anticorpos contra Rickettsia spp. do grupo febre maculosa em equinos de haras no Norte do Paraná, Brasil

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Katia Tamekuni

2010-12-01

Full Text Available Brazilian spotted fever (BSF is an emerging disease most likely caused by Rickettsia rickettsii. The objective of the present study was to estimate the seroprevalence of BSF rickettsia infections in equines from six horse farms located in Londrina County, Paraná, Southern Brazil. Six owners of horse farms situated in Cambé, Santa Fé, Guaraci and Londrina municipalities participated in the study. All farms were located in areas where BSF has not been reported. A total of 273 horses were sampled and their sera were tested by indirect Immunofluorescence assay (IFA using R. rickettsii and R. parkeri antigens. Titers equal to and greater than 64 were considered positive. Of 273 sera tested, 15 (5.5% reacted to R. rickettsii and 5 (1.8% to R. parkeri. Five out of the six farms studied revealed seropositive animals and seropositivity rate ranged from 0 to 13%. The titers ranged from 64 to 512, and four samples had a titer of 512. Nine animals reacted to R. rickettsii with titers four-fold higher than those for R. parkeri. These results suggest that horses in Northern Paraná may have been exposed to rickettsiae identical or closely related to R. rickettsii.Febre Maculosa Brasileira (FMB é uma doença emergente, sendo Rickettsia rickettsii o seu principal agente etiológico. O objetivo deste estudo foi determinar a soroprevalência de rickettsia do grupo da febre maculosa em equinos de seis haras localizados nos municípios de Cambé, Santa Fé, Guaraci e Londrina. As propriedades eram localizadas na região Norte do Paraná onde casos de FMB ainda não foram diagnosticados. Foram colhidas amostras de sangue de 273 equinos, e os soros foram testados pela RIFI, usando R. rickettsii e R. parkeri como antígenos, considerando-se como positivos títulos >64. Entre 273 soros, 15 (5,5% reagiram contra R. rickettsii e 5 (1,8% para R. parkeri. Cinco de seis haras estudados tinham animais reativos, e a taxa de sororreatividade variou de 0 a 13%. Os t

First Report of Rickettsia Identical to R. slovaca in Colony-Originated D. variabilis in the United States: Detection, Laboratory Animal Model, and Vector Competence of Ticks.

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Zemtsova, Galina E; Killmaster, Lindsay F; Montgomery, Merrill; Schumacher, Lauren; Burrows, Matt; Levin, Michael L

2016-02-01

Ticks of the genus Dermacentor are known vectors of rickettsial pathogens in both the Old World and New World. In North America, Dermacentor variabilis and D. andersoni are vectors of Rickettsia rickettsii, while in Europe, D. marginatus and D. reticulatus transmit R. slovaca and R. raoultii, respectively. Neither the presence of R. slovaca in the Americas nor the ability of American tick species to maintain this pathogen have been reported. Here we describe detection of Rickettsia genetically identical to R. slovaca in D. variabilis, its molecular characterization, assessment of pathogenicity to guinea pigs, and vector competence of D. variabilis ticks. Ticks from a laboratory colony of D. variabilis, established from wild ticks and maintained on naïve NZW rabbits, tested positive for spotted fever group (SFG) Rickettsia by PCR. Analysis of 17 kDa gltA, rpoB, ompA, ompB, and sca4 genes revealed 100% identity to R. slovaca sequences available in the GenBank. New Zealand white rabbits fed upon by infected ticks seroconverted to SFG Rickettsia. Guinea pigs inoculated with the Rickettsia culture or infested by the infected ticks developed antibodies to SFG Rickettsia. The intensity of clinical signs and immune response were dependent on dose and route of infection. The identified Rickettsia was detected in all life stages of D. variabilis ticks, confirming transstadial and transovarial transmission. Thirty-six percent of uninfected larvae co-fed with infected nymphs on guinea pigs were PCR-positive and able to pass rickettsia to at least 11.7% of molted nymphs. To our knowledge, this is a first report of identification of a European pathogen R. slovaca or a highly similar agent in the American dog tick, D. variabilis. Considering pathogenicity of R. slovaca in humans, further laboratory and field studies are warranted to assess the relevance of the above findings to the public health and epidemiology of SFG rickettsioses in the United States.

Rickettsia asembonensis Characterization by Multilocus Sequence Typing of Complete Genes, Peru.

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Loyola, Steev; Flores-Mendoza, Carmen; Torre, Armando; Kocher, Claudine; Melendrez, Melanie; Luce-Fedrow, Alison; Maina, Alice N; Richards, Allen L; Leguia, Mariana

2018-05-01

While studying rickettsial infections in Peru, we detected Rickettsia asembonensis in fleas from domestic animals. We characterized 5 complete genomic regions (17kDa, gltA, ompA, ompB, and sca4) and conducted multilocus sequence typing and phylogenetic analyses. The molecular isolate from Peru is distinct from the original R. asembonensis strain from Kenya.

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

Czech Academy of Sciences Publication Activity Database

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

Torix group Rickettsia are widespread in Culicoides biting midges (Diptera: Ceratopogonidae), reach high frequency and carry unique genomic features.

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Pilgrim, Jack; Ander, Mats; Garros, Claire; Baylis, Matthew; Hurst, Gregory D D; Siozios, Stefanos

2017-10-01

There is increasing interest in the heritable bacteria of invertebrate vectors of disease as they present novel targets for control initiatives. Previous studies on biting midges (Culicoides spp.), known to transmit several RNA viruses of veterinary importance, have revealed infections with the endosymbiotic bacteria, Wolbachia and Cardinium. However, rickettsial symbionts in these vectors are underexplored. Here, we present the genome of a previously uncharacterized Rickettsia endosymbiont from Culicoides newsteadi (RiCNE). This genome presents unique features potentially associated with host invasion and adaptation, including genes for the complete non-oxidative phase of the pentose phosphate pathway, and others predicted to mediate lipopolysaccharides and cell wall modification. Screening of 414 Culicoides individuals from 29 Palearctic or Afrotropical species revealed that Rickettsia represent a widespread but previously overlooked association, reaching high frequencies in midge populations and present in 38% of the species tested. Sequence typing clusters the Rickettsia within the Torix group of the genus, a group known to infect several aquatic and hematophagous taxa. FISH analysis indicated the presence of Rickettsia bacteria in ovary tissue, indicating their maternal inheritance. Given the importance of biting midges as vectors, a key area of future research is to establish the impact of this endosymbiont on vector competence. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Development of a loop-mediated isothermal amplification (LAMP) assay for rapid screening of ticks and fleas for spotted fever group rickettsia.

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Noden, Bruce H; Martin, Jaclyn; Carrillo, Yisel; Talley, Justin L; Ochoa-Corona, Francisco M

2018-01-01

The importance of tick and flea-borne rickettsia infections is increasingly recognized worldwide. While increased focus has shifted in recent years to the development of point-of-care diagnostics for various vector-borne diseases in humans and animals, little research effort has been devoted to their integration into vector surveillance and control programs, particularly in resource-challenged countries. One technology which may be helpful for large scale vector surveillance initiatives is loop-mediated isothermal amplification (LAMP). The aim of this study was to develop a LAMP assay to detect spotted fever group (SFG) rickettsia DNA from field-collected ticks and fleas and compare with published end-point PCR results. A Spotted Fever Group rickettsia-specific loop-mediated isothermal amplification (SFGR-LAMP) assay was developed using primers based on a region of the R. rickettsii 17kDa protein gene. The sensitivity, specificity, and reproducibility of the assay were evaluated. The assay was then compared with the results of end-point PCR assays for pooled tick and flea samples obtained from field-based surveillance studies. The sensitivity of the SFGR-LAMP assay was 0.00001 ng/μl (25μl volume) which was 10 times more sensitive than the 17kDa protein gene end-point PCR used as the reference method. The assay only recognized gDNA from SFG and transitional group (TRG) rickettsia species tested but did not detect gDNA from typhus group (TG) rickettsia species or closely or distantly related bacterial species. The SFGR-LAMP assay detected the same positives from a set of pooled tick and flea samples detected by end-point PCR in addition to two pooled flea samples not detected by end-point PCR. To our knowledge, this is the first study to develop a functional LAMP assay to initially screen for SFG and TRG rickettsia pathogens in field-collected ticks and fleas. With a high sensitivity and specificity, the results indicate the potential use as a field

DNA Microarray Analysis of Human Monocytes Early Response Genes upon Infection with Rickettsia rickettsii

National Research Council Canada - National Science Library

Chao, Chien-Chung

2004-01-01

Rickettsia are arthropod-borne bacteria which have caused diseases that have had a military impact by sweeping through troops and incapacitating them, such as the so called Trench Fevers of World War I and II...

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

Science.gov (United States)

Rennoll-Bankert, Kristen E.; Rahman, M. Sayeedur; Gillespie, Joseph J.; Guillotte, Mark L.; Kaur, Simran J.; Lehman, Stephanie S.; Beier-Sexton, Magda; Azad, Abdu F.

2015-01-01

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(4,5)P2 at entry foci on the host plasma membrane was determined to be critical for invasion. Thus, we propose recruitment of PI(4,5)P2 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 for Ral

Cat fleas (Ctenocephalides felis) carrying Rickettsia felis and Bartonella species in Hong Kong.

Science.gov (United States)

Šlapeta, Jan; Lawrence, Andrea; Reichel, Michael P

2018-04-01

Fleas are commonly recorded on stray as well as domestic dogs and cats in Hong Kong. Fleas can be a major cause of pruritus in dogs and cats and also vectors of potentially zoonotic bacteria in the genera Rickettsia and Bartonella. Morphological examination of 174 fleas from dogs and cats living in Hong Kong revealed only cat fleas (Ctenocephalides felis). Cytochrome c oxidase subunit 1 gene (cox1) genotyping of 20 randomly selected specimens, revealed three cox1 haplotypes (HK-h1 to HK-h3). The most common haplotype was HK-h1 with 17 specimens (17/20, 85%). HK-h1 was identical to cox1 sequences of fleas in Thailand and Fiji. HK-h1 and HK-h2 form a distinct cat flea cox1 clade previously recognized as the Clade 3. HK-h3 forms a new Clade 6. A multiplex Bartonella and Rickettsia real-time PCR of DNA from 20 C. felis found Bartonella and Rickettsia DNA in three (15%) and ten (50%) C. felis, respectively. DNA sequencing confirmed the presence of R. felis, B. clarridgeiae and Bartonella henselae. This is the first reported study of that kind in Hong Kong, and further work is required to expand the survey of companion animals in the geographical region. The sampling of fleas on domestic cats and dogs in Hong Kong revealed them to be exclusively infested by the cat flea and to be harbouring pathogens of zoonotic potential. Copyright © 2017 Elsevier B.V. All rights reserved.

The occurrence of Spotted Fever Group (SFG) Rickettsiae in Ixodes ricinus ticks (Acari: Ixodidae) in northern Poland.

Science.gov (United States)

Stańczak, Joanna

2006-10-01

Ixodes ricinus, the most commonly observed tick species in Poland, is known vector of microorganisms pathogenic for humans as TBE virus, Borrelia burgdorferi s.1., Anaplasma phagocytophilum and Babesia sp. in this country. Our study aimed to find out whether this tick can also transmit also rickettsiae of the spotted fever group (SFG). DNA extracts from 560 ticks (28 females, 34 males, and 488 nymphs) collected in different wooded areas in northern Poland were examined by PCR for the detection of Rickettsia sp., using a primer set RpCS.877p and RpCS.1258n designated to amplify a 381-bp fragment of gltA gene. A total of 2.9% ticks was found to be positive. The percentage of infected females and males was comparable (10.5% and 11.8%, respectively) and 6.6-7.6 times higher than in nymphs (1.6%). Sequences of four PCR-derived DNA fragments (acc. no. DQ672603) demonstrated 99% similarity with the sequence of Rickettsia helvetica deposited in GenBank. The results obtained suggest the possible role of I. ricinus as a source of a microorganism, which recently has been identified as an agent of human rickettsioses in Europe.

Characterization of Spotted Fever Group Rickettsiae in Flea and Tick Specimens From Northern Peru

National Research Council Canada - National Science Library

Blair, Patrick J; Jiang, Ju; Schoeler, George B; Moron, Cecilia; Anaya, Elizabeth; Cespedes, Manuel; Cruz, Christopher; Felices, Vidal; Guevara, Carolina; Mendoza, Leonardo; Villaseca, Pablo; Sumner, John W; Richards, Allen L; Olson, James G

2004-01-01

... the focus of an outbreak of febrile disease in humans attributed, in part, to SFG rickettsia infections. Molecular identification of the etiologic agents from these samples was determined after partial sequencing of the 17-kDa common antigen gene...

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

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Dalva A. Portari Mancini

1983-12-01

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

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

Directory of Open Access Journals (Sweden)

Oscar Alberto Pérez Gutiérrez

2012-12-01

Full Text Available Introducción: la recidiva locorregional, luego de una intervención quirúrgica por cáncer de mama, es una gran preocupación para el paciente y una frustración para el cirujano actuante. Objetivos: realizar un estudio descriptivo de las variables asociadas a la recurrencia tumoral, en 949 pacientes operadas. Métodos: se confeccionó una base de datos con las pacientes operadas desde 2005 hasta 2010, se identificaron las variables y análisis univariables y multivariables para determinar si existió asociación estadística. Resultados: se apreció que la incidencia fue de 4,4 %. La intervención quirúrgica previa más frecuente fue la mastectomía radical modificada en 52,4 %, y 26,2 % de los casos que tenían metástasis ganglionares axilares en ese momento. El tipo histológico más frecuente fue el carcinoma ductal infiltrante, de alto grado de malignidad. La infiltración vascular y linfática estuvo presente en 42,8 %. El tratamiento definitivo más empleado fue la exéresis de la recidiva más radioterapia. El análisis multivariables solo asoció la metástasis ganglionar con la reaparición de la enfermedad. Conclusiones: la metástasis ganglionar axilar sigue siendo un factor de mal pronóstico en el seguimiento extenso de la paciente.Introduction: locoregional relapses after a breast cancer surgery is a big concern for the patient and a frustration to the performing surgeon. Objectives: to perform a descriptive study of the tumor recurrence-associated variables in 949 surgical patients. Methods: a database containing the data from operated patients in the period of 2005 through 2010 was made; the variables were identified and the univariate and multivariate analyses allowed determining the probable statistical association. Results: at was observed that the incidence of locoregional recurrence was 4.4 %. The most common previous surgery was modified radical mastectomy in 52.4 % and 26.2 % of cases with axillary ganglionic

Phylogenetic Analysis of a Novel Molecular Isolate of Spotted Fever Group Rickettsiae from Northern Peru

National Research Council Canada - National Science Library

Jiang, Ju; Blair, Patrick J; Felices, Vidal; Moron, Cecilia; Cespedes, Manuel; Anaya, Elizabeth; Schoeler, George B; Sumner, John W; Olson, James G; Richards, Allen L

2005-01-01

... (SFG) rickettsia. Following nested polymerase chain reaction (PCR) amplification of the 17-kDa gene, gltA, ompB, ompA, and sca4, amplicons were purified, sequenced, and compared to those downloaded from GenBank...

Outbreak of Rickettsia africae infections in participants of an adventure race in South Africa.

Science.gov (United States)

Fournier, P E; Roux, V; Caumes, E; Donzel, M; Raoult, D

1998-08-01

African tick-bite fever, caused by Rickettsia africae and transmitted by Amblyomma ticks, is an emerging rickettsiosis in southern Africa. Because of increased tourism to this area, several cases in tourists have been reported recently. We report 13 cases of R. africae infection diagnosed in France that occurred in competitors returning from an adventure race in South Africa and compare our data with previously reported findings. Most of our patients presented with fever, headache, multiple inoculation eschars, and regional lymphadenopathies, but only 15.4% had a cutaneous rash. Diagnosis was confirmed either by isolation of R. africae from an eschar biopsy specimen or by serological methods, including cross-adsorption between R. africae and Rickettsia conorii. The purpose of this study was to raise physicians' awareness of R. africae infections in an attempt to facilitate the rapid diagnosis and treatment of imported African tick-bite fever in developed countries.

A Molecular Survey for Francisella tularensis and Rickettsia spp. in Haemaphysalis leporispalustris (Acari: Ixodidae) in Northern California.

Science.gov (United States)

Roth, Tara; Lane, Robert S; Foley, Janet

2017-03-01

Francisella tularensis and Rickettsia spp. have been cultured from Haemaphysalis leporispalustris Packard, but their prevalence in this tick has not been determined using modern molecular methods. We collected H. leporispalustris by flagging vegetation and leaf litter and from lagomorphs (Lepus californicus Gray and Sylvilagus bachmani (Waterhouse)) in northern California. Francisella tularensis DNA was not detected in any of 1,030 ticks tested by polymerase chain reaction (PCR), whereas 0.4% of larvae tested in pools, 0 of 117 individual nymphs, and 2.3% of 164 adult ticks were PCR-positive for Rickettsia spp. Positive sites were Laurel Canyon Trail in Tilden Regional Park in Alameda Contra Costa County, with a Rickettsia spp. prevalence of 0.6% in 2009, and Hopland Research and Extension Center in Mendocino County, with a prevalence of 4.2% in 1988. DNA sequencing revealed R. felis, the agent of cat-flea typhus, in two larval pools from shaded California bay and live oak leaf litter in Contra Costa County and one adult tick from a L. californicus in chaparral in Mendocino County. The R. felis in unfed, questing larvae demonstrates that H. leporispalustris can transmit this rickettsia transovarially. Although R. felis is increasingly found in diverse arthropods and geographical regions, prior literature suggests a typical epidemiological cycle involving mesocarnivores and the cat flea, Ctenocephalides felis. To our knowledge, this is the first report of R. felis in H. leporispalustris. Natural infection and transovarial transmission of this pathogen in the tick indicate the existence of a previously undocumented wild-lands transmission cycle that may intersect mesocarnivore-reservoired cycles and collectively affect human health risk. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

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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

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

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

2012-04-01

Rickettsiae are obligate intracellular pathogens that are transmitted to humans by arthropod vectors and cause diseases such as spotted fever and typhus. Although rickettsiae require the host cell actin cytoskeleton for invasion, the cytoskeletal proteins that mediate this process have not been completely described. To identify the host factors important during cell invasion by Rickettsia parkeri, a member of the spotted fever group (SFG), we performed an RNAi screen targeting 105 proteins in Drosophila melanogaster S2R+ cells. The screen identified 21 core proteins important for invasion, including the GTPases Rac1 and Rac2, the WAVE nucleation-promoting factor complex and the Arp2/3 complex. In mammalian cells, including endothelial cells, the natural targets of R. parkeri, the Arp2/3 complex was also crucial for invasion, while requirements for WAVE2 as well as Rho GTPases depended on the particular cell type. We propose that R. parkeri invades S2R+ arthropod cells through a primary pathway leading to actin nucleation, whereas invasion of mammalian endothelial cells occurs via redundant pathways that converge on the host Arp2/3 complex. Our results reveal a key role for the WAVE and Arp2/3 complexes, as well as a higher degree of variation than previously appreciated in actin nucleation pathways activated during Rickettsia invasion. © 2011 Blackwell Publishing Ltd.

Rickettsia rickettsii infecting Rhipicephalus sanguineus sensu lato (Latreille 1806), in high altitude atlantic forest fragments, Ceara State, Brazil.

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Silva, Arannadia Barbosa; Duarte, Myrian Morato; da Costa Cavalcante, Robson; de Oliveira, Stefan Vilges; Vizzoni, Vinicius Figueiredo; de Lima Duré, Ana Íris; de Melo Iani, Felipe Campos; Machado-Ferreira, Erik; Gazêta, Gilberto Salles

2017-09-01

In Brazil, Spotted Fever (SF) is caused by Rickettsia rickettsii and Rickettsia parkeri strain Atlantic Forest. In recent years, several human cases of a milder SF have been reported from the Maciço de Baturité region of Ceará State. Previous studies in this region found R. parkeri strain Atlantic Forest to be present in Rhipicephalus sanguineus sensu lato and Amblyomma ovale ticks. The present study isolated and identified the Rickettsia spp. present in this new endemic area in Brazil. In March 2015, R. sanguineus s.l. and A. ovale were collected in rural areas of the Maciço de Baturité region, and subjected to the isolation technique. A bacterium was isolated from one R. sanguineus s.l., which phylogenetic analysis clustered to the R. rickettsii group. In conclusion, R. rickettsii bacteria is circulating in the studied area and may in future have an impact on the clinical diagnoses and consequently cause changes in the profile of the disease in the region. In addition, we suggest the increase of epidemiological and environmental surveillance in the area, in order to prevent Brazilian Spotted Fever cases. Copyright © 2017. Published by Elsevier B.V.

Seroprevalence of rickettsia spp. and a study of the tick fauna in dogs from the municipality of Seropédica, State of Rio de Janeiro

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Matheus Dias Cordeiro

2015-12-01

Full Text Available The aim of this study was to investigate the presence of anti-Rickettsia spp. antibodies, the tick fauna, and the ticks that are carriers of rickettsiae of the spotted fever group (SFG. About 68 (24% of the 283 serum samples tested by indirect immunofluorescence (IFA reacted against the R. rickettsii crude antigen. The titers varied between 1:64 and 1:512. At the time of collection, 189 (64.5% of the 293 dogs included in this study, were infested with ticks. Ticks classified as Rhipicephalus sanguineus and Amblyomma sculptum were identified. None of the ticks examined for SFG rickettsiae using polymerase chain reaction (PCR were positive. The presence of the anti-R. rickettsii antibodies detected by IFA, albeit at low titers, suggests the circulation of SFG rickettsiae, which requires permanent surveillance because there are records on human fatalities related to spotted fever and to avoid any future threats to the students moving extensively in the areas near of the Rural Federal University of Rio de Janeiro.

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

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K. Dzul-Rosado

2013-09-01

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

Molecular Pathogenesis of Rickettsioses and Development of Novel Anti-Rickettsia Treatment by Comginatorial Peptide-Based Libraries

National Research Council Canada - National Science Library

Walker, David H; Olano, Juan P

2005-01-01

...) library and challenge with R. prowazekii, R. rickettsii, and 0. tsutsugamushi; 2) To determine the role of NF-KB, cytokines, ROS and NO in intracellular killing of rickettsia-infected monolayers containing adapteins and 3...

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

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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.

Two Pathogens and One Disease: Detection and Identification of Flea-Borne Rickettsiae in Areas Endemic for Murine Typhus in California

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EREMEEVA, MARINA E.; KARPATHY, SANDOR E.; KRUEGER, LAURA; HAYES, ERICA K.; WILLIAMS, ASHLEY M.; ZALDIVAR, YAMITZEL; BENNETT, STEPHEN; CUMMINGS, ROBERT; TILZER, ART; VELTEN, ROBERT K.; KERR, NELSON; DASCH, GREGORY A.; HU, RENJIE

2018-01-01

Results of an environmental assessment conducted in a newly emergent focus of murine typhus in southern California are described. Opossums, Didelphis virginiana Kerr, infested with cat fleas, Ctenocephalides felis Buché, in the suburban area were abundant. Animal and flea specimens were tested for the DNA of two flea-borne rickettsiae, Rickettsia typhi and Rickettsia felis. R. felis was commonly detected in fleas collected throughout this area while R. typhi was found at a much lower prevalence in the vicinity of just 7 of 14 case-patient homes identified. DNA of R. felis, but not R. typhi, was detected in renal, hepatic, and pulmonary tissues of opossums. In contrast, there were no hematologic polymerase chain reaction findings of R. felis or R. typhi in opossums, rats, and cats within the endemic area studied. Our data suggest a significant probability of human exposure to R. felis in the area studied; however, disease caused by this agent is not recognized by the medical community and may be misdiagnosed as murine typhus using nondiscriminatory serologic methods. PMID:23270180

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

International Nuclear Information System (INIS)

Cai, J.; Winkler, H.H.

1997-01-01

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)

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

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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.

A serological and molecular survey of Babesia vogeli, Ehrlichia canis and Rickettsia spp. among dogs in the state of Maranhão, northeastern Brazil

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Andréa Pereira da Costa

Full Text Available This study evaluated exposure and infection by tick-borne agents (Babesia vogeli, Ehrlichia canis and Rickettsia spp. in 172 dogs in rural areas and 150 dogs in urban areas of the municipality of Chapadinha, state of Maranhão, northeastern Brazil, using molecular and serological methods. Overall, 16.1% of the sampled dogs (52/322 were seroreactive to B. vogeli, with endpoint titers ranging from 40 to 640. For E. canis, 14.6% of the dogs (47/322 were seroreactive, with endpoint titers from 80 to 163,840. Antibodies reactive to at least one of the five species of Rickettsia were detected in 18.9% of the dogs (61/322, with endpoint titers ranging from 64 to 4,096. High endpoint titers were observed for Rickettsia amblyommii. Three (0.9% and nine (2.8% canine blood samples were PCR-positive for Babesia spp. and E. canis. The ticks collected from urban dogs were all Rhipicephalus sanguineus sensu lato, whereas the rural dogs were infested by R. sanguineus s.l, Amblyomma cajennense sensu lato and Amblyomma ovale. One A. ovale tick was found to be infected by Rickettsia bellii. This study provides an epidemiological background for controlling and preventing canine tick-borne diseases in a neglected region of Brazil.

Radioiodination of an outer membrane protein in intact Rickettsia prowazekii

International Nuclear Information System (INIS)

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

1980-01-01

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

Molecular Survey on Rickettsia spp., Anaplasma phagocytophilum, Borrelia burgdorferi Sensu Lato, and Babesia spp. in Ixodes ricinus Ticks Infesting Dogs in Central Italy.

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Morganti, Giulia; Gavaudan, Stefano; Canonico, Cristina; Ravagnan, Silvia; Olivieri, Emanuela; Diaferia, Manuela; Marenzoni, Maria Luisa; Antognoni, Maria Teresa; Capelli, Gioia; Silaghi, Cornelia; Veronesi, Fabrizia

2017-11-01

Dogs are a common feeding hosts for Ixodes ricinus and may act as reservoir hosts for zoonotic tick-borne pathogens (TBPs) and as carriers of infected ticks into human settings. The aim of this work was to evaluate the presence of several selected TBPs of significant public health concern by molecular methods in I. ricinus recovered from dogs living in urban and suburban settings in central Italy. A total of 212 I. ricinus specimens were collected from the coat of domestic dogs. DNA was extracted from each specimen individually and tested for Rickettsia spp., Borrelia burgdorferi sensu lato, Babesia spp., and Anaplasma phagocytophilum, using real-time and conventional PCR protocols, followed by sequencing. Sixty-one ticks (28.8%) tested positive for TBPs; 57 samples were infected by one pathogen, while four showed coinfections. Rickettsia spp. was detected in 39 specimens (18.4%), of which 32 were identified as Rickettsia monacensis and seven as Rickettsia helvetica. Twenty-two samples (10.4%) tested positive for A. phagocytophilum; Borrelia lusitaniae and Borrelia afzelii were detected in two specimens and one specimen, respectively. One tick (0.5%) was found to be positive for Babesia venatorum (EU1). Our findings reveal the significant exposure of dogs to TBPs of public health concern and provide data on the role of dogs in the circulation of I. ricinus-borne pathogens in central Italy.

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

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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. Copyright © 2016 Elsevier GmbH. All rights reserved.

Differences in intracellular fate of two spotted fever group Rickettsia in macrophage-like cells

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Pedro Curto

2016-07-01

Full Text Available Spotted fever group (SFG rickettsiae are recognized as important agents of human tick-borne diseases worldwide, such as Mediterranean spotted fever (R. conorii and Rocky Mountain spotted fever (R. rickettsii. Recent studies in several animal models have provided evidence of non-endothelial parasitism by pathogenic SFG Rickettsia species, suggesting that the interaction of rickettsiae with cells other than the endothelium may play an important role in pathogenesis of rickettsial diseases. These studies raise the hypothesis that the role of macrophages in rickettsial pathogenesis may have been underappreciated. Herein, we evaluated the ability of two SFG rickettsial species, R. conorii (a recognized human pathogen and R. montanensis (a non-virulent member of SFG to proliferate in THP-1 macrophage-like cells, or within non-phagocytic cell lines. Our results demonstrate that R. conorii was able to survive and proliferate in both phagocytic and epithelial cells in vitro. In contrast, R. montanensis was able to grow in non-phagocytic cells, but was drastically compromised in the ability to proliferate within both undifferentiated and PMA-differentiated THP-1 cells. Interestingly, association assays revealed that R. montanensis was defective in binding to THP-1-derived macrophages; however, the invasion of the bacteria that are able to adhere did not appear to be affected. We have also demonstrated that R. montanensis which entered into THP-1-derived macrophages were rapidly destroyed and partially co-localized with LAMP-2 and cathepsin D, two markers of lysosomal compartments. In contrast, R. conorii was present as intact bacteria and free in the cytoplasm in both cell types. These findings suggest that a phenotypic difference between a non-pathogenic and a pathogenic SFG member lies in their respective ability to proliferate in macrophage-like cells, and may provide an explanation as to why certain SFG rickettsial species are not associated with

Genetic Diversity of the Invasive Gall Wasp Leptocybe invasa (Hymenoptera: Eulophidae) and of its Rickettsia Endosymbiont, and Associated Sex-Ratio Differences

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Nugnes, Francesco; Gebiola, Marco; Monti, Maurilia Maria; Gualtieri, Liberata; Giorgini, Massimo; Wang, Jianguo; Bernardo, Umberto

2015-01-01

The blue-gum chalcid Leptocybe invasa Fisher & LaSalle (Hymenoptera: Eulophidae) is a gall wasp pest of Eucalyptus species, likely native to Australia. Over the past 15 years it has invaded 39 countries on all continents where eucalypts are grown. The worldwide invasion of the blue gum chalcid was attributed to a single thelytokous morphospecies formally described in 2004. Subsequently, however, males have been recorded in several countries and the sex ratio of field populations has been found to be highly variable in different areas. In order to find an explanation for such sex ratio differences, populations of L. invasa from a broad geographical area were screened for the symbionts currently known as reproductive manipulators, and both wasps and symbionts were genetically characterized using multiple genes. Molecular analyses suggested that L. invasa is in fact a complex of two cryptic species involved in the rapid and efficient spread of the wasp, the first recovered from the Mediterranean region and South America, the latter from China. All screened specimens were infected by endosymbiotic bacteria belonging to the genus Rickettsia. Two closely related Rickettsia strains were found, each infecting one of the two putative cryptic species of L. invasa and associated with different average sex ratios. Rickettsia were found to be localized in the female reproductive tissues and transovarially transmitted, suggesting a possible role of Rickettsia as the causal agent of thelytokous parthenogenesis in L. invasa. Implications for the variation of sex ratio and for the management of L. invasa are discussed. PMID:25970681

Genetic Diversity of the Invasive Gall Wasp Leptocybe invasa (Hymenoptera: Eulophidae and of its Rickettsia Endosymbiont, and Associated Sex-Ratio Differences.

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Francesco Nugnes

Full Text Available The blue-gum chalcid Leptocybe invasa Fisher & LaSalle (Hymenoptera: Eulophidae is a gall wasp pest of Eucalyptus species, likely native to Australia. Over the past 15 years it has invaded 39 countries on all continents where eucalypts are grown. The worldwide invasion of the blue gum chalcid was attributed to a single thelytokous morphospecies formally described in 2004. Subsequently, however, males have been recorded in several countries and the sex ratio of field populations has been found to be highly variable in different areas. In order to find an explanation for such sex ratio differences, populations of L. invasa from a broad geographical area were screened for the symbionts currently known as reproductive manipulators, and both wasps and symbionts were genetically characterized using multiple genes. Molecular analyses suggested that L. invasa is in fact a complex of two cryptic species involved in the rapid and efficient spread of the wasp, the first recovered from the Mediterranean region and South America, the latter from China. All screened specimens were infected by endosymbiotic bacteria belonging to the genus Rickettsia. Two closely related Rickettsia strains were found, each infecting one of the two putative cryptic species of L. invasa and associated with different average sex ratios. Rickettsia were found to be localized in the female reproductive tissues and transovarially transmitted, suggesting a possible role of Rickettsia as the causal agent of thelytokous parthenogenesis in L. invasa. Implications for the variation of sex ratio and for the management of L. invasa are discussed.

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

Czech Academy of Sciences Publication Activity Database

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: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.690, year: 2015

Detection of a novel Rickettsia sp. in soft ticks (Acari: Argasidae) in Algeria.

Science.gov (United States)

Lafri, Ismail; Leulmi, Hamza; Baziz-Neffah, Fadhila; Lalout, Reda; Mohamed, Chergui; Mohamed, Karakallah; Parola, Philippe; Bitam, Idir

2015-01-01

Argasid ticks are vectors of viral and bacterial agents that can infect humans and animals. In Africa, relapsing fever borreliae are neglected arthropod-borne pathogens that cause mild to deadly septicemia and miscarriage. It would be incredibly beneficial to be able to simultaneous detect and identify other pathogens transmitted by Argasid ticks. From 2012 to 2014, we conducted field surveys in 4 distinct areas of Algeria. We investigated the occurrence of soft ticks in rodent burrows and yellow-legged gull (Larus michahellis) nests in 10 study sites and collected 154 soft ticks. Molecular identification revealed the occurrence of two different soft tick genera and five species, including Carios capensis in yellow-legged gull nests and Ornithodoros occidentalis, Ornithodoros rupestris, Ornithodoros sonrai, Ornithodoros erraticus in rodent burrows. Rickettsial DNA was detected in 41/154, corresponding to a global detection rate of 26.6%. Sequences of the citrate synthase (gltA) gene suggest that this agent is a novel spotted fever group Rickettsia. For the first time in Algeria, we characterize a novel Rickettsia species by molecular means in soft ticks. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Conjuntivite granulomatosa atípica causada pela doença da arranhadura do gato: relato de caso Cat-scratch disease causing atypical granulomatous conjunctivitis: case report

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Alexandre Hassler Príncipe de Oliveira

2004-06-01

Full Text Available Relatamos caso de paciente do sexo feminino, brasileira, 23 anos, residente na Alemanha, que cursou com quadro de conjuntivite granulomatosa bilateral crônica, sem acometimento ganglionar, não responsiva a tratamento tópico. A pesquisa laboratorial confirmou diagnóstico de conjuntivite por Bartonella henselae. O caso demonstra que a ausência de acometimento ganglionar não exclui o diagnóstico de doença da arranhadura do gato.We report a case of a 23-year-old female patient, Brazilian, resident of Germany, who presented with a bilateral chronic granulomatous conjunctivitis, without lymphoadenopathy and irresponsive to topical treatment. Laboratorial work-up confirmed Bartonella henselae as the etiologic agent. The case shows that the absence of lymphoadenopathy does not exclude the diagnosis of cat-scratch disease.

Molecular surveillance of spotted fever group rickettsioses in wildlife and detection of Rickettsia sibirica in a Topi (Damaliscus lunatus ssp. jimela) in Kenya.

Science.gov (United States)

Ndeereh, David; Thaiyah, Andrew; Muchemi, Gerald; Miyunga, Antoinette A

2017-01-30

Spotted fever group rickettsioses are a group of tick-borne zoonotic diseases caused by intracellular bacteria of the genus Rickettsia. The diseases are widely reported amongst international travellers returning from most sub-Saharan Africa with fever, yet their importance in local populations largely remains unknown. Although this has started to change and recently there have been increasing reports of the diseases in livestock, ticks and humans in Kenya, they have not been investigated in wildlife. We examined the presence, prevalence and species of Rickettsia present in wildlife in two regions of Kenya with a unique human-wildlife-livestock interface. For this purpose, 79 wild animals in Laikipia County and 73 in Maasai Mara National Reserve were sampled. DNA extracted from blood was tested using the polymerase chain reaction (PCR) to amplify the intergenic spacer rpmE-tRNAfMet and the citrate synthase-encoding gene gltA. Rickettsial DNA was detected in 2 of the 79 (2.5%) animals in Laikipia and 4 of the 73 (5.5%) in Maasai Mara. The PCR-positive amplicons of the gltA gene were sequenced to determine the detected Rickettsia species. This revealed Rickettsia sibirica in a Topi (Damaliscus lunatus ssp. jimela). This is the first report of spotted fever group rickettsioses in wildlife and the first to report R. sibirica in Kenya. The finding demonstrates the potential role of wild animals in the circulation of the diseases.

Molecular surveillance of spotted fever group rickettsioses in wildlife and detection of Rickettsia sibirica in a Topi (Damaliscus lunatus ssp. jimela in Kenya

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David Ndeereh

2017-01-01

Full Text Available Spotted fever group rickettsioses are a group of tick-borne zoonotic diseases caused by intracellular bacteria of the genus Rickettsia. The diseases are widely reported amongst international travellers returning from most sub-Saharan Africa with fever, yet their importance in local populations largely remains unknown. Although this has started to change and recently there have been increasing reports of the diseases in livestock, ticks and humans in Kenya, they have not been investigated in wildlife. We examined the presence, prevalence and species of Rickettsia present in wildlife in two regions of Kenya with a unique human–wildlife–livestock interface. For this purpose, 79 wild animals in Laikipia County and 73 in Maasai Mara National Reserve were sampled. DNA extracted from blood was tested using the polymerase chain reaction (PCR to amplify the intergenic spacer rpmE-tRNAfMet and the citrate synthase-encoding gene gltA. Rickettsial DNA was detected in 2 of the 79 (2.5% animals in Laikipia and 4 of the 73 (5.5% in Maasai Mara. The PCR-positive amplicons of the gltA gene were sequenced to determine the detected Rickettsia species. This revealed Rickettsia sibirica in a Topi (Damaliscus lunatus ssp. jimela. This is the first report of spotted fever group rickettsioses in wildlife and the first to report R. sibirica in Kenya. The finding demonstrates the potential role of wild animals in the circulation of the diseases.

Detection of Rickettsia Species in Fleas Collected from Cats in Regions Endemic and Nonendemic for Flea-Borne Rickettsioses in California.

Science.gov (United States)

Billeter, Sarah A; Diniz, Pedro Paulo Vissotto de Paiva; Jett, Lindsey A; Wournell, Andrea L; Kjemtrup, Anne M; Padgett, Kerry A; Yoshimizu, Melissa Hardstone; Metzger, Marco E; Barr, Margaret C

2016-03-01

Rickettsia typhi, transmitted by rat fleas, causes most human flea-borne rickettsioses worldwide. Another rickettsia, Rickettsia felis, found in cat fleas, Ctenocephalides felis, has also been implicated as a potential human pathogen. In the continental United States, human cases of flea-borne rickettsioses are reported primarily from the southern regions of Texas and California where the cat flea is considered the principal vector. In California, more than 90% of locally acquired human cases are reported from suburban communities within Los Angeles and Orange counties despite the almost ubiquitous presence of cat fleas and their hosts throughout the state. The objective of this study is to assess the presence and infection rate of Rickettsia species in cat fleas from selected endemic and nonendemic regions of California. Cat fleas were collected from cats in Los Angeles County (endemic region) and Sacramento and Contra Costa counties (nonendemic region). Sequencing of 17 amplicons confirmed the presence of R. felis in both the endemic and non-endemic regions with a calculated maximum likelihood estimation of 131 and 234 per 1000 fleas, respectively. R. typhi was not detected in any flea pools. Two R. felis-like genotypes were also detected in fleas from Los Angeles County; Genotype 1 was detected in 1 flea pool and Genotype 2 was found in 10 flea pools. Genotype 1 was also detected in a single flea pool from Sacramento County. Results from this study show that R. felis is widespread in cat flea populations in both flea-borne rickettsioses endemic and nonendemic regions of California, suggesting that a high prevalence of this bacterium in cat fleas does not predispose to increased risk of human infection. Further studies are needed to elucidate the role of R. felis and the two R. felis-like organisms as etiologic agents of human flea-borne rickettsioses in California.

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

DEFF Research Database (Denmark)

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 high...

Liolaemus lizards (Squamata: Liolaemidae) as hosts for the nymph of Amblyomma parvitarsum (Acari: Ixodidae), with notes on Rickettsia infection.

Science.gov (United States)

Muñoz-Leal, Sebastián; Tarragona, Evelina L; Martins, Thiago F; Martín, Claudia M; Burgos-Gallardo, Freddy; Nava, Santiago; Labruna, Marcelo B; González-Acuña, Daniel

2016-10-01

Adults of Amblyomma parvitarsum are common ectoparasites of South American camelids of the genera Lama and Vicugna, occuring in highlands of Argentina, Bolivia, Chile, Peru and also in Argentinean Patagonia. Whereas larval stages of this tick are known to feed on small lizards, host records for the nymphal instar have remained unreported. Supported by morphological and molecular analyses, herein we report A. parvitarsum nymphs parasitizing two Liolaemus species (Reptilia: Squamata) in the Andean Plateau of Argentina and Chile. Additionally, by a PCR screening targetting gltA and ompA genes, DNA of Rickettsia was detected in one of the collected nymphs. Obtained sequences of this agent were identical to a recent Rickettsia sp. described infecting adults of this tick species in Chile and Argentina.

Two Bacterial Genera, Sodalis and Rickettsia, Associated with the Seal Louse Proechinophthirus fluctus (Phthiraptera: Anoplura)

Science.gov (United States)

Allen, Julie M.; Koga, Ryuichi; Fukatsu, Takema; Sweet, Andrew D.; Johnson, Kevin P.; Reed, David L.

2016-01-01

ABSTRACT Roughly 10% to 15% of insect species host heritable symbiotic bacteria known as endosymbionts. The lice parasitizing mammals rely on endosymbionts to provide essential vitamins absent in their blood meals. Here, we describe two bacterial associates from a louse, Proechinophthirus fluctus, which is an obligate ectoparasite of a marine mammal. One of these is a heritable endosymbiont that is not closely related to endosymbionts of other mammalian lice. Rather, it is more closely related to endosymbionts of the genus Sodalis associated with spittlebugs and feather-chewing bird lice. Localization and vertical transmission of this endosymbiont are also more similar to those of bird lice than to those of other mammalian lice. The endosymbiont genome appears to be degrading in symbiosis; however, it is considerably larger than the genomes of other mammalian louse endosymbionts. These patterns suggest the possibility that this Sodalis endosymbiont might be recently acquired, replacing a now-extinct, ancient endosymbiont. From the same lice, we also identified an abundant bacterium belonging to the genus Rickettsia that is closely related to Rickettsia ricketsii, a human pathogen vectored by ticks. No obvious masses of the Rickettsia bacterium were observed in louse tissues, nor did we find any evidence of vertical transmission, so the nature of its association remains unclear. IMPORTANCE Many insects are host to heritable symbiotic bacteria. These heritable bacteria have been identified from numerous species of parasitic lice. It appears that novel symbioses have formed between lice and bacteria many times, with new bacterial symbionts potentially replacing existing ones. However, little was known about the symbionts of lice parasitizing marine mammals. Here, we identified a heritable bacterial symbiont in lice parasitizing northern fur seals. This bacterial symbiont appears to have been recently acquired by the lice. The findings reported here provide insights

Registro de actividad eléctrica en la retina de una rata albina empleando una matriz de microelectrodos

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Edwin Alexander Cerquera

2015-09-01

Full Text Available Las matrices de microelectrodos son dispositivos que permiten la detección de potenciales de acción o espigas en poblaciones de células excitables, ofreciendo varias aplicaciones en el campo de las neurociencias y la biología. Este trabajo muestra un protocolo para el registro de espigas en una población de células ganglionares retinales empleando una matriz de microelectrodos. La retina de una rata albina fue extraída y preparada para ser estimulada in vitro con luz led blanca, con el fin de registrar sus espigas evocadas ante estos estímulos. Cada microelectrodo puede registrar espigas de más de una célula ganglionar, razón por la cual se determinó a qué célula pertenece cada espiga aplicando un procedimiento conocido como “clasificación de espigas”. El trabajo permitió obtener el registro de un periodo de estimulación y otro de no estimulación, con el fin de representar los potenciales de acción evocados con luz y los espontáneos. Los registros fueron almacenados para visualizar las espigas de las células ganglionares y poder aplicar la herramienta de clasificación de espigas. De este modo, se almacenan los instantes de tiempo en los cuales cada célula ganglionar registrada generó potenciales de acción. Este trabajo conllevó al establecimiento de un protocolo de experimentación básico enfocado al uso de matrices MEA en el laboratorio de adquisición de potenciales extracelulares de la Universidad Antonio Nariño Sede Bogotá, no sólo para caracterizar los potenciales de acción de células ganglionares retinales, sino también para otro tipo de células que puedan ser estudiadas empleando matrices de microelectrodos.

Characterization of rickettsia rickettsii in a case of Fatal Brazilian spotted fever in the city of Rio de Janeiro, Brazil

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Cristiane Lamas

Full Text Available A lethal case of Brazilian spotted fever (BSF is presented. Clinical features were initially of gastrointestinal involvement and evolved with progression to septic shock, meningoencephalitis and death on the 6th day of illness. Indirect immunofluorescence assay (IFA for spotted fever group rickettsia (SFGR was non-reactive. Diagnosis was confirmed by the polymerase chain reaction (PCR and the nucleotide sequencing of a fragment of the ompA gene showed 100% homology to Rickettsia rickettsii. BSF has not been reported in the city of Rio de Janeiro in the last three decades, and the present description should alert the clinicians to its presence in urban Rio de Janeiro, and to the differential diagnosis with dengue fever, gastroenteritis, leptospirosis and bacterial septic shock, among others.

Molecular detection of spotted fever group Rickettsia in Dermacentor silvarum from a forest area of northeastern China

NARCIS (Netherlands)

W.-C. Cao (Wu-Chun); L. Zhan (Lin); S.J. de Vlas (Sake); B.-H. Wen (Bo-Hai); H. Yang (Honghui); J.H. Richardus (Jan Hendrik); J.D.F. Habbema (Dik)

2008-01-01

textabstractIn total, 676 Dermacentor silvarum Olenev (Acari: Ixodidae) from a forest area of Jilin Province in northeastern China were examined by polymerase chain reaction for the presence of spotted fever group (SFG) Rickettsia. The overall positive rate was 10.7%, with a 95% confidence interval

Co-Infection of Rickettsia rickettsii and Streptococcus pyogenes: Is Fatal Rocky Mountain Spotted Fever Underdiagnosed?

Science.gov (United States)

Raczniak, Gregory A.; Kato, Cecilia; Chung, Ida H.; Austin, Amy; McQuiston, Jennifer H.; Weis, Erica; Levy, Craig; Carvalho, Maria da Gloria S.; Mitchell, Audrey; Bjork, Adam; Regan, Joanna J.

2014-01-01

Rocky Mountain spotted fever, a tick-borne disease caused by Rickettsia rickettsii, is challenging to diagnose and rapidly fatal if not treated. We describe a decedent who was co-infected with group A β-hemolytic streptococcus and R. rickettsii. Fatal cases of Rocky Mountain spotted fever may be underreported because they present as difficult to diagnose co-infections. PMID:25331804

Infection of the whitefly Bemisia tabaci with Rickettsia spp. alters its interactions with Tomato yellow leaf curl virus

Science.gov (United States)

Numerous animal and plant viruses are transmitted by arthropod vectors in a persistent, circulative manner. Tomato yellow leaf curl virus (TYLCV) is transmitted by the sweet potato whitefly Bemisia tabaci. Here we report that infection with Rickettsia spp., a facultative endosymbiont of whiteflies...

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

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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.

Tularemia con afectación faríngea y ganglionar cervical

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María Martín-Bailón

2018-05-01

Full Text Available Introducción: La tularemia es una zoonosis producida por la bacteria Francisella tularensis, la cual se encuentra principalmente en conejos y otros animales y a veces libre en el suelo o en aguas contaminadas. Se trasmite fundamentalmente a través de la picadura de garrapata aunque también puede adquirirse por contacto directo con productos animales, agua o alimentos contaminados o por aerosolización de las bacterias. En áreas geográficas con alto porcentaje de población rural en contacto con animales sigue siendo una enfermedad a tener en cuenta en el diagnóstico diferencial de síndromes adenopáticos.Caso clínico: Varón de 45 años sin antecedentes de interés que acude a Urgencias por odinofagia derecha sin fiebre y aparición de tumoración laterocervical derecha. En la exploración se objetiva ulceración y varias aftas a nivel de amígdala derecha, así como adenopatía cervical en nivel II derecho de unos 5 cm de tamaño; analítica de sangre dentro de la normalidad. Se instaura tratamiento con amoxicilina-clavulánico y antiinflamatorios, pero a los pocos días el paciente consulta de nuevo por ausencia de mejoría. Se solicita TC de cuello con contraste que muestra adenopatía abscesificada en área II derecha de 3 cm de tamaño. Serología para tularemia positiva. Se instaura tratamiento con Levofloxacino intravenoso durante 5 días y posteriormente oral durante 10 días más, con buena respuesta. Revisión del paciente a los 3 meses, estando asintomático, con negativización de la serología y desaparición de la adenopatía cervical.Discusión: Se distinguen siete formas clínicas de tularemia, siendo la ulceroganglionar responsable del 75% de los casos: consiste en  la aparición de una lesión típica cutánea o mucosa  y adenopatías mayores de 1 cm. Es frecuente la abscesificación de estas adenopatías, pudiendo fistulizar al exterior de forma espontánea. En un 25 % de los pacientes aparece una forma orofar

Tifus exantemático en las provincias de Quispicanchis, Paucartambo y Acomayo del departamento del Cusco, Perú*

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Antonia Calvo Cajigas

2003-07-01

Full Text Available Objetivo: Determinar la infección por Rickettsia mediante la detección de anticuerpos o de ácido desoxiribonucleico (ADN en pacientes notificados como casos probables de tifus exantemático de las provincias de Quispicanchis, Acomayo y Paucartambo, Cusco, Perú. Materiales y métodos: En este estudio descriptivo, realizado entre junio y diciembre de 2001, se detectó la infección por Rickettsia en muestras de sangre venosa de pacientes mayores de 5 años con diagnóstico probable de tifus, mediante la determinación de anticuerpos por el método de la inmunoperoxidasa y de ADN por la prueba de PCR tifus (pacientes con temperatura ≥ 38ºC con un tiempo de enfermedad menor de 5 días. Resultados: En 23 (33,8% pacientes de 68 casos probables notificados se demostró la presencia de anticuerpos anti Rickettsia: 13 (19,1% con un título de 1/64 y 10 (14,7% con un título de 1/128. Los pacientes mayores de 14 años presentaron mayor positividad a la prueba de inmunoperoxidasa que aquellos ≤ 14 años (p = 0,008, OR = 7,24. Ningún PCR realizado (26 resultó positivo. Conclusiones: Mediante la prueba de inmunoperoxidasa se logró demostrar la infección por Rickettsia en casos probables de tifus exantemático en las localidades estudiadas.

Hidradenocarcinoma do Escroto com Metastização Ganglionar

OpenAIRE

Simões, MI; Marcão, I; Toscano, M; Borges, L

2018-01-01

O hidradenocarcinoma é uma neoplasia rara das células écrinas das glândulas sudoríparas, geralmente assintomática e de crescimento lento, com maior incidência entre os 50 e os 80 anos, atingindo ambos os sexos e com localização preferencial nas regiões palmar, plantar, frontal, axilar e nuca. Tem um comportamento agressivo, com alta taxa de recorrência local e metastização à distância, associando-se a mau prognóstico. Apresentamos um caso raro de hidradenocarcinoma do escroto manifestado por ...

Genomic Diversification in Strains of Rickettsia felis Isolated from Different Arthropods

Science.gov (United States)

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

Prevalence of infection with Rickettsia helvetica in Ixodes ricinus ticks feeding on non-rickettsiemic rodent hosts in sylvatic habitats of west-central Poland.

Science.gov (United States)

Biernat, Beata; Stańczak, Joanna; Michalik, Jerzy; Sikora, Bożena; Wierzbicka, Anna

2016-02-01

Ixodes ricinus is the most prevalent and widely distributed tick species in European countries and plays a principal role in transmission of a wide range of microbial pathogens. It is also a main vector and reservoir of Rickettsia spp. of the spotted fever group with the infection level ranging in Poland from 1.3% to 11.4%. Nevertheless, little research has been conducted so far to identify reservoir hosts for these pathogens. A survey was undertaken to investigate the presence of Rickettsia spp. in wild small rodents and detached I. ricinus. Rodents, Apodemus flavicollis mice and Myodes glareolus voles were captured in typically sylvatic habitats of west-central Poland. Blood samples and collected ticks were analyzed by conventional, semi-nested and nested PCRs. Rickettsial species were determined by sequence analysis of obtained fragments of gltA and 16S rRNA genes. A total of 2339 immature I. ricinus (mostly larvae) were collected from 158 animals. Proportion of hosts carrying ticks was 84%, being higher for A. flavicollis than for M. glareolus. Rickettsia helvetica, the only species identified, was detected in 8% of 12 nymphs and in at least 10.7% (MIR) of 804 larvae investigated. Prevalence of infected ticks on both rodent species was comparable (10.8 vs. 9%). None of blood samples tested was positive for Rickettsia spp. The results showed that in sylvatic habitats the level of infestation with larval I. ricinus was higher in A. flavicollis mice in comparison with M. glareolus voles. They show that R. helvetica frequently occurred in ticks feeding on rodents. Positive immature ticks were collected from non-rickettsiemic hosts what might suggest a vertical route of their infection (transovarial and/or transstadial) or a very short-lasting rickettsiemia in rodents. A natural vertebrate reservoir host for R. helvetica remains to be determined. Copyright © 2015 Elsevier GmbH. All rights reserved.

Circulação de Rickettsias do Grupo da Febre Maculosa em cães no entorno de Unidades de Conservação Federais do estado do Rio de Janeiro: evidência sorológica e fatores associados

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Sabrina D.E. Campos

Full Text Available RESUMO: Doenças causadas por rickettsias tem ampla distribuição geográfica e estão associadas a artrópodes hematófagos. Rickettsia rickettsii é espécie mais patogênica do Grupo da Febre Maculosa (GFM e responsável pela Febre Maculosa Brasileira. No sudeste do país a doença é endêmica e inquéritos sorológicos tem demonstrado presença de anticorpos para antígenos do GFM em cães, reforçando a participação do cão como sentinela. Os principais vetores são carrapatos do gênero Amblyomma, cujos hospedeiros são, muitas vezes, animais de vida silvestre. Assim, objetivou-se avaliar a circulação de rickettsias do GFM no entorno de Unidades de Conservação (UC no Rio de Janeiro por meio da Imunofluorescência Indireta em cães, além de determinar os fatores associados. Amostras de soro de 155 cães foram testadas, sendo 16,1% dos animais sororreagentes pelo menos a um dos antígenos testados. Houve associação entre a sororreatividade dos cães e o acesso à mata; falta de assistência médico-veterinária; falta de medidas contra carrapatos; e renda familiar do responsável de até dois salários mínimos. Cães com este perfil apresentaram maior chance de serem expostos aos agentes do GFM. De acordo com o modelo de regressão logística, não frequentar áreas de mata foi considerado um fator de proteção para o cão, juntamente com possuir acompanhamento médico-veterinário e receber medidas contra carrapatos. Concluiu-se que patógenos do GFM circulam no entorno das UC estudadas, sendo possível que R. rickettsii e R. parkeri infectem cães, uma vez que os animais demonstraram exposição aos dois agentes. Ressalta-se a participação do veterinário e a adoção de medidas de combate a carrapatos como ferramentas na prevenção da infecção rickettsial.

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

International Nuclear Information System (INIS)

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

2011-01-01

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

First report of Rickettsia raoultii and R. slovaca in Melophagus ovinus, the sheep ked

OpenAIRE

Liu, Dan; Wang, Yuan-Zhi; Zhang, Huan; Liu, Zhi-Qiang; Wureli, Ha-zi; Wang, Shi-Wei; Tu, Chang-Chun; Chen, Chuang-Fu

2016-01-01

Background Melophagus ovinus (Diptera: Hippoboscidae), a hematophagous ectoparasite, is mainly found in Europe, Northwestern Africa, and Asia. This wingless fly infests sheep, rabbits, and red foxes, and causes inflammation, wool loss and skin damage. Furthermore, this parasite has been shown to transmit diseases, and plays a role as a vector. Herein, we investigated the presence of various Rickettsia species in M. ovinus. Methods In this study, a total of 95 sheep keds were collected in Kuqa...

Revista de tesis de la Facultad de Medicina de Bogotá

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Facultad de Medicina Revista

1943-05-01

Full Text Available Abscesos del pulmón. Tesis de grado, declarada Meritoria. 1942. Por Francisco Torres León / Banda de coagulación de Weltmann. Tesis de grado, declarada Meritoria. 1942.-Por Alfredo Artunduaga Paredes / Higiene e inspección de las carnes. Tesis de grado. 1942. - Por Baldomero Cleves Ortiz / Variaciones de la glucemia en el periodo postoperatorio. Tesis de grado. 1942. - Por Enrique Cortázar García / Contribución al estudio de la reserva alcalina en los niños de Bogotá. Tesis de grado. 1942. - Por Alfonso Gómez Tavera / La paralisis infantil y su tratamiento. Tesis de grado. 1942. - Por Carlos Arturo Arango / Observaciones sobre la puncion ganglionar en la sifills reciente. Tesis de grado. 1942. - Por Gustavo Ramírez C.

Rickettsial spotted fever in capoeirão Village, Itabira, Minas Gerais, Brazil Rickettsiose do grupo da febre maculosa na Vila de Capoeirão, Itabira, Minas Gerais, Brasil

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Manoella Campostrini Barreto Vianna

2008-10-01

Full Text Available The present study investigated the infection by spotted fever rickettsia in an endemic area for Brazilian spotted fever (BSF; caused by Rickettsia rickettsii in Minas Gerais State, Brazil. Human, canine and equine sera samples, and Amblyomma cajennense adult ticks collected in a rural area of Itabira City, Minas Gerais State were tested for rickettsial infection. Through Immunofluorescence Assay (IFA we demonstrated the presence of antibodies anti-R. rickettsii in 8.2%, 81.3% and 100% of the human, canine and equine sera, respectively. None of the 356 tick specimens analyzed were positive for Rickettsia by the hemolymph test or Polymerase Chain Reaction technique (PCR for the htrA and the gltA genes. Our serological results on horses and dogs (sentinels for BSF appoint for the circulation of a SFG Rickettsia in the study area, however in a very low infection rate among the A. cajennense tick population.O presente estudo investigou a infecção por rickéttsias do grupo da febre maculosa (GFM em área endêmica para febre maculosa brasileira (FMB; causada por Rickettsia rickettsii no Estado de Minas Gerais, Brasil. Amostras de soros de humanos, cães e eqüídeos, e carrapatos Amblyomma cajennense adultos colhidos em um povoado rural em Itabira, Minas Gerais foram testados para infecção por Rickettsia. Pela Reação de Imunofluorescência Indireta (RIFI foram detectados anticorpos anti-R. rickettsii em 8,2% dos soros humanos, 81,3% dos cães e em 100% dos eqüídeos. Nenhum dos 356 carrapatos se mostrou positivo para Rickettsia no teste de hemolinfa e na reação em cadeia pela polimerase (PCR objetivando amplificar fragmentos de DNA dos genes htrA and the gltA. Os resultados sorológicos em eqüinos e cães (sentinelas para FMB apontam para a circulação de uma rickéttsia do GFM na área do estudo, porém, numa freqüência de infecção muito baixa na população do carrapato A. cajennense.

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

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Maurício Macedo

2007-12-01

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

Human prevalence of the spotted fever group (SFG) rickettsiae in endemic zones of Northwestern Colombia.

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Londoño, Andrés F; Acevedo-Gutiérrez, Leidy Y; Marín, Diana; Contreras, Verónica; Díaz, Francisco J; Valbuena, Gustavo; Labruna, Marcelo B; Hidalgo, Marylin; Arboleda, Margarita; Mattar, Salim; Solari, Sergio; Rodas, Juan D

2017-06-01

In February 2006, an outbreak of human rickettsiosis occurred in the municipality of Necoclí Colombia, with 35% of lethality. This episode was, followed by two more, one in the municipality of Los Cordobas in 2007 with a 54% of lethality and the other one in the municipality of Turbo in 2008 with 27% of lethality. The aim of this study was to perform serological tests in healthy persons to determine the seroprevalence of antibodies against spotted fever group (SFG) rickettsiae and develop a survey to study some infection risk-related factors. A cross-sectional study was performed in 2011 and 2012. A blood sample and survey of associated factors was performed in healthy persons. A prevalence of 32%-41% was found in healthy people. From the multivariate analysis, we found that people living more than 16 years in these sites had a 79% higher risk of being seropositive and a 46% higher risk when they reported having birds in their houses if the variable of having a horse was included in the model. In conclusion, this study shows endemicity of at least one spotted fever group Rickettsia in the study zone. Copyright © 2017 Elsevier GmbH. All rights reserved.

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

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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.

Tick-borne zoonotic pathogens in ticks feeding on the common nightingale including a novel strain of Rickettsia sp

Czech Academy of Sciences Publication Activity Database

Dubská, L.; Literák, I.; Kverek, P.; Roubalová, Eva; Kocianova, E.; Taragelova, V.

2012-01-01

Roč. 3, č. 4 (2012), s. 265-268 ISSN 1877-959X Institutional support: RVO:60077344 Keywords : tick * Ixodes ricinus * Borrelia garinii * Anaplasma phagocytophilum * Rickettsia helvetica * Babesia sp. EU1 * Common nightingale Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.353, year: 2012 http://www.sciencedirect.com/science/article/pii/S1877959X12000556

Tifus

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García-Acosta, J; Aguilar-García, CR; Aguilar-Arce, IE

2017-01-01

Resumen El género Rickettsia está compuesto por dos grupos definidos antigenicamente: el grupo tifus, que incluye a Rickettsiaprowazekii, causante del tifus epidémico o exantemático, y a R. typhi, causante del tifus murino o endémico; el otro grupo es el de las fiebres manchadas. El género Rickettsia está constituido por diferentes especies de bacterias gramnegativas; a su vez, forma parte de la familia Rickettsiaceae (junto a Coxiella, Ehrlichia y Bartonella). Todas las especies del género t...

Case report: Co-infection of Rickettsia rickettsii and Streptococcus pyogenes: is fatal Rocky Mountain spotted fever underdiagnosed?

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Raczniak, Gregory A; Kato, Cecilia; Chung, Ida H; Austin, Amy; McQuiston, Jennifer H; Weis, Erica; Levy, Craig; Carvalho, Maria da Gloria S; Mitchell, Audrey; Bjork, Adam; Regan, Joanna J

2014-12-01

Rocky Mountain spotted fever, a tick-borne disease caused by Rickettsia rickettsii, is challenging to diagnose and rapidly fatal if not treated. We describe a decedent who was co-infected with group A β-hemolytic streptococcus and R. rickettsii. Fatal cases of Rocky Mountain spotted fever may be underreported because they present as difficult to diagnose co-infections. © The American Society of Tropical Medicine and Hygiene.

Fatal Brazilian spotless fever caused by Rickettsia rickettsii in a dark-skinned patient

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Alexsandra Rodrigues de Mendonça Favacho

2011-06-01

Full Text Available Brazilian spotted fever (BSF is the most important and frequent rickettsial disease in Brazil. A fatal case of BSF is reported in a 32-year-old black man, who died of irreversible shock after five days of fever, severe headache and abdominal pain with no rash. Spleen, kidney and heart samples collected at autopsy were positive for Rickettsia rickettsii by PCR and sequencing. The authors emphasize the need for a high index of diagnostic suspicion for spotted fever in black patients. Absence of a skin rash should not dissuade clinicians from considering the possibility of BSF and initiating empirical therapy.

Detection of Rickettsia and Ehrlichia spp. in Ticks Associated with Exotic Reptiles and Amphibians Imported into Japan.

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Andoh, Masako; Sakata, Akiko; Takano, Ai; Kawabata, Hiroki; Fujita, Hiromi; Une, Yumi; Goka, Koichi; Kishimoto, Toshio; Ando, Shuji

2015-01-01

One of the major routes of transmission of rickettsial and ehrlichial diseases is via ticks that infest numerous host species, including humans. Besides mammals, reptiles and amphibians also carry ticks that may harbor Rickettsia and Ehrlichia strains that are pathogenic to humans. Furthermore, reptiles and amphibians are exempt from quarantine in Japan, thus facilitating the entry of parasites and pathogens to the country through import. Accordingly, in the current study, we examined the presence of Rickettsia and Ehrlichia spp. genes in ticks associated with reptiles and amphibians originating from outside Japan. Ninety-three ticks representing nine tick species (genera Amblyomma and Hyalomma) were isolated from at least 28 animals spanning 10 species and originating from 12 countries (Ghana, Jordan, Madagascar, Panama, Russia, Sri Lanka, Sudan, Suriname, Tanzania, Togo, Uzbekistan, and Zambia). None of the nine tick species are indigenous in Japan. The genes encoding the common rickettsial 17-kDa antigen, citrate synthase (gltA), and outer membrane protein A (ompA) were positively detected in 45.2% (42/93), 40.9% (38/93), and 23.7% (22/93) of the ticks, respectively, by polymerase chain reaction (PCR). The genes encoding ehrlichial heat shock protein (groEL) and major outer membrane protein (omp-1) were PCR-positive in 7.5% (7/93) and 2.2% (2/93) of the ticks, respectively. The p44 gene, which encodes the Anaplasma outer membrane protein, was not detected. Phylogenetic analysis showed that several of the rickettsial and ehrlichial sequences isolated in this study were highly similar to human pathogen genes, including agents not previously detected in Japan. These data demonstrate the global transportation of pathogenic Rickettsia and Ehrlichia through reptile- and amphibian-associated ticks. These imported animals have potential to transfer pathogens into human life. These results highlight the need to control the international transportation of known and

Detection of Rickettsia and Ehrlichia spp. in Ticks Associated with Exotic Reptiles and Amphibians Imported into Japan.

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Masako Andoh

Full Text Available One of the major routes of transmission of rickettsial and ehrlichial diseases is via ticks that infest numerous host species, including humans. Besides mammals, reptiles and amphibians also carry ticks that may harbor Rickettsia and Ehrlichia strains that are pathogenic to humans. Furthermore, reptiles and amphibians are exempt from quarantine in Japan, thus facilitating the entry of parasites and pathogens to the country through import. Accordingly, in the current study, we examined the presence of Rickettsia and Ehrlichia spp. genes in ticks associated with reptiles and amphibians originating from outside Japan. Ninety-three ticks representing nine tick species (genera Amblyomma and Hyalomma were isolated from at least 28 animals spanning 10 species and originating from 12 countries (Ghana, Jordan, Madagascar, Panama, Russia, Sri Lanka, Sudan, Suriname, Tanzania, Togo, Uzbekistan, and Zambia. None of the nine tick species are indigenous in Japan. The genes encoding the common rickettsial 17-kDa antigen, citrate synthase (gltA, and outer membrane protein A (ompA were positively detected in 45.2% (42/93, 40.9% (38/93, and 23.7% (22/93 of the ticks, respectively, by polymerase chain reaction (PCR. The genes encoding ehrlichial heat shock protein (groEL and major outer membrane protein (omp-1 were PCR-positive in 7.5% (7/93 and 2.2% (2/93 of the ticks, respectively. The p44 gene, which encodes the Anaplasma outer membrane protein, was not detected. Phylogenetic analysis showed that several of the rickettsial and ehrlichial sequences isolated in this study were highly similar to human pathogen genes, including agents not previously detected in Japan. These data demonstrate the global transportation of pathogenic Rickettsia and Ehrlichia through reptile- and amphibian-associated ticks. These imported animals have potential to transfer pathogens into human life. These results highlight the need to control the international transportation of known

Characterization of Spotted Fever Group Rickettsiae in Flea and Tick Specimens From Northern Peru

Science.gov (United States)

2004-11-01

boliviensis 3 (18.7) 1 (6.2) Ixodes pararicinus 2 (12.5) 0 Flea speciesb Adoratopsilla intermedia 2 (3.4) 0 Ctenocephalides felis 33 (55.9) 2 (3.4...analysis of a genus-common rickettsial antigen gene. J. Bacteriol. 171:5199–5201. 3. Azad, A. F., S. Radulovic, J. A. Higgins , B. H. Noden, and J. M...Y. Acad. Sci. 990:57–61. 21. Hackstadt, T. 1996. The biology of rickettsiae. Infect. Agents Dis. 5:127–143. 22. Higgins , J. A., S. Radulovic, M. E

Development and Validation of an Improved PCR Method Using the 23S-5S Intergenic Spacer for Detection of Rickettsiae in Dermacentor variabilis Ticks and Tissue Samples from Humans and Laboratory Animals.

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Kakumanu, Madhavi L; Ponnusamy, Loganathan; Sutton, Haley T; Meshnick, Steven R; Nicholson, William L; Apperson, Charles S

2016-04-01

A novel nested PCR assay was developed to detectRickettsiaspp. in ticks and tissue samples from humans and laboratory animals. Primers were designed for the nested run to amplify a variable region of the 23S-5S intergenic spacer (IGS) ofRickettsiaspp. The newly designed primers were evaluated using genomic DNA from 11Rickettsiaspecies belonging to the spotted fever, typhus, and ancestral groups and, in parallel, compared to otherRickettsia-specific PCR targets (ompA,gltA, and the 17-kDa protein gene). The new 23S-5S IGS nested PCR assay amplified all 11Rickettsiaspp., but the assays employing other PCR targets did not. The novel nested assay was sensitive enough to detect one copy of a cloned 23S-5S IGS fragment from "CandidatusRickettsia amblyommii." Subsequently, the detection efficiency of the 23S-5S IGS nested assay was compared to those of the other three assays using genomic DNA extracted from 40 adultDermacentor variabilisticks. The nested 23S-5S IGS assay detectedRickettsiaDNA in 45% of the ticks, while the amplification rates of the other three assays ranged between 5 and 20%. The novel PCR assay was validated using clinical samples from humans and laboratory animals that were known to be infected with pathogenic species ofRickettsia The nested 23S-5S IGS PCR assay was coupled with reverse line blot hybridization with species-specific probes for high-throughput detection and simultaneous identification of the species ofRickettsiain the ticks. "CandidatusRickettsia amblyommii,"R. montanensis,R. felis, andR. belliiwere frequently identified species, along with some potentially novelRickettsiastrains that were closely related toR. belliiandR. conorii. Copyright © 2016 Kakumanu et al.

Diversity of Babesia and Rickettsia species in questing Ixodes ricinus: a longitudinal study in urban, pasture, and natural habitats.

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Overzier, Evelyn; Pfister, Kurt; Thiel, Claudia; Herb, Ingrid; Mahling, Monia; Silaghi, Cornelia

2013-08-01

In a previous study, our group investigated the Babesia spp. prevalence in questing Ixodes ricinus ticks from nine city parks in South Germany in the years 2009 and 2010. We showed predominant prevalence of B. venatorum (in previous literature also known as Babesia sp. EU1), especially in those parks in a more natural condition and with occurrence of large wild animals, such as roe deer. To obtain longitudinal data and to broaden the knowledge about this pathogen, further investigations were carried out in 2011 and 2012 in four of those city parks. Two additional habitat types were chosen for comparison of prevalence data and species analysis focusing on occurrence of potential reservoir hosts. A total of 10,303 questing I. ricinus were collected in four city parks, a pasture, and a natural area in Bavaria, and a representative number of samples were investigated for prevalence of DNA of Babesia spp. (n=4381) and Rickettsia spp. (n=2186) by PCR. In the natural and pasture area, a significantly higher Babesia spp. prevalence compared to the urban area was detected. The natural area revealed sequences of B. microti, B. venatorum, and B. capreoli. In the pasture and urban habitat, predominantly B. venatorum was found, whereas B. capreoli was less frequent and only one B. microti-infected tick was found. All B. microti sequences were 100% identical to the zoonotic Jena/Germany strain. For Rickettsia spp., the significantly highest prevalence was also detected in the natural and pasture areas, whereas lower prevalence was found in the urban area. Sequence analysis revealed R. helvetica (98%) and R. monacensis (2%). Prevalence rates and occurrence of Babesia spp. and Rickettsia spp. differed in urban, pasture and natural sites, most likely depending on the habitat structure (natural or cultivated) and therefore on the appearance and availability of reservoir hosts like roe deer or small mammals.

Novel Rickettsia raoultii strain isolated and propagated from Austrian Dermacentor reticulatus ticks

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Michiel Wijnveld

2016-11-01

Full Text Available Abstract Background Continuous culture of tick cell lines has proven a valuable asset in isolating and propagating several different vector-borne pathogens, making it possible to study these microorganisms under laboratory conditions and develop serological tests to benefit public health. We describe a method for effective, cost- and labor-efficient isolation and propagation of Rickettsia raoultii using generally available laboratory equipment and Rhipicephalus microplus cells, further demonstrating the usefulness of continuous tick cell lines. R. raoultii is one of the causative agents of tick-borne lymphadenopathy (TIBOLA and is, together with its vector Dermacentor reticulatus, emerging in novel regions of Europe, giving rise to an increased threat to general public health. Methods Dermacentor reticulatus ticks were collected in the Donau-Auen (Lobau national park in Vienna, Austria. The hemolymph of ten collected ticks was screened by PCR-reverse line blot for the presence of rickettsial DNA. A single tick tested positive for R. raoultii DNA and was used to infect Rhipicephalus microplus BME/CTVM2 cells. Results Sixty-five days after infection of the tick-cell line with an extract from a R. raoultii-infected tick, we observed intracellular bacteria in the cultured cells. On the basis of microscopy we suspected that the intracellular bacteria were a species of Rickettsia; this was confirmed by several PCRs targeting different genes. Subsequent sequencing showed 99–100 % identity with R. raoultii. Cryopreservation and resuscitation of R. raoultii was successful. After 28 days identical intracellular bacteria were microscopically observed. Conclusions R. raoultii was successfully isolated and propagated from D. reticulatus ticks using R. microplus BME/CTVM2 cells. The isolated strain shows significant molecular variation compared to currently known sequences. Furthermore we show for the first time the successful cryopreservation and

Novel Rickettsia raoultii strain isolated and propagated from Austrian Dermacentor reticulatus ticks.

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Wijnveld, Michiel; Schötta, Anna-Margarita; Pintér, Adriano; Stockinger, Hannes; Stanek, Gerold

2016-11-03

Continuous culture of tick cell lines has proven a valuable asset in isolating and propagating several different vector-borne pathogens, making it possible to study these microorganisms under laboratory conditions and develop serological tests to benefit public health. We describe a method for effective, cost- and labor-efficient isolation and propagation of Rickettsia raoultii using generally available laboratory equipment and Rhipicephalus microplus cells, further demonstrating the usefulness of continuous tick cell lines. R. raoultii is one of the causative agents of tick-borne lymphadenopathy (TIBOLA) and is, together with its vector Dermacentor reticulatus, emerging in novel regions of Europe, giving rise to an increased threat to general public health. Dermacentor reticulatus ticks were collected in the Donau-Auen (Lobau) national park in Vienna, Austria. The hemolymph of ten collected ticks was screened by PCR-reverse line blot for the presence of rickettsial DNA. A single tick tested positive for R. raoultii DNA and was used to infect Rhipicephalus microplus BME/CTVM2 cells. Sixty-five days after infection of the tick-cell line with an extract from a R. raoultii-infected tick, we observed intracellular bacteria in the cultured cells. On the basis of microscopy we suspected that the intracellular bacteria were a species of Rickettsia; this was confirmed by several PCRs targeting different genes. Subsequent sequencing showed 99-100 % identity with R. raoultii. Cryopreservation and resuscitation of R. raoultii was successful. After 28 days identical intracellular bacteria were microscopically observed. R. raoultii was successfully isolated and propagated from D. reticulatus ticks using R. microplus BME/CTVM2 cells. The isolated strain shows significant molecular variation compared to currently known sequences. Furthermore we show for the first time the successful cryopreservation and resuscitation of R. raoultii.

Distribution of rats infected with Rickettsia tsutsugamushi (scrub typhus) in an edge habitat.

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Muul, I; Chai, K S

1978-12-01

No focalization of rats (Rattus tiomanicus and R. argentiventer) infected with Rickettsia tsutsugamushi could be discerned over a 500 m trapping transect at the border between a forest and lalang grass (Imperata cylindrica). R. tiomanicus appeared to occupy 250 m of the transect on the average and had periods during which infections were observed which averaged 97 days. Calulations indicated that more than 50% of individuals become infected over their life-time. The high rate of infection in this and other areas described in earlier publications and the habits of the rats suggest that infected mites are densely and widely dispersed in the areas studied in Malaysia.

Por trás de adenopatias generalizadas

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Liliana Branco

2016-06-01

Full Text Available Introdução: As adenopatias são frequentes na população pediátrica. Geralmente são secundárias a processos benignos e auto-limitados, mas podem associar-se a situações de maior gravidade. Quando ocorre envolvimento de duas ou mais regiões ganglionares não contíguas é classificada como generalizada, sendo a doença sistémica a causa mais comum. Caso clínico: Adolescente do sexo masculino, 16 anos de idade, admitido no serviço de urgência (SU por tumefação axilar à esquerda com 4 dias de evolução. Sem sintomas sistémicos associados. Negava conviventes doentes ou viagens recentes. De salientar apenas o contato com animais (cão e gato. Ao exame objetivo apresentava adenomegalias na região cervical (bilaterais com cerca de 2 cm de maior diâmetro à esquerda, supraclavicular (à esquerda com cerca de 1 cm de maior diâmetro e axilar (bilaterais com cerca de 1,5 cm de maior diâmetro à esquerda, de consistência elástica, bordos regulares, indolores à palpação e não aderentes aos planos superficiais e profundos. O estudo analítico e a radiografia torácica não revelaram alterações de relevo. Efetuou tomografia computorizada (TC tóraco-abdominopélvica que confirmou a presença de adenopatias generalizadas nomeadamente axilares, mediastínicas, retroperitoneais e mesentéricas. De salientar marcadores víricos negativos. O estudo serológico revelou tratar-se de uma infeção aguda portoxoplasmose, pela presença de IgG e de IgM positivas (>250 UI/L e >10.000 respetivamente. Em consulta de seguimento, foi documentado o decréscimo da IgM (7,66 Index tendo-se verificado concomitantemente uma resolução progressiva e espontânea da sintomatologia. Conclusão: As adenopatias generalizadas estão associadas a inúmeras etiologias constituindo um desafio diagnóstico. A toxoplasmose é uma infeção causada por um parasita intracelular, o Toxoplasma gondii (T.gondii, e a serologia é o teste mais utilizado para

Tick-borne diseases in North Carolina: is "Rickettsia amblyommii" a possible cause of rickettsiosis reported as Rocky Mountain spotted fever?

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Apperson, Charles S; Engber, Barry; Nicholson, William L; Mead, Daniel G; Engel, Jeffrey; Yabsley, Michael J; Dail, Kathy; Johnson, Joey; Watson, D Wesley

2008-10-01

Cases of Rocky Mountain spotted fever (RMSF) in North Carolina have escalated markedly since 2000. In 2005, we identified a county in the Piedmont region with high case numbers of RMSF. We collected ticks and examined them for bacterial pathogens using molecular methods to determine if a novel tick vector or spotted fever group rickettsiae (SFGR) might be emerging. Amblyomma americanum, the lone star tick, comprised 99.6% of 6,502 specimens collected in suburban landscapes. In contrast, Dermacentor variabilis, the American dog tick, a principal vector of Rickettsia rickettsii, comprised < 1% of the ticks collected. Eleven of 25 lone star tick pools tested were infected with "Rickettsia amblyommii," an informally named SFGR. Sera from patients from the same county who were presumptively diagnosed by local physicians with a tick-borne illness were tested by an indirect immunofluorescence antibody (IFA) assay to confirm clinical diagnoses. Three of six patients classified as probable RMSF cases demonstrated a fourfold or greater rise in IgG class antibody titers between paired acute and convalescent sera to "R. amblyommii" antigens, but not to R. rickettsii antigens. White-tailed deer, Odocoileus virginianus, are preferred hosts of lone star ticks. Blood samples collected from hunter-killed deer from the same county were tested by IFA test for antibodies to Ehrlichia chaffeensis and "R. amblyommii." Twenty-eight (87%) of 32 deer were positive for antibodies to E. chaffeensis, but only 1 (3%) of the deer exhibited antibodies to "R. amblyommii," suggesting that deer are not the source of "R. amblyommii" infection for lone star ticks. We propose that some cases of rickettsiosis reported as RMSF may have been caused by "R. amblyommii" transmitted through the bite of A. americanum.

Detection of Ehrlichia spp., Anaplasma spp., Rickettsia spp., and other eubacteria in ticks from the Thai-Myanmar border and Vietnam.

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Parola, Philippe; Cornet, Jean-Paul; Sanogo, Yibayiri Osée; Miller, R Scott; Thien, Huynh Van; Gonzalez, Jean-Paul; Raoult, Didier; Telford III, Sam R; Wongsrichanalai, Chansuda

2003-04-01

A total of 650 ticks, including 13 species from five genera, were collected from animals, from people, or by flagging of the vegetation at sites on the Thai-Myanmar border and in Vietnam. They were tested by PCR to detect DNA of bacteria of the order RICKETTSIALES: Three Anaplasma spp. were detected in ticks collected in Thailand, including (i) Anaplasma sp. strain AnDa465, which was considered a genotype of Anaplasma platys (formerly Ehrlichia platys) and which was obtained from Dermacentor auratus ticks collected from dogs; (ii) Anaplasma sp. strain AnAj360, which was obtained from Amblyomma javanense ticks collected on a pangolin; and (iii) Anaplasma sp. strain AnHl446, which was closely related to Anaplasma bovis and which was detected in Haemaphysalis lagrangei ticks collected from a bear. Three Ehrlichia spp. were identified, including (i) Ehrlichia sp. strain EBm52, which was obtained from Boophilus microplus ticks collected from cattle from Thailand; (ii) Ehrlichia sp. strain EHh324, which was closely related to Ehrlichia chaffeensis and which was detected in Haemaphysalis hystricis ticks collected from wild pigs in Vietnam; and (iii) Ehrlichia sp. strain EHh317, which was closely related to Ehrlichia sp. strain EBm52 and which was also detected in H. hystricis ticks collected from wild pigs in Vietnam. Two Rickettsia spp. were detected in Thailand, including (i) Rickettsia sp. strain RDla420, which was detected in Dermacentor auratus ticks collected from a bear, and (ii) Rickettsia sp. strain RDla440, which was identified from two pools of Dermacentor larvae collected from a wild pig nest. Finally, two bacteria named Eubacterium sp. strain Hw124 and Eubacterium sp. strain Hw191 were identified in Haemaphysalis wellingtoni ticks collected from chicken in Thailand; these strains could belong to a new group of bacteria.

Detection of Rickettsia helvetica and Candidatus R. tarasevichiae DNA in Ixodes persulcatus ticks collected in Northeastern European Russia (Komi Republic).

Science.gov (United States)

Kartashov, Mikhail Yu; Glushkova, Ludmila I; Mikryukova, Tamara P; Korabelnikov, Igor V; Egorova, Yulia I; Tupota, Natalia L; Protopopova, Elena V; Konovalova, Svetlana N; Ternovoi, Vladimir A; Loktev, Valery B

2017-06-01

The number of tick-borne infections in the northern European regions of Russia has increased considerably in the last years. In the present study, 676 unfed adult Ixodes persulcatus ticks were collected in the Komi Republic from 2011 to 2013 to study tick-borne rickettsioses. Rickettsia spp. DNA was detected by PCR in 51 (7.6%) ticks. The nucleotide sequence analysis of gltA fragments (765bp) from 51 ticks indicated that 60.8% and 39.2% of the ticks were infected with Rickettsia helvetica and Candidatus R. tarasevichiae, respectively. The gltA fragments showed 100% identity with those of Candidatus R. tarasevichiae previously discovered in Siberia and China, whereas R. helvetica showed 99.9% sequence identity with European isolates. The ompB had 8 nucleotide substitutions, 6 of which resulted in amino acid substitutions. In the sca9 gene, 3 nucleotide substitutions were detected, and only one resulted in amino acid substitution. The smpA, ompW, and β-lactamase genes of R. helvetica also showed a high level of sequence identity. Copyright © 2017 Elsevier GmbH. All rights reserved.

Prevalencia y detección por PCR anidada de Anaplasma marginale en bovinos y garrapatas en la zona central del Litoral ecuatoriano

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Ariel Escobar Troya

2015-09-01

Full Text Available La bacteria que provoca la anaplasmosis en bovinos se conoce como Anaplasma marginale, es potencialmente transmitida de forma biológica por garrapatas, moscas y fómites o mediante sangre infectada como consecuencia del uso incorrecto de herramientas quirúrgicas. Hasta la fecha, Ecuador carece de estudios actualizados sobre procedimientos eficientes para el diagnóstico específico y, erradicación de A. marginale a través del control de estos insectos, por lo que resulta de gran importancia desarrollar e implementar trabajos relacionados con el uso de esta herramienta molecular, para la detección de la bacteria en vectores de transmisión que provocan la enfermedad en bovinos. En este trabajo, se extrajo ADN eficazmente con el método de Salting Out. Un total de 255 muestras fueron analizadas por PCR anidada, distribuidas del siguiente modo|108| Riphicephalus (Boophilus microplus, |85| bovinos, de estos el 13.46% y 85.48% dieron positivas para la rickettsia, las muestras de Amblyomma spp. |62| todas fueron negativas. El índice de concordancia Kappa |total de bovinos infestados frente a Riphicephalus (Boophilus microplus|, no fue significativo (0.28. Subsiguientemente, se determinó por χ2 (p=0.66 que la presencia o ausencia de la enfermedad es independiente del lugar de donde proviene el bovino.

Thoracic radiographic findings in dogs infected with Rickettsia rickettsii

International Nuclear Information System (INIS)

Drost, W.T.; Berry, C.R.; Breitschwerdt, E.B.; Davidson, M.G.

1997-01-01

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Experimental infection of the tick Amblyomma cajennense, Cayenne tick, with Rickettsia rickettsii, the agent of Rocky Mountain spotted fever.

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Soares, J F; Soares, H S; Barbieri, A M; Labruna, M B

2012-06-01

In the laboratory, Amblyomma cajennense (Acari: Ixodidae) (Fabricius) larvae, nymphs and adults were exposed to Rickettsia rickettsii by feeding on needle-inoculated animals, and thereafter reared on uninfected guinea pigs or rabbits. Regardless of the tick stage that acquired the infection, subsequent tick stages were shown to be infected (confirming transstadial and transovarial transmissions) and were able to transmit R. rickettsii to uninfected animals, as demonstrated by serological and molecular analyses. However, the larval, nymphal and adult stages of A. cajennense were shown to be partially refractory to R. rickettsii infection, as in all cases, only part of the ticks became infected by this agent, after being exposed to rickettsemic animals. In addition, less than 50% of the infected engorged females transmitted rickettsiae transovarially, and when they did so, only part of the offspring became infected, indicating that vertical transmission alone is not enough to maintain R. rickettsii in A. cajennense for multiple generations. Finally, the R. rickettsii-infected tick groups had lower reproductive performance than the uninfected control group. Our results indicate that A. cajennense have a low efficiency to maintain R. rickettsii for successive generations, as R. rickettsii-infection rates should decline drastically throughout the successive tick generations. © 2011 The Authors. Medical and Veterinary Entomology © 2011 The Royal Entomological Society.

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

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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 23 protein spots by electrospray ionization tandem mass spectrometry. Five (OmpA, OmpB, GroEL, GroES, and a DNA-binding protein) of the 10 proteins were previously characterized as surface proteins of R. rickettsii. Another 5 proteins (Adr1, Adr2, OmpW, Porin_4, and TolC) were first recognized as SEPs of R. rickettsii herein. The genes encoding the 5 novel SEPs were expressed in Escherichia coli cells, resulting in 5 recombinant SEPs (rSEPs), which were used to immunize mice. After challenge with viable R. rickettsii cells, the rickettsial load in the spleen, liver, or lung of mice immunized with rAdr2 and in the lungs of mice immunized with other rSEPs excluding rTolC was significantly lower than in mice that were mock-immunized with PBS. The in vitro neutralization test revealed that sera from mice immunized with rAdr1, rAdr2, or rOmpW reduced R. rickettsii adherence to and invasion of vascular endothelial cells. The immuno-electron microscopic assay clearly showed that the novel SEPs were located in the outer and/or inner membrane of R. rickettsii. Altogether, the 5 novel SEPs identified herein might be involved in the interaction of R. rickettsii with vascular endothelial cells, and all of them except TolC were protective antigens. PMID:24950252

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

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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.

Host- and microbe-related risk factors for and pathophysiology of fatal Rickettsia conorii infection in Portuguese patients.

Science.gov (United States)

Sousa, Rita de; França, Ana; Dória Nòbrega, Sónia; Belo, Adelaide; Amaro, Mario; Abreu, Tiago; Poças, José; Proença, Paula; Vaz, José; Torgal, Jorge; Bacellar, Fátima; Ismail, Nahed; Walker, David H

2008-08-15

The pathophysiologic mechanisms that determine the severity of Mediterranean spotted fever (MSF) and the host-related and microbe-related risk factors for a fatal outcome are incompletely understood. This prospective study used univariate and multivariate analyses to determine the risk factors for a fatal outcome for 140 patients with Rickettsia conorii infection admitted to 13 Portuguese hospitals during 1994-2006 with documented identification of the rickettsial strain causing their infection. A total of 71 patients (51%) were infected with the Malish strain of Rickettsia conorii, and 69 (49%) were infected with the Israeli spotted fever (ISF) strain. Patients were admitted to the intensive care unit (40 [29%]), hospitalized as routine inpatients (95[67%]), or managed as outpatients (5[4%]). Death occurred in 29 adults (21%). A fatal outcome was significantly more likely for patients infected with the ISF strain, and alcoholism was a risk factor. The pathophysiology of a fatal outcome involved significantly greater incidence of petechial rash, gastrointestinal symptoms, obtundation and/or confusion, dehydration, tachypnea, hepatomegaly, leukocytosis, coagulopathy, azotemia, hyperbilirubinemia, and elevated levels of hepatic enzymes and creatine kinase. Some, but not all, of these findings were observed more often in ISF strain-infected patients. Although fatalities and similar clinical manifestations occurred among both groups of patients, the ISF strain was more virulent than the Malish strain. Multivariate analysis revealed that acute renal failure and hyperbilirubinemia were most strongly associated with a fatal outcome.

Diseño y evaluación de microesferas biodegradables de agentes neuroprotectores para el tratamiento de patologías degenerativas que afectan al segmento posterior del ojo

OpenAIRE

Checa Casalengua, Patricia

2012-01-01

Las patologías neurodegenerativas que afectan al segmento posterior del ojo se caracterizan por ser devastadoras y comprometer la visión en un gran número de sujetos. Representan un grupo de enfermedades que cursan con un daño progresivo del nervio óptico y pérdida de fotorreceptores y células ganglionares de la retina (CGR), que sin un tratamiento continuado, pueden conducir a ceguera irreversible. Las nuevas tendencias en el tratamiento de estas enfermedades neurodegenerativas oculares e...

Enfermedad de Hirschsprung

OpenAIRE

K A Santos-Jasso

2017-01-01

Definición
La enfermedad de Hirschsprung, megacolon congénito o agangliónico, o Aganglionosis Intestinal Congénita, es una anomalía caracterizada por la ausencia congénita de células ganglionares del sistema parasimpático de los piejos intermientéricos de Auerbach, situado entre las capas musculares, circular y longitudinal, y el submucoso de Meissner; con conducción inefectiva del peristaltismo, ocasionando obstrucción funcional (24, 37, 65, 8...

Rickettsiae of the Spotted Fever group in dogs, horses and ticks: an epidemiological study in an endemic region of the State of Rio de Janeiro, Brazil

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Nathalie Costa da Cunha

2014-09-01

Full Text Available ABSTRACT. Cunha N.C., Lemos E.R.S., Rozental T., Teixeira R.C., Cordeiro M.D., Lisbôa R.S., Favacho A.R., Barreira J.D., Rezende J. & Fonseca A.H. Rickettsiae of the Spotted Fever group in dogs, horses and ticks: an epidemiological study in an endemic region of the State of Rio de Janeiro, Brazil. [Rickettsias do grupo da febre maculosa em cães, equinos e carrapatos: um estudo epidemiológico em região endêmica do estado do Rio de Janeiro, Brasil.] Revista Brasileira de Medicina Veterinária, 36(3:294-300, 2014. Departamento de Epidemiologia e Saúde Pública, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, BR 465, Km 7, Seropédica, RJ 23890-000, Brasil. E-mail: adivaldo@ufrrj.br Spotted fever is a disease of which Rickettsia rickettsii is the most pathogenic agent. Its transmission is by tick bites and the infected ticks can act as vectors, reservoirs or amplifiers. The purpose of this paper is to assess the potential of dogs and horses as sentinels for brazilian spotted fever (BSF emergence and become acquainted with the tick species in a municipal region of Resende, Rio de Janeiro State, Brazil, where five BSF cases in man were registered. Dog and horse blood samples were collected from rural and periurban properties to assess IgG anti-Rickettsia rickettsii, using the indirect immunofluorescence assay (IFA. First, an analysis was conducted to detect association between IFA results and answers obtained from a questionnaire. Afterwards, a multivariate investigation was undertaken that presented significant statistical differences. Ticks were collected directly from dogs and horses for taxonomic identification. Out of the 107 canine serum samples, 30 (28.0% were reactive, with titers varying from 1:64 to 1:4096, and 77 (72.0% were not reactive. Of 96 animals in the serum analysis of horses, 9 (9.4% were reactive, all with titers of 1:64, and 87 (90.6% were non-reactive. The tick species collected from dogs were

Fisiología de la retina II. Mensaje visual en la segunda sinapsis: células amacrinas

OpenAIRE

Urtubia Vicario, César

2005-01-01

La segunda sinapsis de la vía visual tiene lugar en la capa plexiforme interna, si bien hay muchos contactos sinápticos en la capa de las células ganglionares. Lás células amacrinas establecen sinapsis con células bipolares, entre sí, con células ganglionares, y como elemento pre y postsináptico de las células interplexiformes. Las células amacrinas modulan la respuesta directamente al actuar sobre las ganglionares o interaccionando entre sí. Esta acción, junto con la que las células horizont...

Exposure and risk factors to coxiella burnetii, spotted fever group and typhus group Rickettsiae, and Bartonella henselae among volunteer blood donors in Namibia.

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Bruce H Noden

Full Text Available The role of pathogen-mediated febrile illness in sub-Saharan Africa is receiving more attention, especially in Southern Africa where four countries (including Namibia are actively working to eliminate malaria. With a high concentration of livestock and high rates of companion animal ownership, the influence of zoonotic bacterial diseases as causes of febrile illness in Namibia remains unknown.The aim of the study was to evaluate exposure to Coxiella burnetii, spotted fever and typhus group rickettsiae, and Bartonella henselae using IFA and ELISA (IgG in serum collected from 319 volunteer blood donors identified by the Blood Transfusion Service of Namibia (NAMBTS. Serum samples were linked to a basic questionnaire to identify possible risk factors. The majority of the participants (64.8% had extensive exposure to rural areas or farms. Results indicated a C. burnetii prevalence of 26.1% (screening titre 1∶16, and prevalence rates of 11.9% and 14.9% (screening titre 1∶100 for spotted fever group and typhus group rickettsiae, respectively. There was a significant spatial association between C. burnetii exposure and place of residence in southern Namibia (P0.012, especially cattle (P>0.006, were also significantly associated with C. burnetii exposure. Males were significantly more likely than females to have been exposed to spotted fever (P<0.013 and typhus (P<0.011 group rickettsiae. Three (2.9% samples were positive for B. henselae possibly indicating low levels of exposure to a pathogen never reported in Namibia.These results indicate that Namibians are exposed to pathogenic fever-causing bacteria, most of which have flea or tick vectors/reservoirs. The epidemiology of febrile illnesses in Namibia needs further evaluation in order to develop comprehensive local diagnostic and treatment algorithms.

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

Science.gov (United States)

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.

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

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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.

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

International Nuclear Information System (INIS)

Gerarden, Kyle P.; Fuchs, Andrew M.; Koch, Jonathan M.; Mueller, Melissa M.; Graupner, David R.; O’Rorke, Justin T.; Frost, Caleb D.; Heinen, Heather A.; Lackner, Emily R.; Schoeller, Scott J.; House, Paul G.; Peterson, Francis C.; Veldkamp, Christopher T.

2012-01-01

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

Catalase is a determinant of the colonization and transovarial transmission of Rickettsia parkeri in the Gulf Coast tick Amblyomma maculatum.

Science.gov (United States)

Budachetri, K; Kumar, D; Karim, S

2017-08-01

The Gulf Coast tick (Amblyomma maculatum) has evolved as a competent vector of the spotted-fever group rickettsia, Rickettsia parkeri. In this study, the functional role of catalase, an enzyme responsible for the degradation of toxic hydrogen peroxide, in the colonization of the tick vector by R. parkeri and transovarial transmission of this pathogen to the next tick generation, was investigated. Catalase gene (CAT) expression in midgut, salivary glands and ovarian tissues exhibited a 2-11-fold increase in transcription level upon R. parkeri infection. Depletion of CAT transcripts using an RNA-interference approach significantly reduced R. parkeri infection levels in midgut and salivary gland tissues by 53-63%. The role of CAT in transovarial transmission of R. parkeri was confirmed by simultaneously blocking the transcript and the enzyme by injecting double-stranded RNA for CAT and a catalase inhibitor (3-amino-1,2,4-triazole) into gravid females. Simultaneous inhibition of the CAT transcript and the enzyme significantly reduced the egg conversion ratio with a 44% reduction of R. parkeri transovarial transmission. These data suggest that catalase is required for rickettsial colonization of the tick vector and transovarial transmission to the next generation. © 2017 The Royal Entomological Society.

Relative sensitivity of conventional and real-time PCR assays for detection of SFG Rickettsia in blood and tissue samples from laboratory animals.

Science.gov (United States)

Zemtsova, Galina E; Montgomery, Merrill; Levin, Michael L

2015-01-01

Studies on the natural transmission cycles of zoonotic pathogens and the reservoir competence of vertebrate hosts require methods for reliable diagnosis of infection in wild and laboratory animals. Several PCR-based applications have been developed for detection of infections caused by Spotted Fever group Rickettsia spp. in a variety of animal tissues. These assays are being widely used by researchers, but they differ in their sensitivity and reliability. We compared the sensitivity of five previously published conventional PCR assays and one SYBR green-based real-time PCR assay for the detection of rickettsial DNA in blood and tissue samples from Rickettsia- infected laboratory animals (n = 87). The real-time PCR, which detected rickettsial DNA in 37.9% of samples, was the most sensitive. The next best were the semi-nested ompA assay and rpoB conventional PCR, which detected as positive 18.4% and 14.9% samples respectively. Conventional assays targeting ompB, gltA and hrtA genes have been the least sensitive. Therefore, we recommend the SYBR green-based real-time PCR as a tool for the detection of rickettsial DNA in animal samples due to its higher sensitivity when compared to more traditional assays.

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

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Cristina Socolovschi

Full Text Available 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.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.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.

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

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Andrew Woodard

2011-01-01

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.

Tifus Exantemático: enfermedad reemergente en el Perú

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Cecilia Morón C

1999-01-01

Full Text Available El tifus exantemático es producido por la Rickettsia prowazekii y transmitido por el piojo del cuerpo. Ocurre como brotes o epidemias que tienen la potencialidad de afectar a un gran número de personas en semanas a meses. El Perú notifica más del 50% de los casos de tifus exantemático a nivel mundial. El sistema de vigilancia es considerado incompleto debido básicamente a los limitados recursos económicos, la dificultad en las comunicaciones y la existencia de pocos laboratorios con experiencia en el diagnóstico de rickettsias. El diagnóstico laboratorial confirmatorio adecuado, y la búsqueda activa de casos, posiblemente con apoyo de la comunidad, pueden contribuir a fortalecerlo.

Pesquisa de anticorpos anti-Rickettsia rickettsii em eqüinos do Centro de Controle de Zoonoses do município de São Paulo (CCZ/SP

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Jonas Moraes-Filho

2009-04-01

Full Text Available A Febre Maculosa Brasileira (FMB é uma zoonose transmitida por pelo menos duas espécies de carrapatos: Amblyomma cajennense e Amblyomma aureolatum. Os eqüinos assumem um importante papel de sentinela da FMB em áreas onde o carrapato vetor é o A. cajennense, por ser considerado hospedeiro primário dessa espécie de carrapato. O A. aureolatum, cujos hospedeiros primários são aves, alguns roedores silvestres e canídeos, é incriminado como vetor da doença na região da Grande São Paulo. Este trabalho objetivou pesquisar a presença de anticorpos contra Rickettsia rickettsii, agente da FMB, em eqüinos encaminhados ao Centro de Controle de Zoonoses do município de São Paulo (CCZ/SP no período de 2003 a 2005. Após coleta de sangue, o soro obtido pela centrifugação foi submetido à reação de imunofluorescência indireta (RIFI e os animais foram considerados positivos quando as amostras de soro apresentaram títulos >; 64. Durante os três anos, foram testados 363 amostras pela RIFI, sendo que 64 se mostraram reagentes: 6 (2003, 16 (2004 e 42 (2005. Os títulos finais variaram de 64 a 1.024. Os resultados obtidos demonstram uma baixa porcentagem de animais reagentes (17,6% quando comparados com dados de literatura de áreas endêmicas para FMB onde o vetor é o A. cajennense, sugerindo não ser essa espécie responsável pela transmissão da doença na área de estudo

Phylogeography of Rickettsia rickettsii genotypes associated with fatal Rocky Mountain spotted fever.

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

2014-09-01

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

[Severe spotted fever by Rickettsia rickettsii, in tourist in the Argentine Northwest].

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Seijo, Alfredo; Giamperetti, Sergio; Ortiz Mayor, Sonia M; González, María B; Ortega, Eugenia S; González, Rossana C

On the fifth day after leaving the Parque Nacional El Rey, province of Salta, Argentina, where she made rural tourism, a woman of Italian origin, aged 47, developed an acute fever followed by a petechial and purpuric rash that progressed rapidly to multiorgan failure. She died on the sixth day after hospitalization. There were references to tick bites and a skin lesion similar to tache noire was found. The autopsy showed generalized vasculitis, ascites, pulmonary edema, acute tubular necrosis and portal centrilobular necrosis. Spleen and liver tissue were processed for PCR Rickettsia spp, based on the detection of the gltA gene. The result was positive. The amplicons obtained were sequenced and the results were compared with the preset sequences on the BLAST program, 99% coinciding with R. rickettsii. The low sensitivity of the health system to recognize this disease and the insufficient information generated from tourism-related media are factors that affect the delay to implement effective treatment and appropriate prevention standards.

Natural blood feeding and temperature shift modulate the global transcriptional profile of Rickettsia rickettsii infecting its tick vector.

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Maria Fernanda B M Galletti

Full Text Available Rickettsia rickettsii is an obligate intracellular tick-borne bacterium that causes Rocky Mountain Spotted Fever (RMSF, the most lethal spotted fever rickettsiosis. When an infected starving tick begins blood feeding from a vertebrate host, R. rickettsii is exposed to a temperature elevation and to components in the blood meal. These two environmental stimuli have been previously associated with the reactivation of rickettsial virulence in ticks, but the factors responsible for this phenotype conversion have not been completely elucidated. Using customized oligonucleotide microarrays and high-throughput microfluidic qRT-PCR, we analyzed the effects of a 10°C temperature elevation and of a blood meal on the transcriptional profile of R. rickettsii infecting the tick Amblyomma aureolatum. This is the first study of the transcriptome of a bacterium in the genus Rickettsia infecting a natural tick vector. Although both stimuli significantly increased bacterial load, blood feeding had a greater effect, modulating five-fold more genes than the temperature upshift. Certain components of the Type IV Secretion System (T4SS were up-regulated by blood feeding. This suggests that this important bacterial transport system may be utilized to secrete effectors during the tick vector's blood meal. Blood feeding also up-regulated the expression of antioxidant enzymes, which might correspond to an attempt by R. rickettsii to protect itself against the deleterious effects of free radicals produced by fed ticks. The modulated genes identified in this study, including those encoding hypothetical proteins, require further functional analysis and may have potential as future targets for vaccine development.

Molecular Detection of Rickettsia felis in Humans, Cats, and Cat Fleas in Bangladesh, 2013-2014.

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Ahmed, Rajib; Paul, Shyamal Kumar; Hossain, Muhammad Akram; Ahmed, Salma; Mahmud, Muhammad Chand; Nasreen, Syeda Anjuman; Ferdouse, Faria; Sharmi, Rumana Hasan; Ahamed, Farid; Ghosh, Souvik; Urushibara, Noriko; Aung, Meiji Soe; Kobayashi, Nobumichi

2016-05-01

High prevalence of Rickettsia felis in patients with fever of unknown origin was revealed in the north-central Bangladesh from 2012 to 2013. Subsequently, in this study, prevalence of R. felis in cats and cat fleas (Ctenocephalides felis), together with febrile patients, was studied by PCR detection of 17 kDa antigen gene and DNA sequencing. R. felis was detected in 28% (28/100) and 21% (14/68) of cat blood and cat flea samples, respectively, whereas 42% (21/50) of patients were positive for R. felis. R. felis-positive cat fleas were detected at significantly higher rate on R. felis-positive cats. The results suggested a potential role of cats and cat fleas for transmission of R. felis to humans in Bangladesh.

Relative sensitivity of conventional and real-time PCR assays for detection of SFG Rickettsia in blood and tissue samples from laboratory animals.

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Galina E Zemtsova

Full Text Available Studies on the natural transmission cycles of zoonotic pathogens and the reservoir competence of vertebrate hosts require methods for reliable diagnosis of infection in wild and laboratory animals. Several PCR-based applications have been developed for detection of infections caused by Spotted Fever group Rickettsia spp. in a variety of animal tissues. These assays are being widely used by researchers, but they differ in their sensitivity and reliability. We compared the sensitivity of five previously published conventional PCR assays and one SYBR green-based real-time PCR assay for the detection of rickettsial DNA in blood and tissue samples from Rickettsia- infected laboratory animals (n = 87. The real-time PCR, which detected rickettsial DNA in 37.9% of samples, was the most sensitive. The next best were the semi-nested ompA assay and rpoB conventional PCR, which detected as positive 18.4% and 14.9% samples respectively. Conventional assays targeting ompB, gltA and hrtA genes have been the least sensitive. Therefore, we recommend the SYBR green-based real-time PCR as a tool for the detection of rickettsial DNA in animal samples due to its higher sensitivity when compared to more traditional assays.

Optimización de la estadificación clínico-patológica mediante la utilización del aclaramiento anglionar después del estudio de patología convencional en piezas quirúrgicas de pacientes con cáncer de colon y recto

OpenAIRE

Lombana Amaya, Luis Jorge

2010-01-01

Objetivo: Establecer las ventajas de la técnica de aclaramiento ganglionar como método complementario para la detección de ganglios linfáticos en el estudio anatomopatológico de especímenes quirúrgicos de pacientes con cáncer colo-rectal. Diseño: Estudio observacional descriptivo prospectivo. Lugar y población: Pacientes llevados a cirugía por cáncer colo-rectal en el Hospital Universitario San Ignacio y la Clínica Nueva entre Julio de 2009 y Diciembre de 2009. Intervención y medición: despué...

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

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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.

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

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Luciane Daniele Cardoso

2006-03-01

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

Flinders Island spotted fever rickettsioses caused by "marmionii" strain of Rickettsia honei, Eastern Australia.

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Unsworth, Nathan B; Stenos, John; Graves, Stephen R; Faa, Antony G; Cox, G Erika; Dyer, John R; Boutlis, Craig S; Lane, Amanda M; Shaw, Matthew D; Robson, Jennifer; Nissen, Michael D

2007-04-01

Australia has 4 rickettsial diseases: murine typhus, Queensland tick typhus, Flinders Island spotted fever, and scrub typhus. We describe 7 cases of a rickettsiosis with an acute onset and symptoms of fever (100%), headache (71%), arthralgia (43%), myalgia (43%), cough (43%), maculopapular/petechial rash (43%), nausea (29%), pharyngitis (29%), lymphadenopathy (29%), and eschar (29%). Cases were most prevalent in autumn and from eastern Australia, including Queensland, Tasmania, and South Australia. One patient had a history of tick bite (Haemaphysalis novaeguineae). An isolate shared 99.2%, 99.8%, 99.8%, 99.9%, and 100% homology with the 17 kDa, ompA, gltA, 16S rRNA, and Sca4 genes, respectively, of Rickettsia honei. This Australian rickettsiosis has similar symptoms to Flinders Island spotted fever, and the strain is genetically related to R. honei. It has been designated the "marmionii" strain of R. honei, in honor of Australian physician and scientist Barrie Marmion.

Rickettsia felis in cat fleas, Ctenocephalides felis parasitizing opossums, San Bernardino County, California.

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Abramowicz, K F; Wekesa, J W; Nwadike, C N; Zambrano, M L; Karpathy, S E; Cecil, D; Burns, J; Hu, R; Eremeeva, M E

2012-12-01

Los Angeles and Orange Counties are known endemic areas for murine typhus in California; however, no recent reports of flea-borne rickettsioses are known from adjacent San Bernardino County. Sixty-five opossums (Didelphis virginiana) were trapped in the suburban residential and industrial zones of the southwestern part of San Bernardino County in 2007. Sixty out of 65 opossums were infested with fleas, primarily cat fleas, Ctenocephalides felis (Bouché, 1835). The flea minimum infection rate with Rickettsia felis was 13.3% in pooled samples and the prevalence was 23.7% in single fleas, with two gltA genotypes detected. In spite of historic records of murine typhus in this area, no evidence for circulation of R. typhi in fleas was found during the present study. Factors contributing to the absence of R. typhi in these cat fleas in contrast to its presence in cat fleas from Orange and Los Angeles Counties are unknown and need to be investigated further in San Bernardino County. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

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

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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

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

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Schorn, Sabine; Pfister, Kurt; Reulen, Holger; Mahling, Monia; Silaghi, Cornelia

2011-07-15

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. 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. I. ricinus ticks in urban areas of Germany harbor several tick-borne pathogens and coinfections were also observed. Public parks are of particularly great interest regarding the epidemiology of tick-borne pathogens, because of differences in both the prevalence of pathogens in ticks as well as a varying species arrangement when compared to woodland areas. The record of DNA of a Babesia gibsoni-like pathogen detected in I. ricinus suggests that I. ricinus may harbor and transmit more Babesia spp. than previously known. Because of their high recreational value for human beings, urban green areas are likely to remain in the research focus on

Doença da arranhadura do gato por Bartonella quintana em lactente: uma apresentação incomum

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Azevedo Zina Maria Almeida de

2000-01-01

Full Text Available Relato de caso de doença da arranhadura do gato (DAG, em um paciente lactente, com história epidemiológica negativa, descrevendo o rastreamento diagnóstico, a imagem ao ultra-som, a evolução clínica e o prognóstico. B. quintana foi identificada em aspirado de secreção ganglionar pelo método de PCR. B. henselae, embora seja o agente causal habitualmente responsável pela DAG, não foi isolada. Os autores concluem que a pesquisa de B. quintana e B. henselae deve ser incluída na investigação de adenites, principalmente quando a evolução é subaguda, mesmo em lactentes e, ainda que a história epidemiológica seja negativa.

Rickettsia felis in fleas from Catalonia (Northeast Spain).

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Nogueras, María-Mercedes; Pons, Immaculada; Ortuño, Anna; Lario, Sergio; Segura, Ferran

2011-05-01

Rickettsia felis produces a syndrome indistinguishable from murine typhus, which has been described in Spain. R. felis is transmitted to humans by fleas. Although no clinical case has been described so far, serologic evidence of infections in humans, cats, and dogs has been obtained in our area. However, no study has been conducted regarding its presence in vectors. Recognition of routes of transmission is of great importance to prevent infection in humans. Taking into account these results, R. felis seems to be present in animals that are in contact with humans. The aim of this study was to determine the presence of R. felis in the fleas of cats and dogs from Northeast Spain, to show the presence of peridomestic cycle in our area. Between May 2006 and July 2008, 78 fleas were collected. Sixty-three fleas were recovered from kennels. Most of them were collected from cages and a few of them on dogs and cats living in kennels. Fifteen fleas were collected from dogs and cats attended at a veterinary clinic. Fleas were rinsed with ethanol, dried, identified, and stored at 4°C. DNA was extracted from each flea individually. Rickettsial DNA was determined by quantitative real-time polymerase chain reaction. OmpB-specific primers and molecular beacon probes targeting specifically R. felis were used. All 78 fleas were identified as Ctenocephalides felis. R. felis was detected in 34 (43.6%) fleas. No nucleic acids were amplified from negative controls and expected results were obtained from positive controls. Eight positive samples were also confirmed by sequencing. R. felis was found in a high percentage of Ct. felis from cats and dogs. It seems that there is a peridomestic cycle in Northeast Spain, which would allow contact of R. felis with humans.

Flinders Island Spotted Fever Rickettsioses Caused by “marmionii” Strain of Rickettsia honei, Eastern Australia

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Unsworth, Nathan B.; Graves, Stephen R.; Faa, Antony G.; Cox, G. Erika; Dyer, John R.; Boutlis, Craig S.; Lane, Amanda M.; Shaw, Matthew D.; Robson, Jennifer; Nissen, Michael D.

2007-01-01

Australia has 4 rickettsial diseases: murine typhus, Queensland tick typhus, Flinders Island spotted fever, and scrub typhus. We describe 7 cases of a rickettsiosis, with an acute onset and symptoms of fever (100%), headache (71%), arthralgia (43%), myalgia (43%), cough (43%), maculopapular/petechial rash (43%), nausea (29%), pharyngitis (29%), lymphadenopathy (29%), and eschar (29%). Cases were most prevalent in autumn and from eastern Australia, including Queensland, Tasmania, and South Australia. One patient had a history of tick bite (Haemaphysalis novaeguineae). An isolate shared 99.2%, 99.8%, 99.8%, 99.9%, and 100% homology with the 17 kDa, ompA, gltA, 16S rRNA, and Sca4 genes, respectively, of Rickettsia honei. This Australian rickettsiosis has similar symptoms to Flinders Island spotted fever, and the strain is genetically related to R. honei. It has been designated the “marmionii” strain of R. honei, in honor of Australian physician and scientist Barrie Marmion. PMID:17553271

Linfoma óseo primario

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Onilda Labrada Silva

2014-08-01

Full Text Available El linfoma primario de hueso es definido histológicamente como un linfoma extra ganglionar, afecta los huesos y puede ser desarrollado por una enfermedad sistémica. Se presentó un caso de linfoma óseo primario en el Hospital General Docente “Ernesto Guevara de la Serna” de las Tunas en el año 2013, descrito como una forma muy rara de manifestación de los linfomas. Paciente masculino de 72 años de edad, con dolor a nivel del calcáneo derecho, inflamación e impotencia funcional. Se realizaron estudios imaginológicos que revelaron la existencia de osteoporosis y un tumor óseo primario de tipo linfomatoso

Rickettsia amblyommii associado a roedores e marsupiais nativos da Estação Experimental Rafael Fernandes da UFERSA, Rio Grande do Norte

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Kaliane A.R. Paiva

Full Text Available RESUMO: O presente estudo teve como objetivo registrar a ocorrência de Rickettsia sp. em roedores e marsupiais nativos da Estação Experimental Rafael Fernandes da UFERSA, Mossoró/RN. O trabalho consistiu em uma pesquisa de campo, com roedores e marsupiais silvestres, com os dados expressos em frequência simples e porcentagem através do programa estatístico IBM SPSS (Armonk, NY: IBM Corp., versão 22.0. Coletaram-se amostras de plasma sanguíneo de marsupiais (36 e de roedores (5. Destes, 64 continham Amblyomma auricularium, 7 Amblyomma parvum e 12 Amblyomma sp. As amostras de plasma sanguíneo foram analisadas através da técnica de Reação de Imunofluorescência Indireta. Exemplares de A. auricularium e a A. parvum foram macerados e submetidos a Técnica de Reação em Cadeia da Polimerase. Das amostras de plasma testadas, 17,60% apresentaram soropositividade para Rickettsia amblyommii. Oito exemplares de A. auricularium estavam positivos para R. amblyommii na análise de fragmentos dos genes gltA (350 bp e ompA (587 pb, com 100% de similaridade com Candidatus R. amblyommii estirpe Bahia e AaPE, correspondendo a uma baixa circulação do agente dentre os vetores e hospedeiros. Esta pesquisa registra pela primeira vez a ocorrência de R. amblyommii em marsupiais Gracilinanus agilis e Monodelphis domestica pertencentes a Família Didelphidae, e roedores das Famílias Echimyidae e Cricetidae, cujas espécies foram Thrichomys sp. e Wiedomys sp., respectivamente, em Mossoró, estado do Rio Grande do Norte.

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

Institute of Scientific and Technical Information of China (English)

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.

Comparação entre diversos antígenos para o diagnóstico de Anaplasma marginale por ELISA Comparison between several antigens for diagnosis of Anaplasma marginale by ELISA

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Carlos A.N. Ramos

2010-01-01

Full Text Available Anaplasmose bovina é uma doença com grande importância nas regiões tropicais e subtropicais do mundo por determinar perdas econômicas devido à mortalidade e redução da produtividade. É causada por Anaplasma marginale, uma riquétsia intraeritrocítica obrigatória cujo controle requer, além de uma vacina eficiente, uma acurada identificação de bovinos cronicamente infectados. Apesar de existirem atualmente diversos métodos de diagnóstico dessa riquétsia, os métodos sorológicos, em particular o ensaio de imunoadsorção enzimática-ELISAs, são os mais utilizados devido à sua versatilidade e praticidade. No entanto, devido ao grande número de antígenos disponíveis, atualmente torna-se necessária uma avaliação para definir quais antígenos apresentam um melhor desempenho no diagnóstico da anaplasmose. Soros de bovinos positivos e negativos para A. marginale por PCR, e soros de animais provenientes do Brasil e Costa Rica, foram testados em ELISAs baseados em MSP1a, MSP2 e MSP5 recombinantes, um pool das três proteínas recombinantes, e antígeno de lisado de corpúsculos iniciais da riquétsia (CI. Utilizando soro de bovinos positivos para A. marginale por PCR, uma maior sensibilidade foi observada no ELISA CI. No entanto, uma maior especificidade, com soro de bovinos negativos a PCR, foi observada com os ELISAs recombinantes. O porcentual de bovinos positivos do Brasil e Costa Rica foi maior com ELISA CI. Razões para essas diferenças são discutidas.Bovine anaplasmosis is a major disease in tropical and subtropical regions of the world by determine economical loss due mortality and productive reduction. The disease is caused by Anaplasma marginale, an intraerythrocytic rickettsia whose control requires, besides an efficient vaccine, the accurate identification of chronically infected cattle. Although the existence of diverse methods of diagnosis of this rickettsia, the serological methods, in particular the enzyme

Rickettsia parkeri Rickettsiosis in Different Ecological Regions of Argentina and Its Association with Amblyomma tigrinum as a Potential Vector

Science.gov (United States)

Romer, Yamila; Nava, Santiago; Govedic, Francisco; Cicuttin, Gabriel; Denison, Amy M.; Singleton, Joseph; Kelly, Aubree J.; Kato, Cecilia Y.; Paddock, Christopher D.

2014-01-01

Rickettsia parkeri, a newly recognized tick-borne pathogen of humans in the Americas, is a confirmed cause of spotted fever group rickettsiosis in Argentina. Until recently, almost all cases of R. parkeri rickettsiosis in Argentina have originated from the Paraná River Delta, where entomological surveys have identified populations of R. parkeri-infected Amblyomma triste ticks. In this report, we describe confirmed cases of R. parkeri rickettsiosis from Córdoba and La Rioja provinces, which are located several hundred kilometers inland, and in a more arid ecological region, where A. triste ticks do not occur. Additionally, we identified questing A. tigrinum ticks naturally infected with R. parkeri in Córdoba province. These data provide evidence that another human-biting tick species serves as a potential vector of R. parkeri in Argentina and possibly, other countries of South America. PMID:25349376

Descriptions of two new cases of Rocky Mountain spotted fever in Panama, and coincident infection with Rickettsia rickettsii in Rhipicephalus sanguineus s.l. in an urban locality of Panama City, Panama.

Science.gov (United States)

Martínez-Caballero, A; Moreno, B; González, C; Martínez, G; Adames, M; Pachar, J V; Varela-Petrucelli, J B; Martínez-Mandiche, J; Suárez, J A; Domínguez, L; Zaldívar, Y; Bermúdez, S

2018-05-01

The clinical and pathologic characterisation of two fatal cases of tick-borne rickettsiosis in rural (El Valle) and urban (City of Panama) Panama are described. Clinical and autopsy findings were non-specific, but the molecular analysis was used to identify Rickettsia rickettsii in both cases. No ticks were collected in El Valle, while in the urban case, R. rickettsii was detected in Rhipicephalus sanguineus s.l., representing the first molecular finding in this tick in Panama and Central America.

MicroRNA Signature of Human Microvascular Endothelium Infected with Rickettsia rickettsii

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Abha Sahni

2017-07-01

Full Text Available MicroRNAs (miRNAs mediate gene silencing by destabilization and/or translational repression of target mRNA. Infection of human microvascular endothelial cells as primary targets of Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever, triggers host responses appertaining to alterations in cellular gene expression. Microarray-based profiling of endothelial cells infected with R. rickettsii for 3 or 24 h revealed differential expression of 33 miRNAs, of which miRNAs129-5p, 200a-3p, 297, 200b-3p, and 595 were identified as the top five up-regulated miRNAs (5 to 20-fold, p ≤ 0.01 and miRNAs 301b-3p, 548a-3p, and 377-3p were down-regulated (2 to 3-fold, p ≤ 0.01. Changes in the expression of selected miRNAs were confirmed by q-RT-PCR in both in vitro and in vivo models of infection. As potential targets, expression of genes encoding NOTCH1, SMAD2, SMAD3, RIN2, SOD1, and SOD2 was either positively or negatively regulated. Using a miRNA-specific mimic or inhibitor, NOTCH1 was determined to be a target of miRNA 200a-3p in R. rickettsii-infected human dermal microvascular endothelial cells (HMECs. Predictive interactome mapping suggested the potential for miRNA-mediated modulation of regulatory gene networks underlying important host cell signaling pathways. This first demonstration of altered endothelial miRNA expression provides new insights into regulatory elements governing mechanisms of host responses and pathogenesis during human rickettsial infections.

Rickettsia parkeri rickettsiosis and its clinical distinction from Rocky Mountain spotted fever.

Science.gov (United States)

Paddock, Christopher D; Finley, Richard W; Wright, Cynthia S; Robinson, Howard N; Schrodt, Barbara J; Lane, Carole C; Ekenna, Okechukwu; Blass, Mitchell A; Tamminga, Cynthia L; Ohl, Christopher A; McLellan, Susan L F; Goddard, Jerome; Holman, Robert C; Openshaw, John J; Sumner, John W; Zaki, Sherif R; Eremeeva, Marina E

2008-11-01

Rickettsia parkeri rickettsiosis, a recently identified spotted fever transmitted by the Gulf Coast tick (Amblyomma maculatum), was first described in 2004. We summarize the clinical and epidemiological features of 12 patients in the United States with confirmed or probable disease attributable to R. parkeri and comment on distinctions between R. parkeri rickettsiosis and other United States rickettsioses. Clinical specimens from patients in the United States who reside within the range of A. maculatum for whom an eschar or vesicular rash was described were evaluated by > or =1 laboratory assays at the Centers for Disease Control and Prevention (Atlanta, GA) to identify probable or confirmed infection with R. parkeri. During 1998-2007, clinical samples from 12 patients with illnesses epidemiologically and clinically compatible with R. parkeri rickettsiosis were submitted for diagnostic evaluation. Using indirect immunofluorescence antibody assays, immunohistochemistry, polymerase chain reaction assays, and cell culture isolation, we identified 6 confirmed and 6 probable cases of infection with R. parkeri. The aggregate clinical characteristics of these patients revealed a disease similar to but less severe than classically described Rocky Mountain spotted fever. Closer attention to the distinct clinical features of the various spotted fever syndromes that exist in the United States and other countries of the Western hemisphere, coupled with more frequent use of specific confirmatory assays, may unveil several unique diseases that have been identified collectively as Rocky Mountain spotted fever during the past century. Accurate assessments of these distinct infections will ultimately provide a more valid description of the currently recognized distribution, incidence, and case-fatality rate of Rocky Mountain spotted fever.

Surface protein Adr2 of Rickettsia rickettsii induced protective immunity against Rocky Mountain spotted fever in C3H/HeN mice.

Science.gov (United States)

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

2014-04-11

Rickettsia rickettsii is the pathogen of Rocky Mountain spotted fever (RMSF), a life-threatening tick-transmitted infection. Adr2 was a surface-exposed adhesion protein of R. rickettsii and its immunoprotection against RMSF was investigated in mice. Recombinant Adr2 (rAdr2) was used to immunize C3H/HeN mice, and the rickettsial loads in organs of the mice were detected after challenge with R. rickettsii. The levels of specific antibodies of sera from the immunized mice were determined and the sera from immunized mice were applied to neutralize R. rickettsii. Proliferation and cytokine secretion of CD4(+) and CD8(+) T cells isolated from R. rickettsii-infected mice were also assayed after rAdr2 stimulation. After R. rickettsii challenge, the rickettsial loads in spleens, livers, and lungs were significantly lower and the impairment degrees of these organs in rAdr2-immunized mice were markedly slighter, compared with those in negative control mice. The ratio of specific IgG2a/IgG1 of rAdr2-immunized mice kept increasing during the immunization. After treatment with rAdr2-immunized sera, the total number of R. rickettsii organisms adhering and invading host cells was significantly lower than that treated with PBS-immunized sera. Interferon-γ secretion by CD4(+) or CD8(+) T cells and tumor necrosis factor-α secretion by CD4(+) T cells from R. rickettsii-infected mice were respectively significantly greater than those from uninfected mice after rAdr2 stimulation. Adr2 is a protective antigen of R. rickettsii. Protection offered by Adr2 is mainly dependent on antigen-specific cell-mediated immune responses, including efficient activity of CD4(+) and CD8(+) T cells to produce great amount of TNF-α and/or IFN-γ as well as rapid increase of specific IgG2a, which synergistically activate and opsonize host cells to killing intracellular rickettsiae. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

Nelson, O.D.; Keller, G.M.

1997-01-01

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

Rickettsioses in Europe.

Science.gov (United States)

Portillo, Aránzazu; Santibáñez, Sonia; García-Álvarez, Lara; Palomar, Ana M; Oteo, José A

2015-01-01

Bacteria of the genera Rickettsia and Orientia (family rickettsiaceae, order rickettsiales) cause rickettsioses worldwide, and are transmitted by lice, fleas, ticks and mites. In Europe, only Rickettsia spp. cause rickettsioses. With improvement of hygiene, the risk of louse-borne rickettsiosis (epidemic typhus) is low in Europe. Nevertheless, recrudescent form of Rickettsia prowazekii infection persists. There could be an epidemic typhus outbreak if a body lice epidemic occurs under unfavorable sanitary conditions. In Europe, endemic typhus or Rickettsia typhi infection, transmitted by rats and fleas, causes febrile illness. At the beginning of this century, flea-borne spotted fever cases caused by Rickettsia felis were diagnosed. Flea-borne rickettsiosis should be suspected after flea bites if fever, with or without rash, is developed. Tick-borne rickettsioses are the main source of rickettsia infections in Europe. Apart from Rickettsia conorii, the Mediterranean Spotted Fever (MSF) agent, other Rickettsia spp. cause MSF-like: Rickettsia helvetica, Rickettsia monacensis, Rickettsia massiliae or Rickettsia aeschlimannii. In the 1990s, two 'new' rickettsioses were diagnosed: Lymphangitis Associated Rickettsiosis (LAR) caused by Rickettsia sibirica mongolitimonae, and Tick-Borne Lymphadenopathy/Dermacentor-Borne-Necrosis-Erythema-Lymphadenopathy/Scalp Eschar Neck Lymphadenopathy (TIBOLA/DEBONEL/SENLAT), caused by Rickettsia slovaca, Candidatus Rickettsia rioja and Rickettsia raoultii. Lastly, European reports about mite-borne rickettsiosis are scarce. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Evaluation of a Spotted Fever Group Rickettsia Public Health Surveillance System in Tennessee.

Science.gov (United States)

Fill, Mary-Margaret A; Moncayo, Abelardo C; Bloch, Karen C; Dunn, John R; Schaffner, William; Jones, Timothy F

2017-09-01

Spotted fever group (SFG) rickettsioses are endemic in Tennessee, with ∼2,500 cases reported during 2000-2012. Because of this substantial burden of disease, we performed a three-part evaluation of Tennessee's routine surveillance for SFG rickettsioses cases and deaths to assess the system's effectiveness. Tennessee Department of Health (TDH) SFG rickettsioses surveillance records were matched to three patient series: 1) patients with positive serologic specimens from a commercial reference laboratory during 2010-2011, 2) tertiary medical center patients with positive serologic tests during 2007-2013, and 3) patients identified from death certificates issued during 1995-2014 with SFG rickettsiosis-related causes of death. Chart reviews were performed and patients were classified according to the Council of State and Territorial Epidemiologists' case definition. Of 254 SFG Rickettsia -positive serologic specimens from the reference laboratory, 129 (51%) met the case definition for confirmed or probable cases of rickettsial disease after chart review. The sensitivity of the TDH surveillance system to detect cases was 45%. Of the 98 confirmed or probable cases identified from the medical center, the sensitivity of the TDH surveillance system to detect cases was 34%. Of 27 patients identified by death certificates, 12 (44%) were classified as confirmed or probable cases; four (33%) were reported to TDH, but none were correctly identified as deceased. Cases of SFG rickettsioses were underreported and fatalities not correctly identified. Efforts are needed to improve SFG rickettsiosis surveillance in Tennessee.

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

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F.H. Otomura

2010-06-01

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

Clinical Manifestations and Outcomes of Rickettsia australis Infection: A 15-Year Retrospective Study of Hospitalized Patients

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Adam Stewart

2017-06-01

Full Text Available Queensland tick typhus (QTT; Rickettsia australis is an important cause of community-acquired acute febrile illness in eastern Australia. Cases of QTT were identified retrospectively from 2000 to 2015 at five sites in Northern Brisbane through a pathology database. Those included had a fourfold rise in spotted fever group (SFG-specific serology, a single SFG-specific serology ≥ 256 or SFG-specific serology ≥ 128 with a clinically consistent illness. Cases were excluded on the basis of clinical unlikelihood of QTT infection. Thirty-six cases were included. Fever was found in 34/36 (94% patients. Rash occurred in 83% of patients with maculopapular being the dominant morphology (70%. Thrombocytopenia, lymphopenia, and raised transaminases were common and occurred in 58%, 69%, and 89% of patients, respectively. Thirty-one of 36 (86% patients received antibiotic therapy (usually doxycycline and the time to correct antibiotic (from admission ranged from 3 to 120 h (mean 45.5 h. Four of 36 (11% required intensive care unit (ICU admission for severe sepsis and end-organ support. There were no deaths. QTT has a wide range of clinical and laboratory features. Early and appropriate antimicrobial therapy is important and may prevent severe disease. Further prospective studies are required to identify factors associated with severe infection and sepsis.

Celulitis por citomegalovirus

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A. Ruiz Lascano

2002-12-01

Full Text Available Las lesiones cutáneas por citomegalovirus (CMV son infrecuentes y a menudo una manifestación tardía de una enfermedad sistémica, que generalmente anuncia un curso fatal. Comunicamos un caso de celulitis por CMV: una mujer de 70 años con trasplante renal efectuado 1 mes antes de la consulta, terapia inmunosupresora con ciclosporina A y metilprednisona. La paciente ingresó por fiebre, dolor e impotencia funcional en pierna derecha. Comprobamos la existencia de una placa de 8 por 4 cm eritematoedematosa. La tratamos con antibióticos sin mejoría, por lo que realizamos un estudio histopatológico de piel que mostró cambios citopáticos compatibles con infección por CMV. Los cultivos bacteriológicos y micológicos fueron negativos. La inmunohistoquímica específica para CMV y el estudio de reacción en cadena de la polimerasa (PCR de la biopsia de piel fueron positivas, al igual que la antigenemia. El tratamiento con ganciclovir produjo la mejoría del cuadro clínico. En la literatura revisada no hemos encontrado la celulitis como manifestación de enfermedad cutánea por CMV.

Constrição campimétrica causada por vigabatrin Visual field constriction caused by vigabatrin

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Mário Luiz Ribeiro Monteiro

2000-10-01

Full Text Available Objetivo: Descrever dois pacientes que apresentaram constrição campimétrica importante e determinar a origem desta alteração visual causada pelo uso de vigabatrin, um anticonvulsivante que atua aumentando a concentração do ácido gama-aminobutírico no sistema nervoso central. Métodos: Os pacientes foram submetidos a exame e neuroftalmológico completo, avaliação cuidadosa da retina, campo visual com perímetro de Goldmann, tomografia computadorizada de crânio e órbitas, eletrorretinograma (ERG, imagem por ressonância magnética (1 paciente e potencial visual evocado (1 paciente. Resultados: A acuidade visual se mostrou preservada; o primeiro paciente apresentava campo visual restrito à área central de 20 a 30 graus centrais e o segundo uma constrição leve a moderada. Os exames de neuroimagem foram normais assim como o potencial visual evocado. Observou-se palidez discreta de papila em 3 olhos estudados e estreitamento arteriolar muito discreto dos vasos retinianos. O ERG revelou alterações importantes caracterizada por redução da onda b (caso 1 e dos potenciais oscilatórios (caso 2. Conclusões: As alterações visuais causadas pelo vigabatrin são devidas a uma alteração retiniana, envolvendo provavelmente as células amácrimas, bipolares e ganglionares mas não se acompanham de uma alteração significativa à fundoscopia. Pacientes recebendo esta medicação devem ser seguidos de perto especialmente através da avaliação do campo visual central e periférico.Purpose: To describe two patients who presented with severe campimetric constriction and to determine the source of visual symptoms caused by vigabatrin, an anticonvulsant medication that increases brain gamma-aminobutyric acid. Methods: Patients were submitted to a complete neuroophthalmologic evaluation as well as a careful retina examination, Goldmann perimetry, computerized tomography of the brain and orbits, electroretinograms (ERG, magnetic ressonance

Presentación clínica de tuberculosis en pacientes VIH+ atendidos en el Hospital Santo Tomás, Panamá. Enero a julio del 2009

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Bernardino Denis

2010-01-01

Full Text Available Objetivo: describir las presentaciones clínicas de la tuberculosis en los pacientes VIH+ atendidos en el Hospital Santo Tomás de enero a julio de 2009. Metodología: se trata de un estudio descriptivo retrospectivo que consistió en la revisión de expedientes clínicos de los pacientes que presentaron coinfección de tuberculosis y VIH en el Hospital Santo Tomás durante el primer semestre del año 2009. Se analizó el universo de pacientes. Se utilizó un formulario para la recolección de los datos y para el análisis de los datos se calcularon frecuencias, modas, medianas y promedios. Se utilizo el programa EpiInfo 3.5.1 y se realizaron los gráficos con Microsoft Office Excel. Resultados: La relación hombres : mujeres fue de 3 : 1. Se observó una mayor frecuencia de pacientes procedentes del corregimiento de Juan Díaz (13,5% Calidonia (10,4% Santa Ana (10,4%. La presentación clínica predominante fue la pulmonar (64,4% seguida por la mixta (20% y la extrapulmonar (15,6%; entre las formas extrapulmonares la más frecuente fue la ganglionar (37,5%. Conclusiones: La presentación clínica pulmonar reporta es de 64,4%; extrapulmonar, 15,6%; y mixta, 20,0%. Entre las presentaciones extrapulmonares, la presentación ganglionar se reporta en 37,5%. El método clínico radiológico es el medio diagnóstico más usado (76% a diferencia de otros estudios.

Serologic evidence for exposure to Rickettsia rickettsii in eastern Arizona and recent emergence of Rocky Mountain spotted fever in this region.

Science.gov (United States)

Demma, Linda J; Traeger, Marc; Blau, Dianna; Gordon, Rondeen; Johnson, Brian; Dickson, Jeff; Ethelbah, Rudy; Piontkowski, Stephen; Levy, Craig; Nicholson, William L; Duncan, Christopher; Heath, Karen; Cheek, James; Swerdlow, David L; McQuiston, Jennifer H

2006-01-01

During 2002 through 2004, 15 patients with Rocky Mountain spotted fever (RMSF) were identified in a rural community in Arizona where the disease had not been previously reported. The outbreak was associated with Rickettsia rickettsii in an unexpected tick vector, the brown dog tick (Rhipicephalus sanguineus), which had not been previously associated with RMSF transmission in the United States. We investigated the extent of exposure to R. rickettsii in the local area through serologic evaluations of children and dogs in 2003-2004, and in canine sera from 1996. Antibodies to R. rickettsii at titers > or = 32 were detected in 10% of children and 70% of dogs in the outbreak community and 16% of children and 57% of dogs in a neighboring community. In comparison, only 5% of canine samples from 1996 had anti-R. rickettsii antibodies at titers > or = 32. These results suggest that exposures to RMSF have increased over the past 9 years, and that RMSF may now be endemic in this region.

As formações em bolas argênticas do sistema nervoso simpático

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José Fernandez

1957-09-01

Full Text Available Foram estudados, histològicamente, gânglios simpáticos provenientes de 40 pacientes portadores de enfermidades variadas e 40 gânglios tidos como normais, para pesquisar as formações cm bolas argênticas. As impregnações foram feitas pelos métodos de Cajal, Arteta, Castro, Gros, Bielschowsky e Agduhr. Foi verificado que a presença de bolas argênticas é mais constante nas doenças circulatórias periféricas; nestas afecções, foi verificada, também, a presença de um pigmento corável pelos tricrômios de Gomori e de Goldner e que, possìvelmente, tem o mesmo significado que os descritos por Fedorow 12 corados pelo vermelho neutro; tais pigmentos foram relacionados com as formações em bolas argênticas, levando em consideração os trabalhos experimentais dos autores da escola russa. A presença das formações em bolas argênticas, tanto nos casos normais como nos patológicos, é atribuída a uma hiperfunção, por excitação, do simpático, por serem mais numerosas nos casos de transtornos periféricos. Foi observado que os neurônios em íntimo contacto com as formações em bolas argênticas, apresentam sempre alterações que vão desde o grau mais leve (tumefação do soma celular, retificação dos prolongamentos, neurofibrilas mais fortemente impregnadas, até o mais grave (hiperplasia e hipertrofia dos dendritos, degeneração retrátil, degeneração pigmentar. Foi notado que as terminações das fibras pré-ganglionares e as próprias fibras apresentam, muitas vêzes, alterações (hipertrofia, sinuosidade e grande poder de impregnação; as bolas argênticas foram observadas tanto no final dos dendritos como no das fibras pré-ganglionares. Foram encontradas formações de bolas argênticas em rosário, concluindo-se que elas têm a mesma significação que as alterações claviformes. Conclui-se, finalmente, que as bolas argênticas são produtos patológicos.

Manifestaciones clínicas y hallazgos de laboratorio de una serie de casos febriles agudos con diagnóstico presuntivo de infección por el virus dengue. Quindío (Colombia

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Carlos Andrés Rodríguez-Salazar

Full Text Available Objetivo: Describir las manifestaciones clínicas y hallazgos de laboratorio de una serie de casos febriles agudos con diagnóstico presuntivo de infección por el virus dengue. en Quindío (Colombia. Materiales y métodos: Se realizó un estudio de corte transversal, en pacientes con sospecha clínica de dengue en el periodo comprendido entre enero y agosto de 2013, en algunos centros hospitalarios del departamento del Quindío. Se tomaron muestras de sangre para diagnóstico de dengue, leptospira, malaria, hepatitis B, y rickettsiosis. Como pruebas confirmatorias para dengue se realizó aislamiento viral en células C6/36HT y serotipificación para dengue por RTPCR; pruebas de función hepática, cuadro hemático y niveles de citocinas. Resultados: Se caracterizaron 149 casos, de los cuales el 43% presentaron infección por dengue, 4% leptospira, 6,8% rickettsias, un caso de malaria y uno de hepatitis B. En 5 casos se logró el aislamiento del DENV2 y DENV3. Mediante la RT-PCR, se evidenció cocirculación de serotipos 2, 3, 4. Se encontró que las enzimas AST/ALT, el conteo de plaquetas, la erupción y el dolor abdominal fueron marcadores característicos de la infección por dengue, mientras la ictericia y el dolor lumbar se correlacionaron con la leptospirosis. Los valores de citocinas mostraron que la IL-10, TNF α variaron significativamente en casos con dengue frente a otros diagnósticos, y la IL-17 a presentó diferencias significativas en individuos con dengue grave. Conclusiones: El dengue se confirmó como causa etiológica importante de síndrome febril icterohemorrágico en el departamento del Quindío, pero la leptospirosis y la rickettsiosis tienen también una participación importante. Sin embargo, en el 44% de los casos fueron catalogados como síndrome febril indeterminado.

Portable exhauster POR-007/Skid E and POR-008/Skid F storage plan

International Nuclear Information System (INIS)

Nelson, O.D.

1998-01-01

This document provides storage requirements for 1,000 CFM portable exhausters POR-O07/Skid E and POR-008/Skid F. These requirements are presented in three parts: preparation for storage, storage maintenance and testing, and retrieval from storage. The exhauster component identification numbers listed in this document contain the prefix POR-007 or POR-008 depending on which exhauster is being used

Gamma-irradiated scrub typhus immunogens: development of cell-mediated immunity after vaccination of inbred mice

International Nuclear Information System (INIS)

Jerrells, T.R.; Palmer, B.A.; Osterman, J.V.

1983-01-01

Mice immunized with three injections of gamma-irradiated Karp strain of Rickettsia tsutsugamushi were evaluated for the presence of cell-mediated immunity by using delayed-type hypersensitivity, antigen-induced lymphocyte proliferation, and antigen-induced lymphokine production. These animals also were evaluated for levels of circulating antibody after immunization as well as for the presence of rickettsemia after intraperitoneal challenge with viable Karp rickettsiae. After immunization with irradiated Karp rickettsiae, a demonstrable cell-mediated immunity was present as evidenced by delayed-type hypersensitivity responsiveness, lymphocyte proliferation, and production of migration inhibition factor and interferon by immune spleen lymphocytes. Also, a reduction in circulating rickettsiae was seen in mice immunized with irradiated rickettsiae after challenge with 1,000 50% mouse lethal doses of viable, homologous rickettsiae. All responses except antibody titer and reduction of rickettsemia were similar to the responses noted in mice immunized with viable organisms. Antibody levels were lower in mice immunized with irradiated rickettsiae than in mice immunized with viable rickettsiae. Furthermore, mice that were immunized with viable rickettsiae demonstrated markedly lower levels of rickettsemia after intraperitoneal challenge compared with either mice immunized with irradiated rickettsiae or nonimmunized mice

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

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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.

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

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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.

Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System.

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Dhana G Gorasia

2016-08-01

Full Text Available The type IX secretion system (T9SS has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32-36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component.

Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System.

Science.gov (United States)

Gorasia, Dhana G; Veith, Paul D; Hanssen, Eric G; Glew, Michelle D; Sato, Keiko; Yukitake, Hideharu; Nakayama, Koji; Reynolds, Eric C

2016-08-01

The type IX secretion system (T9SS) has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32-36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component.

Encefalitis aguda: Manifestaciones neuropsiquiátricas como expresión de infección por virus de influenza Acute encephalitis: Neuropsychiatric manifestations as expression of influenza virus infection

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Noris Moreno-Flagge

2009-01-01

Full Text Available El objetivo fue revisar la encefalitis en niños y adolescentes, su etiología, manifestaciones clínicas, fisiopatología, métodos diagnósticos y tratamiento, enfatizando las manifestaciones neuropsiquiátricas de la encefalitis durante una epidemia de influenza. La encefalitis se considera una inflamación del sistema nervioso central (SNC que compromete el cerebro. Se manifiesta usualmente por cefaleas, fiebre y trastorno del estado de conciencia. Puede además manifestarse por convulsiones, cambios en la personalidad y manifestaciones obsesivas (síntomas neuropsiquiátricos. Las manifestaciones dependerán del tipo de virus y las células afectadas. La encefalitis puede ser causada por una gran variedad de agentes infecciosos incluyendo virus, bacterias, hongos y parásitos. Causas virales de encefalitis incluyen herpesvirus, arbovirus, rabia y enterovirus. Casos establecidos de bacterias incluyen Borrelia burgdorferi y rickettsia y el Mycoplasma neumoniae, al cual se atribuyen varios casos de encefalitis. Otros agentes como el hongo Coccidioides immitis e Histoplasma capsulatum pueden también generarla. Más de 100 agentes se han asociado a encefalitis. El diagnóstico de encefalitis constituye un reto para el clínico, y su etiología infecciosa usualmente se identifica entre el 40% al 70% de casos. El diagnóstico se hace con absoluta certeza sólo con una biopsia cerebral. La epidemiología depende de ciertos factores como la edad, la localización geográfica, la época del año, las condiciones climáticas y la inmunocompetencia del huésped. El tratamiento temprano puede disminuir el riesgo de muerte y las secuelas. Describimos cuatro pacientes con encefalitis y manifestaciones neuropsiquiátricas durante una epidemia de influenza, con el fin de alertar sobre esta asociación.The aim is to review the encephalitis in infants and adolescents as well as its etiology, clinical manifestation, epidemiology, physiopathology, diagnostic

The PorX response regulator of the Porphyromonas gingivalis PorXY two-component system does not directly regulate the Type IX secretion genes but binds the PorL subunit.

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Maxence S Vincent

2016-08-01

Full Text Available The Type IX secretion system (T9SS is a versatile multi-protein complex restricted to bacteria of the Bacteriodetes phylum and responsible for the secretion of surface attachment of diverse proteins that participate to S-layer formation, gliding motility or pathogenesis. The T9SS is poorly characterized but a number of proteins involved in the assembly of the secretion apparatus in the oral pathogen Porphyromonas gingivalis have been identified based on genome substractive analyses. Among these proteins, PorY and PorX encode typical two-component system (TCS sensor and CheY-like response regulator respectively. Although the porX and porY genes do not localize at the same genetic locus, it has been proposed that PorXY form a bona fide TCS. Deletion of the porX in P. gingivalis causes a slight decrease of the expression of a number of other T9SS genes, including sov, porT, porP, porK, porL, porM, porN and porY. Here, we show that PorX and the soluble cytoplasmic domain of PorY interact. Using electrophoretic mobility shift, DNA-protein co-purification and heterologous host expression assays, we showed that PorX does not bind and does not directly regulate expression of the T9SS genes. Finally, we show that PorX interacts with the cytoplasmic domain of PorL, a component of the T9SS membrane core complex and propose that the CheY-like PorX protein might be involved in the dynamics of the T9SS.

Transmission dynamics and control of Rickettsia rickettsii in populations of Hydrochoerus hydrochaeris and Amblyomma sculptum.

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Gina Polo

2017-06-01

Full Text Available Brazilian Spotted Fever (BSF, caused by the bacterium Rickettsia rickettsii, is the tick-borne disease that generates the largest number of human deaths in the world. In Brazil, the current increase of BSF human cases has been associated with the presence and expansion of capybaras Hydrochoerus hydrochaeris, which act as primary hosts for the tick Amblyomma sculptum, vector of the R. rickettsii in this area.We proposed a semi-discrete-time stochastic model to evaluate the role of capybaras in the transmission dynamics of R. rickettsii. Through a sensitivity analysis, we identified the parameters with significant influence on the R. rickettsii establishment. Afterward, we implemented the Gillespie's algorithm to simulate the impact of potential public health interventions to prevent BSF human cases.The introduction of a single infected capybara with at least one infected attached tick is enough to trigger the disease in a non-endemic area. We found that to avoid the formation of new BSF-endemic areas, it is crucial to impede the emigration of capybaras from endemic areas by reducing their birth rate by more than 58%. Model results were corroborated by ex-situ data generated from field studies, and this supports our proposal to prevent BSF human cases by implementing control strategies focused on capybaras.The proposed stochastic model illustrates how strategies for the control and prevention of vector-borne infectious diseases can be focused on amplifier hosts management practices. This work provides a basis for future prevention strategies for other neglected vector-borne diseases.

The PorX Response Regulator of the Porphyromonas gingivalis PorXY Two-Component System Does Not Directly Regulate the Type IX Secretion Genes but Binds the PorL Subunit

Science.gov (United States)

Vincent, Maxence S.; Durand, Eric; Cascales, Eric

2016-01-01

The Type IX secretion system (T9SS) is a versatile multi-protein complex restricted to bacteria of the Bacteriodetes phylum and responsible for the secretion or cell surface exposition of diverse proteins that participate to S-layer formation, gliding motility or pathogenesis. The T9SS is poorly characterized but a number of proteins involved in the assembly of the secretion apparatus in the oral pathogen Porphyromonas gingivalis have been identified based on genome substractive analyses. Among these proteins, PorY, and PorX encode typical two-component system (TCS) sensor and CheY-like response regulator respectively. Although the porX and porY genes do not localize at the same genetic locus, it has been proposed that PorXY form a bona fide TCS. Deletion of porX in P. gingivalis causes a slight decrease of the expression of a number of other T9SS genes, including sov, porT, porP, porK, porL, porM, porN, and porY. Here, we show that PorX and the soluble cytoplasmic domain of PorY interact. Using electrophoretic mobility shift, DNA-protein co-purification and heterologous host expression assays, we demonstrate that PorX does not bind T9SS gene promoters and does not directly regulate expression of the T9SS genes. Finally, we show that PorX interacts with the cytoplasmic domain of PorL, a component of the T9SS membrane core complex and propose that the CheY-like PorX protein might be involved in the dynamics of the T9SS. PMID:27630829

OCORRÊNCIA DE Rhipicephalus sanguineus EM TRABALHADORES DE CLÍNICAS VETERINÁRIAS E CANIS, NO MUNICÍPIO DE GOIÂNIA, GO

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Lígia Miranda Ferreira Borges

2006-10-01

Full Text Available Rhipicephalus sanguineus é um parasito natural de cães que eventualmente pode parasitar outros hospedeiros, entre eles o homem. Para humanos, este carrapato é vetor do agente da febre botonosa (Rickettsia conori na Europa e vetor potencial no Brasil dos agentes da febre maculosa (Rickettsia rickettsii e da borreliose Lyme símile (Borrelia sp.. Considerando a importância deste carrapato, desenvolveu-se este trabalho com o objetivo de avaliar a sua ocorrência em humanos no Brasil, uma vez que não se conhecem outros relatos. A presença de carrapatos foi avaliada em 46 trabalhadores de ambos os sexos (25 mulheres e21 homens, de oito clínicas e três canis, por meio de questionário e da identificação dos carrapatos encontrados. Do total de pessoas avaliadas, 68% das mulheres e 71% dos homens relataram já ter encontrado carrapatos andando ou fixados, após contato com cães. Foram colhidos três larvas, uma ninfa e quatro adultos (três machos e uma fêmea sendo todos identificados como da espécie R. sanguineus. Desta forma este é o primeiro relato do parasitismo de humanos por este carrapato no Brasil. PALAVRAS-CHAVE: Carrapatos de cão, humanos, Brasil.

Encefalopatía por priones

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Carlos Colegial

1999-01-01

Full Text Available Las encefalopatías espongiformes por priones son enfermedades neurodegenerativas que pueden ser esporádicas o transmisibles, ya sea por mecanismos infecciosos o hereditarios. Su investigación ha planteado enormes retos y en el recorrido histórico en busca de su causa dos médicos han recibido el premio Nobel de Medicina: Carleton Gajdusek, por sus trabajos en Nueva Guinea donde describió la transmisión infecciosa por ritos canibalísticos, que llevó a estudios de transmisión experimental en chimpancés y a su teoría de los "virus lentos" (por el largo período de incubación de la enfermedad.

Casipoemas por Navidad : (1969-2010)

OpenAIRE

Sena Medina, Guillermo

2011-01-01

PRESENTACIÓN AL AIRE DE LA POESÍA RELIGIOSA Y NAVIDEÑA DE GUILLERMO SENA MEDINA Constituye un gran honor hacer la presentación de Guillermo Sena Medina por un doble motivo; por la larga y sincera amistad que nos une desde hace muchos años al socaire de nuestra común afición por la Historia, como cronistas oficiales de nuestros municipios; y, sobre todo y particularmente, por su rica y profunda personalidad como hombre de letras, nacida de su aún más rica y profunda personalidad humana. A...

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

DEFF Research Database (Denmark)

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 ...... (available from the SRA at NCBI). All three genes were shown to be functional upon reconstitution into nanodiscs, confirming that none of the isoforms are pseudogenes....

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

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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

Retinal properties of the mesopelagic fish Diaphus sp.: vision under dim light conditions

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José Rui Lima Paitio

2014-06-01

In this study, retinal wholemounting technique was applied to study characteristics and sensitivity of the myctophid Diaphus sp. retinae. This technique produces topographic maps of photoreceptor and retinal ganglionar cells, showing how these fishes are adapted to the specific light regime of mesopelagic zone.

Osteomalacia inducida por tumor: hemangiopericitoma rinosinusal

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Enriqueta M. Serafini

2013-02-01

Full Text Available La osteomalacia inducida por tumor es una rara enfermedad del metabolismo óseo caracterizada por el aumento en la excreción de fosfato a nivel renal seguido de hipofosfatemia. Es causada por agentes fosfatúricos producidos por determinados tumores. La resección total del tumor resulta en la completa reversión de las anormalidades bioquímicas, la desaparición de las manifestaciones clínicas y los hallazgos en los estudios por imágenes. Presentamos el caso de un varón de 61 años con cuadro clínico y laboratorio compatibles con osteomalacia oncogénica inducida por tumor mesenquimático de localización rinosinusal. En nuestro caso el diagnóstico histológico correspondió a una neoplasia de tipo vascular: hemangiopericitoma.

Tuberculosis. Lung and extrapulmonary compromise (cutaneous and ganglionar)

International Nuclear Information System (INIS)

Paez Mildred; Neira, Myriam Consuelo; Latorre Pablo; Faisal, Michel

2000-01-01

We present the case or a male, 28 year old that consulted for fever, weight loss and axillary ulcer. Clinically had two skin lesions where cutaneous tuberculosis was proven (lupus vulgaris-scrofuloderma). The skin lesions led to the diagnosis of lung tuberculosis and tuberculous adenitis. In this case all the diagnostic criteria for cutaneous tuberculosis were completed: active presence of tuberculosis in another place, positive reaction to tuberculin test, physical signs and appropriate answer to the treatment

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

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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.

A molecular survey of Rickettsia felis in fleas from cats and dogs in Sicily (Southern Italy.

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Elisabetta Giudice

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

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

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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

Porøse materialer

DEFF Research Database (Denmark)

Hansen, Ernst Jan de Place

2000-01-01

Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM).......Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM)....

Is sarcoidosis a rickettsiosis? An archival study

DEFF Research Database (Denmark)

Svendsen, Claus Bo; Milman, Nils; Andersen, Claus B

2011-01-01

Based on earlier research, Rickettsia helvetica could possibly be involved in the pathogenesis of sarcoidosis. Rickettsiae are transmitted to humans by a tick vector, Ixodes ricinus; this tick is highly prevalent in Northern Europe. We aimed to investigate the association between evidence...... of rickettsiae and sarcoidosis in histological samples....

Verdad por definición

OpenAIRE

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 ...

Electrocardiografo por computadora

OpenAIRE

Tinoco Hernandez, Rosanna; Paredes Bejarano, Margarita; Romero Chaglia, Norman; Yapur Auad, Miguel Eduardo

2009-01-01

El presente trabajo trata sobrees el diseño y la implementación de un graficador de señales cardiacas por computadora, para lo cual diseñamos un circuito electrónico capaz de recibir la senal analógica proveniente de la actividad electrica del corazón , amplificarla, y luego convertirla en una señal digital para ser procesada por software y finalmente ser graficada, siendo posible así observar la señal cardiaca en el monitor de un computador como un tren de pulsos. Cabe destacar que par...

Zoonotic and infectious disease surveillance in Central America: Honduran feral cats positive for toxoplasma, trypanosoma, leishmania, rickettsia, and Lyme disease.

Science.gov (United States)

McCown, Michael; Grzeszak, Benjamin

2010-01-01

A recent zoonotic and infectious disease field surveillance study in Honduras resulted in the discovery of Toxoplasma, Trypanosoma, Leishmania, Rickettsia, and Lyme disease with statistically high prevalence rates in a group of feral cats. All five diseases--Toxoplasmosis, Trypanosomiasis, Leishmaniasis, Rickettsiosis, and Lyme disease--were confirmed in this group of cats having close contact to local civilians and U.S. personnel. These diseases are infectious to other animals and are known to infect humans as well. In the austere Central and South American sites that Special Operations Forces (SOF) medics are deployed, the living conditions and close quarters are prime environments for the potential spread of infectious and zoonotic disease. This study?s findings, as with previous veterinary disease surveillance studies, emphasize the critical need for continual and aggressive surveillance for zoonotic and infectious disease present within animals in specific areas of operation (AO). The importance to SOF is that a variety of animals may be sentinels, hosts, or direct transmitters of disease to civilians and service members. These studies are value-added tools to the U.S. military, specifically to a deploying or already deployed unit. The SOF medic must ensure that this value-added asset is utilized and that the findings are applied to assure Operational Detachment-Alpha (SFOD-A) health and, on a bigger scale, U.S. military force health protection and local civilian health. © 2010.

Mammary neoplasm inflammatory: clinic presentation: combined treatment value; Cancer inflamatorio de mama: presentacion clinica: valor de los tratamientos combinados

Energy Technology Data Exchange (ETDEWEB)

Viola Alles, A; Sabini Gaye, G; Barrios Herrera, E; Muse Sevrini, I

1995-06-01

On a total of 1152 patients bearing of cancer of she suckles tried in the period 1978-1988, 41 of she(3.5% )corresponding to the variety inflamatory. Her ages was understood between 26 and 73 years , was been 15(63,5% )postmenopause. Clinically they presented commitment mammary exclusive 34,1%, invasion ganglionar lorregional 48,7% and 17% was disseminated remaining. The initial treatment bases on 3-4 cycles of chemotherapy type FCA, safe in patient with more years that they received the association CMF. All then were irradiated with dose of 5000-6000 cGy on she suckles and territories ganglionares. Finish the treatment with 6 to 8 additional cycles of the patients' chemotherapy. Nobody it was subjected to surgical. The middle survive of the population's total it was of 22 meses, has been of 26 for the premenopause and 15 for the posmenopause. The percentage of relapses arrive to 30% and 45% in the located ways they were disseminated during its evolution. It highlights that the therapeutic strategy you bases on the association open chemotherapy, radiotherapy remaining the possibility of the handling of high citostatics dose with or without transplants of osseous medulla osea (Author) [Spanish] Sobre un total de 1152 pacientes portadoras de cancer de mama tratadas en el periodo 1978-1988, 41 de ellas(3.5%)correspondieron a la variedad inflamatoria. Sus edades estaban comprendidas entre 26 y 73 an os,siendo 15(63,5%) posmenopausicas. Clinicamente presentaron compromiso mamario exclusivo 34,1%, invasion ganglionar lorregional 48,7% y estaban diseminadas 17% resptantes. El tratamiento inicial se baso en 3-4 ciclos de quimioterapia tipo FCA, salvo en pacientes anosas que recibieron la asociacion CMF. Todas ellas luego se irradiaron con dosis de 5000-6000 cGy sobre mama y territorios ganglionares. Se culmino el tratamiento con 6 a 8 ciclos adicionales de quimioterapia. Ninguna de las pacientes fue sometida a cirugia. La sobrevida media del total de la poblacion fue de 22

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

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Martina Schrallhammer

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

Effect of Rickettsia felis Strain Variation on Infection, Transmission, and Fitness in the Cat Flea (Siphonaptera: Pulicidae).

Science.gov (United States)

Healy, Sean P; Brown, Lisa D; Hagstrom, Melena R; Foil, Lane D; Macaluso, Kevin R

2017-07-01

Rickettsia felis is a human pathogen transmitted by the cat flea, Ctenocephalides felis (Bouché) (str. LSU), as well as an obligate symbiont of the parthenogenic booklouse Liposcelis bostrychophila (Badonnel) (str. LSU-Lb). The influence of genetic variability in these two strains of R. felis on host specialization and fitness and possible resulting differences on infection and transmission kinetics in C. felis is unknown. Utilizing an artificial host system, cat fleas were exposed to a R. felis str. LSU-Lb-infected bloodmeal and monitored for infection at 7-d intervals for 28 d. Quantitative real-time PCR was used to determine rickettsial load and infection density in newly exposed cat fleas, and transmission frequency between cat fleas. The effect of persistent R. felis infection on cat flea F1 progeny was also assessed. At 7 d postexposure 76.7% of the cat fleas successfully acquired R. felis str. LSU-Lb. In R. felis str. LSU-Lb-exposed cat fleas, the mean infection load (6.15 × 106), infection density (0.76), and infection prevalence (91/114) were significantly greater than R. felis str. LSU infection load (3.09 × 106), infection density (0.68), and infection prevalence (76/113). A persistent R. felis str. LSU-Lb infection was detected for 28 d in adult cat fleas but neither female:male ratio distortion nor vertical transmission was observed in F1 progeny. While infection kinetics differed, with higher intensity associated with R. felis str. LSU-Lb, no distinct phenotype was observed in the F1 progeny. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

MOLECULAR DETECTION AND CLONING FOR RICKETTSIA-LIKE BACTERIA OF MILKY HAEMOLYMPH DISEASE OF SPINY LOBSTER Panulirus spp.

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Isti Koesharyani

2017-01-01

Full Text Available Spiny lobster (Panulirus homarus and Panulirus ornatus are important commodities for Indonesia. The aquaculture of lobster is susceptible for several diseases like parasite, fungi, bacteria, and virus. Among those diseases, milky haemolymph disease (MHD is often seen as a symptom to mass mortality occurred at lobster farms in Gerupuk Bay of Lombok. The purpose of this study was to determine the lobster diseases on cage culture in Gerupuk Bay of Lombok, West Nusa Tenggara. The study was undertaken from January to March 2015. Diseases status was determined by application of molecular plat-form, polymerase chain reaction (PCR with designation of specific primer for MHD (254F/R, 254F: 5’-CGA-GGA-CCA-GAG-ATG-GAC-CTT-3’ and 254R: 5’-GCT-CAT-TGT-CAC-CGC-CAT-TGT-3’ with PCR size product of 254 bp. and for cloned the pathogen was used TA-cloning Invitrogen for the DNA plasmid as positive control for other analysis. Several tissue samples i.e hepatopancreas, haemolymph, part of muscle hepatopancreas P. homarus and P. ornatus were taken from cage culture farms at Gerupuk Bay then preserved on 90% ethanol for further analysis by PCR and then the amplificated DNA were cloned into pCR®2.1 plasmid and transformed into competent E. coli. The result showed that almost all lobster samples from Gerupuk Bay were positive infected by MHD, as the results of PCR amplification whereas the band appeared at 254bp. Also MHD plasmid has been successfully cloned and will be used for further examination. Histopathologically in hepatopancreas infection have seen necrosis that contain numerous of rickettsia-like bacteria.

Comparison of real-time quantitative PCR and culture for the diagnosis of emerging Rickettsioses.

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Emmanouil Angelakis

Full Text Available BACKGROUND: Isolation of Rickettsia species from skin biopsies may be replaced by PCR. We evaluated culture sensitivity compared to PCR based on sampling delay and previous antibiotic treatment. METHODOLOGY/PRINCIPAL FINDINGS: Skin biopsies and ticks from patients with suspected Rickettsia infection were screened for Rickettsia spp. using qPCR, and positive results were amplified and sequenced for the gltA and ompA genes. Immunofluorescence for spotted fever group rickettsial antigens was done for 79 patients. All skin biopsies and only ticks that tested positive using qPCR were cultured in human embryonic lung (HEL fibroblasts using the centrifugation-shell vial technique. Patients and ticks were classified as definitely having rickettsioses if there was direct evidence of infection with a Rickettsia sp. using culture or molecular assays or in patients if serology was positive. Data on previous antibiotic treatments were obtained for patients with rickettsiosis. Rickettsia spp. infection was diagnosed in 47 out of 145 patients (32%, 41 by PCR and 12 by culture, whereas 3 isolates were obtained from PCR negative biopsies. For 3 of the patients serology was positive although PCR and culture were negative. Rickettsia africae was the most common detected species (n = 25, [17.2%] and isolated bacterium (n = 5, [3.4%]. The probability of isolating Rickettsia spp. was 12 times higher in untreated patients and 5.4 times higher in patients from our hometown. Rickettsia spp. was amplified in 24 out of 95 ticks (25% and we isolated 7 R. slovaca and 1 R. raoultii from Dermacentor marginatus. CONCLUSIONS/SIGNIFICANCE: We found a positive correlation between the bacteria copies and the isolation success in skin biopsies and ticks. Culture remains critical for strain analysis but is less sensitive than serology and PCR for the diagnosis of a Rickettsia infection.

Celulitis por citomegalovirus Cytomegalovirus cellulitis

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A. Ruiz Lascano

2002-12-01

Full Text Available Las lesiones cutáneas por citomegalovirus (CMV son infrecuentes y a menudo una manifestación tardía de una enfermedad sistémica, que generalmente anuncia un curso fatal. Comunicamos un caso de celulitis por CMV: una mujer de 70 años con trasplante renal efectuado 1 mes antes de la consulta, terapia inmunosupresora con ciclosporina A y metilprednisona. La paciente ingresó por fiebre, dolor e impotencia funcional en pierna derecha. Comprobamos la existencia de una placa de 8 por 4 cm eritematoedematosa. La tratamos con antibióticos sin mejoría, por lo que realizamos un estudio histopatológico de piel que mostró cambios citopáticos compatibles con infección por CMV. Los cultivos bacteriológicos y micológicos fueron negativos. La inmunohistoquímica específica para CMV y el estudio de reacción en cadena de la polimerasa (PCR de la biopsia de piel fueron positivas, al igual que la antigenemia. El tratamiento con ganciclovir produjo la mejoría del cuadro clínico. En la literatura revisada no hemos encontrado la celulitis como manifestación de enfermedad cutánea por CMV.Cutaneous lesions in CMV infection are rare, often a late manifestation of systemic infection, and usually herald a fatal course. A 70 year-old woman received a kidney transplantation one month before consulting and immunosuppressive therapy that included cyclosporine A and methylprednisone. She complained of fever, local pain in her right leg, and an erythematous and swelling plaque. She was treated with intravenous antibiotics without improvement. A skin biopsy was performed and the tissue obtained was sent for bacterial and fungal cultures as well as for histological examination. Cultures were negative. The biopsy showed CMV cytopathic changes. Immunoperoxidase staining was positive for CMV and polymerase chain reaction (PCR testing revealed CMV DNA. She was treated with ganciclovir with resolution of the lesion. CMV cellulitis is a rare cutaneous manifestation

Tendencia de la mortalidad por cáncer en Chile según diferencias por nivel educacional, 2000-2010

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Cristian A. Herrera Riquelme

2015-01-01

Full Text Available Objetivo. Caracterizar la tendencia de la mortalidad por cáncer en Chile según diferencias por nivel educacional en el período 2000-2010 en la población mayor de 20 años. Métodos. Cálculo de las tasas de mortalidad específica por cáncer ajustadas por edad para diferentes niveles educacionales (NE, para el período 2000-2010. Las tasas obtenidas se analizaron con un modelo de regresión de Poisson, calculando el índice de desigualdad relativa (IDR y el índice de desigualdad de la pendiente (IDP para cada año. Resultados. Se registraron 232 541 muertes por cáncer en el período 2000-2010. Los tipos de cáncer más frecuentes fueron de mama, estómago y vesícula biliar en mujeres; y estómago, próstata y pulmón en hombres. Las tasas de mortalidad por cáncer estandarizadas por edad fueron mayores en los NE más bajos, excepto para el de mama en mujer y el de pulmón en hombres. Las mayores diferencias se encontraron en el de vesícula biliar en mujeres y el de estómago en hombres, con mayores tasas de mortalidad específica de hasta 49 y 63 veces respectivamente, para NE bajo respecto al NE alto. Entre 2000 y 2010, las diferencias en mortalidad por NE se redujeron para todos los cánceres combinados en ambos géneros, mama en mujeres, y pulmón y estómago en hombres. Conclusiones. Durante el período estudiado, la mortalidad por cáncer en Chile estuvo fuertemente asociada al NE de la población. Esta información debe ser considerada al definir estrategias nacionales para reducir la mortalidad específica por cáncer en los grupos más desprotegidos.

ORF Alignment: NC_000963 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_000963 gi|15604438 >1xvqA 17 163 47 203 4e-07 ... ref|NP_220956.1| SCO2 PROTEIN PRECURSOR (sco2...) [Rickettsia prowazekii str. Madrid E] ... emb|CAA15032.1| SCO2 PROTEIN PRECURSOR (sco2...) ... [Rickettsia prowazekii] pir||F71663 sco2 protein ... precursor (sco2) RP587 - Rickettsia

Muerte materna por malaria grave por Plasmodium vivax

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Nancy Arróspide

Full Text Available Se presenta el caso de una mujer de 19 años con 29 semanas de gestación, procedente de Llumpe (Ancash con antecedentes de viajes a las localidades de Chanchamayo (Junín y Rinconada (Ancash. Ingresó al Hospital de Chacas (Ancash por presentar mal estado general, deshidratación, dificultad respiratoria, ictericia, sensación de alza térmica y dolor abdominal, tuvo reporte de: hemoparásitos 60% en frotis sanguíneo. Fue transferida al Hospital Ramos Guardia (Huaraz donde presentó mayor dificultad respiratoria, coluria, hematuria, disminución del débito urinario y reporte de Plasmodium (+, luego fue transferida al Hospital Cayetano Heredia (Lima donde ingresó a la Unidad de Cuidados Intensivos (UCI, con evolución a falla multiorgánica, óbito fetal y muerte materna. Se confirmó infección por Plasmodium vivax. Destacamos la importancia de mejorar nuestras capacidades de diagnóstico y manejo para brindar un tratamiento adecuado y oportuno.

Desenvolvimento de um kit de irrigação por microtubos com moto-bomba propulsionada por energia solar

OpenAIRE

Luiz Ricardo Sobenko

2016-01-01

O bombeamento de água por meio da energia solar vem se mostrando uma alternativa para localidades onde outras fontes de energia não estão disponíveis ou são limitadas. Torna-se interessante aliar essa alternativa a um sistema de irrigação que opera com vazão e pressão relativamente baixas, como a irrigação localizada por microtubos, possibilitando assim a obtenção de alta eficiência. No presente trabalho teve-se por objetivo dimensionar e avaliar um kit de irrigação por microtubos, alimentado...

Tendencia de la mortalidad por cáncer en Chile según diferencias por nivel educacional, 2000-2010

OpenAIRE

Cristian A. Herrera Riquelme; Lucy Kuhn-Barrientos; Roberto Rosso Astorga; Jorge Jiménez de la Jara

2015-01-01

Objetivo. Caracterizar la tendencia de la mortalidad por cáncer en Chile según diferencias por nivel educacional en el período 2000-2010 en la población mayor de 20 años. Métodos. Cálculo de las tasas de mortalidad específica por cáncer ajustadas por edad para diferentes niveles educacionales (NE), para el período 2000-2010. Las tasas obtenidas se analizaron con un modelo de regresión de Poisson, calculando el índice de desigualdad relativa (IDR) y el índice de desigualdad de la pendiente (ID...

Polución por material particulado fino (PM 2,5) incrementa las hospitalizaciones por insuficiencia cardiaca

OpenAIRE

Castro, Pablo; Vera, Jeanette; Cifuentes, Luis; Wellenius, Gregory; Verdejo, Hugo; Sepúlveda, Luis; Vukasovic, José Luis; Llevaneras, Silvana

2010-01-01

Antecedentes: Estudios recientes han reportado una asociación entre la contaminación ambiental por material particulado (PM) y el riesgo de hospitalizaciones de pacientes con insuficiencia cardiaca (IC). La región metropolitana de nuestro país constituye un área geográfica en la cual la contaminación es especialmente relevante, asociándose a incrementos periódicos en la morbimortalidad por causa respiratoria. Sin embargo el efecto de la polución por PM en la morbilidad de pacientes con IC no ...

Enfermedad de Hirschsprung

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Gonzalo López Escobar

1990-04-01

Full Text Available

Definición
La enfermedad de Hirschsprung, megacolon congénito o agangliónico, o Aganglionosis Intestinal Congénita, es una anomalía caracterizada por la ausencia congénita de células ganglionares del sistema parasimpático de los piejos intermientéricos de Auerbach, situado entre las capas musculares, circular y longitudinal, y el submucoso de Meissner; con conducción inefectiva del peristaltismo, ocasionando obstrucción funcional (24, 37, 65, 82, 120, 130, 134.

Historia
La descripción del megacolon congénito fue hecha por e! pediatra danés, HARALD HIRSCHSPRUNG, en 1886, en el Congreso de Pediatría de Berlín, donde describió dos casos, un niño de 7, Y otro de II meses de edad, quienes murieron, y al practicar la autopsia observó “dilatación enorme del colon”, con fecalomas en su interior y ulceraciones de la mucosa. Su informe apareció en la literatura médica un año después, en 1887.

Sin embargo, la prime¡a anotación de esta alteración se le asigna a FREDERICK RUYSCH, quien en 1691, publicó en Amsterdam, en la Revista “Observationum AnatomiciChirurgicarum Centuria”, la descripción de la autopsia de una niña de cinco años quien había sido tratada por dolor y distensión abdominal, y flatos, finalmente murió; al abrir el cadáver pudo apreciar “todas las vísceras abdominales cubiertas por el colon distendido desde el recto”, descartó lo demás por considerarlo normal. (67, 129.

En 1825, Parry hizo la primera descripción en la literatura inglesa, de un joven de 23 años quien sufría de estreñimiento. (69, 129.

En 1829, Billar, informó dos casos similares.

En 1867, Lewitt, en Ann Arbor, Michigan, informó el primer caso en la literatura americana, de un joven de 21 años, con dolores abdominales y distensión, y al practicar el tacto anal encontró gran masa que ocupaba toda la pelvis, al parecer un fecaloma. (129.

RICKETTSIAL DISEASES: RISK FOR INDONESIA

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Allen L. Richards

2012-09-01

Full Text Available Penyakit Rickettsia bersifat endemik hampir di seluruh bagian dunia, dan begitu juga di Indonesia. Termasuk dalam penyakit-penyakit rickettsia adalah tifus epidemik, tifus murine, "scrub typhus," dan "spotted fever." Tifus epidemik, yang ditularkan kepada manusia melalui tuma pada tubuh manusia, dan dapat menyebabkan sakit berat dan kematian.   Tifus murine (tifus endemik, bersumber pada pinjal hewan, merupakan penyakit yang mirip tifus epidemik, tetapi dengan gejala-gejala yang lebih ringan dan jarang menyebabkan kematian. "Scrub typhus", merupakan penyakit yang dapat ringan sampai berat dan dapat membahayakan hidup, ditularkan kepada manusia melalui gigitan tungau yang belum dewasa yang dikenal sebagai "chigger". "Spotted fever: (demam yang disertai dengan bintik-bentik pada kulit, disebabkan karena terinfeksi oleh salah satu dari berbagai spesies rickettsia dari kelompok "spotted fever", dan ditularkan kepada manusia oleh pejamu (hospes vertebrata melalui gigitan caplak (tick yang terinfeksi. Penyakit yang disebabkan oleh organisma yang menyerupai rickettsia (rickettsia-like organism adalah: "Q fever", yaitu penyakit yang akut atau kronis yang diduga ditularkan secara alamiah akibat terhirup oleh partikel udara yang terinfeksi Coxiella burnetti sejenis bakteri yang sangat resisten terhadap upaya menonaktifkannya secara kimiawi dan fisik. Bartonellosis atau penyakit Carrion, ditemukan pada daerah dengan ketinggian sedang di Andes, Amerika Selatan. Penyakit ini ditularkan oleh lalat pasir (sand flies. "Trench fever", mirip dengan tifus epidemik, ditularkan kepada manusia oleh tuma; penyakit ini sembuh sendiri. Penyakit garutan kucing (Cat-scratch disease, disebabkan oleh infeksi Bartonella henselae di tempat gigitan atau garutan kucing rumah yang merupakan hospes. Demam sennetsu, merupakan penyakit yang dapat sembuh sendiri dan hanya ditemukan di Jepang dan Malaysia. Pengobatan dengan tetrasiklin atau kloramfenikol untuk penyakit Rickettsia

Síndrome de Munchausen por mandato

OpenAIRE

Esteban, Miguel A.; Pérez, Miriam R.; Bracco, Anahí

2006-01-01

El Síndrome de Munchausen por mandato, "un trastorno ficticio, por el cual la enfermedad del niño es inducida, promovida o provocada por la persona más próxima a él, generalmente su madre", es todavía mal conocido y su génesis imperfectamente comprendida. Esta comunicación está destinada a esclarecer al pediatra esta patología, con elevada morbilidad y secuelas, como así también de altísima mo...

DESGASTE POR ABRASIÓN DEL ACERO API 5L X65 REVESTIDO CON NIOBIO POR ASPERSIÓN TÉRMICA A PLASMA Y CON INCONEL 625 POR SOLDADURA

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JOSE MATOS

2012-01-01

Full Text Available El objetivo de este trabajo fue evaluar y caracterizar el comportamiento mecánico en desgaste del acero API 5L X65, revestido con niobio en comparación al desempeño del revestimiento de la aleación de inconel 625 empleados en la industria de petróleo y gas. El revestimiento de niobio fue obtenido por el proceso de aspersión térmica a plasma de arco no transferido y el revestimiento inconel 625 por soldadura con electrodo revestido. La resistencia al desgaste por abrasión fue evaluada según la norma Petrobras N-2568, en un tribómetro CTER, la rugosidad y el volumen de material desgastado se determinó a través de perfilometría y la dureza de los revestimientos por microscopia Vickers. Los revestimientos obtenidos fueron caracterizados respecto a su morfología por microscopia electrónica de barrido (MEB y microscopía óptica (MO. La mayor dureza del revestimiento con niobio obtenido puede haber contribuido a reducir la tasa de desgaste en comparación con el revestimiento de inconel 625.

Mecanismos biopatológicos da metastização ganglionar no carcinoma gástrico. Implicações para a cirurgia radical

OpenAIRE

Fradique, António Amável Caldeira

2009-01-01

RESUMO A constatação de que o carcinoma gástrico continua a ser a segunda causa de morte por doença oncológica no mundo em geral e em particular em Portugal, assim como a verificação da elevada incidência e letalidade no nosso país, justifica uma particular atenção a esta doença. Apesar de avanços recentes na acção adjuvante e neo-adjuvante de terapêuticas não cirúrgicas, com algumas referências a melhorias na sobrevivência, estas terapêuticas não têm eficácia curativa. Sendo assim, a ...

CARACTERÍSTICAS DA VIOLÊNCIA SEXUAL SOFRIDA POR CRIANÇAS ASSISTIDAS POR UM PROGRAMA DE APOIO

OpenAIRE

KELLY LINHARES VASCONCELOS; ADRIANA GOMES NOGUEIRA FERREIRA; ELIANY NAZARÉ OLIVEIRA; DANIELLE D\\u2019ÁVILA SIQUEIRA; PATRÍCIA NEYVA DA COSTA PINHEIRO

2010-01-01

En Brasil, las estadísticas de la violencia sexual contra niños están lejos de reflejar la verdadera realidad actual debido a la baja notificación de los casos. La finalidad de este estudio fue caracterizar el abuso sexual sufrido por niños asistidos por el Programa Sentinela y el perfil del agresor, en Sobral-Ceará, en el periodo que va del 2002 al 2006. La muestra no probabilística intencional fue compuesta por 50 víctimas de abuso sexual y de las mismas, el 66% es del sexo femenino, con pr...

Abdome agudo por obstrução por ileobiliar

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Márcia Cristina de Alencastro

Full Text Available OBJETIVO: descrever a experiência na abordagem dos doentes com abdome agudo por obstrução por IB, desde o diagnóstico até o tratamento definitivo. MÉTODOS: estudo retrospectivo incluindo todos os casos de IB tratados em um período de 23 anos. De acordo com a abordagem cirúrgica realizada, os pacientes foram divididos em dois grupos (1 enterolitotomia com colecistectomia no segundo momento; e (2 enterolitotomia, colecistectomia e abordagem da fístula. RESULTADOS: Doze pacientes foram incluídos, sendo 11 mulheres (91,6%, com média de idade de 72,2 anos. Todos os pacientes apresentavam doenças associadas, principalmente hipertensão arterial sistêmica (75%. Dois pacientes não apresentavam sintomas significativos de obstrução intestinal. O diagnóstico de IB foi realizado em seis pacientes (50% antes da laparotomia. O grupo 1 foi constituído de oito pacientes e o grupo 2 de quatro, e a morbidade foi, respectivamente, 33,3% e 8,3%. A mortalidade foi 16,6% (um paciente de cada grupo. CONCLUSÃO: O manejo do IB deve ser individualizado. O tratamento da obstrução mediante remoção do cálculo biliar por enterotomia proximal é a escolha inicial para o tratamento do IB. A colecistectomia e a correção da fístula bilioentérica podem ser realizadas juntamente com a remoção do cálculo, no entanto, em pacientes com comorbidades significativas, esses procedimentos devem ser realizados posteriormente.

Disposal of Hospital Wastes Containing Pathogenic Organisms

Science.gov (United States)

1979-09-01

virus African swine fever virus Besnoitia besnoiti Borna disease virus Bovine infectious petechial fever virus Camel pox virus Ephemeral fever virus...Sindbis virus Tensaw virus Turlock virus Vaccinia virus Varicella virus Vole rickettsia Yellow fever virus, 17D vaccinL strain 163 Class 3 AlastruLn...Rickettsia - all species except Vole rickettsia when used for transmission or animal inoculation experiments Vesicular stomatitis virus Yellow fever virus

Uso das diretrizes para tratamento da úlcera por pressão por enfermeiros de um hospital geral

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Elaine Maria Leite Rangel

2009-03-01

Full Text Available Este estudo objetivou identificar a freqüência do uso das diretrizes para o tratamento da úlcera por pressão(UP por enfermeiros de um hospital geral no interior do estado de São Paulo. É transversal de caráterdescritivo com análise quantitativa de dados. Amostra de 25 enfermeiros. Para a coleta de dados utilizou-se uminstrumento, construído a partir das diretrizes para o tratamento da UP. As questões foram relacionadas aostipos de intervenções usadas pelos enfermeiros para o tratamento da UP em estágio I, II, com necrose e comtecido de granulação. Para UP em estágio I, 24 (96% enfermeiros sempre realizavam a mudança de decúbito.Nas úlceras em estágio II a utilização de óleos vegetais na ferida era realizada sempre por 10 (40%enfermeiros e o curativo de hidrocolóide nunca era utilizado por 12 (57,1% enfermeiros. Em UP com necrose alimpeza com povidine era realizada por 4 (17,4% enfermeiros às vezes. Para o desbridamento, 16 (64% àsvezes utilizavam papaína e 15 (71,4% às vezes utilizavam colagenase. Em úlceras com tecido de granulaçãosempre era utilizado o soro fisiológico por 25 (100% enfermeiros. Houve variação nas práticas para otratamento da UP e falta de adesão às diretrizes.

Mortalidad por causas externas en Medellín, 1999-2006

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Doris Cardona Arango

2008-01-01

Full Text Available Caracterizar el comportamiento de la mortalidad por causas externas en la ciudad de Medellín, Colombia, entre 1999-2006, según sexo, edad y causa básica de muerte fue el objetivo de este estudio descriptivo longitudinal, con fuente de información secundaria de 22 128 registros de defunción por causas externas. El análisis realizado es univariado y bivariado por sexo, grupos de edad y causa de muerte. Las causas externas registradas en el periodo fueron: 72.9 por ciento por homicidio; 15.3 por ciento, accidente de transporte; 7.3 por ciento, traumatismos; 4.2 por ciento, por suicidio, y por otras causas, 0.4 por ciento. La mayor tasa de mortalidad se presentó en el grupo de edad de 20 a 24 años (27.6 por cien mil habitantes, hecho que merece especial consideración por las implicaciones sociales, familiares y laborales que representa el fallecimiento de una persona en su etapa productiva.

Adenoma tiroidiano con sospecha de degeneración maligna

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Manuel José Luque

1944-11-01

III El autor describe la intervención quirúrgica y anota los hallazgos del acto operatorio. Se hizo una estirpación meticulosa de todas las formaciones ganglionares. IV Transcribe día a día el post operatorio y termina con unas breves consideraciones sobre la degeneración neoplásica del cuerpo tiroides.

Apendicitis por Paracoccidioides brasiliensis

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Ana Beatriz MUÑOZ URRIBARRI

2006-01-01

Full Text Available La paracoccidioidomicosis es la micosis más prevalente en Sudamérica. La forma aguda afecta el sistema fagocítico mononuclear de niños y personas inmunocomprometidas. El compromiso gastrointestinal es frecuente y su patogenia implica diseminación hematógena y linfática. La linfadenomegalia abdominal causa obstrucción intestinal y abdomen agudo. En este artículo damos a conocer el caso de un niño con compromiso gastrointestinal por apendicitis. Este es el primer caso reportado de apendicitis por esta patología. (Rev Med Hered 2006;17:58-60.

[Rickettsiosis after tick bite: A subtle clinic picture on many occasions, we must be vigilant].

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Monterde-Álvarez, Maria Laura; Calbet-Ferré, Clara; Rius-Gordillo, Neus; Pujol-Bajador, Isabel; Ballester-Bastardie, Frederic; Escribano-Subías, Joaquín

2017-02-01

Rickettsia diseases are a group of tick-borne transmitted diseases, classified into 2 large groups: spotted fevers and typhus fevers. In addition, a new condition has been described recently, known as tick-borne lymphadenopathy. A retrospective series is presented of paediatric cases of rickettsia diseases diagnosed in 2013 and 2014. A total of 8 patients were included, of which 2 of them were diagnosed as Mediterranean spotted fever, and 6 as tick-borne lymphadenopathy. Rickettsia slovaca, Rickettsia sibirica mongolitimonae, and Rickettsia massiliae were identified in 3 of them. Aetiology, clinical features and treatment carried out in each of them are described. The interest of these cases is that, although most have a benign course, the high diagnostic suspicion and early treatment seem to be beneficial for its outcome. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Almost there: transmission routes of bacterial symbionts between trophic levels.

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Elad Chiel

Full Text Available Many intracellular microbial symbionts of arthropods are strictly vertically transmitted and manipulate their host's reproduction in ways that enhance their own transmission. Rare horizontal transmission events are nonetheless necessary for symbiont spread to novel host lineages. Horizontal transmission has been mostly inferred from phylogenetic studies but the mechanisms of spread are still largely a mystery. Here, we investigated transmission of two distantly related bacterial symbionts--Rickettsia and Hamiltonella--from their host, the sweet potato whitefly, Bemisia tabaci, to three species of whitefly parasitoids: Eretmocerus emiratus, Eretmocerus eremicus and Encarsia pergandiella. We also examined the potential for vertical transmission of these whitefly symbionts between parasitoid generations. Using florescence in situ hybridization (FISH and transmission electron microscopy we found that Rickettsia invades Eretmocerus larvae during development in a Rickettsia-infected host, persists in adults and in females, reaches the ovaries. However, Rickettsia does not appear to penetrate the oocytes, but instead is localized in the follicular epithelial cells only. Consequently, Rickettsia is not vertically transmitted in Eretmocerus wasps, a result supported by diagnostic polymerase chain reaction (PCR. In contrast, Rickettsia proved to be merely transient in the digestive tract of Encarsia and was excreted with the meconia before wasp pupation. Adults of all three parasitoid species frequently acquired Rickettsia via contact with infected whiteflies, most likely by feeding on the host hemolymph (host feeding, but the rate of infection declined sharply within a few days of wasps being removed from infected whiteflies. In contrast with Rickettsia, Hamiltonella did not establish in any of the parasitoids tested, and none of the parasitoids acquired Hamiltonella by host feeding. This study demonstrates potential routes and barriers to horizontal

Tatuaje por amalgama. Reporte de un caso

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Luis Fang Mercado

2012-01-01

Full Text Available El tatuaje por amalgama se origina por el depósito en el tejido conectivo subepitelial de fragmentos de amalgama resultado de procedimientos iatrogénicos por parte del operador. La profundidad a la que se encuentren albergados los residuos de este material influye en la presentación clínica de las lesiones. Radiográficamente se pueden identificar los fragmentos mientras tengan diámetros razonables; histológicamente se pueden observar las partículas de amalgama como gránulos oscuros, sólidos e irregulares dispuesto entre los haces de colágeno y vasos sanguíneos. Este artículo refiere el caso clínico de un paciente que presentó pigmentación por amalgama en mucosa vestibular, originada por una porción de amalgama usada como material obturador en una apicectomía del 11 realizada con anterioridad. Teniendo en cuenta las consideraciones clínicas y radiográficas se optó por realizar una segunda apicectomía con obturación retrógrada con MTA del 11. Durante el procedimiento quirúrgico se cureteó y adelgazó la cara interna del colgajo mucoperióstico para tratar de disminuir el grado de pigmentación.

La pintura vista por un pintor joven

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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.

Experiência inicial com terapia por pressão negativa por instilação em feridas complexas

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Dimas André Milcheski

Full Text Available RESUMO Objetivo: relatar a experiência inicial com a terapia por pressão negativa por instilação em feridas complexas infectadas ou contaminadas. Métodos: a terapia por pressão negativa por instilação utilizada foi o V.A.C. Ulta com instilação Veraflo (Kinetic Concepts, Inc. O modo de operação foi contínuo com pressão sub-atmosférica ajustada em 125 mmHg por duas horas e instilação entre as pausas. O tempo de instilação foi de 20 minutos (tempo de contato do agente tópico com a ferida e a substância instilada foi solução salina padrão a 0,9%. Após obtenção de preparo adequado da ferida, ela foi coberta com enxerto ou retalho. Resultados: foram operados dez pacientes com feridas complexas contaminadas ou infectadas. O número médio de trocas da TPNi foi 1,4, o número médio total de cirurgias foi de 2,4, o intervalo até a cobertura da ferida foi de 6,3 dias e o intervalo até a alta foi de 11,4 dias. Conclusão: a comparação da terapia por pressão negativa por instilação com dois estudos prévios (controle histórico evidenciou um tempo de internação menor, favorecendo a TPNi. Este estudo teve um caráter inicial, fazendo-se necessário conduzir um trabalho randomizado e controlado para confirmar a eficácia desta terapia e verificar a sua custo-efetividade.

Neuropatia experimental por DDT: análise de nervo por microdissecção de fibras

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Edison Matos Nóvak

1984-09-01

Full Text Available Estudou-se o nervo gênito-femural do rato albino submetido a intoxicação crônica por DDT, administrado por 180 dias na dose de 5 mg/kg de peso via oral. Os resultados mostraram proporção anormal de fibras tipo C, sendo sugerido ocorrer degeneração tipo axonal determinada pelo DDT.

Revisão radiológica de 173 casos consecutivos de paracoccidioidomicose Radiological review of 173 consecutive cases of paracoccidioidomycosis

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Henrique Simão Trad

2006-06-01

Full Text Available OBJETIVO: Revisar e determinar a incidência dos achados radiológicos mais importantes da paracoccidioidomicose, e verificar as possíveis variantes de suas apresentações. MATERIAIS E MÉTODOS: Foram revistos 173 casos consecutivos de paracoccidioidomicose, atendidos no período de 1970 a 1980. Os estudos radiológicos direcionados a cada caso foram reanalisados por no mínimo dois radiologistas experientes. RESULTADOS: Foram encontrados 94 casos de acometimento pulmonar isolado e 38 de acometimento pulmonar associado a lesões ganglionares, viscerais, ósseas e à tuberculose. Sem envolvimento pulmonar foram encontrados 41 casos, com lesões intestinais, viscerais, ósseas ou combinadas. Os principais achados radiológicos da forma pulmonar foram opacidade intersticial reticular e nodular bilateral, seguida por consolidação, também bilateral. As formas visceral e intestinal apresentaram lesões predominantes no fígado, jejuno e íleo. Na forma ganglionar houve predominância do comprometimento difuso abdominal e periférico, e no ósseo, áreas de lise principalmente em ossos longos e clavícula. CONCLUSÃO: A paracoccidioidomicose é doença granulomatosa comum no Brasil, acometendo principalmente o pulmão, tendo como porta de entrada a inalação dos esporos do fungo. Outras formas desta doença, menos freqüentes ou raras, devem ser permanentemente lembradas no diagnóstico diferencial.OBJECTIVE: To determine the incidence of most significant radiological findings of paracoccidioidomycosis and to verify its possible variants. MATERIALS AND METHODS: One hundred and seventy-three cases of paracoccidioidomycosis presented between 1970 and 1980 were reviewed, including their radiological workup reanalysis by at least two experienced radiologists. RESULTS: Ninety-four cases were pulmonary only and 38 were pulmonary associated with ganglial, visceral and osseous lesions or in association with tuberculosis. There was no pulmonary

Tuberculosis extrapulmonar: revisión de 102 casos en el Hospital Universitario San Jorge de Pereira, 2000-2004.

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William Arciniegas

2006-03-01

Full Text Available Introducción. La tuberculosis continúa siendo un problema de salud pública en el mundo. Es necesario conocer su magnitud en cada institución, la oportunidad en el diagnóstico y la utilización de recursos. Objetivo. Determinar las localizaciones y caracterizar la tuberculosis extrapulmonar desde el punto de vista epidemiológico, clínico, microbiológico, de diagnóstico y de costos hospitalarios de los pacientes egresados en un hospital estatal de III nivel. Materiales y métodos. Estudio descriptivo retrospectivo realizado entre el 2000 y el 2004 mediante la revisión de historias clínicas y archivos de laboratorio de pacientes egresados con diagnóstico de tuberculosis extrapulmonar del Hospital Universitario San Jorge de Pereira, Colombia. Resultados. Se encontraron 102 casos, con promedio de edad de 31,6 años, de los cuales el 62,7% correspondía a hombres. El 70,6% procedía del área urbana y el 59,6% presentó síntomas clínicos mayores a los 15 días de evolución. La forma más frecuente de presentación fue la pleural, con 47 casos, seguida de la meníngea con 19, la ganglionar con 13, la peritoneal con 5, la miliar con 4, la genitourinaria con 4, la faríngea con 4, la articular con 3, la ósea con 2 y la pericárdica con 1 caso. Los métodos de diagnóstico más utilizados fueron la biopsia en 68 casos (66,6%, el clínico en 28 (27,4%. Por medio de baciloscopia con coloración de Zielh Neelsen, se diagnosticó el 3,9%, y con el cultivo de Mycobacterium tuberculosis, el 5,8%. El tiempo de estancia hospitalaria promedio fue de 13 días y el costo promedio fue de $5'784.603 por caso. Fallecieron 15 pacientes, de los cuales el 60% se asoció con sida, y 53,3% con meningitis. Conclusión. Las localizaciones más frecuentes fueron la pleural, la meníngea y la ganglionar. El principal método de diagnóstico fue la biopsia. La estancia prolongada se relacionó con demora en el diagnóstico y sida. La mortalidad fue mayor en los

Ptose palpebral causada por Paquidermoperiostose

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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.

Paciente VIH positivo con tuberculosis sistémica y lesiones osteolíticas de la calvaria, semejando mieloma múltiple

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Victor Mechán

2010-07-01

Full Text Available Varón de 33 años, soltero, sin ocupación fija, promiscuo, con historia de relaciones homosexuales, ingesta crónica de alcohol, consumo de tabaco, marihuana, pasta básica y clorhidrato de cocaína, desde los 18 años. Infectado por el virus de la inmunodeficiencia humana, recibía tratamiento irregular con terapia antirretroviral de gran actividad (Targa entre 2006 y 2008, regularizada en los últimos 12 meses. Por presentar bacilo ácido alcohol resistente (BAAR pansensible en esputo, inició en junio 2008 tratamiento antituberculoso [2RHZE/4(HR2], retirándosele la medicación 6 meses después por presentar BAAR pulmonar negativo. En marzo de 2009, percibió dolor lumbar intenso, dificultad para caminar, hipertrofia de ganglios cervicales, tos, fiebre. Un cultivo de secreción ganglionar cervical descubrió M. tuberculosis resistente a rifampicina. La imagenología mostró lesiones osteolíticas múltiples en cráneo y vértebras dorsolumbares y tumefacciones renitentes en cuero cabelludo, antebrazo derecho y parrilla costal izquierda. Tras descartarse mieloma múltiple y metástasis cancerosas, se añadió tratamiento antituberculosis multidrogo resistente al Targa, notándose dos meses después involución de las tumefacciones renitentes, de la fiebre y mejoría del estado general. Tras 16 meses de tratamiento supervisado, el paciente aumentó 7 kg de peso, habiendo desaparecido la sintomatología que presentaba. Se discute la fisiopatología de las lesiones osteolíticas cráneo-vertebrales en un paciente con coinfección por el virus de la inmunodeficiencia humana y tuberculosis.

Suppression of cytochrome P450 reductase (POR) expression in hepatoma cells replicates the hepatic lipidosis observed in hepatic POR-null mice.

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Porter, Todd D; Banerjee, Subhashis; Stolarczyk, Elzbieta I; Zou, Ling

2011-06-01

Cytochrome P450 reductase (POR) is a microsomal electron transport protein essential to cytochrome P450-mediated drug metabolism and sterol and bile acid synthesis. The conditional deletion of hepatic POR gene expression in mice results in a marked decrease in plasma cholesterol levels counterbalanced by the accumulation of triglycerides in lipid droplets in hepatocytes. To evaluate the role of cholesterol and bile acid synthesis in this hepatic lipidosis, as well as the possible role of lipid transport from peripheral tissues, we developed a stable, small interfering RNA (siRNA)-mediated cell culture model for the suppression of POR. POR mRNA and protein expression were decreased by greater than 50% in McArdle-RH7777 rat hepatoma cells 10 days after transfection with a POR-siRNA expression plasmid, and POR expression was nearly completely extinguished by day 20. Immunofluorescent analysis revealed a marked accumulation of lipid droplets in cells by day 15, accompanied by a nearly 2-fold increase in cellular triglyceride content, replicating the lipidosis seen in hepatic POR-null mouse liver. In contrast, suppression of CYP51A1 (lanosterol demethylase) did not result in lipid accumulation, indicating that loss of cholesterol synthesis is not the basis for this lipidosis. Indeed, addition of cholesterol to the medium appeared to augment the lipidosis in POR-suppressed cells, whereas removal of lipids from the medium reversed the lipidosis. Oxysterols did not accumulate in POR-suppressed cells, discounting a role for liver X receptor in stimulating triglyceride synthesis, but addition of chenodeoxycholate significantly repressed lipid accumulation, suggesting that the absence of bile acids and loss of farnesoid X receptor stimulation lead to excessive triglyceride synthesis.

Consanguinidad por isonimia en Salta

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Albeza, María V.

2007-01-01

Full Text Available Se estimó el coeficiente de parentesco por isonimia para localidades de la Puna, Valle Calchaquí y Valle de Lerma, a fin de evaluar diferentes factores evolutivos que podrían estar afectando la composición genética de la población. A partir de los apellidos de las parejas consignadas en fuentes primarias de información, se estimó la isonimia conyugal o marital, el coeficiente total Ft y sus componentes Fr (inbreeding azaroso y Fn (inbreeding no azaroso. De las localidades estudiadas, en la Puna se ha detectado sólo una pareja isónima en una de ellas, en el Valle Calchaquí, tres y ninguna en el Valle de Lerma. Tanto en el Valle Calchaquí como en el de Lerma, se han estimado valores negativos de Ft, y en la Puna se registran los valores más elevados. En las localidades estudiadas no se cumple el supuesto de transmisión patrilineal de apellidos por lo que los valores de Fr y por ende de Ft podrían estar subestimados. Es por ello que sería necesario contar con información desde otras vertientes metodológicas para corroborar, complementar y manejar cuidadosamente el análisis de los datos y las conclusiones que se obtienen.

Nefrectomía simple por puerto único (LESS) asistida por robot (da Vinci)

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CASTILLO C,OCTAVIO A; VIDAL M,IVAR; SEPÚLVEDA T,FRANCISCO

2011-01-01

Introducción: La cirugía mínimamente invasiva en urología avanza rápidamente y la cirugía laparo-endoscópica a través de puerto único (LESS) no es la excepción. Esta técnica por vía laparoscópica presenta mucha dificultad y requiere de un cirujano laparoscópico experimentado debido a la falta de triangulación y el cruce de los instrumentos. Los beneficios del sistema quirúrgico da Vinci® han sido introducidos recientemente en LESS. Presentamos dos casos de nefrectomía LESS asistida por robot....

Análisis de costos por ausentismo laboral atribuibles a licencias médicas por enfermedad. Hospital Nacional Arzobispo Loayza 2015

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Jave Escalante, Gladys Lizeth

2015-01-01

Determina el costo generado por el ausentismo laboral atribuible a licencias médicas por enfermedad en el Hospital Nacional Arzobispo Loayza 2015. METODOLOGÍA: Estudio no experimental. La muestra estuvo conformada por 118 médicos asistenciales y personal de enfermería. Para el análisis de los costos se utilizó el costo de tiempo perdido del paciente, ingresos dejados de percibir por el hospital y descuento económico al trabajador. Además se realizó un análisis económico y de sensibilidad. ...

Indice por Materias

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Montoya H Luz Marina

1982-09-01

Full Text Available Un índice es una lista de palabras o frases indicadores asociados que permite la ubicación de material al interior de un libro o una publicación, en este caso será por el nombre de la materia.

AcEST: DK952622 [AcEST

Lifescience Database Archive (English)

Full Text Available Q Sbjct: 306 SYAPDGRQITFNSDRGGAQQ 325 >sp|A8F168|TOLB_RICM5 Protein tolB OS=Rickettsia massiliae (strain Mtu...ein tolB OS=Rickettsia massiliae (strai... 37 0.047 sp|Q4UM77|TOLB_RICFE Protein tolB OS=Rickettsia felis GN...0.021 sp|Q2RVF0|TOLB_RHORT Protein tolB OS=Rhodospirillum rubrum (stra... 38 0.036 sp|A8F168|TOLB_RICM5 Prot

Mortalidad intrahospitalaria por accidente cerebrovascular

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Federico Rodríguez Lucci; Virginia Pujol Lereis; Sebastián Ameriso; Guillermo Povedano; María F. Díaz; Alejandro Hlavnicka; Néstor A. Wainsztein; Sebastián F. Ameriso

2013-01-01

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 Str...

NCBI nr-aa BLAST: CBRC-DSIM-01-0041 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-DSIM-01-0041 ref|ZP_00141975.1| phosphatidate cytidylyltransferase [Rickettsia sibi...rica 246] gb|EAA25384.1| phosphatidate cytidylyltransferase [Rickettsia sibirica 246] ZP_00141975.1 0.009 26% ...

Ticks and tick-borne pathogens and putative symbionts of black bears (Ursus americanus floridanus) from Georgia and Florida.

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Yabsley, Michael J; Nims, Todd N; Savage, Mason Y; Durden, Lance A

2009-10-01

Ticks were collected from 38 black bears (Ursus americanus floridanus) from northwestern Florida (n = 18) from 2003 to 2005 and southern Georgia (n = 20) in 2006. Five species (Amblyomma americanum, A. maculatum, Dermacentor variabilis, Ixodes scapularis, and I. affinis) were collected from Florida bears, and 4 species (A. americanum, A. maculatum, D. variabilis, I. scapularis) were collected from bears in Georgia. Ixodes scapularis was the most frequently collected tick, followed by D. variabilis, A. americanum, A. maculatum, and I. affinis. The collection of I. affinis from a Florida bear represents a new host record. A subset of ticks was screened for pathogens and putative symbionts by polymerase chain reaction (PCR). The zoonotic tick-borne pathogens Ehrlichia chaffeensis and Rickettsia parkeri were detected in 1 of 23 (4.3%) A. americanum and 1 of 12 (8.3%) A. maculatum, respectively. The putative zoonotic pathogen "Rickettsia amblyommii" was detected in 4 (17.4%) A. americanum and 1 (8.3%) A. maculatum. Other putative symbiotic rickettsiae detected included R. bellii and R. montanensis in D. variabilis, a Rickettsia cooleyi-like sp. and Rickettsia sp. Is-1 in I. scapularis, and Rickettsia TR39-like sp. in I. scapularis and A. americanum. All ticks were PCR-negative for Anaplasma phagocytophilum, Panola Mountain Ehrlichia sp., E. ewingii, Francisella tularensis, and Borrelia spp.

CARACTERÍSTICAS DA VIOLÊNCIA SEXUAL SOFRIDA POR CRIANÇAS ASSISTIDAS POR UM PROGRAMA DE APOIO

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KELLY LINHARES VASCONCELOS

2010-01-01

Full Text Available En Brasil, las estadísticas de la violencia sexual contra niños están lejos de reflejar la verdadera realidad actual debido a la baja notificación de los casos. La finalidad de este estudio fue caracterizar el abuso sexual sufrido por niños asistidos por el Programa Sentinela y el perfil del agresor, en Sobral-Ceará, en el periodo que va del 2002 al 2006. La muestra no probabilística intencional fue compuesta por 50 víctimas de abuso sexual y de las mismas, el 66% es del sexo femenino, con predominio de rango de edad entre 8-12 años incompletos, (58%; en el 36% de los casos los padres están separados, siendo la madre la principal responsable por la familia (62%. La mayoría de los agresores es del sexo masculino (78%. En el ambiente fuera de la familia los agresores son conocidos o amigos de la familia (14%; dentro del seno familiar el padrastro es identificado como siendo el agresor más frecuente (18%. Los datos destacan características similares a las de otros estudios, definiendo una cierta igualdad en este tipo de violencia.

Rickettsioses do grupo das febres maculosas em viajantes argentinos

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Martino Olindo

2001-01-01

Full Text Available Durante o ano de 1996, foram atendidos no ambulatório de medicina de viajantes, quatro pacientes procedentes do sul da África com diagnóstico de rickettsiose. Todos eles apresentaram febre, dor de cabeça e presença de escara cutânea. Às 48 horas de iniciado o quadro, um dos pacientes evidenciou uma erupção máculo-papular, enquanto que os restantes desenvolveram um exantema vesicular e crostoso. A reação de Weil-Felix mostrou-se negativa e a sorologia para Rickettsia conorii por imunofluorescência foi positiva em todos os casos. Nenhum dos pacientes recordava haver sofrido picada de insetos ainda que tenham permanecido ou transitado por pastagens em regiões agrestes. Todos receberam tratamento com doxiciclina com evolução clínica satisfatória.

Rickettsioses in Latin America, Caribbean, Spain and Portugal

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Marcelo B. Labruna

2011-05-01

Full Text Available Data on genus and infectious by Rickettsia were retrospectively compiled from the critical review literature regarding all countries in Latin America, Caribbean islands, Portugal and Spain. We considered all Rickettsia records reported for human and/or animal hosts, and/or invertebrate hosts considered being the vector. In a few cases, when no direct detection of a given Rickettsia group or species was available for a given country, the serologic method was considered. A total of 13 Rickettsia species have been recorded in Latin America and the Caribbean. The species with the largest number of country confirmed records were Rickettsia felis (9 countries, R. prowazekii (7 countries, R. typhi (6 countries, R. rickettsii (6 countries, R. amblyommii (5 countries, and R. parkeri (4 countries. The rickettsial records for the Caribbean islands (West Indies were grouped in only one geographical area. Both R. bellii, R. akari, and Candidatus ‘R. andeane’ have been recorded in only 2 countries each, whereas R. massiliae, R. rhipicephali, R.monteiroi, and R. africae have each been recorded in a single country (in this case, R. africae has been recorded in nine Caribbean Islands. For El Salvador, Honduras, and Nicaragua, no specific Rickettsia has been reported so far, but there have been serological evidence of human or/and animal infection. The following countries remain without any rickettsial records: Belize, Venezuela, Guyana, Surinam, and Paraguay. In addition, except for a few islands, many Caribbean islands remain without records. A total of 12 Rickettsia species have been reported in Spain and Portugal: R. conorii, R. helvetica, R. monacensis, R. felis, R. slovaca, R. raoultii, R. sibirica, R. aeschlimannii, R. rioja, R. massiliae, R. typhi, and R. prowazekii. Amongst these Rickettsia species reported in Spain and Portugal, only R. prowazekii, R. typhi, R. felis, and R. massiliae have also been reported in Latin America. This study summarizes

Mammary neoplasm inflammatory: clinic presentation: combined treatment value

International Nuclear Information System (INIS)

Viola Alles, A.; Sabini Gaye, G.; Barrios Herrera, E.; Muse Sevrini, I.

1995-01-01

On a total of 1152 patients bearing of cancer of she suckles tried in the period 1978-1988, 41 of she(3.5% )corresponding to the variety inflamatory. Her ages was understood between 26 and 73 years , was been 15(63,5% )postmenopause. Clinically they presented commitment mammary exclusive 34,1%, invasion ganglionar lorregional 48,7% and 17% was disseminated remaining. The initial treatment bases on 3-4 cycles of chemotherapy type FCA, safe in patient with more years that they received the association CMF. All then were irradiated with dose of 5000-6000 cGy on she suckles and territories ganglionares. Finish the treatment with 6 to 8 additional cycles of the patients' chemotherapy. Nobody it was subjected to surgical. The middle survive of the population's total it was of 22 meses, has been of 26 for the premenopause and 15 for the posmenopause. The percentage of relapses arrive to 30% and 45% in the located ways they were disseminated during its evolution. It highlights that the therapeutic strategy you bases on the association open chemotherapy, radiotherapy remaining the possibility of the handling of high citostatics dose with or without transplants of osseous medulla osea (Author) [es

Prevalence of Ehrlichia canis, Anaplasma platys, Babesia canis vogeli, Hepatozoon canis, Bartonella vinsonii berkhoffii, and Rickettsia spp. in dogs from Grenada.

Science.gov (United States)

Yabsley, Michael J; McKibben, John; Macpherson, Calum N; Cattan, Peggy F; Cherry, Natalie A; Hegarty, Barbara C; Breitschwerdt, Edward B; O'Connor, Tom; Chandrashekar, Ramaswamy; Paterson, Tara; Perea, Marta Lanza; Ball, Geoffrey; Friesen, Stanley; Goedde, Jill; Henderson, Brooke; Sylvester, Wayne

2008-02-14

To identify the tick-borne pathogens in dogs from Grenada, we conducted a serologic survey for Ehrlichia canis in 2004 (104 dogs) and a comprehensive serologic and molecular survey for a variety of tick-borne pathogens in 2006 (73 dogs). In 2004 and 2006, 44 and 32 dogs (42.3% and 43.8%) were seropositive for E. canis, respectively. In 2006, several tick-borne pathogens were identified by serology and PCR. DNA of E. canis, Anaplasma platys, Babesia canis vogeli, Hepatozoon canis, and Bartonella sp. were identified in 18 (24.7%), 14 (19.2%), 5 (7%), 5 (7%), and 1 (1.4%) dogs, respectively. Six (8.2%) dogs were seropositive for Bartonella vinsonii subsp. berkhoffii. All dogs were seronegative and PCR-negative for Rickettsia spp. Coinfection with two or three pathogens was observed in eight dogs. Partial 16S rRNA E. canis and A. platys sequences were identical to sequences in GenBank. Partial 18S rRNA gene sequences from the Grenadian H. canis were identical to each other and had one possible mismatch (ambiguous base) from H. canis detected from Spain and Brazil. Grenadian B. c. vogeli sequences were identical to B. c. vogeli from Brazil and Japan. All of the detected pathogens are transmitted, or suspected to be transmitted, by Rhipicephalus sanguineus. Results of this study indicate that dogs from Grenada are infected with multiple tick-borne pathogens; therefore, tick-borne diseases should be included as differentials for dogs exhibiting thrombocytopenia, leukopenia, fever, or lethargy. One pathogen, E. canis, is also of potential public health significance.

Vivencias psicosociales reveladas por niños que reciben tratamiento con quimioterapia por cáncer

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BLANCA CECILIA VANEGAS DE AHOGADO

2009-12-01

Full Text Available Se realizó un estudio cualitativo con el propósito de descubrir las vivencias psicosociales de niños y niñas de 9 a 12 años que recibían tratamiento con quimioterapia por cáncer. La recolección de la información se hizo mediante encuentros lúdicos con el apoyo de algunas preguntas básicas que facilitaron las revelaciones narrativas. Tres aspectos se destacan en los hallazgos del estudio: vivencias desfavorables, vivencias relacionadas con la autoestima y vivencias favorables; las dos primeras, de diversa manera, afectan en estos niños su vida personal, familiar, escolar y, en general, todo su entorno. Es de resaltar que, como consecuencia de la caída del cabello, con frecuencia han sido objeto de burla y de rechazo por sus compañeros de estudio, lo que produce el más notorio efecto sobre su autoimagen; por otra parte, el ausentismo escolar conlleva dificultades académicas y sentimientos de tristeza en estos niños, situación que empeora cuando, por motivos de tratamiento, su lugar de residencia está alejado de la ciudad, viéndose sometidos a largos periodos de separación, no solo de su familia sino de sus pares. Se concluye que la mayor parte de las revelaciones son impactantes por su gran contenido de sufrimiento y dolor para estos niños, lo que demuestra la urgencia de retomar los hallazgos del estudio para orientar el cuidado de enfermería de manera más integral y apoyar para que se haga lo propio en el hogar y en las instituciones educativas.

Pedro Teixeira y su viaje por Mesopotamia

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Fuente del Pilar, José Javier

2005-04-01

Full Text Available Pedro Teixeira es un integrante notable de la ilustre nómina de los viajeros portugueses que, a finales del s, XVI y principios del XVII, ensancharon para Occidente las fronteras del mundo. Su conocimiento en España se debe a la publicación en 1994 de su obra «Relaciones del Origen, Descendencia y Sucesión de los Reyes de Persia, y de Harmuz, y de un viaje hecho por el autor dende la India hasta Italia por tierra», en edición realizada por el profesor Eduardo Barajas Sala, lamentablemente fallecido en 1997. En este artículo se ofrece una reseña biográfica de Pedro Teixeira, y un análisis del viaje narrado por el autor en la última parte de sus «Relaciones »: el que desde Ormuz le conducirá, a través de Mesopotamia, hasta la costa del Mediterráneo.…

Violência e mortes por causas externas

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Graciete Oliveira Vieira

2003-02-01

Full Text Available Através de um estudo ecológico caracterizou-se a violência e as mortes por causas externas em Salvador e Bahia utilizando-se dados da Fundação Nacional de Saúde-Ministério da Saúde, dos registros de mortalidade e das estimativas populacionais do IBGE. O risco de morrer por homicídio no Brasil é 3 vezes o do Estados Unidos, chegando a ser 40 vezes superior ao do Japão. Homicídio foi a primeira causa de anos potenciais de vidas perdidos (13,4% no Brasil (1997, seguido por acidentes de trânsito (10,6%. Causas externas foi a segunda causa de morte em Salvador e Bahia (1996. A violência tem raízes sócio-culturais e político-ideológicas e pode ser prevenida por ações intersetoriais e multidisciplinares.

Associação entre violência por parceiro íntimo contra a mulher e infecção por HIV

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Claudia Barros

2011-04-01

Full Text Available OBJETIVO: Analisar a associação entre a violência por parceiro íntimo contra mulheres e a infecção ou suspeita de infecção pelo vírus da imunodeficiência humana (HIV. MÉTODOS: Estudo transversal com base em dados de questionários aplicados face-a-face e de prontuários médicos de 2.780 mulheres de 15 a 49 anos, atendidas em unidades do sistema único de saúde da Grande São Paulo, SP, em 2001-2002. As mulheres foram categorizadas em: usuárias em tratamento por serem "soropositivas para o HIV", com "suspeita de HIV" e aquelas que procuraram os serviços por outros motivos. A violência por parceiro íntimo contra mulheres na vida foi categorizada por gravidade e recorrência dos episódios de violência. A associação com o desfecho foi testada pelo modelo de Poisson com variância robusta e ajustada por variáveis sociodemográficas, sexuais e reprodutivas. RESULTADOS: A prevalência de violência foi de 59,8%. Sofrer violência reiterada e grave apresentou maior associação de infecção confirmada pelo HIV (RP = 1,91. A violência independente da gravidade e da recorrência dos episódios apresentou maior associação para a suspeita de infecção por HIV (RP = 1,29. CONCLUSÕES: A violência por parceiro íntimo contra mulheres tem papel relevante nas situações de suspeita e confirmação da infecção pelo HIV, sendo essencial incluir sua detecção, controle e prevenção como parte da atenção integral à saúde das mulheres.

NCBI nr-aa BLAST: CBRC-TTRU-01-0188 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-TTRU-01-0188 ref|ZP_00142186.1| heme exporter protein B [Rickettsia sibirica 2...46] gb|EAA25595.1| heme exporter protein B [Rickettsia sibirica 246] ZP_00142186.1 0.055 25% ...

NCBI nr-aa BLAST: CBRC-TTRU-01-0560 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-TTRU-01-0560 ref|ZP_00142186.1| heme exporter protein B [Rickettsia sibirica 2...46] gb|EAA25595.1| heme exporter protein B [Rickettsia sibirica 246] ZP_00142186.1 0.14 23% ...

Predominant porB1A and porB1B genotypes and correlation of gene mutations with drug resistance in Neisseria gonorrhoeae isolates in Eastern China

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Tang Renxian

2010-11-01

Full Text Available Abstract Background Variations of porB1A and porB1B genes and their serotypes exist in Neisseria gonorrhoeae isolates from different geographical areas, and some site mutations in the porB1B gene correlate with drug resistance. Methods The β-lactamase production of N. gonorrhoeae isolates was determined by paper acidometric test and nitrocefin discs. The porB1A and porB1B genes of 315 non-penicillinase-producting N. gonorrhoeae (non-PPNG strains were amplified by PCR for sequencing to determine serotypes and site mutations. A duplex PCR was designed to simultaneously detect both porB1A and porB1B genes. Penicillin and tetracycline resistance was assessed by an in vitro drug sensitivity test. Results Of the N. gonorrhoeae isolates, 31.1% tested positive for porB1A and 68.9% for porB1B genes. All the 98 porB1A+ isolates belonging to IA6 serotype with either no mutation at the 120 and 121 sites (88.8% or a D120G (11.2% mutation and were no resistance to both penicillin and tetracycline. Among the 217 porB1B+ isolates, 26.7%, 22.6% and 11.5% belonged to IB3, IB3/6 and IB4 serotypes, respectively. Particularly, two novel chimeric serotypes, IB3/6-IB2 and IB2-IB4-IB2, were found in 77 and 8 porB1B+ isolates. Two hundred and twelve (97.7% of the porB1B+ isolates were presented G120 and/or A121 mutations with 163 (76.9% at both sites. Interestingly, within the 77 porB1B+ isolates belonging to IB3/6-IB2 serotype, 15 were discovered to possess novel deletions at both A121 and N122 sites. All the replacement mutations at these sites in PorB1B were correlated with resistance and the deletion mutation showed the highest resistance. Conclusion N. gonorrhoeae isolates circulating in Eastern China include a sole PorB1A serotype (IA6 and five PorB1B serotypes. Multiple mutations in porB1B genes, including novel A121 and N122 deletions, are correlated with high levels of penicillin and tetracycline resistance.

Conservación por calor

OpenAIRE

Cobos García, Angel; Díaz Rubio, Olga

2011-01-01

Esta unidade didáctica denominada Conservación por calor forma parte da materia «Tecnoloxía do procesado de alimentos» que se impartirá no primeiro semestre do 2º curso do Grao en Nutrición Humana e Dietética. A materia estrutúrase en diferentes unidades didácticas, tratando cada unha delas as diferentes tecnoloxías de procesado dos alimentos, tanto de conservación coma de transformación. A presente unidade didáctica aborda a conservación dos alimentos por calor. Este método permite destruír ...

Las cosas por su nombre

OpenAIRE

Storani, Emilia

2017-01-01

El artículo propone indagar sobre los modos y diferentes formatos que se utilizan tanto en la escritura como en la lectura, para articular con las luchas por la identidad de género. La Ley de Identidad de Género ha sido un puntapié clave para pensarnos a nosotros mismos culturalmente y para pensar a los demás. Pero, ¿cómo mencionamos, escribimos y leemos las diferentes identidades? La escritura, también es un mundo transformador para quienes bregan por una sociedad más libre y sin prejuicios....

Diverticulitis yeyunal perforada por enterolito.

OpenAIRE

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...

Por y para en los manuales de ELE

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Sidoti, Rossana

2008-12-01

Full Text Available La oposición por / para es una de las cuestiones gramaticales que comportan mayor dificultad a la hora de acercarse al estudio del español como L2 sobre todo cuando remiten a conceptos lingüísticos difíciles de entender por no tener ésta referente alguno en el mundo extralingüístico. Si, por un lado, nos resulta fácil entender lo que tiene un referente en el mundo concreto; por otro, no podemos advertir el referente extralingüístico de preposiciones como por / para, si este no existe. Si las preposiciones son elementos abstractos, difíciles de aferrar de por sí, podemos sólo examinar los elementos que éstas ponen en relación y en qué contextos esta relación se determina. Para poder utilizar con precisión las dos preposiciones, es importante no reducirlas a una sola preposición como ocurre en otros idiomas, y sobre todo no relacionarlas sólo a los conceptos de causa y finalidad. Este trabajo se propone individualizar los manuales de español como lengua extranjera más utilizados en las universidades italianas para luego comparar las distintas fuentes de información sobre por / para y exponer comentarios, reflexiones y sugerencias sobre el tema con el fin de precisar en qué medida se puede mejorar lo que los manuales reducen o generalizan, puesto que para los estudiantes de ELE estos representan una herramienta valiosa a la que acudir.

Assessment of Domestic Goats as Models for Experimental and Natural Infection with the North American Isolate of Rickettsia slovaca.

Science.gov (United States)

Lukovsky-Akhsanov, Nicole; Keating, M Kelly; Spivey, Pamela; Lathrop, George W; Powell, Nathaniel; Levin, Michael L

2016-01-01

Rickettsia slovaca is a tick-borne human pathogen that is associated with scalp eschars and neck lymphadenopathy known as tick-borne lymphadenopathy (TIBOLA) or Dermacentor-borne necrosis erythema and lymphadenopathy (DEBONEL). Originally, R. slovaca was described in Eastern Europe, but since recognition of its pathogenicity, human cases have been reported throughout Europe. European vertebrate reservoirs of R. slovaca remain unknown, but feral swine and domestic goats have been found infected or seropositive for this pathogen. Recently, a rickettsial pathogen identical to R. slovaca was identified in, and isolated from, the American dog tick, Dermacentor variabilis. In previous experimental studies, this organism was found infectious to guinea pigs and transovarially transmissible in ticks. In this study, domestic goats (Capra hircus) were experimentally inoculated with the North American isolate of this R. slovaca-like agent to assess their reservoir competence-the ability to acquire the pathogens and maintain transmission between infected and uninfected ticks. Goats were susceptible to infection as demonstrated by detection of the pathogen in skin biopsies and multiple internal tissues, but the only clinical sign of illness was transient fever noted in three out of four goats, and reactive lymphoid hyperplasia. On average, less than 5% of uninfected ticks acquired the pathogen while feeding upon infected goats. Although domestic goats are susceptible to the newly described North American isolate of R. slovaca, they are likely to play a minor role in the natural transmission cycle of this pathogen. Our results suggest that goats do not propagate the North American isolate of R. slovaca in peridomestic environments and clinical diagnosis of infection could be difficult due to the brevity and mildness of clinical signs. Further research is needed to elucidate the natural transmission cycle of R. slovaca both in Europe and North America, as well as to identify a

Análisis de la recurrencia de cáncer de lengua considerando la presencia de eventos competitivos.

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Raúl Vicente Mantilla Quispe

2008-10-01

Full Text Available Objetivo: Estimar la probabilidad de recurrencia en pacientes con cáncer de lengua según la edad, el estado ganglionar patológico y el tipo de tratamiento de los pacientes considerando la muerte antes de la recurrencia como evento competitivo. Material y métodos: Serie de casos retrospectiva de 290 pacientes con cáncer de lengua, con tratamiento en el INEN, entre los años 1977 y 2000. Se excluyeron del estudio 29 pacientes tratados solo con radioterapia. De los 261 pacientes, 31 solo tuvieron tratamiento del tumor primario. Resultados: La recurrencia fue 36,8%, la recurrencia local fue la más frecuente. La incidencia acumulada de la recurrencia a los 5 años, con el método de Kaplan Meier, se estimó en 44,7%, y según el análisis de riesgos competitivos en 42,4%. En el análisis univariado considerando riesgos competitivos, las incidencias acumuladas fueron: 56,8 y 38,9% en pacientes menores o iguales que 45 y mayores que 45 años respectivamente (p = 0,1556, 29,4% y 50,5% en pacientes con ganglios patológicos negativos y positivos, respectivamente (p = 0,0002, y 37,5% en pacientes con cirugía, y 47,4% con radioterapia (p = 0,03. En el análisis multivariado, con regresión de riesgos competitivos, no se encontró diferencia entre los tipos de tratamiento sobre la recurrencia (RR = 1,146, p = 0,620. Conclusiones: La pequeña diferencia entre los resultados del método Kaplan Meier y el que toma en cuenta eventos competitivos se debe a la baja tasa del evento competitivo, más aún por que se trata de muerte no relacionada con la enfermedad. La tasa de recurrencia fue similar al reportado en la literatura. Sólo se encontró diferencia significativa en la tasa de recurrencia en el grupo con compromiso ganglionar positivo. Aunque la comparación con los métodos estándar, Kaplan Meier y Regresión de Cox, muestra resultados similares se deben tener en cuenta los eventos competitivos. (Rev Med Hered 2008;19: 145-151.

NCBI nr-aa BLAST: CBRC-SARA-01-0522 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-SARA-01-0522 ref|YP_001499570.1| Peptidyl-tRNA hydrolase [Rickettsia massiliae... MTU5] gb|ABV85023.1| Peptidyl-tRNA hydrolase [Rickettsia massiliae MTU5] YP_001499570.1 4.7 36% ...

NCBI nr-aa BLAST: CBRC-TTRU-01-0560 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-TTRU-01-0560 ref|YP_001499163.1| Heme exporter protein B [Rickettsia massiliae... MTU5] gb|ABV84616.1| Heme exporter protein B [Rickettsia massiliae MTU5] YP_001499163.1 0.18 23% ...

NCBI nr-aa BLAST: CBRC-TTRU-01-0188 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-TTRU-01-0188 ref|YP_001499163.1| Heme exporter protein B [Rickettsia massiliae... MTU5] gb|ABV84616.1| Heme exporter protein B [Rickettsia massiliae MTU5] YP_001499163.1 0.055 25% ...

NCBI nr-aa BLAST: CBRC-TTRU-01-0188 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-TTRU-01-0188 ref|YP_002845019.1| Heme exporter protein B [Rickettsia africae E...SF-5] gb|ACP53276.1| Heme exporter protein B [Rickettsia africae ESF-5] YP_002845019.1 0.055 25% ...

NCBI nr-aa BLAST: CBRC-TTRU-01-0560 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-TTRU-01-0560 ref|YP_002845019.1| Heme exporter protein B [Rickettsia africae E...SF-5] gb|ACP53276.1| Heme exporter protein B [Rickettsia africae ESF-5] YP_002845019.1 0.14 23% ...

NCBI nr-aa BLAST: CBRC-VPAC-01-1556 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-VPAC-01-1556 ref|YP_002845019.1| Heme exporter protein B [Rickettsia africae E...SF-5] gb|ACP53276.1| Heme exporter protein B [Rickettsia africae ESF-5] YP_002845019.1 0.27 29% ...

Factors affecting population dynamics of maternally transmitted endosymbionts in Bemisia tabaci.

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Huipeng Pan

Full Text Available While every individual of Bemisia tabaci (Hemiptera: Aleyrodidae harbors the primary symbiont (P-symbiont Portiera, the infection frequencies of the six secondary symbionts (S-symbionts including Hamiltonella, Arsenophonus, Cardinium, Wolbachia, Rickettsia and Fritschea vary greatly among different populations. To characterize the factors influencing the infection dynamics of the six S-symbionts in B. tabaci, gene-specific PCR were conducted to screen for the presence of the P-symbiont Portiera and the six S-symbionts in 61 (17 B and 44 Q biotypes field populations collected from different plant species and locations in China. All individuals of the 61 populations hosted the P-symbiont Portiera, but none of them harbored Arsenophonus and Fritschea. The presence and infection rates of Hamiltonella, Cardinium, Rickettsia, Wolbachia and their co-infections Rickettsia + Hamiltonella (RH, Rickettsia + Cardinium (RC, Hamiltonella + Cardinium (HC and Rickettsia + Hamiltonella + Cardinium (RHC varied significantly among the 61 field populations; and the observed variations can be explained by biotypes, sexes, host plants and geographical locations of these field populations. Taken together, at least three factors including biotype, host plant and geographical location affect the infection dynamics of S-symbionts in B. tabaci.

Wolbachia: Evolutionary novelty in a rickettsial bacteria

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Anderson Cort L

2001-11-01

Full Text Available Abstract Background Although closely related, the alpha-proteobacteria Wolbachia and the Rickettsiacae (Rickettsia and Ehrlichia, employ different evolutionary life history strategies. Wolbachia are obligate endocellular symbionts that infect an extraordinary host range and, in contrast to the infectious and pathogenic Rickettsia and Ehrlichia, profoundly influence host reproductive biology. Results Phylogenies of the Rickettsia, Ehrlichia, and Wolbachia were independently inferred from 16S rDNA sequences and GroEL amino acid sequences. Topologies inferred from both sets of sequence data were consistent with one another, and both indicate the genus Wolbachia shared a common ancestor most recently with Ehrlichia. These two genera are a sister group to the genus Rickettsia. Mapping biological properties onto this phylogeny reveals that manipulation of host reproduction, characteristic of Wolbachia strains, is a derived characteristic. This evolutionary novelty is accompanied by the loss of the ability to infect vertebrate hosts. Conclusions Because of the contrasting transmission strategies employed by each, Wolbachia is expected to maximize efficiency of vertical transmission, while Ehrlichia and Rickettsia will optimize horizontal transfer of infection. Wolbachia manipulation of host reproduction could thus be viewed as strategy employed by this bacterium to foster its own propagation via vertical transmission.

Rickettsiosis, una enfermedad letal emergente y re-emergente en Colombia

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Juan David Rodas González

2012-04-01

Full Text Available Rickettsiosis: a deadly emerging and re-emerging disease in Colombia. Rickettsiosis was first described in Colombia in 1937 byDr Luis Patiño during an outbreak of a disease with unspecific signs. Rickettsia is a genus of Gram-negative intracellular obligatorybacteria having caused several epidemics around the world, and are transmitted mainly by ticks, fleas, lice and mites. The most fatalwithin this group of diseases is known as Rocky Mountain Spotted Fever (RMSF, which is caused by Rickettsia rickettsia. There is alsothe endemic typhus caused by Rickettsia typhi and epidemic typhus caused by Rickettsia prowazekii. In Colombia, several outbreaks ofRMSF have occurred during the last decade. The best known among those have hit the municipalities of Necoclí and Turbo, in Antioquiain 2006 and 2008 respectively, and Los Cordobas in the department of Cordoba in 2007. The goal of this review is to describe the state ofthe art of rickettsiosis, a forgotten lethal disease that has re-emerged in our country, and leave some questions as an inspiration for future research that will hopefully lead scientists to a better understanding of this entity potentially endemic in some areas of Colombia.

Rickettsial Disease in the Peruvian Amazon Basin.

Science.gov (United States)

Kocher, Claudine; Morrison, Amy C; Leguia, Mariana; Loyola, Steev; Castillo, Roger M; Galvez, Hugo A; Astete, Helvio; Flores-Mendoza, Carmen; Ampuero, Julia S; Bausch, Daniel G; Halsey, Eric S; Cespedes, Manuel; Zevallos, Karine; Jiang, Ju; Richards, Allen L

2016-07-01

Using a large, passive, clinic-based surveillance program in Iquitos, Peru, we characterized the prevalence of rickettsial infections among undifferentiated febrile cases and obtained evidence of pathogen transmission in potential domestic reservoir contacts and their ectoparasites. Blood specimens from humans and animals were assayed for spotted fever group rickettsiae (SFGR) and typhus group rickettsiae (TGR) by ELISA and/or PCR; ectoparasites were screened by PCR. Logistic regression was used to determine associations between patient history, demographic characteristics of participants and symptoms, clinical findings and outcome of rickettsial infection. Of the 2,054 enrolled participants, almost 2% showed evidence of seroconversion or a 4-fold rise in antibody titers specific for rickettsiae between acute and convalescent blood samples. Of 190 fleas (Ctenocephalides felis) and 60 ticks (Rhipicephalus sanguineus) tested, 185 (97.4%) and 3 (5%), respectively, were positive for Rickettsia spp. Candidatus Rickettsia asemboensis was identified in 100% and 33% of the fleas and ticks tested, respectively. Collectively, our serologic data indicates that human pathogenic SFGR are present in the Peruvian Amazon and pose a significant risk of infection to individuals exposed to wild, domestic and peri-domestic animals and their ectoparasites.

Pronóstico de la diarrea por rotavirus

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Mota-Hernández Felipe

2001-01-01

Full Text Available Objetivo. Comparar la gravedad de la diarrea por rotavirus (RV y por no rotavirus. Material y métodos. Estudio transversal en 520 lactantes con diarrea aguda, efectuado entre octubre de 1994 y marzo de 1995 en siete centros del primer nivel de atención en cinco estados de México. El diagnóstico de RV se realizó con ensayo inmunoenzimático o por electroforesis. El análisis se hizo a través de medidas de tendencia central. Los resultados se presentan como promedio y desviación estándar o mediana o variación. Resultados. Se aisló RV en 264 lactantes (50.7% con predominio en varones de 6 meses a un año. Las manifestaciones clínicas fueron significativamente diferentes entre el grupo rotavirus positivo y el grupo rotavirus negativo en mediana de evacuaciones por 24 horas, frecuencia de vómitos, temperatura > 38° C, deshidratación y calificación de gravedad, respectivamente. Conclusiones. Estos resultados mostraron peor pronóstico por mayor gravedad de la diarrea por RV en lactantes, con relación a otra etiología. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.html

Miasis cutanea por cordylobia anthropophaga

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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.

Associação entre violência por parceiro íntimo contra a mulher e infecção por HIV Asociación entre violencia contra la mujer por pareja íntima e infección por VIH Association between intimate partner violence against women and HIV infection

Directory of Open Access Journals (Sweden)

Claudia Barros

2011-04-01

Full Text Available OBJETIVO: Analisar a associação entre a violência por parceiro íntimo contra mulheres e a infecção ou suspeita de infecção pelo vírus da imunodeficiência humana (HIV. MÉTODOS: Estudo transversal com base em dados de questionários aplicados face-a-face e de prontuários médicos de 2.780 mulheres de 15 a 49 anos, atendidas em unidades do sistema único de saúde da Grande São Paulo, SP, em 2001-2002. As mulheres foram categorizadas em: usuárias em tratamento por serem "soropositivas para o HIV", com "suspeita de HIV" e aquelas que procuraram os serviços por outros motivos. A violência por parceiro íntimo contra mulheres na vida foi categorizada por gravidade e recorrência dos episódios de violência. A associação com o desfecho foi testada pelo modelo de Poisson com variância robusta e ajustada por variáveis sociodemográficas, sexuais e reprodutivas. RESULTADOS: A prevalência de violência foi de 59,8%. Sofrer violência reiterada e grave apresentou maior associação de infecção confirmada pelo HIV (RP = 1,91. A violência independente da gravidade e da recorrência dos episódios apresentou maior associação para a suspeita de infecção por HIV (RP = 1,29. CONCLUSÕES: A violência por parceiro íntimo contra mulheres tem papel relevante nas situações de suspeita e confirmação da infecção pelo HIV, sendo essencial incluir sua detecção, controle e prevenção como parte da atenção integral à saúde das mulheres.OBJETIVO: Analizar la asociación entre la violencia contra mujeres por pareja íntima y la infección o sospecha de infección por el virus de inmunodeficiencia humana (VIH. MÉTODOS: Estudio transversal con base en datos de cuestionarios aplicados cara-a cara y de prontuarios médicos de 2.780 mujeres de 15 a 49 años, atendidas en unidades del sistema único de salud de la Gran Sao Paulo, Sureste de Brasil, en 2001-2002. Las mujeres fueron categorizadas en: usuarias en tratamiento por ser

Itinerarios Didácticos por la isla de Lanzarote

OpenAIRE

Becerra-Ramírez, Rafael; González Cárdenas, Elena; Gosálvez, Rafael U.; Escobar Lahoz, Estela; Dóniz-Páez, Javier

2013-01-01

Con la confección de esta guía de itinerarios didácticos por la isla de Lanzarote pretendemos contribuir a un mayor conocimiento de las características geográficas de este espacio dominado por las formas volcánicas que caracterizan un paisaje modificado por la mano del hombre que convive con los volcanes y los usa, tradicionalmente como soporte de sus cultivos, y modernamente como base de la industria turística. Los itinerarios didácticos por la isla de Lanzarote son la adaptación de los t...

Signos Vitales de los CDC-Muertes por intoxicación por alcohol (Alcohol Poisoning Deaths)

Centers for Disease Control (CDC) Podcasts

2015-01-06

Este podcast se basa en la edición de enero del 2015 del informe Signos Vitales de los CDC. En los Estados Unidos, mueren en promedio seis personas cada día debido a la intoxicación por alcohol. Infórmese sobre lo que puede hacer para prevenir los atracones de alcohol y las intoxicaciones por alcohol.  Created: 1/6/2015 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 1/6/2015.

NCBI nr-aa BLAST: CBRC-ACAR-01-0595 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-ACAR-01-0595 ref|YP_246431.1| Zinc/manganese ABC transporter permease protein ...[Rickettsia felis URRWXCal2] gb|AAY61266.1| Zinc/manganese ABC transporter permease protein [Rickettsia felis URRWXCal2] YP_246431.1 2.0 21% ...