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1.
Rev. bras. parasitol. vet ; 29(3): e005320, 2020. tab, graf
Article in English | LILACS | ID: biblio-1138121

ABSTRACT

Abstract Tick-borne rickettsial pathogens (TBRP) are important causes of infections in both dogs and humans. Dogs play an important role as a biological host for several tick species and can serve as sentinels for rickettsial infections. Our aim was to determine the presence of TBRP in dogs and in dog-associated ticks and their potential risk to human diseases in Medellin, Colombia. DNA for E. canis (16S rRNA and dsb) and A. platys (groEl) was detected in 17.6% (53/300) and 2.6% (8/300) of dogs, respectively. Antibodies against Ehrlichia spp. 82 (27.3%) and Anaplasma spp. 8 (2.6%) were detected in dogs. Antibody reactivity against both agents were found in 16 dogs (5.3%). Eight dogs showed antibody for Rickettsia spp. with titers that suggest 3 of them had a probable exposure to R. parkeri. Rhipicephalus sanguineus s.l. (178/193) was the main tick in dogs, followed by R. microplus (15/193). The minimum infection rates (MIR) in R. sanguineus were 11.8% for E. canis and 3.4% for A. platys. E. canis and A. platys are the main TBRP infecting dogs and ticks and R. sanguineus s.l. is likely involved in the transmission of both agents. Interestingly, we found serological evidence of exposure in dogs for spotted fever group rickettsiae.


Resumo As riquétsias transmitidas por carrapatos (RTC) são causas importantes de infecção em cães e humanos. Os cães exercem um papel essencial como hospedeiros biológicos para diversas espécies de carrapatos, assim como podem ser úteis como sentinelas de infecções por riquétsias. O intuito deste estudo foi determinar a presença de RTC em cães, assim como em seus carrapatos, para determinar o risco potencial de doença humana em Medellín, Colômbia. DNA de Ehrlichia canis (16S rRNA e dsb) e Anaplasma platys (groEl) foi detectado em 17,6% (53/300) e 2,6% (8/300) dos cães, respectivamente. Anticorpos contra Ehrlichia spp. (82; 27,3%) e Anaplasma spp. (8; 2,6%) foram detectados nos cães. Reatividade de anticorpos contra ambos patógenos (Ehrlichia e Anaplasma) foi detectada em 16 cães (5,3%). Oito animais apresentaram anticorpos contra Rickettsia spp., e 3 deles sugerem uma provável exposição a Rickettsia parkeri. Rhipicephalus sanguineus s.l. (178/193) foi a principal espécie de carrapatos, seguida de R. microplus (15/193). A taxa de infecção mínima em R. sanguineus foi 11,8% para E. canis e 3,4% para A. platys. E. canis e A. platys são as principais RTC que infectam cãese R. sanguineus s.l. provavelmente está envolvido na transmissão de ambos os agentes. É evidente, porém, a exposição sorológica dos cães a riquétsias do grupo da febre maculosa.


Subject(s)
Humans , Animals , Dogs , Ehrlichiosis/microbiology , Ehrlichiosis/epidemiology , Dog Diseases/microbiology , Dog Diseases/parasitology , Anaplasmosis/microbiology , Anaplasmosis/epidemiology , Rickettsia/genetics , Rickettsia Infections/microbiology , Rickettsia Infections/veterinary , Rickettsia Infections/epidemiology , RNA, Ribosomal, 16S , Ehrlichiosis/veterinary , Tick-Borne Diseases/microbiology , Tick-Borne Diseases/veterinary , Tick-Borne Diseases/epidemiology , Colombia/epidemiology , Rhipicephalus sanguineus/microbiology , Ehrlichia/genetics , Anaplasma/genetics , Antibodies, Bacterial/blood
2.
Rev. bras. parasitol. vet ; 29(3): e010020, 2020. graf
Article in English | LILACS | ID: biblio-1138105

ABSTRACT

Abstract A histopathological survey was conducted to investigate the presence of microparasites in fish Archosargus probatocephalus in a river near Maceió, Brazil. Light microscope observations of fragments of gill showed the presence of small cysts containing numerous myxospores that were morphologically identified as Henneguya. Transmission electron microscopy observations further revealed several gill cells containing groups of prokaryotic cells within large cytoplasmic vacuoles. Each infected host cell displayed a single vacuole containing a variable number of Rickettsia-like cells (up to 11), some of which presented the dumbbell shape characteristic of binary fission. The Rickettsia-like cells were pleomorphic, without a nucleus and with chromatin dispersed in the cytoplasm. They had a thin electron-dense wall of Gram-negative type. The morphology of these prokaryotic was similar to those of the order Rickettsiales and was described as a Rickettsia-like organism. Histopathological evaluation showed that several vacuole membranes had a lysed appearance. Some had ruptured, thus allowing direct contact between the Rickettsia-like organism and the cytoplasm of the host cell. The rupturing of the branchial epithelium may have contributed towards reduction of the surface area of the gills, but it is not possible to say that this was the cause of the host's death.


Resumo Um levantamento histopatológico foi realizado para pesquisar a presença de microparasitas, no peixe Archosargus probatocephalus, em um rio próximo a Maceió, Brasil. Observações ao microscópio óptico de fragmentos de brânquias mostraram a presença de pequenos cistos contendo numerosos mixósporos, identificados morfologicamente como Henneguya. Ocasionalmente, na microscopia eletrônica de transmissão, foram observados vários corpos citoplasmáticos de inclusão, grupo aparentemente de células procarióticas que vivem dentro de um grande vacúolo citoplasmático de algumas células branquiais. As células hospedeiras infectadas tinham um único vacúolo contendo um número variável de células do tipo Rickettsia, até 11, algumas das quais em forma do haltere, característica da fissão binária. Essas células eram pleomórficas sem núcleo, tendo a cromatina dispersa no citoplasma e possuíam uma parede densa de elétrons finos do tipo Gram-negativo. A morfologia dessas células procarióticas foi semelhante àquelas da ordem Rickettsiales e foram descritas como organismos tipo Rickettsiae. A histopatologia mostra várias membranas de vacúolos circundantes com aspetos lisados, enquanto outras apresentam rupturas que mostram contato direto do organismos tipo Rickettsiae com o citoplasma da célula hospedeira. A ruptura do epitélio branquial pode ter contribuído para a redução da superfície das brânquias, mas não é possível afirmar que foi a causa da morte do hospedeiro.


Subject(s)
Animals , Rickettsia Infections/microbiology , Perciformes/microbiology , Fish Diseases/microbiology , Fish Diseases/pathology , Gills/microbiology , Gills/ultrastructure , Rickettsia/ultrastructure , Rickettsia Infections/pathology , Rickettsia Infections/veterinary , Brazil
3.
Rev. bras. parasitol. vet ; 28(4): 713-721, Oct.-Dec. 2019. tab, graf
Article in English | LILACS | ID: biblio-1058000

ABSTRACT

Abstract Rickettsia spp. bacteria are responsible for tick-borne diseases worldwide, mostly maintained by rickettsial amplifiers capybaras in Brazilian endemic areas. The campus of the University of São Paulo, in southeastern Brazil, is an area endemic for Brazilian spotted fever (BSF), with high density of capybaras and Amblyomma spp., along with confirmed human cases. Besides capybaras, the university has also an in-campus high population of sheltered and free-roaming cats. Accordingly, the aim of this study was to determine the prevalence and characteristics associated with Rickettsia rickettsii, Rickettsia parkeri and Rickettsia felis exposure among cats in a BSF-endemic area. Out of 51 cats sampled, 23/35 shelter (65.7%) and 5/16 free-roaming (31.2%) were positive (titers ≥ 64) for at least one Rickettsia species. Ticks species were present in 3/16 free-roaming cats (18.8%), consisting of Amblyomma spp., nymphs of Amblyomma sculptum and adult Rhipicephalus sanguineus sensu lato. Despite sharing the capybaras environment, the seropositivity among the free-roaming and shelter cats was lower than owned cats in other endemic areas. Whether equally or less exposed to rickettsial infection, compared with owned cats in endemic areas, free-roaming and shelter cats may be used as environmental sentinels for human exposure to rickettsiae in such areas.


Resumo Espécies de Rickettsia têm sido responsáveis por doenças transmitidas por carrapatos no mundo, a maioria mantida por hospedeiros amplificadores, como as capivaras em áreas endêmicas no Brasil. A Universidade de São Paulo, em Piracicaba, no sudeste do Brasil, é uma área endêmica para a Febre Maculosa Brasileira (FMB), com alta densidade de capivaras e Amblyomma spp., e com casos humanos confirmados. Além de capivaras, a universidade também possui gatos em um abrigo e de vida livre. Assim, o objetivo deste estudo foi determinar a prevalência e as características associadas com exposição à Rickettsia rickettsii, Rickettsia parkeri e Rickettsia felis em gatos de área endêmica para a FMB. Dos 51 gatos amostrados, 23/35 (65,7%) do abrigo e 5/16 (31,2%) de vida livre foram positivos (títulos ≥ 64) para pelo menos uma Rickettsia spp. Carrapatos estiveram presentes em 3/16 (18,8%) gatos de vida livre, representados por Amblyomma spp., ninfas de Amblyomma sculptum e adultos de Rhipicephalus sanguineus sensu lato. Apesar de compartilharem o ambiente com capivaras, os gatos amostrados foram igualmente ou menos expostos à infecção riquetsial do que os gatos com proprietário em outras áreas endêmicas, podendo ser usados como sentinelas para exposição humana à riquétsias nessas áreas.


Subject(s)
Animals , Male , Female , Cats , Rickettsia/isolation & purification , Rickettsia Infections/veterinary , Ticks/microbiology , Cat Diseases/microbiology , Rickettsia/classification , Rickettsia Infections/diagnosis , Rickettsia Infections/microbiology , Rickettsia Infections/epidemiology , Brazil , Rocky Mountain Spotted Fever/transmission , Cat Diseases/diagnosis , Cat Diseases/epidemiology
4.
Rev. peru. med. exp. salud publica ; 35(4): 630-635, oct.-dic. 2018. tab
Article in Spanish | LILACS | ID: biblio-985789

ABSTRACT

RESUMEN Con el objetivo de caracterizar molecularmente aislamientos rickettsiales procedentes de humanos con síndrome febril agudo inespecífico se realizó un estudio descriptivo transversal, con aislamientos propagados en cultivos celulares Vero ATCC y líneas alternativas, verificando viabilidad mediante Inmunofluoresencia Indirecta (IFI). Previa extracción del ADN, se amplificó el gen gltA mediante PCR convencional, y se analizó su secuencia. Doce aislamientos fueron amplificados, cinco con suficiente ADN para secuenciarlos, evidenciando compatibilidad con R. asembonensis en cuatro, y estrecha identidad con Coxiella burnetti en uno. Al menos tres de siete líneas celulares alternativas mostraron rendimiento significativo en sub cultivos. Se identificó R. asembonensis en cuatro aislamientos de humanos con síndrome febril agudo inespecífico, procedentes de las regiones de Ayacucho, Cajamarca y Madre de Dios en Perú, y Coxiella burnetti en uno procedente de la región Loreto.


ABSTRACT With the objective of molecularly characterizing rickettsial isolates from humans with non-specific acute febrile syndrome, a cross-sectional descriptive study was conducted, with isolates propagated in Vero ATCC cellular cultures and alternative lines, verifying the viability by means of Indirect Immunofluorescence. Prior to DNA extraction, the gltA gene was amplified by means of conventional PCR, and its sequence was analyzed. Twelve isolates were amplified, five with sufficient DNA so as to sequence them, exhibiting compatibility with R. asembonensis in four, and a close identity with Coxiella burnetti in one. At least three of seven alternative cellular lines showed significant yield in sub-cultures. R. asembonensis was identified in four isolates of humans with non-specific acute febrile syndrome, coming from the regions of Ayacucho, Cajamarca, and Madre de Dios in Peru, and Coxiella burnetti in one coming from the Loreto region.


Subject(s)
Humans , Rickettsia/isolation & purification , Rickettsia/genetics , Rickettsia Infections/microbiology , DNA, Bacterial/analysis , Fever/microbiology , Peru , Syndrome , Acute Disease , Cross-Sectional Studies
5.
Braz. j. microbiol ; 46(3): 879-883, July-Sept. 2015. tab
Article in English | LILACS | ID: lil-755800

ABSTRACT

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 auriculariumcollected 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.

.


Subject(s)
Animals , Ixodidae/microbiology , Rickettsia Infections/microbiology , Rickettsia/genetics , Rickettsia/isolation & purification , Tick Infestations/microbiology , Animals, Wild , Armadillos , Base Sequence , Birds , Brazil , Bacterial Outer Membrane Proteins/genetics , Bacterial Proteins/genetics , Citrate (si)-Synthase/genetics , DNA, Bacterial , Heat-Shock Proteins/genetics , Mephitidae , Molecular Sequence Data , Molecular Typing , Porcupines , Periplasmic Proteins/genetics , Sequence Analysis, DNA , Serine Endopeptidases/genetics
6.
Rev. chil. infectol ; 31(5): 569-576, oct. 2014. ilus, tab
Article in Spanish | LILACS | ID: lil-730274

ABSTRACT

Tick-borne rickettsial diseases are potentially life threatening infections that in Latin America have an emerging and reemerging character. Until few years ago, Rickettsia rickettsia was the only tick-borne rickettsia present in America; but nowadays several other species such as R. parkeri and R. massiliae are causing disease in humans in the region. In addition, new species are being described; although their pathogenicity has not been confirmed they should be considered as potential pathogens. Since the microbiological diagnosis of rickettsioses can take days or weeks, a high clinical suspicion and early start of appropriate treatment are crucial. In this review the distribution and main clinical manifestations of tick-borne rickettsial diseases in Latin America are detailed. Since R. felis has been found in ticks and the role of this vector has not been clarified, we have included a section about this pathogen.


Las rickettsiosis transmitidas por garrapatas son infecciones potencialmente letales, que en Latinoamérica tienen carácter emergente y re-emergente. Hasta hace escasos años, la única rickettsiosis transmitida por garrapatas era causada por Rickettsia rickettsii, pero en la actualidad existen otras especies como R. parkeri y R. massiliae que están provocando enfermedad en humanos en la región. Por otro lado, se están describiendo candidatos a nuevas especies de Rickettsia, que aunque no han probado su patogenicidad deben considerarse como potencialmente patógenos. Dado que el diagnóstico microbiológico puede tardar días o semanas, resulta fundamental una alta sospecha clínica y la instauración precoz de un tratamiento adecuado. En esta revisión se detalla la distribución y principales manifestaciones clínicas de las rickettsiosis transmitidas por garrapatas en Latinoamérica. Se ha incluido una sección sobre la infección por R. felis, por haberse encontrado esta especie en garrapatas, y no haberse aclarado el papel de este vector en su ciclo epidemiológico.


Subject(s)
Animals , Humans , Rickettsia Infections/classification , Rickettsia/classification , Tick-Borne Diseases/classification , Ticks/microbiology , Latin America , Rickettsia Infections/microbiology , Rickettsia/isolation & purification , Tick-Borne Diseases/microbiology
7.
Rev. chil. infectol ; 31(1): 54-65, feb. 2014. ilus, tab
Article in Spanish | LILACS | ID: lil-706547

ABSTRACT

Tick-borne rickettsioses are worldwide infectious diseases that are considered emerging and re-emerging. Until recently the only tick-borne rickettsiosis present in Latin America was Rickettsia rickettsii infection, but to date, with the incorporation of new tools as PCR and sequencing and the quick cellular close tube cultures (Shell-vial), new species has been involved as human pathogens. In these guidelines, we offer an update of the microbiological assays for diagnosing rickettsioses. Besides we have included a section in which the most important hard ticks involved in human rickettsioses in Latinoamerica are detailed.


Las rickettsiosis transmitidas por garrapatas son afecciones de distribución mundial, que por diferentes motivos se pueden considerar emergentes y reemergentes. Hasta hace escasos años la única rickettsiosis transmitida por garrapatas en Latinoamérica era la infección por Rickettsia rickettsii, pero en la actualidad y fundamentalmente, gracias a la incorporación de nuevas herramientas para el diagnóstico microbiológico como la reacción en cadena de la polimerasa y secuenciación o el cultivo celular rápido en tubo cerrado, se han descrito e involucrado otras especies de Rickettsia en la producción de patología humana. En estas guías se detallan y describen las diferentes técnicas utilizadas para el diagnóstico microbiológico de las rickettsiosis. Además, se incluye una sección en la que se detallan las especies más importantes de garrapatas duras relacionadas con las rickettsiosis en Latinoamérica, con claves para su clasificación taxonómica.


Subject(s)
Animals , Humans , Arachnid Vectors/microbiology , Rickettsia Infections/diagnosis , Rickettsia/classification , Tick-Borne Diseases/diagnosis , Ticks/microbiology , Cell Culture Techniques , Fluorescent Antibody Technique, Indirect , Latin America , Polymerase Chain Reaction , Rickettsia Infections/microbiology , Rickettsia Infections/transmission , Rickettsia/isolation & purification , Rocky Mountain Spotted Fever/diagnosis , Rocky Mountain Spotted Fever/microbiology , Tick-Borne Diseases/microbiology , Ticks/anatomy & histology , Ticks/classification
8.
Rev. Soc. Bras. Med. Trop ; 44(3): 395-396, May-June 2011.
Article in English | LILACS | ID: lil-593371

ABSTRACT

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


Febre maculosa brasileira (FMB) é a mais importante e frequente doença rickettsial no Brasil. Relatamos um caso fatal de FMB em um homem negro de 32 anos de idade que morreu de choque irreversível após cinco dias de febre, cefaléia intensa, dor abdominal, e sem evidência de exantema. Amostras de baço, rim e coração coletadas na necropsia foram positivas para Rickettsia rickettsii por PCR e sequenciamento. Os autores ressaltam a necessidade de um alto índice de suspeita diagnóstica para febre maculosa em pacientes negros. Ausência de exantema não deve dissuadir os clínicos de considerar a possibilidade de FMB e iniciar a terapêutica empírica.


Subject(s)
Adult , Humans , Male , Rickettsia rickettsii , Rickettsia Infections/diagnosis , Shock, Septic/microbiology , Blacks , Fatal Outcome , Rickettsia Infections/microbiology , Rickettsia rickettsii/genetics , Rickettsia rickettsii/immunology
9.
Rev. Inst. Med. Trop. Säo Paulo ; 51(6): 337-339, Oct.-Dec. 2009. ilus
Article in English | LILACS | ID: lil-539453

ABSTRACT

We report three new rickettsiosis human cases in Uruguay. The three clinical cases presented clinical manifestations similar to previous reported cases of Rickettsia parkeri in the United States; that is mild fever (< 40 ºC), malaise, headache, rash, inoculation eschar at the tick bite site, regional lymphadenopathy, and no lethality. Serological antibody-absorption tests with purified antigens of R. parkeri and Rickettsia rickettsii, associated with immunofluorescence assay indicated that the patients in two cases were infected by R. parkeri. Epidemiological and clinical evidences, coupled with our serological analysis, suggest that R. parkeri is the etiological agent of human cases of spotted fever in Uruguay, a disease that has been recognized in that country as cutaneous-ganglionar rickettsiosis.


São relatados três novos casos humanos de rickettsiose no Uruguai. Os três casos clínicos apresentam manifestações clínicas semelhantes às descritas em casos de infecção por Rickettsia parkeri previamente relatados nos Estados Unidos, tais como: febre moderada (< 40 ºC), mal-estar, cefaléia, exantema, escara de inoculação no sítio de fixação do carrapato, linfadenopatia regional e ausência de letalidade. Testes sorológicos de absorção de anticorpos com antígenos de R. parkeri e Rickettsia rickettsii, associados à reação de imunofluorescência indireta, sugerem que os pacientes de dois casos foram infectados por R. parkeri. Evidências clínicas e epidemiológicas, associadas com nossas análises sorológicas, sugerem que R. parkeri é o agente etiológico de casos humanos de febre maculosa no Uruguai, uma doença que tem sido reconhecida naquele país como rickettsiose cutâneo-ganglionar.


Subject(s)
Adult , Child , Humans , Male , Middle Aged , Antibodies, Bacterial/blood , Rickettsia Infections/microbiology , Rickettsia/immunology , Fluorescent Antibody Technique, Indirect , Rickettsia Infections/diagnosis , Rickettsia/classification , Uruguay
10.
Mem. Inst. Oswaldo Cruz ; 103(2): 191-194, Mar. 2008. ilus, tab
Article in English | LILACS | ID: lil-480633

ABSTRACT

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


Subject(s)
Animals , Dogs , Humans , Animals, Domestic/parasitology , DNA, Bacterial/genetics , Siphonaptera/microbiology , Insect Vectors/microbiology , Rickettsia felis/genetics , Ticks/microbiology , Brazil/epidemiology , DNA, Bacterial/isolation & purification , Endemic Diseases , Environment , Siphonaptera/classification , Horses , Insect Vectors/classification , Polymerase Chain Reaction , Rickettsia Infections/epidemiology , Rickettsia Infections/microbiology , Rickettsia Infections/transmission , Rickettsia felis/isolation & purification , Ticks/classification
11.
Mem. Inst. Oswaldo Cruz ; 102(7): 793-801, Nov. 2007. mapas, tab
Article in English | LILACS | ID: lil-470345

ABSTRACT

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.


Subject(s)
Animals , Cats , Dogs , Humans , Endemic Diseases , Rickettsia Infections/epidemiology , Antibodies, Bacterial , Brazil/epidemiology , DNA, Bacterial/analysis , Fluorescent Antibody Technique, Indirect , Siphonaptera/microbiology , Horses/microbiology , Opossums/microbiology , Rickettsia Infections/microbiology , Rickettsia Infections/veterinary , Rickettsia/genetics , Rickettsia/immunology , Rickettsia/isolation & purification , Ticks/microbiology
12.
Mem. Inst. Oswaldo Cruz ; 100(8): 841-845, Dec. 2005. tab
Article in English | LILACS | ID: lil-419949

ABSTRACT

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


Subject(s)
Animals , Cattle , Dogs , Female , Humans , Male , Endemic Diseases , Ixodidae/microbiology , Rickettsia Infections/microbiology , Rickettsia rickettsii/isolation & purification , Brazil/epidemiology , Disease Vectors , Horses , Hemolymph/microbiology , Polymerase Chain Reaction , Rickettsia Infections/epidemiology , Rickettsia rickettsii/genetics
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