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Sample records for carry flea-borne rickettsia

  1. Flea-Borne Rickettsioses and Rickettsiae

    PubMed Central

    Blanton, Lucas S.; Walker, David H.

    2017-01-01

    Rickettsia typhi and Rickettsia felis are flea-borne rickettsiae that are distributed throughout the world. This mini-review outlines the ecology and epidemiology of flea-borne rickettsioses; highlights important clinical, diagnostic, and therapeutic considerations; and discusses areas of uncertainty regarding Rickettsia felis and other rickettsiae harbored by fleas. PMID:27799640

  2. Flea-Borne Rickettsioses and Rickettsiae.

    PubMed

    Blanton, Lucas S; Walker, David H

    2017-01-11

    Rickettsia typhi and Rickettsia felis are flea-borne rickettsiae that are distributed throughout the world. This mini-review outlines the ecology and epidemiology of flea-borne rickettsioses; highlights important clinical, diagnostic, and therapeutic considerations; and discusses areas of uncertainty regarding Rickettsia felis and other rickettsiae harbored by fleas. © The American Society of Tropical Medicine and Hygiene.

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

    PubMed

    Chahota, R; Thakur, S D; Sharma, M; Mittra, S

    2015-01-01

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

  4. Limited Evidence for Rickettsia felis as a Cause of Zoonotic Flea-Borne Rickettsiosis in Southern California.

    PubMed

    Billeter, Sarah A; Metzger, Marco E

    2017-01-01

    Over 90% of human flea-borne rickettsioses cases in California are reported from suburban communities of Los Angeles and Orange counties and are presumed to be associated with either Rickettsia typhi or Rickettsia felis infection. Ctenocephalides felis (Bouché) is considered the principal vector for both rickettsiae, and R. felis has largely replaced R. typhi as the presumptive etiologic agent based on the widespread incidence of R. felis in cat flea populations. However, with no evidence to confirm R. felis as the cause of human illness in southern California, coupled with recent findings that showed R. felis to be widespread in cat fleas statewide, we propose that this hypothesis should be reconsidered. Evidence of only limited numbers of R. typhi-infected cat fleas in the environment may indicate a very rare infection and explain why so few cases of flea-borne rickettsioses are reported each year in southern California relative to the population. © 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.

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

    PubMed

    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.

  6. Transmission of flea-borne zoonotic agents.

    PubMed

    Eisen, Rebecca J; Gage, Kenneth L

    2012-01-01

    Flea-borne zoonoses such as plague (Yersinia pestis) and murine typhus (Rickettsia typhi) caused significant numbers of human cases in the past and remain a public health concern. Other flea-borne human pathogens have emerged recently (e.g., Bartonella henselae, Rickettsia felis), and their mechanisms of transmission and impact on human health are not fully understood. Our review focuses on the ecology and epidemiology of the flea-borne bacterial zoonoses mentioned above with an emphasis on recent advancements in our understanding of how these organisms are transmitted by fleas, maintained in zoonotic cycles, and transmitted to humans. Emphasis is given to plague because of the considerable number of studies generated during the first decade of the twenty-first century that arose, in part, because of renewed interest in potential agents of bioterrorism, including Y. pestis.

  7. Fatal Flea-Borne Typhus in Texas: A Retrospective Case Series, 1985-2015.

    PubMed

    Pieracci, Emily G; Evert, Nicole; Drexler, Naomi A; Mayes, Bonny; Vilcins, Inger; Huang, Philip; Campbell, Jill; Behravesh, Casey Barton; Paddock, Christopher D

    2017-05-01

    AbstractFlea-borne (murine) typhus is a global rickettsiosis caused by Rickettsia typhi. Although flea-borne typhus is no longer nationally notifiable, cases are reported for surveillance purposes in a few U.S. states. The infection is typically self-limiting, but may be severe or life-threatening in some patients. We performed a retrospective review of confirmed or probable cases of fatal flea-borne typhus reported to the Texas Department of State Health Services during 1985-2015. When available, medical charts were also examined. Eleven cases of fatal flea-borne typhus were identified. The median patient age was 62 years (range, 36-84 years) and 8 (73%) were male. Patients presented most commonly with fever (100%), nausea and vomiting (55%), and rash (55%). Respiratory (55%) and neurologic (45%) manifestations were also identified frequently. Laboratory abnormalities included thrombocytopenia (82%) and elevated hepatic transaminases (63%). Flea or animal contact before illness onset was frequently reported (55%). The median time from hospitalization to administration of a tetracycline-class drug was 4 days (range, 0-5 days). The median time from symptom onset to death was 14 days (range, 1-34 days). Flea-borne typhus can be a life-threatening disease if not treated in a timely manner with appropriate tetracycline-class antibiotics. Flea-borne typhus should be considered in febrile patients with animal or flea exposure and respiratory or neurologic symptoms of unknown etiology.

  8. Fleas and flea-borne diseases.

    PubMed

    Bitam, Idir; Dittmar, Katharina; Parola, Philippe; Whiting, Michael F; Raoult, Didier

    2010-08-01

    Flea-borne infections are emerging or re-emerging throughout the world, and their incidence is on the rise. Furthermore, their distribution and that of their vectors is shifting and expanding. This publication reviews general flea biology and the distribution of the flea-borne diseases of public health importance throughout the world, their principal flea vectors, and the extent of their public health burden. Such an overall review is necessary to understand the importance of this group of infections and the resources that must be allocated to their control by public health authorities to ensure their timely diagnosis and treatment.

  9. Tick- and flea-borne rickettsial emerging zoonoses.

    PubMed

    Parola, Philippe; Davoust, Bernard; Raoult, Didier

    2005-01-01

    Between 1984 and 2004, nine more species or subspecies of spotted fever rickettsiae were identified as emerging agents of tick-borne rickettsioses throughout the world. Six of these species had first been isolated from ticks and later found to be pathogenic to humans. The most recent example is Rickettsia parkeri, recognized as a human pathogen more than 60 years after its initial isolation from ticks. A new spotted fever rickettsia, R. felis was also found to be associated with fleas and to be a human pathogen. Similarly, bacteria within the family Anaplasmataceae have been considered to be of veterinary importance only, yet three species have been implicated in human diseases in recent years, including Ehrlichia chaffeensis, the agent of human monocytic ehrlichiosis, Anaplasma phagocytophilum, the agent of human anaplasmosis (formerly known as "human granulocytic ehrlichiosis agent", E. equi and E. phagocytophila), and finally Ehrlichia ewingii, which causes granulocytic ehrlichiosis in humans. We present here an overview of the various tick- and flea-borne rickettsial zoonoses described in the last 20 years, focusing on the ecological, epidemiological and clinical aspects.

  10. Flea-Borne Rickettsioses in the North of Caldas Province, Colombia

    PubMed Central

    Montoya, Viviana; Martínez, Alejandra; Mercado, Marcela; De la Ossa, Alberto; Vélez, Carolina; Estrada, Gloria; Pérez, Jorge E.; Faccini-Martínez, Alvaro A.; Labruna, Marcelo B.; Valbuena, Gustavo

    2013-01-01

    Abstract Rickettsia typhi and R. felis are the etiological agents of murine typhus and flea-borne spotted fever, respectively. Both are emerging acute febrile zoonotic diseases for which fleas are vectors; they also have similar clinical characteristics and global distribution. In 2005, we identified the circulation of murine typhus in 6 towns within the mountainous coffee-growing area north of Caldas, Colombia. We now report the specific seroprevalence against R. typhi and R. felis, and associated risk factors in 7 towns of this province. The combined seroprevalence against the 2 flea-borne rickettsioses is the highest yet reported in the literature: 71.7% (17.8% for R. felis, 25.2% for R. typhi, and 28.7% for both). We also report a prospective analysis of 26 patients with a febrile illness compatible with rickettsioses, including murine typhus; 9 of these patients had a rickettsiosis. This supports our sero-epidemiological results and highlights the diagnostic complexity of febrile syndromes in this region. PMID:23473218

  11. Rickettsial Infections among Ctenocephalides felis and Host Animals during a Flea-Borne Rickettsioses Outbreak in Orange County, California

    PubMed Central

    Fogarty, Carrie; Krueger, Laura; Macaluso, Kevin R.; Odhiambo, Antony; Nguyen, Kiet; Farris, Christina M.; Luce-Fedrow, Alison; Bennett, Stephen; Jiang, Ju; Sun, Sokanary; Cummings, Robert F.; Richards, Allen L.

    2016-01-01

    Due to a resurgence of flea-borne rickettsioses in Orange County, California, we investigated the etiologies of rickettsial infections of Ctenocephalides felis, the predominant fleas species obtained from opossums (Didelphis virginiana) and domestic cats (Felis catus), collected from case exposure sites and other areas in Orange County. In addition, we assessed the prevalence of IgG antibodies against spotted fever group (SFGR) and typhus group (TGR) rickettsiae in opossum sera. Of the 597 flea specimens collected from opossums and cats, 37.2% tested positive for Rickettsia. PCR and sequencing of rickettsial genes obtained from C. felis flea DNA preparations revealed the presence of R. typhi (1.3%), R. felis (28.0%) and R. felis-like organisms (7.5%). Sera from opossums contained TGR-specific (40.84%), but not SFGR-specific antibodies. The detection of R. felis and R. typhi in the C. felis fleas in Orange County highlights the potential risk for human infection with either of these pathogens, and underscores the need for further investigations incorporating specimens from humans, animal hosts, and invertebrate vectors in endemic areas. Such studies will be essential for establishing a link in the ongoing flea-borne rickettsioses outbreaks. PMID:27537367

  12. Flea-associated zoonotic diseases of cats in the USA: bartonellosis, flea-borne rickettsioses, and plague.

    PubMed

    McElroy, Kristina M; Blagburn, Byron L; Breitschwerdt, Edward B; Mead, Paul S; McQuiston, Jennifer H

    2010-04-01

    Cat-scratch disease, flea-borne typhus, and plague are three flea-associated zoonoses of cats of concern in the USA. Although flea concentrations may be heaviest in coastal and temperate climates, fleas and flea-borne disease agents can occur almost anywhere in the USA. Understanding flea-borne pathogens, and the associated risks for owners and veterinarians, is important to reduce the likelihood of zoonotic infection.

  13. Louse- and flea-borne rickettsioses: biological and genomic analyses

    PubMed Central

    Gillespie, Joseph J.; Ammerman, Nicole C.; Beier-Sexton, Magda; Sobral, Bruno S.; Azad, Abdu F.

    2009-01-01

    In contrast to 15 or more validated and/or proposed tick-borne spotted fever group species, only three named medically important rickettsial species are associated with insects. These insect-borne rickettsiae are comprised of two highly pathogenic species, Rickettsia prowazekii (the agent of epidemic typhus) and R. typhi (the agent of murine typhus), as well as R. felis, a species with unconfirmed pathogenicity. Rickettsial association with obligate hematophagous insects such as the human body louse (R. prowazekii transmitted by Pediculus h. humanus) and several flea species (R. typhi and R. felis, as well as R. prowazekii in sylvatic form) provides rickettsiae the potential for further multiplications, longer transmission cycles and rapid spread among susceptible human populations. Both human body lice and fleas are intermittent feeders capable of multiple blood meals per generation, facilitating the efficient transmission of rickettsiae to several disparate hosts within urban/rural ecosystems. While taking into consideration the existing knowledge of rickettsial biology and genomic attributes, we have analyzed and summarized the interacting features that are unique to both the rickettsiae and their vector fleas and lice. Furthermore, factors that underlie rickettsial changing ecology, where native mammalian populations are involved in the maintenance of rickettsial cycle and transmission, are discussed. PMID:19036234

  14. "Candidatus Rickettsia asemboensis" in Rhipicephalus sanguineus ticks, Brazil.

    PubMed

    Dall'Agnol, Bruno; Souza, Ugo; Webster, Anelise; Weck, Bárbara; Stenzel, Bárbara; Labruna, Marcelo; Klafke, Guilherme; Martins, João Ricardo; Ferreira, Carlos Alexandre Sanchez; Reck, José

    2017-03-01

    "Candidatus Rickettsia asemboensis" is an obligate intracellular bacterium of the Rickettsiales order, genetically related to species belonging to the Rickettsia felis group, agents of flea-borne spotted fever. Here we report for the first time the detection of "Ca. R. asemboensis", a flea-associated organism, in Rhipicephalus sanguineus ticks. It is the first occurrence of this emerging bacterium in Brazil, which increases the geographical distribution of this R. felis-like agent.

  15. Bartonella clarridgeiae, B. henselae and Rickettsia felis in fleas from Morocco.

    PubMed

    Boudebouch, N; Sarih, M; Beaucournu, J-C; Amarouch, H; Hassar, M; Raoult, D; Parola, P

    2011-10-01

    A total of 554 fleas were collected in the Moroccan Casablanca and Tiznit regions from domesticated animals and ruminants between August 2007 and October 2008 and were tested for the presence of Rickettsia spp. and Bartonella spp. using molecular methods. For the first time in Morocco, we found Rickettsia felis, the agent of flea-borne spotted fever in Ctenocephalides felis; B. henselae, an agent of cat scratch disease; and Bartonella clarridgeiae, a cat pathogen and potentially a human pathogen.

  16. Bartonella clarridgeiae, B. henselae and Rickettsia felis in fleas from Morocco

    PubMed Central

    BOUDEBOUCH, N; SARIH, M; BEAUCOURNU, J-C; AMAROUCH, H; HASSAR, M; RAOULT, D; PAROLA, P

    2011-01-01

    A total of 554 fleas were collected in the Moroccan Casablanca and Tiznit regions from domesticated animals and ruminants between August 2007 and October 2008 and were tested for the presence of Rickettsia spp. and Bartonella spp. using molecular methods. For the first time in Morocco, we found Rickettsia felis, the agent of flea-borne spotted fever in Ctenocephalides felis; B. henselae, an agent of cat scratch disease; and Bartonella clarridgeiae, a cat pathogen and potentially a human pathogen. PMID:22185943

  17. Rickettsia felis and Bartonella henselae in fleas from Lebanon.

    PubMed

    Mba, Pamela Angue; Marié, Jean-Lou; Rolain, Jean-Marc; Davoust, Bernard; Beaucournu, Jean-Claude; Raoult, Didier; Parola, Philippe

    2011-07-01

    A total of 155 fleas collected in 2009 in Lebanon from 16 cats (104 Ctenocephalides felis specimens, 1 C. canis specimen) and 2 dogs (50 C. canis specimens) were tested for the presence of Rickettsia spp. and Bartonella spp. using molecular methods, including real-time quantitative polymerase chain reaction (PCR), regular PCR, and sequencing of amplified PCR products. Rickettsia felis, the agent of the emerging flea-borne spotted fever in humans, was identified in 17 (16%) C. felis cat fleas. Bartonella henselae, an agent of cat scratch disease, was identified in three (2.9%) C. felis. Our results emphasize the potential risk of these emerging flea-borne infections in Lebanon.

  18. Retracing the Evolutionary Path that Led to Flea-borne Transmission of Yersinia pestis

    PubMed Central

    Sun, Yi-Cheng; Jarrett, Clayton O.; Bosio, Christopher F.; Hinnebusch, B. Joseph

    2014-01-01

    Summary Yersinia pestis is an arthropod-borne bacterial pathogen that evolved recently from Yersinia pseudotuberculosis, an enteric pathogen transmitted via the fecal-oral route. This radical ecological transition can be attributed to a few discrete genetic changes from a still-extant recent ancestor, thus providing a tractable case study in pathogen evolution and emergence. Here, we determined the precise genetic and mechanistic basis of the evolutionary adaptation of Y. pestis to flea-borne transmission. Remarkably, only four minor changes in the bacterial progenitor, representing one gene gain and three gene losses, enabled transmission by flea vectors. All three loss-of-function mutations enhanced c-di-GMP-mediated bacterial biofilm formation in the flea foregut that greatly increased transmissibility. Our results suggest a step-wise evolutionary model in which Y. pestis emerged as a flea-borne clone, with each genetic change incrementally reinforcing the transmission cycle. The model conforms well to the ecological theory of adaptive radiation. PMID:24832452

  19. Retracing the evolutionary path that led to flea-borne transmission of Yersinia pestis.

    PubMed

    Sun, Yi-Cheng; Jarrett, Clayton O; Bosio, Christopher F; Hinnebusch, B Joseph

    2014-05-14

    Yersinia pestis is an arthropod-borne bacterial pathogen that evolved recently from Yersinia pseudotuberculosis, an enteric pathogen transmitted via the fecal-oral route. This radical ecological transition can be attributed to a few discrete genetic changes from a still-extant recent ancestor, thus providing a tractable case study in pathogen evolution and emergence. Here, we determined the genetic and mechanistic basis of the evolutionary adaptation of Y. pestis to flea-borne transmission. Remarkably, only four minor changes in the bacterial progenitor, representing one gene gain and three gene losses, enabled transmission by flea vectors. All three loss-of-function mutations enhanced cyclic-di-GMP-mediated bacterial biofilm formation in the flea foregut, which greatly increased transmissibility. Our results suggest a step-wise evolutionary model in which Y. pestis emerged as a flea-borne clone, with each genetic change incrementally reinforcing the transmission cycle. The model conforms well to the ecological theory of adaptive radiation. Copyright © 2014 Elsevier Inc. All rights reserved.

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

    PubMed Central

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

    2013-01-01

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

  1. Ecological Opportunity, Evolution, and the Emergence of Flea-Borne Plague.

    PubMed

    Hinnebusch, B Joseph; Chouikha, Iman; Sun, Yi-Cheng

    2016-07-01

    The plague bacillus Yersinia pestis is unique among the pathogenic Enterobacteriaceae in utilizing an arthropod-borne transmission route. Transmission by fleabite is a recent evolutionary adaptation that followed the divergence of Y. pestis from the closely related food- and waterborne enteric pathogen Yersinia pseudotuberculosis A combination of population genetics, comparative genomics, and investigations of Yersinia-flea interactions have disclosed the important steps in the evolution and emergence of Y. pestis as a flea-borne pathogen. Only a few genetic changes, representing both gene gain by lateral transfer and gene loss by loss-of-function mutation (pseudogenization), were fundamental to this process. The emergence of Y. pestis fits evolutionary theories that emphasize ecological opportunity in adaptive diversification and rapid emergence of new species. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  2. Ecological Opportunity, Evolution, and the Emergence of Flea-Borne Plague

    PubMed Central

    Chouikha, Iman; Sun, Yi-Cheng

    2016-01-01

    The plague bacillus Yersinia pestis is unique among the pathogenic Enterobacteriaceae in utilizing an arthropod-borne transmission route. Transmission by fleabite is a recent evolutionary adaptation that followed the divergence of Y. pestis from the closely related food- and waterborne enteric pathogen Yersinia pseudotuberculosis. A combination of population genetics, comparative genomics, and investigations of Yersinia-flea interactions have disclosed the important steps in the evolution and emergence of Y. pestis as a flea-borne pathogen. Only a few genetic changes, representing both gene gain by lateral transfer and gene loss by loss-of-function mutation (pseudogenization), were fundamental to this process. The emergence of Y. pestis fits evolutionary theories that emphasize ecological opportunity in adaptive diversification and rapid emergence of new species. PMID:27160296

  3. Role of the Yersinia pestis yersiniabactin iron acquisition system in the incidence of flea-borne plague.

    PubMed

    Sebbane, Florent; Jarrett, Clayton; Gardner, Donald; Long, Daniel; Hinnebusch, B Joseph

    2010-12-17

    Plague is a flea-borne zoonosis caused by the bacterium Yersinia pestis. Y. pestis mutants lacking the yersiniabactin (Ybt) siderophore-based iron transport system are avirulent when inoculated intradermally but fully virulent when inoculated intravenously in mice. Presumably, Ybt is required to provide sufficient iron at the peripheral injection site, suggesting that Ybt would be an essential virulence factor for flea-borne plague. Here, using a flea-to-mouse transmission model, we show that a Y. pestis strain lacking the Ybt system causes fatal plague at low incidence when transmitted by fleas. Bacteriology and histology analyses revealed that a Ybt-negative strain caused only primary septicemic plague and atypical bubonic plague instead of the typical bubonic form of disease. The results provide new evidence that primary septicemic plague is a distinct clinical entity and suggest that unusual forms of plague may be caused by atypical Y. pestis strains.

  4. Role of the Yersinia pestis Yersiniabactin Iron Acquisition System in the Incidence of Flea-Borne Plague

    PubMed Central

    Sebbane, Florent; Jarrett, Clayton; Gardner, Donald; Long, Daniel; Hinnebusch, B. Joseph

    2010-01-01

    Plague is a flea-borne zoonosis caused by the bacterium Yersinia pestis. Y. pestis mutants lacking the yersiniabactin (Ybt) siderophore-based iron transport system are avirulent when inoculated intradermally but fully virulent when inoculated intravenously in mice. Presumably, Ybt is required to provide sufficient iron at the peripheral injection site, suggesting that Ybt would be an essential virulence factor for flea-borne plague. Here, using a flea-to-mouse transmission model, we show that a Y. pestis strain lacking the Ybt system causes fatal plague at low incidence when transmitted by fleas. Bacteriology and histology analyses revealed that a Ybt-negative strain caused only primary septicemic plague and atypical bubonic plague instead of the typical bubonic form of disease. The results provide new evidence that primary septicemic plague is a distinct clinical entity and suggest that unusual forms of plague may be caused by atypical Y. pestis strains. PMID:21179420

  5. Flea-borne transmission model to evaluate vaccine efficacy against naturally acquired bubonic plague.

    PubMed

    Jarrett, Clayton O; Sebbane, Florent; Adamovicz, Jeffrey J; Andrews, Gerard P; Hinnebusch, B Joseph

    2004-04-01

    A flea-to-mouse transmission model was developed for use in testing new candidate vaccines for the ability to protect against flea-borne plague. The model was used to evaluate a recombinant fusion protein vaccine consisting of the Yersinia pestis F1 and V antigens. After one to three challenges with Y. pestis-infected fleas, 14 of 15 unvaccinated control mice developed plague, with an average septicemia level of 9.2 x 10(8) Y. pestis CFU/ml. None of 15 vaccinated mice developed the disease after similar challenges, and serological testing indicated that transmitted bacteria were eliminated by the immune system before extensive replication and systemic infection could occur. The transmission and development of disease in control mice correlated with the number of bites by blocked fleas but not with the total number of fleabites. The model provides a means to directly assess the efficacy of new vaccines to prevent naturally acquired bubonic plague and to study events at the vector-host interface that lead to dissemination and disease.

  6. Anthropogenic disturbance and the risk of flea-borne disease transmission.

    PubMed

    Friggens, Megan M; Beier, Paul

    2010-11-01

    Anthropogenic disturbance may lead to the spread of vector-borne diseases through effects on pathogens, vectors, and hosts. Identifying the type and extent of vector response to habitat change will enable better and more accurate management strategies for anthropogenic disease spread. We compiled and analyzed data from published empirical studies to test for patterns among flea and small mammal diversity, abundance, several measures of flea infestation, and host specificity in 70 small mammal communities of five biomes and three levels of human disturbance: remote/wild areas, agricultural areas, and urban areas. Ten of 12 mammal and flea characteristics showed a significant effect of disturbance category (six), biome (four), or both (two). Six variables had a significant interaction effect. For mammal-flea communities in forest habitats (39 of the 70 communities), disturbance affected all 12 characteristics. Overall, flea and mammal richness were higher in remote versus urban sites. Most measures of flea infestation, including percent of infested mammals and fleas/mammal and fleas/mammal species increased with increasing disturbance or peaked at intermediate levels of disturbance. In addition, host use increased, and the number of specialist fleas decreased, as human disturbance increased. Of the three most common biomes (forest, grassland/savanna, desert), deserts were most sensitive to disturbance. Finally, sites of intermediate disturbance were most diverse and exhibited characteristics associated with increased disease spread. Anthropogenic disturbance was associated with conditions conducive to increased transmission of flea-borne diseases.

  7. Genomic Diversification in Strains of Rickettsia felis Isolated from Different Arthropods

    PubMed Central

    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

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

    PubMed

    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.

  9. Rickettsia felis and Bartonella spp. in fleas from cats in Albania.

    PubMed

    Silaghi, Cornelia; Knaus, Martin; Rapti, Dhimiter; Shukullari, Enstela; Pfister, Kurt; Rehbein, Steffen

    2012-01-01

    Fleas can serve as vectors for bacterial pathogens like Bartonella and Rickettsia species, which have been isolated worldwide. However, the knowledge of the epidemiology of vector-borne diseases in general and thus on flea-borne diseases in Albania is limited. Therefore, from 78 free-roaming cats in Tirana, Albania, fleas (371 Ctenocephalides felis and 5 Ctenocephalides canis) were collected to examine them for the presence of Rickettsia and Bartonella species. Ten of the 371 C. felis (2.7%) were positive for Rickettsia felis, and 24 (6.5%) for Bartonella spp. (B. henselae and B. clarridgeiae). In total, fleas from 15 cats (19.2%) were positive for either one or the other of the pathogens. The results of this study provided evidence for the presence of R. felis (causing flea-borne spotted fever) and Bartonella spp. (causing cat scratch disease) in Albania. Thus, these infectious diseases should be considered as differential diagnoses when febrile symptoms are presented, especially after contact with cats or their fleas.

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

    PubMed

    Houhamdi, Linda; Raoult, Didier

    2006-04-01

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

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

    PubMed Central

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

    2011-01-01

    Rickettsia felis was first recognised two decades ago and has now been described as endemic to all continents except Antarctica. The rickettsiosis caused by R. felis is known as flea-borne spotted fever or cat-flea typhus. The large number of arthropod species found to harbour R. felis and that may act as potential vectors support the view that it is a pan-global microbe. The main arthropod reservoir and vector is the cat flea, Ctenocephalides felis, yet more than 20 other species of fleas, ticks, and mites species have been reported to harbour R. felis. Few bacterial pathogens of humans have been found associated with such a diverse range of invertebrates. With the projected increase in global temperature over the next century, there is concern that changes to the ecology and distribution of R. felis vectors may adversely impact public health. PMID:24149035

  12. Serological evidence of exposure to Rickettsia felis and Rickettsia typhi in Australian veterinarians.

    PubMed

    Teoh, Yen Thon; Hii, Sze Fui; Stevenson, Mark A; Graves, Stephen; Rees, Robert; Stenos, John; Traub, Rebecca J

    2017-03-13

    Rickettsia felis and Rickettsia typhi are emerging arthropod-borne zoonoses causing fever and flu-like symptoms. Seroprevalence and risk factors associated with exposure to these organisms was explored in Australian veterinarians. One hundred and thirty-one veterinarians from across Australia were recruited to participate in a cross-sectional survey. Veterinarians provided a single blood sample and answered a questionnaire on potential risk factors influencing their exposure to R. felis and R. typhi. Indirect microimmunofluorescence antibody testing (IFAT) was used to identify evidence of serological exposure of the participants to R. felis and R. typhi. Results were analyzed and a logistical regression model performed to predict risk factors associated with seropositivity. In total, 16.0% of participants were seropositive to R. felis, 4.6% to R. typhi and 35.1% seropositive to both, where cross-reactivity of the IFAT between R. felis and R. typhi precluded a definitive diagnosis. Veterinarians residing within the south-eastern states of Victoria and Tasmania were at a higher risk of exposure to R. felis or generalised R. felis or R. typhi exposure. Older veterinarians and those that recommended flea treatment to their clients were found to be significantly protected from exposure. The high exposure to R. felis amongst veterinary professionals suggests that flea-borne spotted fever is an important cause of undifferentiated fever conditions that may not be adequately recognized in Australia.

  13. Role of the Yersinia pestis plasminogen activator in the incidence of distinct septicemic and bubonic forms of flea-borne plague.

    PubMed

    Sebbane, Florent; Jarrett, Clayton O; Gardner, Donald; Long, Daniel; Hinnebusch, B Joseph

    2006-04-04

    Yersinia pestis is transmitted by fleas and causes bubonic plague, characterized by severe local lymphadenitis that progresses rapidly to systemic infection and life-threatening septicemia. Here, we show that although flea-borne transmission usually leads to bubonic plague in mice, it can also lead to primary septicemic plague. However, intradermal injection of Y. pestis, commonly used to mimic transmission by fleabite, leads only to bubonic plague. A Y. pestis strain lacking the plasmid-encoded cell-surface plasminogen activator, which is avirulent by intradermal or s.c. injection, was able to cause fatal primary septicemic plague at low incidence, but not bubonic plague, when transmitted by fleas. The results clarify a long-standing uncertainty about the etiology of primary septicemic plague and support an evolutionary scenario in which plague first emerged as a flea-borne septicemic disease of limited transmissibility. Subsequent acquisition of the plasminogen activator gene by horizontal transfer enabled the bubonic form of disease and increased the potential for epidemic spread.

  14. Role of the Yersinia pestis plasminogen activator in the incidence of distinct septicemic and bubonic forms of flea-borne plague

    PubMed Central

    Sebbane, Florent; Jarrett, Clayton O.; Gardner, Donald; Long, Daniel; Hinnebusch, B. Joseph

    2006-01-01

    Yersinia pestis is transmitted by fleas and causes bubonic plague, characterized by severe local lymphadenitis that progresses rapidly to systemic infection and life-threatening septicemia. Here, we show that although flea-borne transmission usually leads to bubonic plague in mice, it can also lead to primary septicemic plague. However, intradermal injection of Y. pestis, commonly used to mimic transmission by fleabite, leads only to bubonic plague. A Y. pestis strain lacking the plasmid-encoded cell-surface plasminogen activator, which is avirulent by intradermal or s.c. injection, was able to cause fatal primary septicemic plague at low incidence, but not bubonic plague, when transmitted by fleas. The results clarify a long-standing uncertainty about the etiology of primary septicemic plague and support an evolutionary scenario in which plague first emerged as a flea-borne septicemic disease of limited transmissibility. Subsequent acquisition of the plasminogen activator gene by horizontal transfer enabled the bubonic form of disease and increased the potential for epidemic spread. PMID:16567636

  15. Molecular detection of Bartonella quintana, B. Elizabethae, B. Koehlerae, B. Doshiae, B. Taylorii, and Rickettsia felis in rodent fleas collected in Kabul, Afghanistan.

    PubMed

    Marié, Jean-Lou; Fournier, Pierre-Edouard; Rolain, Jean-Marc; Briolant, Sébastien; Davoust, Bernard; Raoult, Didier

    2006-03-01

    The prevalences of Bartonella spp. and Rickettsia spp. were investigated using molecular methods in 77 rodent fleas collected in November 2002 by the French forces detachment in Kabul, Afghanistan. Overall, Bartonella DNA was detected in 15.5% of gerbil fleas and 40.5% of rat fleas, whereas Rickettsia felis was found in 9% of gerbil fleas. We described for the first time in this country Bartonella quintana, B. koehlerae, B. taylorii, and Rickettsia felis in fleas from the gerbil species Meriones lybicus, and B. elizabethae and B. doshiae in rat fleas. Of these, B. quintana, B. elizabethae, B. koehlerae, and R. felis are recognized human pathogens. These results emphasize the potential risk of flea-borne infections transmitted by rodents in this area, and suggest that preventive measures should be taken in the general framework of zoonoses management.

  16. Ecology of Rickettsia felis: a review.

    PubMed

    Reif, Kathryn E; Macaluso, Kevin R

    2009-07-01

    It has been two decades since the first description of Rickettsia felis, and although a nearly cosmopolitan distribution is now apparent, much of the ecology of this unique microorganism remains unresolved. The cat flea, Ctenocephalides felis, is currently the only known biological vector of R. felis; however, molecular evidence of R. felis in other species of fleas as well as in ticks and mites suggests a variety of arthropod hosts. Studies examining the transmission of R. felis using colonized cat fleas have shown stable vertical transmission but not horizontal transmission. Likewise, serological and molecular tools have been used to detect R. felis in a number of vertebrate hosts, including humans, in the absence of a clear mechanism of horizontal transmission. Considered an emerging flea-borne rickettsiosis, clinical manifestation of R. felis infection in humans, including, fever, rash, and headache is similar to other rickettsial diseases. Recent advances toward further understanding the ecology of R. felis have been facilitated by stable R. felis-infected cat flea colonies, several primary flea isolates and sustained maintenance of R. felis in cell culture systems, and highly sensitive quantitative molecular assays. Here, we provide a synopsis of R. felis including the known distribution and arthropods infected; transmission mechanisms; current understanding of vertebrate infection and human disease; and the tools available to further examine R. felis.

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

    PubMed

    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.

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

    PubMed Central

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

    2014-01-01

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

  19. Prevalence of Bartonella species, hemoplasmas, and Rickettsia felis DNA in blood and fleas of cats in Bangkok, Thailand.

    PubMed

    Assarasakorn, S; Veir, J K; Hawley, J R; Brewer, M M; Morris, A K; Hill, A E; Lappin, M R

    2012-12-01

    Flea infestations are common in Thailand, but little is known about the flea-borne infections. Fifty flea pools and 153 blood samples were collected from client-owned cats between June and August 2009 from veterinary hospitals in Bangkok, Thailand. Total DNA was extracted from all samples, and then assessed by conventional PCR assays. The prevalence rates of Bartonella spp. in blood and flea samples were 17% and 32%, respectively, with DNA of Bartonella henselae and Bartonella clarridgeiae being amplified most commonly. Bartonella koehlerae DNA was amplified for the first time in Thailand. Hemoplasma DNA was amplified from 23% and 34% of blood samples and flea pools, respectively, with 'Candidatus Mycoplasma haemominutum' and Mycoplasma haemofelis being detected most frequently. All samples were negative for Rickettsia felis. Prevalence rate of B. henselae DNA was increased 6.9 times in cats with flea infestation. Cats administered flea control products were 4.2 times less likely to be Bartonella-infected.

  20. Rickettsia and Bartonella species in fleas from Reunion Island.

    PubMed

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

    2015-03-01

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

  1. Rickettsia and Bartonella Species in Fleas from Reunion Island

    PubMed Central

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

    2015-01-01

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

  2. Rickettsia africae and Candidatus Rickettsia barbariae in Ticks in Israel

    PubMed Central

    Waner, Trevor; Keysary, Avi; Eremeeva, Marina E.; Din, Adi Beth; Mumcuoglu, Kosta Y.; King, Roni; Atiya-Nasagi, Yafit

    2014-01-01

    DNA of several spotted fever group rickettsiae was found in ticks in Israel. The findings include evidence for the existence of Rickettsia africae and Candidatus Rickettsia barbariae in ticks in Israel. The DNA of R. africae was detected in a Hyalomma detritum tick from a wild boar and DNA of C. Rickettsia barbariae was detected in Rhipicephalus turanicus and Rhipicephalus sanguineus collected from vegetation. The DNA of Rickettsia massiliae was found in Rh. sanguineus and Haemaphysalis erinacei, whereas DNA of Rickettsia sibirica mongolitimonae was detected in a Rhipicephalus (Boophilus) annulatus. Clinicians should be aware that diseases caused by a variety of rickettsiae previously thought to be present only in other countries outside of the Middle East may infect residents of Israel who have not necessarily traveled overseas. Furthermore, this study reveals again that the epidemiology of the spotted fever group rickettsiae may not only involve Rickettsia conorii but may include other rickettsiae. PMID:24615133

  3. Detection of Rickettsia hoogstraalii, Rickettsia helvetica, Rickettsia massiliae, Rickettsia slovaca and Rickettsia aeschlimannii in ticks from Sardinia, Italy.

    PubMed

    Chisu, Valentina; Leulmi, Hamza; Masala, Giovanna; Piredda, Mariano; Foxi, Cipriano; Parola, Philippe

    2017-03-01

    Tick-borne diseases represent a large proportion of infectious diseases that have become a world health concern. The presence of Rickettsia spp. was evaluated by standard PCR and sequencing in 123 ticks collected from several mammals and vegetation in Sardinia, Italy. This study provides the first evidence of the presence of Rickettsia hoogstralii in Haemaphysalis punctata and Haemaphysalis sulcata ticks from mouflon and Rickettsia helvetica in Ixodes festai ticks from hedgehog. In addition, Rickettsia massiliae, Rickettsia slovaca and Rickettsia aeschlimannii were detected in Rhipicephalus sanguineus, Dermacentor marginatus and Hyalomma marginatum marginatum ticks from foxes, swine, wild boars, and mouflon. The data presented here increase our knowledge of tick-borne diseases in Sardinia and provide a useful contribution toward understanding their epidemiology. Copyright © 2016 Elsevier GmbH. All rights reserved.

  4. Tropism and Pathogenicity of Rickettsiae

    PubMed Central

    Uchiyama, Tsuneo

    2012-01-01

    Rickettsiae are obligate intracellular parasitic bacteria that cause febrile exanthematous illnesses such as Rocky Mountain spotted fever, Mediterranean spotted fever, epidemic, and murine typhus, etc. Although the vector ranges of each Rickettsia species are rather restricted; i.e., ticks belonging to Arachnida and lice and fleas belonging to Insecta usually act as vectors for spotted fever group (SFG) and typhus group (TG) rickettsiae, respectively, it would be interesting to elucidate the mechanisms controlling the vector tropism of rickettsiae. This review discusses the factors determining the vector tropism of rickettsiae. In brief, the vector tropism of rickettsiae species is basically consistent with their tropism toward cultured tick and insect cells. The mechanisms responsible for rickettsiae pathogenicity are also described. Recently, genomic analyses of rickettsiae have revealed that they possess several genes that are homologous to those affecting the pathogenicity of other bacteria. Analyses comparing the genomes of pathogenic and non-pathogenic strains of rickettsiae have detected many factors that are related to rickettsial pathogenicity. It is also known that a reduction in the rickettsial genome has occurred during the course of its evolution. Interestingly, Rickettsia species with small genomes, such as Rickettsia prowazekii, are more pathogenic to humans than those with larger genomes. This review also examines the growth kinetics of pathogenic and non-pathogenic species of SFG rickettsiae (SFGR) in mammalian cells. The growth of non-pathogenic species is restricted in these cells, which is mediated, at least in part, by autophagy. The superinfection of non-pathogenic rickettsiae-infected cells with pathogenic rickettsiae results in an elevated yield of the non-pathogenic rickettsiae and the growth of the pathogenic rickettsiae. Autophagy is restricted in these cells. These results are discussed in this review. PMID:22737150

  5. "Candidatus Rickettsia kellyi," India.

    PubMed

    Rolain, Jean-Marc; Mathai, Elizabeth; Lepidi, Hubert; Somashekar, Hosaagrahara R; Mathew, Leni G; Prakash, John A J; Raoult, Didier

    2006-03-01

    We report the first laboratory-confirmed human infection due to a new rickettsial genotype in India, "Candidatus Rickettsia kellyi," in a 1-year-old boy with fever and maculopapular rash. The diagnosis was made by serologic testing, polymerase chain reaction detection, and immunohistochemical testing of the organism from a skin biopsy specimen.

  6. Rickettsia parkeri in Argentina

    PubMed Central

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

    2008-01-01

    Clinical reports of an eschar-associated rickettsiosis in the Paraná River Delta of Argentina prompted an evaluation of Amblyomma triste ticks in this region. When evaluated by PCR, 17 (7.6%) of 223 questing adult A. triste ticks, collected from 2 sites in the lower Paraná River Delta, contained DNA of Rickettsia parkeri. PMID:19046514

  7. Detection of Bartonella tamiae, Coxiella burnetii and rickettsiae in arthropods and tissues from wild and domestic animals in northeastern Algeria.

    PubMed

    Leulmi, Hamza; Aouadi, Atef; Bitam, Idir; Bessas, Amina; Benakhla, Ahmed; Raoult, Didier; Parola, Philippe

    2016-01-20

    In recent years, the scope and importance of emergent vector-borne diseases has increased dramatically. In Algeria, only limited information is currently available concerning the presence and prevalence of these zoonotic diseases. For this reason, we conducted a survey of hematophagous ectoparasites of domestic mammals and/or spleens of wild animals in El Tarf and Souk Ahras, Algeria. Using real-time PCR, standard PCR and sequencing, the presence of Bartonella spp., Rickettsia spp., Borrelia spp. and Coxiella burnetii was evaluated in 268/1626 ticks, 136 fleas, 11 Nycteribiidae flies and 16 spleens of domestic and/or wild animals from the El Tarf and Souk Ahras areas. For the first time in Algeria, Bartonella tamiae was detected in 12/19 (63.2%) Ixodes vespertilionis ticks, 8/11 (72.7%) Nycteribiidae spp. flies and in 6/10 (60%) bat spleens (Chiroptera spp.). DNA from Coxiella burnetii, the agent of Q fever, was also identified in 3/19 (15.8%) I. vespertilionis from bats. Rickettsia slovaca, the agent of tick-borne lymphadenopathy, was detected in 1/1 (100%) Haemaphysalis punctata and 2/3 (66.7%) Dermacentor marginatus ticks collected from two boars (Sus scrofa algira) respectively. Ri. massiliae, an agent of spotted fever, was detected in 38/94 (40.4%) Rhipicephalus sanguineus sensu lato collected from cattle, sheep, dogs, boars and jackals. DNA of Ri. aeschlimannii was detected in 6/20 (30%) Hyalomma anatolicum excavatum and 6/20 (30%) Hy. scupense from cattle. Finally, Ri. felis, an emerging rickettsial pathogen, was detected in 80/110 (72.7%) Archaeopsylla erinacei and 2/2 (100%) Ctenocephalides felis of hedgehogs (Atelerix algirus). In this study, we expanded knowledge about the repertoire of ticks and flea-borne bacteria present in ectoparasites and/or tissues of domestic and wild animals in Algeria.

  8. Novel rickettsia in ticks, Tasmania, Australia.

    PubMed

    Izzard, Leonard; Graves, Stephen; Cox, Erika; Fenwick, Stan; Unsworth, Nathan; Stenos, John

    2009-10-01

    A novel rickettsia was detected in Ixodes tasmani ticks collected from Tasmanian devils. A total of 55% were positive for the citrate synthase gene by quantitative PCR. According to current criteria for rickettsia speciation, this new rickettsia qualifies as Candidatus Rickettsia tasmanensis, named after the location of its detection.

  9. Phylogenetic diversity of the Rickettsiae.

    PubMed

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

    1989-08-01

    Small subunit rRNA sequences have been determined for representative strains of six species of the family Rickettsiaceae: Rickettsia rickettsii, Rickettsia prowazekii, Rickettsia typhi, Coxiella burnetii, Ehrlichia risticii, and Wolbachia persica. The relationships among these sequences and those of other eubacteria show that all members of the family Rickettsiaceae belong to the so-called purple bacterial phylum. The three representatives of the genus Rickettsia form a tight monophyletic cluster within the alpha subdivision of the purple bacteria. E. risticii also belongs to the alpha subdivision and shows a distant yet specific relationship to the genus Rickettsia. However, the family as a whole is not monophyletic, in that C. burnetii and W. persica are members of the gamma subdivision. The former appears to show a specific, but rather distant, relationship to the genus Legionella.

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

    PubMed Central

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

    2014-01-01

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

  11. A molecular survey of Rickettsia felis in fleas from cats and dogs in Sicily (Southern Italy).

    PubMed

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

    2014-01-01

    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.

  12. Genetic classification of "Rickettsia heilongjiangii" and "Rickettsia hulinii," two Chinese spotted fever group rickettsiae.

    PubMed

    Zhang, J Z; Fan, M Y; Wu, Y M; Fournier, P E; Roux, V; Raoult, D

    2000-09-01

    To determine the phylogenetic position of two new rickettsial strains isolated from ticks in China, 16S ribosomal DNA, gltA, and ompA (apart from the tandem repeat units) genes were amplified by PCR and sequenced. The phylogenetic relationships between these strains and other rickettsiae were inferred from the comparison of sequences of the three genes by the parsimony, neighbor-joining, and maximum-likelihood methods. The results demonstrated that the 054 strain, a rickettsia pathogenic in humans, and the HL-93 strain were related and clustered together with Rickettsia japonica. Significant statistical bootstrap values (100 and 92%) supported the nodes in this cluster. Based on previous genotypic and antigenic data and the phylogenetic analysis presented here, the 054 and HL-93 strains should be considered as new species, and we formally propose that they be named "Rickettsia heilongjiangii" and "Rickettsia hulinii," respectively.

  13. The emerging diversity of Rickettsia

    PubMed Central

    Perlman, Steve J; Hunter, Martha S; Zchori-Fein, Einat

    2006-01-01

    The best-known members of the bacterial genus Rickettsia are associates of blood-feeding arthropods that are pathogenic when transmitted to vertebrates. These species include the agents of acute human disease such as typhus and Rocky Mountain spotted fever. However, many other Rickettsia have been uncovered in recent surveys of bacteria associated with arthropods and other invertebrates; the hosts of these bacteria have no relationship with vertebrates. It is therefore perhaps more appropriate to consider Rickettsia as symbionts that are transmitted vertically in invertebrates, and secondarily as pathogens of vertebrates. In this review, we highlight the emerging diversity of Rickettsia species that are not associated with vertebrate pathogenicity. Phylogenetic analysis suggests multiple transitions between symbionts that are transmitted strictly vertically and those that exhibit mixed (horizontal and vertical) transmission. Rickettsia may thus be an excellent model system in which to study the evolution of transmission pathways. We also focus on the emergence of Rickettsia as a diverse reproductive manipulator of arthropods, similar to the closely related Wolbachia, including strains associated with male-killing, parthenogenesis, and effects on fertility. We emphasize some outstanding questions and potential research directions, and suggest ways in which the study of non-pathogenic Rickettsia can advance our understanding of their disease-causing relatives. PMID:16901827

  14. Pathogenic rickettsiae as bioterrorism agents.

    PubMed

    Azad, Abdu F

    2007-07-15

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

  15. Ecology of rickettsia in South America.

    PubMed

    Labruna, Marcelo B

    2009-05-01

    Until the year 2000, only three Rickettsia species were known in South America: (i) Rickettsia rickettsii, transmitted by the ticks Amblyomma cajennense, and Amblyomma aureolatum, reported in Colombia, Argentina, and Brazil, where it is the etiological agent of Rocky Mountain spotted fever; (ii) Rickettsia prowazekii, transmitted by body lice and causing epidemic typhus in highland areas, mainly in Peru; (iii) Rickettsia typhi, transmitted by fleas and causing endemic typhus in many countries. During this new century, at least seven other rickettsiae were reported in South America: Rickettsia felis infecting fleas and the tick-associated agents Rickettsia parkeri, Rickettsia massiliae, Candidatus"Rickettsia amblyommii,"Rickettsia bellii, Rickettsia rhipicephali, and Candidatus"Rickettsia andeanae." Among these other rickettsiae, only R. felis, R. parkeri, and R. massiliae are currently recognized as human pathogens. R. rickettsii is a rare agent in nature, infecting < or =1% individuals in a few tick populations. Contrastingly, R. parkeri, Candidatus"R. amblyommii," R. rhipicephali, and R. bellii are usually found infecting 10 to 100% individuals in different tick populations. Despite rickettsiae being transmitted transovarially through tick generations, low infection rates for R. rickettsii are possibly related to pathogenic effect of R. rickettsii for ticks, as shown for A. aureolatum under laboratory conditions. This scenario implies that R. rickettsii needs amplifier vertebrate hosts for its perpetuation in nature, in order to create new lines of infected ticks (horizontal transmission). In Brazil, capybaras and opossums are the most probable amplifier hosts for R. rickettsii, among A. cajennense ticks, and small rodents for A. aureolatum.

  16. Immunoproteomic profiling of Rickettsia parkeri and Rickettsia amblyommii.

    PubMed

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

    2015-09-01

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

  17. Detection of Rickettsia helvetica in ticks collected from European hedgehogs (Erinaceus europaeus, Linnaeus, 1758).

    PubMed

    Speck, Stephanie; Perseke, Lea; Petney, Trevor; Skuballa, Jasmin; Pfäffle, Miriam; Taraschewski, Horst; Bunnell, Toni; Essbauer, Sandra; Dobler, Gerhard

    2013-04-01

    The role of wild mammals in the dissemination and maintenance of Rickettsia in nature is still under investigation. European hedgehogs (Erinaceus europaeus) are often heavily infested by tick and flea species that are known to harbor and transmit different Rickettsia spp. We investigated ixodid ticks sampled from European hedgehogs for the presence of Rickettsia. A total of 471 Ixodes ricinus and 755 I. hexagonus were collected from 26 German and 7 British European hedgehogs. These were tested by a genus-specific real-time PCR assay targeting the citrate synthase gene (gltA). The rickettsia minimum infection rate was 11.7% with an increase detected with each parasitic tick stage. No significant difference in Rickettsia prevalence in the 2 Ixodes species was detected. Using sequencing of partial ompB, Rickettsia helvetica was the only species identified. More than half of the hedgehogs carried Rickettsia-positive ticks. In addition, tissue samples from 2/5 hedgehogs (where tissue DNA was available) were PCR-positive. These results show that European hedgehogs are exposed to R. helvetica via infected ticks and might be involved in the natural transmission cycle of this Rickettsia species.

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

    PubMed Central

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

    2011-01-01

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

  19. Rickettsia parkeri Rickettsiosis, Argentina.

    PubMed

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

    2011-07-01

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

  20. Rickettsia parkeri Rickettsiosis, Argentina

    PubMed Central

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

    2011-01-01

    Rickettsia parkeri, a recently identified cause of spotted fever rickettsiosis in the United States, has been found in Amblyomma triste ticks in several countries of South America, including Argentina, where it is believed to cause disease in humans. We describe the clinical and epidemiologic characteristics of 2 patients in Argentina with confirmed R. parkeri infection and 7 additional patients with suspected R. parkeri rickettsiosis identified at 1 hospital during 2004–2009. The frequency and character of clinical signs and symptoms among these 9 patients closely resembled those described for patients in the United States (presence of an inoculation eschar, maculopapular rash often associated with pustules or vesicles, infrequent gastrointestinal manifestations, and relatively benign clinical course). Many R. parkeri infections in South America are likely to be misdiagnosed as other infectious diseases, including Rocky Mountain spotted fever, dengue, or leptospirosis. PMID:21762568

  1. Prevalence of spotted fever group Rickettsia species detected in ticks in La Rioja, Spain.

    PubMed

    Oteo, J A; Portillo, A; Santibáñez, S; Pérez-Martínez, L; Blanco, J R; Jiménez, S; Ibarra, V; Pérez-Palacios, A; Sanz, M

    2006-10-01

    Our objective was to learn the prevalence of spotted fever group (SFG) Rickettsia detected in ticks in La Rioja, in the north of Spain. From 2001 to 2005, 496 ticks representing 7 tick species were analysed at the Hospital de La Rioja. Ticks were removed from humans with or without rickettsial syndrome (n = 59) or collected from mammals (n = 371) or from vegetation by dragging (n = 66). The presence of SFG Rickettsia in these ticks was investigated by semi-nested PCR (ompA gene) and sequencing. A phylogenetic tree using Clustal method (neighbor-joining) was constructed with these data. Only 3 of 170 Hyalomma marginatum ticks carried SFG Rickettsia. Sequencing analysis demonstrated the presence of Rickettsia aeschlimannii (1.8%). Furthermore, Rickettsia massiliae and BAR29 were found in 3 of 120 Rhipicephalus sanguineus specimens (2.5%). In contrast, 81 of 83 tested Dermacentor marginatus ticks were PCR-positive (97%). Rickettsia slovaca (40.6%) and Rickettsia sp. strains RpA4, DnS14, DnS28 and JL-02 (59.3%) were found within this tick species. No SFG Rickettsia was detected using ompA primers when Ixodes ricinus, Rhipicephalus bursa, Rhipicephalus turanicus, Rhipicephalus eversti eversti, Hyalomma detritum scupense and Rhipicephalus sp. were analyzed. We detected 17.5% of ticks associated with different SFG Rickettsia: R. aeschlimannii, R. massiliae, BAR29, R. slovaca and Rickettsia sp. strains RpA4, DnS14, DnS28 and JL-02. Their presence has to be taken into account since most of them have been recognized as human pathogens.

  2. Rickettsiae in Gulf Coast Ticks, Arkansas, USA

    PubMed Central

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

    2010-01-01

    To determine the cause of spotted fever cases in the southern United States, we screened Gulf Coast ticks (Amblyomma maculatum) collected in Arkansas for rickettsiae. Of the screened ticks, 30% had PCR amplicons consistent with Rickettsia parkeri or Candidatus Rickettsia amblyommii. PMID:20409375

  3. Rickettsiae and rickettsial diseases

    PubMed Central

    Brezina, R.; Murray, E. S.; Tarizzo, M. L.; Bögel, K.

    1973-01-01

    This paper summarizes present knowledge on rickettsiae and rickettsial diseases, and on their epidemiological characteristics, control, and public health significance. There are many natural foci of rickettsial diseases, from where the disease may spread to other areas in the world under changing socioeconomic conditions. Because of rapid long-distance travel, sporadic cases of serious rickettsial diseases may today appear far from endemic areas where the infection occurred. Even in endemic areas the disease may be misdiagnosed and deaths may occur as a result of inadequate treatment. Rapid treatment of rickettsial infections (preferably with tetracyclines) is therefore most important. Epidemic louse-borne typhus, though no longer subject to the International Health Regulations, remains one of the diseases in the WHO epidemiological surveillance programme. This disease continues to be a major cause of morbidity and mortality in some parts of Africa and it is present also in parts of the Americas and of Asia. Scrub typhus remains a continuing and serious public health problem in areas of South-East Asia and in the Western Pacific. The annual number of reported cases of Rocky Mountain spotted fever in the USA showed an increase during the last two decades, which may be due to improved recognition as well as to increased outdoor activities and migration of people from the city centres to the suburbs. Related forms of tick-borne typhus occur in South America, the Mediterranean region, Africa, South-East Asia, the Far East, and the Western Pacific. Increasing in number, though still sporadic, are reports of serious illness from chronic Q fever infection in many parts of the world. PMID:4547297

  4. Laboratory maintenance of Rickettsia rickettsii.

    PubMed

    Ammerman, Nicole C; Beier-Sexton, Magda; Azad, Abdu F

    2008-11-01

    This unit includes protocols for the laboratory maintenance of the obligate intracellular bacterium Rickettsia rickettsii, including propagation in mammalian cell cultures, as well as isolation, counting, and storage procedures. Regulations for working with R. rickettsii in biosafety level 3 containment are also discussed.

  5. Rickettsia felis in Fleas, Germany

    PubMed Central

    Just, Frank Thomas; Silaghi, Cornelia; Pradel, Ingrid; Passos, Lygia Maria Friche; Lengauer, Heidi; Hellmann, Klaus; Pfister, Kurt

    2008-01-01

    Among 310 fleas collected from dogs and cats in Germany, Rickettsia felis was detected in all specimens (34) of Archaeopsylla erinacei (hedgehog flea) and in 9% (24/226) of Ctenocephalides felis felis (cat flea). R. helvetica was detected in 1 Ceratophyllus gallinae (hen flea). PMID:18680660

  6. Human Infection with Rickettsia honei, Thailand

    DTIC Science & Technology

    2005-09-01

    1475 Rickettsia Genus of gram-negative, rod-shaped or coccoid bacteria that are transmitted by lice, fleas, ticks and mites. Named after American...Human Infection with Rickettsia honei, Thailand Ju Jiang,* Vichai Sangkasuwan,† Kriangkrai Lerdthusnee,‡ Suchitra Sukwit,† Thippawan Chuenchitra...ettsial genes used for multilocus sequence typing were 100% identical with those deposited with GenBank for Rickettsia honei TT-118. The original Thai

  7. Genome Sequence of Rickettsia bellii Illuminates the Role of Amoebae in Gene Exchanges between Intracellular Pathogens

    PubMed Central

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

    2006-01-01

    The recently sequenced Rickettsia felis genome revealed an unexpected plasmid carrying several genes usually associated with DNA transfer, suggesting that ancestral rickettsiae might have been endowed with a conjugation apparatus. Here we present the genome sequence of Rickettsia bellii, the earliest diverging species of known rickettsiae. The 1,552,076 base pair–long chromosome does not exhibit the colinearity observed between other rickettsia genomes, and encodes a complete set of putative conjugal DNA transfer genes most similar to homologues found in Protochlamydia amoebophila UWE25, an obligate symbiont of amoebae. The genome exhibits many other genes highly similar to homologues in intracellular bacteria of amoebae. We sought and observed sex pili-like cell surface appendages for R. bellii. We also found that R. bellii very efficiently multiplies in the nucleus of eukaryotic cells and survives in the phagocytic amoeba, Acanthamoeba polyphaga. These results suggest that amoeba-like ancestral protozoa could have served as a genetic “melting pot” where the ancestors of rickettsiae and other bacteria promiscuously exchanged genes, eventually leading to their adaptation to the intracellular lifestyle within eukaryotic cells. PMID:16703114

  8. Secretome of obligate intracellular Rickettsia

    PubMed Central

    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

  9. Evolution and diversity of Rickettsia bacteria

    PubMed Central

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

    2009-01-01

    Background Rickettsia are intracellular symbionts of eukaryotes that are best known for infecting and causing serious diseases in humans and other mammals. All known vertebrate-associated Rickettsia are vectored by arthropods as part of their life-cycle, and many other Rickettsia are found exclusively in arthropods with no known secondary host. However, little is known about the biology of these latter strains. Here, we have identified 20 new strains of Rickettsia from arthropods, and constructed a multi-gene phylogeny of the entire genus which includes these new strains. Results We show that Rickettsia are primarily arthropod-associated bacteria, and identify several novel groups within the genus. Rickettsia do not co-speciate with their hosts but host shifts most often occur between related arthropods. Rickettsia have evolved adaptations including transmission through vertebrates and killing males in some arthropod hosts. We uncovered one case of horizontal gene transfer among Rickettsia, where a strain is a chimera from two distantly related groups, but multi-gene analysis indicates that different parts of the genome tend to share the same phylogeny. Conclusion Approximately 150 million years ago, Rickettsia split into two main clades, one of which primarily infects arthropods, and the other infects a diverse range of protists, other eukaryotes and arthropods. There was then a rapid radiation about 50 million years ago, which coincided with the evolution of life history adaptations in a few branches of the phylogeny. Even though Rickettsia are thought to be primarily transmitted vertically, host associations are short lived with frequent switching to new host lineages. Recombination throughout the genus is generally uncommon, although there is evidence of horizontal gene transfer. A better understanding of the evolution of Rickettsia will help in the future to elucidate the mechanisms of pathogenicity, transmission and virulence. PMID:19187530

  10. Rickettsia parkeri in Amblyomma triste from Uruguay

    PubMed Central

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

    2004-01-01

    Our goal was to detect whether spotted fever group Rickettsia are found in the suspected vector of rickettsioses, Amblyomma triste, in Uruguay. Rickettsia parkeri was detected in A. triste, which suggests that this species could be considered a pathogenic agent responsible for human rickettsioses in Uruguay. PMID:15496258

  11. Integrated morphological and molecular identification of cat fleas (Ctenocephalides felis) and dog fleas (Ctenocephalides canis) vectoring Rickettsia felis in central Europe.

    PubMed

    Lawrence, Andrea L; Hii, Sze-Fui; Jirsová, Dagmar; Panáková, Lucia; Ionică, Angela M; Gilchrist, Katrina; Modrý, David; Mihalca, Andrei D; Webb, Cameron E; Traub, Rebecca J; Šlapeta, Jan

    2015-06-15

    Fleas of the genus Ctenocephalides are the most common ectoparasites infesting dogs and cats world-wide. The species Ctenocephalides felis and Ctenocephalides canis are competent vectors for zoonotic pathogens such as Rickettsia felis and Bartonella spp. Improved knowledge on the diversity and phylogenetics of fleas is important for understanding flea-borne pathogen transmission cycles. Fleas infesting privately owned dogs and cats from the Czech Republic (n=97) and Romania (n=66) were subjected to morphological and molecular identification and phylogenetic analysis. There were a total of 59 (60.82%) cat fleas (Ctenocephalides felis felis), 30 (30.93%) dog fleas (Ctenocephalides canis), 7 (7.22%) European chicken fleas (Ceratophyllus gallinae) and 1 (1.03%) northern rat flea (Nosopsyllus fasciatus) collected in the Czech Republic. Both C. canis and C. felis felis were identified in Romania. Mitochondrial DNA sequencing at the cox1 gene on a cohort of 40 fleas revealed the cosmopolitan C. felis felis clade represented by cox1 haplotype 1 is present in the Czech Republic. A new C. felis felis clade from both the Czech Republic and Romania is also reported. A high proportion of C. canis was observed from dogs and cats in the current study and phylogeny revealed that C. canis forms a sister clade to the oriental cat flea Ctenocephalides orientis (syn. C. felis orientis). Out of 33 fleas tested, representing C. felis felis, C. canis and Ce. gallinae, 7 (21.2%) were positive for R. felis using diagnostic real-time PCR targeting the gltA gene and a conventional PCR targeting the ompB gene. No samples tested positive for Bartonella spp. using a diagnostic real-time PCR assay targeting ssrA gene. This study confirms high genetic diversity of C. felis felis globally and serves as a foundation to understand the implication for zoonotic disease carriage and transmission by the flea genus Ctenocephalides.

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

    PubMed

    Carmichael, Jennifer R; Fuerst, Paul A

    2010-03-01

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

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

    PubMed Central

    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

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

    PubMed

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

    2012-12-01

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

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

    PubMed

    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.

  16. Isolation of the rickettsial agent genetically similar to Candidatus Rickettsia kotlanii, from Haemaphysalis megaspinosa in Japan.

    PubMed

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

    2014-09-01

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

  17. Frequency and Distribution of Rickettsiae, Borreliae, and Ehrlichiae Detected in Human-Parasitizing Ticks, Texas, USA

    PubMed Central

    Mitchell, Elizabeth A.; Williamson, Phillip C.; Billingsley, Peggy M.; Seals, Janel P.; Ferguson, Erin E.

    2016-01-01

    To describe the presence and distribution of tickborne bacteria and their vectors in Texas, USA, we screened ticks collected from humans during 2008–2014 for Rickettsia, Borrelia, and Ehrlichia spp. Thirteen tick species were identified, and 23% of ticks carried bacterial DNA from at least 1 of the 3 genera tested. PMID:26811941

  18. Rickettsia parkeri Rickettsiosis, Arizona, USA

    PubMed Central

    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.

    2016-01-01

    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. PMID:27089251

  19. Rickettsia parkeri Rickettsiosis, Arizona, USA.

    PubMed

    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.

  20. Absence of Rickettsia rickettsii and Occurrence of Other Spotted Fever Group Rickettsiae in Ticks from Tennessee

    PubMed Central

    Moncayo, Abelardo C.; Cohen, Sara B.; Fritzen, Charissa M.; Huang, Eileen; Yabsley, Michael J.; Freye, James D.; Dunlap, Brett G.; Huang, Junjun; Mead, Daniel G.; Jones, Timothy F.; Dunn, John R.

    2010-01-01

    Rocky Mountain spotted fever (RMSF) is the most common tick-borne illness in Tennessee. Little is known about the occurrence of R. rickettsii, the causative agent, in ticks in Tennessee. To better understand the prevalence and distribution of rickettsial agents in ticks, we tested 1,265 Amblyomma, Dermacentor, and Ixodes adult and nymphal ticks. Additionally, we tested 231 Amblyomma americanum larvae. Ticks were collected from 49 counties from humans, wild animals, domestic canines, and flannel drags. Spotted fever group rickettsiae (SFGR) DNA was detected by polymerase chain reaction (PCR) in 32% of adult and nymphal ticks. A total minimum infection rate of 85.63 was found in larval pools tested. Three rickettsial species, Rickettsia montana, Rickettsia amblyommii, and Rickettsia cooleyi were identified by molecular analysis. Rickettsia rickettsii was not detected. This study suggests that some RMSF cases reported in Tennessee may be caused by cross-reactivity with other SFGR antigenically related to R. rickettsii. PMID:20810834

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

    PubMed

    Moncayo, Abelardo C; Cohen, Sara B; Fritzen, Charissa M; Huang, Eileen; Yabsley, Michael J; Freye, James D; Dunlap, Brett G; Huang, Junjun; Mead, Daniel G; Jones, Timothy F; Dunn, John R

    2010-09-01

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

  2. In vitro and in vivo antibiotic susceptibilities of ELB rickettsiae.

    PubMed Central

    Radulovic, S; Higgins, J A; Jaworski, D C; Azad, A F

    1995-01-01

    The activities of doxycycline, rifampin, chloramphenicol, and erythromycin against ELB rickettsiae (Rickettsia azadi) were determined by dye uptake and plaque assays. Plaque formation in Vero cells was inhibited by 0.12 microgram of doxycycline per ml. The data presented demonstrate the susceptibility of ELB rickettsiae to commonly used antibiotics for the treatment of rickettsial diseases. PMID:8585746

  3. Rickettsia bellii infecting Amblyomma sabanerae ticks in El Salvador

    PubMed Central

    Barbieri, Amália R M; Romero, Luis; Labruna, Marcelo B

    2012-01-01

    Four Amblyomma sabanerae ticks collected from a turtle (Kinosternon sp.) in San Miguel, El Salvador, were found by molecular analysis to be infected by Rickettsia bellii. We provide the first report of Rickettsia bellii in Central America, and the first report of a Rickettsia species in El Salvador. PMID:23265378

  4. Rickettsia bellii infecting Amblyomma sabanerae ticks in El Salvador.

    PubMed

    Barbieri, Amália R M; Romero, Luis; Labruna, Marcelo B

    2012-07-01

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

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

    PubMed

    Kato, Cecilia Y; Chung, Ida H; Robinson, Lauren K; Austin, Amy L; Dasch, Gregory A; Massung, Robert F

    2013-01-01

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

  6. Infection by Rickettsia bellii and Candidatus "Rickettsia amblyommii" in Amblyomma neumanni ticks from Argentina.

    PubMed

    Labruna, Marcelo B; Pacheco, Richard C; Nava, Santiago; Brandão, Paulo E; Richtzenhain, Leonardo J; Guglielmone, Alberto A

    2007-07-01

    The tick species, Amblyomma neumanni (Acari: Ixodidae) is the most frequent tick parasitizing humans in northwestern Argentina. The present study evaluated the rickettsial infection among 55 A. neumanni adult free-living ticks collected in Dean Funes, Córdoba Province. Ticks were individually processed by the hemolymph test with Gimenez staining, isolation of rickettsia in Vero cell culture by the shell vial technique, and polymerase chain reaction (PCR) targeting the citrate synthase rickettsial gene. Through the shell vial technique, rickettsiae were successfully isolated and established in Vero cell culture from two ticks (ticks 4 and 13), which previously showed to contain Rickettsia-like organisms by the hemolymph test. These two Rickettsia isolates were designated as An4 and An13. Molecular characterization (partial DNA sequences of two to three rickettsial genes were determined) of these two isolates and phylogenetic analyses identified them as Rickettsia bellii (isolate An4) and Candidatus "Rickettsia amblyommii" (isolate An13). After testing all A. neumanni ticks by PCR, the prevalence of Candidatus R. amblyommii and R. bellii was 23.6% (13/55) and 3.6% (2/55), respectively. These two rickettsiae have been considered of unknown pathogenicity and appropriate studies to test their pathogenicity to humans or animals need to be conducted. This is the first report of Rickettsia in ticks from Argentina, and also in the species A. neumanni. The results reinforce previous findings that R. bellii (and probably Candidatus R. amblyommii) are widespread among some Neotropical Amblyomma species, suggesting that these ticks gained these bacterial agents from a common ancestor and/or by recent horizontal transmission of rickettsiae between ticks.

  7. 'Candidatus Rickettsia nicoyana': A novel Rickettsia species isolated from Ornithodoros knoxjonesi in Costa Rica.

    PubMed

    Moreira-Soto, Rolando D; Moreira-Soto, Andrés; Corrales-Aguilar, Eugenia; Calderón-Arguedas, Ólger; Troyo, Adriana

    2017-02-27

    Rickettsiae are intracellular bacteria commonly associated with hematophagous arthropods. Most of them have been described in hard ticks, but some have been found in soft ticks. Here we report the detection and isolation of a new Rickettsia from Ornithodoros knoxjonesi larvae collected from Balantiopteryx plicata (Emballonuridae) in Nicoya, Costa Rica. Two ticks were processed to detect Rickettsia spp. genes gltA, ompA, ompB, and htrA by PCR. Part of the macerate was also inoculated into Vero E6 and C6/36 cell lines, and cells were evaluated by Giménez stain, indirect immunofluorescence assay (IFA), and PCR. Both ticks were positive by PCR and rickettsial growth was successful in Vero E6 cells. Amplification and sequencing of near full length rrs, gltA, sca4 genes, and fragments of ompA and ompB showed that the Rickettsia sp. was different from described species. The highest homologies were with 'Candidatus Rickettsia wissemanii' and Rickettsia peacockii: 99.70% (1321/1325) with both sequences for rrs, 99.58% (1172/1177) and 99.76% (1246/1249) for gltA, 99.26% with both sequences (2948/2970 and 2957/2979) for sca4, 98.78% (485/491) and 98.39% (2069/2115) for ompA, and 98.58 (1453/1474) and 98.92% (1459/1475) for ompB; respectively. Bat blood, spleen, liver, and lung samples analyzed for Rickettsia detection were negative. Results demonstrate that the Rickettsia isolated from O. knoxjonesi is probably an undescribed species that belongs to the spotted fever group, for which 'Candidatus Rickettsia nicoyana' is proposed. Considering that B. plicata inhabits areas where contact with humans may occur and that human parasitism by Ornithodoros has been reported in the country, it will be important to continue with the characterization of this species and its pathogenic potential.

  8. Molecular detection of Rickettsia conorii and other zoonotic spotted fever group rickettsiae in ticks, Romania.

    PubMed

    Ionita, Mariana; Silaghi, Cornelia; Mitrea, Ioan Liviu; Edouard, Sophie; Parola, Philippe; Pfister, Kurt

    2016-02-01

    The diverse tick fauna as well as the abundance of tick populations in Romania represent potential risks for both human and animal health. Spotted fever group (SFG) rickettsiae are recognized as important agents of emerging human tick-borne diseases worldwide. However, the epidemiology of rickettsial diseases has been poorly investigated in Romania. In urban habitats, companion animals which are frequently exposed to tick infestation, play a role in maintenance of tick populations and as reservoirs of tick-borne pathogens. Therefore, the aim of the present study was to investigate the occurrence of SFG rickettsiae in ticks infesting dogs in a greater urban area in South-eastern Romania. Adult ixodid ticks (n=205), including Rhipicephalus sanguineus sensu lato (n=120), Dermacentor reticulatus (n=76) and Ixodes ricinus (n=9) were collected from naturally infested dogs and were screened for SFG rickettsiae using conventional PCR followed by sequencing. Additionally, ticks were screened for DNA of Babesia spp., Hepatozoon spp., Ehrlichia canis, and Anaplasma platys. Four zoonotic SFG rickettsiae were identified: Rickettsia raoultii (16%) and Rickettsia slovaca (3%) in D. reticulatus, Rickettsia monacensis (11%) in I. ricinus, and Rickettsia conorii (0.8%) in Rh. sanguineus s.l. Moreover, pathogens of veterinary importance, such as B. canis (21%) in D. reticulatus and E. canis (7.5%) in Rh. sanguineus s.l. were identified. The findings expand the knowledge on distribution of SFG rickettsiae as well as canine pathogens in Romania. Additionally, this is the first report describing the molecular detection of R. conorii in ticks from Romania.

  9. Genetic characterization of spotted fever group rickettsiae in questing ixodid ticks collected in Israel and environmental risk factors for their infection.

    PubMed

    Rose, Jessica; Nachum-Biala, Yaarit; Mumcuoglu, Kosta Y; Alkhamis, Moh A; Ben-Nun, Adi; Lensky, Itamar; Klement, Eyal; Nasereddin, Abedelmajeed; Abdeen, Ziad A; Harrus, Shimon

    2017-03-23

    This study aimed to genetically characterize spotted fever group rickettsiae (SFGR) in questing ixodid ticks from Israel and to identify risk factors associated with SFGR-positive ticks using molecular techniques and geographic information systems (GIS) analysis. 1039 ticks from the genus Rhipicephalus were collected during 2014. 109/1039 (10·49%) carried SFGR-DNA of either Rickettsia massiliae (95), 'Candidatus Rickettsia barbariae' (8) or Rickettsia conorii (6). Higher prevalence of SFGR was found in Rhipicephalus turanicus (18·00%) compared with Rhipicephalus sanguineus sensu lato (3·22%). Rickettsia massiliae was the most commonly detected species and the most widely disseminated throughout Israel (87·15% of all Rickettsia-positive ticks). GIS analysis revealed that Central and Northern coastal regions are at high risk for SFGR. The presence of ticks was significantly associated with normalized difference vegetation index and temperature variation over the course of the year. The presence of rickettsiae was significantly associated with brown type soils, higher land surface temperature and higher precipitation. The latter parameters may contribute to infection of the tick with SFGR. Health care professionals should be aware of the possible exposure of local communities and travellers to R. massillae. Molecular and geographical information can help professionals to identify areas that are susceptible to SFGR-infected ticks.

  10. Treatment of Rickettsia spp. infections: a review.

    PubMed

    Botelho-Nevers, Elisabeth; Socolovschi, Cristina; Raoult, Didier; Parola, Philippe

    2012-12-01

    Human rickettsioses caused by intracellular bacteria of the genus Rickettsia are distributed worldwide and are transmitted by arthropod vectors such as ticks, fleas, mites and lice. They have a wide range of manifestations from benign to life-threatening diseases. Mortality rates of up to 30% have been reported for some rickettsioses. Here, the authors will review in vitro and human studies of the various compounds that have been used for the treatment of Rickettsia spp. infections. The authors will also provide recommendations for the treatment of spotted fever and typhus group rickettsioses.

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

    PubMed Central

    2012-01-01

    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. PMID:22257726

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

    PubMed

    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 < 0.001). Significantly more ticks in nymphal stage were hosting Rickettsia spp. infection in spring, than in autumn. Four different genospecies were found: R. monacensis (29 ticks), R. helvetica (13), R. massiliae (3) and R. slovaca (2). The seasonal distribution of different Rickettsia spp. was heterogeneous; with most of the R. monacensis-infected ticks were found in spring, while more R. helvetica were found in autumn than spring. R. massiliae was found only in autumn and R. slovaca was found only in spring. This study has shown that 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

  13. Rickettsia rickettsii in Rhipicephalus ticks, Mexicali, Mexico.

    PubMed

    Eremeeva, Marina E; Zambrano, Maria L; Anaya, Luis; Beati, Lorenza; Karpathy, Sandor E; Santos-Silva, Maria Margarida; Salceda, Beatriz; MacBeth, Donald; Olguin, Hector; Dasch, Gregory A; Aranda, Celia Alpuche

    2011-03-01

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

  14. Rickettsia felis in Xenopsylla cheopis, Java, Indonesia

    PubMed Central

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

    2006-01-01

    Rickettsia typhi and R. felis, etiologic agents of murine typhus and fleaborne spotted fever, respectively, were detected in Oriental rat fleas (Xenopsylla cheopis) collected from rodents and shrews in Java, Indonesia. We describe the first evidence of R. felis in Indonesia and naturally occurring R. felis in Oriental rat fleas. PMID:16965716

  15. Rickettsia monacensis and human disease, Spain.

    PubMed

    Jado, Isabel; Oteo, José A; Aldámiz, Mikel; Gil, Horacio; Escudero, Raquel; Ibarra, Valvanera; Portu, Joseba; Portillo, Aranzazu; Lezaun, María J; García-Amil, Cristina; Rodríguez-Moreno, Isabel; Anda, Pedro

    2007-09-01

    We identified Rickettsia monacensis as a cause of acute tickborne rickettsiosis in 2 humans. Its pathogenic role was assessed by culture and detection of the organism in patients' blood samples. This finding increases the number of recognized human rickettsial pathogens and expands the known geographic distribution of Mediterranean spotted fever-like cases.

  16. Rickettsia Felis in Xenopsylla Cheopis, Java, Indonesia

    DTIC Science & Technology

    2006-08-01

    1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law , no person shall be subject to a penalty for...Clark P, Stenos J. Fenwick. Rickettsia felis in fleas, Western Australia. Emerg Infect Dis. 2006;12:841–3. 11. Richards AL, Soeatmandji DW, Widodo MA

  17. Rickettsia Species in African Anopheles Mosquitoes

    PubMed Central

    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

  18. Co-infection of Borrelia burgdorferi sensu lato and Rickettsia species in ticks and in an erythema migrans patient.

    PubMed

    Tijsse-Klasen, Ellen; Sprong, Hein; Pandak, Nenad

    2013-12-10

    Lyme borreliosis is the most prevalent tick-borne disease in Europe. Ixodes ricinus also carries other pathogenic bacteria, but corresponding human diseases are rarely reported. Here, we compared the exposure to Rickettsia helvetica and Rickettsia monacensis with that to Lyme borreliosis spirochetes. We assumed that their exposure corresponds to their infection rate in questing I. ricinus. Three Rickettsia species were detected in ticks with a total prevalence of 7.9%, of which the majority was R. helvetica (78%) and R. monacensis (21%). From the same geographic area, skin biopsies of erythema migrans patients were investigated for possible co-infections with Rickettsia spp.. Forty-seven out of 67 skin biopsies were PCR positive for Borrelia burgdorferi s.l. and one sample was positive for R. monacensis. The Borrelia genospecies from the R. monacensis positive patient was identified as Borrelia afzelii. The patient did not show any symptoms associated with rickettsiosis. Co-infections of I. ricinus with Rickettsia spp. and B. burgdorferi s.l. were as high as expected from the individual prevalence of both pathogens. Co-infection rate in erythema migrans patients corresponded well with tick infection rates. To our knowledge, this is the first reported co-infection of B. afzelii and R. monacensis.

  19. Rickettsia infection in dogs and Rickettsia parkeri in Amblyomma tigrinum ticks, Cochabamba Department, Bolivia.

    PubMed

    Tomassone, Laura; Conte, Valeria; Parrilla, Guillermo; De Meneghi, Daniele

    2010-12-01

    Only few published data are available on ticks and tick-borne zoonotic pathogens in Bolivia. To evaluate rickettsial seroprevalence and infection in dogs and ticks, during February-April 2007, we collected whole blood, sera, and ticks from dogs living in the rural, peri-urban, and urban areas of Cochabamba, Bolivia. Dog sera were subjected to enzyme-linked immunosorbent assay test to detect IgG antibodies against Rickettsia rickettsii and 68.2% of samples were found to be positive (n = 30; 95% confidence interval [CI]: 52.4-81.4). Blood samples and ticks were tested using polymerase chain reaction to detect spotted fever group (SFG) rickettsiae. One blood sample was positive for Rickettsia parkeri (2.3%; 95% CI: 0.06-12.3). Ticks were collected from 10 dogs and were identified as Amblyomma tigrinum (n = 44) and Rhipicephalus sanguineus (n = 1). All A. tigrinum ticks were collected from resident dogs from the rural areas of Cochabamba, whereas R. sanguineus was from a dog originating from Santa Cruz. Of 42 DNA samples extracted from ticks, 23 (54.8%; 95% CI: 38.7-70.1) were polymerase chain reaction positive for Rickettsia spp. Sequencing analysis identified 22 samples as R. parkeri and one as Rickettsia aeschlimannii. Positive ticks (all A. tigrinum) were collected from six dogs, all of which were seropositive. This is the first report of SFG rickettsiae in A. tigrinum, suggesting that this tick-like others species in the Amblyomma maculatum group--may play a role in the biological cycle of Ri. parkeri. The high infection prevalence of SFG rickettsiae in ticks and the even higher seroprevalence in dogs suggest an active circulation of agents of rickettsiosis in the study area, although there are no confirmed cases of infection in humans. Our study supports the use of canine serology as risk indicator for SF rickettsioses.

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

    PubMed

    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.

  1. Acquisition of polyamines by the obligate intracytoplasmic bacterium Rickettsia prowazekii.

    PubMed Central

    Speed, R R; Winkler, H H

    1990-01-01

    Both the polyamine content and the route of acquisition of polyamines by Rickettsia prowazekii, an obligate intracellular parasitic bacterium, were determined. The rickettsiae grew normally in an ornithine decarboxylase mutant of the Chinese hamster ovary (C55.7) cell line whether or not putrescine, which this host cell required in order to grow, was present. The rickettsiae contained approximately 6 mM putrescine, 5 mM spermidine, and 3 mM spermine when cultured in the presence or absence of putrescine. Neither the transport of putrescine and spermidine by the rickettsiae nor a measurable rickettsial ornithine decarboxylase activity could be demonstrated. However, we demonstrated the de novo synthesis of polyamines from arginine by the rickettsiae. Arginine decarboxylase activity (29 pmol of 14CO2 released per h per 10(8) rickettsiae) was measured in the rickettsiae growing within their host cell. A markedly lower level of this enzymatic activity was observed in cell extracts of R. prowazekii and could be completely inhibited with 1 mM difluoromethylarginine, an irreversible inhibitor of the enzyme. R. prowazekii failed to grow in C55.7 cells that had been cultured in the presence of 1 mM difluoromethylarginine. After rickettsiae were grown in C55.7 in the presence of labeled arginine, the specific activities of arginine in the host cell cytoplasm and polyamines in the rickettsiae were measured; these measurements indicated that 100% of the total polyamine content of R. prowazekii was derived from arginine. PMID:2120188

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

    PubMed

    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.

  3. Rickettsia felis, from culture to genome sequencing.

    PubMed

    Ogata, H; Robert, C; Audic, S; Robineau, S; Blanc, G; Fournier, P E; Renesto, P; Claverie, J M; Raoult, D

    2005-12-01

    Rickettsia felis has been recently cultured in XTC2 cells. This allows production of enough bacteria to create a genomic bank and to sequence it. The chromosome of R. felis is longer than that of previously sequenced rickettsiae and it possess 2 plasmids. Microscopically, this bacterium exhibits two forms of pili: one resembles a conjugative pilus and another forms hair-like projections that may play a role in pathogenicity. R. felis also exhibits several copies of ankyrin-repeat genes and tetratricopeptide encoding gene that are specifically linked to pathogenic host-associated bacteria. It also contains toxin-antitoxin system encoding genes that are extremely rare in intracellular bacteria and may be linked to plasmid maintenance.

  4. Isolation of Rickettsia rickettsii and Rickettsia bellii in cell culture from the tick Amblyomma aureolatum in Brazil.

    PubMed

    Pinter, Adriano; Labruna, Marcelo B

    2006-10-01

    Brazilian spotted fever (BSF) is a highly lethal disease caused by Rickettsia rickettsii. In the present study, rickettsial infection was evaluated in 669 Amblyomma aureolatum adult ticks collected from naturally infested dogs in Taiaçupeba, a BSF-endemic area in the state of São Paulo. Ten (1.49%) ticks were infected with Rickettsia bellii, and 6 (0.89%) ticks were infected with R. rickettsii. Both Rickettsia species were isolated and established in Vero cell cultures. The Rickettsia isolates were characterized by molecular analyses, sequencing fragments of different rickettsial genes. Our results suggest that A. aureolatum is an important vector of R. rickettsii in Brazil.

  5. Molecular detection of Rickettsia felis, Rickettsia typhi and two genotypes closely related to Bartonella elizabethae.

    PubMed

    De Sousa, Rita; Edouard-Fournier, Pierre; Santos-Silva, Margarida; Amaro, Fatima; Bacellar, Fatima; Raoult, Didier

    2006-10-01

    A total of 56 fleas were collected from mice, rats, and one hedgehog in national parks of mainland Portugal and the Madeira Island. All fleas were tested for the presence of bacteria of the genera Rickettsia and Bartonella using PCR assays. In fleas from mainland Portugal, we detected Rickettsia felis in one Archaeopsylla erinacei maura flea and in one Ctenophtalmus sp. In five Leptopsylla segnis fleas taken from rats in the Madeira Island, we identified Rickettsia typhi. In addition, in four fleas from the genera Ornithophaga and Stenoponia collect from mice and a rat in mainland Portugal, we detected the presence of two new Bartonella genotypes closely related to Bartonella elizabethae. Our findings emphasize the potential risk of flea-transmitted infections in mainland Portugal and the Madeira archipelago, and extend our knowledge of the potential flea vectors of human pathogens.

  6. Pathogenesis of Cell Injury by Rickettsia conorii

    DTIC Science & Technology

    1985-05-17

    as erzymes associated with tickbite in the pathogenesis of the tache noire. Experimental studies suggest that the dose of Inoculum of r~ckef~ert...and~ host cell mewbrane injury on rickottsial penetration Into and/or release fr~imuthe target cell. Experimental evidiewci indicates that host...uninfected chambers. Thus, in an experimental system In which rickettsiae injured infected host cell’s, we demonstrated no effect of putative toxin

  7. Pathogenesis of Cell Injury by Rickettsia conorii

    DTIC Science & Technology

    1986-11-26

    munfmoec ,IJckerttsa co’iorii. were !it’nonstrated!4. in 1.. ;¾Q’. rosuits in~dicamte that vascular in 1,rv by ricke’ttsiae is the ma jor les ion a~nd...ly)phocytes and macrophages; immunofluorescent Rickettsia conorti were demonstrated in 12. These results indicate that vascular injury by rickettsi’ae...affect man in a similar fashion with hematogenous spread and infec- tion of vascular endothelium producing increased vascular permeability and qascul

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

    PubMed Central

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

    2016-01-01

    Background 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. Methods 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. Results 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. Conclusions 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. PMID:27387337

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

    PubMed Central

    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 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. Results 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. Conclusions 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. PMID:24742108

  10. Plasmids and Rickettsial Evolution: Insight from Rickettsia felis

    PubMed Central

    Gillespie, Joseph J.; Beier, Magda S.; Rahman, M. Sayeedur; Ammerman, Nicole C.; Shallom, Joshua M.; Purkayastha, Anjan; Sobral, Bruno S.; Azad, Abdu F.

    2007-01-01

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

  11. Importation of exotic ticks and tick-borne spotted fever group rickettsiae into the United States by migrating songbirds.

    PubMed

    Mukherjee, Nabanita; Beati, Lorenza; Sellers, Michael; Burton, Laquita; Adamson, Steven; Robbins, Richard G; Moore, Frank; Karim, Shahid

    2014-03-01

    Birds are capable of carrying ticks and, consequently, tick-transmitted microorganisms over long distances and across geographical barriers such as oceans and deserts. Ticks are hosts for several species of spotted fever group rickettsiae (SFGR), which can be transmitted to vertebrates during blood meals. In this study, the prevalence of this group of rickettsiae was examined in ticks infesting migratory songbirds by using polymerase chain reaction (PCR). During the 2009 and 2010 spring migration season, 2064 northward-migrating passerine songbirds were examined for ticks at Johnson Bayou, Louisiana. A total of 91 ticks was removed from 35 individual songbirds for tick species identification and spotted fever group rickettsia detection. Ticks were identified as Haemaphysalis juxtakochi (n=38, 42%), Amblyomma longirostre (n=22, 24%), Amblyomma nodosum (n=17, 19%), Amblyomma calcaratum (n=11, 12%), Amblyomma maculatum (n=2, 2%), and Haemaphysalis leporispalustris (n=1, 1%) by comparing their 12S rDNA gene sequence to homologous sequences in GenBank. Most of the identified ticks were exotic species originating outside of the United States. The phylogenetic analysis of the 71 ompA gene sequences of the rickettsial strains detected in the ticks revealed the occurrence of 6 distinct rickettsial genotypes. Two genotypes (corresponding to a total of 28 samples) were included in the Candidatus Rickettsia amblyommii clade (less than 1% divergence), 2 of them (corresponding to a total of 14 samples) clustered with Rickettsia sp. "Argentina" with less than 0.2% sequence divergence, and 2 of them (corresponding to a total of 27 samples), although closely related to the R. parkeri-R. africae lineage (2.50-3.41% divergence), exhibited sufficient genetic divergence from its members to possibly constitute a new rickettsial genotype. Overall, there does not seem to be a specific relationship between exotic tick species, the rickettsiae they harbor, or the reservoir competence of the

  12. Importation of exotic ticks and tick-borne spotted fever group rickettsiae into the United States by migrating songbirds

    PubMed Central

    Mukherjee, Nabanita; Beati, Lorenza; Sellers, Michael; Burton, Laquita; Adamson, Steven; Robbins, Richard G.; Moore, Frank; Karim, Shahid

    2013-01-01

    Birds are capable of carrying ticks and, consequently, tick-transmitted microorganisms over long distances and across geographical barriers such as oceans and deserts. Ticks are hosts for several species of spotted fever group rickettsiae (SFGR), which can be transmitted to vertebrates during blood meals. In this study, the prevalence of this group of rickettsiae was examined in ticks infesting migratory songbirds by using polymerase chain reaction (PCR). During the 2009 and 2010 spring migration season, 2064 northward-migrating passerine songbirds were examined for ticks at Johnson Bayou, Louisiana. A total of 91 ticks was removed from 35 individual songbirds for tick species identification and spotted fever group rickettsia detection. Ticks were identified as Haemaphysalis juxtakochi (n=38, 42%), Amblyomma longirostre (n=22, 24%), Amblyomma nodosum (n=17, 19%), Amblyomma calcaratum (n=11, 12%), Amblyomma maculatum (n=2, 2%), and Haemaphysalis leporispalustris (n=1, 1%) by comparing their 12S rDNA gene sequence to homologous sequences in GenBank. Most of the identified ticks were exotic species originating outside of the United States. The phylogenetic analysis of the 71 ompA gene sequences of the rickettsial strains detected in the ticks revealed the occurrence of 6 distinct rickettsial genotypes. Two genotypes (corresponding to a total of 28 samples) were included in the Candidatus Rickettsia amblyommii clade (less than 1% divergence), 2 of them (corresponding to a total of 14 samples) clustered with Rickettsia sp. “Argentina” with less than 0.2% sequence divergence, and 2 of them (corresponding to a total of 27 samples), although closely related to the R. parkeri–R. africae lineage (2.50–3.41% divergence), exhibited sufficient genetic divergence from its members to possibly constitute a new rickettsial genotype. Overall, there does not seem to be a specific relationship between exotic tick species, the rickettsiae they harbor, or the reservoir

  13. Molecular Detection of Rickettsia amblyommii in Amblyomma americanum Parasitizing Humans

    DTIC Science & Technology

    2010-01-01

    Rocky Mountain spotted fever [RMSF...diseases in North Carolina: is "Rickettsia amblyommii" a possible cause of rickettsiosis reported as Rocky Mountain spotted fever ? Vector Borne Zoonot...HN, et al. Rickettsia parkeri rickettsiosis and its clinical distinction from Rocky Mountain spotted fever . Clin Infect Dis 2008; 47:1188-

  14. High Seroprevalence for Typhus Group Rickettsiae, Southwestern Tanzania

    PubMed Central

    Dill, Tatjana; Dobler, Gerhard; Saathoff, Elmar; Clowes, Petra; Kroidl, Inge; Ntinginya, Elias; Machibya, Harun; Maboko, Leonard; Löscher, Thomas; Hoelscher, Michael

    2013-01-01

    Rickettsioses caused by typhus group rickettsiae have been reported in various African regions. We conducted a cross-sectional survey of 1,227 participants from 9 different sites in the Mbeya region, Tanzania; overall seroprevalence of typhus group rickettsiae was 9.3%. Risk factors identified in multivariable analysis included low vegetation density and highway proximity. PMID:23347529

  15. 21 CFR 866.3500 - Rickettsia serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Rickettsia serological reagents. 866.3500 Section 866.3500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3500 Rickettsia...

  16. 21 CFR 866.3500 - Rickettsia serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rickettsia serological reagents. 866.3500 Section 866.3500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3500 Rickettsia...

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

    PubMed

    Sumrandee, Chalao; Hirunkanokpun, Supanee; Doornbos, Kathryn; Kitthawee, Sangvorn; Baimai, Visut; Grubhoffer, Libor; Trinachartvanit, Wachareeporn; Ahantarig, Arunee

    2014-10-01

    Some reptile ticks are potential vectors of pathogens such as spotted fever group (SFG) rickettsiae. Here, we report for the first time in detail the molecular evidence, DNA sequences and phylogenetic studies, for the presence of Rickettsia spp. in Amblyomma ticks (Amblyomma helvolum and Amblyomma varanense) from snakes in Thailand. A total of 24 tick samples was collected from 4 snake species and identified. A phylogenetic analysis inferred from the partial sequences of the gltA gene indicated that the Rickettsia spp. from 2 Amblyomma helvolum and 1 Amblyomma varanense belong to the same group as the SFG rickettsiae, which are closely related to Rickettsia raoultii strains. In contrast, there was 1 Rickettsia sp. from Amblyomma helvolum grouped into the same clade with other SFG rickettsiae (Rickettsia tamurae, Rickettsia monacensis, and a Rickettsia endosymbiont of Amblyomma dubitatum from Brazil). However, another Rickettsia sp. from Amblyomma varanense was closely related to Rickettsia bellii and Rickettsia sp. strain RDa420 from Thailand. In addition, from phylogenetic results based on the 16S rRNA gene and a concatenated tree of the 3 genes (gltA, ompA, and ompB), we found what may be a novel SFG rickettsia species closely related to Rickettsia raoultii (from both Amblyomma varanense and Amblyomma helvolum). In conclusion, our findings are the first report on the presence of novel SFG rickettsiae in 2 snake tick species, Amblyomma varanense and Amblyomma helvolum in Thailand and in south-eastern Asia.

  18. Exotic Rickettsiae in Ixodes ricinus: fact or artifact?

    PubMed Central

    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 and presenting these findings as new or potentially pathogenic Rickettsiae should be done with caution: a recent report suggested presence of a known human pathogen, R. australis, in questing I. ricinus ticks in Europe. A refined analysis of these results revealed that R. helvetica was most likely to be misinterpreted as R. australis. Evidence in the literature is accumulating that rickettsial DNA sequences found in tick lysates can also be derived from other sources than viable, pathogenic Rickettsiae. For example, from endosymbionts, environmental contamination or even horizontal gene transfer. PMID:20569494

  19. Experimental infection with Rickettsia rickettsii in an Amblyomma dubitatum tick colony, naturally infected by Rickettsia bellii.

    PubMed

    Sakai, Renata K; Costa, Francisco B; Ueno, Tatiana E H; Ramirez, Diego G; Soares, João F; Fonseca, Adivaldo H; Labruna, Marcelo B; Barros-Battesti, Darci M

    2014-10-01

    Amblyomma dubitatum engorged females, naturally infected by Rickettsia bellii, were used to establish a laboratory colony. Larvae, nymphs, and adults were exposed to two strains of Rickettsia rickettsii by feeding on needle-inoculated guinea pigs, and thereafter reared on uninfected guinea pigs. After acquisition feeding, engorged larvae and nymphs molted to nymphs and adults, respectively, which were shown to be infected (confirming transstadial perpetuation), and were able to transmit both strains of R. rickettsii to uninfected animals, as demonstrated by clinical, serological, and molecular analyses. However, the larval, nymphal, and adult stages of A. dubitatum showed to be only partially susceptible to R. rickettsii infection, since in all cases, only part of the ticks became infected by this agent, after being exposed to rickettsemic animals. While transovarial transmission of R. rickettsii was inefficient in the A. dubitatum engorged females of the present study, 100% of these females passed R. bellii transovarially. Because it has been reported that a primary infection by a Rickettsia species would preclude transovarial transmission of a second Rickettsia species, it is likely that the ineffectiveness of A. dubitatum to perpetuate R. rickettsii by transovarial transmission was related to its primary infection by R. bellii; however, it could also be related to unknown factors inherent to A. dubitatum. The relevance of A. dubitatum as a natural vector of R. rickettsii to humans or animals is discussed.

  20. Molecular detection of Rickettsia bellii and Rickettsia sp. strain Colombianensi in ticks from Cordoba, Colombia.

    PubMed

    Miranda, Jorge; Mattar, Salim

    2014-03-01

    The purpose of this study was to provide molecular evidence of Rickettsia spp. in ticks collected from 2 sites of Cordoba. From May to June 2009, 1069 Amblyomma cajennense ticks were removed from 40 capybaras (Hydrochoerus hydrochaeris) in a rural locality of Monteria. Furthermore, 458 Amblyomma sp. larvae and 20 Amblyomma sp. nymphs were collected in a rural locality of Los Cordobas (Cordoba) by drag sampling on vegetation (n=1547). Ticks were grouped into pools and tested for rickettsial infection by real-time PCR targeting the rickettsial gene gltA. Subsequently, PCR targeting for gltA, ompA, ompB, and 16S rRNA, sequencing, and phylogenetic analyses were undertaken. Rickettsial DNA was detected in 10 (4.6%) out of 214 pools of ticks by RT-PCR. Five (33%) of free-living Amblyomma sp. larval pools were positive, as well as 5 (2.6%) pools from A. cajennense. Only the gltA gene was amplified from 5 pools of free-living larvae. The nucleotide sequences were 100% identical to R. bellii by BLAST. Only one pool from A. cajennense was positive for gltA, ompA, ompB, and 16S rRNA. The partial nucleotide sequences of these genes were 100% identical to nucleotide sequences of the same genes of a new proposed species Candidatus Rickettsia sp. strain Colombianensi. This is the first report of R. bellii in ticks in Colombia and the second report of detection of Candidatus Rickettsia sp. strain Colombianensi. These Rickettsia species are still considered of unknown pathogenicity. Further studies are needed to characterize the ecological and potential pathogenic role of these 2 Rickettsia species found in Cordoba.

  1. Detection of Rickettsia rickettsii and Rickettsia sp. in blood clots in 24 patients from different municipalities of the State of Sao Paulo, Brazil.

    PubMed

    Gehrke, Flávia Sousa; Mendes do Nascimento, Elvira Maria; Rodrigues de Souza, Eliana; Colombo, Silvia; Jacintho da Silva, Luiz; Schumaker, Teresinha Tizu Sato

    2006-10-01

    The authors detected Rickettsia genus organisms using shell vial and polymerase chain reaction (PCR)/sequencing analysis in blood clots in patients suspected of having Brazilian spotted fever (BSF). DNA was detected using PCR with three sets of primers to access the gltA, ompA, and ompB genes. Sequence analysis was carried out using an automatic sequencer with Bioedit software. Seventy-five percent of the culture samples were positive and all samples amplified rickettsial gene fragments. To date, 46% of the samples have been sequenced.

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

    PubMed Central

    Dzul-Rosado, Karla; Lugo-Caballero, Cesar; Tello-Martin, Raul; López-Avila, Karina; Zavala-Castro, Jorge

    2017-01-01

    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. PMID:28652984

  3. Detection of Rickettsia rickettsii, Rickettsia parkeri, and Rickettsia akari in skin biopsy specimens using a multiplex real-time polymerase chain reaction assay.

    PubMed

    Denison, Amy M; Amin, Bijal D; Nicholson, William L; Paddock, Christopher D

    2014-09-01

    Rickettsia rickettsii, Rickettsia parkeri, and Rickettsia akari are the most common causes of spotted fever group rickettsioses indigenous to the United States. Infected patients characteristically present with a maculopapular rash, often accompanied by an inoculation eschar. Skin biopsy specimens are often obtained from these lesions for diagnostic evaluation. However, a species-specific diagnosis is achieved infrequently from pathologic specimens because immunohistochemical stains do not differentiate among the causative agents of spotted fever group rickettsiae, and existing polymerase chain reaction (PCR) assays generally target large gene segments that may be difficult or impossible to obtain from formalin-fixed tissues. This work describes the development and evaluation of a multiplex real-time PCR assay for the detection of these 3 Rickettsia species from formalin-fixed, paraffin-embedded (FFPE) skin biopsy specimens. The multiplex PCR assay was specific at discriminating each species from FFPE controls of unrelated bacterial, viral, protozoan, and fungal pathogens that cause skin lesions, as well as other closely related spotted fever group Rickettsia species. This multiplex real-time PCR demonstrates greater sensitivity than nested PCR assays in FFPE tissues and provides an effective method to specifically identify cases of Rocky Mountain spotted fever, rickettsialpox, and R. parkeri rickettsiosis by using skin biopsy specimens. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  4. The realities of biodefense vaccines against Rickettsia

    PubMed Central

    Walker, David H.

    2010-01-01

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

  5. Tick-borne rickettsiae in Guinea and Liberia.

    PubMed

    Mediannikov, Oleg; Diatta, Georges; Zolia, Yah; Balde, Mamadou Cellou; Kohar, Henry; Trape, Jean-François; Raoult, Didier

    2012-02-01

    While the high seroprevalence for the rickettsiae that cause spotted fevers and the multiple pathogenic rickettsiae is known, the data on the distribution of rickettsial diseases in Africa are often incomplete. We collected ticks from domestic or wild animals (generally a source of bushmeat) that were in contact with humans in 2 neighboring countries of tropical West Africa, Guinea and Liberia. In total, 382 ticks representing 6 species were collected in Liberia and 655 ticks representing 7 species were collected in Guinea. We found rickettsiae in 9 different species of ticks from both countries. Rickettsia africae was found in 93-100% of Amblyomma variegatum, in 14-93% of Rhipicephalus (B.) geigyi, Rh. (B.) annulatus, and Rh. (B.) decoloratus, and in several Hyalomma marginatum rufipes and Haemaphysalis paraleachi. A genetic variant of R. africae was found in Amblyomma compressum. R. massiliae was found in 10/61 (16%) of Rh. senegalensis ticks and in 2% of Haemaphysalis paraleachi ticks collected from dogs. We identified a new rickettsia in one of 44 (2%) Ixodes muniensis collected from a dog in Liberia. As this rickettsia is not yet isolated, we propose the provisional name "Candidatus Rickettsia liberiensis" (for the West African country where the host tick was collected).

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

    PubMed

    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.

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

    PubMed

    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.

  8. A common origin of rickettsiae and certain plant pathogens.

    PubMed

    Weisburg, W G; Woese, C R; Dobson, M E; Weiss, E

    1985-11-01

    On the basis of ribosomal RNA sequence comparisons, the rickettsia Rochalimaea quintana has been found to be a member of subgroup 2 of the alpha subdivision of the so-called purple bacteria, which is one of about ten major eubacterial divisions. Within subgroup alpha-2, R. quintana is specifically related to the agrobacteria and rhizobacteria, organisms that also have close associations with eukaryotic cells. This genealogical grouping of the rickettsiae with certain plant pathogens and intracellular symbionts suggests a possible evolution of the rickettsiae from plant-associated bacteria.

  9. Proteomic Analysis of Rickettsia parkeri Strain Portsmouth▿

    PubMed Central

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

    2009-01-01

    Rickettsia parkeri, a recently recognized pathogen of human, is one of several Rickettsia spp. in the United States that causes a spotted fever rickettsiosis. To gain insights into its biology and pathogenesis, we applied the proteomics approach to establish a two-dimensional gel proteome reference map and combined this technique with cell surface biotinylation to identify surface-exposed proteins of a low-passage isolate of R. parkeri obtained from a patient. We identified 91 proteins by matrix-assisted laser desorption ionization-tandem time of flight mass spectrometry. Of these, 28 were characterized as surface proteins, including virulence-related proteins (e.g., outer membrane protein A [OmpA], OmpB, β-peptide, and RickA). Two-dimensional immunoblotting with serum from the R. parkeri-infected index patient was utilized to identify the immunoreactive proteins as potential targets for diagnosis and vaccine development. In addition to the known rickettsial antigens, OmpA and OmpB, we identified translation initiation factor 2, cell division protein FtsZ, and cysteinyl-tRNA synthetase as immunoreactive proteins. The proteome map with corresponding cell surface protein analysis and antigen detection will facilitate a better understanding of the mechanisms of rickettsial pathogenesis. PMID:19797064

  10. In vitro isolation from Amblyomma ovale (Acari: Ixodidae) and ecological aspects of the Atlantic rainforest Rickettsia, the causative agent of a novel spotted fever rickettsiosis in Brazil.

    PubMed

    Szabó, M P J; Nieri-Bastos, F A; Spolidorio, M G; Martins, T F; Barbieri, A M; Labruna, M B

    2013-05-01

    Recently, a novel human rickettsiosis, namely Atlantic rainforest spotted fever, was described in Brazil. We herein report results of a survey led around the index case in an Atlantic rainforest reserve in Peruibe municipality, southeastern Brazil. A Rickettsia parkeri-like agent (Rickettsia sp. Atlantic rainforest genotype) and Ricketsia bellii were isolated from adult Amblyomma ovale ticks collected from dogs. Molecular evidence of infection with strain Atlantic rainforest was obtained for 30 (12.9%) of 232 A. ovale adult ticks collected from dogs. As many as 88.6% of the 35 examined dogs had anti-Rickettsia antibodies, with endpoint titres at their highest to R. parkeri. High correlation among antibody titres in dogs, A. ovale infestations, and access to rainforest was observed. Amblyomma ovale subadults were found predominantly on a rodent species (Euryoryzomys russatus). From 17 E. russatus tested, 6 (35.3%) displayed anti-Rickettsia antibodies, with endpoint titres highest to R. parkeri. It is concluded that Atlantic rainforest genotype circulates in this Atlantic rainforest area at relatively high levels. Dogs get infected when bitten by A. ovale ticks in the forest, and carry infected ticks to households. The role of E. russatus as an amplifier host of Rickettsia to A. ovale ticks deserves investigation.

  11. Rickettsia felis in Ctenocephalides felis from Guatemala and Costa Rica

    PubMed Central

    Troyo, Adriana; Álvarez, Danilo; Taylor, Lizeth; Abdalla, Gabriela; Calderón-Arguedas, Ólger; Zambrano, Maria L.; Dasch, Gregory A.; Lindblade, Kim; Hun, Laya; Eremeeva, Marina E.; Estévez, Alejandra

    2012-01-01

    Rickettsia felis is an emerging human pathogen associated primarily with the cat flea Ctenocephalides felis. In this study, we investigated the presence of Rickettsia felis in C. felis from Guatemala and Costa Rica. Ctenocephalides felis were collected directly from dogs and cats, and analyzed by polymerase chain reaction for Rickettsia-specific fragments of 17-kDa protein, OmpA, and citrate synthase genes. Rickettsia DNA was detected in 64% (55 of 86) and 58% (47 of 81) of flea pools in Guatemala and Costa Rica, respectively. Sequencing of gltA fragments identified R. felis genotype URRWXCal2 in samples from both countries, and genotype Rf2125 in Costa Rica. This is the first report of R. felis in Guatemala and of genotype Rf2125 in Costa Rica. The extensive presence of this pathogen in countries of Central America stresses the need for increased awareness and diagnosis. PMID:22665618

  12. Rickettsia felis in Ctenocephalides felis from Guatemala and Costa Rica.

    PubMed

    Troyo, Adriana; Álvarez, Danilo; Taylor, Lizeth; Abdalla, Gabriela; Calderón-Arguedas, Ólger; Zambrano, Maria L; Dasch, Gregory A; Lindblade, Kim; Hun, Laya; Eremeeva, Marina E; Estévez, Alejandra

    2012-06-01

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

  13. Genetic identification of rickettsiae isolated from ticks in Japan.

    PubMed

    Fournier, Pierre-Edouard; Fujita, Hiromi; Takada, Nobuhiro; Raoult, Didier

    2002-06-01

    Following the description in Japan of Japanese spotted fever, caused by Rickettsia japonica, a search for the vector of this disease led to the isolation of several rickettsiae from various tick species. Sixty-three rickettsial isolates were obtained from six different tick species, and six type strains were described by PCR and monoclonal antibody testing. We identified these six strains by amplification and sequencing of the genes encoding 16S rRNA and citrate synthase. We confirmed that the isolates from Dermacentor taiwanensis and Haemaphysalis flava ticks were R. japonica isolates. In Ixodes ovatus, Ixodes persulcatus, and Ixodes monospinosus, we identified a Rickettsia identical or closely related to Rickettsia helvetica, a species that is pathogenic for humans and that to date has only been found in Europe. Finally, we identified a new genotype of unknown pathogenicity, genotype AT, that was isolated from Amblyomma testudinarium ticks and that is closely related to a Slovakian genotype obtained from Ixodes ricinus ticks.

  14. Zoonotic surveillance for rickettsiae in domestic animals in Kenya.

    PubMed

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

    2013-06-01

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

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

    PubMed Central

    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

  16. Ticks and rickettsiae from wildlife in Belize, Central America.

    PubMed

    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

  17. Human Infections by Multiple Spotted Fever Group Rickettsiae in Tennessee.

    PubMed

    Delisle, Josie; Mendell, Nicole L; Stull-Lane, Annica; Bloch, Karen C; Bouyer, Donald H; Moncayo, Abelardo C

    2016-06-01

    Rocky Mountain spotted fever is the most common tick-borne disease in Tennessee. However, Rickettsia rickettsii has rarely been isolated from endemic ticks, suggesting rickettsioses may be caused by other species. A total of 56 human serum samples that were serologically positive for exposure to Rickettsia were obtained from commercial laboratories in 2010 and 2011. In addition, 20 paired sera from patients with encephalitis and positive Rickettsia serology were obtained from the Tennessee Unexplained Encephalitis Surveillance (TUES) study. Using an immunofluorescence assay, reactivity of the sera to R. rickettsii, Rickettsia montanensis, Rickettsia parkeri, and Rickettsia amblyommii was tested, and a comparison of endpoint titers was used to determine the probable antigen that stimulated the antibody response. Cross-absorption was conducted for 94.8% (N = 91) of the samples due to serologic cross-reactivity. Of the commercial laboratory samples, 55.4% (N = 31) had specific reactivity to R. amblyommii and 44.6% (N = 25) were indeterminate. Of the paired TUES samples, 20% (N = 4) had specific reactivity to R. amblyommii, 5% (N = 1) to R. montanensis, and 5% (N = 1) to R. parkeri Patients with specific reactivity to R. amblyommii experienced fever (75%), headache (68%) and myalgia (58%). Rash (36%) and thrombocytopenia (40%) were less common. To our knowledge, this is the first time R. amblyommii has been reported as a possible causative agent of rickettsioses in Tennessee. © The American Society of Tropical Medicine and Hygiene.

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

    PubMed

    McQuiston, Jennifer H; Zemtsova, Galina; Perniciaro, Jamie; Hutson, Mark; Singleton, Joseph; Nicholson, William L; Levin, Michael L

    2012-12-01

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

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

    PubMed

    Eremeeva, Marina E; Dasch, Gregory A; Silverman, David J

    2003-12-01

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

  20. Carrying Loom

    ERIC Educational Resources Information Center

    Lazaron, Edna

    1976-01-01

    Whenever a young student wanted to weave, his loom was at school or at home. He solved the problem by designing a portable loom which he is able to carry with his school books and can even use on the school bus. (Author/RK)

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

    PubMed

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

    2014-10-01

    Ixodes boliviensis is a tick of carnivores that is common on domestic dogs. The only Rickettsia that has been detected previously in this species is 'Candidatus Rickettsia andeanae'. We report the detection of an undescribed Rickettsia sp., named strain IbR/CRC, in I. boliviensis collected from dogs in Costa Rica. Analyses of gltA, ompA, and htrA partial sequences place Rickettsia sp. strain IbR/CRC in the group of R. monacensis, also close to an endosymbiont of Ixodes scapularis and other undescribed rickettsiae. It was not possible to isolate Rickettsia sp. strain IbR/CRC in Vero E6 or C6/36 cell lines. Isolation and further characterization of Rickettsia sp. strain IbR/CRC and the other undescribed rickettsiae are required to determine their taxonomic status and pathogenic potential. Copyright © 2014 Elsevier GmbH. All rights reserved.

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

    DTIC Science & Technology

    2004-11-15

    DNA Microarray Analysis of Human Monocytes Early Response Genes upon Infection with Rickettsia rickettsii Chien-Chung Chao Rickettsiae Diseases...TITLE AND SUBTITLE DNA Microarray Analysis of Human Monocytes Early Response Genes upon Infection with Rickettsia rickettsii 5a. CONTRACT NUMBER 5b...ANSI Std Z39-18 Rickettsiae • Gram negative coccobacillary bacteria • Obligate intracellular organisms • Arthropod-borne • Cause febrile diseases (mild

  3. Detection of Rickettsiae in Arthropod Vectors by DNA Amplification Using the Polymerase Chain Reaction

    DTIC Science & Technology

    1990-01-01

    Rickettsia rickettsii 17-kDa-antigen gene sequence. 6- we synthe- sized two oligonucleotides 20 bases in length that are complementary to two aThis study was...ntigen’detection, indirect immunofluorescence, rickettsiae , artht’opod vectorE Rikettsia rickettsii , 17-KDa-antigen gene selqti’ence, typhus group rickettsiae ...stored in tubes contain- ing 0.5 ml brain heart infusion broth (BHI) at -70°C. Rickettsia rickettsii -infected Dermacentor variabilis was kindly provided

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

    PubMed

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

    2008-06-01

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

  5. Human Infection with Novel Spotted Fever Group Rickettsia Genotype, China, 2015

    PubMed Central

    Li, Hao; Cui, Xiao-Ming; Cui, Ning; Yang, Zhen-Dong; Hu, Jian-Gong; Fan, Ya-Di; Fan, Xue-Juan; Zhang, Lan; Zhang, Pan-He

    2016-01-01

    Only 4 species of spotted fever group rickettsiae have been detected in humans in China. However, phylogenetic analysis of samples from 5 ill patients in China indicated infection with a novel spotted fever group Rickettsia, designated Rickettsia sp. XY99. Clinical signs resembled those of severe fever with thrombocytopenia syndrome. PMID:27869588

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

    PubMed

    Balayeva, N M; Eremeeva, M E; Raoult, D

    1994-12-01

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

  7. Diversity of rickettsiae in a rural community in northern California.

    PubMed

    Stephenson, Nicole; Blaney, Alexandra; Clifford, Deana; Gabriel, Mourad; Wengert, Greta; Foley, Patrick; Brown, Richard N; Higley, Mark; Buckenberger-Mantovani, Sarah; Foley, Janet

    2017-02-27

    Far northern California forests are highly biodiverse in wildlife reservoirs and arthropod vectors that may propagate rickettsial pathogens in nature. The proximity of small rural communities to these forests puts people and domestic animals at risk of vector-borne infection due to spillover from wildlife. The current study was conducted to document exposure to rickettsial pathogens in people and domestic animals in a rural community, and identify which rickettsiae are present in sylvatic and peri-domestic environments near this community. Blood samples from people, domestic animals (dogs, cats, and horses) and wild carnivores were tested for Rickettsia spp. antibodies and DNA (people and domestic animals only) by serology and real time (RT)-PCR, respectively. Ectoparasites were collected from dogs, wild carnivores and from vegetation by flagging, and tested for Rickettsia spp. DNA by RT-PCR. DNA sequencing of the rickettsial 17kDa protein gene or the ompA gene was used for species identification. Despite a seroprevalence of 3% in people, 42% in dogs, 79% in cats, 33% in gray foxes, and 83% in bobcats, RT-PCR on blood was consistently negative, likely because the sensitivity of this test is low, as Rickettsia spp. do not often circulate in high numbers in the blood. Rickettsia spp. DNA was found in four flea species collected from bobcats and Ctenocephalides felis collected from domestic dogs. All amplicons sequenced from fleas were R. felis. Ixodes pacificus collected by flagging were commonly infected with a Rickettsia sp. endosymbiont. Rickettsia rhipicephali DNA was found in Dermacentor variabilis from dogs, black bears, a gray fox, and a D. occidentalis collected by flagging. Dermacentor variabilis from dogs and black bears also contained R. montanensis DNA. Multiple Rickettsia spp. (including species with zoonotic and pathogenic potential) were found among human biting arthropod vectors of both wild and domestic carnivores and on flags. Knowledge of the

  8. Extremely Low Genomic Diversity of Rickettsia japonica Distributed in Japan

    PubMed Central

    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

    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. PMID:28057731

  9. Molecular Evidence of Different Rickettsia Species in Villeta, Colombia.

    PubMed

    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.

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

    PubMed

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

    1989-10-01

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

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

    PubMed

    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.

  12. THE ANTIGENIC RELATIONSHIP BETWEEN PROTEUS X-19 AND TYPHUS RICKETTSIA

    PubMed Central

    Castaneda, M. Ruiz

    1934-01-01

    A soluble specific substance was isolated from Mexican typhus Rickettsia which gave, with Proteus X-19 antiserum and typhus human serum, the same precipitation reactions as the polysaccharides extracted from B. proteus OX-19. The soluble specific substance extracted from Rickettsia and Proteus OX-19 is likely to be of a polysaccharide nature owing to the strong Molisch reactions obtained with such extracts, the heat stability and the negative protein reactions (biuret). Since, however, it still contains 7 per cent nitrogen, this is not certain. In the antigenic composition of both Proteus X-19 and typhus Rickettsia there is a common soluble specific factor which is responsible for the Weil-Felix reaction. PMID:19870282

  13. Evidence of Rickettsia prowazekii infections in the United States.

    PubMed

    McDade, J E; Shepard, C C; Redus, M A; Newhouse, V F; Smith, J D

    1980-03-01

    From January 1976 through January 1979 serum specimens from 1,575 individuals were received at the Center for Disease Control and tested for antibodies to rickettsiae. Of these, sera from eight persons gave serological results indicative of recent infections with epidemic typhus rickettsiae (Rickettsia prowazekii). Five of the persons were from Georgia, and one each was from Tennessee, Pennsylvania and Massachusetts. The illnesses occurred during the winter, chiefly in persons living in a rural environment. The clinical picture was compatible with louse-borne epidemic typhus. There was no apparent contact with human body or head lice, and no cases occurred in patient contacts, indicating that infection was not associated with the classic man-louse-man cycle of epidemic typhus. Two of the eight patients had contact with flying squirrels suggesting that they became infected from this known extrahuman reservoir of R. prowazekii.

  14. Mapping of Monoclonal Antibody Binding Sites on CNBr Fragments of the S- Layer Protein Antigens of Rickettsia Typhi and Rickettsia Prowazekii

    DTIC Science & Technology

    1992-01-01

    SUBJECT TERMS (Continue on reverse if necessary and identify by block number) FIEL GROP SS.GRUP typhus rickettsiae ; pathogenic bacteria ; immunity; DNA...terminal glycine (Streuli and are scattered over the much of both the R. prowa:ekii Griffin, 1987). Since rickettsiae grow in the cytoplasm and R. rickettsii ...surface-exposed protein of Ricketsia and protective efficacy in guinea pigs. In Rickettsiae and rickettsii . Mol. Microbiol. 3, 1579-1586. Rickettsial

  15. Molecular detection and characterization of spotted fever group rickettsiae in ticks from Central Italy.

    PubMed

    Scarpulla, M; Barlozzari, G; Marcario, A; Salvato, L; Blanda, V; De Liberato, C; D'Agostini, C; Torina, A; Macrì, G

    2016-07-01

    The aim of this study was to investigate the presence of rickettsial pathogens in ticks from Central Italy. A total of 113 ticks hailed from Latium and Tuscany regions were identified and tested by PCR to detect gltA, ompA, ompB genes of Rickettsia. Positive amplicons were sequenced and identified at species level. Ticks were analyzed individually or in pools. The percentage of positivity for SFG rickettsiae was 12.4%, expressed as minimum infection rate (MIR) assuming that one tick was positive in each positive pool. Rickettsia aeschlimannii was detected in Hyalomma marginatum, Rickettsia monacensis in Ixodes ricinus and Rickettsia massiliae and Rickettsia conorii in Rhipicephalus sanguineus sensu lato. These findings confirm the circulation of pathogenic rickettsiae in Latium and Tuscany regions. To our knowledge this is the first report of R. massiliae in Latium region.

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

    PubMed Central

    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

  17. A Patient from Argentina Infected with Rickettsia massiliae

    PubMed Central

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

    2010-01-01

    The first confirmed case of Rickettsia massiliae infection in the New World (Buenos Aires, Argentina) is described. To date, only two cases of human infection had been reported in Europe. The patient, a woman, had a fever, a palpable purpuric rash on the upper and lower extremities, and a skin lesion (eschar) on the right leg compatible with tache noire. When interviewed, she reported having had contact with dog ticks. After treatment with doxycycline for 12 days, her symptoms resolved. Rickettsia massiliae infection was diagnosed by molecular-based detection of the microorganism in a biopsy specimen of the eschar. PMID:20348520

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

    PubMed

    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.

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

    PubMed

    Doornbos, Kathryn; Sumrandee, Chalao; Ruang-Areerate, Toon; Baimai, Visut; Trinachartvanit, Wachareeporn; Ahantarig, Arunee

    2013-01-01

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

  20. Small Regulatory RNAs of Rickettsia conorii

    PubMed Central

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

    2016-01-01

    Small regulatory RNAs comprise critically important modulators of gene expression in bacteria, yet very little is known about their prevalence and functions in Rickettsia species. R. conorii, the causative agent of Mediterranean spotted fever, is a tick-borne pathogen that primarily infects microvascular endothelium in humans. We have determined the transcriptional landscape of R. conorii during infection of Human Microvascular Endothelial Cells (HMECs) by strand-specific RNA sequencing to identify 4 riboswitches, 13 trans-acting (intergenic), and 22 cis-acting (antisense) small RNAs (termed ‘Rc_sR’s). Independent expression of four novel trans-acting sRNAs (Rc_sR31, Rc_sR33, Rc_sR35, and Rc_sR42) and known bacterial sRNAs (6S, RNaseP_bact_a, ffs, and α-tmRNA) was next confirmed by Northern hybridization. Comparative analysis during infection of HMECs vis-à-vis tick AAE2 cells revealed significantly higher expression of Rc_sR35 and Rc_sR42 in HMECs, whereas Rc_sR31 and Rc_sR33 were expressed at similar levels in both cell types. We further predicted a total of 502 genes involved in all important biological processes as potential targets of Rc_sRs and validated the interaction of Rc_sR42 with cydA (cytochrome d ubiquinol oxidase subunit I). Our findings constitute the first evidence of the existence of post-transcriptional riboregulatory mechanisms in R. conorii and interactions between a novel Rc_sR and its target mRNA. PMID:27834404

  1. Cat fleas (Ctenocephalides felis) from cats and dogs in New Zealand: Molecular characterisation, presence of Rickettsia felis and Bartonella clarridgeiae and comparison with Australia.

    PubMed

    Chandra, Shona; Forsyth, Maureen; Lawrence, Andrea L; Emery, David; Šlapeta, Jan

    2017-01-30

    The cat flea (Ctenocephalides felis) is the most common flea species parasitising both domestic cats and dogs globally. Fleas are known vectors of zoonotic pathogens such as vector borne Rickettsia and Bartonella. This study compared cat fleas from domestic cats and dogs in New Zealand's North and South Islands to Australian cat fleas, using the mitochondrial DNA (mtDNA) marker, cytochrome c oxidase subunit I and II (cox1, cox2). We assessed the prevalence of Rickettsia and Bartonella using genus specific multiplexed real-time PCR assays. Morphological identification confirmed that the cat flea (C. felis) is the most common flea in New Zealand. The examined fleas (n=43) at cox1 locus revealed six closely related C. felis haplotypes (inter-haplotype distance 1.1%) across New Zealand. The New Zealand C. felis haplotypes were identical or near identical with haplotypes from southern Australia demonstrating common dispersal of haplotype lineage across both the geographical (Tasman Sea) and climate scale. New Zealand cat fleas carried Rickettsia felis (5.3%) and Bartonella clarridgeiae (18.4%). To understand the capability of C. felis to vector zoonotic pathogens, we determined flea cox1 and cox2 haplotype diversity with the tandem multiplexed real-time PCR and sequencing for Bartonella and Rickettsia. This enabled us to demonstrate highly similar cat fleas on cat and dog populations across Australia and New Zealand. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Genomic comparison of virulent Rickettsia rickettsii Sheila Smith and avirulent Rickettsia rickettsii Iowa.

    PubMed

    Ellison, Damon W; Clark, Tina R; Sturdevant, Daniel E; Virtaneva, Kimmo; Porcella, Stephen F; Hackstadt, Ted

    2008-02-01

    Rickettsia rickettsii is an obligate intracellular pathogen that is the causative agent of Rocky Mountain spotted fever. To identify genes involved in the virulence of R. rickettsii, the genome of an avirulent strain, R. rickettsii Iowa, was sequenced and compared to the genome of the virulent strain R. rickettsii Sheila Smith. R. rickettsii Iowa is avirulent in a guinea pig model of infection and displays altered plaque morphology with decreased lysis of infected host cells. Comparison of the two genomes revealed that R. rickettsii Iowa and R. rickettsii Sheila Smith share a high degree of sequence identity. A whole-genome alignment comparing R. rickettsii Iowa to R. rickettsii Sheila Smith revealed a total of 143 deletions for the two strains. A subsequent single-nucleotide polymorphism (SNP) analysis comparing Iowa to Sheila Smith revealed 492 SNPs for the two genomes. One of the deletions in R. rickettsii Iowa truncates rompA, encoding a major surface antigen (rickettsial outer membrane protein A [rOmpA]) and member of the autotransporter family, 660 bp from the start of translation. Immunoblotting and immunofluorescence confirmed the absence of rOmpA from R. rickettsii Iowa. In addition, R. rickettsii Iowa is defective in the processing of rOmpB, an autotransporter and also a major surface antigen of spotted fever group rickettsiae. Disruption of rompA and the defect in rOmpB processing are most likely factors that contribute to the avirulence of R. rickettsii Iowa. Genomic differences between the two strains do not significantly alter gene expression as analysis of microarrays revealed only four differences in gene expression between R. rickettsii Iowa and R. rickettsii strain R. Although R. rickettsii Iowa does not cause apparent disease, infection of guinea pigs with this strain confers protection against subsequent challenge with the virulent strain R. rickettsii Sheila Smith.

  3. Proposal to create subspecies of Rickettsia sibirica and an emended description of Rickettsia sibirica.

    PubMed

    Fournier, Pierre-Edouard; Zhu, Yong; Yu, Xuejie; Raoult, Didier

    2006-10-01

    The Rickettsia sibirica species is composed of isolates that are genotypically close but can be classified within two distinct serotypes, that is, R. sibirica sensu stricto and R. sibirica mongolitimonae (incorrectly named R. mongolotimonae). We investigated the possibility of classifying rickettsiae closely related to R. sibirica as R. sibirica subspecies, as proposed by the ad hoc Committee on Reconciliation of Approaches to Bacterial Systematics. For this, we first estimated the genotypic variability by using multilocus sequence typing (MLST), including the sequencing of five genes, and multispacer typing (MST) using three intergenic spacers, of five isolates and three tick amplicons of R. sibirica sensu stricto and six isolates of R. sibirica mongolotimonae. Then, we selected a representative of each MLST genotype and used mouse serotyping to estimate their degree of taxonomic relatedness. Among the 14 isolates or tick amplicons studied, 2 MLST genotypes were identified: (i) the R. sibirica sensu stricto type; and (ii) the R. sibirica mongolitimonae type. Representatives of the two MLST types were classified within three MST types and into two serotypes. Therefore, as isolates within the R. sibirica species are genotypically homogeneous but show MST genotypic, serotypic, and epidemio-clinical dissimilarities, we propose to modify the nomenclature of the R. sibirica species through the creation of subspecies. We propose the names R. sibirica subsp. sibirica subsp. nov. (type strain = 2-4-6, ATCC VR-541(T)), and R. sibirica subsp. mongolitimonae subsp. nov. (type strain = HA-91, ATCC VR-1526(T)). The description of R. sibirica is emended to accommodate the two subspecies.

  4. Gulf Coast Ticks (Amblyomma maculatum) and Rickettsia parkeri, United States

    PubMed Central

    Sumner, John W.; Durden, Lance A.; Goddard, Jerome; Stromdahl, Ellen Y.; Clark, Kerry L.; Reeves, Will K.

    2007-01-01

    Geographic distribution of Rickettsia parkeri in its US tick vector, Amblyomma maculatum, was evaluated by PCR. R. parkeri was detected in ticks from Florida, Georgia, Kentucky, Mississippi, Oklahoma, and South Carolina, which suggests that A. maculatum may be responsible for additional cases of R. parkeri rickettsiosis throughout much of its US range. PMID:17553257

  5. Human Infection with Rickettsia sibirica mongolitimonae, Spain, 2007–2011

    PubMed Central

    Jado, Isabel; Padilla, Sergio; Masiá, Mar; Anda, Pedro; Gutiérrez, Félix

    2013-01-01

    Human infection with Rickettsia sibirica mongolitimonae was initially reported in 1996, and reports of a total of 18 cases have been published. We describe 6 additional cases that occurred in the Mediterranean coast region of Spain during 2007–2011. Clinicians should consider this infection in patients who have traveled to this area. PMID:23343524

  6. 21 CFR 866.3500 - Rickettsia serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Rickettsia serological reagents. 866.3500 Section 866.3500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES..., some of these reagents consist of rickettsial antisera conjugated with a fluorescent...

  7. 21 CFR 866.3500 - Rickettsia serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Rickettsia serological reagents. 866.3500 Section 866.3500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES..., some of these reagents consist of rickettsial antisera conjugated with a fluorescent...

  8. 21 CFR 866.3500 - Rickettsia serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Rickettsia serological reagents. 866.3500 Section 866.3500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES..., some of these reagents consist of rickettsial antisera conjugated with a fluorescent...

  9. Amblyomma imitator ticks as vectors of Rickettsia rickettsii, Mexico.

    PubMed

    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; Bouyer, Donald H

    2010-08-01

    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.

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

    PubMed

    Breitschwerdt, Edward B; Hegarty, Barbara C; Maggi, Ricardo G; Lantos, Paul M; Aslett, Denise M; Bradley, Julie M

    2011-05-01

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

  11. Extremely low genomic diversity of Rickettsia japonica distributed in Japan.

    PubMed

    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

    2017-01-04

    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 R. 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.

  12. Rickettsia parkeri in Amblyomma americanum Ticks, Tennessee and Georgia, USA

    PubMed Central

    Cohen, Sara B.; Yabsley, Michael J.; Garrison, Laurel E.; Freye, James D.; Dunlap, Brett G.; Dunn, John R.; Mead, Daniel G.; Jones, Timothy F.

    2009-01-01

    To determine the geographic distribution of the newly recognized human pathogen Rickettsia parkeri, we looked for this organism in ticks from Tennessee and Georgia, USA. Using PCR and sequence analysis, we identified R. parkeri in 2 Amblyomma americanum ticks. This rickettsiosis may be underdiagnosed in the eastern United States. PMID:19788817

  13. Rickettsia sibirica mongolitimonae Infection, France, 2010–2014

    PubMed Central

    Angelakis, Emmanouil; Richet, Herve

    2016-01-01

    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. PMID:27088367

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

    PubMed

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

    2016-04-21

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

  15. FINDING OF RICKETTSIA BURNETI IN HORSEFLIES TABANUS STAEGERI,

    DTIC Science & Technology

    The paper presents data on isolation of Rickettsia burneti from horseflies Tabanus staegeri in Kazakhstan. A short characteristic of rickettsial...is raised on the necessity of further complex study of the role of Mongolian and other horseflies in the epidemiology and epizootology of Q rickettsiosis. (Author)

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

    PubMed

    Kuo, C C; Huang, J L; Lin, T E; Wang, H C

    2012-09-01

    Rickettsia typhi and Rickettsia felis (Rickettsiales: Rickettsiaceae) are two rickettsiae principally transmitted by fleas, but the detection of either pathogen has rarely been attempted in Taiwan. Of 2048 small mammals trapped in eastern Taiwan, Apodemus agrarius Pallas (24.5%) and Mus caroli Bonhote (24.4%) (both: Rodentia: Muridae) were the most abundant, and M. caroli hosted the highest proportion of fleas (63.9% of 330 fleas). Two flea species were identified: Stivalius aporus Jordan and Rothschild (Siphonaptera: Stivaliidae), and Acropsylla episema Rothschild (Siphonaptera: Leptopsyllidae). Nested polymerase chain reaction targeting parts of the ompB and gltA genes showed six fleas to be positive for Rickettsia spp. (3.8% of 160 samples), which showed the greatest similarity to R. felis, Rickettsia japonica, Rickettsia conorii or Rickettsia sp. TwKM01. Rickettsia typhi was not detected in the fleas and Rickettsia co-infection did not occur. Both flea species were more abundant during months with lower temperatures and less rainfall, and flea abundance on M. caroli was not related to soil hardness, vegetative height, ground cover by litter or by understory layer, or the abundance of M. caroli. Our study reveals the potential circulation of R. felis and other rickettsiae in eastern Taiwan, necessitating further surveillance of rickettsial diseases in this region. This is especially important because many novel rickettsioses are emerging worldwide. © 2012 The Authors. Medical and Veterinary Entomology © 2012 The Royal Entomological Society.

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

    PubMed Central

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

    1986-01-01

    The DNA from flying squirrel-associated Rickettsia prowazekii was characterized by using a specific DNA fragment produced by digestion with the enzyme BamHI. The DNA fragment was cloned into a plasmid vector and used to readily distinguish between available human- and flying squirrel-associated R. prowazekii DNAs derived from crude cytoplasmic extracts. Images PMID:3009528

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

    PubMed

    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.

  19. Detection of “Candidatus Rickettsia sp. strain Argentina”and Rickettsia bellii in Amblyomma ticks (Acari: Ixodidae) from Northern Argentina

    PubMed Central

    Tomassone, L.; Nuñez, P.; Ceballos, L. A.; Gürtler, R. E.; Kitron, U.; Farber, M.

    2011-01-01

    Ixodid ticks were collected from vegetation and from humans, wild and domestic mammals in a rural area in the semi-arid Argentine Chaco in late spring 2006 to evaluate their potential role as vectors of Spotted Fever Group (SFG) rickettsiae. A total of 233 adult ticks, identified as Amblyomma parvum, Amblyomma tigrinum and Amblyomma pseudoconcolor, was examined for Rickettsia spp. We identified an SFG rickettsia of unknown pathogenicity, “Candidatus Rickettsia sp. strain Argentina”, in A. parvum and A. pseudoconcolor by PCR assays targeting gltA, ompA, ompB and 17-kDa outer membrane antigen rickettsial genes. Rickettsia bellii was detected in a host-seeking male of A. tigrinum. Amblyomma parvum is widespread in the study area and is a potential threat to human health. PMID:20186466

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

    PubMed

    Jiang, Ju; Stromdahl, Ellen Y; Richards, Allen L

    2012-03-01

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

  1. Coinfections of Rickettsia slovaca and Rickettsia helvetica with Borrelia lusitaniae in ticks collected in a Safari Park, Portugal.

    PubMed

    Milhano, Natacha; de Carvalho, Isabel Lopes; Alves, Ana Sofia; Arroube, Sofia; Soares, Jorge; Rodriguez, Pablo; Carolino, Manuela; Núncio, Maria Sofia; Piesman, Joseph; de Sousa, Rita

    2010-12-01

    Borrelia and Rickettsia bacteria are the most important tick-borne agents causing disease in Portugal. Identification and characterization of these circulating agents, mainly in recreational areas, is crucial for the development of preventive measures in response to the gradually increasing exposure of humans to tick vectors. A total of 677 questing ticks including Dermacentor marginatus, Rhipicephalus sanguineus, Ixodes ricinus, Hyalomma lusitanicum, H. marginatum, and Haemaphysalis punctata were collected in a Safari Park in Alentejo, Portugal, to investigate the prevalences of infection and characterize Borrelia and Rickettsia species. From a total of 371 ticks tested by PCR for Borrelia burgdorferi sensu lato (s.l.), of which 247 were tested for Rickettsia, an infection prevalence of 18.3% was found for B. lusitaniae and 55.1% for Rickettsia spp. Sequence analysis of positive amplicons identified the presence of B. lusitaniae (18.3%), R. monacensis strain IRS3 (51.7%), and R. helvetica (48.3%) in I. ricinus. R. slovaca (41.5%), R. raoultii (58.5%), and also B. lusitaniae (21%) were identified in D. marginatus ticks. One (5.9%) H. lusitanicum was infected with B. lusitaniae, and R. massiliae was found in one Rhipicephalus sanguineus. Coinfection was found in 7 (20%) I. ricinus and 34 (23.3%) D. marginatus ticks. We report, for the first time, simultaneous infection with R. helvetica and B. lusitaniae and also R. slovaca, the agent of TIBOLA/DEBONEL, with B. lusitaniae. Additionally, 6 isolates of B. lusitaniae were established, and isolates of Rickettsia were also obtained for the detected species using tick macerates cultured in mammalian and mosquito cell lines. This report describes the detection and isolation of tick-borne agents from a Portuguese Safari Park, highlighting the increased likelihood of infection with multiple agents to potential visitors or staff. Copyright © 2010 Elsevier GmbH. All rights reserved.

  2. High prevalence of spotted fever group rickettsiae in Amblyomma variegatum from Uganda and their identification using sizes of intergenic spacers.

    PubMed

    Nakao, Ryo; Qiu, Yongjin; Igarashi, Manabu; Magona, Joseph W; Zhou, Lijia; Ito, Kimihito; Sugimoto, Chihiro

    2013-12-01

    The spotted fever group (SFG) rickettsiae are obligate intracellular bacteria transmitted by ticks that cause several tick-borne rickettsioses in humans worldwide. This study was intended to determine the prevalence of SFG rickettsiae in Amblyomma variegatum from 7 districts across Uganda. In addition to sequencing of gltA and ompA genes, identification of Rickettsia species based on the sizes of highly variable intergenic spacers, namely, dksA-xerC, mppA-purC, and rpmE-tRNA(fMet) was carried out. Application of multiplex PCR for simultaneous amplification of 3 spacers combined with capillary electrophoresis separation allowed simple, accurate, and high-throughput fragment sizing with considerable time and cost savings. Rickettsia genus-specific real-time PCR detected 136 positives out of 140 samples, giving an overall prevalence of 97.1%. Most samples (n=113) had a size combination of 225, 195, and 341 bp for dksA-xerC, mppA-purC, and rpmE-tRNA(fMet), respectively, which was identical to that of R. africae, a causative agent of African tick bite fever. In addition, several samples had size variants in either dksA-xerC or rpmE-tRNA(fMet). Nonetheless, the partial sequences of gltA and ompA genes of samples of all size combinations showed the greatest similarity to R. africae (99.3-100% for gltA and 98.1-100% for ompA). Given these results, it is highly possible that the tested ticks were infected with R. africae or closely related species. This is a first report on molecular genetic detection of R. africae and its high endemicity in Uganda. Clinicians in this country should be aware of this pathogen as a cause of non-malarial febrile illness. This study provided a starting point for the development of Rickettsia species identification based on the sizes of intergenic spacers. The procedure is simple, rapid, and cost-effective to perform; hence it might be particularly well suited for preliminary species identification in epidemiological investigations. The results

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

    PubMed Central

    2013-01-01

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

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

    PubMed

    Tijsse-Klasen, Ellen; Hansford, Kayleigh M; Jahfari, Setareh; Phipps, Paul; Sprong, Hein; Medlock, Jolyon M

    2013-07-19

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

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

    PubMed

    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.

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

    PubMed Central

    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

  7. Dissemination of spotted fever rickettsia agents in Europe by migrating birds.

    PubMed

    Elfving, Karin; Olsen, Björn; Bergström, Sven; Waldenström, Jonas; Lundkvist, Ake; Sjöstedt, Anders; Mejlon, Hans; Nilsson, Kenneth

    2010-01-05

    Migratory birds are known to play a role as long-distance vectors for many microorganisms. To investigate whether this is true of rickettsial agents as well, we characterized tick infestation and gathered ticks from 13,260 migratory passerine birds in Sweden. A total of 1127 Ixodes spp. ticks were removed from these birds and the extracted DNA from 957 of them was available for analyses. The DNA was assayed for detection of Rickettsia spp. using real-time PCR, followed by DNA sequencing for species identification. Rickettsia spp. organisms were detected in 108 (11.3%) of the ticks. Rickettsia helvetica, a spotted fever rickettsia associated with human infections, was predominant among the PCR-positive samples. In 9 (0.8%) of the ticks, the partial sequences of 17kDa and ompB genes showed the greatest similarity to Rickettsia monacensis, an etiologic agent of Mediterranean spotted fever-like illness, previously described in southern Europe as well as to the Rickettsia sp.IrITA3 strain. For 15 (1.4%) of the ticks, the 17kDa, ompB, gltA and ompA genes showed the greatest similarity to Rickettsia sp. strain Davousti, Rickettsia japonica and Rickettsia heilongjiangensis, all closely phylogenetically related, the former previously found in Amblyomma tholloni ticks in Africa and previously not detected in Ixodes spp. ticks. The infestation prevalence of ticks infected with rickettsial organisms was four times higher among ground foraging birds than among other bird species, but the two groups were equally competent in transmitting Rickettsia species. The birds did not seem to serve as reservoir hosts for Rickettsia spp., but in one case it seems likely that the bird was rickettsiemic and that the ticks had acquired the bacteria from the blood of the bird. In conclusion, migratory passerine birds host epidemiologically important vector ticks and Rickettsia species and contribute to the geographic distribution of spotted fever rickettsial agents and their diseases.

  8. Rickettsia Phylogenomics: Unwinding the Intricacies of Obligate Intracellular Life

    PubMed Central

    Gillespie, Joseph J.; Williams, Kelly; Shukla, Maulik; Snyder, Eric E.; Nordberg, Eric K.; Ceraul, Shane M.; Dharmanolla, Chitti; Rainey, Daphne; Soneja, Jeetendra; Shallom, Joshua M.; Vishnubhat, Nataraj Dongre; Wattam, Rebecca; Purkayastha, Anjan; Czar, Michael; Crasta, Oswald; Setubal, Joao C.; Azad, Abdu F.; Sobral, Bruno S.

    2008-01-01

    Background Completed genome sequences are rapidly increasing for Rickettsia, obligate intracellular α-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 (∼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 distribution of 14354 predicted

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

    PubMed

    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.

  10. Molecular detection of the human pathogenic Rickettsia sp. strain Atlantic rainforest in Amblyomma dubitatum ticks from Argentina.

    PubMed

    Monje, Lucas D; Nava, Santiago; Eberhardt, Ayelen T; Correa, Ana I; Guglielmone, Alberto A; Beldomenico, Pablo M

    2015-02-01

    To date, three tick-borne pathogenic Rickettsia species have been reported in different regions of Argentina, namely, R. rickettsii, R. parkeri, and R. massiliae. However, there are no reports available for the presence of tick-borne pathogens from the northeastern region of Argentina. This study evaluated the infection with Rickettsia species of Amblyomma dubitatum ticks collected from vegetation and feeding from capybaras (Hydrochoerus hydrochaeris) in northeastern Argentina. From a total of 374 A. dubitatum ticks collected and evaluated by PCR for the presence of rickettsial DNA, 19 were positive for the presence of Rickettsia bellii DNA, two were positive for Rickettsia sp. strain COOPERI, and one was positive for the pathogenic Rickettsia sp. strain Atlantic rainforest. To our knowledge, this study is the first report of the presence of the human pathogen Rickettsia sp. strain Atlantic rainforest and Rickettsia sp. strain COOPERI in Argentina. Moreover, our findings posit A. dubitatum as a potential vector for this pathogenic strain of Rickettsia.

  11. Serosurveillance of Orientia tsutsugamushi and Rickettsia typhi in Bangladesh

    PubMed Central

    Maude, Rapeephan R.; Maude, Richard J.; Ghose, Aniruddha; Amin, M. Robed; Islam, M. Belalul; Ali, Mohammad; Bari, M. Shafiqul; Majumder, M. Ishaque; Tanganuchitcharnchai, Ampai; Dondorp, Arjen M.; Paris, Daniel H.; Bailey, Robin L.; Faiz, M. Abul; Blacksell, Stuart D.; Day, Nicholas P. J.

    2014-01-01

    Scrub and murine typhus infections are under-diagnosed causes of febrile illness across the tropics, and it is not known how common they are in Bangladesh. We conducted a prospective seroepidemiologic survey across six major teaching hospitals in Bangladesh by using an IgM enzyme-linked immunosorbent assay. Results indicated recent exposure (287 of 1,209, 23.7% seropositive for Orientia tsutsugamushi and 805 of 1,209, 66.6% seropositive for Rickettsia typhi). Seropositive rates were different in each region. However, there was no geographic clustering of seropositive results for both organisms. There was no difference between those from rural or urban areas. Rickettsia typhi seroreactivity was positively correlated with age. Scrub typhus and murine typhus should be considered as possible causes of infection in Bangladesh. PMID:25092819

  12. Serosurveillance of Orientia tsutsugamushi and Rickettsia typhi in Bangladesh.

    PubMed

    Maude, Rapeephan R; Maude, Richard J; Ghose, Aniruddha; Amin, M Robed; Islam, M Belalul; Ali, Mohammad; Bari, M Shafiqul; Majumder, M Ishaque; Tanganuchitcharnchai, Ampai; Dondorp, Arjen M; Paris, Daniel H; Bailey, Robin L; Faiz, M Abul; Blacksell, Stuart D; Day, Nicholas P J

    2014-09-01

    Scrub and murine typhus infections are under-diagnosed causes of febrile illness across the tropics, and it is not known how common they are in Bangladesh. We conducted a prospective seroepidemiologic survey across six major teaching hospitals in Bangladesh by using an IgM enzyme-linked immunosorbent assay. Results indicated recent exposure (287 of 1,209, 23.7% seropositive for Orientia tsutsugamushi and 805 of 1,209, 66.6% seropositive for Rickettsia typhi). Seropositive rates were different in each region. However, there was no geographic clustering of seropositive results for both organisms. There was no difference between those from rural or urban areas. Rickettsia typhi seroreactivity was positively correlated with age. Scrub typhus and murine typhus should be considered as possible causes of infection in Bangladesh. © The American Society of Tropical Medicine and Hygiene.

  13. Rickettsioses in Europe.

    PubMed

    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.

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

    PubMed

    Paddock, Christopher D; Fournier, Pierre-Edouard; Sumner, John W; Goddard, Jerome; Elshenawy, Yasmin; Metcalfe, Maureen G; Loftis, Amanda D; Varela-Stokes, Andrea

    2010-05-01

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

  15. Detecting Rickettsia parkeri Infection from Eschar Swab Specimens

    DTIC Science & Technology

    2013-05-01

    fever in North, Central, and South America were at- tributed to 1 pathogen, Rickettsia rickettsii, the cause of Rocky Mountain spotted fever ...life threatening. Rocky Mountain spotted fever is considered the most severe SFG rickettsiosis; mortality rate can be as high as 50% without adequate...rickettsii seropositivity among the general population without history of Rocky Mountain spotted fever , which suggests that they may have

  16. Rickettsia australis Activates Inflammasome in Human and Murine Macrophages

    PubMed Central

    Smalley, Claire; Bechelli, Jeremy; Rockx-Brouwer, Dedeke; Saito, Tais; Azar, Sasha R.; Ismail, Nahed; Walker, David H.; Fang, Rong

    2016-01-01

    Rickettsiae actively escape from vacuoles and replicate free in the cytoplasm of host cells, where inflammasomes survey the invading pathogens. In the present study, we investigated the interactions of Rickettsia australis with the inflammasome in both mouse and human macrophages. R. australis induced a significant level of IL-1β secretion by human macrophages, which was significantly reduced upon treatment with an inhibitor of caspase-1 compared to untreated controls, suggesting caspase-1-dependent inflammasome activation. Rickettsia induced significant secretion of IL-1β and IL-18 in vitro by infected mouse bone marrow-derived macrophages (BMMs) as early as 8–12 h post infection (p.i.) in a dose-dependent manner. Secretion of these cytokines was accompanied by cleavage of caspase-1 and was completely abrogated in BMMs deficient in caspase-1/caspase-11 or apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), suggesting that R. australis activate the ASC-dependent inflammasome. Interestingly, in response to the same quantity of rickettsiae, NLRP3-/- BMMs significantly reduced the secretion level of IL-1β compared to wild type (WT) controls, suggesting that NLRP3 inflammasome contributes to cytosolic recognition of R. australis in vitro. Rickettsial load in spleen, but not liver and lung, of R. australis-infected NLRP3-/- mice was significantly greater compared to WT mice. These data suggest that NLRP3 inflammasome plays a role in host control of bacteria in vivo in a tissue-specific manner. Taken together, our data, for the first time, illustrate the activation of ASC-dependent inflammasome by R. australis in macrophages in which NLRP3 is involved. PMID:27362650

  17. Artificial infection of the bed bug with Rickettsia parkeri.

    PubMed

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

    2012-07-01

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

  18. Rickettsia australis Activates Inflammasome in Human and Murine Macrophages.

    PubMed

    Smalley, Claire; Bechelli, Jeremy; Rockx-Brouwer, Dedeke; Saito, Tais; Azar, Sasha R; Ismail, Nahed; Walker, David H; Fang, Rong

    2016-01-01

    Rickettsiae actively escape from vacuoles and replicate free in the cytoplasm of host cells, where inflammasomes survey the invading pathogens. In the present study, we investigated the interactions of Rickettsia australis with the inflammasome in both mouse and human macrophages. R. australis induced a significant level of IL-1β secretion by human macrophages, which was significantly reduced upon treatment with an inhibitor of caspase-1 compared to untreated controls, suggesting caspase-1-dependent inflammasome activation. Rickettsia induced significant secretion of IL-1β and IL-18 in vitro by infected mouse bone marrow-derived macrophages (BMMs) as early as 8-12 h post infection (p.i.) in a dose-dependent manner. Secretion of these cytokines was accompanied by cleavage of caspase-1 and was completely abrogated in BMMs deficient in caspase-1/caspase-11 or apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), suggesting that R. australis activate the ASC-dependent inflammasome. Interestingly, in response to the same quantity of rickettsiae, NLRP3-/- BMMs significantly reduced the secretion level of IL-1β compared to wild type (WT) controls, suggesting that NLRP3 inflammasome contributes to cytosolic recognition of R. australis in vitro. Rickettsial load in spleen, but not liver and lung, of R. australis-infected NLRP3-/- mice was significantly greater compared to WT mice. These data suggest that NLRP3 inflammasome plays a role in host control of bacteria in vivo in a tissue-specific manner. Taken together, our data, for the first time, illustrate the activation of ASC-dependent inflammasome by R. australis in macrophages in which NLRP3 is involved.

  19. Limited transcriptional responses of Rickettsia rickettsii exposed to environmental stimuli.

    PubMed

    Ellison, Damon W; Clark, Tina R; Sturdevant, Daniel E; Virtaneva, Kimmo; Hackstadt, Ted

    2009-01-01

    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.

  20. Limited Transcriptional Responses of Rickettsia rickettsii Exposed to Environmental Stimuli

    PubMed Central

    Ellison, Damon W.; Clark, Tina R.; Sturdevant, Daniel E.; Virtaneva, Kimmo; Hackstadt, Ted

    2009-01-01

    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°C vs. 37°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°C vs. 4°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. PMID:19440298

  1. Detection, Isolation and Characterization of an Agent from Febrile Patients in Malaysia Serologically Reactive with Rickettsia sennetsu.

    DTIC Science & Technology

    1983-12-01

    1978. External layers of Rickettsia prowazekii and Rickettsia rickettsii . Occurrence of a slime layer. Infec. Immun. 22:233-246. Smith, D.K. and... RICKETTSIA SENNETSU FINAL COMPREHENSIVE REPORT MIODRAG RISTIC DECEMBER 1983 Supported by U.S. ARMY MEDICAL RESEARCH AND DEVELOPMENT COMMAND Fort Detrick...with Rickettsia sennetsu. " I hope that you will find it satisfactory. Sincerely yours, Miodrag Ristic, DVM, PhD Professor MR/ml Enclosures ,,i Z3

  2. Challenges Posed by Tick-Borne Rickettsiae: Eco-Epidemiology and Public Health Implications

    PubMed Central

    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

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

    PubMed Central

    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 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. PMID:26413074

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

    PubMed

    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.

  5. Detection of antibodies against spotted fever group Rickettsia (SFGR), typhus group Rickettsia (TGR), and Coxiella burnetii in human febrile patients in the Philippines.

    PubMed

    Camer, Gerry Amor; Alejandria, Marissa; Amor, Miguel; Satoh, Hiroshi; Muramatsu, Yasukazu; Ueno, Hiroshi; Morita, Chiharu

    2003-02-01

    A total of 157 sera from febrile patients in the Philippine General Hospital in Manila, Luzon, and the Northern Samar Provincial Hospital, the Philippines, were used. Serum antibodies against spotted fever group Rickettsia (SFGR) and typhus group Rickettsia (TGR) were detected by indirect immunofluorescence test. Antibody positive rates were 1.3% for SFGR (Rickettsia japonica) and 2.5% for TGR (R. typhus), respectively. Rickettsial antibodies in humans in the Philippines were found for the first time. These results underscore the need for further epidemiological study of clinical rickettsioses in the Philippines.

  6. Rickettsia bellii and Rickettsia amblyommii in Amblyomma ticks from the State of Rondônia, Western Amazon, Brazil.

    PubMed

    Labruna, Marcelo B; Whitworth, Ted; Bouyer, Donald H; McBride, Jere; Camargo, Luis Marcelo A; Camargo, Erney P; Popov, Vsevolod; Walker, David H

    2004-11-01

    This study evaluates the rickettsial presence in Amblyomma ticks from eight areas of the Amazon forest in Rondônia, Brazil. The following tick species (number in parentheses) were examined: Amblyomma ovale Koch (121), Amblyomma cajennense (F.) (41), Amblyomma naponense (Packard) (36), Amblyomma scalpturatum Neumann (35), Amblyomma oblongoguttatum Koch (30), Amblyomma incisum Neumann (27), Amblyomma rotundatum Koch (16), Amblyomma coelebs Neumann (10), and Amblyomma humerale Koch (6). Ticks were examined individually or in pools (2-10 ticks) by polymerase chain reaction (PCR) targeting the gltA gene. The PCR-determined minimal infection rate for each tick species was A. ovale 28%, A. cajennense 27%, A. naponense 0%, A. scalpturatum 11%, A. oblongoguttatum 3%, A. incisum 0%, A. rotundatum 87%, A. coelebs 10%, and A. humerale 50%. Partial sequences of the gltA gene of Rickettsia from A. ovale, A. scalpturatum, A. oblongoguttatum, A. rotundatum, and A. humerale were 99.9% (349/350) identical to Rickettsia bellii. DNA sequences of PCR products from A. cajennense and A. coelebs were 100% (350/350) identical to Rickettsia amblyommii. R. bellii organisms were isolated in Vero cells from A. scalpturatum, A. ovale, A. rotundatum, and A. oblongoguttatum, but only one of the isolates, cultured from A. scalpturatum, was established in continuous cell culture passage. R. amblyommii was isolated from A. cajennense and was successfully established in continuous passage in cell culture. R. amblyommii infection of Vero cells was analyzed by transmission electron microscopy. This study adds South America to the known geographic distribution of R. amblyommii and reports rickettsiae in six Amblyomma species for the first time.

  7. [The effect of body immunological reactivity on the persistence of rickettsiae].

    PubMed

    Klimchuk, M D; Kurganova, I I; Kos, E T; Basarab, N I

    1996-01-01

    Correlation between the rate of seeding of organs by rickettsiae and duration of the exciter persistence and condition of immunological reactivity was established using the experimental rickettsial infection as a model. When using the preparation which stimulates the immunity indices, we have revealed that the number of rickettsiae in organs was less and the release from them was faster than under immunodepression.

  8. A Typhus Group-Specific Protease Defies Reductive Evolution in Rickettsiae ▿ † ‡

    PubMed Central

    Ammerman, Nicole C.; Gillespie, Joseph J.; Neuwald, Andrew F.; Sobral, Bruno W.; Azad, Abdu F.

    2009-01-01

    Phylogenomics reveals extreme gene loss in typhus group (TG) rickettsiae relative to the levels for other rickettsial lineages. We report here a curious protease-encoding gene (ppcE) that is conserved only in TG rickettsiae. As a possible determinant of host pathogenicity, ppcE warrants consideration in the development of therapeutics against epidemic and murine typhus. PMID:19820087

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

    PubMed

    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.

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

    USDA-ARS?s Scientific Manuscript database

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

  11. Rickettsia felis Infection in Febrile Patients, Western Kenya, 2007–2010

    PubMed Central

    Maina, Alice N.; Knobel, Darryn L.; Jiang, Ju; Halliday, Jo; Feikin, Daniel R.; Cleaveland, Sarah; Ng’ang’a, Zipporah; Junghae, Muthoni; Breiman, Robert F.; Richards, Allen L.

    2012-01-01

    To determine previous exposure and incidence of rickettsial infections in western Kenya during 2007–2010, we conducted hospital-based surveillance. Antibodies against rickettsiae were detected in 57.4% of previously collected serum samples. In a 2008–2010 prospective study, Rickettsia felis DNA was 2.2× more likely to be detected in febrile than in afebrile persons. PMID:22304807

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

    PubMed

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

    2017-09-06

    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 non-exhaustive. Therefore, this survey was undertaken to investigate the presence of Rickettsia spp. in wild-living small rodents from south-western Poland. In total, 337 samples (193 from spleen and 144 from blood) obtained from 193 wild-living rodents: Apodemus agrarius, Apodemus flavicollis, and Myodes glareolus were tested by qPCR for Rickettsia spp. based on a fragment of gltA gene. The prevalence of infection was 17.6% (34/193). Subsequently, the positive samples were analysed by conventional PCR targeting the gltA gene fragment. The genus Rickettsia was confirmed by sequence analysis in four samples from the blood. In two blood samples from A. agrarius, the identified pathogen was Rickettsia helvetica. The Rickettsia obtained from A. flavicollis was assigned to Rickettsia felis-like organisms group. One isolate from A. agrarius could be determined only to the genus level. This study shows the presence of Rickettsia DNA in tissues of wild-living rodents, suggesting some potential role of these animals in temporarily maintaining and spreading the bacteria in enzootic cycles.

  13. High prevalence of Rickettsia spp. infections in small mammals in Taiwan.

    PubMed

    Kuo, Chi-Chien; Shu, Pei-Yun; Mu, Jung-Jung; Wang, Hsi-Chieh

    2015-01-01

    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.

  14. Rickettsia spp. in seabird ticks from western Indian Ocean islands, 2011-2012.

    PubMed

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

    2014-05-01

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

  15. Molecular method for identification of Rickettsia species in clinical and environmental samples.

    PubMed

    Jado, Isabel; Escudero, Raquel; Gil, Horacio; Jiménez-Alonso, María Isabel; Sousa, Rita; García-Pérez, Ana L; Rodríguez-Vargas, Manuela; Lobo, Bruno; Anda, Pedro

    2006-12-01

    We present a PCR method targeting the 23S-5S internal transcribed spacer coupled with reverse line blotting that allows Rickettsia species detection and identification in a single step. The method is highly sensitive and specific in identifying Rickettsia species from both patient and environmental samples. The generic approach used allowed us to identify new pathogens.

  16. [Experimental study of the inoculative transmission of Rickettsia typhi by gamasid mites (Gamasidae) Ornithonyssus bacoti].

    PubMed

    Grabarev, P A; Suroviatkin, A V; Tikhonova, Iu Iu; Mishchenko, O A; Potapenko, O V

    2009-01-01

    The authors' studies have established that the concentration of Rickettsia typhi may increase about 100-fold in the infected Ornithonyssus bacoti mites. At the time, when on feeding 20 to 200 adult mites on guinea-pigs and albino rats 4 to 36 days after inoculation, they did not transmit Rickettsia typhi on blood sucking.

  17. STUDIES ON THE CULTIVATION OF THE TYPHUS FEVER RICKETTSIA IN THE PRESENCE OF LIVE TISSUE

    PubMed Central

    Nigg, Clara; Landsteiner, K.

    1932-01-01

    1. Rickettsia prowazeki can be cultivated for many generations in vitro, without diminution in numbers or virulence, in media similar to those described by Maitland, Rivers, and others for the cultivation of certain viruses. In all probability, such cultures can be maintained indefinitely. 2. It has been impossible, thus far, to cultivate the typhus rickettsia without employing living tissue. PMID:19870013

  18. Presence of Rickettsia felis in the Cat Flea from Southwestern Europe1

    PubMed Central

    Muniain, Miguel A.; Pérez, Jesús M.; Pachón, Jerónimo

    2002-01-01

    Rickettsia felis, formerly called ELB agent, was identified by using molecular biology techniques in the cat flea (Ctenocephalides felis felis) from southwestern Spain. For the first time this flea-transmitted rickettsia has been detected within its vector in Eurasia. PMID:11749758

  19. Plasmids of the pRM/pRF family occur in diverse Rickettsia species.

    PubMed

    Baldridge, Gerald D; Burkhardt, Nicole Y; Felsheim, Roderick F; Kurtti, Timothy J; Munderloh, Ulrike G

    2008-02-01

    The recent discoveries of the pRF and pRM plasmids of Rickettsia felis and R. monacensis have contravened the long-held dogma that plasmids are not present in the bacterial genus Rickettsia (Rickettsiales; Rickettsiaceae). We report the existence of plasmids in R. helvetica, R. peacockii, R. amblyommii, and R. massiliae isolates from ixodid ticks and in an R. hoogstraalii isolate from an argasid tick. R. peacockii and four isolates of R. amblyommii from widely separated geographic locations contained plasmids that comigrated with pRM during pulsed-field gel electrophoresis and larger plasmids with mobilities similar to that of pRF. The R. peacockii plasmids were lost during long-term serial passage in cultured cells. R. montanensis did not contain a plasmid. Southern blots showed that sequences similar to those of a DnaA-like replication initiator protein, a small heat shock protein 2, and the Sca12 cell surface antigen genes on pRM and pRF were present on all of the plasmids except for that of R. massiliae, which lacked the heat shock gene and was the smallest of the plasmids. The R. hoogstraalii plasmid was most similar to pRM and contained apparent homologs of proline/betaine transporter and SpoT stringent response genes on pRM and pRF that were absent from the other plasmids. The R. hoogstraalii, R. helvetica, and R. amblyommii plasmids contained homologs of a pRM-carried gene similar to a Nitrobacter sp. helicase RecD/TraA gene, but none of the plasmids hybridized with a probe derived from a pRM-encoded gene similar to a Burkholderia sp. transposon resolvase gene.

  20. Characterization and localization of Rickettsia sp. in water beetles of genus Deronectes (Coleoptera: Dytiscidae).

    PubMed

    Küchler, Stefan Martin; Kehl, Siegfried; Dettner, Konrad

    2009-05-01

    In the present study, Rickettsia sp. was detected in four water beetles of the genus Deronectes (Dytiscidae) for the first time. Rickettsiae were found in 100% of examined specimens of Deronectes platynotus (45/45), 39.4% of Deronectes aubei (28/71), 40% of Deronectes delarouzei (2/5) and 33.3% of Deronectes semirufus (1/3). Analysis of 16S rRNA gene sequences revealed a phylogenetic relationship with rickettsial isolates of Limonia chorea (Diptera), tentatively classified as members of the basal ancestral group. Phylogenetic analysis of the gltA (citrate synthase) gene sequences showed that Deronectes symbionts were closest to bacterial symbionts from spiders. Ultrastructural examinations revealed typical morphological features and intracellular arrangements of rickettsiae. The distribution, transmission and localization of Rickettsia sp. in D. platynotus were studied using a diagnostic PCR assay and FISH. Eggs from infected females of D. platynotus were all Rickettsia-positive, indicative of a vertical transmission.

  1. Seroprevalence of Rickettsia bellii and Rickettsia felis in dogs, São José dos Pinhais, State of Paraná, Brazil.

    PubMed

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

    2010-01-01

    Brazilian spotted fever (BSF) is a vector-borne zoonosis caused by Rickettsia rickettsii bacteria. Dogs can be host sentinels for this bacterium. The aim of the study was to determine the presence of antibodies against Rickettsia spp. in dogs from the city of São José dos Pinhais, State of Paraná, Southern Brazil, where a human case of BSF was first reported in the state. Between February 2006 and July 2007, serum samples from 364 dogs were collected and tested at 1:64 dilutions by indirect immunofluorescence assay (IFA) against R. rickettsii and R. parkeri. All sera that reacted at least to one of Rickettsia species were tested against the six main Rickettsia species identified in Brazil: R. rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii and R. felis. Sixteen samples (4.4%) reacted to at least one Rickettsia species. Among positive animals, two dogs (15.5%) showed suggestive titers for R. bellii exposure. One sample had a homologous reaction to R. felis, a confirmed human pathogen. Although Rickettsia spp. circulation in dogs in the area studied may be considered at low prevalence, suggesting low risk of human infection, the present data demonstrate for the first time the exposure of dogs to R. bellii and R. felis in Southern Brazil.

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

    PubMed

    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

  3. Human Infection with Rickettsia felis, Kenya

    DTIC Science & Technology

    2010-07-01

    also investigated the occurrence of other causes of fever that are not routinely tested tor at the local hospitals, including Emerging Infectious...sheep, goats, and camels; and carries a wide range of wi ldl ife. including zebras, ante- lopes. waterbucks. giraffes, warthogs, monkeys. gerenuks...age (inpatients or outpa- tients). had an axillary temperature ~38°C, had a negative test for malaria by blood smear, and had a history of animal

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

    PubMed

    Felsheim, Roderick F; Kurtti, Timothy J; Munderloh, Ulrike G

    2009-12-21

    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.

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

    PubMed

    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.

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

    PubMed

    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

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

    PubMed

    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.

  8. Characterization of Spotted Fever Group Rickettsiae in Flea and Tick Specimens from Northern Peru

    PubMed Central

    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

    Evidence of spotted fever group (SFG) rickettsiae was obtained from flea pools and individual ticks collected at three sites in northwestern Peru within 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 (htrA) as well as pairwise nucleotide sequence homology with one or more of the following genes: gltA, ompA, and ompB. Amplification and sequencing of portions of the htrA and ompA genes in pooled samples (2 of 59) taken from fleas identified the pathogen Rickettsia felis. Four tick samples yielded molecular evidence of SFG rickettsiae. Fragments of the ompA (540-bp) and ompB (2,484-bp) genes were amplified from a single Amblyomma maculatum tick (tick 124) and an Ixodes boliviensis tick (tick 163). The phylogenetic relationships between the rickettsiae in these samples and other rickettsiae were determined after comparison of their ompB sequences by the neighbor-joining method. The dendrograms generated showed that the isolates exhibited close homology (97%) to R. aeschlimannii and R. rhipicephali. Significant bootstrap values supported clustering adjacent to this nodule of the SFG rickettsiae. While the agents identified in the flea and tick samples have not been linked to human cases in the area, these results demonstrate for the first time that at least two SFG rickettsia agents were circulating in northern Peru at the time of the outbreak. Furthermore, molecular analysis of sequences derived from the two separate species of hard ticks identified a possibly novel member of the SFG rickettsiae. PMID:15528680

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

    PubMed Central

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

    2016-01-01

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

  10. Dissemination of Spotted Fever Rickettsia Agents in Europe by Migrating Birds

    PubMed Central

    Elfving, Karin; Olsen, Björn; Bergström, Sven; Waldenström, Jonas; Lundkvist, Åke; Sjöstedt, Anders; Mejlon, Hans; Nilsson, Kenneth

    2010-01-01

    Migratory birds are known to play a role as long-distance vectors for many microorganisms. To investigate whether this is true of rickettsial agents as well, we characterized tick infestation and gathered ticks from 13,260 migratory passerine birds in Sweden. A total of 1127 Ixodes spp. ticks were removed from these birds and the extracted DNA from 957 of them was available for analyses. The DNA was assayed for detection of Rickettsia spp. using real-time PCR, followed by DNA sequencing for species identification. Rickettsia spp. organisms were detected in 108 (11.3%) of the ticks. Rickettsia helvetica, a spotted fever rickettsia associated with human infections, was predominant among the PCR-positive samples. In 9 (0.8%) of the ticks, the partial sequences of 17kDa and ompB genes showed the greatest similarity to Rickettsia monacensis, an etiologic agent of Mediterranean spotted fever-like illness, previously described in southern Europe as well as to the Rickettsia sp.IrITA3 strain. For 15 (1.4%) of the ticks, the 17kDa, ompB, gltA and ompA genes showed the greatest similarity to Rickettsia sp. strain Davousti, Rickettsia japonica and Rickettsia heilongjiangensis, all closely phylogenetically related, the former previously found in Amblyomma tholloni ticks in Africa and previously not detected in Ixodes spp. ticks. The infestation prevalence of ticks infected with rickettsial organisms was four times higher among ground foraging birds than among other bird species, but the two groups were equally competent in transmitting Rickettsia species. The birds did not seem to serve as reservoir hosts for Rickettsia spp., but in one case it seems likely that the bird was rickettsiemic and that the ticks had acquired the bacteria from the blood of the bird. In conclusion, migratory passerine birds host epidemiologically important vector ticks and Rickettsia species and contribute to the geographic distribution of spotted fever rickettsial agents and their diseases. PMID

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

    PubMed

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

    2016-08-01

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

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

    PubMed

    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.

  13. Managing iron supply during the infection cycle of a flea borne pathogen, Bartonella henselae.

    PubMed

    Liu, Mafeng; Biville, Francis

    2013-01-01

    Bartonella are hemotropic bacteria responsible for emerging zoonoses. Most Bartonella species appear to share a natural cycle that involves an arthropod transmission, followed by exploitation of a mammalian host in which they cause long-lasting intra-erythrocytic bacteremia. Persistence in erythrocytes is considered an adaptation to transmission by bloodsucking arthropod vectors and a strategy to obtain heme required for Bartonella growth. Bartonella genomes do not encode for siderophore biosynthesis or a complete iron Fe(3+) transport system. Only genes, sharing strong homology with all components of a Fe(2+) transport system, are present in Bartonella genomes. Also, Bartonella genomes encode for a complete heme transport system. Bartonella must face various environments in their hosts and vectors. In mammals, free heme and iron are rare and oxygen concentration is low. In arthropod vectors, toxic heme levels are found in the gut where oxygen concentration is high. Bartonella genomes encode for 3-5 heme-binding proteins. In Bartonella henselae heme-binding proteins were shown to be involved in heme uptake process, oxidative stress response, and survival inside endothelial cells and in the flea. In this report, we discuss the use of the heme uptake and storage system of B. henselae during its infection cycle. Also, we establish a comparison with the iron and heme uptake systems of Yersinia pestis used during its infection cycle.

  14. Prostatitis, steatitis, and diarrhea in a dog following presumptive flea-borne transmission of Bartonella henselae.

    PubMed

    Balakrishnan, Nandhakumar; Pritchard, Jessica; Ericson, Marna; Grindem, Carol; Phillips, Kathryn; Jennings, Samuel; Mathews, Kyle; Tran, Huy; Birkenheuer, Adam J; Breitschwerdt, Edward B

    2014-09-01

    Bartonella henselae is increasingly associated with a variety of pathological entities, which are often similar in dogs and human patients. Following an acute flea infestation, a dog developed an unusual clinical presentation for canine bartonellosis. Comprehensive medical, microbiological, and surgical interventions were required for diagnosis and to achieve a full recovery.

  15. Classic flea-borne transmission does not drive plague epizootics in prairie dogs.

    PubMed

    Webb, Colleen T; Brooks, Christopher P; Gage, Kenneth L; Antolin, Michael F

    2006-04-18

    We lack a clear understanding of the enzootic maintenance of the bacterium (Yersinia pestis) that causes plague and the sporadic epizootics that occur in its natural rodent hosts. A key to elucidating these epidemiological dynamics is determining the dominant transmission routes of plague. Plague can be acquired from the bites of infectious fleas (which is generally considered to occur via a blocked flea vector), inhalation of infectious respiratory droplets, or contact with a short-term infectious reservoir. We present results from a plague modeling approach that includes transmission from all three sources of infection simultaneously and uses sensitivity analysis to determine their relative importance. Our model is completely parameterized by using data from the literature and our own field studies of plague in the black-tailed prairie dog (Cynomys ludovicianus). Results of the model are qualitatively and quantitatively consistent with independent data from our field sites. Although infectious fleas might be an important source of infection and transmission via blocked fleas is a dominant paradigm in the literature, our model clearly predicts that this form of transmission cannot drive epizootics in prairie dogs. Rather, a short-term reservoir is required for epizootic dynamics. Several short-term reservoirs have the potential to affect the prairie dog system. Our model predictions of the residence time of the short-term reservoir suggest that other small mammals, infectious prairie dog carcasses, fleas that transmit plague without blockage of the digestive tract, or some combination of these three are the most likely of the candidate infectious reservoirs.

  16. Managing iron supply during the infection cycle of a flea borne pathogen, Bartonella henselae

    PubMed Central

    Liu, MaFeng; Biville, Francis

    2013-01-01

    Bartonella are hemotropic bacteria responsible for emerging zoonoses. Most Bartonella species appear to share a natural cycle that involves an arthropod transmission, followed by exploitation of a mammalian host in which they cause long-lasting intra-erythrocytic bacteremia. Persistence in erythrocytes is considered an adaptation to transmission by bloodsucking arthropod vectors and a strategy to obtain heme required for Bartonella growth. Bartonella genomes do not encode for siderophore biosynthesis or a complete iron Fe3+ transport system. Only genes, sharing strong homology with all components of a Fe2+ transport system, are present in Bartonella genomes. Also, Bartonella genomes encode for a complete heme transport system. Bartonella must face various environments in their hosts and vectors. In mammals, free heme and iron are rare and oxygen concentration is low. In arthropod vectors, toxic heme levels are found in the gut where oxygen concentration is high. Bartonella genomes encode for 3–5 heme-binding proteins. In Bartonella henselae heme-binding proteins were shown to be involved in heme uptake process, oxidative stress response, and survival inside endothelial cells and in the flea. In this report, we discuss the use of the heme uptake and storage system of B. henselae during its infection cycle. Also, we establish a comparison with the iron and heme uptake systems of Yersinia pestis used during its infection cycle. PMID:24151576

  17. Flea-borne Bartonella grahamii and Bartonella taylorii in bank voles.

    PubMed

    Bown, Kevin J; Bennet, Malcolm; Begon, Michael

    2004-04-01

    Bartonella species are increasingly associated with a range of human and animal diseases. Despite this, we have a poor understanding of the ecology and epidemiology of many species, especially those circulating in wild populations. Previous studies have demonstrated that a diverse range of Bartonella species are abundant in wild rodent populations; little is known regarding their modes of transmission, although both direct and indirect routes have been suggested. In this study, with bank voles (Clethrionomys glareolus) as the host species, we demonstrate that the rodent flea Ctenophthalmus nobilis is a competent vector of at least two Bartonella species, B. grahamii, which has previously been associated with human infection, and B. taylorii. In contrast, no evidence of either horizontal or vertical transmission was seen in bank voles inoculated with B. taylorii maintained in an arthropod-free environment; this finding suggests that fleas may be essential for transmitting some Bartonella species.

  18. Flea-borne Bartonella grahamii and Bartonella taylorii in Bank Voles

    PubMed Central

    Bennett, Malcolm; Begon, Michael

    2004-01-01

    Bartonella species are increasingly associated with a range of human and animal diseases. Despite this, we have a poor understanding of the ecology and epidemiology of many species, especially those circulating in wild populations. Previous studies have demonstrated that a diverse range of Bartonella species are abundant in wild rodent populations; little is known regarding their modes of transmission, although both direct and indirect routes have been suggested. In this study, with bank voles (Clethrionomys glareolus) as the host species, we demonstrate that the rodent flea Ctenophthalmus nobilis is a competent vector of at least two Bartonella species, B. grahamii, which has previously been associated with human infection, and B. taylorii. In contrast, no evidence of either horizontal or vertical transmission was seen in bank voles inoculated with B. taylorii maintained in an arthropod-free environment; this finding suggests that fleas may be essential for transmitting some Bartonella species. PMID:15200860

  19. Classic flea-borne transmission does not drive plague epizootics in prairie dogs

    PubMed Central

    Webb, Colleen T.; Brooks, Christopher P.; Gage, Kenneth L.; Antolin, Michael F.

    2006-01-01

    We lack a clear understanding of the enzootic maintenance of the bacterium (Yersinia pestis) that causes plague and the sporadic epizootics that occur in its natural rodent hosts. A key to elucidating these epidemiological dynamics is determining the dominant transmission routes of plague. Plague can be acquired from the bites of infectious fleas (which is generally considered to occur via a blocked flea vector), inhalation of infectious respiratory droplets, or contact with a short-term infectious reservoir. We present results from a plague modeling approach that includes transmission from all three sources of infection simultaneously and uses sensitivity analysis to determine their relative importance. Our model is completely parameterized by using data from the literature and our own field studies of plague in the black-tailed prairie dog (Cynomys ludovicianus). Results of the model are qualitatively and quantitatively consistent with independent data from our field sites. Although infectious fleas might be an important source of infection and transmission via blocked fleas is a dominant paradigm in the literature, our model clearly predicts that this form of transmission cannot drive epizootics in prairie dogs. Rather, a short-term reservoir is required for epizootic dynamics. Several short-term reservoirs have the potential to affect the prairie dog system. Our model predictions of the residence time of the short-term reservoir suggest that other small mammals, infectious prairie dog carcasses, fleas that transmit plague without blockage of the digestive tract, or some combination of these three are the most likely of the candidate infectious reservoirs. PMID:16603630

  20. Prostatitis, Steatitis, and Diarrhea in a Dog following Presumptive Flea-Borne Transmission of Bartonella henselae

    PubMed Central

    Balakrishnan, Nandhakumar; Pritchard, Jessica; Ericson, Marna; Grindem, Carol; Phillips, Kathryn; Jennings, Samuel; Mathews, Kyle; Tran, Huy; Birkenheuer, Adam J.

    2014-01-01

    Bartonella henselae is increasingly associated with a variety of pathological entities, which are often similar in dogs and human patients. Following an acute flea infestation, a dog developed an unusual clinical presentation for canine bartonellosis. Comprehensive medical, microbiological, and surgical interventions were required for diagnosis and to achieve a full recovery. PMID:24920774

  1. Hfq Regulates Biofilm Gut Blockage That Facilitates Flea-Borne Transmission of Yersinia pestis

    PubMed Central

    Rempe, Katherine A.; Hinz, Angela K.

    2012-01-01

    The plague bacillus Yersinia pestis can achieve transmission by biofilm blockage of the foregut proventriculus of its flea vector. Hfq is revealed to be essential for biofilm blockage formation and acquisition and fitness of Y. pestis during flea gut infection, consistent with posttranscriptional regulatory mechanisms in plague transmission. PMID:22328669

  2. Anthropogenic disturbance and the risk of flea-borne disease transmission

    Treesearch

    Megan M. Friggens; Paul Beier

    2010-01-01

    Anthropogenic disturbance may lead to the spread of vector-borne diseases through effects on pathogens, vectors, and hosts. Identifying the type and extent of vector response to habitat change will enable better and more accurate management strategies for anthropogenic disease spread. We compiled and analyzed data from published empirical studies to test for patterns...

  3. Experimental infection of the opossum Didelphis aurita by Rickettsia felis, Rickettsia bellii, and Rickettsia parkeri and evaluation of the transmission of the infection to ticks Amblyomma cajennense and Amblyomma dubitatum.

    PubMed

    Horta, Maurício C; Sabatini, Guilherme S; Moraes-Filho, Jonas; Ogrzewalska, Maria; Canal, Raoní B; Pacheco, Richard C; Martins, Thiago F; Matushima, Eliana R; Labruna, Marcelo B

    2010-12-01

    This work evaluated the infection of opossums (Didelphis aurita) by Rickettsia felis, Rickettsia bellii, and Rickettsia parkeri and their role as amplifier hosts for horizontal transmission to Amblyomma cajennense and/or Amblyomma dubitatum ticks. Infection in D. aurita was induced by intraperitoneal inoculation with R. felis (n = 4 opossums), R. bellii (n = 4), and R. parkeri (n = 2). Another group of six opossums were inoculated intraperitoneally with Leibovitz-15 sterile culture medium, representing the uninfected groups (n = 2 opossums simultaneously to each infected group). Opossum blood samples collected during the study were used for DNA extraction, followed by real-time polymerase chain reaction targeting the rickettsial gene gltA, hematology, and detection of Rickettsia spp.-reactive antibodies by indirect immunofluorescence assay. Opossums were infested with uninfected A. cajennense and/or A. dubitatum for 30 days postinoculation (DPI). Flat ticks molted from ticks fed on opossums were allowed to feed on uninfected rabbits, which were tested for seroconversion by immunofluorescence assay. Samples of flat ticks were also tested by real-time polymerase chain reaction. Inoculated opossums showed no clinical abnormalities. Antibodies to Rickettsia spp. were first detected at the second to fourth DPI, with detectable titers until the 150th DPI. Rickettsemia was detected only in one opossum inoculated with R. parkeri, at the eighth DPI. Only one A. cajennense tick (2.0%) previously fed on a R. parkeri-inoculated opossum became infected. None of the rabbits infested with opossum-derived ticks seroconverted. The study demonstrated that R. felis, R. bellii, and R. parkeri were capable to produce antibody response in opossums, however, with undetectable rickettsemia for R. felis and R. bellii, and very low rickettsemia for R. parkeri. Further studies must be done with different strains of these rickettsiae, most importantly the strains that have

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

    PubMed Central

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

    2009-01-01

    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]. PMID:19379498

  5. Detection of Rickettsia parkeri from within Piura, Peru, and the First Reported Presence of Candidatus Rickettsia andeanae in the Tick Rhipicephalus sanguineus

    PubMed Central

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

    2013-01-01

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

  6. A Focus of Dogs and Rickettsia massiliae–Infected Rhipicephalus sanguineus in California

    PubMed Central

    Beeler, Emily; Abramowicz, Kyle F.; Zambrano, Maria L.; Sturgeon, Michele M.; Khalaf, Nada; Hu, Renjie; Dasch, Gregory A.; Eremeeva, Marina E.

    2011-01-01

    A recurrent focus of Rhipicephalus sanguineus infestation was investigated in a suburban area of southern California after reports of suspected Rocky Mountain spotted fever in two dogs on the same property. Abundant quantities of Rh. sanguineus were collected on the property and repeatedly from each dog, and Rickettsia massiliae DNA was detected by polymerase chain reaction (PCR). Whole blood and serum samples from four dogs were tested by using PCR and microimmunofluorescent assay for antibodies against spotted fever group rickettsiae. Serum samples from all four dogs contained antibodies reactive with R. massiliae, R. rhipicephali, R. rickettsii, and 364D Rickettsia but no rickettsial DNA was detected by PCR of blood samples. Serum cross-absorption and Western blot assays implicated R. massiliae as the most likely spotted fever group rickettsiae responsible for seropositivity. To our knowledge, this is the first detection of R. massiliae in ticks in California. PMID:21292893

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

    PubMed

    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.

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

    PubMed

    Marié, Jean-Lou; Davoust, Bernard; Socolovschi, Cristina; Mediannikov, Oleg; Roqueplo, Cédric; Beaucournu, Jean-Claude; Raoult, Didier; Parola, Philippe

    2012-01-01

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

  9. Clinical and laboratorial evidence of Rickettsia felis infections in Latin America.

    PubMed

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

    2004-01-01

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

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

    PubMed

    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.

  11. Detection of Rickettsia amblyommii in association with a tick bite rash.

    PubMed

    Billeter, Sarah A; Blanton, Hunter L; Little, Susan E; Levy, Michael G; Breitschwerdt, Edward B

    2007-01-01

    In the summer of 2006, an Amblyomma americanum tick was removed from a woman in central North Carolina, who subsequently developed a rash at the site of tick attachment. When examined by polymerase chain reaction (PCR) for Borrelia, Anaplasma, Ehrlichia, Babesia, Rickettsia, and Bartonella DNA, only the Rickettsia primers generated an amplicon, which was identified as "R. amblyommii" by sequencing. To our knowledge, this is the first case in which R. amblyommii was temporally associated with a rash.

  12. Prevalence of antibodies to spotted fever group rickettsiae along the eastern coast of the Adriatic sea.

    PubMed Central

    Radulovic, S; Walker, D H; Weiss, K; Dzelalija, B; Morovic, M

    1993-01-01

    A seroepidemiological survey in coastal Croatia detected antibodies reactive with Rickettsia conorii in 4.2% of sera by immunofluorescence assay and in 5.0% of sera by enzyme immunoassay. Western immunoblotting demonstrated antibodies to the 120-kDa surface protein in all 20 positive serum samples examined and to rickettsial lipopolysaccharide in 3 of these serum samples. Humans in this area are clearly being exposed to spotted fever rickettsiae. PMID:8370756

  13. Molecular evidence of spotted fever group rickettsiae and Anaplasmataceae from ticks and stray dogs in Bangladesh.

    PubMed

    Qiu, Yongjin; Nakao, Ryo; Thu, May June; Akter, Shirin; Alam, Mohammad Zahangir; Kato, Satomi; Katakura, Ken; Sugimoto, Chihiro

    2016-03-01

    Emerging tick-borne diseases (TBDs) are important foci for human and animal health worldwide. However, these diseases are sometimes over looked, especially in countries with limited resources to perform molecular-based surveys. The aim of this study was to detect and characterize spotted fever group (SFG) rickettsiae and Anaplasmataceae in Bangladesh, which are important tick-borne pathogens for humans and animals worldwide. A total of 50 canine blood samples, 15 ticks collected from dogs, and 154 ticks collected from cattle were screened for the presence of SFG rickettsiae and Anaplasmataceae using molecular-based methods such as PCR and real-time PCR. The sequence analysis of the amplified products detected two different genotypes of SFG rickettsiae in ticks from cattle. The genotype detected in Rhipicephalus microplus was closely related to Rickettsia monacensis, while the genotype detected in Haemaphysalis bispinosa was closely related to Rickettsia sp. found in Korea and Japan. Anaplasma bovis was detected in canine blood and ticks (Rhipicephalus sanguineus and H. bispinosa). Unexpectedly, the partial genome sequence of Wolbachia sp., presumably associated with the nematode Dirofilaria immitis, was identified in canine blood. The present study provides the first molecular evidence of SFG rickettsiae and A. bovis in Bangladesh, indicating the possible emergence of previously unrecognized TBDs in this country.

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

    PubMed

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

    2017-01-10

    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.

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

    SciTech Connect

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

    1987-12-15

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

  16. Amblyomma sculptum: genetic diversity and rickettsias in the Brazilian Cerrado biome.

    PubMed

    Bitencourth, K; Amorim, M; DE Oliveira, S V; Caetano, R L; Voloch, C M; Gazêta, G S

    2017-07-28

    Amblyomma sculptum (Ixodida: Ixodidae) Berlese, 1888 is the most important tick vector in Brazil, transmitting the bioagent of the most severe form of spotted fever (SF) in part of the Cerrado (in the states of Minas Gerais and São Paulo). In another part of the Cerrado (Central-West region of Brazil), a milder form of SF has been recorded. However, neither the rickettsia nor the vector involved have been characterized. The aim of the current study was to analyse genetic variation and the presence of rickettsia in A. sculptum in Cerrado, from silent areas and with the milder form of SF. Samples were subjected to DNA extraction, amplification and sequencing of 12S rDNA, cytochrome oxidase subunit II and D-loop mitochondrial genes (for tick population analyses), and gltA, htrA, ompA and gene D (sca4) genes for rickettsia researches. Exclusive haplotypes with low frequencies, high haplotype diversity and low nucleotide diversity, star-shaped networks and significant results in neutrality tests indicate A. sculptum population expansions in some areas. Rickettsia amblyommatis, Candidatus Rickettsia andeanae and Rickettsia felis were detected. The A. sculptum diversity is not geographically, or biome delimited, pointing to a different potential in vector capacity, possibly associated with differing tick genetic profiles. © 2017 The Royal Entomological Society.

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

    PubMed Central

    Whiley, Harriet; Custance, Georgie; Graves, Stephen; Stenos, John; Taylor, Michael; Ross, Kirstin; Gardner, Michael G.

    2016-01-01

    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. PMID:27338482

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

    PubMed

    Zemtsova, Galina E; Gleim, Elizabeth; Yabsley, Michael J; Conner, L Mike; Mann, Tom; Brown, Mary D; Wendland, Lori; Levin, Michael L

    2012-05-01

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

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

    PubMed

    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.

  20. High prevalence of "Candidatus Rickettsia amblyommii" in Amblyomma ticks from a Spotted Fever Endemic Region in North Argentina.

    PubMed

    Mastropaolo, Mariano; Tarragona, Evelina L; Silaghi, Cornelia; Pfister, Kurt; Thiel, Claudia; Nava, Santiago

    2016-06-01

    Ticks from an endemic Spotted Fever region in Argentina were analysed by PCR for Spotted Fever Group Rickettsiae. DNA of "Candidatus Rickettsia amblyommii" was found in 21.3% of Amblyomma hadanii and in 44.0% of A. neumanni. Amblyomma sculptum (formerly A. cajennense) and Haemaphysalis juxtakochi were negative for rickettsial DNA. DNA of Rickettsia rickettsii, the etiological agent of the clinical cases reported within the studied region was not detected in the analysed sample.

  1. An Unusual Cutaneous Manifestation in a Patient with Murine Typhus

    PubMed Central

    Blanton, Lucas S.; Lea, Alfred S.; Kelly, Brent C.; Walker, David H.

    2015-01-01

    Murine typhus is a flea-borne febrile illness caused by Rickettsia typhi. Although often accompanied by rash, an inoculation lesion has not been observed as it is with many tick- and mite-transmitted rickettsioses. We describe a patient with murine typhus and an unusual cutaneous manifestation at the site of rickettsial inoculation. PMID:26416115

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

    PubMed

    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

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

    PubMed Central

    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

  4. Experimental Infection of Amblyomma aureolatum Ticks with Rickettsia rickettsii

    PubMed Central

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

    2011-01-01

    We experimentally infected Amblyomma aureolatum ticks with the bacterium Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever (RMSF). These ticks are a vector for RMSF in Brazil. R. rickettsii was efficiently conserved by both transstadial maintenance and vertical (transovarial) transmission to 100% of the ticks through 4 laboratory generations. However, lower reproductive performance and survival of infected females was attributed to R. rickettsii infection. Therefore, because of the high susceptibility of A. aureolatum ticks to R. rickettsii infection, the deleterious effect that the bacterium causes in these ticks may contribute to the low infection rates (<1%) usually reported among field populations of A. aureolatum ticks in RMSF-endemic areas of Brazil. Because the number of infected ticks would gradually decrease after each generation, it seems unlikely that A. aureolatum ticks could sustain R. rickettsii infection over multiple successive generations solely by vertical transmission. PMID:21529391

  5. Molecular typing of novel Rickettsia rickettsii isolates from Arizona.

    PubMed

    Eremeeva, Marina E; Bosserman, Elizabeth; Zambrano, Maria; Demma, Linda; Dasch, Gregory A

    2006-10-01

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

  6. Experimental infection of Amblyomma aureolatum ticks with Rickettsia rickettsii.

    PubMed

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

    2011-05-01

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

  7. Vectorial competence of Amblyomma tonelliae to transmit Rickettsia rickettsii.

    PubMed

    Tarragona, E L; Soares, J F; Costa, F B; Labruna, M B; Nava, S

    2016-12-01

    The aim of this work was to test the vectorial competence of Amblyomma tonelliae (Ixodida: Ixodidae) to transmit Rickettsia rickettsii (Rickettsiales: Rickettsiaceae), the agent of Rocky Mountain spotted fever (RMSF). All parasitic stages of A. tonelliae were exposed to R. rickettsii by allowing each stage to feed on hosts inoculated with this pathogen. Thereafter, ticks were fed on uninfected hosts. All stages of A. tonelliae were able to acquire the R. rickettsii infection and maintain it by transstadial and transovarial transmission. When infected ticks fed on uninfected hosts, the hosts developed rickettsiosis disease. This study demonstrates the vectorial competence of A. tonelliae to transmit R. rickettsii. These results have epidemiological relevance because A. tonelliae is one of the tick species most likely to infest humans in Argentina, including in areas in which RMSF has been reported.

  8. Exposure of dogs to spotted fever group rickettsiae in urban sites associated with human rickettsioses in Costa Rica.

    PubMed

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

    2016-07-01

    The zoonotic transmission cycles of Rickettsia rickettsii and other spotted fever group (SFG) rickettsiae in Latin America have usually been associated with rural or sylvatic environments, although domestic dogs can be implicated in more populated settings. In this study, exposure of dogs to SFG rickettsiae in the Greater Metropolitan Area of Costa Rica was investigated. Dogs from sites associated with human cases and from dog shelters were evaluated by indirect immunofluorescence assay (IFA) using antigen of SFG rickettsiae. Rickettsia spp. were detected in ectoparasites by polymerase chain reaction (PCR). A total 18.5% (31/168) of dogs associated with human cases and 6.8% (11/161) of dogs in shelters had IgG end titers≥64 to Rickettsia spp. The odds of being seropositive were greater in dogs from areas associated with human cases when compared to shelters (OR: 3.2; 95% C.I: 1.5-5.6). Rhipicephalus sanguineus sensu lato (s. l.) was present in all sites associated with human cases. Rickettsia felis URRWXCal2 and R. felis-like RF2125 were detected in Ctenocephalides felis, and Rickettsia sp. IbR/CRC in Ixodes boliviensis. Results demonstrate that dogs from the main urban center of Costa Rica have been exposed to SFG rickettsiae, especially in areas with known human infection. Both human and animal health sectors must be aware of possible rickettsial diseases in urban areas, where dogs may also serve as sentinels for human infection.

  9. Multimethylation of Rickettsia OmpB Catalyzed by Lysine Methyltransferases*

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  11. Ticks and spotted fever group rickettsiae of southeastern Virginia.

    PubMed

    Nadolny, Robyn M; Wright, Chelsea L; Sonenshine, Daniel E; Hynes, Wayne L; Gaff, Holly D

    2014-02-01

    The incidence of tick-borne rickettsial disease in the southeastern United States has been rising steadily through the past decade, and the range expansions of tick species and tick-borne infectious agents, new and old, has resulted in an unprecedented mix of vectors and pathogens. The results of an ongoing 4-year surveillance project describe the relative abundance of questing tick populations in southeastern Virginia. Since 2009, more than 66,000 questing ticks of 7 species have been collected from vegetation in a variety of habitats, with Amblyomma americanum constituting over 95% of ticks collected. Other species represented included Ixodes scapularis, Dermacentor variabilis, Amblyomma maculatum, Ixodes affinis, Haemaphysalis leporispalustris, and Ixodes brunneus. We found that 26.9-54.9% of A. americanum ticks tested were positive for Rickettsia amblyommii, a non-pathogenic symbiont of this tick species. We also found no evidence of R. rickettsii in D. variabilis ticks, although they did show low infection rates of R. montanensis (1.5-2.0%). Rickettsia parkeri and Candidatus R. andeanae were found in 41.8-55.7% and 0-1.5% A. maculatum ticks, respectively. The rate of R. parkeri in A. maculatum ticks is among the highest in the literature and has increased in the 2 years since R. parkeri and A. maculatum were first reported in southeastern Virginia. We conclude that tick populations in southeastern Virginia have recently undergone dramatic changes in species and abundance and that these populations support a variety of rickettsial agents with the potential for increased risk to human health.

  12. Molecular detection of Rickettsia, Borrelia, and Babesia species in Ixodes ricinus sampled in northeastern, central, and insular areas of Italy.

    PubMed

    Castro, Lyda R; Gabrielli, Simona; Iori, Albertina; Cancrini, Gabriella

    2015-07-01

    The aim of the present study was to provide insight into the diversity of tick-borne pathogens circulating in Italy, carried/transmitted by Ixodes ricinus, one of the most abundant tick species in the country. A total of 447 specimens sampled in five areas of northeastern, central and insular Italy were analysed by polymerase chain reaction and sequencing for the presence of rickettsiae, borreliae and babesiae. Several rickettsial species of the spotted fever group of zoonotic concern and other zoonotic pathogens were found, such as Borrelia burgdorferi s.s., Borrelia afzelii, Borrelia garinii, and Babesia venatorum. These findings confirm a wide distribution of tick-borne bacterial and protozoan species in Italy, and highlight the sanitary importance of I. ricinus, often recorded as feeding on humans.

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

    PubMed Central

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

    2016-01-01

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

  14. Nuclear Magnetic Resonance (NMR) as a tool for the study of the metabolism of Rickettsia slovaca.

    PubMed

    García-Álvarez, Lara; Busto, Jesús H; Peregrina, Jesús M; Santibáñez, Sonia; Portillo, Aránzazu; Avenoza, Alberto; Oteo, José A

    2015-01-01

    Rickettsial infections are caused by intracellular bacteria. They do not grow in standard culture media so there are limitations in routine practice to study their metabolism. Nuclear Magnetic Resonance (NMR) spectroscopy is used for identification of metabolites in biological samples. Vero cells infected with Rickettsia slovaca as well as uninfected cells were monitored by (1)H NMR showing the presence of ethanol and lactic acid. As no differences were observed, labeled compounds were added into cultures. When D-[1-13C]glucose was monitored by (13)C NMR no differences among infected and uninfected cells were observed in metabolic profiles. Glucose was transformed into ethanol in all cultures. Monitored experiments carried out with [2-13C]glycine showed differences between infected and uninfected cell cultures spectra. Glycine was partially transformed into serine, but the amount of the serine formed was larger in those infected. Moreover, L-[2-13C]leucine, L-[1-13C]isoleucine and L-[15N]tyrosine were evaluated. No differences among infected and uninfected cells were observed in the metabolic profiles when tyrosine and leucine were monitored. The amino acid L-[1-13C]isoleucine exhibited different metabolism in presence of the R. slovaca, showing a promising behavior as biomarker. In this work we focused on finding one or more compounds that could be metabolized specifically by R. slovaca and could be used as an indicator of its activity.

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

    PubMed Central

    2013-01-01

    Background 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- tRNAfMet, mppA-pruC) sequencing. Methods 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- tRNAfMet and mppA-purC). Results 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. Conclusions New Rickettsia spotted fever strain genotypes were found in Tunisia. Isolates detected in humans and vectors were genetically homogenous despite location differences in their

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

    PubMed

    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).

  17. High prevalence of “Candidatus Rickettsia andeanae” and apparent exclusion of Rickettsia parkeri in adult Amblyomma maculatum (Acari: Ixodidae) from Kansas and Oklahoma

    PubMed Central

    Paddock, Christopher D.; Denison, Amy M.; Dryden, Michael W.; Noden, Bruce H.; Lash, R. Ryan; Abdelghani, Sarah S.; Evans, Anna E.; Kelly, Aubree R.; Hecht, Joy A.; Karpathy, Sandor E.; Ganta, Roman R.; Little, Susan E.

    2015-01-01

    Amblyomma maculatum (the Gulf Coast tick), an aggressive, human-biting, Nearctic and Neotropical tick, is the principal vector of Rickettsia parkeri in the United States. This pathogenic spotted fever group Rickettsia species has been identified in 8–52% of questing adult Gulf Coast ticks in the southeastern United States. To our knowledge, R. parkeri has not been reported previously from adult specimens of A. maculatum collected in Kansas or Oklahoma. A total of 216 adult A. maculatum ticks were collected from 18 counties in Kansas and Oklahoma during 2011–2014 and evaluated by molecular methods for evidence of infection with R. parkeri. No infections with this agent were identified; however, 47% of 94 ticks collected from Kansas and 73% of 122 ticks from Oklahoma were infected with “Candidatus Rickettsia andeanae” a spotted fever group Rickettsia species of undetermined pathogenicity. These preliminary data suggest that “Ca. R. andeanae” is well-adapted to survival in populations of A. maculatum in Kansas and Oklahoma, and that its ubiquity in Gulf Coast ticks in these states may effectively exclude R. parkeri from their shared arthropod host, which could diminish markedly or preclude entirely the occurrence of R. parkeri rickettsiosis in this region of the United States. PMID:25773931

  18. High prevalence of "Candidatus Rickettsia andeanae" and apparent exclusion of Rickettsia parkeri in adult Amblyomma maculatum (Acari: Ixodidae) from Kansas and Oklahoma.

    PubMed

    Paddock, Christopher D; Denison, Amy M; Dryden, Michael W; Noden, Bruce H; Lash, R Ryan; Abdelghani, Sarah S; Evans, Anna E; Kelly, Aubree R; Hecht, Joy A; Karpathy, Sandor E; Ganta, Roman R; Little, Susan E

    2015-04-01

    Amblyomma maculatum (the Gulf Coast tick), an aggressive, human-biting, Nearctic and Neotropical tick, is the principal vector of Rickettsia parkeri in the United States. This pathogenic spotted fever group Rickettsia species has been identified in 8-52% of questing adult Gulf Coast ticks in the southeastern United States. To our knowledge, R. parkeri has not been reported previously from adult specimens of A. maculatum collected in Kansas or Oklahoma. A total of 216 adult A. maculatum ticks were collected from 18 counties in Kansas and Oklahoma during 2011-2014 and evaluated by molecular methods for evidence of infection with R. parkeri. No infections with this agent were identified; however, 47% of 94 ticks collected from Kansas and 73% of 122 ticks from Oklahoma were infected with "Candidatus Rickettsia andeanae" a spotted fever group Rickettsia species of undetermined pathogenicity. These preliminary data suggest that "Ca. R. andeanae" is well-adapted to survival in populations of A. maculatum in Kansas and Oklahoma, and that its ubiquity in Gulf Coast ticks in these states may effectively exclude R. parkeri from their shared arthropod host, which could diminish markedly or preclude entirely the occurrence of R. parkeri rickettsiosis in this region of the United States. Published by Elsevier GmbH.

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

    DTIC Science & Technology

    2013-03-31

    M.E. (2008) Rickettsia parkeri rickettsiosis and its clinical distinction from Rocky Mountain spotted fever . Clinical Infectious Diseases, 47...collected specimens for the presence of Rickettsia parkeri, the causative agent of Tidewater spotted fever in humans (Jiang et al. 2012). The collection

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

    PubMed

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

    2008-07-01

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

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

    PubMed Central

    Hunter, Martha S.; Baltrus, David A.

    2014-01-01

    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. PMID:25217020

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

    PubMed

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

    2008-10-01

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

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

    PubMed

    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.

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

    PubMed

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

    2013-06-01

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

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

    SciTech Connect

    Carl, M.; Dasch, G.A.

    1986-03-01

    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/sup 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.

  6. Rickettsia lusitaniae associated with Ornithodoros yumatensis (Acari: Argasidae) from two caves in Yucatan, Mexico.

    PubMed

    Sánchez-Montes, Sokani; Guzmán-Cornejo, Carmen; Martínez-Nájera, Yecenia; Becker, Ingeborg; Venzal, José M; Labruna, Marcelo B

    2016-10-01

    The genus Rickettsia includes obligate intracellular bacteria transmitted by several hematophagous arthropods such as ticks, fleas and sucking lice. In particular hard ticks (Ixodidae) have been cited as the main vectors of pathogenic rickettsiae in Mexico. However, there have been only two records of a single Rickettsia species associated with Mexican soft ticks (Argasidae). In this study, we searched for rickettsial DNA in argasid ticks (13 adults and eight nymphs of Ornithodoros yumatensis) from two bat caves in the state of Yucatan, Mexico. Additionally one larva collected in a cave from Chiapas, Mexico, and associated with Desmodus rotundus was used to corroborate the tick taxonomic determination. Of these, nine ticks (43%) yielded expected PCR products for the rickettsial gltA gene. These PCR-positive ticks were tested with additional PCR protocols targeting the rickettsial genes gltA, ompA and ompB. DNA partial sequences from these genes showed 99-100% identities with Rickettsia lusitaniae, an agent isolated from O. erraticus in Portugal, and closely related to R. felis and R. hoogstraalii. Based on the results from this study, the inventory of rickettsiae distributed in Mexico increases from six to seven species.

  7. Molecular evidence for a spotted fever group Rickettsia species in the tick Amblyomma longirostre in Brazil.

    PubMed

    Labruna, Marcelo B; McBride, Jere W; Bouyer, Donal H; Camargo, Luis Marcelo A; Camargo, Erney P; Walker, David H

    2004-05-01

    Two Amblyomma longirostre adult male ticks were collected from a Brazilian porcupine Coendou prehensilis L. in the state of Rondonia, Western Amazon, Brazil. The two ticks were pooled for DNA extraction and tested for the presence of rickettsial DNA by amplifying portions of the gltA, 17-kDa, ompA, and ompB rickettsial genes by polymerase chain reaction (PCR). Portions of the four genes were amplified from the sample and subsequently sequenced. These results indicated the presence of a Rickettsia strain infecting A. longirostre, which was designated as strain Aranha. Compared with homologous ompA rickettsial sequences, "Rickettsia amblyommii" ompA seemed to be the closest relative to Aranha (similarity values: 99.0-99.3%). Phylogenetic analyses of more conserved genes including 17-kDa and gtlA partial sequences indicated that this Rickettsia sp. is a spotted fever group rickettsia. The partial ompB sequence of strain Aranha was distinct from all homologous sequences available in GenBank. Although our ompA analysis suggested a very close molecular phylogenetic relationship of Aranha with "R. amblyommii," we cannot at this time determine if Aranha is a new strain of "R. amblyommii" or a new Rickettsia species in South America.

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

    PubMed

    Márquez, Francisco J

    2008-08-01

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

  9. Detection of spotted fever group Rickettsiae in ticks from Zhejiang Province, China.

    PubMed

    Sun, Jimin; Lin, Junfen; Gong, Zhenyu; Chang, Yue; Ye, Xiaodong; Gu, Shiping; Pang, Weilong; Wang, Chengwei; Zheng, Xiaohua; Hou, Juan; Ling, Feng; Shi, Xuguang; Jiang, Jianmin; Chen, Zhiping; Lv, Huakun; Chai, Chengliang

    2015-03-01

    Tick species distribution and prevalence of spotted fever group Rickettsiae (SFGR) in ticks were investigated in Zhejiang Province, China in 2010 and 2011. PCR was used to detect SFGR and positive amplicons were sequenced, compared to published sequences and phylogenic analysis was performed using MEGA 4.0. A total of 292 adult ticks of ten species were captured and 7.5 % (22/292) of the ticks were PCR-positive for SFG Rickettsia. The PCR-positive rates were 5.5 % (6/110) for Haemaphysalis longicornis, 3.6 % (1/28) for Amblyomma testudinarium and 16 % (15/94) for Ixodes sinensis, respectively. Phylogenetic analyses of gltA genes detected in ticks indicated that there are two dominating groups of SFGR. Sequences of group one were closely related to Rickettsia monacensis, whereas sequences of group two were closest related to Rickettsia heilongjiangensis and Rickettsia japonica, which are human pathogens. Our findings underline the importance of these ticks in public health surveillance in Zhejiang Province, China.

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

    PubMed

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

    2014-08-01

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

  11. Borrelia burgdorferi DNA absent, multiple Rickettsia spp. DNA present in ticks collected from a teaching forest in North Central Florida.

    PubMed

    Sayler, Katherine; Rowland, Jessica; Boyce, Carisa; Weeks, Emma

    2017-01-01

    Tick-borne diseases are an emerging public health threat in the United States. In Florida, there has been public attention directed towards the possibility of locally acquired Borrelia burgdorferi sensu stricto, the causative agent of Lyme disease, in association with the lone star tick. The aim of this study was to determine the prevalence of ticks and the pathogens they carry and potentially transmit, such as B. burgdorferi, in a highly utilized teaching and research forest in North Central Florida. Ticks were collected by dragging and flagging methods over a four month period in early 2014, identified, and tested by PCR for multiple pathogens including Anaplasma, Borrelia, Rickettsia, and Ehrlichia species. During the study period the following ticks were collected: 2506 (96.5%) Amblyomma americanum L., 64 (2.5%) Ixodes scapularis Say, 19 (0.7%) Dermacentor variabilis Say, and 5 (0.2%) Ixodes affinis Neuman. Neither Borrelia spp. (0/846) nor Anaplasma spp. (0/69; Ixodes spp. only) were detected by PCR in any of the ticks tested. However, Rickettsia DNA was present in 53.7% (86/160), 62.5% (40/64), 60.0% (3/5) and 31.6% (6/19) of A. americanum, I. scapularis, I. affinis and D. variabilis, respectively. Furthermore, E. chaffeensis and E. ewingii DNA were detected in 1.3% and 4.4% of adult A. americanum specimens tested, respectively. Although receiving an A. americanum bite is likely in wooded areas in North Central Florida due to the abundance of this tick, the risk of contracting a tick-borne pathogen in this specific area during the spring season appears to be low. The potential for pathogen prevalence to be highly variable exists, even within a single geographical site and longitudinal studies are needed to assess how tick-borne pathogen prevalence is changing over time in North Central Florida.

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

    PubMed

    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.

  13. Spotted fever group rickettsiae in Amblyomma ticks likely to infest humans in rural areas from northwestern Argentina.

    PubMed

    Saracho Bottero, María N; Tarragona, Evelina L; Nava, Santiago

    2015-01-01

    This work was performed to detect Rickettsia species of the spotted fever group in Amblyomma ticks likely to infest humans in rural areas from northwestern Argentina. Free-living ticks were collected and determined as Amblyomma tigrinum, Amblyomma neumanni and Amblyomma tonelliae. Rickettsia infection was determined by polymerase chain reactions which amplify fragments of the rickettsial genes gltA and ompA. A high frequency (35/44, 79.5%) of Candidatus "Rickettsia andeanae" was observed in A. tigrinum ticks, and Candidatus "Rickettsia amblyommii" was found in three out of 14 nymphs of A. neumanni. All 14 Amblyomma tonelliae ticks were negative for rikettsiae. The infection with spotted fever group rickettsiae in ticks aggressive for humans reveals the potential risk of exposure to tick-borne pathogens of people inhabiting rural areas of northwestern Argentina.

  14. Detection of rickettsiae in fleas and ticks from areas of Costa Rica with history of spotted fever group rickettsioses.

    PubMed

    Troyo, Adriana; Moreira-Soto, Rolando D; Calderon-Arguedas, Ólger; Mata-Somarribas, Carlos; Ortiz-Tello, Jusara; Barbieri, Amália R M; Avendaño, Adrián; Vargas-Castro, Luis E; Labruna, Marcelo B; Hun, Laya; Taylor, Lizeth

    2016-10-01

    Outbreaks of spotted fevers have been reported in Costa Rica since the 1950s, although vectors responsible for transmission to humans have not been directly identified. In this study, species of Rickettsia were detected in ectoparasites from Costa Rica, mostly from five study sites where cases of spotted fevers have been reported. Ticks and fleas were collected using drag cloths or directly from domestic and wild animals and pooled according to species, host, and location. Pools were analyzed initially by PCR to detect a fragment of Rickettsia spp. specific gltA gene, and those positive were confirmed by detection of htrA and/or ompA gene fragments. Partial sequences of the gltA gene were obtained, as well as at least one ompA and/or ompB partial sequence of each species. Rickettsia spp. were confirmed in 119 of 497 (23.9%) pools of ticks and fleas analyzed. Rickettsia rickettsii was identified in one nymph of Amblyomma mixtum and one nymph of Amblyomma varium. Other rickettsiae present were 'Candidatus Rickettsia amblyommii' in A. mixtum, Amblyomma ovale, Dermacentor nitens, and Rhipicephalus sanguineus s. l.; Rickettsia bellii in Amblyomma sabanerae; Rickettsia felis in Ctenocephalides felis; and Rickettsia sp. similar to 'Candidatus R. asemboensis' in C. felis, Pulex simulans, A. ovale, and Rhipicephalus microplus. Results show the presence of rickettsiae in vectors that may be responsible for transmission to humans in Costa Rica, and evidence suggests exposure to rickettsial organisms in the human environment may be common. This is the first study to report R. rickettsii in A. varium and in A. mixtum in Costa Rica.

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

    PubMed Central

    Ereqat, Suheir; Nasereddin, Abedelmajeed; Al-Jawabreh, Amer; Azmi, Kifaya; Harrus, Shimon; Mumcuoglu, Kosta; Apanaskevich, Dimtry; Abdeen, Ziad

    2016-01-01

    Background 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. Methodology/Principal Findings 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. Significance 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

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

    PubMed

    Ereqat, Suheir; Nasereddin, Abedelmajeed; Al-Jawabreh, Amer; Azmi, Kifaya; Harrus, Shimon; Mumcuoglu, Kosta; Apanaskevich, Dimtry; Abdeen, Ziad

    2016-01-01

    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.

  17. Common epidemiology of Rickettsia felis infection and malaria, Africa.

    PubMed

    Mediannikov, Oleg; Socolovschi, Cristina; Edouard, Sophie; Fenollar, Florence; Mouffok, Nadjet; Bassene, Hubert; Diatta, Georges; Tall, Adama; Niangaly, Hamidou; Doumbo, Ogobara; Lekana-Douki, Jean Bernard; Znazen, Abir; Sarih, M'hammed; Ratmanov, Pavel; Richet, Herve; Ndiath, Mamadou O; Sokhna, Cheikh; Parola, Philippe; Raoult, Didier

    2013-11-01

    This study aimed to compare the epidemiology of Rickettsia felis infection and malaria in France, North Africa, and sub-Saharan Africa and to identify a common vector. Blood specimens from 3,122 febrile patients and from 500 nonfebrile persons were analyzed for R. felis and Plasmodium spp. We observed a significant linear trend (p<0.0001) of increasing risk for R. felis infection. The risks were lowest in France, Tunisia, and Algeria (1%), and highest in rural Senegal (15%). Co-infections with R. felis and Plasmodium spp. and occurrences of R. felis relapses or reinfections were identified. This study demonstrates a correlation between malaria and R. felis infection regarding geographic distribution, seasonality, asymptomatic infections, and a potential vector. R. felis infection should be suspected in these geographical areas where malaria is endemic. Doxycycline chemoprophylaxis against malaria in travelers to sub-Saharan Africa also protects against rickettsioses; thus, empirical treatment strategies for febrile illness for travelers and residents in sub-Saharan Africa may require reevaluation.

  18. Molecular detection of Rickettsia amblyommii in Amblyomma americanum parasitizing humans.

    PubMed

    Jiang, Ju; Yarina, Tamasin; Miller, Melissa K; Stromdahl, Ellen Y; Richards, Allen L

    2010-05-01

    A quantitative real-time polymerase chain reaction assay to detect and quantify a portion of the outer membrane protein B gene (ompB) of Rickettsia amblyommii was employed to assess the threat of R. amblyommii exposure to humans parasitized by Amblyomma americanum (the lone star tick). A total of 72 pools of lone star ticks removed from humans were acquired from two collections and used in this study: 44 pools of A. americanum submitted to the Department of Defense Human Tick Test Kit Program in 2003 collected from 220 individuals from 14 states, and 28 pools of A. americanum representing 120 ticks obtained from boy scouts and adult leaders at the Boy Scouts of America National Jamboree held at Fort A.P. Hill, Virginia, in 2005. Of the 72 lone star tick pools representing 340 lone star ticks, 58 pools (80.5%) were positive for R. amblyommii. In addition, individual A. americanum ticks parasitizing humans collected as part of the Department of Defense Human Tick Test Kit Program in 2002 and 2003 from 17 states were evaluated. It was found that 244 of 367 (66.5%) individual A. americanum ticks tested positive for the presence of R. amblyommii DNA. These results clearly show that lone star ticks parasitizing humans are highly infected with R. amblyommii, which may potentiate rickettsial infection of and possibly disease in humans.

  19. mariner-Based Transposon Mutagenesis of Rickettsia prowazekii▿ †

    PubMed Central

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

    2007-01-01

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

  20. Transmission potential of Rickettsia felis infection by Anopheles gambiae mosquitoes

    PubMed Central

    Dieme, Constentin; Bechah, Yassina; Socolovschi, Cristina; Audoly, Gilles; Berenger, Jean-Michel; Faye, Ousmane; Raoult, Didier; Parola, Philippe

    2015-01-01

    A growing number of recent reports have implicated Rickettsia felis as a human pathogen, paralleling the increasing detection of R. felis in arthropod hosts across the globe, primarily in fleas. Here Anopheles gambiae mosquitoes, the primary malarial vectors in sub-Saharan Africa, were fed with either blood meal infected with R. felis or infected cellular media administered in membrane feeding systems. In addition, a group of mosquitoes was fed on R. felis-infected BALB/c mice. The acquisition and persistence of R. felis in mosquitoes was demonstrated by quantitative PCR detection of the bacteria up to day 15 postinfection. R. felis was detected in mosquito feces up to day 14. Furthermore, R. felis was visualized by immunofluorescence in salivary glands, in and around the gut, and in the ovaries, although no vertical transmission was observed. R. felis was also found in the cotton used for sucrose feeding after the mosquitoes were fed infected blood. Natural bites from R. felis-infected An. gambiae were able to cause transient rickettsemias in mice, indicating that this mosquito species has the potential to be a vector of R. felis infection. This is particularly important given the recent report of high prevalence of R. felis infection in patients with “fever of unknown origin” in malaria-endemic areas. PMID:26056256

  1. Common Epidemiology of Rickettsia felis Infection and Malaria, Africa

    PubMed Central

    Mediannikov, Oleg; Socolovschi, Cristina; Edouard, Sophie; Fenollar, Florence; Mouffok, Nadjet; Bassene, Hubert; Diatta, Georges; Tall, Adama; Niangaly, Hamidou; Doumbo, Ogobara; Lekana-Douki, Jean Bernard; Znazen, Abir; Sarih, M’hammed; Ratmanov, Pavel; Richet, Herve; Ndiath, Mamadou O.; Sokhna, Cheikh; Parola, Philippe

    2013-01-01

    This study aimed to compare the epidemiology of Rickettsia felis infection and malaria in France, North Africa, and sub-Saharan Africa and to identify a common vector. Blood specimens from 3,122 febrile patients and from 500 nonfebrile persons were analyzed for R. felis and Plasmodium spp. We observed a significant linear trend (p<0.0001) of increasing risk for R. felis infection. The risks were lowest in France, Tunisia, and Algeria (1%), and highest in rural Senegal (15%). Co-infections with R. felis and Plasmodium spp. and occurrences of R. felis relapses or reinfections were identified. This study demonstrates a correlation between malaria and R. felis infection regarding geographic distribution, seasonality, asymptomatic infections, and a potential vector. R. felis infection should be suspected in these geographical areas where malaria is endemic. Doxycycline chemoprophylaxis against malaria in travelers to sub-Saharan Africa also protects against rickettsioses; thus, empirical treatment strategies for febrile illness for travelers and residents in sub-Saharan Africa may require reevaluation. PMID:24188709

  2. Rickettsia, Ehrlichia, Anaplasma, and Bartonella in ticks and fleas from dogs and cats in Bangkok.

    PubMed

    Foongladda, Suporn; Inthawong, Dutsadee; Kositanont, Uraiwan; Gaywee, Jariyanart

    2011-10-01

    Flea and tick specimens (5-10 fleas or ticks) on dogs and cats from various sites in Bangkok were tested by polymerase chain reaction and DNA sequencing to detect DNA of bacteria Rickettsia (gltA and 17 kDa genes), Anaplasmataceae (16S rRNA gene), and Bartonella (pap31 and its genes). We confirmed that Rickettsia sp. related to Rickettsia felis was detected in 66 of 98 (67.4%) flea specimens from dogs, whereas 8 Bartonella henselae and 2 Bartonella clarridgeiae were detected in 10 of 54 (18.5%) flea specimens from cats. Further, this work provides the first evidence of 10 Ehrlichia canis (3.3%), 7 Anaplasma platys (2.3%), and 2 Wolbachia spp. (0.66%) in 304 Rhipicephalus sanguineus tick specimens in Thailand.

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

    PubMed

    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.

  4. [Microbiological diagnosis of emerging bacterial pathogens: Anaplasma, Bartonella, Rickettsia, and Tropheryma whipplei].

    PubMed

    Blanco, José Ramón; Jado, Isabel; Marín, Mercedes; Sanfeliu, Isabel; Portillo, Aránzazu; Anda, Pedro; Pons, Immaculada; Oteo, José Antonio

    2008-11-01

    Ehrlichia/Anaplasma, Bartonella, Rickettsia and Tropheryma whipplei (formerly called whippelii) are fastidious bacterial organisms, considered the causative agents of potentially severe emerging and re-emerging diseases with repercussions on public health. The recent availability of advanced molecular biology and cell culture techniques has led to the implication of many of these species in human pathologies. These issues are extensively covered in number 27 of the SEIMC microbiological procedure: Diagnóstico microbiológico de las infecciones por patógenos bacterianos emergentes: Anaplasma, Bartonella, Rickettsia y Tropheryma whippelii (Microbiological diagnosis of Anaplasma, Bartonella, Rickettsia and Tropheryma whippelii infections) (2nd ed., 2007) (www.seimc.org/documentos/protocolos/microbiologia/).

  5. Identification of Rickettsia conorii infection by polymerase chain reaction in a soldier returning from Somalia.

    PubMed

    Williams, W J; Radulovic, S; Dasch, G A; Lindstrom, J; Kelly, D J; Oster, C N; Walker, D H

    1994-07-01

    A soldier developed characteristic manifestations of boutonneuse fever shortly after leaving Somalia. Rickettsial DNA was detected in a biopsy sample of the tache noire by a polymerase chain reaction (PCR) in which primers derived from the 190-kD antigen gene of Rickettsia rickettsii were used. The source of this DNA was identified as Rickettsia conorii by restriction fragment length polymorphism (RFLP) analysis of the PCR product. R. conorii was also isolated from the skin biopsy specimen. The patient did not develop a significant increase in specific antibodies, as assessed by indirect fluorescent antibody testing, until several weeks after the onset of symptoms. This case demonstrates that the PCR/RFLP technique can be used for the direct identification of rickettsiae from clinical specimens. To our knowledge, this is the first confirmed case of R. conorii infection in Somalia.

  6. Infectious Diseases in Wild Animals in Utah VI. Experimental Infection of Birds with Rickettsia rickettsii

    PubMed Central

    Lundgren, D. L.; Thorpe, B. D.; Haskell, C. D.

    1966-01-01

    Lundgren, D. L. (University of Utah, Salt Lake City), B. D. Thorpe, and C. D. Haskell. Infectious diseases in wild animals in Utah. VI. Experimental infection of birds with Rickettsia rickettsii. J. Bacteriol. 91:963–966. 1966.—Chickens, pigeons, pheasants, sparrow hawks, red-tailed hawks, ravens, magpies, and a marsh hawk were inoculated with Rickettsia rickettsii, the etiological agent of Rocky Mountain spotted fever. The development and persistence of complement-fixing (CF) antibodies and rickettsemias were tested for in these birds. Rickettsiae were recovered from the blood of a number of birds up to the 16th day after inoculation, whereas only the pigeon was found to develop high CF antibody titers. It was concluded that certain species of birds have the potential of contributing to the dissemination of R. rickettsii in nature, and that the CF test is generally unsuitable for serological diagnosis of this organism in birds. PMID:4956338

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

    PubMed

    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.

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

    PubMed Central

    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

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

    PubMed Central

    Cowdry, E. V.

    1923-01-01

    In the absence of a satisfactory definition of Rickettsia the observations herein recorded were arbitrarily limited to bacterium-like organisms which are intracellular and Gram-negative. Rickettsia of this type were found in the following species: Amblyomma americana, Amblyomma hebræum, Boophilus 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: Attidæ, Trombidiidæ, Argasidæ, lxodidæ, Cinura, Acanthiidæ, Pediculidæ, Hippoboscidæ, Chrysopidæ, Pulicidæ, and Ichneumonidæ. 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. PMID:19868737

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

    PubMed

    Alberdi, M Pilar; Nijhof, Ard M; Jongejan, Frans; Bell-Sakyi, Lesley

    2012-12-01

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

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

    PubMed Central

    Turco, Jenifer; Winkler, Herbert H.

    1982-01-01

    The growth of avirulent (E) and virulent (Breinl) strains of Rickettsia prowazekii was compared in four mouse macrophage-like cell lines (RAW264.7, J774.1, P388D1, and PU5), one human macrophage-like cell line (U937-1), and the mouse fibroblast line L929. The E and Breinl strains grew equally well in L929 cells. However, all of the mouse macrophage-like cell lines clearly differentiated between the two strains by restricting the growth of the E strain relative to that of the Breinl strain. A nonuniform response to infection was sometimes observed in which E strain rickettsiae were cleared from the majority of the infected cells, but multiplied in some of the remaining infected cells. The human line U937-1 was not very effective at differentiating the E and Breinl strains. Addition of rabbit antirickettsial antiserum to the Breinl or E strains of R. prowazekii immediately before infection of L929 cells caused a marked decrease in the initial infection but had no effect on the subsequent growth of the rickettsiae in the L929 cells. In contrast, addition of antiserum to Breinl or E strain rickettsiae immediately before infection of macrophage-like cell lines caused either no change or an increase in the initial infection. Most of the rickettsiae that infected the mouse macrophage-like cell lines in the presence of antiserum were destroyed in these cell lines. Thus, when the infection took place in the presence of antiserum, the mouse macrophage-like cell lines no longer differentiated between the E and Breinl strains. These data indicate that mouse macrophage-like cell lines should be a useful model system for defining the differences between the E and Breinl strains of Rickettsia prowazekii, differences which should lead to an understanding of the biochemical basis of virulence in this organism. PMID:6802758

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

    PubMed Central

    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

  13. Carrying Backpacks: Physical Effects

    ERIC Educational Resources Information Center

    Illinois State Board of Education, 2006

    2006-01-01

    It is estimated that more than 40 million U.S. youth carry school materials in backs, routinely carrying books, laptop computers, personal and other items used on a daily basis. The Consumer Product Safety Commission (CPSC) estimates that 7,277 emergency visits each year result from injuries related to backpacks. Injury can occur when a child…

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

    PubMed

    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.

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

    PubMed

    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.

  16. Survey for Hantaviruses, Tick-Borne Encephalitis Virus, and Rickettsia spp. in Small Rodents in Croatia

    PubMed Central

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

    2014-01-01

    Abstract 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 immunoflourescence 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. PMID:24866325

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

    PubMed

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

    2014-10-01

    Our goal was to understand rickettsial spotted fevers' circulation in areas of previous outbreaks reported from 2006 to 2008 in Colombia. We herein present molecular identification and isolation of Rickettsia sp. Atlantic rainforest strain from Amblyomma ovale ticks, a strain shown to be pathogenic to humans. Infected ticks were found on dogs and a rodent in Antioquia and Córdoba Provinces. This is the first report of this rickettsia outside Brazil, which expands its known range considerably. Copyright © 2014 Elsevier GmbH. All rights reserved.

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

    PubMed Central

    Smith, Joshua D.; Zawada, Sonya E.; Arias, Jorge R.; Norris, Douglas E.

    2013-01-01

    Abstract We report the first evidence of Rickettsia massiliae in the brown dog tick, Rhipicephalus sanguineus, from the East Coast of the United States. As part of routine pathogen surveillance, DNA samples from ixodid ticks were tested for spotted fever group rickettsiae by nested PCR. A R. massiliae-positive tick was collected off a beagle mix recently rescued from North Carolina. Infection was confirmed by partial sequence analysis of the htrA, gltA, ompB, ompA, and sca4 genes, which had 100% identity to a R. massiliae isolate from Arizona. PMID:23199270

  19. Viral association with the elusive rickettsia of viper plague from Ghana, West Africa.

    PubMed

    Kiel, Johnathan L; Gonzalez, Yvette; Parker, Jill E; Andrews, Carrie; Martinez, Dominique; Vachiéry, Nathalie; Lefrançois, Thierry

    2008-12-01

    We previously reported a rickettsial heartwater-like disease in vipers from Ghana that resembled heartwater in its gross lesions, was apparently transmitted by ticks (Aponomma and Amblyomma), and responded clinically favorably to early treatment with tetracycline. Cell culture showed consistent cytopathic effects in bovine endothelial cells, viper cells, and mouse cells, and inhibition of cytopathic effect by tetracycline in vitro. A type D retrovirus was observed in vacuoles in all infected cells. The virus and rickettsia infection was associated with transfer of cytopathic effect, regardless of cell species. Close association of virus and rickettsia may indicate a dual infection etiology of viper plague.

  20. Rickettsia amblyommii infecting Amblyomma sculptum in endemic spotted fever area from southeastern Brazil.

    PubMed

    Nunes, Emília de Carvalho; Vizzoni, Vinicius Figueiredo; Navarro, Daniel Leal; Iani, Felipe Campos de Melo; Durães, Liliane Silva; Daemon, Erik; Soares, Carlos Augusto Gomes; Gazeta, Gilberto Salles

    2015-12-01

    The Rickettsia bacteria include the aetiological agents for the human spotted fever (SF) disease. In the present study, a SF group Rickettsia amblyommii related bacterium was detected in a field collected Amblyomma sculptum (Amblyomma cajennense species complex) tick from a Brazilian SF endemic site in southeastern Brazil, in the municipality of Juiz de Fora, state of Minas Gerais. Genetic analysis based on genes ompA,ompB and htrA showed that the detected strain, named R. amblyommii str. JF, is related to the species R. amblyommii.

  1. Rickettsia amblyommii infecting Amblyomma sculptum in endemic spotted fever area from southeastern Brazil

    PubMed Central

    Nunes, Emília de Carvalho; Vizzoni, Vinicius Figueiredo; Navarro, Daniel Leal; Iani, Felipe Campos de Melo; Durães, Liliane Silva; Daemon, Erik; Soares, Carlos Augusto Gomes; Gazeta, Gilberto Salles

    2015-01-01

    The Rickettsia bacteria include the aetiological agents for the human spotted fever (SF) disease. In the present study, a SF groupRickettsia amblyommii related bacterium was detected in a field collected Amblyomma sculptum (Amblyomma cajennense species complex) tick from a Brazilian SF endemic site in southeastern Brazil, in the municipality of Juiz de Fora, state of Minas Gerais. Genetic analysis based on genes ompA,ompB and htrA showed that the detected strain, named R. amblyommii str. JF, is related to the speciesR. amblyommii. PMID:26676317

  2. Detection and identification of a novel spotted fever group rickettsia in Western Australia.

    PubMed

    Owen, Helen; Unsworth, Nathan; Stenos, John; Robertson, Ian; Clark, Phillip; Fenwick, Stan

    2006-10-01

    The extent to which rickettsiae are present in Western Australia (WA) is largely unknown. Recently there has been anecdotal evidence of a disease of unknown but possibly rickettsial origin occurring on Barrow Island, WA. Ticks were collected from people and screened using PCR. The rickettsial species was then cultured and its novelty and phylogenetic position examined. The infecting rickettsial species is divergent enough to be classified as a novel species. Sequence data suggest that the evolutionary route for Australian rickettsiae did not progress through a recent common ancestor. The pathogenic potential of the novel species is as yet unknown.

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

    PubMed

    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.

  4. Rickettsia felis in fleas from Catalonia (Northeast Spain).

    PubMed

    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.

  5. Persisting Rickettsia typhi Causes Fatal Central Nervous System Inflammation

    PubMed Central

    Papp, Stefanie; Moderzynski, Kristin; Kuehl, Svenja; Richardt, Ulricke; Fleischer, Bernhard

    2016-01-01

    Rickettsioses are emerging febrile diseases caused by obligate intracellular bacteria belonging to the family Rickettsiaceae. Rickettsia typhi belongs to the typhus group (TG) of this family and is the causative agent of endemic typhus, a disease that can be fatal. In the present study, we analyzed the course of R. typhi infection in C57BL/6 RAG1−/− mice. Although these mice lack adaptive immunity, they developed only mild and temporary symptoms of disease and survived R. typhi infection for a long period of time. To our surprise, 3 to 4 months after infection, C57BL/6 RAG1−/− mice suddenly developed lethal neurological disorders. Analysis of these mice at the time of death revealed high bacterial loads, predominantly in the brain. This was accompanied by a massive expansion of microglia and by neuronal cell death. Furthermore, high numbers of infiltrating CD11b+ macrophages were detectable in the brain. In contrast to the microglia, these cells harbored R. typhi and showed an inflammatory phenotype, as indicated by inducible nitric oxide synthase (iNOS) expression, which was not observed in the periphery. Having shown that R. typhi persists in immunocompromised mice, we finally asked whether the bacteria are also able to persist in resistant C57BL/6 and BALB/c wild-type mice. Indeed, R. typhi could be recultivated from lung, spleen, and brain tissues from both strains even up to 1 year after infection. This is the first report demonstrating persistence and reappearance of R. typhi, mainly restricted to the central nervous system in immunocompromised mice. PMID:26975992

  6. Prevalence of antibodies to spotted fever group rickettsiae in human beings and dogs from and endemic area of mediterranean spotted fever in Catalonia, Spain.

    PubMed

    Segura-Porta, F; Diestre-Ortin, G; Ortuño-Romero, A; Sanfeliu-Sala, I; Font-Creus, B; Muñoz-Espin, T; de Antonio, E M; Casal-Fábrega, J

    1998-06-01

    We assessed the prevalence of antibodies to spotted fever group rickettsiae in human beings and dogs by indirect immunofluorescence in the region of 'Vallés Occidental', Barcelona (Spain). In the group of 150 serum samples from patients without former history of Mediterranean spotted fever, 12 had antibodies to Rickettsia conori. The overall seroprevalence was 8% (95% confidence interval, 4.6% to 13.5%). There were no statistically significant differences between the mean ages of patients with positive and negative antibodies to R. conorii. However, seropositivity was significantly more common among patients living in semi-rural areas. In the group of 138 dog serum samples, 36 (26.1%) sera had antibodies to R. conorii. When the present results were compared with those obtained in a previous seroepidemiological survey carried out in the same geographical region in 1987, no significant differences were found. Therefore, although the epidemiological markers have dropped, this does not absolutely confirm the decrease of the presence of R. conorii in this area.

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

    PubMed

    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.

  8. 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.

    PubMed

    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.

  9. Rickettsial infection in capybaras (Hydrochoerus hydrochaeris) from São Paulo, Brazil: serological evidence for infection by Rickettsia bellii and Rickettsia parkeri.

    PubMed

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

    2007-09-01

    In Brazil, capybaras (Hydrochoerus hydrochaeris) are important hosts for Amblyomma ticks, which in turn can transmit rickettsiae to humans and animals. Therefore, capybaras are potential sentinels for rickettsial infection. The present study evaluated rickettsial infection in capybaras in different areas of the state of São Paulo, where rickettsiosis has never been reported. Materials and methods. Blood sera from 73 capybaras from six localities in São Paulo were tested by indirect immunofluorescence assay using Rickettsia rickettsii, Rickettsia parkeri, and Rickettsia bellii antigens. Capybara spleens were tested by PCR, targeting a fragment of the rickettsial gltA gene. Ticks were collected from each capybara sample and taxonomically identified to species. A total of 94 positively reacting capybara samples, 19 (26.0%), 25 (34.2%), and 50 (68.5%) capybara sera reacted to R. rickettsii, R. parkeri, and R. bellii, respectively. Twenty-five capybara sera showed titers to R. bellii at least four-fold higher than to any of the other two antigens. These sera were considered homologous to R. bellii. Using the same criteria, 3 capybara sera were considered homologous to R. parkeri. No sera were be considered homologous to R. rickettsii. No rickettsial DNA was detected in capybara spleen samples. Ticks collected on capybaras were Amblyomma dubitatum and Amblyomma cajennense. The first evidence is reported of R. bellii natural infection in vertebrate hosts, and the first evidence of R. parkeri infection in capybaras. While R. parkeri is known to infect and cause disease in humans, no similar evidence for human infection has been indicated by R. bellii.

  10. Molecular detection of Rickettsia rhipicephali and other spotted fever group Rickettsia species in Amblyomma ticks infesting wild birds in the state of Minas Gerais, Brazil.

    PubMed

    Zeringóta, Viviane; Maturano, Ralph; Luz, Hermes Ribeiro; Senra, Tatiane Oliveira Souza; Daemon, Erik; Faccini, João Luiz Horacio; McIntosh, Douglas

    2017-01-01

    The current study evaluated parasitism of wild birds by ticks in a fragment of Atlantic Forest in the state of Minas Gerais, Brazil, and examined the ticks for rickettsial agents. Birds were captured during 2014 and 2015 and ticks were identified by sequencing fragments of the 16S and 12S ribosomal DNA. Among 260 birds representing 19 families and 52 species, a total of 69 (26.5%) were found to be infested by larvae (LL) and/or nymphs (NN) of Amblyomma longirostre (Koch, 1844) (45 LL, 4 NN), Amblyomma calcaratum Neumann, 1899 (9 LL, 15 NN), Amblyomma nodosum Neumann, 1899 (2 NN), Amblyomma parkeri Fonseca and Aragão, 1952 (21 LL), Amblyomma sp. haplotype Nazaré (77 LL), and Haemaphysalis leporispalustris (Packard, 1869) (17 LL, 1 NN). The use of PCR and sequencing of the rickettsial genes gltA, htrA, ompA and ompB, revealed the presence of "Candidatus Rickettsia amblyommii" in A. longirostre (13/49; 26%) and Rickettsia parkeri (strain ApPR) in both A. parkeri (1/21; 5%) and haplotype Nazaré (42/77; 55%) ticks. In addition, we detected Rickettsia rhipicephali in 31 (40%) of the 77 haplotype Nazaré ticks. This is the first record of this rickettsial agent in a species of the genus Amblyomma. The pathogenic potential of this bacterium is undetermined, but the unprecedented association with Amblyomma ticks may represent a cause for concern for public and/or animal health.

  11. Prevalence of rickettsia felis-like and Bartonella Spp. in Ctenocephalides felis and Ctenocephalides canis from La Rioja (Northern Spain).

    PubMed

    Blanco, José Ramón; Pérez-Martínez, Laura; Vallejo, Manuel; Santibáñez, Sonia; Portillo, Aránzazu; Oteo, José Antonio

    2006-10-01

    Our aim was to determine the presence of Rickettsia spp. and Bartonella spp. in Ctenocephalides felis and Ctenocephalides canis from La Rioja (Spain). A total of 88 specimens were tested by polymerase chain reaction (PCR) using gltA and ompB genes as targets for Rickettsia spp., and 16S rRNA and ribC genes for Bartonella spp. Rickettsia felis-like (28.4%), Bartonella clarridgeiae (6.8%), and Bartonella henselae (3.4%) were detected in Ctenocephalides spp. Other Bartonella sp. different from B. clarridgeiae and B. henselae could also be present in fleas from La Rioja.

  12. THE ANTIGENIC RELATIONSHIP BETWEEN PROTEUS X-19 AND TYPHUS RICKETTSIA : II. A STUDY OF THE COMMON ANTIGENIC FACTOR.

    PubMed

    Castaneda, M R

    1934-06-30

    A soluble specific substance was isolated from Mexican typhus Rickettsia which gave, with Proteus X-19 antiserum and typhus human serum, the same precipitation reactions as the polysaccharides extracted from B. proteus OX-19. The soluble specific substance extracted from Rickettsia and Proteus OX-19 is likely to be of a polysaccharide nature owing to the strong Molisch reactions obtained with such extracts, the heat stability and the negative protein reactions (biuret). Since, however, it still contains 7 per cent nitrogen, this is not certain. In the antigenic composition of both Proteus X-19 and typhus Rickettsia there is a common soluble specific factor which is responsible for the Weil-Felix reaction.

  13. Prevalence of Rickettsia and Bartonella species in Spanish cats and their fleas.

    PubMed

    Gracia, María Jesús; Marcén, José Miguel; Pinal, Rocio; Calvete, Carlos; Rodes, Daniel

    2015-12-01

    The aim of this study was to determine the prevalence of Bartonella henselae, Rickettsia felis, and Rickettsia typhi in fleas and companion cats (serum and claws) and to assess their presence as a function of host, host habitat, and level of parasitism. Eighty-nine serum and claw samples and 90 flea pools were collected. Cat sera were assayed by IFA for Bartonella henselae and Rickettssia species IgG antibodies. Conventional PCRs were performed on DNA extracted from nails and fleas collected from cats. A large portion (55.8%) of the feline population sampled was exposed to at least one of the three tested vector-borne pathogens. Seroreactivity to B. henselae was found in 50% of the feline studied population, and to R. felis in 16.3%. R. typhi antibodies were not found in any cat. No Bartonella sp. DNA was amplified from the claws. Flea samples from 41 cats (46%) showed molecular evidence for at least one pathogen; our study demonstrated a prevalence rate of 43.3 % of Rickettsia sp and 4.4% of Bartonella sp. in the studied flea population. None of the risk factors studied (cat's features, host habitat, and level of parasitation) was associated with either the serology or the PCR results for Bartonella sp. and Rickettsia sp.. Flea-associated infectious agents are common in cats and fleas and support the recommendation that stringent flea control should be maintained on cats.

  14. Severe Fever with Thrombocytopenia Syndrome Complicated by Co-infection with Spotted Fever Group Rickettsiae, China

    PubMed Central

    Lu, Qing-Bin; Li, Hao; Zhang, Pan-He; Cui, Ning; Yang, Zhen-Dong; Fan, Ya-Di; Cui, Xiao-Ming; Hu, Jian-Gong; Guo, Chen-Tao; Zhang, Xiao-Ai; Cao, Wu-Chun

    2016-01-01

    During 2013–2015 in central China, co-infection with spotted fever group rickettsiae was identified in 77 of 823 patients infected with severe fever with thrombocytopenia syndrome virus. Co-infection resulted in delayed recovery and increased risk for death, prompting clinical practices in the region to consider co-infection in patients with severe fever with thrombocytopenia syndrome. PMID:27767921

  15. Novel Candidatus Rickettsia Species Detected in Nostril Tick from Human, Gabon, 2014

    PubMed Central

    Lopez-Velez, Rogelio; Palomar, Ana M.; Oteo, José A.; Norman, Francesca F.; Pérez-Molina, José A.

    2015-01-01

    We report the identification of a nymphal nostril tick (Amblyomma sp.) from a national park visitor in Gabon and subsequent molecular detection and characterization of tickborne bacteria. Our findings provide evidence of a potentially new Rickettsia sp. circulating in Africa and indicate that tick bites may pose a risk to persons visiting parks in the region. PMID:25625886

  16. Rickettsia parkeri in Amblyomma maculatum Ticks, North Carolina, USA, 2009–2010

    PubMed Central

    Paddock, Christopher D.; Engber, Barry; Toliver, Marcee

    2011-01-01

    We detected Rickettsia parkeri in 20%−33% of Amblyomma maculatum ticks sampled in North Carolina. Results highlight the high frequencies of R. parkeri–infected ticks in the state with the highest annual incidence of Rocky Mountain spotted fever. Epidemiologic studies are needed to definitively link R. parkeri to cases of spotted fever rickettsiosis. PMID:22172164

  17. Host defenses to Rickettsia rickettsii infection contribute to increased microvascular permeability in human cerebral endothelial cells.

    PubMed

    Woods, Michael E; Olano, Juan P

    2008-03-01

    Rickettsiae are arthropod-borne intracellular bacterial pathogens that primarily infect the microvascular endothelium leading to systemic spread of the organisms and the major pathophysiological effect, increased microvascular permeability, and edema in vital organs such as the lung and brain. Much work has been done on mechanisms of immunity to rickettsiae, as well as the responses of endothelial cells to rickettsial invasion. However, to date, no one has described the mechanisms of increased microvascular permeability during acute rickettsiosis. We sought to establish an in vitro model of human endothelial-target rickettsial infection using the etiological agent of Rocky Mountain spotted fever, Rickettsia rickettsii, and human cerebral microvascular endothelial cells. Endothelial cells infected with R. rickettsii exhibited a dose-dependent decrease in trans-endothelial electrical resistance, which translates into increased monolayer permeability. Additionally, we showed that the addition of pro-inflammatory stimuli essential to rickettsial immunity dramatically enhanced this effect. This increase in permeability correlates with dissociation of adherens junctions between endothelial cells and is not dependent on the presence of nitric oxide. Taken together, these results demonstrate for the first time that increased microvascular permeability associated with rickettsial infection is partly attributable to intracellular rickettsiae and partly attributable to the immune defenses that have evolved to protect the host from rickettsial spread.

  18. Susceptibility of inbred mice to rickettsiae of the spotted fever group.

    PubMed Central

    Eisemann, C S; Nypaver, M J; Osterman, J V

    1984-01-01

    A mouse strain susceptible to lethal infection with Rickettsia conorii was required for testing vaccine efficacy and for studying the immunology and pathogenesis of infection. Among 20 strains of inbred mice inoculated intraperitoneally with the Malish strain of R. conorii, the C3H/HeJ mouse strain was the most susceptible, with a 50% lethal dose of approximately 10 PFU. Infection of all mouse strains resulted in a measurable antibody response; the highest titers correlated with the greatest degree of rickettsial replication as measured by plaque assay of infected spleen homogenates. Inoculation of C3H/HeJ mice with 5.0 log10 organisms of strain Malish by the subcutaneous route did not result in lethal infection. The Casablanca and Moroccan strains of R. conorii were not lethal for C3H/HeJ mice and, in addition, produced plaques in L-929 cells morphologically distinct from those produced by the Malish strain. The only other spotted fever group rickettsia tested which produced a lethal infection in C3H/HeJ mice was Rickettsia sibirica. Sublethal infection with any of the spotted fever rickettsiae tested protected against lethal infection with R. conorii. These data established a lethal challenge system for examining the protective efficacy of spotted fever immunogens and presented evidence of biological variation among strains of R. conorii. Images PMID:6418657

  19. Adherence to and Invasion of Host Cells by Spotted Fever Group Rickettsia Species

    PubMed Central

    Chan, Yvonne Gar-Yun; Riley, Sean Phillip; Martinez, Juan Jose

    2010-01-01

    The pathogenic lifecycle of obligate intracellular bacteria presents a superb opportunity to develop understanding of the interaction between the bacteria and host under the pretext that disruption of these processes will likely lead to death of the pathogen and prevention of associated disease. Species of the genus Rickettsia contain some of the most hazardous of the obligate intracellular bacteria, including Rickettsia rickettsii and R. conorii the causative agents of Rocky Mountain and Mediterranean spotted fevers, respectively. Spotted fever group Rickettsia species commonly invade and thrive within cells of the host circulatory system whereby the endothelial cells are severely perturbed. The subsequent disruption of circulatory continuity results in much of the severe morbidity and mortality associated with these diseases, including macropapular dermal rash, interstitial pneumonia, acute renal failure, pulmonary edema, and other multisystem manifestations. This review describes current knowledge of the essential pathogenic processes of adherence to and invasion of host cells, efforts to disrupt these processes, and potential for disease prevention through vaccination with recently identified bacterial adherence and invasion proteins. A more complete understanding of these bacterial proteins will provide an opportunity for prevention and treatment of spotted fever group Rickettsia infections. PMID:21687751

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

    PubMed Central

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

    1992-01-01

    The recent discovery of cat fleas (Ctenocephalides felis) infected with a typhuslike rickettsia (designated the ELB agent) raises the question of whether similar rickettsial infections exist in wild cat flea populations. We verified the presence of the ELB agent and Rickettsia typhi in urban and suburban areas of Los Angeles, Calif. Opossums trapped in close proximity to the residences of human murine typhus cases in Los Angeles county and other areas within the city of Los Angeles were tested for the presence of typhus group rickettsiae by the polymerase chain reaction (PCR). The presence of rickettsiae in the spleen tissues of three opossums (n = 9) and in 66 opossum fleas (n = 205) was determined by PCR and was verified by dot blot and Southern transfer hybridization. Further analysis of the amplified PCR products generated by a series of primer pairs derived from either the 17-kDa antigen gene or the citrate synthase gene revealed that both R. typhi and the ELB agent were present in the tested samples. Dual infection was not noted in the samples; however, the fleas were infected with either R. typhi or the ELB agent. The presence of the ELB agent in the cat flea population may have implications for public health. Whether this agent is responsible for the mild cases of human murine typhus in urban and suburban areas of Los Angeles or in other endemic foci remains to be determined. Images PMID:1629332

  1. Detection of Rickettsia spp in Ticks by MALDI-TOF MS

    PubMed Central

    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

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

    PubMed

    Duscher, Georg G; Hodžić, Adnan; Weiler, Martin; Vaux, Alexander G C; Rudolf, Ivo; Sixl, Wolfdieter; Medlock, Jolyon M; Versteirt, Veerle; Hubálek, Zdenek

    2016-07-01

    In a set of pooled field collected Dermacentor reticulatus ticks, Rickettsia raoultii, the causative agent of Tick-borne lymphadenopathy/Dermacentor-borne necrosis erythema and lymphadenopathy, was found for the first time in Austria. The coordinates of the positive locations for tick and pathogen abundance are given and shown in a map.

  3. Severe human infection with Rickettsia felis associated with hepatitis in Yucatan, Mexico.

    PubMed

    Zavala-Castro, Jorge; Zavala-Velázquez, Jorge; Walker, David; Pérez-Osorio, Jorge; Peniche-Lara, Gaspar

    2009-11-01

    Rickettsia felis infection usually is a mild-to-moderate illness characterized by general signs and symptoms. Generally, patients do not require hospitalization. However, we detected 2 severe infections with R. felis. Our findings support the importance of R. felis infection as a potentially severe illness in humans.

  4. Fatal human infection with Rickettsia rickettsii, Yucatán, Mexico.

    PubMed

    Zavala-Castro, Jorge E; Zavala-Velázquez, Jorge E; Walker, David H; Ruiz Arcila, Edgar E; Laviada-Molina, Hugo; Olano, Juan P; Ruiz-Sosa, José A; Small, Melissa A; Dzul-Rosado, Karla R

    2006-04-01

    The first fatal Rickettsia rickettsii infection was diagnosed in the southwest of Mexico. The patient had fever, erythematous rash, abdominal pain, and severe central nervous system involvement with convulsive crisis. The diagnosis of R. rickettsii infection was established by immunohistochemistry and specific polymerase chain reaction.

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

    PubMed

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

    2011-09-01

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

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

    PubMed

    Berrada, Zenda L; Goethert, Heidi K; Cunningham, Jenny; Telford, Sam R

    2011-03-01

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

  7. Identification of rickettsiae from ticks collected in the Central African Republic using the polymerase chain reaction.

    PubMed

    Dupont, H T; Cornet, J P; Raoult, D

    1994-03-01

    Spotted fever rickettsiosis have been identified on the African continent since their historical description in 1909. However, only Rickettsia conorii and R. africae have been described in Africa, and the current techniques for the detection of rickettsiae in ticks are difficult to apply in large field studies. We report here a preliminary study using genomic amplification by the polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) analysis directly on 310 crushed ticks (Rhipicephalus, Amblyomma, and Haemaphysalis species) collected in 1985 in the Central African Republic. Among 310 specimen tested, 21.6% were positive. The rate of infection ranged from 0% to 64.3%, depending on the tick species. Based on PCR-RFLP, five different rickettsiae profiles were found: R. conorii and R. africae, previously known in Africa, R. rhipicephali, which has never been described in Africa, and two isolates identical to R. massiliae and Mtu5, previously obtained from Rh. turanicus in southern France. This work shows that PCR-RFLP is a powerful tool to study tick collections, and that it is applicable to samples from developing countries. Further work is needed to confirm the identification of the rickettsiae found in this work, using traditional identification procedures.

  8. Severe Fever with Thrombocytopenia Syndrome Complicated by Co-infection with Spotted Fever Group Rickettsiae, China.

    PubMed

    Lu, Qing-Bin; Li, Hao; Zhang, Pan-He; Cui, Ning; Yang, Zhen-Dong; Fan, Ya-Di; Cui, Xiao-Ming; Hu, Jian-Gong; Guo, Chen-Tao; Zhang, Xiao-Ai; Liu, Wei; Cao, Wu-Chun

    2016-11-01

    During 2013-2015 in central China, co-infection with spotted fever group rickettsiae was identified in 77 of 823 patients infected with severe fever with thrombocytopenia syndrome virus. Co-infection resulted in delayed recovery and increased risk for death, prompting clinical practices in the region to consider co-infection in patients with severe fever with thrombocytopenia syndrome.

  9. Apoptosis of lymphocytes in mice induced by infection with Rickettsia tsutsugamushi.

    PubMed Central

    Kasuya, S; Nagano, I; Ikeda, T; Goto, C; Shimokawa, K; Takahashi, Y

    1996-01-01

    Histological examinations of mice infected with either a lethal (Karp) or a self-limitating (Gilliam) strain of Rickettsia tsutsugamushi were performed. Tingible body macrophages in the spleen and necrotizing lymphadenitis in regional lymph nodes were prominent only in the former. Apoptotic legions in the lymphocytes of these organs were clearly demonstrated by histochemical and electron microscopical examinations. PMID:8751955

  10. Selective Concentration of Bacteria and Rickettsia with the Aid of Polycondensation Immunosorbents,

    DTIC Science & Technology

    preparation of specific immunosorbents by acting upon globulins of corresponding hyperimmune sera with 4,4-bisdiphenylendiasonium; conjugation of...immunosorbents from globulins of hyperimmune sera of P. pestis and D. sibiricus rickettsia. A possibility was demonstrated of lyophilization of immunosorbents

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

    PubMed

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

    2015-06-01

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

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

    PubMed

    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

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

    PubMed

    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.

  14. "Rickettsia amblyommii" and R. montanensis infection in dogs following natural exposure to ticks.

    PubMed

    Barrett, Anne; Little, Susan E; Shaw, Edward

    2014-01-01

    To determine the risk of canine infection with spotted fever group (SFG) Rickettsia spp. following natural tick exposure, 10 dogs determined to be free of evidence of exposure to or infection with tick-borne disease agents were exposed to ticks via weekly walks in a wooded area in north-central Oklahoma. After each walk, dogs were examined and the number and species of ticks present were recorded. The dogs were then returned to outdoor kennels to allow the infestations and subsequent transmission of any pathogens to proceed. Serum samples and whole blood were collected from each dog twice weekly for 121 days and evaluated via indirect fluorescence antibody (IFA) for antibodies reactive to Rickettsia rickettsii, R. montanensis, and "R. amblyommii," and by PCR for evidence of Rickettsia spp. Dogs became infested with a total of 57-108 ticks over the entire 8-week infestation period (weekly average tick infestation=12.0±4.1). The great majority of the ticks present were Amblyomma americanum (90.5%), with a small number of Dermacentor variabilis and A. maculatum also identified. All (10/10) dogs seroconverted to R. rickettsii, R. montanensis, and "R. amblyommii," with mean maximum inverse titers of 1176, 1448, and 6654, respectively, for all dogs in the study. Maximum inverse titers to "R. amblyommii" ranged from 4096 to 16,384 and were higher in 9/10 dogs than maximum inverse titers to R. rickettsii or R. montanensis. Sequence-confirmed SFG Rickettsia spp. (R. montanensis and "R. amblyommii") were occasionally, but not consistently, identified from whole blood by PCR. Taken together, our data suggest that, in areas where A. americanum is common, antibodies reactive to R. rickettsii in dogs may be due instead to infection with "R. amblyommii" or other, closely related SFG Rickettsia spp.

  15. Molecular evidence for novel tick-associated spotted fever group rickettsiae from Thailand.

    PubMed

    Hirunkanokpun, Supanee; Kittayapong, Pattamaporn; Cornet, Jean-Paul; Gonzalez, Jean-Paul

    2003-03-01

    Ticks are of considerable medical and veterinary importance because they directly harm the host through their feeding action and indirectly through vectoring many bacterial pathogens. Despite many ticks being known from Thailand, very little is known about the bacteria they may harbor. We report here the results of a survey of tick-associated bacteria in Thailand. A total of 334 individuals representing 14 species of ticks in five genera were collected from 10 locations in Thailand and were examined for the human pathogens, Borrelia, Francisella, Rickettsia, and the common arthropod endosymbionts, Wolbachia, by polymerase chain reaction (PCR) assay using specific primers. Rickettsial DNA was detected in 30% (9/30) of Amblyomma testudinarium (Koch, 1844) collected from Khao Yai National Park, Nakhon Nayok Province and 16.84% (16/95) of Hemaphysalis ornithophila (Hoogstraal and Kohls, 1959) collected from Khao Yai National Park, Nakhon Nayok Province and Khao Ang Rue Nai Wildlife Sanctuary, Chachoengsao Province. Rickettsial DNA was not detected in any of the other tick species and no DNA of Borrelia, Francisella, or Wolbachia was detected in any of 14 tick species. Phylogenetic relationships among the rickettsiae detected in this study and those of other rickettsiae were inferred from comparison of sequences of the 17-kDa antigen gene, the citrate synthase gene (gltA), and the 190-kDa outer membrane protein gene (ompA). Results indicated that the three Thai rickettsiae detected in this study represent new rickettsial genotypes and form a separate cluster among the spotted fever group rickettsiae.

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

    PubMed

    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.

  17. Wife carrying for health.

    PubMed

    Lee, I-Min; Titze, Sylvia; Oja, Pekka

    2011-12-19

    To highlight a fun activity--the sport of wife carrying--and to investigate factors associated with better performance. Cross-sectional study based in Sonkajärvi, Finland (venue of the annual Wife Carrying World Championship race), of 172 couples participating in wife-carrying races, 1992-2010. Race finishing time. The mean age for male participants was 32.6 (SD, 8.7) years and for female participants, 30.5 (SD, 9.2) years. The mean finishing time was 98 s. Finish times tended to be somewhat slower as the age of the male partner increased (P = 0.06), but not as the female partner's age increased (P = 0.89). Race experience was not associated with faster times (P = 0.88). Estonians were almost 12 s faster than other nationalities, although this was not statistically significant (P = 0.25), probably due to the small number of Estonians. Men who engaged in endurance-type physical activities as hobbies (P = 0.003), or in both endurance- and strength-building activities (P = 0.001), were significantly faster than those who did neither. Among women, strength-building (P = 0.03) but not endurance-type (P = 0.36) physical activities were significantly associated with faster race times. Wife carrying can be a novel option for increasing physical activity levels, which improve health. Although some key data were unavailable, such as wife's body weight, and injury rates, this study identified several factors associated with better performance in this sport.

  18. Closing the gaps between genotype and phenotype in Rickettsia rickettsii.

    PubMed

    Eremeeva, Marina E; Dasch, Gregory A

    2009-05-01

    Rocky Mountain spotted fever (RMSF) caused by Rickettsia rickettsii is a severe rickettsiosis that occurs in nearly every state of the continental USA. RMSF is endemic in Central and Southern America, with recent well-documented cases in Mexico, Costa Rica, Panama, Colombia, Brazil, and Argentina. RMSF is the most malignant among known rickettsioses causing severe multiorgan dysfunction and high case fatality rates, which can reach 73% in untreated cases. Variations in pathogenic biotypes of R. rickettsii isolates have been described, and potential correlations of these differences to various clinical manifestations of RMSF have been suggested. We have recently reported on a method of genetic comparison employing sequence differences in intergenic regions (IGR typing) in isolates of R. rickettsii of human, tick, and animal origin. The grouping obtained correlated well with 2 other genotyping systems we have developed, which target the presence and distribution of variable numbers of tandem repeats (TR) and insertion/deletion (INDEL) events. Twenty-five total genotypes of R. rickettsii in 4 primary groups could be distinguished: isolates from Montana, isolates associated with Rhipicephalus sanguineus ticks and human infections in Arizona, other isolates from the USA where Dermacentor variabilis is thought to be the primary vector, and the isolates primarily associated with Amblyomma ticks from Central and South America. In addition, isolate Hlp#2, which is often considered to be a nonpathogenic isolate of R. rickettsii and closely related serotype 364D, exhibited the most diversity from the other isolates compared, and they differ significantly from each other. Because complex interactions underlie the pathogenesis of R. rickettsii in vivo, it is difficult to define the causality of individual events that occur in infected vertebrate hosts and humans. Many microbial factors are likely to contribute to the varied ability of R. rickettsii to cause cellular injury

  19. Spotted fever group Rickettsia in Amblyomma dubitatum tick from the urban area of Campo Grande, Mato Grosso do Sul, Brazil.

    PubMed

    Matias, Jaqueline; Garcia, Marcos Valério; Cunha, Rodrigo Casquero; Aguirre, André de Abreu Rangel; Barros, Jacqueline Cavalvante; Csordas, Bárbara Guimarães; Andreotti, Renato

    2015-03-01

    Rickettsia infection of each tick was evaluated by the hemolymph test and polymerase chain reaction (PCR) targeting gltA and ompA genes. All hemolymph tests were negative and PCR of one A. dubitatum detected both Rickettsia genes. Sequence of ompA exhibited a 99% identity with Rickettsia parkeri and R. africae and a 98% identity with R. sibirica. Rickettsia of the spotted fever group in A. dubitatum is described for the first time in an urban area within the municipality of Campo Grande in the state of Mato Grosso do Sul (MS), Brazil. This finding reinforces the importance of more detailed studies to determine the role of A. dubitatum in the transmission of spotted fever agents.

  20. Molecular detection of Rickettsia felis and Bartonella henselae in dog and cat fleas in Central Oromia, Ethiopia.

    PubMed

    Kumsa, Bersissa; Parola, Philippe; Raoult, Didier; Socolovschi, Cristina

    2014-03-01

    Fleas are important vectors of several Rickettsia and Bartonella spp. that cause emerging zoonotic diseases worldwide. In this study, 303 fleas collected from domestic dogs and cats in Ethiopia and identified morphologically as Ctenocephalides felis felis, C. canis, Pulex irritans, and Echidnophaga gallinacea were tested for Rickettsia and Bartonella DNA by using molecular methods. Rickettsia felis was detected in 21% of fleas, primarily C. felis, with a similar prevalence in fleas from dogs and cats. A larger proportion of flea-infested dogs (69%) than cats (37%) harbored at least one C. felis infected with R. felis. Rickettsia typhi was not detected. Bartonella henselae DNA was detected in 6% (2 of 34) of C. felis collected from cats. Our study highlights the likelihood of human exposure to R. felis, an emerging agent of spotted fever, and B. henselae, the agent of cat-scratch disease, in urban areas in Ethiopia.

  1. Molecular Detection of Rickettsia felis and Bartonella henselae in Dog and Cat Fleas in Central Oromia, Ethiopia

    PubMed Central

    Kumsa, Bersissa; Parola, Philippe; Raoult, Didier; Socolovschi, Cristina

    2014-01-01

    Fleas are important vectors of several Rickettsia and Bartonella spp. that cause emerging zoonotic diseases worldwide. In this study, 303 fleas collected from domestic dogs and cats in Ethiopia and identified morphologically as Ctenocephalides felis felis, C. canis, Pulex irritans, and Echidnophaga gallinacea were tested for Rickettsia and Bartonella DNA by using molecular methods. Rickettsia felis was detected in 21% of fleas, primarily C. felis, with a similar prevalence in fleas from dogs and cats. A larger proportion of flea-infested dogs (69%) than cats (37%) harbored at least one C. felis infected with R. felis. Rickettsia typhi was not detected. Bartonella henselae DNA was detected in 6% (2 of 34) of C. felis collected from cats. Our study highlights the likelihood of human exposure to R. felis, an emerging agent of spotted fever, and B. henselae, the agent of cat-scratch disease, in urban areas in Ethiopia. PMID:24445204

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

    PubMed

    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.

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

    PubMed

    Almeida, Robson F C; Garcia, Marcos V; Cunha, Rodrigo C; Matias, Jaqueline; Labruna, Marcelo B; Andreotti, Renato

    2013-02-01

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

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

    PubMed

    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.

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

    PubMed

    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.

  6. Use of a Sensitive Microplate Enzyme-Linked Immunosorbent Assay in a Retrospective Serological Analysis of a Laboratory Population at Risk to Infection with Typhus Group Rickettsiae

    DTIC Science & Technology

    1980-01-01

    SEROLOGICAL ANALYSIS OF A _ABORATORY -OPULATIO14 AT RISK TO INFECTION WITH ,TPHUS GROUP RICKETTSIAS . z.Z S. Halle and G.A. De ch II J. Vorosmarti, CAPT, MC, USN...number) ELISA, serodiagnosis, human subjects, immunity, typhus rickettsiae 20. ABSTRACT (Continue on reverse side if neceseary and Identify by block...linked immunosorbent assay (ELISA), developed for the detection of antibodies to typhus group rickettsiae , was used to analyze human sera from

  7. Orientia, rickettsia, and leptospira pathogens as causes of CNS infections in Laos: a prospective study

    PubMed Central

    Dittrich, Sabine; Rattanavong, Sayaphet; Lee, Sue J; Panyanivong, Phonepasith; Craig, Scott B; Tulsiani, Suhella M; Blacksell, Stuart D; Dance, David A B; Dubot-Pérès, Audrey; Sengduangphachanh, Amphone; Phoumin, Phonelavanh; Paris, Daniel H; Newton, Paul N

    2015-01-01

    Summary Background Scrub typhus (caused by Orientia tsutsugamushi), murine typhus (caused by Rickettsia typhi), and leptospirosis are common causes of febrile illness in Asia; meningitis and meningoencephalitis are severe complications. However, scarce data exist for the burden of these pathogens in patients with CNS disease in endemic countries. Laos is representative of vast economically poor rural areas in Asia with little medical information to guide public health policy. We assessed whether these pathogens are important causes of CNS infections in Laos. Methods Between Jan 10, 2003, and Nov 25, 2011, we enrolled 1112 consecutive patients of all ages admitted with CNS symptoms or signs requiring a lumbar puncture at Mahosot Hospital, Vientiane, Laos. Microbiological examinations (culture, PCR, and serology) targeted so-called conventional bacterial infections (Streptococcus pneumoniae, 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 conventional bacterial infections (90/1051 [9%] vs 42/1051 [4%]; p<0·0001) by use of conservative diagnostic definitions. CNS infections had a high mortality (236/876 [27%]), with 18% (13/71) for R typhi/Rickettsia spp, O tsutsugamushi, and Leptospira spp combined, and 33% (13/39) for conventional bacterial infections (p=0·076). Interpretation Our data suggest that R typhi/Rickettsia spp, O tsutsugamushi, and Leptospira spp infections are important causes of CNS infections in Laos

  8. Rickettsia Species Infecting Amblyomma cooperi Ticks from an Area in the State of São Paulo, Brazil, Where Brazilian Spotted Fever Is Endemic

    PubMed Central

    Labruna, Marcelo B.; Whitworth, Ted; Horta, Maurício C.; Bouyer, Donald H.; McBride, Jere W.; Pinter, Adriano; Popov, Vsevolod; Gennari, Solange M.; Walker, David H.

    2004-01-01

    Owing to the potential role of the tick Amblyomma cooperi in the enzootic cycle of Rickettsia rickettsii, the etiologic agent of Brazilian spotted fever (BSF), this study evaluated infection by Rickettsia species in A. cooperi ticks collected from an area in Brazil where BSF is endemic. Among a total of 40 A. cooperi adult ticks collected in an area of BSF endemicity in the state of São Paulo, PCR analysis detected DNA of Rickettsia bellii in 16 ticks (40%), and 3 other ticks (7.5%) were positive for a previously unidentified spotted-fever-group (SFG) rickettsia. Cultivation in Vero cell cultures by the shell vial technique with individual A. cooperi ticks resulted in two isolates of R. bellii and one isolate genotypically characterized as an SFG rickettsia. The two R. bellii isolates were established in Vero cell cultures in the laboratory and were confirmed to be R. bellii by molecular analysis of the gltA and 17-kDa protein-encoding genes and by electron microscopic analysis. The SFG rickettsial isolate could not be stably passaged in cell culture in the laboratory, but molecular analysis of early passages suggested that it was closely related to Rickettsia parkeri, Rickettsia africae, and Rickettsia sibirica. These results do not support the role of A. cooperi in the ecology of R. rickettsii in the area studied, but they add two more species of rickettsiae to the poorly developed list of species occurring in ticks in South America. PMID:14715737

  9. A spotted fever group Rickettsia from an exotic tick species, Amblyomma exornatum (Acari: Ixodidae), in a reptile breeding facility in the United States.

    PubMed

    Reeves, Will K; Durden, Lance A; Dasch, Gregory A

    2006-09-01

    Adults and nymphs of Amblyomma exornatum Koch (Acari: Ixodidae), an exotic African tick of monitor lizards, were collected from a Gray's monitor lizard, Varanus olivaceus Hallowell, that died in a reptile facility in Alabama. Nine adult ticks were tested by polymerase chain reaction for rickettsial agents. DNA from a novel spotted fever group Rickettsia was amplified and sequenced from one of the nine ticks. The novel Rickettsia was most similar to "Rickettsia anan," which is associated with Amblyomma from Asia. The detection of a spotted fever group Rickettsia in exotic ticks emphasizes the potential threat posed by the importation and propagation of exotic animals in the United States.

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

    PubMed

    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 strain of R

  11. Ectoparasite Infestations and Canine Infection by Rickettsiae and Ehrlichiae in a Semi-Arid Region of Northeastern Brazil

    PubMed Central

    Araes-Santos, Ana Isabel; Moraes-Filho, Jonas; Peixoto, Renata M.; Spolidorio, Mariana G.; Azevedo, Sérgio S.; Costa, Mateus M.; Labruna, Marcelo B.

    2015-01-01

    Abstract This study investigated the prevalence of Rickettsia spp. and Ehrlichia canis infection in dogs and their ectoparasites from rural and urban areas of two municipalities, Petrolina and Juazeiro, within a semiarid region (Caatinga biome) of northeastern Brazil, by immunofluorescence assay (IFA) and polymerase chain reaction (PCR). Overall, 12.1% (61/504) and 23.0% (116/504) of canine plasma samples had antibodies reactive to Rickettsia spp. and E. canis. E. canis DNA was detected by PCR in 8.3% (42/504) of canine blood samples, whereas no blood sample was positive for Rickettsia spp. The infection by E. canis was determined by PCR in 4.9% (14/285) Rhipicephalus sanguineus sensu lato (s.l.) ticks and by Rickettsia felis in 1.1% (3/285) and 40.6% (74/182) ticks and fleas, respectively. Multivariate regression analyses revealed that canine seropositivity to Rickettsia spp. was associated statistically with the variables “to reside in Petrolina” and “presence of ectoparasites.” Our results indicate that canine infection by E. canis might be endemic in the Caatinga biome as it is in other Brazilian biomes. Although no previous serosurvey for Rickettsia spp. has been conducted on dogs from the Caatinga biome, our values are much lower than the ones reported for rural dogs from other Brazilian biomes. These differences are likely related to the semiarid climate of the aatinga biome, which minimizes the exposure of rural dogs to Amblyomma spp. ticks, the most common vectors of Rickettsia spp. in Brazil. Considering that dogs are excellent sentinels for human exposure to Rickettsia spp., we can infer that the risks of human acquiring tick-borne rickettsiosis in the Caatinga region of the present study are low. The rickettsial infection rates in fleas and ticks were not related to canine seropositivity; i.e., areas with higher Rickettsia infection rates in fleas had the lowest canine seroreactivity to Rickettsia spp. PMID:26565771

  12. First detection of Rickettsia aeschlimannii in Hyalomma dromedarii ticks from Tunisia.

    PubMed

    Demoncheaux, Jean-Paul; Socolovschi, Cristina; Davoust, Bernard; Haddad, Slim; Raoult, Didier; Parola, Philippe

    2012-12-01

    Tick-borne rickettsioses have long been described in North Africa. These human diseases and their causative agents occur in several countries in this region, including Mauritania, Morocco, Algeria, Tunisia, Libya, and Egypt. In Tunisia, the first described and most well-known rickettsiosis is Mediterranean spotted fever, which is caused by Rickettsia conorii conorii. Cases of R. aeschlimannii infections have been documented by serology, but the agent has never actually been detected in patients or arthropods in the country. In October 2008, ticks were collected from a dromedary (Camelius dromedarii) in Douz, Central Tunisia. All of the ticks were identified as Hyalomma dromedarii and were tested using polymerase chain reaction to determine the presence of rickettsiae. Our results indicate the first molecular detection of R. aeschlimannii in ticks from Tunisia. Copyright © 2012 Elsevier GmbH. All rights reserved.

  13. Prevalence and infection intensity of Rickettsia massiliae in Rhipicephalus sanguineus sensu lato ticks from Mendoza, Argentina.

    PubMed

    Monje, Lucas D; Linares, María Cielo; Beldomenico, Pablo M

    2016-11-01

    Rickettsia massiliae belongs to the spotted fever group and in the New World is commonly associated with the brown dog tick, Rhipicephalus sanguineus. Herein we investigate the presence of R. massiliae in Rh. sanguineus sensu lato ticks in a location near the Andean foothills (Mendoza, Argentina), to provide a prevalence estimate and to assess the infection intensity of this pathogen. Rickettsia massiliae infection was found in 5.1% of the Rh. sanguineus s.l ticks analyzed, all with high infection intensities. Molecular analysis determined that all R. massiliae-infected Rh. sanguineus s.l. ticks belonged to the temperate lineage. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  14. Molecular survey of Rickettsia, Ehrlichia, and Anaplasma infection of domestic cats in Japan.

    PubMed

    Sasaki, Hiromi; Ichikawa, Yasuaki; Sakata, Yoshimi; Endo, Yasuyuki; Nishigaki, Kazuo; Matsumoto, Kotaro; Inokuma, Hisashi

    2012-12-01

    The prevalence of Rickettsia, Ehrlichia, and Anaplasma in 1764 DNA samples extracted from feline peripheral blood from all 47 prefectures in Japan was evaluated by screening real-time PCR, genus-specific PCR, and DNA nucleotide sequencing. The survey revealed that all cats were negative for Rickettsia infection. Two cats were positive for Ehrlichia or Anaplasma based on the screening PCR assay. Nucleotide sequence analysis of the partial 16S rRNA including the divergent region near the 3'-end revealed that the 2 positives were most similar to Anaplasma bovis with percent identities of 99.8% and 99.2%. This was the first detection of A. bovis DNA fragments in cats. Although these 2 cats showed stomatitis, both were also infected with feline immunodeficiency virus. The relationship between A. bovis carriage and clinical disease is not yet understood.

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

    USGS Publications Warehouse

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

    1969-01-01

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

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

    PubMed

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

    2014-10-01

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

  17. Mechanisms of immunity in typhus infection: adoptive transfer of immunity to Rickettsia mooseri.

    PubMed Central

    Murphy, J R; Wisseman, C G; Fiset, P

    1979-01-01

    When nonimmune guinea pigs are inoculated intradermally (i.d.) with Rickettsia mooseri (R. typhi), the rickettsiae replicate at the site of inoculation, leading to the development of a grossly observable lesion. In contrast, guinea pigs which have recovered from R. mooseri infection are resistant to challenge and prevent both rickettsial growth and the formation of lesions. To study the mechanisms of this immunity, sera or splenic cells collected from nonimmune or immune guinea pigs were inoculated separetely into nonimmune recipients. Splenic cells collected from immune donors protected R. mooseri-naive recipients from i.d. challenge as measured by control of rickettsial growth and by prevention of development of lesions at i.d. sites of inoculation. In contrast, serum from immune and nonimmune doners failed to protect nonimmune recipients by either criterion. PMID:110699

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

    PubMed

    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.

  19. Defending the fort: a role for defensin-2 in limiting Rickettsia montanensis infection of Dermacentor variabilis

    PubMed Central

    Pelc, R S; McClure, J C; Sears, K T; Chung, A; Rahman, M S; Ceraul, S M

    2014-01-01

    The importance of tick defensins is evidenced by their expression in a wide variety of tick tissues and prevalence across many tick genera. To date, the functional and biological significance of defensin-2 as a rickettsiastatic or rickettsiacidal antimicrobial peptide has not been addressed. In a previous study, defensin-2 transcription was shown to increase in Dermacentor variabilis ticks challenged with Rickettsia montanensis. In the present study, the hypothesis that defensin-2 is functional as a rickettsiastatic and/or rickettsiacidal antimicrobial peptide is tested. We show that defensin-2 plays a role in reducing burden after acquisition of Rickettsia montanensis through capillary feeding. Moreover, defensin-2 is shown to associate with R. montanensis in vitro and in vivo, causing cytoplasmic leakiness. PMID:24779891

  20. Molecular detection of spotted fever group rickettsiae in ticks from Ethiopia and Chad.

    PubMed

    Mura, Alessandra; Socolovschi, Cristina; Ginesta, Jacques; Lafrance, Bertrand; Magnan, Stéphan; Rolain, Jean-Marc; Davoust, Bernard; Raoult, Didier; Parola, Philippe

    2008-09-01

    DNA extracted from 363 ticks collected in Ethiopia and 9 ticks collected in Chad, Africa were screened by PCR to detect DNA from spotted fever group rickettsiae. Fifteen ticks (4.1%) collected in Ethiopia and one tick (11%) collected in Chad tested positive when PCR targeting the gltA and ompA rickettsial genes was performed. PCR-positive products of the gltA and ompA genes were used for DNA sequencing. Rickettsia africae was detected in 12/118 Amblyomma lepidum and in 1/2 A. variegatum. Also, 2/12 Hyalomma marginatum rufipes collected in Ethiopia and one H. marginatum rufipes collected in Chad were positive for R. aeschlimannii. Our results confirm the previously reported presence of R. africae in Ethiopia and also show the first evidence of R. aeschlimannii in ticks collected in Ethiopia and Chad.

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

    PubMed

    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.

  2. Ticks on passerines from the Archipelago of the Azores as hosts of borreliae and rickettsiae.

    PubMed

    Literak, Ivan; Norte, Ana Claudia; Núncio, Maria Sofia; de Carvalho, Isabel Lopes; Ogrzewalska, Maria; Nováková, Markéta; Martins, Thiago F; Sychra, Oldrich; Resendes, Roberto; Rodrígues, Pedro

    2015-07-01

    We examined the presence of borreliae and rickettsiae bacteria in ticks from wild passerine birds on three islands of the Archipelago of the Azores, the westernmost region of Palearctic. A total of 266 birds belonging to eight species from seven families were examined on São Miguel, Santa Maria and Graciosa islands in 2013. Ticks collected from these birds consisted of 55 Ixodes frontalis (22 larvae, 32 nymphs, 1 adult female) and 16 Haemaphysalis punctata nymphs. Turdus merula and Erithacus rubecula were the birds most infested with both tick species. Three T. merula in Santa Maria were infested with 4 I. frontalis infected with Borrelia turdi. No rickettsiae were found in the ticks. We report for the first time the presence of I. frontalis and B. turdi on the Azores islands and we showed that the spatial distribution reaches further west than previously thought.

  3. Transposon insertion reveals pRM, a plasmid of Rickettsia monacensis.

    PubMed

    Baldridge, Gerald D; Burkhardt, Nicole Y; Felsheim, Roderick F; Kurtti, Timothy J; Munderloh, Ulrike G

    2007-08-01

    Until the recent discovery of pRF in Rickettsia felis, the obligate intracellular bacteria of the genus Rickettsia (Rickettsiales: Rickettsiaceae) were thought not to possess plasmids. We describe pRM, a plasmid from Rickettsia monacensis, which was detected by pulsed-field gel electrophoresis and Southern blot analyses of DNA from two independent R. monacensis populations transformed by transposon-mediated insertion of coupled green fluorescent protein and chloramphenicol acetyltransferase marker genes into pRM. Two-dimensional electrophoresis showed that pRM was present in rickettsial cells as circular and linear isomers. The 23,486-nucleotide (31.8% G/C) pRM plasmid was cloned from the transformant populations by chloramphenicol marker rescue of restriction enzyme-digested transformant DNA fragments and PCR using primers derived from sequences of overlapping restriction fragments. The plasmid was sequenced. Based on BLAST searches of the GenBank database, pRM contained 23 predicted genes or pseudogenes and was remarkably similar to the larger pRF plasmid. Two of the 23 genes were unique to pRM and pRF among sequenced rickettsial genomes, and 4 of the genes shared by pRM and pRF were otherwise found only on chromosomes of R. felis or the ancestral group rickettsiae R. bellii and R. canadensis. We obtained pulsed-field gel electrophoresis and Southern blot evidence for a plasmid in R. amblyommii isolate WB-8-2 that contained genes conserved between pRM and pRF. The pRM plasmid may provide a basis for the development of a rickettsial transformation vector.

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

    PubMed Central

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

    2016-01-01

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

  5. Bacterial diversity in Amblyomma americanum (Acari: Ixodidae) with a focus on members of the genus Rickettsia.

    PubMed

    Heise, Stephanie R; Elshahed, M S; Little, S E

    2010-03-01

    The lone star tick, Amblyomma americanum (Acari: Ixodidae), is commonly reported from people and animals throughout the eastern U.S. and is associated with transmission of a number of emerging diseases. To better define the microbial communities within lone star ticks, 16S rRNA gene based analysis using bacteria-wide primers, followed by sequencing of individual clones (n = 449) was used to identify the most common bacterial operational taxonomic units (OTUs) present within colony-reared and wild A. americanum. The colony-reared ticks contained primarily sequence affiliated with members of the genus Coxiella (89%; 81/91), common endosymbionts of ticks, and Brevibacterium (11%; 10/91). Similarly, analysis of clones from unfed wild lone star ticks revealed that 96.7% (89/92) of all the OTUs identified were affiliated with Coxiella-like endosymbionts, as compared with only 5.1-11.7% (5/98-9/77) of those identified from wild lone star ticks after feeding. In contrast, the proportion of OTUs identified as Rickettsia sp. in wild-caught ticks increased from 2.2% (2/92) before feeding to as high as 46.8% (36/77) after feeding, and all Rickettsia spp. sequences recovered were most similar to those described from the spotted fever group Rickettsia, specifically R. amblyommii and R. massiliae. Additional characterization of the Rickettsiales tick community by polymerase chain reaction, cloning, and sequencing of 17 kDa and gltA genes confirmed these initial findings and suggested that novel Rickettsia spp. are likely present in these ticks. These data provide insight into the overall, as well as the rickettsial community of wild lone star ticks and may ultimately aid in identification of novel pathogens transmitted by A. americanum.

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

    DTIC Science & Technology

    2005-01-01

    ompA, and sca4) from two molecular isolates of Candidatus Rickettsia andeanae from two ticks ( Amblyomma maculatum and Ixodes boliviensis) col- lected...andeanae from two ticks ( Amblyomma maculatum and Ixodes boliviensis) collected from domestic horses liv- ing in two separate locations in Northern Peru...scribed previously.2 However, new primers were used for PCR and sequencing in this study (TABLE 1). The sequences (both forward and reverse) were

  7. Detection of Rickettsia felis in a New World flea species, Anomiopsyllus nudata (Siphonaptera: Ctenophthalmidae).

    PubMed

    Stevenson, Heather L; Labruna, Marcelo B; Montenieri, John A; Kosoy, Michael Y; Gage, Kenneth L; Walker, David H

    2005-03-01

    The flea and rodent samples studied in this project were collected from field study sites in New Mexico from winter 1998 to spring 2001. During this period, 155 small rodents (14 different species) were live-trapped and combed for the presence of fleas. A total of 253 fleas were collected, comprising 21 species. Two of the 253 fleas collected were polymerase chain reaction (PCR) positive for the Rickettsia 17-kDa protein gene. These two fleas were both Anomiopsyllus nudata Baker, each collected from an individual Neotoma albigula Hartley, on two occasions. Individual fleas positive for the Rickettsia 17-kDa protein gene were then tested with primers targeting the rickettsial genes for citrate synthase (gltA) and two major outer membrane proteins (ompA and ompB). The nucleotide sequences of the PCR products of these two fleas were identical to each other and were 100% (394/394), 100% (1150/1150), 99.8% (469/470), and 99.3% (818/824) similar to the corresponding sequences of the 17-kDa, gltA, ompA, and ompB genes of Rickettsia felis, respectively. Flea homogenates of individual PCR-positive fleas were inoculated into shell vials seeded with Vero cells, and the Gimenez stain technique was used to demonstrate the presence of Rickettsia-like organisms in detached cells found in aspirated medium 19 d after inoculation. These cells were harvested and tested by PCR, targeting portions of the 17-kDa and gltA genes, resulting in products 100% identical to R. felis. This work comprises the first report of R. felis detection in a flea species (A. nudata) endemic to the New World.

  8. Disrupting Protein Expression with Peptide Nucleic Acids Reduces Infection by Obligate Intracellular Rickettsia

    PubMed Central

    Pelc, Rebecca S.; McClure, Jennifer C.; Kaur, Simran J.; Sears, Khandra T.; Rahman, M. Sayeedur; Ceraul, Shane M.

    2015-01-01

    Peptide Nucleic Acids (PNAs) are single-stranded synthetic nucleic acids with a pseudopeptide backbone in lieu of the phosphodiester linked sugar and phosphate found in traditional oligos. PNA designed complementary to the bacterial Shine-Dalgarno or start codon regions of mRNA disrupts translation resulting in the transient reduction in protein expression. This study examines the use of PNA technology to interrupt protein expression in obligate intracellular Rickettsia sp. Their historically intractable genetic system limits characterization of protein function. We designed PNA targeting mRNA for rOmpB from Rickettsia typhi and rickA from Rickettsia montanensis, ubiquitous factors important for infection. Using an in vitro translation system and competitive binding assays, we determined that our PNAs bind target regions. Electroporation of R. typhi and R. montanensis with PNA specific to rOmpB and rickA, respectively, reduced the bacteria’s ability to infect host cells. These studies open the possibility of using PNA to suppress protein synthesis in obligate intracellular bacteria. PMID:25781160

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

    PubMed Central

    Bohacsova, Monika; Mediannikov, Oleg; Kazimirova, Maria; Raoult, Didier; Sekeyova, Zuzana

    2016-01-01

    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. PMID:26901622

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

    PubMed Central

    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

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

    PubMed

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

    2012-12-01

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

  12. Characterization of Sicilian strains of spotted fever group rickettsiae by using monoclonal antibodies.

    PubMed Central

    Vitale, G; Di Stefano, R; Damiani, G; Mansueto, S

    1989-01-01

    Twenty-two hybridomas producing anti-Rickettsia conorii monoclonal antibodies were obtained by nine fusion experiments. The strain chosen for immunization of mice was MAVI, an R. conorii strain isolated from a Sicilian patient with Boutonneuse fever. When tested for immunoglobulin isotype by an indirect immunofluorescence (IIF) assay, 46.6% of supernatants from the 22 hybridomas were immunoglobulin M. The supernatants were tested in the IIF assay for binding to the MAVI strain and four spotted fever group rickettsia strains isolated from Sicilian ticks (two virulent and two nonpathogenic when inoculated intraperitoneally in male guinea pigs). Only five of the supernatants showed a positive IIF result on all tested strains, although they produced different titers to the various strains, possibly an indication that they recognized an antigen common to spotted fever group rickettsiae. Immunodominant epitopes for humans were determined by using patient sera to analyze inhibition of binding to the MAVI strain. Although a limited number of serum samples were screened, a high percentage of Boutonneuse fever patients produced antibodies recognizing the same epitopes as were recognized by the mouse monoclonal antibodies. A striking heterogeneity was found both in the expression of mouse-recognized epitopes on the five rickettsial strains and in the serum antibody responses of Boutonneuse fever patients to these epitopes. PMID:2473092

  13. Isolation of Rickettsia massiliae from Rhipicephalus sanguineus Ticks, Buenos Aires (Argentina).

    PubMed

    Cicuttin, G L; De Salvo, M N; La Rosa, I; Dohmen, F E Gury

    2015-12-01

    Rickettsia massiliae , a member of the spotted fever group of Rickettsia, was first isolated from a Rhipicephalus turanicus tick in France. In the New World, it has been detected in Rhipicephalus sanguineus ticks from different geographical locations in Argentina and the United States, but it has only been isolated in Arizona. The aim of this study was the isolation and genetic characterization of R. massiliae from R. sanguineus ticks collected from dogs in Buenos Aires city, Argentina. In total, 49 R. sanguineus ticks were collected from 10 dogs and grouped into 10 pools of 4-5 specimens. With a PCR assay, which detects a fragment of the Rickettsia genus-specific 23S-5S intergenic space, 1 pool of 5 ticks was found positive. Generated sequences exhibited 100% identity with R. massiliae . A new isolate, named CABA, was obtained from this pool by inoculating it into monolayers of Vero cells. Genotypic characteristics were determined, and results showed that fragments of the 23S-5S intergenic space, ompA, ompB, gltA, htrA, and sca1 genes had great similarity with R. massiliae strain Bar29 (Spain). Although few human cases have been confirmed for this pathogen, its circulation in urban areas is of great importance to public health. This isolation improves knowledge of the circulating pathogen and could improve future diagnostic processes as it allows the production of more specific antigens for serological testing.

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

    PubMed

    Kelly, Patrick; Lucas, Helene; Beati, Lorenza; Yowell, Charles; Mahan, Suman; Dame, John

    2010-12-01

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

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

    PubMed

    Wikswo, Mary Elizabeth; Hu, Renjie; Metzger, Marco E; Eremeeva, Marina E

    2007-01-01

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

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

    PubMed

    Bohacsova, Monika; Mediannikov, Oleg; Kazimirova, Maria; Raoult, Didier; Sekeyova, Zuzana

    2016-01-01

    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.

  17. Nitric Oxide-Mediated Inhibition of the Ability of Rickettsia prowazekii To Infect Mouse Fibroblasts and Mouse Macrophagelike Cells

    PubMed Central

    Turco, Jenifer; Liu, Hua; Gottlieb, Sheldon F.; Winkler, Herbert H.

    1998-01-01

    The role of the nitric oxide synthase (NOS) pathway in inhibiting the ability of Rickettsia prowazekii to initially infect (invade) mouse cytokine-treated, fibroblastic L929 cells and macrophagelike RAW264.7 cells and the ability of nitric oxide (NO) to damage isolated rickettsiae were investigated. Substantial amounts of nitrite (a degradation product of NO) were produced and the initial rickettsial infection was suppressed in cultures of L929 cells treated with crude lymphokine preparations (LK) or with gamma interferon (IFN-γ) plus tumor necrosis factor alpha (TNF-α) but not in L929 cell cultures treated with IFN-γ alone or TNF-α alone. The NOS inhibitors NG-methyl-l-arginine and aminoguanidine both inhibited nitrite production and prevented the suppression of the initial rickettsial infection. Antibody-mediated neutralization of the IFN-γ in the LK also inhibited both nitrite production and suppression of the initial rickettsial infection. Cultures of RAW264.7 cells treated with IFN-γ plus lipopolysaccharide exhibited suppression of the initial rickettsial infection, and the suppression was relieved by aminoguanidine. Addition of oxyhemoglobin (a scavenger of extracellular NO) during the rickettsial infection alleviated the suppression of the initial rickettsial infection observed in appropriately treated L929 cells and RAW264.7 cells. In addition, the oxyhemoglobin restored the rickettsia-mediated, rapid killing of the treated RAW264.7 cells. Incubation of isolated rickettsiae with NO inhibited their ability to infect L929 and IFN-γ-treated RAW264.7 cells and to rapidly kill IFN-γ-treated RAW264.7 cells. In contrast, incubation of L929 cells with a solution that contained NO and/or degradation products of NO did not affect their ability to be infected by rickettsiae. The data are consistent with the hypothesis that NO released from appropriately stimulated potential host cells kills extracellular rickettsiae and thus prevents the rickettsiae from

  18. RalF-Mediated Activation of Arf6 Controls Rickettsia typhi Invasion by Co-Opting Phosphoinositol Metabolism.

    PubMed

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

    2016-12-01

    Rickettsiae are obligate intracellular pathogens that induce their uptake into nonphagocytic cells; however, the events instigating this process are incompletely understood. Importantly, diverse Rickettsia species are predicted to utilize divergent mechanisms to colonize host cells, as nearly all adhesins and effectors involved in host cell entry are differentially encoded in diverse Rickettsia species. One particular effector, RalF, a Sec7 domain-containing protein that functions as a guanine nucleotide exchange factor of ADP-ribosylation factors (Arfs), is critical for Rickettsia typhi (typhus group rickettsiae) entry but pseudogenized or absent from spotted fever group rickettsiae. Secreted early during R. typhi infection, RalF localizes to the host plasma membrane and interacts with host ADP-ribosylation factor 6 (Arf6). Herein, we demonstrate that RalF activates Arf6, a process reliant on a conserved Glu within the RalF Sec7 domain. Furthermore, Arf6 is activated early during infection, with GTP-bound Arf6 localized to the R. typhi entry foci. The regulation of phosphatidylinositol 4-phosphate 5-kinase (PIP5K), which generates PI(4,5)P2, by activated Arf6 is instrumental for bacterial entry, corresponding to the requirement of PI(4,5)P2 for R. typhi entry. PI(3,4,5)P3 is then synthesized at the entry foci, followed by the accumulation of PI(3)P on the short-lived vacuole. Inhibition of phosphoinositide 3-kinases, responsible for the synthesis of PI(3,4,5)P3 and PI(3)P, negatively affects R. typhi infection. Collectively, these results identify RalF as the first bacterial effector to directly activate Arf6, a process that initiates alterations in phosphoinositol metabolism critical for a lineage-specific Rickettsia entry mechanism. Copyright © 2016 Rennoll-Bankert et al.

  19. RalF-Mediated Activation of Arf6 Controls Rickettsia typhi Invasion by Co-Opting Phosphoinositol Metabolism

    PubMed Central

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

    2016-01-01

    Rickettsiae are obligate intracellular pathogens that induce their uptake into nonphagocytic cells; however, the events instigating this process are incompletely understood. Importantly, diverse Rickettsia species are predicted to utilize divergent mechanisms to colonize host cells, as nearly all adhesins and effectors involved in host cell entry are differentially encoded in diverse Rickettsia species. One particular effector, RalF, a Sec7 domain-containing protein that functions as a guanine nucleotide exchange factor of ADP-ribosylation factors (Arfs), is critical for Rickettsia typhi (typhus group rickettsiae) entry but pseudogenized or absent from spotted fever group rickettsiae. Secreted early during R. typhi infection, RalF localizes to the host plasma membrane and interacts with host ADP-ribosylation factor 6 (Arf6). Herein, we demonstrate that RalF activates Arf6, a process reliant on a conserved Glu within the RalF Sec7 domain. Furthermore, Arf6 is activated early during infection, with GTP-bound Arf6 localized to the R. typhi entry foci. The regulation of phosphatidylinositol 4-phosphate 5-kinase (PIP5K), which generates PI(4,5)P2, by activated Arf6 is instrumental for bacterial entry, corresponding to the requirement of PI(4,5)P2 for R. typhi entry. PI(3,4,5)P3 is then synthesized at the entry foci, followed by the accumulation of PI(3)P on the short-lived vacuole. Inhibition of phosphoinositide 3-kinases, responsible for the synthesis of PI(3,4,5)P3 and PI(3)P, negatively affects R. typhi infection. Collectively, these results identify RalF as the first bacterial effector to directly activate Arf6, a process that initiates alterations in phosphoinositol metabolism critical for a lineage-specific Rickettsia entry mechanism. PMID:27698019

  20. Molecular and functional analysis of the lepB gene, encoding a type I signal peptidase from Rickettsia rickettsii and Rickettsia typhi.

    PubMed

    Rahman, M Sayeedur; Simser, Jason A; Macaluso, Kevin R; Azad, Abdu F

    2003-08-01

    The type I signal peptidase lepB genes from Rickettsia rickettsii and Rickettsia typhi, the etiologic agents of Rocky Mountain spotted fever and murine typhus, respectively, were cloned and characterized. Sequence analysis of the cloned lepB genes from R. rickettsii and R. typhi shows open reading frames of 801 and 795 nucleotides, respectively. Alignment analysis of the deduced amino acid sequences reveals the presence of highly conserved motifs that are important for the catalytic activity of bacterial type I signal peptidase. Reverse transcription-PCR and Northern blot analysis demonstrated that the lepB gene of R. rickettsii is cotranscribed in a polycistronic message with the putative nuoF (encoding NADH dehydrogenase I chain F), secF (encoding protein export membrane protein), and rnc (encoding RNase III) genes in a secF-nuoF-lepB-rnc cluster. The cloned lepB genes from R. rickettsii and R. typhi have been demonstrated to possess signal peptidase I activity in Escherichia coli preprotein processing in vivo by complementation assay.

  1. Structural properties of lipopolysaccharides from Rickettsia typhi and Rickettsia prowazekii and their chemical similarity to the lipopolysaccharide from Proteus vulgaris OX19 used in the Weil-Felix test.

    PubMed

    Amano, K I; Williams, J C; Dasch, G A

    1998-03-01

    The lipopolysaccharides (LPSs) isolated from typhus group (TG) rickettsiae Rickettsia typhi and Rickettsia prowazekii were characterized by chemical analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by silver staining. LPSs from two species of TG rickettsiae contained glucose, 3-deoxy-D-manno-octulosonic acid, glucosamine, quinovosamine, phosphate, and fatty acids (beta-hydroxylmyristic acid and heneicosanoic acid) but not heptose. The O-polysaccharides of these LPSs were composed of glucose, glucosamine, quinovosamine, and phosphorylated hexosamine. Resolution of these LPSs by their apparent molecular masses by SDS-PAGE showed that they have a common ladder-like pattern. Based on the results of chemical composition and SDS-PAGE pattern, we suggest that these LPSs act as group-specific antigens. Furthermore, glucosamine, quinovosamine, and phosphorylated hexosamine were also found in the O-polysaccharide of the LPS from Proteus vulgaris OX19 used in the Weil-Felix test, suggesting that they may represent the antigens common to LPSs from TG rickettsiae and P. vulgaris OX19.

  2. Survey of ticks collected in Mississippi for Rickettsia, Ehrlichia, and Borrelia species.

    PubMed

    Goddard, Jerome; Sumner, John W; Nicholson, William L; Paddock, Christopher D; Shen, John; Piesman, Joseph

    2003-12-01

    From November 1999 through October 2000, we tested ticks collected from vegetation as well as from deer, dogs, and humans for spotted fever group (SFG) rickettsiae, Ehrlichia chaffeensis, and Borrelia spp. spirochetes. A total of 149 adult ticks representing four species was collected from 11 collection sites from southwestern to northern Mississippi. Amblyomma americanum was most commonly collected (n=68), followed by Ixodes scapularis (n=53). The bird tick, Ixodes brunneus (usually rare), was the third most commonly collected tick (n=17). Eleven Dermacentor variabilis were also collected. Ticks were cut longitudinally to make smears on three microscope slides. The remaining body parts were frozen at -65 degrees C for additional testing. Tick smears were stained by direct immunofluorescence assays (DFA) for Rickettsia spp. and Borrelia spp., while indirect immunofluorescence assays (IFA) were used for Ehrlichia spp. The corresponding tick for each positive smear was evaluated using PCR analysis. None of the 149 ticks tested was DFA positive for Borrelia spp. However, smears of 30 (20%) and 32 (22%) ticks reacted with anti-E. chaffeensis sera and anti-R. rickettsii conjugate (known to react with several members of the spotted fever group), respectively. None of the ticks staining with the IFA for Ehrlichia was positive for E. chaffeensis using PCR. However, 23 (72%) of 32 FA-positive ticks for SFG rickettsiae yielded amplicons of the appropriate size when tested using a PCR assay for SFG rickettsiae, corresponding to an overall infection rate with SFG rickettsiae among the collected ticks of 15%. Smears of 12 (71%) of 17 I. brunneus revealed abundant bacilliform bacteria. PCR amplification of DNA from a single I. brunneus containing these bacteria was performed using universal primers for the 16S rRNA gene as well as Borrelia-specific primers. The predominant sequence obtained using the universal primers did not match any sequence in GenBank, but it showed 91

  3. Implication of the bacterial endosymbiont Rickettsia spp. in interactions of the whitefly Bemisia tabaci with tomato yellow leaf curl virus.

    PubMed

    Kliot, Adi; Cilia, Michelle; Czosnek, Henryk; Ghanim, Murad

    2014-05-01

    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. 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 bacterial load. Our work

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

    PubMed

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

    2013-02-01

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

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

    PubMed

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

    2006-01-01

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

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

    PubMed

    Kubelová, Michaela; Papoušek, Ivo; Bělohlávek, Tomáš; de Bellocq, Joëlle Goüy; Baird, Stuart J E; Široký, Pavel

    2015-09-01

    Spotted fever rickettsioses are tick-borne diseases of growing public health concern. The prevalence of rickettsia-infected ticks and their ability to parasitize humans significantly influence the risk of human infection. Altogether 466 Ixodes ricinus ticks (428 nymphs and 38 larvae) collected from 73 Lacerta schreiberi lizards were examined by PCR targeting the citrate synthetase gene gltA for the presence of Rickettsia spp. Rickettsial DNA was detected in 47% of nymphs and 31.6% of larvae. They were subsequently subjected to a second PCR reaction using primers derived from the outer membrane protein rOmpA encoding gene (ompA) to detect spotted fever group rickettsiae (SFG). This analysis shows that 41.4% of nymphs and 7.9% of larvae collected from the lizards contain DNA of SFG rickettsiae. Sequencing of 43 randomly selected samples revealed two different haplotypes, both closely related to R. monacensis (39 and 4 samples, respectively). The remaining ompA negative Rickettsia spp. samples were determined to be R. helvetica based on sequencing of ompB and gltA fragments. Our results indicate that the role of Iberian endemic lizard L. schreiberi and its ectoparasites in the ecology and epidemiology of zoonotic SFG rickettsioses may be appreciable.

  7. Distribution of Spotted Fever Group Rickettsiae in Hard Ticks (Ixodida: Ixodidae) from Panamanian Urban and Rural Environments (2007-2013).

    PubMed

    Bermúdez, Sergio E; Castro, Angélica M; Trejos, Diomedes; García, Gleydis G; Gabster, Amanda; Miranda, Roberto J; Zaldívar, Yamitzel; Paternina, Luis E

    2016-06-01

    Tick-borne rickettsiosis is an important emerging disease in Panama; to date, there have been 12 confirmed cases, including eight fatalities. To evaluate the distribution of rickettsiae in Panamanian ticks, we collected questing and on-host ticks in urban and rural towns in elevations varying between 0 and 2300 m. A total of 63 sites (13 urban and 50 rural towns) were used to develop models of spatial distributions. We found the following tick species: Rhipicephalus sanguineus s.l. (present in 54 of 63 towns and cities), Amblyomma mixtum (45/63), Dermacentor nitens (40/63), A. ovale (37/63), Rhipicephalus microplus (33/63), A. oblongoguttatum (33/63), Ixodes affinis (3/63), and Ixodes boliviensis (2/63). Rhipicephalus sanguineus s.l. was present in urban and rural towns, and other species were present only in rural towns. DNA was extracted from 408 R. sanguineus s.l., 387 A. mixtum, 103 A. ovale, and 11 A. oblongoguttatum and later tested for rickettsiae genes using PCR. Rickettsia DNA was detected in ticks from 21 of 63 localities. Rickettsia rickettsii was detected in five A. mixtum (1.29%), and Candidatus "Rickettsia amblyommii" was found in 138 A. mixtum (35%), 14 R. sanguineus (3.4%), and one A. ovale (0.9%). These results suggest that much of rural Panama is suitable for the expansion of tick populations and could favor the appearance of new tick-borne rickettsiosis outbreaks.

  8. Novel Rickettsia and emergent tick-borne pathogens: A molecular survey of ticks and tick-borne pathogens in Shimba Hills National Reserve, Kenya.

    PubMed

    Mwamuye, Micky M; Kariuki, Edward; Omondi, David; Kabii, James; Odongo, David; Masiga, Daniel; Villinger, Jandouwe

    2017-02-01

    Ticks are important vectors of emerging and re-emerging zoonoses, the majority of which originate from wildlife. In recent times, this has become a global public health concern that necessitates surveillance of both known and unknown tick-borne pathogens likely to be future disease threats, as well as their tick vectors. We carried out a survey of the diversity of ticks and tick-borne pathogens in Kenya's Shimba Hills National Reserve (SHNR), an area with intensified human-livestock-wildlife interactions, where we collected 4297 questing ticks (209 adult ticks, 586 nymphs and 3502 larvae). We identified four tick species of two genera (Amblyomma eburneum, Amblyomma tholloni, Rhipicephalus maculatus and a novel Rhipicephalus sp.) based on both morphological characteristics and molecular analysis of 16S rRNA, internal transcribed spacer 2 (ITS 2) and cytochrome oxidase subunit 1 (CO1) genes. We pooled the ticks (3-8 adults, 8-15 nymphs or 30 larvae) depending on species and life-cycle stages, and screened for bacterial, arboviral and protozoal pathogens using PCR with high-resolution melting analysis and sequencing of unique melt profiles. We report the first molecular detection of Anaplasma phagocytophilum, a novel Rickettsia-like and Ehrlichia-like species, in Rh. maculatus ticks. We also detected Ehrlichia chaffeensis, Coxiella sp., Rickettsia africae and Theileria velifera in Am. eburneum ticks for the first time. Our findings demonstrate previously unidentified tick-pathogen relationships and a unique tick diversity in the SHNR that may contribute to livestock, and possibly human, morbidity in the region. This study highlights the importance of routine surveillance in similar areas to elucidate disease transmission dynamics, as a critical component to inform the development of better tick-borne disease diagnosis, prevention and control measures.

  9. Silencing urease: A key evolutionary step that facilitated the adaptation of Yersinia pestis to the flea-borne transmission route

    PubMed Central

    Chouikha, Iman; Hinnebusch, B. Joseph

    2014-01-01

    The arthropod-borne transmission route of Yersinia pestis, the bacterial agent of plague, is a recent evolutionary adaptation. Yersinia pseudotuberculosis, the closely related food-and water-borne enteric species from which Y. pestis diverged less than 6,400 y ago, exhibits significant oral toxicity to the flea vectors of plague, whereas Y. pestis does not. In this study, we identify the Yersinia urease enzyme as the responsible oral toxin. All Y. pestis strains, including those phylogenetically closest to the Y. pseudotuberculosis progenitor, contain a mutated ureD allele that eliminated urease activity. Restoration of a functional ureD was sufficient to make Y. pestis orally toxic to fleas. Conversely, deletion of the urease operon in Y. pseudotuberculosis rendered it nontoxic. Enzymatic activity was required for toxicity. Because urease-related mortality eliminates 30–40% of infective flea vectors, ureD mutation early in the evolution of Y. pestis was likely subject to strong positive selection because it significantly increased transmission potential. PMID:25453069

  10. Silencing urease: a key evolutionary step that facilitated the adaptation of Yersinia pestis to the flea-borne transmission route.

    PubMed

    Chouikha, Iman; Hinnebusch, B Joseph

    2014-12-30

    The arthropod-borne transmission route of Yersinia pestis, the bacterial agent of plague, is a recent evolutionary adaptation. Yersinia pseudotuberculosis, the closely related food-and water-borne enteric species from which Y. pestis diverged less than 6,400 y ago, exhibits significant oral toxicity to the flea vectors of plague, whereas Y. pestis does not. In this study, we identify the Yersinia urease enzyme as the responsible oral toxin. All Y. pestis strains, including those phylogenetically closest to the Y. pseudotuberculosis progenitor, contain a mutated ureD allele that eliminated urease activity. Restoration of a functional ureD was sufficient to make Y. pestis orally toxic to fleas. Conversely, deletion of the urease operon in Y. pseudotuberculosis rendered it nontoxic. Enzymatic activity was required for toxicity. Because urease-related mortality eliminates 30-40% of infective flea vectors, ureD mutation early in the evolution of Y. pestis was likely subject to strong positive selection because it significantly increased transmission potential.

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

    PubMed

    Stromdahl, Ellen Y; Jiang, Ju; Vince, Mary; Richards, Allen L

    2011-07-01

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

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

    PubMed

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

    2014-03-01

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

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

    PubMed

    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.

  14. High Prevalence of Rickettsia typhi and Bartonella Species in Rats and Fleas, Kisangani, Democratic Republic of the Congo

    PubMed Central

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

    2014-01-01

    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 cosmopolitan rat species, Rattus rattus and Rattus norvegicus that were infested by a majority of Xenopsylla cheopis fleas. Bartonella queenslandensis, Bartonella elizabethae, and three Bartonella genotypes were identified by sequencing in rat specimens, mostly in R. rattus. Rickettsia typhi was detected in 72% of X. cheopis pools, the main vector and reservoir of this zoonotic pathogen. Co-infections were observed in rodents, suggesting a common mammalian host shared by R. typhi and Bartonella spp. Thus, both infections are endemic in DRC and the medical staffs need to be aware knowing the high prevalence of impoverished populations or immunocompromised inhabitants in this area. PMID:24445202

  15. 35. CARRIE FURNACE No. 6 AND CAST HOUSE. THE CARRIE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. CARRIE FURNACE No. 6 AND CAST HOUSE. THE CARRIE BOILER SHOP IS ON THE RIGHT, IN FRONT OF HOT BLAST STOVES. - U.S. Steel Homestead Works, Blast Furnace Plant, Along Monongahela River, Homestead, Allegheny County, PA

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

    PubMed Central

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

    2013-01-01

    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. PMID:26623321

  17. A survey of antibodies against Rickettsia rickettsii and Ehrlichia chafeensis in domestic animals from a rural area of Colombia.

    PubMed

    Hidalgo, Marylin; Vesga, Juan Fernando; Lizarazo, Diana; Valbuena, Gustavo

    2009-06-01

    In a rural area of Colombia endemic for Rocky Mountain spotted fever, we performed indirect immunofluorescent antibody assays for Rickettsia spp. and Ehrlichia spp. using sera from randomly sampled dogs and horses to test the use of domestic animals as possible sentinels. Antibodies against Ehrlichia spp. were detected in 8 dogs (31.8%). Antibody titers against Rickettsia rickettsii antigen were positive in 4 dogs (18.2%) and 26 horses (16.3%). These values, albeit not directly comparable, are lower than those previously reported for humans in this region. A systemic approach to understanding dynamics of transmission is needed before implementing the use of domestic animals for disease surveillance activities.

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

    PubMed

    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.

  19. Rickettsia amblyommii infecting Amblyomma auricularium ticks in Pernambuco, northeastern Brazil: isolation, transovarial transmission, and transstadial perpetuation.

    PubMed

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

    2013-09-01

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

  20. Cultivation of Rickettsia amblyommii in tick cells, prevalence in Florida lone star ticks (Amblyomma americanum).

    PubMed

    Sayler, Katherine A; Wamsley, Heather L; Pate, Melanie; Barbet, Anthony F; Alleman, A Rick

    2014-06-13

    Rickettsia amblyommii is a bacterium in the spotted fever group of organisms associated with the lone star tick (LST), Amblyomma americanum. The LST is the most commonly reported tick to parasitize humans in the southeastern US. Within this geographic region, there have been suspected cases of Rocky Mountain spotted fever (RMSF) where the causative agent, R. rickettsii, was not identified in the local tick population. In these areas, patients with clinical signs of RMSF had low or no detectable antibodies to R. rickettsii, resulting in an inability to confirm a diagnosis. R. amblyommii was cultivated from host-seeking LSTs trapped in Central Florida and propagated in ISE6 (Ixodes scapularis) and AAE2 (A. americanum) cells. Quantitative PCR targeting the 17-kD gene of Rickettsia spp. identified the genus of the organism in culture. Variable regions of groEL, gtlA and rompA genes were amplified and sequenced to confirm the species. The prevalence of R. amblyommii in LSTs within the geographic region was determined by qPCR followed by conventional PCR and direct sequencing. Analyses of amplified sequences from the cultured organism were 100% homologous to R. amblyommii. The overall prevalence of Rickettsia spp. in the local population of LSTs was 57.1% and rompA sequence analysis identified only R. amblyommii in LSTs. A Florida strain of R. amblyommii was successfully cultivated in two tick cell lines. Further evaluation of the new strain and comparisons to the other geographic strains is needed. The prevalence of this SFG organism in the tick population warrants further investigation into the organism's ability to cause clinical disease in mammalian species.

  1. Genomic and comparative genomic analyses of Rickettsia heilongjiangensis provide insight into its evolution and pathogenesis.

    PubMed

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

    2014-08-01

    Rickettsia heilongjiangensis, the causative agent of far eastern spotted fever, is an obligate intracellular gram-negative bacterium that belongs to the spotted fever group rickettsiae. To understand the evolution and pathogenesis of R. heilongjiangensis, we analyzed its genome and compared it with other rickettsial genomes available in GenBank. The R. heilongjiangensis chromosome contains 1333 genes, including 1297 protein coding genes and 36 RNA coding genes. The genome also contains 121 pseudogenes, 54 insertion sequences, and 39 tandem repeats. Sixteen genes encoding the major components of the type IV secretion systems were identified in the R. heilongjiangensis genome. In total, 37 β-barrel outer membrane proteins were predicted in the genome, eight of which have been previously confirmed to be outer membrane proteins. In addition, 266 potential virulence factor genes, seven partially deleted antibiotic resistance genes, and a genomic island were identified in the genome. The codon usage in the genome is compatible with its low GC content, and the amino acid usage shows apparent bias. A comparative genomic analysis showed that R. heilongjiangensis and R. japonica share one unique fragment that may be a target sequence for a diagnostic assay. The orthologs of 37 genes of R. heilongjiangensis were found in pathogenic R. rickettsii str. Sheila Smith but not in non-pathogenic R. rickettsii str. Iowa, which may explain why R. heilongjiangensis is pathogenic. Pan-genome analysis showed that R. heilongjiangensis and 42 other rickettsiae strains share 693 core genes with a pan-genome size of 4837 genes. The pan-genome-based phylogeny showed that R. heilongjiangensis was closely related to R. japonica.

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

    PubMed Central

    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

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

    PubMed

    Clark, Tina R; Ellison, Damon W; Kleba, Betsy; Hackstadt, Ted

    2011-04-01

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

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

    PubMed

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

    2008-11-01

    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.

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

    PubMed

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

    2011-01-01

    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.

  6. In vitro evaluation of josamycin, spiramycin, and erythromycin against Rickettsia rickettsii and R. conorii.

    PubMed

    Raoult, D; Roussellier, P; Tamalet, J

    1988-02-01

    The antimicrobial activities of josamycin, erythromycin, and spiramycin against Rickettsia conorii and R. rickettsii were evaluated in two tests: a dye-uptake assay and a plaque assay. The MIC of josamycin was 1 microgram/ml for both species; the MICs of erythromycin and spiramycin were 4 to 8 and 16 to 32 micrograms/ml, respectively, for both species. Only josamycin may be of clinical use in treating spotted fever rickettsiosis. It may be useful in treating pregnant women and young children.

  7. On fast carry select adders

    NASA Technical Reports Server (NTRS)

    Shamanna, M.; Whitaker, S.

    1992-01-01

    This paper presents an architecture for a high-speed carry select adder with very long bit lengths utilizing a conflict-free bypass scheme. The proposed scheme has almost half the number of transistors and is faster than a conventional carry select adder. A comparative study is also made between the proposed adder and a Manchester carry chain adder which shows that the proposed scheme has the same transistor count, without suffering any performance degradation, compared to the Manchester carry chain adder.

  8. On fast carry select adders

    NASA Astrophysics Data System (ADS)

    Shamanna, M.; Whitaker, S.

    This paper presents an architecture for a high-speed carry select adder with very long bit lengths utilizing a conflict-free bypass scheme. The proposed scheme has almost half the number of transistors and is faster than a conventional carry select adder. A comparative study is also made between the proposed adder and a Manchester carry chain adder which shows that the proposed scheme has the same transistor count, without suffering any performance degradation, compared to the Manchester carry chain adder.

  9. 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.

    PubMed

    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.

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

    PubMed

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

    2012-01-01

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

  11. Molecular Detection of Rickettsia felis in Different Flea Species from Caldas, Colombia

    PubMed Central

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

    2013-01-01

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

  12. Rickettsia slovaca infection in humans in the northeast of Spain: seroprevalence study.

    PubMed

    Antón, Esperança; Nogueras, Maria Mercedes; Pons, Imma; Font, Bernat; Muñoz, Tomás; Sanfeliu, Isabel; Segura, Ferran

    2008-10-01

    Catalonia is an endemic area of Mediterranean spotted fever. In 1997, A. Lakos described a new tick-borne infectious disease called tick-borne lymphadenopathy. The causative agent is Rickettsia slovaca, which is transmitted by Dermacentor marginatus ticks. We have diagnosed human cases in Catalonia. The objective of this study was to determinate seroprevalence of R. slovaca infection in humans in the northeast of Spain. The population included 217 subjects from Catalonia, northeast of Spain and was stratified by age and living place (rural, suburban, and urban). Age, gender, residence area, contact with animals, occupation, and history of rickettsioses was surveyed. Immunoglobulin G was measured by indirect immunofluorescence assay. Titers >or= 1/40 were considered. Seroprevalence of R. slovaca was 5.5% at titers of 1/40-1/320. Eight (3.7%) sera had antibodies against R. slovaca exclusively. Four sera reacted also against Rickettsia conorii and/or Bar29. Seroprevalence of R. slovaca would range from 3.7% to 5.5%. The only statistically significant association was that between R. slovaca seropositivity and age. We present serologic evidence of R. slovaca infection among population of Catalonia, northeast of Spain.

  13. Birds as potential reservoirs of tick-borne pathogens: first evidence of bacteraemia with Rickettsia helvetica

    PubMed Central

    2014-01-01

    Background Birds have long been known as carriers of ticks, but data from the literature are lacking on their role as a reservoir in the epidemiology of certain tick-borne disease-causing agents. Therefore, the aim of this study was to evaluate the presence of three emerging, zoonotic tick-borne pathogens in blood samples and ticks of birds and to assess the impact of feeding location preference and migration distance of bird species on their tick infestation. Methods Blood samples and ticks of birds were analysed with TaqMan real-time PCRs and conventional PCR followed by sequencing. Results During the spring and autumn bird migrations, 128 blood samples and 140 ticks (Ixodes ricinus, Haemaphysalis concinna and a Hyalomma specimen) were collected from birds belonging to 16 species. The prevalence of tick infestation and the presence of tick species were related to the feeding and migration habits of avian hosts. Birds were shown to be bacteraemic with Rickettsia helvetica and Anaplasma phagocytophilum, but not with Candidatus Neoehrlichia mikurensis. The prevalence of rickettsiae was high (51.4%) in ticks, suggesting that some of them may have acquired their infection from their avian host. Conclusion Based on the present results birds are potential reservoirs of both I. ricinus transmitted zoonotic pathogens, R. helvetica and A. phagocytophilum, but their epidemiological role appears to be less important concerning the latter, at least in Central Europe. PMID:24679245

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

    PubMed

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

    2012-12-01

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

  15. Pathogenic Rickettsia Species Acquire Vitronectin from Human Serum to Promote Resistance to Complement-mediated Killing

    PubMed Central

    Riley, Sean P.; Patterson, Jennifer L.; Nava, Samantha; Martinez, Juan J.

    2014-01-01

    SUMMARY Bacteria of the genus Rickettsia are transmitted from arthropod vectors and primarily infect cells of the mammalian endothelial system. Throughout this infectious cycle, the bacteria are exposed to the deleterious effects of serum complement. Using Rickettsia conorii, the etiologic agent of Mediterranean spotted fever (MSF), as a model rickettsial species, we have previously demonstrated that this class of pathogen interacts with human factor H to mediate partial survival in human serum. Herein, we demonstrate that R. conorii also interacts with the terminal complement complex inhibitor vitronectin (Vn). We further demonstrate that an evolutionarily conserved rickettsial antigen, Adr1/RC1281, interacts with human vitronectin and is sufficient to mediate resistance to serum killing when expressed at the outer-membrane of serum sensitive E. coli. Adr1 is an integral outer-membrane protein whose structure is predicted to contain eight membrane-embedded β-strands and four “loop” regions that are exposed to extracellular milieu. Site-directed mutagenesis of Adr1 revealed that at least two predicted “loop” regions are required to mediate resistance to complement-mediated killing and vitronectin acquisition. These results demonstrate that rickettsial species have evolved multiple mechanisms to evade complement deposition and that evasion of killing in serum is an evolutionarily conserved virulence attribute for this genus of obligate intracellular pathogens. PMID:24286496

  16. Geographic Association of Rickettsia felis-Infected Opossums with Human Murine Typhus, Texas

    PubMed Central

    Boostrom, Ardys; Beier, Magda S.; Macaluso, Jackie A.; Macaluso, Kevin R.; Sprenger, Daniel; Hayes, Jack; Radulovic, Suzan

    2002-01-01

    Application of molecular diagnostic technology in the past 10 years has resulted in the discovery of several new species of pathogenic rickettsiae, including Rickettsia felis. As more sequence information for rickettsial genes has become available, the data have been used to reclassify rickettsial species and to develop new diagnostic tools for analysis of mixed rickettsial pathogens. R. felis has been associated with opossums and their fleas in Texas and California. Because R. felis can cause human illness, we investigated the distribution dynamics in the murine typhus–endemic areas of these two states. The geographic distribution of R. felis-infected opossum populations in two well-established endemic foci overlaps with that of the reported human cases of murine typhus. Descriptive epidemiologic analysis of 1998 human cases in Corpus Christi, Texas, identified disease patterns consistent with studies done in the 1980s. A close geographic association of seropositive opossums (22% R. felis; 8% R. typhi) with human murine typhus cases was also observed. PMID:12023908

  17. Rickettsia Sca4 Reduces Vinculin-Mediated Intercellular Tension to Promote Spread.

    PubMed

    Lamason, Rebecca L; Bastounis, Effie; Kafai, Natasha M; Serrano, Ricardo; Del Álamo, Juan C; Theriot, Julie A; Welch, Matthew D

    2016-10-20

    Spotted fever group (SFG) rickettsiae are human pathogens that infect cells in the vasculature. They disseminate through host tissues by a process of cell-to-cell spread that involves protrusion formation, engulfment, and vacuolar escape. Other bacterial pathogens rely on actin-based motility to provide a physical force for spread. Here, we show that SFG species Rickettsia parkeri typically lack actin tails during spread and instead manipulate host intercellular tension and mechanotransduction to promote spread. Using transposon mutagenesis, we identified surface cell antigen 4 (Sca4) as a secreted effector of spread that specifically promotes protrusion engulfment. Sca4 interacts with the cell-adhesion protein vinculin and blocks association with vinculin's binding partner, α-catenin. Using traction and monolayer stress microscopy, we show that Sca4 reduces vinculin-dependent mechanotransduction at cell-cell junctions. Our results suggest that Sca4 relieves intercellular tension to promote protrusion engulfment, which represents a distinctive strategy for manipulating cytoskeletal force generation to enable spread.

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

    PubMed

    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.

  19. Molecular detection of Rickettsia bellii in Amblyomma rotundatum from imported red-footed tortoise (Chelonoides carbonaria).

    PubMed

    Erster, Oran; Roth, Asael; Avni, Zvi; King, Rony; Shkap, Varda

    2015-06-01

    Introduction of exotic ticks and pathogens through international animal trade (farm animals and pets) is a serious threat to public health and local fauna. Rapid and correct identification of potential threats is an important step on the way to conduct an efficient control of imported pests. In this report we describe the molecular identification of the neotropic tick Amblyomma rotundatum intercepted from red-footed tortoise (Chelonoides carbonaria), imported to Israel from Florida, USA. Molecular analysis of the ticks conducted upon their identification, revealed that they were infected with Rickettsia bellii. Following their collection, the ticks were examined morphologically and five molecular markers were used to determine their taxonomic identity: cytochrome c oxidase subunit 1 (COX1), cytochrome b (CytB), 12S rRNA, 16S rRNA and internal transcribed sequence 2 (ITS-2). Molecular analysis indicated that all of the collected ticks were Amblyomma rotundatum. Using rickettsial gltA (citrate synthase) gene in real-time PCR analysis we found that approximately 25% of the intercepted ticks (8 of 33) were infected with Rickettsia bellii. It is concluded that accurate and timely identification of imported exotic ticks prevented their introduction to Israel, and that use of molecular tools may further improve the response to such potential threats.

  20. A cluster of Rickettsia rickettsii infection at an animal shelter in an urban area of Brazil.

    PubMed

    Rozental, T; Ferreira, M S; Gomes, R; Costa, C M; Barbosa, P R A; Bezerra, I O; Garcia, M H O; Oliveira E Cruz, D M; Galliez, R; Oliveira, S; Brasil, P; Rezende, T; De Lemos, E R S

    2015-08-01

    Rickettsia rickettsii infection is being increasingly recognized as an important cause of fatal acute illness in Brazil, where this tick-borne disease is designated Brazilian spotted fever (BSF). In this study we report five fatal cases of BSF in employees of an animal shelter in an urban area in the municipality of Rio de Janeiro in southeast Brazil after a natural disaster on 11 January 2011. Four of the cases occurred from 27 January to 11 April 2011, while the fifth fatal case was identified in April 2012. Three cases were confirmed by molecular analysis and two by epidemiological linkage. An investigation of BSF was performed in the animal shelter, and blood samples were collected from 115 employees and 117 randomly selected dogs. The presence of high levels (1024-4096) of antibodies against spotted fever group rickettsiae was found in three (2·6%) employees and 114 (97·5%) dogs. These findings emphasize the need to consider BSF as a possible cause of undifferentiated febrile illness, especially dengue and leptospirosis, in patients occupationally exposed to dogs heavily infested by ticks, mainly working at kennels and animal shelters that have inadequate space for the animals housed and frequently providing an environment conducive to exposure to pathogens such as R. rickettsii.

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

    PubMed

    Kleba, Betsy; Clark, Tina R; Lutter, Erika I; Ellison, Damon W; Hackstadt, Ted

    2010-05-01

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

  2. Geographic association of Rickettsia felis-infected opossums with human murine typhus, Texas.

    PubMed

    Boostrom, Ardys; Beier, Magda S; Macaluso, Jacqueline A; Macaluso, Kevin R; Sprenger, Daniel; Hayes, Jack; Radulovic, Suzana; Azad, Abdu F

    2002-06-01

    Application of molecular diagnostic technology in the past 10 years has resulted in the discovery of several new species of pathogenic rickettsiae, including Rickettsia felis. As more sequence information for rickettsial genes has become available, the data have been used to reclassify rickettsial species and to develop new diagnostic tools for analysis of mixed rickettsial pathogens. R. felis has been associated with opossums and their fleas in Texas and California. Because R. felis can cause human illness, we investigated the distribution dynamics in the murine typhus-endemic areas of these two states. The geographic distribution of R. felis-infected opossum populations in two well-established endemic foci overlaps with that of the reported human cases of murine typhus. Descriptive epidemiologic analysis of 1998 human cases in Corpus Christi, Texas, identified disease patterns consistent with studies done in the 1980s. A close geographic association of seropositive opossums (22% R. felis; 8% R. typhi) with human murine typhus cases was also observed.

  3. Human and tick spotted fever group Rickettsia isolates from Israel: a genotypic analysis.

    PubMed Central

    Manor, E; Ighbarieh, J; Sarov, B; Kassis, I; Regnery, R

    1992-01-01

    The genomes of spotted fever group rickettsiae isolated in different geographical areas of Israel (two from ticks and four from humans, obtained over a span of 20 years) were studied by polymerase chain reaction (PCR) and restriction endonuclease fragment length polymorphism (RFLP) analysis. The human isolates were obtained from patients suffering from rickettsial disease of different degrees of severity. The PCR products obtained with five pairs of oligonucleotide primers (two primer sets derived from the 190-kDa polypeptide gene and three from the 120-kDa polypeptide gene) and cleaved with restriction endonucleases were used to study the Israeli isolates and reference Rickettsia conorii isolates. Subtle differences between the PCR-RFLP patterns of Israeli isolates and the two R. conorii reference strains (Moroccan and no. 7) were seen when the PCR products derived from the 190-kDa gene-derived primer sets were digested. All of the Israeli isolates were identical by RFLP analysis using all of the primer sets. This study showed that the Israeli spotted fever group isolates (from both ticks and humans) were genetically homogeneous by the criteria used in this study, despite the time and location differences in their original isolation, and different as a group from R. conorii. Images PMID:1356998

  4. Bartonella and Rickettsia in arthropods from the Lao PDR and from Borneo, Malaysia☆

    PubMed Central

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

    2012-01-01

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

  5. First identification of Rickettsia helvetica in questing ticks from a French Northern Brittany Forest

    PubMed Central

    Paul, Richard E. L.; Bischoff, Emmanuel; Cote, Martine; Le Naour, Evelyne

    2017-01-01

    Tick-borne rickettsiae are considered to be emerging, but data about their presence in western Europe are scarce. Ixodes ricinus ticks, the most abundant and widespread tick species in western Europe, were collected and tested for the presence of several tick-borne pathogens in western France, a region never previously explored in this context. There was a high tick abundance with a mean of 4 females, 4.5 males, and 23.3 nymphs collected per hour per collector. Out of 622 tested ticks, specific PCR amplification showed the presence of tick symbionts as well as low prevalence of Borrelia burgdorferi (0.8%), Bartonella spp. (0.17%), and Anaplasma phagocytophilum (0.09%). The most prevalent pathogen was Rickettsia helvetica (4.17%). This is the first time that this bacteria has been detected in ticks in this region, and this result raises the possibility that bacteria other than those classically implicated may be involved in rickettsial diseases in western France. PMID:28248955

  6. Serological evidence of Rickettsia and Coxiella burnetii in humans of Buenos Aires, Argentina.

    PubMed

    Cicuttin, Gabriel Leonardo; Degiuseppe, Juan Ignacio; Mamianetti, Andrea; Corin, Marcela Viviana; Linares, María Cielo; De Salvo, María Nazarena; Dohmen, Federico Eugenio Gury

    2015-12-01

    In Buenos Aires city (Argentina), the circulation of these agents has been detected mainly in vectors and animals, few human cases having been described. The aim of our study was to determine the seroprevalence of Rickettsia (spotted fever--SFG--and typhus--TG--groups) and Coxiella burnetii (Q fever agent) in residents of Buenos Aires city. The study involved 99 participants. Rickettsia IgG antibodies against SFG and TG were detected by IFA in 28.3% and 16.2% of serum samples, respectively. SFG titers were mostly 1/64 (53.6%) with a maximum of 1/512 (3.5%) whereas TG titers ranged between 1/64 (62.5%) and 1/256 (6.3%). Only one sample showed a titer of 1/32 for C. burnetii (phases I and II). The circulation of these pathogens in urban areas such as the city of Buenos Aires should be considered by health services, especially at the primary care level.

  7. Evidence of antibodies to spotted fever group rickettsiae in small mammals and quail from Mississippi.

    PubMed

    Moraru, Gail Miriam; Goddard, Jerome; Murphy, Alexandria; Link, Diana; Belant, Jerrold L; Varela-Stokes, Andrea

    2013-01-01

    Rickettsia parkeri is a recently recognized human pathogen primarily associated with the Gulf Coast tick Amblyomma maculatum, with immature stages of this tick reported from wild vertebrates. To better understand the role of vertebrates in the natural history of this bacterium, we evaluated small mammals and ground-dwelling birds for evidence of infection with R. parkeri or exposure to the organism. We sampled small mammals (n=39) and passerines (n=47) in both north-central and southeast Mississippi, while northern bobwhite (Colinus virginianus) samples (n=31) were obtained from farms in central Mississippi. Blood from all sampled animals was tested using polymerase chain reaction (PCR) for spotted fever group rickettsiae (SFGR), and for antibodies to SFGR using R. parkeri antigen. Ectoparasite samples were removed from animals and included mites, lice, fleas, and immature ticks. Of 39 small mammal samples collected, 7 were positive for antibodies to SFGR; none tested positive by PCR for DNA of SFGR. Of 47 passerine blood samples collected, none were positive for DNA of SFGR by PCR, nor did any show serological evidence of exposure. Finally, none of 31 northern bobwhite samples tested were positive for SFGR DNA, while 7 were seropositive for rickettsial antibodies. Detection of seropositive rodents and quail suggests a role for these host species in the natural history of SFGR, possibly including R. parkeri, but the extent of their role has not yet been elucidated.

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

    PubMed

    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

    2017-02-09

    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.

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

    PubMed

    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.

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

    PubMed

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

    2006-07-01

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

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

    PubMed Central

    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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2016-04-01

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

  14. Experimental infection of ectoparasitic arthropods with Rickettsia prowazekii (GvF-16 strain) and transmission to flying squirrels.

    PubMed

    Bozeman, F M; Sonenshine, D E; Williams, M S; Chadwick, D P; Lauer, D M; Elisberg, B L

    1981-01-01

    Epizootiologic studies conducted during the past few years showed the existence of widespread natural infection of the southern flying squirrel, Glaucomys volans, with epidemic typhus rickettsiae, Rickettsia prowazekii. The ecological findings strongly implicated transmission of the etiologic agent by an arthropod vector. Studies were conducted under controlled laboratory conditions to determine whether ectoparasites naturally associated with flying squirrels (squirrel fleas, lice, mites and ticks) were capable of acquiring, maintaining and transmitting the infection. Also studied were the cat flea, oriental rat flea and the human body louse. Flying squirrels inoculated with the GvF-16 strain of R. prowazekii circulated rickettsiae in their blood for 2-3 weeks, thus providing ample opportunity for arthropods feeding on them to become infected. The results with Dermacentor variabilis ticks indicated that the rickettsiae did not consistently survive in this insect and were not passed to the eggs of adult females that had been infected subcuticularly. Mites became infected by feeding on infectious blood but failed to sustain the infection. Also, mites fed on an infected flying squirrel did not transmit the infection to a normal squirrel. Squirrel, cat, and oriental rat fleas readily became infected by feeding on a rickettsemic host or on infectious blood through membranes, but failed to transmit the infection to susceptible flying squirrels. In the studies with flying squirrel lice, however, transmission of epidemic typhus from infected to uninfected flying squirrels was demonstrated. Infection of the human body louse with the GvF-16 flying squirrel strain of R. prowazekii was similar to that previously observed with classical human strains, viz., multiplication of the rickettsiae and excretion in the feces.

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

    PubMed

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

    2014-10-01

    The present study was performed in Vila Itoupava, an area of the state of Santa Catarina, southern Brazil, in which a tick-borne spotted fever illness has been endemic since 2003. Notably, both the etiological agent and the vector of these spotted fever cases remain unknown. During January 2011, humans, domestic dogs, and their ticks were sampled in households that are typically surrounded by highly preserved Atlantic rainforest fragments. Ticks collected from dogs were Amblyomma ovale (34% prevalence), Amblyomma aureolatum (18.9%), and Rhipicephalus sanguineus (3.8%). A total of 7.8% (6/77) A. ovale and 9.3% (4/43) A. aureolatum were infected by Rickettsia sp. strain Atlantic rainforest, a Rickettsia parkeri-like agent recently shown to cause spotted fever illness in southeastern Brazil. Overall, 67.3% (35/52) of the dogs were seroreactive to spotted fever group rickettsiae, mostly with highest endpoint titers to R. parkeri. Among humans, 46.7% (7/15) reacted serologically to rickettsiae at low to moderate endpoint titers. Because canine seroreactivity to R. parkeri was strongly associated with frequent contact with forests (the preferred habitat for A. ovale and A. aureolatum), it is concluded that sampled dogs have been infected by strain Atlantic rainforest through the parasitism of these tick species. The present study provides epidemiological evidence that the spotted fever in the study area has been caused by Rickettsia sp. strain Atlantic rainforest, transmitted to humans by either A. ovale or A. aureolatum. Further studies encompassing direct diagnostic methods on clinical specimens from patients are needed to confirm the above epidemiological evidence. Copyright © 2014 Elsevier GmbH. All rights reserved.

  16. [Detection of co-infection with Lyme spirochetes and Spotted fever group rickettsiae in a group of Haemaphysalis longicornis].

    PubMed

    Meng, Zhen; Jiang, Li-ping; Lu, Qun-ying; Cheng, Su-yun; Ye, Ju-lian; Zhan, Li

    2008-12-01

    The present study was conducted to investigate the infection of Lyme disease, Spotted fever, Ehrlichiosis (anaplasmosisin) in wild animals and ticks in the mountain areas of Zhejiang province. Nested polymerase chain reaction was used to amplify specific DNA sequences of Lyme spirochetes, Spotted fever group rickettsiae, Ehrlichia(anaplasma) from samples of mice and ticks. 14 positive samples were identified from 121 mice and 105 groups of ticks. Among mice samples, one positive 5S-23S rDNA intergenic spacer of Borrelia burgdorferi and two 5' fragments of Ehrlichia (anaplasma) 16S rDNA were obtained. 11 positive results were detected from tick samples including three 5S-23S rDNA intergenic spacer regions of Borrelia burgdorferi and eight 5' fragments of Spotted fever group rickettsiae outer member protein A gene. One group of adult ticks, Haemaphysalis longicornis, which had been collected from eastern mountain area were detected to have co-infected with Lyme spirochetes and Spotted fever group rickettsiae. The positive sequences of 5S-23S rDNA intergenic spacer and ompA gene were tested and analyzed as Lyme spirochetes while rickettsia which was closely related to Borrelia valaisiana and R. massiliae. This was the first report about co-infection of Lyme spirochetes and Spotted fever group rickettsiae found in the same group of adult Haemaphysalis longicornis. It is very important to strengthen the surveillance program on tick-borne infectious disease and their pathogenic in vectors, wild animals and targeted high risk groups and to differentiate the clinical manifestation and diagnosis to extend the knowledge of tick-borne infectious diseases in Zhejiang.

  17. Molecular Detection of Rickettsia typhi in Cats and Fleas

    PubMed Central

    Nogueras, Maria Mercedes; Pons, Immaculada; Ortuño, Ana; Miret, Jaime; Pla, Julia; Castellà, Joaquim; Segura, Ferran

    2013-01-01

    Background Rickettsiatyphi is the etiological agent of murine typhus (MT), a disease transmitted by two cycles: rat-flea-rat, and peridomestic cycle. Murine typhus is often misdiagnosed and underreported. A correct diagnosis is important because MT can cause severe illness and death. Our previous seroprevalence results pointed to presence of human R. typhi infection in our region; however, no clinical case has been reported. Although cats have been related to MT, no naturally infected cat has been described. The aim of the study is to confirm the existence of R. typhi in our location analyzing its presence in cats and fleas. Methodology/Principal Findings 221 cats and 80 fleas were collected from Veterinary clinics, shelters, and the street (2001-2009). Variables surveyed were: date of collection, age, sex, municipality, living place, outdoor activities, demographic area, healthy status, contact with animals, and ectoparasite infestation. IgG against R. typhi were evaluated by indirect immunofluorescence assay. Molecular detection in cats and fleas was performed by real-time PCR. Cultures were performed in those cats with positive molecular detection. Statistical analysis was carried out using SPSS. A p < 0.05 was considered significant. Thirty-five (15.8%) cats were seropositive. There were no significant associations among seropositivity and any variables. R. typhi was detected in 5 blood and 2 cultures. High titres and molecular detection were observed in stray cats and pets, as well as in spring and winter. All fleas were Ctenocephalides felis. R. typhi was detected in 44 fleas (55%), from shelters and pets. Co-infection with R. felis was observed. Conclusions Although no clinical case has been described in this area, the presence of R. typhi in cats and fleas is demonstrated. Moreover, a considerable percentage of those animals lived in households. To our knowledge, this is the first time R. typhi is detected in naturally infected cats. PMID:23940746

  18. Rickettsial phospholipase A2 as a pathogenic mechanism in a model of cell injury by typhus and spotted fever group rickettsiae.

    PubMed

    Walker, D H; Feng, H M; Popov, V L

    2001-12-01

    Phospholipase A2 activity by typhus group rickettsiae causes hemolysis in vitro. Rickettsial phospholipase A2 has been proposed to mediate entry into the host cell, escape from the phagosome, and cause injury to host cells by both typhus and spotted fever group rickettsiae. In a rickettsial contact-associated cytotoxicity model, the interaction of Rickettsia prowazekii or R. conorii with Vero cells caused temperature-dependent release of 51Cr from the cells. Treatment of rickettsiae, but not the cells, with a phospholipase A2 inhibitor (bromophenacyl bromide) or with antibody to king cobra venom inhibited cell injury. Rickettsial treatment with bromophenacyl bromide inhibited the release of free fatty acids from the host cell. Neither the inhibitor nor antivenom impaired rickettsial active transport of L-lysine. Thus, host cell injury was mediated by a rickettsial phospholipase A2-dependent mechanism.

  19. 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.

    PubMed

    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.

  20. Proteolytic Cleavage of the Immunodominant Outer Membrane Protein rOmpA in Rickettsia rickettsii.

    PubMed

    Noriea, Nicholas F; Clark, Tina R; Mead, David; Hackstadt, Ted

    2017-03-15

    Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, contains two immunodominant proteins, rOmpA and rOmpB, in the outer membrane. Both rOmpA and rOmpB are conserved throughout spotted fever group rickettsiae as members of a family of autotransporter proteins. Previously, it was demonstrated that rOmpB is proteolytically processed, with the cleavage site residing near the autotransporter domain at the carboxy-terminal end of the protein, cleaving the 168-kDa precursor into apparent 120-kDa and 32-kDa fragments. The 120- and 32-kDa fragments remain noncovalently associated on the surface of the bacterium, with implications that the 32-kDa fragment functions as the membrane anchor domain. Here we present evidence for a similar posttranslational processing of rOmpA. rOmpA is expressed as a predicted 224-kDa precursor yet is observed on SDS-PAGE as a 190-kDa protein. A small rOmpA fragment of ∼32 kDa was discovered during surface proteome analysis and identified as the carboxy-terminal end of the protein. A rabbit polyclonal antibody was generated to the autotransporter region of rOmpA and confirmed a 32-kDa fragment corresponding to the calculated mass of a proteolytically cleaved rOmpA autotransporter region. N-terminal amino acid sequencing revealed a cleavage site on the carboxy-terminal side of Ser-1958 in rOmpA. An avirulent strain of R. rickettsii Iowa deficient in rOmpB processing was also defective in the processing of rOmpA. The similarities of the cleavage sites and the failure of R. rickettsii Iowa to process either rOmpA or rOmpB suggest that a single enzyme may be responsible for both processing events.IMPORTANCE Members of the spotted fever group of rickettsiae, including R. rickettsii, the etiologic agent of Rocky Mountain spotted fever, express at least four autotransporter proteins that are protective antigens or putative virulence determinants. One member of this class of proteins, rOmpB, is proteolytically processed to a

  1. Antibodies to Rickettsia rickettsii, Rickettsia typhi, Coxiella burnetii, Bartonella henselae, Bartonella quintana, and Ehrlichia chaffeensis among healthy population in Minas Gerais, Brazil.

    PubMed

    da Costa, Paulo Sérgio Gonçalves; Brigatte, Marcos Emilio; Greco, Dirceu Bartolomeu

    2005-12-01

    Rickettsial diseases except those belonging to spotted fever group rickettsioses are poorly studied in South America particularly in Brazil where few epidemiological reports have been published. We describe a serosurvey for Rickettsia rickettsii, R. typhi, Coxiella burnetii, Bartonella henselae, B. quintana, and Ehrlichia chaffeensis in 437 healthy people from a Brazilian rural community. The serum samples were tested by indirected micro-immunoflourescence technique and a cutoff titer of 1:64 was used. The seroprevalence rates for R. rickettsii, R. typhi, C. burnetii, B. henselae, B. quintana, and E. chaffeensis were respectively 1.6% (7 samples); 1.1% (5 samples); 3.9% (17 samples); 13.7% (60 samples); 12.8% (56 samples), and 10.5% (46 samples). Frequent multiple/cross-reactivity was observed in this study. Age over 40 years old, urban profession, and rural residence were significantly associated with some but not all infections rate. Low seropositivity rates for R. rickettsii, R. typhi, and C. burnetii contrasted with higher rates of seropositivity for B. quintana, B. henselae, and E. chaffeensis. These results show that all tested rickettsial species or antigenically closely related possible exist in this particular region.

  2. THE EFFECTS OF X-RAYS AND BETA RAYS (TRITIUM) ON THE GROWTH OF RICKETTSIA MOOSERI AND RICKETTSIA AKARI IN EMBRYONATE EGGS

    PubMed Central

    Greiff, Donald; Powers, E. L.; Kisieleski, Walter E.; Pinkerton, Henry

    1960-01-01

    The growth of Rickettsia mooseri was accelerated and quantitatively increased in embryonate eggs containing tritium oxide at levels of 180, 90, and 45 mc./egg during the growth period. The eggs of a group containing 22.5 mc./egg showed only a slight increase in the rate of growth of organisms; the infections in the eggs of a group given 11.2 mc./egg did not differ significantly from those of the control group. On the other hand, growth of R. akari was inhibited in embryonate eggs containing tritium oxide at levels of 180, 90, and 45 mc./egg, and partially inhibited in groups containing 22.5 and 11.2 mc./egg. The patterns of growth of R. mooseri and of R. akari exposed to tritium oxide for 6 hours prior to inoculation into embryonate eggs did not differ significantly from that of the control group. Single and divided doses of x-rays to the host resulted in partial inhibition of the growth of R. akari. PMID:13708436

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

    PubMed Central

    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. PMID:25923891

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

    PubMed Central

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

    2014-01-01

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

  5. Fluorescence Activated Cell Sorting of Rickettsia prowazekii-Infected Host Cells Based on Bacterial Burden and Early Detection of Fluorescent Rickettsial Transformants

    PubMed Central

    Driskell, Lonnie O.; Tucker, Aimee M.; Woodard, Andrew; Wood, Raphael R.; Wood, David O.

    2016-01-01

    Rickettsia prowazekii, the causative agent of epidemic typhus, is an obligate intracellular bacterium that replicates only within the cytosol of a eukaryotic host cell. Despite the barriers to genetic manipulation that such a life style creates, rickettsial mutants have been generated by transposon insertion as well as by homologous recombination mechanisms. However, progress is hampered by the length of time required to identify and isolate R. prowazekii transformants. To reduce the time required and variability associated with propagation and harvesting of rickettsiae for each transformation experiment, characterized frozen stocks were used to generate electrocompetent rickettsiae. Transformation experiments employing these rickettsiae established that fluorescent rickettsial populations could be identified using a fluorescence activated cell sorter within one week following electroporation. Early detection was improved with increasing amounts of transforming DNA. In addition, we demonstrate that heterogeneous populations of rickettsiae-infected cells can be sorted into distinct sub-populations based on the number of rickettsiae per cell. Together our data suggest the combination of fluorescent reporters and cell sorting represent an important technical advance that will facilitate isolation of distinct R. prowazekii mutants and allow for closer examination of the effects of infection on host cells at various infectious burdens. PMID:27010457

  6. High prevalence of Rickettsia africae variants in Amblyomma variegatum ticks from domestic mammals in rural western Kenya: implications for human health.

    PubMed

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

    2014-10-01

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

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

    PubMed

    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.

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

    PubMed Central

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

    1989-01-01

    A polymerase chain reaction (PCR) procedure for detecting rickettsial DNA was developed and shown to be specific for Rickettsia rickettsii and R. conorii, the etiologic agents of Rocky Mountain spotted fever (RMSF) and Boutonneuse fever, respectively. Blood clots were obtained from nine confirmed RMSF patients and six controls and analyzed for the presence of rickettsial DNA by the PCR method. A defined region of the rickettsial genome was successfully amplified from seven of the nine clinical specimens tested; all six control specimens gave negative results. These findings indicate that R. rickettsii can be detected early after the onset of RMSF, possibly facilitating the decision regarding appropriate antibiotic therapy for some patients. Further refinement of PCR technology could make this procedure a mainstay in the clinical laboratory. Images PMID:2512328

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

    PubMed

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

    2014-04-01

    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.

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

    PubMed Central

    Saraiva, Danilo G.; Soares, Herbert S.; Soares, João Fábio

    2014-01-01

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

  11. Rickettsia felis in Ctenocephalides felis felis from Five Geographic Regions of Brazil

    PubMed Central

    Horta, Mauricio C.; Ogrzewalska, Maria; Azevedo, Milka C.; Costa, Francisco B.; Ferreira, Fernando; Labruna, Marcelo B.

    2014-01-01

    This study evaluated rickettsial infection in 701 Ctenocephalides felis felis fleas that were collected from dogs and cats in 31 municipalities, encompassing all regions and major biomes of Brazil. A total of 268 (38.2%) fleas from 30 municipalities were polymerase chain reaction (PCR) positive for the rickettsial gltA gene. The PCR products from 44 fleas, consisting of at least 1 PCR-positive flea from each of 30 municipalities, generated DNA sequences identical to Rickettsia felis. Rickettsial prevalence was highly variable among 30 municipalities, with values ranging from 2.9% to 100%. Significantly higher infection rates by R. felis were associated with the Pampa biome (southern Brazil), and the temperate climate that prevails in southern Brazil. In contrast, lowest R. felis-infection rates were significantly associated with the Caatinga biome, and its semiarid climate. Further studies should evaluate the effect of temperature and moisture on the R. felis infection in Ctenocephalides fleas world widely. PMID:24778194

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

    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.

    2014-01-01

    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. PMID:24957541

  14. [Fever and vesiculopapular exanthema due to infection with Rickettsia africae after a sojourn in South Africa].

    PubMed

    Kager, P A; Dondorp, A M

    2001-01-20

    A 26-year-old woman, who had visited the Krugerpark in South Africa 5 days before, presented with fever, a skin lesion with a black crust (eschar), lymphadenopathy and a vesiculo papular rash. The clinical diagnosis 'Rickettsia africae infection' was confirmed by specific serological tests. A second patient aged 43 years, whose vesicular rash did not respond to flucloxacillin had been in the Krugerpark one week before and on examination was found with 2 eschars. Based on epidemiological and clinical grounds African tick fever can be distinguished from Mediterranean spotted fever (fièvre boutonneuse). In the Netherlands specific diagnostic tests are not available. For treatment the distinction is not necessary; treatment is with tetracycline or doxycycline. Both patients recovered upon this treatment.

  15. A confirmed case of Rickettsia parkeri infection in a traveler from Uruguay.

    PubMed

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

    2013-12-01

    The first confirmed case of Rickettsia parkeri infection in Uruguay is reported. To date, in South America, molecularly confirmed cases of human infection have been found in Argentina and probably, Brazil. Our patient returned to Spain after a 7-day trip to Colonia Suiza (Southwestern Uruguay). He presented fever (39°C), chills, and two eschars (tache noire-like) surrounded by an indurated, erythematous halo on the inner side of the left ankle besides a maculopapular rash on the legs. After treatment with doxycycline for 7 days, he fully recovered. R. parkeri infection was diagnosed by molecular-based detection of the microorganism in a swab specimen of the eschar. Diagnosis was supported by seroconversion between acute- and convalescent-phase sera specimens.

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

    PubMed Central

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

    2013-01-01

    The first confirmed case of Rickettsia parkeri infection in Uruguay is reported. To date, in South America, molecularly confirmed cases of human infection have been found in Argentina and probably, Brazil. Our patient returned to Spain after a 7-day trip to Colonia Suiza (Southwestern Uruguay). He presented fever (39°C), chills, and two eschars (tache noire-like) surrounded by an indurated, erythematous halo on the inner side of the left ankle besides a maculopapular rash on the legs. After treatment with doxycycline for 7 days, he fully recovered. R. parkeri infection was diagnosed by molecular-based detection of the microorganism in a swab specimen of the eschar. Diagnosis was supported by seroconversion between acute- and convalescent-phase sera specimens. PMID:24166040

  17. Structure of RC1339/APRc from Rickettsia conorii, a retropepsin-like aspartic protease

    PubMed Central

    Li, Mi; Gustchina, Alla; Cruz, Rui; Simões, Marisa; Curto, Pedro; Martinez, Juan; Faro, Carlos; Simões, Isaura; Wlodawer, Alexander

    2015-01-01

    The crystal structures of two constructs of RC1339/APRc from Rickettsia conorii, consisting of either residues 105–231 or 110–231 followed by a His tag, have been determined in three different crystal forms. As predicted, the fold of a monomer of APRc resembles one-half of the mandatory homodimer of retroviral pepsin-like aspartic proteases (retropepsins), but the quaternary structure of the dimer of APRc differs from that of the canonical retropepsins. The observed dimer is most likely an artifact of the expression and/or crystallization conditions since it cannot support the previously reported enzymatic activity of this bacterial aspartic protease. However, the fold of the core of each monomer is very closely related to the fold of retropepsins from a variety of retroviruses and to a single domain of pepsin-like eukaryotic enzymes, and may represent a putative common ancestor of monomeric and dimeric aspartic proteases. PMID:26457434

  18. Feeding period required by Amblyomma aureolatum ticks for transmission of Rickettsia rickettsii to vertebrate hosts.

    PubMed

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

    2014-09-01

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

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

    PubMed

    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

    2012-11-01

    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.

  20. Spotted fever group rickettsiae in ticks from the Masai Mara region of Kenya.

    PubMed

    Macaluso, Kevin R; Davis, Jon; Alam, Uzma; Korman, Amy; Rutherford, Jeremiah S; Rosenberg, Ronald; Azad, Abdu F

    2003-05-01

    We have identified for the first time Rickettsia africae, and the ticks that harbored them, in Kenya. A total of 5,325 ticks were collected from vegetation, livestock, and wild animals during two field trips to southwestern Kenya. Most were immature forms (85.2%) belonging to the genera Amblyomma or Rhipicephalus. The adults also included representatives from the genus Boophilus. Ticks were assessed for rickettsial DNA by a polymerase chain reaction (PCR) using primers for the spotted fever group (SFG)-specific rickettsial outer membrane protein A (rompA) gene, and positive amplicons were sequenced. While none of the immature ticks tested positive by PCR, 15.8% of the adult Amblyomma variegatum and less than 1% of the Rhipicephalus spp. were SFG positive. Sequences of amplified products were identified as R. africae. These findings extend the known range of R. africae.

  1. [Diseases caused by bacteria and rickettsia in biological warfare and bioterrorism].

    PubMed

    Bojić, Ivanko; Vukadinov, Jovan; Minić, Svetlana

    2007-01-01

    Until recently, the use of biological weapons was considered more from an academic than practical point of view. The list of agents and/or toxins that can be used as biological weapons is long. Some of them are highly lethal, while others cause morbidity and disability. Bacteria, rickettsia, viruses, fungi, protozoa and toxins can all be used as biological weapons. The infection may be acquired by inhalation of aerosols, ingestion of contaminated water or food or direct contact with infectious agents. Early recognition, diagnosis and treatment of these patients is of utmost importance. Special attention must be given to the use of genetically modified microorganisms. Medical protection from biological weapons is very important as well as continuous education. This article describes the main clinical characteristics of anthrax, cholera, plague, Q fever, tularemia, brucellosis, and glanders, as biological weapons, their diagnostics, treatment and basic prevention measures.

  2. A case of uveitis due to Rickettsia conorii infection in Southeastern France.

    PubMed

    Caisso, Cecile; Payan, Jacques; Dunais, Brigitte; Neri, Dominique; Vassallo, Matteo

    2016-03-01

    We describe a case of skin rash and bilateral uveitis secondary to Rickettsia conorii infection. A 60-year-old female patient, living in the rural hinterland of Cannes, was referred to our hospital in mid-August 2012 for skin rash, fever, and arthromyalgia. Blood tests showed increased inflammatory markers, hepatic cytolysis and anicteric cholestasis. Ophthalmic examination revealed bilateral papillitis and focal chorio-retinitis. Fluoroscopic angiography demonstrated early hypofluorescence, with a few arteriolar occlusions, and subsequent hyperfluorescence and focal vasculitis. R. conorii antibodies were identified by immunofluorescence antibody test. Investigation of other infective agents and the immunological panel were negative. A 2-week course of doxycycline 200 mg/day was prescribed, and fever rapidly subsided, the skin rash resolved and vision improved. Ophthalmic examination a month and a half later showed almost all retinal lesions had disappeared and inflammation markers had returned to normal. Copyright © 2015 Elsevier GmbH. All rights reserved.

  3. First report of "Candidatus Rickettsia amblyommii" in west coast of Mexico.

    PubMed

    Sánchez-Montes, Sokani; Ríos-Muñoz, César A; Espinosa-Martínez, Deborah V; Guzmán-Cornejo, Carmen; Berzunza-Cruz, Miriam; Becker, Ingeborg

    2016-10-01

    We report the first case of "Candidatus Rickettsia amblyommii" detected in Amblyomma mixtum ticks on humans on the west coast of Mexico. This is the most western record of "Ca. R. amblyommii" in the Western Hemisphere, representing the first record for the western coast of the Americas. Even if the record is far from the previously known locations for the species it does not represent a new record regarding temperature, precipitation and topographic parameters. Since "Ca. R. amblyommii" antibodies have been detected in patients suspected of Rocky Mountain spotted fever, and the tick A. mixtum has been associated with humans, it is important to consider "Ca. R. amblyommii" as a potential risk for the human population that has not been considered at risk before.

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

    PubMed

    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.

  5. Experimental infection of Rhipicephalus sanguineus ticks with the bacterium Rickettsia rickettsii, using experimentally infected dogs.

    PubMed

    Piranda, Eliane M; Faccini, João Luiz H; Pinter, Adriano; Pacheco, Richard C; Cançado, Paulo H D; Labruna, Marcelo B

    2011-01-01

    We evaluated if Rickettsia rickettsii-experimentally infected dogs could serve as amplifier hosts for hipicephalus sanguineus ticks. In addition, we checked if Rh. sanguineus ticks that acquired Ri. rickettsii from dogs could transmit the bacterium to susceptible hosts (vector competence), and if these ticks could maintain the bacterium by transstadial and transovarial transmissions. Uninfected larvae, nymphs, and adults of Rh. sanguineus were allowed to feed upon three groups of dogs: groups 1 (G1) and 2 (G2) composed of Ri. rickettsii-infected dogs, infected intraperitoneally and via tick bites, respectively, and group 3 composed of uninfected dogs. After larval and nymphal feeding on rickettsemic dogs, 7.1-15.2% and 35.8-37.9% of the molted nymphs and adults, respectively, were shown by polymerase chain reaction (PCR) to be infected by Ri. rickettsii, confirming that both G1 and G2 dogs were efficient sources of rickettsial infection (amplifier host), resulting in transstadial transmission of the agent. These infected nymphs and adults successfully transmitted Ri. rickettsii to guinea pigs, confirming vector competence after acquisition of the infection from rickettsemic dogs. Transovarial transmission of Ri. rickettsii was observed in engorged females that had been infected as nymphs by feeding on both G1 and G2 dogs, but not in engorged females that acquired the infection during adult feeding on these same dogs. In the first case, filial infection rates were generally <50%. No tick exposed to G3 dogs was infected by rickettsiae in this study. No substantial mortality difference was observed between Ri. rickettsii-infected tick groups (G1 and G2) and uninfected tick group (G3). Our results indicate that dogs can be amplifier hosts of Ri. rickettsii for Rh. sanguineus, although only a minority of immature ticks (<45%) should become infected. It appears that Rh. sanguineus, in the absence of horizontal transmission, would not maintain Ri. rickettsii through

  6. TolC-dependent secretion of an ankyrin repeat-containing protein of Rickettsia typhi.

    PubMed

    Kaur, Simran J; Rahman, M Sayeedur; Ammerman, Nicole C; Beier-Sexton, Magda; Ceraul, Shane M; Gillespie, Joseph J; Azad, Abdu F

    2012-09-01

    Rickettsia typhi, the causative agent of murine (endemic) typhus, is an obligate intracellular pathogen with a life cycle involving both vertebrate and invertebrate hosts. In this study, we characterized a gene (RT0218) encoding a C-terminal ankyrin repeat domain-containing protein, named Rickettsia ankyrin repeat protein 1 (RARP-1), and identified it as a secreted effector protein of R. typhi. RT0218 showed differential transcript abundance at various phases of R. typhi intracellular growth. RARP-1 was secreted by R. typhi into the host cytoplasm during in vitro infection of mammalian cells. Transcriptional analysis revealed that RT0218 was cotranscribed with adjacent genes RT0217 (hypothetical protein) and RT0216 (TolC) as a single polycistronic mRNA. Given one of its functions as a facilitator of extracellular protein secretion in some Gram-negative bacterial pathogens, we tested the possible role of TolC in the secretion of RARP-1. Using Escherichia coli C600 and an isogenic tolC insertion mutant as surrogate hosts, our data demonstrate that RARP-1 is secreted in a TolC-dependent manner. Deletion of either the N-terminal signal peptide or the C-terminal ankyrin repeats abolished RARP-1 secretion by wild-type E. coli. Importantly, expression of R. typhi tolC in the E. coli tolC mutant restored the secretion of RARP-1, suggesting that TolC has a role in RARP-1 translocation across the outer membrane. This work implies that the TolC component of the putative type 1 secretion system of R. typhi is involved in the secretion process of RARP-1.

  7. Prevalence of antibodies against Rickettsia conorii, Babesia canis, Ehrlichia canis, and Anaplasma phagocytophilum antigens in dogs from the Stretto di Messina area (Italy).

    PubMed

    Pennisi, Maria-Grazia; Caprì, Alessandra; Solano-Gallego, Laia; Lombardo, Gabriella; Torina, Alessandra; Masucci, Marisa

    2012-12-01

    The aims of this study were to determine the seroprevalence for Rickettsia conorii, Ehrlichia canis, Anaplasma phagocytophilum, and Babesia canis in outdoor-kennelled dogs (n=249) from the Stretto di Messina (Italy) and to compare seroprevalence in 2 public shelters and 4 privately-owned kennels where different tick-preventive measures were implemented in order to focus on the specific sanitary risk posed by public shelters in southern Italy for tick-borne pathogens. R. conorii (72%) and B. canis (70%) were the most prevalent infections when compared to E. canis (46%) and A. phagocytophilum (38%). Seroprevalence for R. conorii, E. canis, and A. phagocytophilum was significantly higher in public shelters than in private kennels. However, B. canis seropositivity was similar in both types of kennels. In addition, in private kennels where a regular ectocide treatment was carried out by means of spot-on devices, dogs did not present E. canis and A. phagocytophilum antibodies. One hundred fifty-one dogs out of 249 (61%) were seropositive to more than one pathogen with R. conorii and B. canis the most common ones. Coinfections were more frequently found in public-shelter dogs. This study demonstrated high seroprevalences against R. conorii, B. canis, E. canis, and A. phagocytophilum in kennelled dogs from both coastal sites of the Stretto di Messina and the importance of regular tick-bite prevention by means of individual spot-on devices.

  8. Carry Groups: Abstract Algebra Projects

    ERIC Educational Resources Information Center

    Miller, Cheryl Chute; Madore, Blair F.

    2004-01-01

    Carry Groups are a wonderful collection of groups to introduce in an undergraduate Abstract Algebra course. These groups are straightforward to define but have interesting structures for students to discover. We describe these groups and give examples of in-class group projects that were developed and used by Miller.

  9. Carry Groups: Abstract Algebra Projects

    ERIC Educational Resources Information Center

    Miller, Cheryl Chute; Madore, Blair F.

    2004-01-01

    Carry Groups are a wonderful collection of groups to introduce in an undergraduate Abstract Algebra course. These groups are straightforward to define but have interesting structures for students to discover. We describe these groups and give examples of in-class group projects that were developed and used by Miller.

  10. Identification of Rickettsia africae and Wolbachia sp. in Ceratophyllus garei Fleas from Passerine Birds Migrated from Africa

    PubMed Central

    Sekeyová, Zuzana; Mediannikov, Oleg; Roux, Véronique; Subramanian, Geetha; Špitalská, Eva; Kristofík, Jano; Darolová, Alžbeta

    2012-01-01

    Abstract The aim of the study was to reveal new aspects of the role of flea vector taken from migratory birds by screening of specimens with molecular biological methods. A field study was done in fishponds in Slovakia. Actually, 47 fleas were collected from reed warblers (Acrocephalus scirpaceus) and their nests. DNA was extracted and analyzed for representatives of the orders Rickettsiales. A rickettsia that shares 99.7% of identity by gltA gene with Rickettsia africae was identified in Ceratophyllus garei collected from A. scirpaceus. Moreover, two Wolbachia sp. were also detected in fleas. This is the first record of R. africae and Wolbachia sp. identified so far in Central Europe in fleas collected from migratory bird returning from Africa. This molecular study extends the geographic range and vector spectrum of arthropod-borne agents. PMID:22448745

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

    PubMed

    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.

  12. Natural history of tick-borne spotted fever in the USA. Susceptibility of small mammals to virulent Rickettsia rickettsii.

    PubMed

    Burgdorfer, W; Friedhoff, K T; Lancaster, J L

    1966-01-01

    In the ecology of spotted fever rickettsiae, one of the as yet unsolved problems concerns the significance of small animals in the distribution of Rickettsia rickettsii in nature. In the Bitter Root Valley of western Montana, a great variety of rodents, rabbits and hares are known to serve as the preferred hosts for the immature stages of the vector tick, Dermacentor andersoni.The authors analyse the susceptibility of various species of small mammals to virulent R. rickettsii and evaluate their efficiency as sources of infection for larval ticks. The results demonstrate that meadow-mice, Columbian ground-squirrels, golden-mantled ground-squirrels, chipmunks and snowshoe hares (the latter to a lesser extent), when bitten by infected ticks, respond with rickettsiaemias of sufficient length and degree to infect normal larval D. andersoni. High infection rates were obtained in ticks that fed during periods of high rickettsial concentrations in the blood.

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

    PubMed

    Lamas, Cristiane; Favacho, Alexsandra; Rozental, Tatiana; Bóia, Márcio N; Kirsten, Andrei H; Guterres, Alexandro; Barreira, Jairo; de Lemos, Elba Regina S

    2008-04-01

    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.

  14. Detection of Rickettsia tamurae DNA in ticks and wild boar (Sus scrofa leucomystax) skins in Shimane Prefecture, Japan.

    PubMed

    Motoi, Yuta; Asano, Makoto; Inokuma, Hisashi; Ando, Shuji; Kawabata, Hiroki; Takano, Ai; Suzuki, Masatsugu

    2013-01-01

    We used 24 wild boars trapped from December 2009 to January 2010 and a further 65 from July 2010 to August 2010 in Misato Town, Shimane Prefecture, Japan. We collected blood, spleens, skins and ticks from the wild boars, which were examined for rickettsial infections using polymerase chain reaction (PCR) primers for the genes rickettsial 17-kDa antigen and citrate synthase (gltA). We amplified Rickettsia tamurae AT-1 DNA from the tick Amblyomma testudinarium and from wild boar skins where ticks attached. Antibodies against spotted fever group Rickettsia were detected in wild boar sera using immunofluorescence, whereas blood and spleen samples contained no rickettsial DNA. This study suggests that wild boars have a role as an amplifier and a transporter of A. testudinarium, which harbor R. tamurae. One case of R. tamurae infection in humans was reported in Shimane Prefecture. Therefore, R. tamurae infections in humans might increase, if wild boar populations and their habitats expand.

  15. Bartonella and Rickettsia from fleas (Siphonaptera: Ceratophyllidae) of prairie dogs (Cynomys spp.) from the western United States.

    PubMed

    Reeves, Will K; Rogers, Thomas E; Dasch, Gregory A

    2007-08-01

    Fleas of prairie dogs have been implicated in the transmission of Bartonella spp. We used PCR to test DNA extracts from 47 fleas of prairie dogs from 6 states. We amplified DNA from 5 unique genotypes of Bartonella spp. and 1 Rickettsia sp. from 12 fleas collected in North Dakota, Oklahoma, Texas, and Wyoming. Sequences from the Bartonella spp. were similar, but not identical, to those from prairie dogs and their fleas in Colorado.

  16. Rickettsia parkeri as a paradigm for multiple causes of tick-borne spotted fever in the western hemisphere.

    PubMed

    Paddock, Christopher D

    2005-12-01

    Among the many contributions made to rickettsiology by entomologist and rickettsiologist Ralph R. Parker was his discovery in 1937 of a novel rickettsia isolated from the Gulf Coast tick, Amblyomma maculatum. This bacterium was subsequently characterized as a unique rickettsial species in 1965 and named Rickettsia parkeri in honor of its discoverer. During the next several decades R. parkeri was generally considered as one of several "nonpathogenic" spotted fever group (SFG) rickettsiae that resided in ticks of the United States. The identification of novel rickettsioses on other continents during the last two decades of the twentieth century provided important evidence of the frequent coexistence of multiple and unique tick-borne SFG rickettsiae sharing common geographic regions. Surprisingly, this paradigm, which was repeatedly demonstrated in Europe, Africa, and Australia during the last 10 years, had no confirmed correlate in the United States until 2002, when R. parkeri was isolated from a patient from the state of Virginia. Several pieces of epidemiologic, laboratory, and clinical evidence are compelling enough to suggest that this infection has occurred in other U.S. patients who reside within the range of the Gulf Coast tick. Just as important are new data indicating relatively high infection rates of A. maculatum ticks with R. parkeri, documenting the occurrence of R. parkeri in Amblyomma triste ticks from Uruguay, and providing evidence that other Amblyomma species might serve as efficient vectors of R. parkeri. The recognition of R. parkeri as a cause of disease in humans will hopefully encourage a closer examination for specific etiologies of tick-borne spotted fever rickettsioses in the United States and other countries of the Western Hemisphere.

  17. Serological prevalence study of exposure of cats and dogs in Launceston, Tasmania, Australia to spotted fever group rickettsiae.

    PubMed

    Izzard, L; Cox, E; Stenos, J; Waterston, M; Fenwick, S; Graves, S

    2010-01-01

    A sero-epidemiological study of cats and dogs in the Launceston area of Tasmania, Australia was undertaken to determine the prevalence of antibodies to spotted fever group (SFG) rickettsiae. Results showed that 59% of cats and 57% of dogs were positive for antibodies, but there was no correlation between the animal's health and seropositivity at the time of testing, suggesting that rickettsial exposure is unrelated to ill-health in these two species of domestic animals.

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

    PubMed

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

    2016-12-28

    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.

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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