| [rickettsioses]. | species of the genus rickettsia are small, obligate intracelular, gramnegative bacteria, many of which are considered nowadays a paradigm of emergent pathogens. with the exception of r. prowazekii, they are maintained in the natural environment through a cycle involving different hosts (mainly mammals), and arthropod vectors (in general ticks, and fleas); humans are affected only by incidental transmission due to arthropod bites. the common pathogenesis of these diseases lie on the predominantly ... | 2005 | 15757589 |
| changes in the adherens junctions of human endothelial cells infected with spotted fever group rickettsiae. | rickettsiae of the spotted fever group are obligately intracellular bacteria that primarily infect the vascular endothelium, invade adjacent cells propelled by actin polymerization, and cause severe systemic diseases. endothelial dysfunction and vascular leakage develop as a consequence; this effect is the pathophysiological mechanism that explains most clinical manifestations. here we report that rickettsial infection of cultured primary human endothelial cells is associated with the formation ... | 2005 | 15778845 |
| analysis of fluorescent protein expression in transformants of rickettsia monacensis, an obligate intracellular tick symbiont. | we developed and applied transposon-based transformation vectors for molecular manipulation and analysis of spotted fever group rickettsiae, which are obligate intracellular bacteria that infect ticks and, in some cases, mammals. using the epicentre ez::tn transposon system, we designed transposons for simultaneous expression of a reporter gene and a chloramphenicol acetyltransferase (cat) resistance marker. transposomes (transposon-transposase complexes) were electroporated into rickettsia mona ... | 2005 | 15812043 |
| [clinical and epidemiological study of spotted fever group rickettsiosis in albacete, spain]. | the aim of this study was to describe the clinical and epidemiological features of spotted fever group rickettsiosis acquired in the province of albacete, spain. | 2005 | 15826542 |
| human spotted fever rickettsial infections. | serum specimens from patients at 4 sites in peru were tested for evidence of spotted fever group rickettsial infection. results showed that 30 (18%) of 170 patients had spotted fever group rickettsial infections, which likely caused their illnesses. these findings document laboratory-confirmed spotted fever from diverse areas of peru. | 2005 | 15829206 |
| [study on the coinfection of three tick-borne infectious diseases in china using polymerase chain reaction method]. | to study the existence of ehrluichiosis, lyme disease and tick-borne spotted fever coinfection in some areas in china. | 2005 | 15921584 |
| evaluation of pcr-based assay for diagnosis of spotted fever group rickettsiosis in human serum samples. | a nested pcr assay was developed for the detection of spotted fever group (sfg) rickettsiae in serum samples. the assay was based on specific primers derived from the rickettsial outer membrane protein b gene (rompb) of rickettsia conorii. an sfg rickettsia-specific signal is obtained from r. akari, r. japonica, r. sibirica, and r. conorii. other bacterial species tested did not generate any signal, attesting to the specificity of the assay. as few as seven copies of the rompb gene of r. conorii ... | 2005 | 15939751 |
| emerging tick-borne infections: rediscovered and better characterized, or truly 'new' ? | the emergence of lyme borreliosis as a public health burden within the last two decades has stimulated renewed interest in tick-borne infections. this attention towards ticks, coupled with advances in detection technologies, has promoted the recognition of diverse emergent or potentially emerging infections, such as monocytic and granulocytic ehrlichiosis, local variants of spotted fever group rickettsioses, wa-1 babesiosis, or a lyme disease mimic (masters' disease). the distribution of pathoge ... | 2004 | 15940821 |
| detection of rickettsia, borrelia, and bartonella in carios kelleyi (acari: argasidae). | carios kelleyi (colley & kohls 1941), a tick associated with bats and bat habitats, has been reported to feed on humans, but there is little published data regarding the presence of vector-borne pathogens in these ticks. c. kelleyi nymphs and adults were collected from residential and community buildings in jackson county, iowa, and tested by polymerase chain reaction for rickettsia, borrelia, bartonella, coxiella, and anaplasma. rickettsia dna was detected in 28 of 31 live ticks. sequences of t ... | 2005 | 15962801 |
| rapid and simple identification of orientia tsutsugamushi from other group rickettsiae by duplex pcr assay using groel gene. | in this study, two new duplex pcr methods based on the groel gene were developed and investigated for the diagnosis of rickettsiae. the first duplex pcr assay amplified the 229-bp and the 366-bp dnas of 6 strains including typhus group (tg) and spotted fever group (sfg) rickettsiae, and 5 scrub typhus group (stg) rickettsiae, respectively. the second duplex pcr assay amplified the 397-bp and the 213-bp dnas of 6 rickettsia strains and 5 stg strains. these duplex pcr methods could simultaneously ... | 2005 | 15965302 |
| prediction of resistance to erythromycin in the genus rickettsia by mutations in l22 ribosomal protein. | typhus group (tg) rickettsiae are naturally susceptible to erythromycin whereas spotted fever group (sfg) rickettsioses are not. the aim of this study was to compare in silico genetic determinants known to be associated with resistance to macrolide compounds. | 2005 | 15996971 |
| simultaneous detection of "rickettsia mongolotimonae" in a patient and in a tick in greece. | rickettsia conorii, a spotted fever group rickettsia which is transmitted by rhipicephalus sp. complex ticks, was considered until now the only pathogenic rickettsia prevalent in greece. here, we report the presence of "rickettsia mongolotimonae" (proposed name) detected simultaneously in a patient and in a hyalomma anatolicum excavatum tick, sampled on the patient. | 2005 | 16000506 |
| rickettsial metk-encoded methionine adenosyltransferase expression in an escherichia coli metk deletion strain. | the obligate intracellular bacterium rickettsia prowazekii has recently been shown to transport the essential metabolite s-adenosylmethionine (sam). the existence of such a transporter would suggest that the metk gene, coding for the enzyme that synthesizes sam, is unnecessary for rickettsial growth. genome sequencing has revealed that this is the case for the metk genes of the spotted fever group and the madrid e strain of r. prowazekii, which contain recognizable inactivating mutations. howeve ... | 2005 | 16077118 |
| detection of brazilian spotted fever infection by polymerase chain reaction in a patient from the state of são paulo. | brazilian spotted fever (bsf) cases have been increasing in the state of são paulo but no genomic information about local rickettsia isolated from humans has been well documented. we recovered spotted-fever group rickettsiae from a sample of patient blood cultured in vero cells using the shell vial technique. rickettsial dna fragments (glta, ompa, and, ompb genes) were detected, and analysis of the ompb gene base sequences showed identity with the rickettsia rickettsii ompb sequence available in ... | 2005 | 16113868 |
| expression and secretion of chemotactic cytokines il-8 and mcp-1 by human endothelial cells after rickettsia rickettsii infection: regulation by nuclear transcription factor nf-kappab. | infection of endothelial cells (ec) with rickettsia rickettsii results in rocky mountain spotted fever, an acute illness characterized by systemic inflammation. interleukin-8 (il-8) and monocyte chemoattractant protein-1 (mcp-1) are important chemokines for activating neutrophils and monocytes, respectively, and recruiting these circulating immune cells to the sites of inflammation. in this study, we have measured the expression and secretion of these chemokines during r. rickettsii infection of ... | 2005 | 16128401 |
| a novel and naturally occurring transposon, isrpe1 in the rickettsia peacockii genome disrupting the ricka gene involved in actin-based motility. | while examining the molecular basis for the lack of actin-based motility for the non-pathogenic spotted fever group (sfg) r. peacockii, we identified a novel insertion sequence (is) element, isrpe1, disrupting the coding sequence of ricka, demonstrated to induce actin-tail polymerization for the sfg rickettsiae. this rickettsial is element appears to be active in that complete terminal inverted repeat and recombinase/transposase open reading frame sequences are present and the transposase is tra ... | 2005 | 16164550 |
| not only 'flinders island' spotted fever. | to demonstrate that flinders island spotted fever (fisf), a spotted fever group rickettsial infection caused by rickettsia honei, is found not only on flinders island (bass strait), tasmania, but elsewhere in south-east australia. | 2005 | 16175900 |
| transcription of the rickettsia felis ompa gene in naturally infected fleas. | rickettsia felis is maintained transovarially in ctenocephalides felis fleas in a widespread geographic distribution and is transmitted to humans and animals, including opossums. this rickettsia is phylogenetically a member of the spotted fever group, most closely related to rickettsia akari and r. australis. an unusual feature of this rickettsia is that the gene for the outer membrane protein a (ompa) is interrupted by stop codons. to determine if this putatively dying gene is expressed, mrna w ... | 2005 | 16222005 |
| factors influencing in vitro infectivity and growth of rickettsia peacockii (rickettsiales: rickettsiaceae), an endosymbiont of the rocky mountain wood tick, dermacentor andersoni (acari, ixodidae). | rickettsia peacockii, a spotted fever group rickettsia, is a transovarially transmitted endosymbiont of rocky mountain wood ticks, dermacentor andersoni. this rickettsia, formerly known as the east side agent and restricted to female ticks, was detected in a chronically infected embryonic cell line, dae100, from d. andersoni. we examined infectivity, ability to induce cytopathic effect (cpe) and host cell specificity of r. peacockii using cultured arthropod and mammalian cells. aposymbiotic dae1 ... | 2005 | 16288906 |
| presence of rickettsia conorii subsp. israelensis, the causative agent of israeli spotted fever, in sicily, italy, ascertained in a retrospective study. | a retrospective analysis by molecular-sequence-based techniques was performed to correctly identify the etiological agent of 24 mediterranean spotted fever cases occurring in western sicily, italy, from 1987 to 2001. restriction analysis of a 632-bp pcr-amplified portion of the ompa gene allowed presumptive identification of five clinical isolates as belonging to rickettsia conorii subsp. israelensis, the etiological agent of israeli spotted fever (isf). the remaining 19 rickettsial isolates wer ... | 2005 | 16333093 |
| a highly sensitive and specific real-time pcr assay for the detection of spotted fever and typhus group rickettsiae. | a highly specific real-time polymerase chain reaction (pcr) assay was developed to detect spotted fever and typhus group rickettsiae using the citrate synthase gene as the target. the assay amplified rickettsial members of the spotted fever and typhus group including rickettsia akari, r. australis, r. conorii, r. honei, "r. marmionii," r. sibirica, r. rickettsii, r. typhi, and r. prowazekii. the ancestral group rickettsia, r. bellii, did not produce a positive reaction, nor did other members of ... | 2005 | 16354816 |
| laboratory-confirmed mediterranean spotted fever in a japanese traveler to kenya. | a japanese traveler returning from kenya became ill, presenting with fever and a prominent, generalized rash without an eschar. results of the immunofluorescence antibody assay of the patient's sera performed in japan were compatible with illness due to a spotted fever group (sfg) rickettsia, and a presumptive diagnosis of african sfg rickettsiosis, probably either mediterranean spotted fever (msf) or african tick-bite fever (atbf), was rendered. to further define the disease diagnosis, sera wer ... | 2005 | 16354817 |
| evidence of a spotted fever-like rickettsia and a potential new vector from northeastern australia. | a spotted fever-like rickettsia was identified in a hemaphysalis tick by polymerase chain reaction (pcr) amplification and sequencing of the 16s rdna, ompa, and ompb genes. a comparison of these nucleotide sequences with those of other spotted fever group (sfg) rickettsiae revealed that the hemaphysalis tick rickettsia ia was distinct from other previously reported strains. phylogenetic analysis based on both ompa and ompb also indicates that the strain's closest relatives are the agents of thai ... | 2005 | 16363177 |
| rickettsial infections around the world, part 1: pathophysiology and the spotted fever group. | the rickettsial diseases are an important group of infectious agents that have dermatological manifestations. these diseases are important to consider in endemic areas, but in certain suspicious cases, possible acts of bioterrorism should warrant prompt notification of the appropriate authorities. | 2005 | 16392014 |
| [rickettsia helvetica: an emerging tick-borne pathogen in hungary and europe]. | rickettsia helvetica belonging to spotted fever group rickettsiae was recently detected by polymerase chain reaction followed by sequencing in european sheep ticks (ixodes ricinus) from hungary. current knowledge on these rickettsiae and the clinical and diagnostic aspects of r. helvetica infection is summarized. in acute cases, r. helvetica is generally responsible for flu-like symptoms. nevertheless, recent data indicate that in chronic cases, these rickettsiae can be responsible for perimyoca ... | 2005 | 16440500 |
| antibodies to rickettsia rickettsii, rickettsia typhi, coxiella burnetii, bartonella henselae, bartonella quintana, and ehrlichia chaffeensis among healthy population in minas gerais, brazil. | 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 wa ... | 2006 | 16444416 |
| survey of rickettsial antibodies at two local sites and review of rickettsiosis in papua new guinea. | the status of rickettsial infection in papua new guinea (png) is unknown although several reports of typhus-like illnesses infecting predominantly white settlers and the allied troops during world war 2 were published between 1930 and 1945. we performed a serological survey for evidence of rickettsial infection by measuring rickettsia-specific antibody levels in the blood of 191 non-randomly selected papua new guineans living in port moresby (n=93) and in the highland villages of samberigi (n=98 ... | 2003 | 16450784 |
| broad-range pcr-ttge for the first-line detection of bacterial pathogen dna in ticks. | ticks are known or suspected vectors for a wide range of bacterial pathogens. one of the first steps for tick-borne risk assessment is the detection of these pathogens in their vectors. in the present study, a broad-range pcr amplification of the eubacterial gene encoding the 16s rrna gene combined with temporal temperature gradient gel electrophoresis (ttge) was evaluated as a method allowing the one-step detection of bacterial pathogen dna in ticks. firstly, dna extracts from bacteria known to ... | 2006 | 16472523 |
| characterisation of rickettsial diseases in a hospital-based population in malta. | the aim of the study was to characterise the causative agents of rickettsial disease in malta. a secondary objective was to study the epidemiology of cases of rickettsial disease. | 2006 | 16473410 |
| rickettsial infections. | rickettsiae are obligate intracellular alpha-proteobacteria that primarily target the microvascular endothelium. in the last two decades, new rickettsial pathogens have been associated with human illness around the world. clinically, the common denominator in all rickettsioses is the development of increased microvascular permeability, leading to cerebral and non-cardiogenic pulmonary edema. with the development of powerful research tools, advances in the understanding of rickettsial pathogenesi ... | 2005 | 16481513 |
| similarities and differences in host cell signaling following infection with different rickettsia species. | signaling interactions between vascular endothelium and invading rickettsiae provide a unique way of coordinating appropriate physiologic responses, which are important determinants of the ensuing pathogenesis mechanisms such as host defense and inflammation. two major subgroups of pathogenic rickettsia species, namely the typhus group (tg) and the spotted fever group (sfg), exhibit marked differences in their intracytoplasmic behavior. using in vitro infection of cultured human endothelial cell ... | 2005 | 16481515 |
| potential roles for regulatory oxygenases in rickettsial pathogenesis. | clinical and experimental evidence suggests an important role for oxidative stress and associated cellular defense mechanisms in the pathogenesis of vasculopathic rickettsioses. our laboratory has reported that r. rickettsii infection of endothelial cells in vitro induces the expression of ho-1, the inducible isoform of the antioxidant defense enzyme heme oxygenase. ho-1 plays a critical role in maintaining the integrity of the vasculature and controls the functioning of the cyclooxygenase (cox) ... | 2005 | 16481516 |
| growth of typhus group and spotted fever group rickettsiae in insect cells. | to analyze the host dependency of rickettsial growth, nias-aeal-2 insect cells (aeal2) derived from mosquito were first used in this study. it was demonstrated that typhus group rickettsiae (tgr) grew well in aeal2 cells, but spotted fever group rickettsiae (sfgr) failed. to elucidate the inhibitory process of the growth of sfgr in aeal2 cells, the adherence and invasion were first analyzed. sfgr possessed abilities to adhere to and invade aeal2 cells as well as tgr in contrast to their inabilit ... | 2005 | 16481517 |
| genome comparison analysis of molecular mechanisms of resistance to antibiotics in the rickettsia genus. | in this study we describe molecular mechanisms of resistance to several classes of antibiotics within drug targets by in silico genome comparisons for bacteria of the genus rickettsia. apart from the mutations in the rpob gene in naturally rifampin-resistant rickettsia species previously reported by our team, we found that typhus group (tg) rickettsiae had a triple amino acid difference in the highly conserved region of the l22 ribosomal protein as compared to the spotted fever group rickettsiae ... | 2005 | 16481518 |
| analysis of immunoprotectivity of the recombinant ompa of rickettsia heilongjiangensis. | a truncated gene ompa was amplified from rickettsia heilongjiangensis isolated in china and a 56-kda truncated ompa protein was expressed in e. coli cells transformed with the ompa-recombined expression plasmid. high levels of serum antibodies to r. heilongjiangensis and proliferation of the splenic cells were found in mice immunized with the truncated ompa. after challenge with r. heilongjiangensis or r. rickettsii, fever and pathological damages of the guinea pigs immunized with the truncated ... | 2005 | 16481525 |
| rickettsia parkeri as a paradigm for multiple causes of tick-borne spotted fever in the western hemisphere. | 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 res ... | 2005 | 16481534 |
| phylogenetic analysis of a novel molecular isolate of spotted fever group rickettsiae from northern peru: candidatus rickettsia andeanae. | phylogenetic analysis of five rickettsial genes (17-kda gene, glta, ompb, ompa, and sca4) from two molecular isolates of candidatus rickettsia andeanae from two ticks (amblyomma maculatum and ixodes boliviensis) collected from two domestic horses living in two separate locations in northern peru (coletas and naranjo) was conducted to more clearly characterize this recently reported novel spotted fever group (sfg) rickettsia. following nested polymerase chain reaction (pcr) amplification of the 1 ... | 2005 | 16481537 |
| novel spotted fever group rickettsiae (sfgr) infecting amblyomma americanum ticks in ohio, usa. | | 2005 | 16481541 |
| rickettsia africae in the west indies. | rickettsia africae is the agent of african tick-bite fever, a mild but common disease of local persons and tourists in africa. the major vector of this spotted fever group rickettsia is most likely amblyomma variegatum, the tropical bont tick, which has become widely distributed through the west indies in the last 30 years. this report reviews all available information on r. africae in the west indies. | 2006 | 16494746 |
| rickettsial infections and fever, vientiane, laos. | rickettsial diseases have not been described previously from laos, but in a prospective study, acute rickettsial infection was identified as the cause of fever in 115 (27%) of 427 adults with negative blood cultures admitted to mahosot hospital in vientiane, laos. the organisms identified by serologic analysis were orientia tsutsugamushi (14.8%), rickettsia typhi (9.6%), and spotted fever group rickettsia (2.6% [8 r. helvetica, 1 r. felis, 1 r. conorii subsp. indica, and 1 rickettsia "at1"]). pa ... | 2006 | 16494751 |
| the major outer membrane protein rompb of spotted fever group rickettsiae functions in the rickettsial adherence to and invasion of vero cells. | the role of one of the major outer membrane proteins, rompb, of spotted fever group rickettsiae was examined. antibodies generated against native rompb inhibited plaque formation by rickettsia japonica in vero cells when applied at the time of inoculation of the rickettsiae. however, antibodies to heat-denatured rompb did not. moreover, the soluble recombinant rompb also inhibited plaque formation to some extent. thus it seems that rompb functions at least in the adherence of rickettsiae to host ... | 2006 | 16500128 |
| [rickettsiae detection in amblyomma ticks (acari: ixodidae) collected in the urban area of campinas city, sp]. | the city of campinas is located in an endemic area for brazilian spotted fever in são paulo state, where several cases have recently occurred. capybaras have been associated with the cycle of this disease, for they present positive serology and serve as host for ticks of the genus amblyomma, the main vectors of brazilian spotted fever. ticks were collected both from capybaras and from the vegetation in the city park lago do café, located in the urban area of campinas city, sp, a site associated ... | 2006 | 16501770 |
| detection of spotted fever group (sfg) rickettsiae in dermacentor reticulatus (acari: ixodidae) in poland. | dermacentor reticulatus ticks from poland were investigated by molecular methods for the presence of rickettsiae. during 2003/2004, a total of 285 adult ticks was assayed using primers rpcs.877 and rpcs.1258 derived from the citrate synthase (glta) gene, and 116 samples (40.7%) were positive for rickettsial dna. ten out of these positive samples were further assayed using slo1f and slo1r primers derived form the rompa-encoding gene to confirm that detected rickettsiae belong to the spotted fever ... | 2006 | 16524778 |
| molecular identification of a collection of spotted fever group rickettsiae obtained from patients and ticks from russia. | thirty-one rickettsial isolates from ticks or patients in north asian tick typhus (natt) foci from the ural region to the russian far east were obtained at the omsk research institute of natural foci infections between 1954 and 2001. using citrate synthase (glta) and outermenbrane protein a (ompa) gene sequencing, we identified these isolates as rickettsia sibirica sensu stricto (25 isolates), r. sibirica strain bj-90 (2 isolates), r. slovaca (1 isolate), and r. heilongjiangensis (3 isolates). w ... | 2006 | 16525104 |
| borrelia lusitaniae and spotted fever group rickettsiae in ixodes ricinus (acari: ixodidae) in tuscany, central italy. | prevalence of infection by borrelia burgdorferi s.l. and spotted fever group (sfg) rickettsiae was estimated in host-seeking ticks in an area in tuscany, central italy, where lyme borreliosis was reported in a forestry worker. b. burgdorferi s.l. was identified by polymerase chain reaction in 16.7% (95% ci = 10.3, 24.8) of ixodes ricinus (l.) nymphs and 39.6% (95% ci = 26.5, 54.0) of adults. borrelia lusitaniae accounted for 82.9% of positive samples, followed by borrelia garinii (9.8%), borreli ... | 2006 | 16619594 |
| rickettsiae of the spotted-fever group in ixodid ticks from hungary: identification of a new genotype ('candidatus rickettsia kotlanii'). | three common european 'anthrophilic' ticks, ixodes ricinus, haemaphysalis concinna and dermacentor reticulatus, were collected in hungary and tested, in assays based on nested pcr, for rickettsiae of the spotted-fever group. low percentages of i. ricinus (2.7%) and h. concinna (1.0%) and a high percentage of d. reticulatus (26.8%) were found to be infected. the rickettsiae in the ticks were then identified, by sequencing of the genes coding for 16s ribosomal rna (16s rdna), citrate synthase (glt ... | 2006 | 16630380 |
| tropical rickettsioses. | in recent years, a bewildering array of emerging rickettsial pathogens have been described throughout the world, including in the tropics. here we present an updated overview of scrub typhus, murine typhus, and epidemic typhus. we also present an update on the emerging spotted fever group rickettsioses described in the tropics through 2005, focusing on epidemiologic and clinical data and management. | 2006 | 16714200 |
| the seroprevalence of human infection with rickettsia slovaca, in an area of northern spain. | an epidemiological survey was undertaken to explore human exposure to rickettsia slovaca in two provinces of northern spain. when ifat were used to test 200 members of the general population for antibodies to rickettsiae of the spotted-fever group, six (3.3%) were found positive, presumably, since dermacentor is one of the most common genera of human-biting tick in the study area, for antibodies to r. slovaca. thirty-one (16.9%) of an additional 183 subjects who presented shortly after being bit ... | 2006 | 16762114 |
| rickettsia tamurae sp. nov., isolated from amblyomma testudinarium ticks. | rickettsia sp. strain at-1(t) was isolated from amblyomma testudinarium ticks in japan in 1993. comparative analysis of sequences obtained from 16s rrna, glta, ompa, ompb and sca4 gene fragments demonstrated those from at-1(t) to be markedly different from those of other members of the spotted fever group. using mouse serotyping, it was also observed that rickettsia sp. strain at-1(t) was different from other rickettsia species with validly published names. such genotypic and phenotypic characte ... | 2006 | 16825648 |
| japanese spotted fever, south korea. | we describe the first case of japanese spotted fever and the first isolate of spotted fever group rickettsia from a patient in south korea. the isolated rickettsia from the patient was identified as rickettsia japonica by analysis of the nucleotide sequences of 16s rrna, glta, ompa, ompb, and sca4 genes. | 2006 | 16836831 |
| surveillance of egyptian fleas for agents of public health significance: anaplasma, bartonella, coxiella, ehrlichia, rickettsia, and yersinia pestis. | 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 fro ... | 2006 | 16837707 |
| isolation and identification of rickettsia massiliae from rhipicephalus sanguineus ticks collected in arizona. | twenty rhipicephalus sanguineus ticks collected in eastern arizona were tested by pcr assay to establish their infection rate with spotted fever group rickettsiae. with a nested pcr assay which detects a fragment of the rickettsia genus-specific 17-kda antigen gene (htra), five ticks (25%) were found to contain rickettsial dna. one rickettsial isolate was obtained from these ticks by inoculating a suspension of a triturated tick into monolayers of vero e6 monkey kidney cells and xtc-2 clawed toa ... | 2006 | 16885311 |
| rickettsia felis from cat fleas: isolation and culture in a tick-derived cell line. | rickettsia felis, the etiologic agent of spotted fever, is maintained in cat fleas by vertical transmission and resembles other tick-borne spotted fever group rickettsiae. in the present study, we utilized an ixodes scapularis-derived tick cell line, ise6, to achieve isolation and propagation of r. felis. a cytopathic effect of increased vacuolization was commonly observed in r. felis-infected cells, while lysis of host cells was not evident despite large numbers of rickettsiae. electron microsc ... | 2006 | 16885313 |
| increased levels of soluble cd40l in african tick bite fever: possible involvement of tlrs in the pathogenic interaction between rickettsia africae, endothelial cells, and platelets. | the pathophysiological hallmark of spotted fever group rickettsioses comprises infection of endothelial cells with subsequent infiltration of inflammatory cells. based on its ability to promote inflammation and endothelial cell activation, we investigated the role of cd40l in african tick bite fever (atbf), caused by rickettsia africae, using different experimental approaches. several significant findings were revealed. 1) patients with atbf (n = 15) had increased serum levels of soluble cd40 li ... | 2006 | 16888032 |
| infection of human endothelial cells with spotted fever group rickettsiae stimulates cyclooxygenase 2 expression and release of vasoactive prostaglandins. | rickettsiae, a diverse group of obligately intracellular gram-negative bacteria, include etiologic agents of the spotted fever and typhus groups of diseases. rocky mountain spotted fever and boutonneuse fever, due to rickettsia rickettsii and r. conorii, respectively, are characterized by widespread infection of the vascular endothelium, microvascular injury, and vasculitis. cultured human endothelial cells (ec) are highly susceptible to infection and respond by altering the expression of adhesi ... | 2006 | 16926398 |
| [study on the coinfection status of borrelia burgdorferi sensu lato and spotted fever group rickettsia in ticks from hunchun, jilin province]. | to understand the coinfection status of borrelia burgdorferi sensu lato (b.b.s.l) and spotted fever group rickettsia (sfgr) in hunchun of jilin province, china. | 2006 | 16981329 |
| rickettsia as obligate and mycetomic bacteria. | rickettsiae are well known as intracellular pathogens of animals, humans, and plants and facultative and unorganized symbionts of invertebrates. no close relative of mitochondria has yet been associated with nutritional or developmental dependency of its host cell or organism. we have found a mycetomic rickettsia that is a strict obligatory symbiont of the parthenogenetic booklouse liposcelis bostrychophila (psocoptera). these rickettsiae show an evolutionary transition from a solitary to a prim ... | 2006 | 17012243 |
| a spotted fever group rickettsia from an exotic tick species, amblyomma exornatum (acari: ixodidae), in a reptile breeding facility in the united states. | 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 amb ... | 2006 | 17017252 |
| epidemiology of rickettsioses in north africa. | the first description of mediterranean spotted fever (msf) was made by conor and brush in 1910 in tunisia, where, at the same time, nicolle described the role of lice in transmission of epidemic typhus. however, along this century, there have been few and fragmentary reports about ecology and epidemiology of rickettsioses in north africa. this region was always considered, for these diseases, like other mediterranean regions. the most human tick-borne rickettsiosis known to occur in north africa ... | 2006 | 17114678 |
| rickettsioses in sub-saharan africa. | although rickettsioses are among the oldest known vector-borne zoonoses, several species or subspecies of rickettsias have been identified in recent years as emerging pathogens throughout the world including in sub-saharan africa. to date, six tick-borne spotted fever group pathogenic rickettsias are known to occur in sub-saharan africa, including rickettsia conorii conorii, the agent of mediterranean spotted fever; r. conorii caspia, the agent of astrakhan fever; r. africae, the agent of africa ... | 2006 | 17114679 |
| rickettsial diseases in russia. | currently, several rickettsioses are officially being reported in the russian federation. these are epidemic typhus and brill-zinsser disease, both caused by rickettsia prowazekii which has a historic prevalence in russia. nowadays only single sporadic cases of r. prowazekii infection are reported. the last significant outbreak occurred in 1997 in a mental nursing home, where 29 cases were identified. registered morbidity of typhus in russia varies from 0 to 0.01 per thousand for the last decade ... | 2006 | 17114680 |
| rickettsioses in japan and the far east. | three rickettsial diseases are known to exist in japan currently: japanese spotted fever (jsf), tsutsugamushi disease (td; scrub typhus), and q fever. since april 1999, the system for infection control and prevention in japan has changed drastically. jsf, q fever, and td, as emerging infectious diseases, are designated as national notifiable diseases.the geographic distribution of jsf patients is along the coast of central and southwestern japan, whereas td and q fever occur almost all over the ... | 2006 | 17114681 |
| rickettsioses in australia. | australia, an island continent in the southern hemisphere, has a range of rickettsial diseases that include typhus group rickettsiae (rickettsia typhi), spotted fever group rickettsiae (r. australis, r. honei), scrub typhus group rickettsiae (r. tsutsugamushi), and q fever (c. burnetii). our knowledge of australian rickettsiae is expanding with the recognition of an expanded range of r. honei (flinders island spotted fever) to tasmania and southeastern mainland australia (not just on flinders is ... | 2006 | 17114682 |
| far eastern tick-borne rickettsiosis: identification of two new cases and tick vector. | we recently reported the first documented cases of a new rickettsial disease caused by rickettsia heilongjiangensis in the russian far east (far eastern tick-borne rickettsiosis). here we report the amplification of dna of r. heilongjiangensis from both the skin biopsy of an acutely ill patient and the tick removed from him prior to the disease development. the tick has been identified as haemaphysalis spp. the clinical picture was that of a spotted fever group rickettsiosis and a seroconversion ... | 2006 | 17114683 |
| prospective evaluation of rickettsioses in the trakya (european) region of turkey and atypic presentations of rickettsia conorii. | in 2004 between the months of may-november, 11 patients with spotted fever group (sfg) rickettsioses were admitted to the trakya university hospital in edirne, turkey. sfg rickettsioses were diagnosed clinically. before treatment, punch biopsy from skin lesions, especially from the eschar, was performed. serum specimens were tested by ifa using a panel of nine rickettsial antigens, including sfg rickettsiae and r. typhi. western blotting and standard pcr were also performed. the average age of t ... | 2006 | 17114703 |
| serologic study of rickettsioses among acute febrile patients in central tunisia. | although mediterranean spotted or "boutonneuse" fever (msf) has been documented in central tunisia, other spotted fever group rickettsioses (sfgr) and typhus group rickettsioses (tgr) have received little attention in our region. we sought to determine the role of rickettsioses, q fever, ehrlichioses, and bartonelloses among patients with acute fever. the results of this study of 47 persons with acute fever of undetermined origin are reported in this paper. we concluded that sfgr, murine typhus, ... | 2006 | 17114704 |
| detection and identification of a novel spotted fever group rickettsia in western australia. | 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 evolut ... | 2006 | 17114708 |
| prevalence of bacterial agents in ixodes persulcatus ticks from the vologda province of russia. | the prevalence of rickettsiae, ehrlichiae, and the rickettsia-like endosymbiont called montezuma relative to that of borrelia was determined in questing ixodes persulcatus (i. persulcatus) ticks collected in 2002-2003 from vologda province, russia. ehrlichia muris, anaplasma phagocytophilum, montezuma, and new spotted fever group rickettsiae were detected by polymerase chain reaction (pcr) for the first time in this area. the rickettsiae were all candidatus rickettsia tarasevichiae, the furthest ... | 2006 | 17114724 |
| prevalence of spotted fever group rickettsia species detected in ticks in la rioja, spain. | 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. ... | 2006 | 17114730 |
| prevalence of rickettsia slovaca in dermacentor marginatus ticks removed from wild boar (sus scrofa) in northeastern spain. | rickettsia slovaca, the causative agent of tibola, is transmitted by dermacentor ticks. dermacentor marginatus is the most widely species distributed in northeastern spain, and the wild boar constitutes the main host. d. marginatus ticks were collected from hunter-killed wild boar and were tested by pcr/rflp. rickettsial dna-positive ticks were sequenced using the ompa pcr primers. the prevalence of r. slovaca in d. marginatus ticks was 17.7%. other spotted fever group rickettsiae were detected ... | 2006 | 17114731 |
| prevalence data of rickettsia slovaca and other sfg rickettsiae species in dermacentor marginatus in the southeastern iberian peninsula. | in southern spain, dermacentor marginatus ticks can be infected with several genospecies of spotted fever group (sfg) rickettsia. we developed a nested polymerase chain reaction assay by using a species-specific probe targeting the ompa gene to detect and differentiate between the two groups of rickettsiae previously described in d. marginatus. sfg rickettsia has been detected in 85.15% of ticks studied (26.7% of positives have been to r. slovaca, the causative agent of tibola-debonel, and 73.3% ... | 2006 | 17114732 |
| spotted fever group rickettsiae in ticks feeding on humans in northwestern spain: is rickettsia conorii vanishing? | during a 7-year study, we identified and analyzed by pcr 4,049 ticks removed from 3,685 asymptomatic patients in castilla y león (northwestern spain). a total of 320 ticks (belonging to 10 species) were pcr-positive for rickettsiae. comparison of amplicon sequences in databases enabled us to identify eight different spotted fever group (sfg) rickettsiae: rickettsia slovaca, rickettsia sp. irs3/irs4, r. massiliae/bar29, r. aeschlimannii, rickettsia sp. rpa4/dns14, r. helvetica, rickettsia sp. dms ... | 2006 | 17114733 |
| population survey of egyptian arthropods for rickettsial agents. | between june 2002 and july 2003, 987 fleas, representing four species, and 1019 ticks, representing one argasid and eight ixodid species, were collected from egyptian animals. these arthropods were tested for rickettsial agents using polymerase chain reaction. dnas from anaplasma and ehrlichia spp. were detected in 13 ticks. previously undescribed bartonella spp. were detected in 21 fleas. coxiella burnetii was detected in two fleas and 20 ticks. rickettsia typhi was detected in 27 fleas from 10 ... | 2006 | 17114742 |
| first molecular detection of r. conorii, r. aeschlimannii, and r. massiliae in ticks from algeria. | ticks collected in northern algeria between may 2001 and november 2003 were tested by pcr for the presence of rickettsia spp. dna using primer amplifying glta and ompa genes. three different spotted fever group rickettsias were amplified from these ticks: r. conorii subsp. p. conorii strain malish in rhipicephalus sanguineus, r. aeschlimannii in hyalomma marginatum, and r. massiliae in rhipicephalus turanicus. our results confirm the presence of r. conorii in ticks in algeria and provide the fir ... | 2006 | 17114743 |
| ornithodoros moubata, a soft tick vector for rickettsia in east africa? | omithodoros moubata complex (argasidae) ticks collected from human dwellings in central tanzania were found to carry a novel rickettsial species that clustered among the spotted fever group. although no evidence of human infection was evident, these ticks feed primarily on man, thus providing opportunity for zoonotic infection. | 2006 | 17114744 |
| ticks, tick-borne rickettsiae, and coxiella burnetii in the greek island of cephalonia. | domestic animals are the hosts of several tick species and the reservoirs of some tick-borne pathogens; hence, they play an important role in the circulation of these arthropods and their pathogens in nature. they may act as vectors, but, also, as reservoirs of spotted fever group (sfg) rickettsiae, which are the causative agents of sfg rickettsioses. q fever is a worldwide zoonosis caused by coxiella burnetii (c. burnetii), which can be isolated from ticks. a total of 1,848 ticks (954 female, 8 ... | 2006 | 17114747 |
| the occurrence of spotted fever group (sfg) rickettsiae in ixodes ricinus ticks (acari: ixodidae) in northern poland. | ixodes ricinus, the most commonly observed tick species in poland, is known vector of microorganisms pathogenic for humans as tbe virus, borrelia burgdorferi s.1., anaplasma phagocytophilum and babesia sp. in this country. our study aimed to find out whether this tick can also transmit also rickettsiae of the spotted fever group (sfg). dna extracts from 560 ticks (28 females, 34 males, and 488 nymphs) collected in different wooded areas in northern poland were examined by pcr for the detection o ... | 2006 | 17114767 |
| spotted fever group rickettsial infection in dogs from eastern arizona: how long has it been there? | a serosurvey of free-roaming dogs for antibodies to spotted fever group rickettsiae was conducted using archival samples that had been collected in the white mountain region of eastern arizona during a plague study in 1996. immunoglobulin g antibodies to rickettsia rickettsii (5.1%) and to r. rhipicephali (3.6%) were demonstrated, and no cross-reactive samples were identified. this study indicates that r. rickettsii was likely present in the dog populations in this area prior to the recognition ... | 2006 | 17114769 |
| evaluation of igg antibody response against rickettsia conorii and rickettsia slovaca in patients with debonel/tibola. | the aim of the study was to determine the igg antibody response to spotted fever group rickettsia (sfgr) r. conorii and r. slovaca, and its specificity and sensitivity in patients with debonel/tibola. a prospective study of 31 patients with debonel was carried out from january 2001 to may 2004. the sfgr serology testing (igg ifa) for the diagnosis of debonel/tibola showed 61% sensitivity and 100% specificity. the r. slovaca antigen allowed the diagnoses in 18 of the 31 patients (58%), and 17 pat ... | 2006 | 17114780 |
| monitoring of humans and animals for the presence of various rickettsiae and coxiella burnetii by serological methods. | serological examination of humans in slovakia suspected of having rickettsial infections revealed the presence of antibodies to spotted fever group rickettsiae (r. conorii, r. slovaca, and r. typhi). of interest is the finding of serological positivity to the newly recognized "irs" agent. antibodies to these rickettsiae and to c. burnetii were demonstrated also in domestic and hunting dogs and pet animals. these results confirm the occurrence and possible circulation of these rickettsiae and c. ... | 2006 | 17114784 |
| potentially pathogenic spotted fever group rickettsiae present in western australia. | | 2006 | 17121510 |
| infection of ixodes scapularis ticks with rickettsia monacensis expressing green fluorescent protein: a model system. | ticks (acari: ixodidae) are ubiquitous hosts of rickettsiae (rickettsiaceae: rickettsia), obligate intracellular bacteria that occur as a continuum from nonpathogenic arthropod endosymbionts to virulent pathogens of both arthropod vectors and vertebrates. visualization of rickettsiae in hosts has traditionally been limited to techniques utilizing fixed tissues. we report epifluorescence microscopy observations of unfixed tick tissues infected with a spotted fever group endosymbiont, rickettsia m ... | 2007 | 17125789 |
| prevalence of ehrlichia, borrelia, and rickettsial agents in amblyomma americanum (acari: ixodidae) collected from nine states. | ambyomma americanum (l.) (acari: ixodidae) is an aggressive tick that feeds on humans during all postembryonic life stages. in many regions of the united states, it is the tick most commonly found attached to humans. public health interest has grown recently, due to the recognition of new human pathogens transmitted by a. americanum and the expanding distribution of the tick. a. americanum is a vector of several bacteria pathogenic to humans. ehrlichia chaffeensis and ehrlichia ewingii cause mod ... | 2006 | 17162962 |
| rickettsiae phylogeny: a multigenic approach. | the development of molecular taxonomic methods has provided a large amount of data in the reorganization of rickettsiae taxonomy. nevertheless, phylogenetic relationships among some groups and species delimitation remain unclear. to clarify rickettsial phylogeny, a multigenic approach was used for the first time for the genus rickettsia, based on simultaneous analyses of eight loci: atpa, reca, virb4, dnaa, dnak, rrl-rrf internal transcribed spacer, ompa and glta. concatenation of different nucl ... | 2007 | 17185544 |
| serologic survey of eptesicus fuscus from georgia, u.s.a. for rickettsia and borrelia and laboratory transmission of a rickettsia by bat ticks. | bats and their ectoparasites are associated with bacterial agents of unknown pathogenicity. we tested sera from 56 eptesicus fuscus from georgia against borrelia hermsii, orientia tsutsugamushi, rickettsia conorii, and rickettsia rickettsii. we detected antibodies reactive against a relapsing fever borrelia and spotted fever group rickettsia in 3/56 and 1/56 bats, respectively. we attempted to culture bartonella from the blood of these bats but were unsuccessful. in addition, we fed bat ticks, c ... | 2006 | 17249357 |
| new tick defensin isoform and antimicrobial gene expression in response to rickettsia montanensis challenge. | recent studies aimed at elucidating the rickettsia-tick interaction have discovered that the spotted fever group rickettsia rickettsia montanensis, a relative of r. rickettsii, the etiologic agent of rocky mountain spotted fever, induces differential gene expression patterns in the ovaries of the hard tick dermacentor variabilis. here we describe a new defensin isoform, defensin-2, and the expression patterns of genes for three antimicrobials, defensin-1 (vsna1), defensin-2, and lysozyme, in the ... | 2007 | 17261604 |
| spotted fever rickettsioses in southern and eastern europe. | mediterranean spotted fever due to rickettsia conorii conorii was thought, for many years, to be the only tick-borne rickettsial disease prevalent in southern and eastern europe. however, in recent years, six more species or subspecies within the spotted fever group of the genus rickettsia have been described as emerging pathogens in this part of the world. tick-borne agents include rickettsia conorii israelensis, rickettsia conorii caspia, rickettsia aeschlimannii, rickettsia slovaca, rickettsi ... | 2007 | 17266709 |
| detection of rickettsia rickettsii and bartonella henselae in rhipicephalus sanguineus ticks from california. | 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. rick ... | 2007 | 17294935 |
| a tick-borne rickettsia of the spotted-fever group, similar to rickettsia amblyommii, in french guyana. | | 2007 | 17316505 |
| plasmids and rickettsial evolution: insight from rickettsia felis. | 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 enc ... | 2007 | 17342200 |
| differential interaction of dendritic cells with rickettsia conorii: impact on host susceptibility to murine spotted fever rickettsiosis. | spotted fever group rickettsioses are emerging and reemerging infectious diseases, some of which are life-threatening. in order to understand how dendritic cells (dcs) contribute to the host resistance or susceptibility to rickettsial diseases, we first characterized the in vitro interaction of rickettsiae with bone marrow-derived dcs (bmdcs) from resistant c57bl/6 (b6) and susceptible c3h/hen (c3h) mice. in contrast to the exclusively cytosolic localization within endothelial cells, rickettsiae ... | 2007 | 17403875 |
| histopathologic, immunohistochemical, and polymerase chain reaction assays in the study of cases with fatal sporadic myocarditis. | paraffin tissue blocks from 27 cases with sporadic myocarditis were collected during a 12-year period at a single medical examiner's office. blocks were studied by using histopathology; immunohistochemistry for viruses (adenovirus, enterovirus, influenza a and b, and human herpes types 4 and 5), bacteria (neisseria meningitidis, ehrlichia sp, spotted fever group rickettsia) and parasites (toxoplasma gondii and trypanosoma cruzi); and polymerase chain reaction (pcr)/rt-pcr for adenovirus and ente ... | 2007 | 17602724 |
| rickettsia conorii in humans and dogs: a seroepidemiologic survey of two rural villages in israel. | the prevalence of igg-antibodies reactive with an israeli strain of rickettsia conorii (israeli strain 487), the agent of israeli spotted fever, was examined in humans and dogs from two rural villages in israel where the disease has been reported in humans. sixty-nine of 85 (81%) canine sera and 14 of 136 (10%) of human sera had anti-r. conorii antibodies. no direct association could be made between seropositivity of people and ownership of a seropositive dog. this study indicates that exposure ... | 2007 | 17620644 |
| detection of rickettsia africae in rhipicephalus (boophilus) decoloratus ticks from the republic of botswana, south africa. | a total of 53 engorged adult ticks belonging to the species rhipicephalus (boophilus) decoloratus (n = 9), rhipicephalus evertsi evertsi (n = 27), rhipicephalus appendiculatus (n = 9), amblyomma hebraeum (n = 5), and hyalomma marginatum turanicum (n = 3), were removed from oryx in botswana (south africa). they were tested for the presence of spotted fever group (sfg) rickettsia and anaplasma phagocytophilum using polymerase chain reaction (pcr). seventy-seven percent of r. decoloratus as well as ... | 2007 | 17690416 |
| prevalence of antibodies against spotted fever group rickettsiae in a rural area of colombia. | we recently rediscovered rocky mountain spotted fever in villeta, colombia, near the same locality (tobia) where it was first recognized in 1937. to have a better idea of the magnitude of this problem, sera from 392 randomly recruited healthy adults from villeta were analyzed by indirect immunofluorescent antibody assay to detect igg against rickettsia rickettsii as antigen. the seropositivity rate for spotted fever group rickettsiae was 40.3%. we did not find any association between the presenc ... | 2007 | 17690417 |
| tick-borne zoonotic bacteria in wild and domestic small mammals in northern spain. | the prevalence and diversity of tick-borne zoonotic bacteria (borrelia spp., anaplasma phagocytophilum, coxiella burnetii, and spotted fever group rickettsiae) infecting 253 small mammals captured in the basque country (spain) were assessed using pcr and reverse line blot hybridization. trapping sites were selected around sheep farms (study 1, 2000 to 2002) and recreational parks (study 2, 2003 to 2005). the majority of the studied mammals (162) were wood mice (apodemus sylvaticus), but six othe ... | 2007 | 17693556 |
| propagation of arthropod-borne rickettsia spp. in two mosquito cell lines. | rickettsiae are obligate intracellular alphaproteobacteria that include pathogenic species in the spotted fever, typhus, and transitional groups. the development of a standardized cell line in which diverse rickettsiae can be grown and compared would be highly advantageous to investigate the differences among and between pathogenic and nonpathogenic species of rickettsiae. although several rickettsial species have been grown in tick cells, tick cells are more difficult to maintain and they grow ... | 2007 | 17766452 |
| detection of a novel spotted fever group rickettsia in amblyomma parvum ticks (acari: ixodidae) from argentina. | the present study evaluated the rickettsial infection in amblyomma parvum ticks collected in northwestern córdoba province, argentina. each tick was subjected to dna extraction and tested by polymerase chain reaction (pcr) targeting fragments of the rickettsial genes glta and ompb. nine (69.2%) out of 13 adult ticks yielded expected pcr products for the two rickettsial genes. products from the ompb pcr were sequenced, generating dna sequences 100% identical for the nine pcr-positive ticks. three ... | 2007 | 17768597 |
| rickettsial infections and their clinical presentations in the western province of sri lanka: a hospital-based study. | rickettsial infections are re-emerging. a study of the geographical distribution of rickettsial infections, their clinical manifestations, and their complications would facilitate early diagnosis. | 2008 | 17900956 |
| lateral gene transfer between obligate intracellular bacteria: evidence from the rickettsia massiliae genome. | rickettsia massiliae is a tick-borne obligate intracellular alpha-proteobacteria causing spotted fever in humans. here, we present the sequence of its genome, comprising a 1.3-mb circular chromosome and a 15.3-kb plasmid. the chromosome exhibits long-range colinearity with the other spotted fever group rickettsia genomes, except for a large fragment specific to r. massiliae that contains 14 tra genes presumably involved in pilus formation and conjugal dna transfer. we demonstrate that the tra re ... | 2007 | 17916642 |