Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| using pcr/rflp to detect spotted fever group rickettsia in ticks and rodents collected in ninghua, fujian province. | to study the existence of natural foci of spotted fever in ninghua, fujian province. | 2002 | 12410964 |
| rickettsial infection in dermacentor variabilis (acari: ixodidae) inhibits transovarial transmission of a second rickettsia. | this study examined the ability of ticks to maintain multiple species of spotted fever group rickettsiae via transovarial transmission. using a capillary feeding method, previously established ricketisia montana- and rickettsia rhipicephali-infected cohorts of dermacentor variabilis (say) were exposed to r. rhipicephali and r. montana, respectively, in two reciprocal challenge experiments. eggs collected from individual females, for two successive generations, of each cohort were assessed for ri ... | 2002 | 12495176 |
| [cloning and sequence analysis of rompa gene fragment of spotted fever group rickettsiae isolated in china]. | rr 190.70 p-602 n primers were used to amplify the rompa gene fragment of prototype strains (rickettsia sibirica 246 strain and r. parkeri) and chinese strains (bj-90, ha-91 and hlj-054) of spotted fever group rickettsiae (sfgr). the pcr products were cloned into pgem-t vector respectively and sequenced by sanger's dideoxy method. the sequences of the tested strains were compared with the corresponding regions of prototype and reference strains of sfgr. the results showed that the homology of ro ... | 1998 | 12549415 |
| antigenic classification of rickettsia felis by using monoclonal and polyclonal antibodies. | rickettsia felis is a flea-transmitted rickettsia. there is a discrepancy between its reported phylogenic and phenotypic identifications. following the first report of r. felis, it was considered by tests with serologic reagents to be closely related to another recognized flea-transmitted rickettia, r. typhi. subsequently, it appeared to be more closely related to spotted fever group (sfg) rickettsiae by genetic analysis. in the present work, r. felis was studied by microimmunofluorescence (mif) ... | 2003 | 12626446 |
| fort chaffee revisited: the epidemiology of tick-borne rickettsial and ehrlichial diseases at a natural focus. | a retrospective cohort study was conducted among troops training at fort chaffee, arkansas, from may through june 1997, to identify infections caused by tick-borne pathogens. serum samples were tested by ifas for antibodies to selected rickettsia and ehrlichia species and by an investigational eia for spotted fever group rickettsia lipopolysaccharide antigens. of 1,067 guardsmen tested, 162 (15.2%) had antibodies to one or more pathogens. of 93 guardsmen with paired serum samples, 33 seroconvert ... | 2001 | 12653142 |
| molecular evidence for novel tick-associated spotted fever group rickettsiae from thailand. | 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 exam ... | 2003 | 12693853 |
| systemic inflammatory responses in african tick-bite fever. | information regarding the inflammatory response in african tick-bite fever (atbf), an emerging spotted-fever-group rickettsiosis, in international travelers to sub-saharan africa, is scarce. plasma/serum levels of von willebrand factor (vwf), soluble (s) e-selectin, tumor necrosis factor-alpha, interleukin (il)-6, interferon-gamma, il-10, il-13, il-8, rantes, macrophage inflammatory protein-1alpha, and c-reactive protein were studied, at both first presentation and follow-up, in 15 patients with ... | 2003 | 12696016 |
| detection of antibodies against spotted fever group rickettsia (sfgr), typhus group rickettsia (tgr), and coxiella burnetii in human febrile patients in the philippines. | 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 ... | 2003 | 12711823 |
| emerging rickettsioses of the thai-myanmar border. | to investigate the presence of rickettsioses in rural residents of the central thai-myanmar border, we tested the blood of 46 patients with fever. four patients had murine typhus, three patients had scrub typhus, and eight patients had spotted fever group rickettsioses, including the first case of rickettsia felis infection reported in asia. | 2003 | 12737744 |
| antibodies reactive to rickettsia rickettsii among children living in the southeast and south central regions of the united states. | the reported annual incidence of rocky mountain spotted fever in the united states is 2.2 per million, but studies have suggested that human infection with rickettsia rickettsii may be more common. this study estimated the prevalence of antibodies reactive to r rickettsii among children living in the southeastern and south central united states. | 2003 | 12742879 |
| isolation and pcr detection of rickettsiae from clinical and rodent samples in malaysia. | isolation of rickettsiae from patients' blood samples and organ samples of wild rodents from areas with high seroprevalence of rickettsial infections was attempted using cell culture assay and animal passages. l929 mouse fibroblast cells grown in 24 well tissue culture plate were inoculated with buffy coat of febrile patients and examined for the growth of rickettsiae by giemsa, gimenez staining and direct immunofluorescence assay. no rickettsiae were isolated from 48 patients' blood samples. no ... | 2002 | 12757225 |
| identification of the spotted fever group rickettsiae detected from haemaphysalis longicornis in korea. | seven haemaphysalis ticks were found positive in pcr assay of glta gene to detect the spotted fever group (sfg) rickettsiae dna from 100 ticks. the nucleotide sequence of 16s rrna gene was determined from 5 ticks and compared to those of other rickettsia strains. the nucleotide sequence from 4 ticks showed high homologies (99.7 to 100%) with that of r. japonica yh, and that from 1 tick (tick no. 48) was identical with that of r. rickettsii r, suggesting that sfg rickettsiae exists in korea. this ... | 2003 | 12801068 |
| serosurvey among mediterranean spotted fever patients of a new spotted fever group rickettsial strain (bar29). | mediterranean spotted fever is an endemic disease in catalonia, spain. a new spotted fever group (sfg) rickettsial strain (bar29) of unknown pathogenicity for humans was isolated by our group, in 1996, from the dog brown tick, rhipicephalus sanguineus. interestingly, rickettsia conorii was not isolated in this study. the aim of the present study was to assess the possible pathogenic role of the bar29 strain. to this purpose, serum samples from 15 patients with mediterranean spotted fever were ob ... | 2003 | 12803376 |
| spotted fever group rickettsiae in ticks from the masai mara region of kenya. | 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 grou ... | 2003 | 12812343 |
| rickettsioses in swedish travellers, 1997-2001. | from laboratory records, information was collected on all 77 cases of rickettsioses diagnosed in sweden during 1997-2001, 14 of which were diagnosed as belonging to the typhus group and 63 to the spotted fever group. signs of hepatic involvement occurred more frequently in the typhus group. denominators for the number of journeys to different parts of the world were retrieved from a commercial swedish tourist database. the estimated risk of rickettsioses in destinations outside europe varied fro ... | 2003 | 12839153 |
| differentiation of rickettsiae by groel gene analysis. | the nucleotide sequences (534 to 546 bp) of the groel gene, which encodes the 60-kda heat shock protein groel, from 15 rickettsial strains were determined and compared. in the phylogenetic tree created by the unweighted pair group method with arithmetic averages and the neighbor-joining method, rickettsial strains could be distinguished from ehrlichia strains. five spotted fever group strains, four typhus group strains, and six scrub typhus group (stg) strains were differentiated as distinct ent ... | 2003 | 12843026 |
| first isolation and identification of rickettsia conorii from ticks collected in the region of fokida in central greece. | three different spotted-fever group rickettsiae-rickettsia conorii, r. massiliae, and r. rhipicephali-were detected and identified by pcr-restriction fragment length polymorphism analysis in rhipicephalus ticks collected from domestic animals in the fokida region of greece, where a high seroprevalence of antibodies to r. conorii was previously demonstrated. the infection rate of ticks was 1.6%. moreover, r. conorii was isolated from one rhipicephalus sanguineus tick. | 2003 | 12843081 |
| ecology and epidemiology of spotted fever group rickettsiae and new data from their study in russia and kazakhstan. | rickettsiae represent a wide range of pathogenicity from classic and new pathogens to endosymbionts of eukaryotic cells. recent studies of rickettsiae have widened the number of representatives of genus rickettsia, especially in the spotted fever group (sfg). rickettsiae of sfg are tick-borne microorganisms with effective transovarial and transstadial transmission. the main hosts are ticks (dermacentor, rhipicephalus, haemophysalis, ixodes, and amlyomma). strategy of maintenance of tick microorg ... | 2003 | 12860595 |
| rickettsialpox in new york city: a persistent urban zoonosis. | rickettsialpox, a spotted fever rickettsiosis, was first identified in new york city (nyc) in 1946. during the next five years, approximately 540 additional cases were identified in nyc. however, during the subsequent five decades, rickettsialpox received relatively little attention from clinicians and public health professionals, and reporting of the disease diminished markedly. during february 2001 through august 2002, 34 cases of rickettsialpox in nyc were confirmed at cdc from cutaneous biop ... | 2003 | 12860597 |
| rickettsia honei: a spotted fever group rickettsia on three continents. | rickettsia honei (also known as strain tt-118) has been detected on three continents. originally isolated in thailand in 1962 (and confirmed in 2001), it has also been detected on flinders island (australia) in 1993 and in texas (usa) in 1998. on each continent it has been associated with a different species of tick. the original isolate (thai tick typhus strain tt-118) was from a pool of larval ixodes and rhipicephalus ticks. later it was detected in i. granulatus from rattus rattus. its pathog ... | 2003 | 12860601 |
| ultrastructural and genetic evidence of a reptilian tick, aponomma hydrosauri, as a host of rickettsia honei in australia: possible transovarial transmission. | in 1993, a novel rickettsia was isolated from the blood of inhabitants of flinders island, australia, with acute febrile illnesses. this rickettsia was found to be a new species of spotted fever group (sfg) rickettsia, eventually named rickettsia honei. the suspected ectoparasite vector of this rickettsia has yet to be identified. the purpose of this study was to evaluate the presence of this rickettsial species in a suspected tick vector, aponomma hydrosauri, by dna sequencing and electron micr ... | 2003 | 12860602 |
| which spotted fever group rickettsia are present in dermacentor marginatus ticks in spain? | 2003 | 12860616 | |
| a follow-up study on newly recognized spotted fever group rickettsiae in ticks collected in southern croatia. | 2003 | 12860618 | |
| isolation of a rickettsia related to astrakhan fever rickettsia from a patient in chad. | we isolated a novel spotted fever group rickettsia from a patient coming back from chad with fever and a maculopapulous rash. in africa, only six pathogenic spotted fever group rickettsiae have been identified, r. conorii, r. africae, r. akari, r. aeschlimannii, "r. mongolotimonae," and r. felis. our isolate was identified by pcr amplification and sequencing of the 16s rrna (16s rdna), citrate synthase (glta), and rompa (ompa) encoding genes. the 16s rdna, glta, and ompa sequences of the isolate ... | 2003 | 12860619 |
| detection of astrakhan fever rickettsia from ticks in kosovo. | astrakhan fever is a summer spotted fever resembling mediterranean spotted fever, endemic in astrakhan, a region of russia located by the caspian sea. its agent is a spotted fever group rickettsia, member of the rickettsia conorii complex, transmitted to humans by rhipicephalus sanguineus and rhipicephalus pumilio ticks. in summer 2001, french united nations troops in kosovo collected 2 ticks on asymptomatic soldiers (1 r. sanguineus and 1 hyalomma marginatum) and 10 ticks on dogs (7 r. sanguine ... | 2003 | 12860620 |
| molecular evidence of coxiella-like microorganism harbored by haemaphysalis concinnae ticks in the russian far east. | twenty female imago of haemaphysalis concinnae ticks collected from wild vegetation in may of 2001 in the obor region near khabarovsk in the russian far east were studied. dna was extracted with commercially available kits following manufacturer's instructions. we used broad range primers sfg3 and sfg6 proposed for amplification of 16s ribosomal rna gene's portion of spotted fever group rickettsia. initial amplification resulted in positive results in all 20 ticks. direct sequencing of five rand ... | 2003 | 12860630 |
| rickettsial actin-based motility: behavior and involvement of cytoskeletal regulators. | actin-based motility (abm) is employed by spotted fever group (sfg) rickettsiae, such as rickettsia rickettsii, to promote cell-to-cell spread. time-lapse video microscopy revealed that abm is not strictly confined to sfg rickettsiae as typhus group r. typhi moved at approximately the same rate as r. rickettsii (approximately 4 micro m/min), but in a highly erratic fashion. a number of common behaviors were observed between abm of r. typhi and r. rickettsii, such as entrance into plasma membrane ... | 2003 | 12860687 |
| interactions between rickettsiae and dermacentor variabilis ticks: analysis of gene expression. | tick-borne spotted fever group rickettsiae are maintained in nature primarily through transstadial and transovarial transmission in their vector. in the tick, dermacentor variabilis, the infection of, and persistence within, the ovaries are critical steps in the transmission cycle of rickettsiae from one generation to the next. although ixodid ticks can experimentally maintain several species of rickettsiae, often only a single species is maintained transovarially. the molecular mechanisms under ... | 2003 | 12860691 |
| adherence to and invasion of vero cells by recombinant escherichia coli expressing the outer membrane protein rompb of rickettsia japonica. | recombinant escherichia coli expressing the outer membrane protein rompb of rickettsiae on the surface were generated. the dna corresponding to the open reading frame of the ompb gene of a spotted fever group rickettsia, rickettsia japonica, was amplified by polymerase chain reaction. the amplified fragment was inserted between the sal i and the xho i sites of the expression vector pet-22b(+). e. coli bl21(de3) was transformed by the constructed plasmid. the recombinant bacteria expressed a reco ... | 2003 | 12860694 |
| study of biological characteristics of spotted fever group rickettsial genotypes rpa4, dns14, and dns28. | 2003 | 12860698 | |
| serologic evidence of infection with ehrlichiae and spotted fever group rickettsiae among residents of gag island, indonesia. | the causative agents of scrub and murine typhus are considered endemic to indonesia. however, the presence of spotted fever group rickettsiae and ehrlichiae have not been previously described in this country. during an investigation of arthropod-borne diseases on gag island, located northwest of the island of new guinea in eastern indonesia, the prevalence of antibody to the etiologic agents of monocytic ehrlichiosis, spotted fever rickettsiosis, and scrub and murine typhus were determined. anal ... | 2003 | 12875301 |
| prevalence of antibodies to spotted fever group rickettsiae in the region of split (southern croatia). | the prevalence of igg antibodies to spotted fever group rickettsiae (sfg) was investigated by the indirect immunofluorescence assay in a sample of 1207 healthy residents of the central part of southern croatia (eastern coast of adriatic sea). sera obtained from subjects living in three different places of residency (urban, suburban and rural environs of the region) were tested. overall 528 (43.7%) persons had significant antibody titers (1:40 or higher), with a significantly higher prevalence in ... | 2003 | 12889692 |
| cross-protection between distantly related spotted fever group rickettsiae. | two excellent c3h/hen mouse models of spotted fever rickettsioses caused by the distantly related organisms, rickettsia conorii and rickettsia australis, were utilized to evaluate the possibility of the stimulation of broad cross-protective immunity. sublethal infection stimulated complete immunity, that is absence of disease, after challenge with a dose of the heterologous rickettsia that uniformly killed naïve mice. in contrast, heterologous immune sera did not protect mice against a lethal do ... | 2003 | 12922124 |
| sequential changes in hematologic and biochemical parameters in african tick bite fever. | to evaluate the sequential changes and to estimate the frequencies of abnormalities in some commonly measured biological variables in patients with african tick bite fever (atbf), an emerging spotted fever group (sfg) rickettsiosis in international travelers to rural sub-saharan africa. | 2003 | 12925109 |
| a survey for spotted fever group rickettsiae and ehrlichiae in amblyomma variegatum from st. kitts and nevis. | eighty-nine amblyomma variegatum ticks were collected from the islands of st. kitts and nevis in the caribbean and preserved in 70% ethanol or local rum. after being washed in sterile water, their dna was extracted and analyzed by a polymerase chain reaction (pcr) for dna of spotted fever group rickettsiae and ehrlichiae. none of the tested ticks was positive in a pcr assay using the primers 16s ehrd and 16s ehrr for the 16s rrna gene of ehrlichia spp.. forty-one percent of the a. variegatum (36 ... | 2003 | 12932098 |
| spotted fever rickettsiosis in coronel fabriciano, minas gerais state. | we report cases of spotted fever rickettsiosis in coronel fabriciano municipality of minas gerais state, brazil. the cases occurred in may and june of 2000. during this period there were two deaths among children from an area named pedreira in a periurban area of this municipality. in a boy who died with clinical manifestations of brazilian spotted fever, a necropsy revealed the presence of a spotted fever group rickettsia. the serological results confirm the difficulty in the differential diagn ... | 2003 | 12937725 |
| identification of borrelia burgdorferi sensu lato, anaplasma and ehrlichia species, and spotted fever group rickettsiae in ticks from southeastern europe. | prevalence data for tick-borne pathogens are used to assess the risk for human health. in this study the presence and identity of borrelia burgdorferi sensu lato, ehrlichia, anaplasma, and rickettsia species in bulgarian ixodes ricinus ticks and in non- ixodes ticks from turkey and albania was determined by polymerase chain reaction (pcr) and reverse line blot hybridization. in the adult bulgarian ticks, the prevalence of borrelia burgdorferi sensu lato infection was approximately 40%, while bor ... | 2003 | 12938010 |
| emerging rickettsial infections in sri lanka: the pattern in the hilly central province. | to identify different rickettsial infections using a specific immunofluorescent technique in patients clinically diagnosed as 'typhus fever' in the central province of sri lanka, and to define the clinical picture, assess the severity of infection and to determine the pattern of geographical distribution of the infections of the hospital-based patients. | 2003 | 12950666 |
| african tick bite fever. | african tick bite fever is an acute febrile illness that is frequently accompanied by headache, prominent neck muscle myalgia, inoculation eschars, and regional lymphadenitis. the disease is caused by rickettsia africae, a recently identified spotted fever group rickettsia, which is transmitted by ungulate ticks of the amblyomma genus in rural sub-saharan africa and the french west indies. whereas reports on african tick bite fever in indigenous populations are scarce, the number of reported cas ... | 2003 | 12954562 |
| antibody prevalence of orientia tsutsugamushi, rickettsia typhi and tt118 spotted fever group rickettsiae among malaysian blood donors and febrile patients in the urban areas. | the seroprevalence of orientia tsutsugamushi (ot), rickettsia typhi (rt) and tt118 spotted fever group rickettsiae (sfgr) among blood donors and febrile malaysian patients in the urban areas was determined. of the 240 blood donors, 5.4%, 9.2% and 1.7% had either present or previous exposure to ot, rt and sfg rickettsiae, respectively. patients admitted to an urban hospital had high seroprevalences of ot (43.5%) and rt (22.9%), as compared to sfgr (11.6%). antibody levels suggestive of recent inf ... | 2003 | 12971530 |
| a toxic substance associated with the rickettsias of the spotted fever group. | 1953 | 13052922 | |
| [rickettsia of the rocky mountain spotted fever group and the agent of siberian tick typhus]. | 1953 | 13150106 | |
| recovery of a rickettsia of the spotted fever group from microtus pennsylvanicus from virginia. | 1954 | 13167137 | |
| erythrocyte-sensitizing substances from rickettsiae of the rocky mountain spotted fever group. | 1954 | 13184127 | |
| [serological diagnosis of rickettsial diseases of typhus and tick spotted fever group by the hemagglutination method. i. technic for preparing antigen and conducting the test]. | 1957 | 13423199 | |
| immunologic relationships among the spotted fever group of rickettsias determined by toxin neutralization tests in mice with convalescent animal serums. | 1960 | 13798490 | |
| factors affecting the growth of rickettsias of the spotted fever group in fertile hens' eggs. | 1962 | 13917322 | |
| nonpathogenic rickettsias related to the spotted fever group isolated from ticks, dermacentor variabilis and dermacentor andersoni from eastern montana. | 1963 | 14053295 | |
| the rocky mountain spotted fever group of rickettsias. | 1965 | 14318051 | |
| expression analysis of the t-cell-targeting chemokines cxcl9 and cxcl10 in mice and humans with endothelial infections caused by rickettsiae of the spotted fever group. | rocky mountain spotted fever and other related diseases are systemic infections caused by rickettsiae. these obligatory intracellular bacteria target the endothelium, offering an appealing model to study the interactions between endothelial cells and t lymphocytes. we investigated the mrna expression of chemokines known to target cd8+ t cells and cd4(+) t-helper 1 cells in the lungs of c3h/hen mice infected with rickettsia conorii with the purpose of identifying evidence for a role of chemokines ... | 2003 | 14507644 |
| [study on spotted fever group rickettsiae in guangdong province]. | to explore the existence of spotted fever group rickettsiae (sfgr) in guangdong province. | 2003 | 14521792 |
| detection and identification of spotted fever group rickettsiae in ticks collected in southern croatia. | a total of 197 ticks belonging to four species (haemaphysalis punctata, hyalomma marginatum, rhipicephalus bursa and dermacentor marginatus) collected in october 2000 from domestic animals in southern croatia were examined for the presence of rickettsiae by molecular techniques. specific sequences of the rickettsiae were detected in 25 (12.7%) of ticks tested. the prevalence of infection in d. marginatus and h. marginatum ticks was 36.8 and 64.7%, respectively. none of the ticks belonging to the ... | 2002 | 14570128 |
| differential expression of genes in uninfected and rickettsia-infected dermacentor variabilis ticks as assessed by differential-display pcr. | ticks serve as both the vector and the reservoir for members of the spotted fever group rickettsiae. the molecular interaction(s) that results from this close relationship is largely unknown. to identify genetic factors associated with the tick response to rickettsial infection, we utilized differential-display pcr. the majority of upregulation appeared in the infected tissue. we cloned and sequenced 54 differentially expressed transcripts and compared the sequences to those in the genbank datab ... | 2003 | 14573632 |
| experimental infection of lone star ticks, amblyomma americanum (l.), with rickettsia parkeri and exposure of guinea pigs to the agent. | the maculatum agent, rickettsia parkeri (a member of the spotted fever group rickettsiae), was inoculated into a colony of the lone star tick, amblyomma americanum, and followed for two tick generations. in addition, guinea pigs were exposed to the agent by direct injection and by feeding infected ticks on them. eighty (53%) of 150 nymphal a. americanum that were inoculated with suspensions of r. parkeri were positive by hemolymph test and fluorescent antibody test for rickettsial infection when ... | 2003 | 14596284 |
| implications of presumptive fatal rocky mountain spotted fever in two dogs and their owner. | a dog was examined because of petechiation, an inability to stand, pale mucous membranes, a possible seizure, and thrombocytopenia. tick-borne illness was suspected, but despite treatment, the dog died. eight days later, a second dog owned by the same individual also died. the dog was not examined by a veterinarian, but rocky mountain spotted fever (rmsf) was suspected on the basis of clinical signs. two weeks after the second dog died, the owner was examined because of severe headache, fever, n ... | 2003 | 14627095 |
| aponomma hydrosauri, the reptile-associated tick reservoir of rickettsia honei on flinders island, australia. | rickettsia honei is the etiologic agent of flinders island (australia) spotted fever. the tick aponomma hydrosauri is associated with reptiles and is the arthropod reservoir for this rickettsia on flinders island. the rickettsia appears to be maintained in the tick via vertical transmission. of 46 ticks examined, 29 (63%) were positive for spotted fever group rickettsiae by detection of the citrate synthase gene by a polymerase chain reaction (pcr). from the positive tick samples, seven were seq ... | 2003 | 14628950 |
| phylogenetic analysis of spotted fever group rickettsiae based on glta, 17-kda, and rompa genes amplified by nested pcr from ticks in japan. | in order to understand the natural situation of rickettsiae in the ticks in japan, the rickettsial genes, glta gene, rompa gene, and 17-kda gene, were amplified from the ticks by nested pcr. the prevalences of rickettsial glta genes among haemaphysalis formosensis, h. longicornis, h. megaspinosa, ixodes ovatus, h. flava, h. kitaokai, and i. persulcatus were 62, 57, 24, 24, 19, 13, and 10%, respectively; 26% (186/722) being the average. the glta genes amplified from the ticks were classified into ... | 2003 | 14638993 |
| gene sequence-based criteria for identification of new rickettsia isolates and description of rickettsia heilongjiangensis sp. nov. | we propose genetic guidelines for the classification of rickettsial isolates at the genus, group, and species levels by using sequences of the 16s rrna (rrs) gene and four protein-coding genes, the glta, ompa, and ompb genes and gene d. to be classified as a member of the genus rickettsia, an isolate should exhibit degrees of rrs and glta homology with any of the 20 rickettsia species studied of >/=98.1 and >/=86.5%, respectively. a member of the typhus group should fulfill at least two of the f ... | 2003 | 14662925 |
| evaluation of a pcr assay for quantitation of rickettsia rickettsii and closely related spotted fever group rickettsiae. | 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 ... | 2003 | 14662926 |
| spotted-fever-group rickettsioses in north asia. | 2003 | 14667766 | |
| increased detection of rickettsialpox in a new york city hospital following the anthrax outbreak of 2001: use of immunohistochemistry for the rapid confirmation of cases in an era of bioterrorism. | rickettsialpox is a self-limited febrile illness with skin lesions that may be mistaken for signs of potentially more serious diseases, such as cutaneous anthrax or chickenpox. the cluster of cutaneous anthrax cases from bioterrorism in october 2001 likely heightened awareness of and concern for cutaneous eschars. | 2003 | 14676069 |
| survey of ticks collected in mississippi for rickettsia, ehrlichia, and borrelia species. | 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 ... | 2003 | 14714667 |
| rickettsia species infecting amblyomma cooperi ticks from an area in the state of são paulo, brazil, where brazilian spotted fever is endemic. | 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 positiv ... | 2004 | 14715737 |
| fatal spotted fever rickettsiosis, minas gerais, brazil. | the emergence and reemergence of a serious infectious disease are often associated with a high case-fatality rate because of misdiagnosis and inappropriate or delayed treatment. the current reemergence of spotted fever rickettsiosis caused by rickettsia rickettsii in brazil has resulted in a high proportion of fatal cases. we describe two familial clusters of brazilian spotted fever in the state of minas gerais, involving six children 9 months to 15 years of age; five died. immunohistochemical i ... | 2003 | 14718082 |
| [a new type of spotted fever group rickttsiaes detected in the area of changbai mountain, jilin province]. | in order to find out the current situation of tick-borne spotted fever in the area of changbai mountain, jilin province. | 2003 | 14761631 |
| protein interaction mapping on a functional shotgun sequence of rickettsia sibirica. | protein interaction maps can reveal novel pathways and functional complexes, allowing 'guilt by association' annotation of uncharacterized proteins. to address the need for large-scale protein interaction analyses, a bacterial two-hybrid system was coupled with a whole genome shotgun sequencing approach for microbial genome analysis. we report the first large-scale proteomics study using this system, integrating de novo genome sequencing with functional interaction mapping and annotation in a hi ... | 2004 | 14872061 |
| imported spotted fever rickettsioses in united states travelers returning from africa: a summary of cases confirmed by laboratory testing at the centers for disease control and prevention, 1999-2002. | the increasing popularity of foreign travel and ecotourism places travelers at increased risk for certain tick-borne diseases. from 1999 through 2002, 31 cases of imported spotted fever-group rickettsioses (sfgr) in united states residents reporting travel to africa were confirmed by laboratory testing at the centers for disease control and prevention. nineteen patients (61%) reported visiting south africa prior to illness onset. most patients reported fever and one or more eschars; rash was rep ... | 2004 | 14971705 |
| rickettsia parkeri: a newly recognized cause of spotted fever rickettsiosis in the united states. | ticks, including many that bite humans, are hosts to several obligate intracellular bacteria in the spotted fever group (sfg) of the genus rickettsia. only rickettsia rickettsii, the agent of rocky mountain spotted fever, has been definitively associated with disease in humans in the united states. herein we describe disease in a human caused by rickettsia parkeri, an sfg rickettsia first identified >60 years ago in gulf coast ticks (amblyomma maculatum) collected from the southern united states ... | 2004 | 14999622 |
| histopathologic features of and lymphoid populations in the skin of patients with the spotted fever group of rickettsiae: southern africa. | 2004 | 15009388 | |
| detection of antibodies to tick salivary antigens among patients from a region of spain. | with a view to determine which tick species bite humans most frequently in the province of soria (spain) and to know whether these species act as vectors of rickettsia conorii and/or borrelia burgdorferi, we analysed the presence of antibodies against salivary proteins of several tick species and of antibodies against r. conorii and b. burgdorferi sensu lato in 102 samples of serum. the sera were collected from 63 patients who were treated for tick bites at the health services of the soria healt ... | 2004 | 15012027 |
| spotted-fever-group rickettsioses in north asia. | 2004 | 15051294 | |
| evidence of rickettsial and leptospira infections in andean northern peru. | between may and october 2002, a cluster of acute febrile illnesses occurred in the subtropical andean foothills of peru. serologic evidence in villages where disease had been documented showed that the prevalence of igm antibody to leptospira ranged from 6% to 52%, that of igm antibody to spotted fever group (sfg) rickettsia ranged from 10% to 19%, and that of igm antibody to coxiella burnetii from 1% to 15%. measurement of igg antibodies for sfg rickettsiae suggested that this disease was endem ... | 2004 | 15100447 |
| [rickettsioses of the spotted fever-group]. | rickettsioses are among the most frequent causes of febrile diseases in travelers, as shown in several studies in the last years. furthermore, since 1991, with the introduction of new testing methods, 8 new rickettsia species (or new diseases) have been described. typical symptoms of rickettsial infections are high fever, headaches and myalgias, frequently associated with a rash and/or an inoculation eschar ("tache noire") at the site of tick bite. the rapid recognition of a rickettsiosis and th ... | 2004 | 15107984 |
| first serologic evidence of human spotted fever group rickettsiosis in korea. | to investigate the prevalence of spotted fever group rickettsioses in korea, a serosurvey of japanese spotted fever rickettsiosis in patients with acute febrile illness was conducted with an indirect immunofluorescence assay. overall, 19.88% of the patients were found to have polyvalent antibody against rickettsia japonica. this study is the first documentation of spotted fever group rickettsiosis in korea. | 2004 | 15131221 |
| phylogenetic analysis of the francisella-like endosymbionts of dermacentor ticks. | bacterial endosymbionts with significant homology to francisella tularensis (gamma-proteobacteria) have been described from at least five species of ticks in three different genera, including two north american dermacentor species [d. andersoni stiles and d. variabilis (say)]. the evolutionary relationships among the francisella-like endosymbionts (fle) from different hosts and between fle and the arthropod-borne pathogen f. tularensis are not known. a 1,169-base fragment of the 16s rdna and a 7 ... | 2004 | 15185926 |
| molecular evidence for a spotted fever group rickettsia species in the tick amblyomma longirostre in brazil. | 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 rickettsi ... | 2004 | 15185961 |
| [detection of rickettsia hulinii in ticks of the haemaphysalis concinna species in russia]. | the presence of rickettsia hulinii was detected in ticks of the haemaphysalis concinna species in the asiatic part of russia. it was the first detection of these rickettsiae outside the territory of the chinese people's republic. this tick is spread over a broken area and may occur in different regions of eurasia. at present at least 3 rickettsial species of the tick-borne spotted fever group were found in ixodes ticks on the territory of eastern siberia: r. sibirica, known to be the etiological ... | 2004 | 15188554 |
| acute tick-borne rickettsiosis caused by rickettsia heilongjiangensis in russian far east. | an acute tick-borne rickettsiosis caused by rickettsia heilongjiangensis was diagnosed in 13 patients from the russian far east in 2002. we amplified and sequenced four portions of three rickettsial genes from the patients' skin biopsy results and blood samples and showed that the amplified rickettsial genes belong to r. heilongjiangensis, which was recently isolated from dermacentor sylvarum ticks in nearby regions of china. this rickettsia, belonging to subgroup of r. japonica, was previously ... | 2004 | 15200813 |
| fatal spotted fever rickettsiosis, kenya. | we report a fatal case of rickettsiosis in a woman from the united states living in kenya, who had a history of tick exposure. immunohistochemical staining of skin, kidney, and liver demonstrated spotted fever group rickettsiae. the clinical findings, severity, and fatal outcome are most consistent with rickettsia conorii infection. | 2004 | 15200829 |
| spotted fever group rickettsiae from ticks captured in sudan. | ticks were collected from ruminants in various areas of sudan in 1998 and 2000. primer pairs of rickettsial citrate synthase gene (glta) and a spotted fever group (sfg) rickettsial 190-kda surface antigen gene (rompa), respectively, were used for identification. polymerase chain reaction (pcr)-positive products were used for dna sequencing. the glta gene was detected in 55% of the ticks examined (57/104). among the 57 ticks studied, 19 were positive for the rompa gene. thus, 18% of the ticks exa ... | 2004 | 15218219 |
| a rickettsia wasp-like protein activates the arp2/3 complex and mediates actin-based motility. | spotted fever group rickettsia are obligate intracellular pathogens that exploit the host cell actin cytoskeleton to promote motility and cell-to-cell spread. although other pathogens such as listeria monocytogenes use an arp2/3 complex-dependent nucleation mechanism to generate comet tails consisting of y-branched filament arrays, rickettsia polymerize tails consisting of unbranched filaments by a previously unknown mechanism. we identified genes in several rickettsia species encoding proteins ... | 2004 | 15236643 |
| prevalence of antibodies to spotted fever group rickettsiae in humans and domestic animals in a brazilian spotted fever-endemic area in the state of são paulo, brazil: serologic evidence for infection by rickettsia rickettsii and another spotted fever group rickettsia. | in serum samples obtained from all the healthy humans, horses, dogs, and donkeys present on three farms in the pedreira municipality, an endemic area for brazilian spotted fever, an indirect immunofluorescence assay (ifa) detected antibodies against rickettsia rickettsii in 17 (77.3%) horses, 5 (31.3%) dogs (titers ranging from 64 to 4,048), and none of 4 donkeys or 50 humans. five canine and eight equine sera with high antibody titers to r. rickettsii were also tested by ifa against r. bellii, ... | 2004 | 15238696 |
| comparison of immunofluorescence, western blotting, and cross-adsorption assays for diagnosis of african tick bite fever. | in testing paired serum samples from 40 consecutive cases of african tick bite fever, we detected diagnostic antibodies against spotted fever group rickettsiae in 45% of the patients by immunofluorescence assay (ifa) and in 100% of the patients by western blotting (wb) (p < 0.01). a specific diagnosis of rickettsia africae infection could be established in 15% of the patients by ifa and in 73% of the patients by a combination of wb and cross-adsorption assays (p < 0.01). | 2004 | 15242958 |
| ultrastructure of a japanese rickettsial strain genetically identified as rickettsia helvetica which was originally found in europe. | a rickettsial strain io-1 has been isolated from a tick, ixodes ovatus, in japan and genetically identified as rickettsia helvetica, a member of the spotted fever group rickettsiae. ultrastructural observations were made on the microorganism. the ultrastructure of r. helvetica io-1 appeared to be generally the same as that previously shown for other rickettsiae of the spotted fever and typhus groups. the rickettsiae were primarily found free in the cytoplasm of l929 cultured cells. occasionally, ... | 2004 | 15272199 |
| first isolation of rickettsia conorii from humans in the trakya (european) region of turkey. | in the trakya region of turkey, located in the european part of the country, presumptive cases of mediterranean spotted fever have been diagnosed and treated every summer since the beginning of the 1990s. the aim of this prospective study was to isolate and identify the rickettsial strains from blood samples of 11 patients and from skin biopsies of 10 of these 11 patients with the diagnosis of spotted fever in the trakya region of turkey in 2003. immunofluorescence assay was performed with acute ... | 2004 | 15278729 |
| t cells mediate cross-protective immunity between spotted fever group rickettsiae and typhus group rickettsiae. | rickettsioses are severe infections caused by obligately intracellular bacteria that preferentially infect the endothelium lining the vasculature. the causative agents, rickettsiae, have been divided according to biological, genetic, and antigenic parameters into 2 main groups: spotted fever and typhus. they have not been thought to stimulate cross-reactive protective immune responses; however, in this study, we show that, in relevant animal models that mimic human rickettsial infections, there ... | 2004 | 15346331 |
| rickettsial infections--a threat to travellers? | recent developments in cell-culture techniques and molecular methods have led to the description of several new rickettsial diseases. an update on these new infections should be of interest to health workers with patients who are international travellers. | 2004 | 15353963 |
| human ehrlichioses in brazil: first suspect cases. | brazilian spotted fever (bsf) rickettsiosis is the most common and recognized of the human rickettsioses in brazil. it is difficult to establish the diagnosis of human rickettsiosis infection by routine microbiologic methods, creating a false idea that rickettsia and ehrlichia infections are rare and without importance. new tick-borne diseases, like human granulocytic anaplasmosis (hga) and human monocytic ehrlichiosis (hme), have been described in many countries. these diseases can present symp ... | 2004 | 15476059 |
| expression of cx3cl1 (fractalkine) in mice with endothelial-target rickettsial infection of the spotted-fever group. | fractalkine (cx3cl1) is a chemokine expressed mainly by endothelial cells, which are the major cellular targets of rickettsiae. we used immunohistochemistry to investigate the normal expression of cx3cl1 in mice and the kinetics of expression of this chemokine throughout the course of lethal and sublethal rickettsial infections in a mouse model of spotted-fever group rickettsioses. the peak of expression of fractalkine on day 3 of infection coincided with the time of infiltration of macrophages ... | 2005 | 15480764 |
| spotted-fever group rickettsia in dermacentor variabilis, maryland. | three-hundred ninety-two adult dermacentor variabilis were collected from six maryland counties during the spring, summer, and fall of 2002. infection prevalence for spotted fever group rickettsia was 3.8%, as determined by polymerase chain reaction. single strand conformational polymorphism (sscp) analysis followed by sequencing indicated that all infections represented a single rickettsial taxon, rickettsia montanensis. | 2004 | 15496254 |
| rickettsia parkeri in amblyomma triste from uruguay. | 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. | 2004 | 15496258 |
| sequence and expression analysis of the ompa gene of rickettsia peacockii, an endosymbiont of the rocky mountain wood tick, dermacentor andersoni. | the transmission dynamics of rocky mountain spotted fever in montana appears to be regulated by rickettsia peacockii, a tick symbiotic rickettsia that interferes with transmission of virulent rickettsia rickettsii. to elucidate the molecular relationships between the two rickettsiae and glean information on how to possibly exploit this interference phenomenon, we studied a major rickettsial outer membrane protein gene, ompa, presumed to be involved in infection and pathogenesis of spotted fever ... | 2004 | 15528527 |
| characterization of spotted fever group rickettsiae in flea and tick specimens from northern peru. | 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: glt ... | 2004 | 15528680 |
| african tick-bite fever: four cases among swiss travelers returning from south africa. | african tick-bite fever (atbf) is a recently described disease belonging to the spotted fever group. it is caused by rickettsia africae, and cases are mainly diagnosed in travelers returning from sub-saharan africa. | 2004 | 15541225 |
| [genetic identification of rickettsiae of the tick-borne spotted fever group, isolated in the foci of tick-borne rickettsiosis]. | a total of 25 rickettsial cultures of the tick-borne spotted fever (tbsf) group from the collection of the research institute of infections in omsk, isolated from different sources in the territory of the russian federation (from the urals to the far east) during the period of 1954-2001) were studied by the methods of genetic analysis. the fragments of the gene coding the outer-membrane protein of 190 kd (ompa) and synthetase citrate (glta) of the rickettsiae under the study were sequenced. 23 i ... | 2004 | 15554312 |
| update on spotted fever group rickettsiae in south africa. | until very recently, mediterranean spotted fever caused by rickettsia conorii was the only spotted fever group (sfg) rickettsioses recognized in southern africa. however, increasing medical awareness of tick-borne infections, together with the introduction of improved isolation methods and the availability of molecular techniques, have led to the identification of several new sfg rickettsioses in the region. african tick bite fever, caused by rickettsia africae, is currently the most important o ... | 2004 | 15631070 |
| detection of a spotted fever group rickettsia in the tick haemaphysalis juxtakochi in rondonia, brazil. | the tick genus haemaphysalis is represented by four species in the new world, of which only the species haemaphysalis leporispalustris has been associated with rickettsiae. the present study reports for the first time the presence of a rickettsia strain in the tick haemaphysalis juxtakochi. a free-living male of h. juxtakochi, collected in the state of rondonia, western amazon, brazil, was subjected to dna extraction and tested by pcr targeting the four rickettsial genes: glta, 17-kda, ompa and ... | 2004 | 15631911 |
| seroepidemiology of spotted fever group and typhus group rickettsioses in humans, south korea. | the prevalence of spotted fever group (sfg) and typhus group (tg) rickettsioses was investigated in 3,362 sera by immunofluorescence assay. the serum samples were obtained from patients with acute febrile episodes in south korea from december 1992 to november 1993. the number of polyvalent positive sera against sfg rickettsial agents at the level of 1: 40 dilution was 269 (8%) in rickettsia sibirica, 482 (14.34%) in r. conorii, and 546 (16.24%) in r. akari. many of the positive sera contained im ... | 2005 | 15665449 |
| a study of'febrile illnesses on the thai-myanmar border: predictive factors of rickettsioses. | we have performed a case-control analysis to determine the significance of clinical, laboratory and epidemiological features as predictive factors of rickettsioses among patients in sangkhla buri, thailand (thai-myanmar border). fifteen serologically-confirmed rickettsiosis patients including spotted fever group (sfg) rickettsioses, scrub typhus, and murine typhus were classified as 'cases'; one hundred and sixty-three acutely febrile patients presenting to the same hospital during the same time ... | 2004 | 15689083 |
| spotted fever group and typhus group rickettsioses in humans, south korea. | the presence of the nucleic acid of the spotted fever group (spg) and typhus group (tg) rickettsiae was investigated in 200 serum specimens seropositive for sfg rickettsiae by multiplex-nested polymerase chain reaction with primers derived from the rickettsial outer membrane protein b gene. the dna of sfg, tg, or both rickettsiae was amplified in the 24 serum specimens, and sequence analysis showed rickettsia conorii, r. japonica, and r. felis in the specimens. r. conorii and r. typhi were found ... | 2005 | 15752441 |