Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| spotted-fever-group rickettsioses in north asia. | 2004 | 15051294 | |
| 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 |
| histopathologic features of and lymphoid populations in the skin of patients with the spotted fever group of rickettsiae: southern africa. | 2004 | 15009388 | |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| spotted-fever-group rickettsioses in north asia. | 2003 | 14667766 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [study on spotted fever group rickettsiae in guangdong province]. | to explore the existence of spotted fever group rickettsiae (sfgr) in guangdong province. | 2003 | 14521792 |
| 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 |
| the rocky mountain spotted fever group of rickettsias. | 1965 | 14318051 | |
| nonpathogenic rickettsias related to the spotted fever group isolated from ticks, dermacentor variabilis and dermacentor andersoni from eastern montana. | 1963 | 14053295 | |
| factors affecting the growth of rickettsias of the spotted fever group in fertile hens' eggs. | 1962 | 13917322 | |
| immunologic relationships among the spotted fever group of rickettsias determined by toxin neutralization tests in mice with convalescent animal serums. | 1960 | 13798490 | |
| [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 | |
| erythrocyte-sensitizing substances from rickettsiae of the rocky mountain spotted fever group. | 1954 | 13184127 | |
| recovery of a rickettsia of the spotted fever group from microtus pennsylvanicus from virginia. | 1954 | 13167137 | |
| [rickettsia of the rocky mountain spotted fever group and the agent of siberian tick typhus]. | 1953 | 13150106 | |
| a toxic substance associated with the rickettsias of the spotted fever group. | 1953 | 13052922 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| study of biological characteristics of spotted fever group rickettsial genotypes rpa4, dns14, and dns28. | 2003 | 12860698 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| a follow-up study on newly recognized spotted fever group rickettsiae in ticks collected in southern croatia. | 2003 | 12860618 | |
| which spotted fever group rickettsia are present in dermacentor marginatus ticks in spain? | 2003 | 12860616 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| polymerase chain reaction-based diagnosis of mediterranean spotted fever in serum and tissue samples. | a nested polymerase chain reaction (pcr) assay has been developed and used in the diagnosis of fatal and benign cases of mediterranean spotted fever (msf). the test was based on specific primers derived from a rickettsia conorii 17-kd protein gene. a positive signal was obtained from spotted fever group (sfg) and typhus group (tg) rickettsiae. discrimination between sfg and tg rickettsiae was based on a restriction fragment length polymorphism test. other gram-negative bacterial species tested d ... | 2002 | 12389942 |
| the use of the indirect immunoperoxidase test for the serodiagnosis of rickettsial diseases in malaysia. | the indirect immunoperoxidase (hp) test has been used extensively in most government hospitals in malaysia for the serodiagnosis of scrub typhus, murine typhus and tick typhus during the 1990s. the test was used to determine the igg and igm antibody titers in patients' sera for three rickettsial species, ie orientia tsutsugamushi ot; the causative agent of scrub typhus), rickettsia typhi (rt; the causative agent of murine typhus), and tt118 spotted fever group rickettsiae (tt; the causative agen ... | 2002 | 12236431 |
| rickettsia monacensis sp. nov., a spotted fever group rickettsia, from ticks (ixodes ricinus) collected in a european city park. | we describe the isolation and characterization of rickettsia monacensis sp. nov. (type strain, irr/munich(t)) from an ixodes ricinus tick collected in a city park, the english garden in munich, germany. rickettsiae were propagated in vitro with ixodes scapularis cell line ise6. blast analysis of the 16s rrna, the citrate synthase, and the partial 190-kda rickettsial outer membrane protein a (rompa) gene sequences demonstrated that the isolate was a spotted fever group (sfg) rickettsia closely re ... | 2002 | 12200314 |
| determination of genome size and restriction fragment length polymorphism of four chinese rickettsial isolates by pulsed-field gel electrophoresis. | pulsed-field gel electrophoresis (pfge) was used to determine the genome size and the restriction fragment length polymorphism (rflp) of four new chinese isolates of spotted fever group (sfg) rickettsiae. the genome size of the isolates ha-91, bj-90, 054 and 036 was 1,253 kb, 1,236 kb, 1,272 kb, and 1,272 kb, respectively. the isolates 054 and 036 had identical rflp profiles. all the isolates differed in the properties under study from the so far known sfg rickettsiae. the unique rflp profiles o ... | 2002 | 12197631 |
| first detection of spotted fever group rickettsiae in ixodes ricinus from italy. | ixodes ricinus from italy were examined for the first time to detect whether rickettsiae were present. using molecular methods, we detected three different spotted fever group rickettsiae, including rickettsia helvetica. our results raise the possibility that bacteria other than r. conorii are involved in rickettsial diseases in italy. | 2002 | 12194779 |
| evaluation of antibiotic susceptibilities of three rickettsial species including rickettsia felis by a quantitative pcr dna assay. | rickettsiae grow only intracellularly, and the antibiotic susceptibilities of these bacteria have been assessed by either plaque, dye uptake, or immunofluorescence assays, which are time-consuming. we used a quantitative pcr (with the lightcycler instrument) to assess the levels of inhibition of rickettisa felis, r. conorii, and r. typhi dna synthesis in the presence of various antibiotics. we established the kinetics of rickettsial dna during growth and showed that r. conorii grows more quickly ... | 2002 | 12183224 |
| evidence of spotted fever group rickettsiae in state of rio de janeiro, brazil. | ticks were obtained from dogs from february to september of 1999 at weekly intervals, in the county of piraí, state of rio de janeiro. four hundred seventy four ixodids were taxonomically identified, 103 amblyomma cajennense, seven amblyomma ovale, 209 rhipicephalus sanguineus, and 155 amblyomma sp. an hemolymph test associated with giemsa's stain revealed two specimens in 163 ticks tested (r. sanguineus and amblyomma sp), containing rickettsia-like organisms. direct immunofluorescence verified ... | 2002 | 12163909 |
| rickettsia aeschlimannii: a new pathogenic spotted fever group rickettsia, south africa. | 2002 | 12141981 | |
| characterization of spotted fever group rickettsiae detected in dogs and ticks in okinawa, japan. | spotted fever group (sfg) rickettsial dnas were detected in 2.4% of 340 canine blood samples and a pool of 84 tick pool samples (229 ticks) collected in okinawa, japan by pcr using a citrate synthase and an sfg rickettsial 190-kda surface antigen gene primer pair. the sequences of both genes from canine blood and tick samples showed high levels of similarity with those of rickettsiajaponica and several sfg rickettsiae (r. aeschlimannii, r. massiliae, r. rhipicephali and bar-29 strain). phylogene ... | 2002 | 12061628 |
| phylogenetic analysis of spotted fever group rickettsiae isolated from ticks in japan. | eight spotted fever group (sfg) rickettsiae isolated from ticks in japan were classified by phylogenetic analysis based on the nucleotide sequences of both the citrate synthase-encoding gene (glta) and 190-kda antigen-encoding gene (rompa). in the phylogenetic tree of glta, strains dt-1 and fla-1 isolated from the dermacentor taiwanensis and haemaphysalis frava ticks, respectively, were placed as rickettsia japonica, and strains io-1, io-2, io-25, im-1 and ip-2 from genus ixodes ticks were place ... | 2002 | 12061626 |
| [isolation and identification of hn-98 strain of spotted fever group rickettsiae]. | one strain of rickettsiae was isolated from a patient with unknown fever from qiongzhong county in hainan province in 1998, using embryonated hen eggs and proved to be the member of rickettsiae by the methods of morphology. it was named hs-98 strain after the name of the place and the year it was isolated. | 2000 | 11860785 |
| detection and identification of spotted fever group rickettsiae in dermacentor ticks from russia and central kazakhstan. | 2001 | 11837647 | |
| [spotted fever group rickettsial disease in argentinean travelers]. | during 1996, four patients that returned from south africa suffering from rickettsiosis were attended at the traveler's medicine practice of our hospital. all of them presented fever, headache and cutaneous scar. one of these presented maculopapular rash, while the rest developed a vesicular rash. the weil-felix reaction was negative and the immunofluorescence test for rickettsia conorii was positive in all cases. none of the patients remembered having been bitten by any insects, however all of ... | 2001 | 11813063 |