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reverse transcriptase pcr amplification of rickettsia typhi from infected mammalian cells and insect vectors.we developed a reverse transcriptase pcr assay to detect expression of 120- and 17-kda antigen genes in rickettsia typhi. infected vero cell and flea rnas were reverse transcribed by using random hexamers. the cdna was amplified by using high concentrations of primer and template in an inexpensive, nonradioactive assay.19989620425
septic shock and multiorganic failure in murine typhus. 19989629982
detection of point mutations in rpob gene of rifampin-resistant rickettsia typhi.the rpob gene of rifampin-resistant rickettsia typhi (rif mutant) and wild-type r. typhi were sequenced and compared. the rif mutant rpob had three nucleotide substitutions, which resulted in amino acid changes at residues 151, 201, and 271 and may be the basis for the rifampin resistance.19989661032
vectors vs. humans in australia--who is on top down under? an update on vector-borne disease and research on vectors in australia.australia has a diversity of vectors and vector-borne human diseases. mosquito-borne arboviruses are of greatest concern, but there are issues with other vector and pathogen systems. mosquitoes were responsible for more than 35,000 cases of ross river virus during 1991-1997. barmah forest virus is increasing nationwide, and unidentified bunyaviruses suspected of causing illness have been isolated. cases of murray valley encephalitis have occurred in 14 of the past 20 years in northern australia. ...19989673928
molecular identification of rickettsia typhi and r. felis in co-infected ctenocephalides felis (siphonaptera: pulicidae).rickettsia typhi and r. felis, 2 closely related rickettsial species, often have been identified in cat fleas, ctenocephalides felis (bouché) from the same geographical location. however, no fleas have been found to be naturally infected concurrently with both rickettsial species. to examine whether one rickettsial species can develop simultaneously with another species in the same flea host, cat fleas, naturally infected with r. felis, were allowed to feed on blood containing r. typhi (ethiopia ...19989701920
murine typhus, portugal. 19989763932
serological studies of an acid-labile o-polysaccharide of proteus vulgaris ox19 lipopolysaccharide using human and rabbit antibodies.in a weil-felix test, sera from patients infected with rickettsia sp. agglutinate proteus ox types of bacteria and proteus lipopolysaccharide (lps) are responsible for the cross-reaction. data on the character of lps of one of the ox group strains, proteus vulgaris ox19, are contradictory, and it remained unclear whether it has an o-polysaccharide (ops) and is thus lps of the smooth type (s) or not (rough-type lps). our studies showed that p. vulgaris ox19 (strain pzh-24) produces a smooth-type ...19989858461
murine typhus in travelers returning from indonesia.we report the first three documented cases of murine typhus imported into europe from indonesia, discuss clues for the diagnosis of the disease, and urge that murine fever be considered in the diagnosis of febrile disease in travelers.19989866749
prevalence of antibodies to rickettsia conorii ricketsia africae, rickettsia typhi and coxiella burnetii in mauritania. 19989928878
serologic testing for human granulocytic ehrlichiosis at a national referral center.an indirect immunofluorescence assay (ifa) was used to identify patients with antibodies reactive to the human granulocytic ehrlichiosis (hge) agent. serum samples collected from clinically ill individuals were submitted to the centers for disease control and prevention by physicians via state health departments from throughout the united states and tested against a panel of ehrlichial and rickettsial pathogens. antibodies reactive to the hge agent were detected in 142 (8.9%) of 1,602 individual ...19999986812
[murine typhus]. 199910201197
murine typhus as a common cause of fever of intermediate duration: a 17-year study in the south of spain.fever of intermediate duration (fid), characterized by a febrile syndrome lasting from 7 to 28 days, is a frequent condition in clinical practice, but its epidemiological and etiologic features are not well described. murine typhus (mt) is a worldwide illness; nevertheless, to our knowledge, no studies describing its epidemiological and clinical characteristics have been performed in the south of spain. also, its significance as a cause of fid is unknown.199910219934
green fluorescent protein as a marker in rickettsia typhi transformation.transformation of rickettsiae is a recent accomplishment, but utility of this technique is limited due to the paucity of selectable markers suitable for use in this intracellular pathogen. we chose a green fluorescent protein variant optimized for fluorescence under uv lights (gfpuv) as a fluorometric marker and transformed rickettsia typhi with an rpob-gfpuv fusion construct. the rickettsiae were subsequently grown in vero cells, and cultures were screened by pcr and restriction fragment length ...199910377106
molecular phylogeny and rearrangement of rrna genes in rickettsia species.it has previously been observed that rickettsia prowazekii has an unusual arrangement of the rrna genes. in this species, the three rrna genes, 16s (rrs), 23s (rrl), and 5s (rrf), are not linked in the typical arrangements for bacteria. rather, the 16s rrna gene has been separated from the 23s and 5s rrna gene cluster, and the 23s rrna gene is preceded by a gene which codes for methionyl-trnaf(met) formyltransferase (fmt). in this study, we screened the genus rickettsia for the fmt-rrl motif in ...199910406115
short report: prevalence of antibodies against spotted fever, murine typhus, and q fever rickettsiae in humans living in zambia.the causative agents of rickettsial diseases (rickettsia conorii, r. typhi, and coxiella burnetii) have been reported throughout the african continent. however, there have been no reports on epidemiologic surveys of these infections in zambia. this study was designed to clarify the prevalence of three rickettsioses in 377 humans in zambia. the seroprevalence of antibodies against r. conorii, r. typhi, and c. burnetii was 16.7%, 5.0%, and 8.2%, respectively. the rates of antibody positivity again ...199910432059
seroepidemiologic survey of orientia tsutsugamushi, rickettsia typhi, and tt118 spotted fever group rickettsiae in rubber estate workers in malaysia.the seroprevalence of orientia tsutsugamushi, rickettsia typhi, and tt118 spotted fever group (sfg) rickettsiae in 300 rubber estate workers in slim river, malaysia was determined in december 1996 and march 1997. in december, which was the wet season, 23.3%, 3.0%, and 57.3% of the population had antibodies detected against the three rickettsiae, respectively. the highest seropositive rate of 40% was detected for single infection with sfg rickettsiae, followed by a rate of 15.3% for both o. tsuts ...199910432060
serological evidence of natural infection of wild rodents (rattus spp and tupaia glis) with rickettsiae in malaysia. 199810437957
serologic study of the prevalence of rickettsiosis in yucatán: evidence for a prevalent spotted fever group rickettsiosis.because of the discovery of a spotted fever group rickettsiosis with signs and symptoms similar to dengue fever in yucatan, mexico, immunofluorescence assay (ifa) serology was performed on sera from 390 persons selected from a representative geographic distribution of rural yucatan to detect antibodies reactive with rickettsia rickettsii, r. akari, a thai strain (tt-118) that is most closely related to a rickettsia identified in amblyomma cajennense ticks in southern texas, and r. typhi. the ifa ...199910497980
identification and molecular analysis of the gene encoding rickettsia typhi hemolysin.rickettsia typhi, the causative agent of murine typhus, grows directly within the host cell cytoplasm, accumulating a large number of progeny, and eventually lyses the cells. typhus group rickettsiae (r. typhi and r. prowazekii) adhere to and lyse human and sheep erythrocytes. however, the molecular mechanism underlying erythrocyte lysis by r. typhi has not been defined. here we describe the cloning and nucleotide sequence analysis of the gene (tlyc) encoding a hemolysin from r. typhi. dna seque ...199910531273
an outbreak of west nile fever among migrants in kisangani, democratic republic of congo.in february 1998, an outbreak of acute febrile illness was reported from the kapalata military camp in kisangani, the democratic republic of congo. the illness was characterized by an acute onset of fever associated with severe headache, arthralgia, backache, neurologic signs, abdominal pain, and coughing. in 1 individual, hemorrhagic manifestations were observed. the neurologic signs included an altered level of consciousness, convulsions, and coma. malaria was initially suspected, but the pati ...199910674664
murine typhus in mexico city. 200010748896
in vitro activities of telithromycin (hmr 3647) against rickettsia rickettsii, rickettsia conorii, rickettsia africae, rickettsia typhi, rickettsia prowazekii, coxiella burnetii, bartonella henselae, bartonella quintana, bartonella bacilliformis, and ehrlichia chaffeensis.in vitro activities of telithromycin compared to those of erythromycin against rickettsia spp., bartonella spp., coxiella burnetii, and ehrlichia chaffeensis were determined. telithromycin was more active than erythromycin against rickettsia, bartonella, and coxiella burnetii, with mics of 0.5 microg/ml, 0.003 to 0.015 microg/ml, and 1 microg/ml, respectively, but was inactive against ehrlichia chaffeensis.200010770788
need to increase awareness among family doctors and medical specialists of rickettsioses as an import disease in non-endemic areas.europeans travelling to (sub)-tropical countries have an increased risk for infections with rickettsia. as serious consequences are associated with delay in specific antibiotic therapy, unequivocal diagnosis of this condition is needed. we focus here on the benefits of early, and consequences of late laboratory diagnosis, and emphasise the need of an increased awareness of rickettsioses among family doctors, as well as medical specialists, in non-endemic areas when evaluating patients with trave ...200010781710
cloning and sequencing of the gene encoding the candidate htra of rickettsia typhi.we screened a phage library of rickettsia typhi with a polyclonal antiserum to clone genes which encode immunogenic proteins of r. typhi. among several clones obtained, one clone codes for a 466-amino-acid protein similar to the heat-shock protein, htra. the deduced rickettsial htra contains a putative signal peptide sequence at the n-terminus, a serine protease-like domain, and two pdz domains. the recombinant protein of rickettsial htra reacted with sera from patients with murine typhus and ts ...200010832972
murine typhus in south texas children.murine typhus is a zoonotic infection caused by rickettsia typhi. this illness used to be endemic in the southeastern and gulf coast of the united states and is now only rarely reported in south texas and southern california. murine typhus causes a febrile illness with headache and rash that has been well-described in adults.200010877169
serological differentiation of murine typhus and epidemic typhus using cross-adsorption and western blotting.differentiation of murine typhus due to rickettsia typhi and epidemic typhus due to rickettsia prowazekii is critical epidemiologically but difficult serologically. using serological, epidemiological, and clinical criteria, we selected sera from 264 patients with epidemic typhus and from 44 patients with murine typhus among the 29,188 tested sera in our bank. these sera cross-reacted extensively in indirect fluorescent antibody assays (ifas) against r. typhi and r. prowazekii, as 42% of the sera ...200010882661
scrub and murine typhus among dutch travellers. 199910885849
ultrastructure of rickettsia rickettsii actin tails and localization of cytoskeletal proteins.actin-based motility (abm) is a mechanism for intercellular spread that is utilized by vaccinia virus and the invasive bacteria within the genera rickettsia, listeria, and shigella. within the rickettsia, abm is confined to members of the spotted fever group (sfg), such as rickettsia rickettsii, the agent of rocky mountain spotted fever. infection by each agent induces the polymerization of host cell actin to form the typical f (filamentous)-actin comet tail. assembly of the actin tail propels t ...200010899876
antibodies to orientia tsutsugamushi, rickettsia typhi and spotted fever group rickettsiae among febrile patients in rural areas of malaysia.a serosurvey was conducted in 1995-97 among 1596 febrile patients from 8 health centres in malaysia for antibodies against orientia tsutsugamushi (ot), rickettsia typhi (rt) and tt118 spotted fever group rickettsiae (sfgr) by using an indirect immunoperoxidase assay. a total of 51.4% patients had antibody against at least 1 of those rickettsiae. antibody to sfgr was most prevalent (42.5%), followed by rt (28.1%) and ot (24.9%). the seroprevalences of antibodies to sfgr, rt or ot alone were 12.4, ...200010974999
establishment of a novel endothelial target mouse model of a typhus group rickettsiosis: evidence for critical roles for gamma interferon and cd8 t lymphocytes.a mouse model of typhus rickettsiosis that reproduces the hematogenous dissemination to the critical target organs, including brain, lungs, heart, and kidneys, primary endothelial and, to a lesser degree, macrophage intracellular rickettsial infection, and typical vascular-based lesions of louse-borne typhus and murine typhus was established. intravenous inoculation of c3h/hen mice with rickettsia typhi caused disease with a duration of the incubation period and mortality rate that were dependen ...200011005205
meningoencephalitis caused by rickettsia typhi. 200011062778
the increasing prevalence of endemic typhus in kuala lumpur and an evaluation of a diagnostic elisa dot test for the detection of antibodies to rickettsia typhi.a seroepidemiology study was done in response to the recent increase of endemic typhus cases diagnosed at university hospital. the serosurvey was based on doctors' request for the weil felix (wf) or the indirect immunoperoxidase (iip) test in pyrexia of unknown origin (puo) patients for the years 1991 to 1997. over the 7 years, we found that the incidence of endemic typhus is increasing with gender (male:female = 2:1), age (20-40 years) and race distribution (indians > malay > chinese) that refl ...200011063173
rickettsia typhi seroprevalence among children in the southeast united states. tick-borne infections in children study (ticks) group. 200011099097
clinical, laboratory, and epidemiologic features of murine typhus in 97 texas children.to document the clinical, laboratory, and epidemiologic characteristics of pediatric patients with murine typhus.200111231808
pseudogenes, junk dna, and the dynamics of rickettsia genomes.studies of neutrally evolving sequences suggest that differences in eukaryotic genome sizes result from different rates of dna loss. however, very few pseudogenes have been identified in microbial species, and the processes whereby genes and genomes deteriorate in bacteria remain largely unresolved. the typhus-causing agent, rickettsia prowazekii, is exceptional in that as much as 24% of its 1.1-mb genome consists of noncoding dna and pseudogenes. to test the hypothesis that the noncoding dna in ...200111319266
[ehrlichiosis infection prevalence in spain or cross reactions]. 200111333754
[murine typhus infected in oku-etsu area, fukui prefecture].a 15-year-old girl, high school student, became febrile (38-39 degrees c) with chills, sore throat and cough on april 20, 1994. until the onset, she was healthy and she had been camping with her classmates in a wooded mountainous area in oku-etsu, fukui prefecture. she consulted a local clinic on april 21 and bacampicillin was initially administered and then changed to cefaclor on april 23. however, high body temperature continued and a maclopapular rash appeared on her face on april 24 and grad ...200111357325
prevalence of vectors of the spotted fever group rickettsiae and murine typhus in a bedouin town in israel.a survey of the vectors of spotted fever group rickettsiae and of murine typhus was carried out in rahat, a bedouin town in the negev desert, where the diseases are endemic. houses with known cases of spotted fever group rickettsiae or murine typhus were compared with those without reported clinical cases. a neighboring jewish community, lehavim, where no cases of spotted fever group rickettsiae and murine typhus were reported in recent years, was used as a control. in the houses of patients wit ...200111372975
[fever and calf tenderness after travel in thailand: murine typhus and deep vein thrombosis].a 37-year-old german fell ill with fever and diffuse headaches 3 weeks after flying to thailand for a holiday. because of increasing sickness he began his return (13 h by train then 11 h by plane). besides a temperature of 39.3 degrees c he presented with a unproductive cough and pain in his left calf. on examination there were no other pathological findings than a borderline tachycardia, mild hypotension and signs of dehydration.200111450623
serological evidence for the continued presence of human rickettsioses in southern india.rickettsiosis is generally believed to have disappeared from many parts of india. however, the serological testing of 37 residents of southern india who presented with fever of unknown aetiology in 1996-1998 confirmed that spotted fever, epidemic/endemic typhus and scrub typhus continue to occur in southern india. the epidemiology and magnitude of the problem need to be evaluated.200111454249
lack of association between kawasaki syndrome and infection with rickettsia conorii, rickettsia typhi, coxiella burnetii or ehrlichia phagocytophila group.the etiology of kawasaki syndrome (ks) is unknown. rickettsiae, intracellular microorganisms that invade the vascular endothelium, might cause ks.200111465844
phylogeny of rickettsia spp. inferred by comparing sequences of 'gene d', which encodes an intracytoplasmic protein.'gene d' is the ps120-protein-encoding gene, first described in rickettsia conorii and rickettsia japonica. sequence analysis of a 3030 bp fragment of 'gene d' in 24 representatives of the genus rickettsia was carried out to complete phylogenetic analyses previously inferred by comparison of gene sequences encoding citrate synthase, 17 kda antigen and rompa and rompb. the phylogenetic relationships between rickettsiae were inferred from the comparison of both the gene and the derived protein seq ...200111491333
rickettsial infection in murine models activates an early anti-rickettsial effect mediated by nk cells and associated with production of gamma interferon.natural killer (nk) cell activity was significantly increased on days 2-6 of infection in the rickettsia conorii-infected c3h/hen mice and on day 2 in the rickettsia typhi-infected c57bl/6 mice. depletion of nk cell activity utilizing anti-nk1.1 monoclonal antibody enhanced the susceptibility of normally resistant c57bl/6 mice to infection with r. typhi, and depletion of nk cell activity with antibody to asialo gm1 enhanced the susceptibility of c3h/hen mice to infection with r. conorii. serum g ...200111504408
development of a new epitope tag recognized by a monoclonal antibody to rickettsia typhi.the epitope recognized by a mouse monoclonal antibody (mab) to the crystalline surface layer protein of rickettsia typhi, srt10, was mapped to 10 amino acid residues (srtag tfigaiatdt). the oligonucleotide sequence covering the epitope recognized by srt10 was inserted into a mammalian expression vector together with multiple cloning sites. when the srtag was fused in frame to the coding region of the ncc27/clic1 gene and expressed in mammalian cells, the mab srt10 could detect the tagged protein ...200111570498
the evidence for rickettsial disease arising in new zealand.to describe the first cases of serologically proven riskettsial disease reported in non-travelling new zealanders.200111589433
serologic and molecular evidence of coinfection with multiple vector-borne pathogens in dogs from thailand.forty-nine dogs from thailand were evaluated for serologic evidence of exposure or polymerase chain reaction (pcr) evidence of infection with vectorborne pathogens, including ehrlichia sp. (ehrlichia canis, ehrlichia chaffeensis, ehrlichia equi, and ehrlichia risticii), bartonella vinsonii subsp. berkhoffi (bvb), spotted fever group (sfg) rickettsiae (rickettsia rickettsii), typhus group (tg) rickettsiae (rickettsia canada, rickettsia prowazekii, and rickettsia typhi), and babesia sp. (babesia c ...200111596732
evidence of rodent-associated bartonella and rickettsia infections among intravenous drug users from central and east harlem, new york city.we tested serum samples collected in 1997 and 1998 from a cohort of 204 injection drug users (idus) recruited from central and east harlem, new york city, new york, for antibodies reactive with seven rickettsial or bartonella spp. antigens. rodent-associated bartonella elizabethae and rickettsia akari were the primary etiologic agents of interest. the testing panel also included bartonella henselae, bartonella quintana, rickettsia prowazekii, rickettsia rickettsii, and rickettsia typhi. the high ...200111791987
rickettsia typhi infection in childhood.rickettsia typhi infection (murine typhus) is generally underdiagnosed in childhood, as clinical presentations are often non-specific. we present the manifestations in nine children hospitalized in the department of paediatrics of the university hospital, heraklion, crete, over a 3-y period from 1998 to 2000. titres > 1:400 for igm and >1:960 for igg and/or a fourfold increase in a second sample were considered strongly suggestive of acute infection. children presented with prolonged fever, hepa ...200211883820
rickettsia typhi infection presenting as subacute meningitis.we report two children with rickettsia typhi infection presenting with mild central nervous system manifestations and pleocytosis in cerebrospinal fluid. murine typhus should be included in the differential diagnosis of meningoencephalitis in children who are residents of endemic areas.200211952082
rickettsia-macrophage interactions: host cell responses to rickettsia akari and rickettsia typhi.the existence of intracellular rickettsiae requires entry, survival, and replication in the eukaryotic host cells and exit to initiate new infection. while endothelial cells are the preferred target cells for most pathogenic rickettsiae, infection of monocytes/macrophages may also contribute to the establishment of rickettsial infection and resulting pathogenesis. we initiated studies to characterize macrophage-rickettsia akari and -rickettsia typhi interactions and to determine how rickettsiae ...200211953398
murine typhus poorly responsive to ciprofloxacin: a case report. 200212044280
ownership of cats or dogs does not increase exposure to rickettsia typhi.in the united states, murine typhus (rickettsia typhi) is endemic in southern california and south texas. evidence indicates the natural host/vector system is the opossum and cat flea, the most common flea on both cats and dogs, and speculation suggests that pet contact may pose a risk for r typhi exposure. serum from 140 subjects was tested for rickettsial antibodies by an enzyme-linked immunosorbent assay that used an r typhi antigen. each subject was asked about pet contact status and placed ...200212073903
prevalence of rickettsia conorii and rickettsia typhi infections in the population of northern greece.seroepidemical surveys concerning the prevalence of rickettsia conorii and rickettsia typhi have never been studied in northern greece. we examined 1,584 sera samples from residents of northern greece for the detection of antibodies to r. conorii and to r. typhi by means of immunofluorescence assay. in addition, we compared the prevalence of rickettsial infections among the demographic variables of sex, age, occupation, and area of residence. antibodies to r. conorii and r. typhi were found in 1 ...200212135273
fourteen-year seroepidemiological study of zoonoses in a greek village.a seroepidemiological study carried out in a high-risk village in crete in 1985-1987 and 1998 showed that although the awareness of the people concerning zoonoses had increased during this period, the situation did not improve: there was a significant increase of the spread of seroprevalence in time and space of coxiella burnetii, rickettsia typhi, brucella sp., and entamoeba histolytica. toxoplasma gondii, rickettsia conorii, borrelia burgdorferi, echinococcus granulosus, leishmania sp., and fa ...200212135274
evidence of rickettsia typhi and the potential for murine typhus in jayapura, irian jaya, indonesia.murine typhus (etiologic agent: rickettsia typhi) is endemic to indonesia, especially on the highly populated island of java. a survey of rodents from irian jaya, the eastern-most province of indonesia, indicated striking geographic variation in risk factors associated with murine typhus. murid rodents (n = 112) collected from two villages in the arso district of northeastern irian jaya, were found to be free of ectoparasites normally associated with transmission of r. typhi (i.e., xenopsylla ch ...200212164301
murine typhus in greece: epidemiological, clinical, and therapeutic data from 83 cases.over a period of 5 years (1993-97), 83 cases of murine typhus were identified and studied in the city of chania, on the island of crete. of these cases, 4.8% were registered in 1993, 19.3% in 1994, 47.0% in 1995, 10.8% in 1996, and 18.1% in 1997. the greatest incidence of the disease occurred during the third trimester of the year. direct contact with rats was noted in 45 (54.2%) of 83 patients. two strains of rickettsia typhi were isolated in cell cultures. the predominant clinical manifestatio ...200212174771
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 ...200212183224
prevalence of antibodies to rickettsia typhi in an area of the center of spain.it was the aim of the present work to evaluate rickettsia typhi antibody prevalence in 'comunidad autónoma de madrid' (cam), an area in the centre of spain. a total of 640 serum samples from the general population were tested by an indirect immunofluorescence assay. specific r. typhi antibodies were found in 44 (6.8%) of the samples. the present survey results demonstrate the occurrence of r. typhi human infections in this area.200112188012
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 ...200212236431
transient monoclonal hypergammaglobulinemia during the course of a rickettsia infection. 200212236573
fulminant japanese spotted fever definitively diagnosed by the polymerase chain reaction method.a 72-year-old man was admitted to the emergency ward in our hospital on july 20, 2001, because of consciousness disturbance, fever, generalized skin eruption, and severe general weakness beginning 7 days previously. physical examination on admission revealed marked systemic cyanosis, erythema, and purpura. laboratory findings indicated disseminated intravascular coagulation (dic) and multiorgan failure (platelet count, 0.9 x 10(4)/micro l; fibrin degradation product, 110 micro g/ml; c-reactive p ...200212373493
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 ...200212389942
molecular and functional analysis of the rickettsia typhi groesl operon.the groesl operon from an obligate, intracellular, gram-negative bacterium rickettsia typhi, the etiologic agent of murine typhus, was cloned and sequenced. the sequence analysis of 2229 bp of the groesl operon reveals two open reading frames of 288 nucleotides (groes) and 1653 nucleotides (groel) separated by 20 nucleotides. the deduced amino acid sequence of r. typhi groes and groel shows a high degree of identity with other bacterial groes and groel. reverse transcriptase-polymerase chain rea ...200212406574
prevalence study of antibody to ratborne pathogens and other agents among patients using a free clinic in downtown los angeles.norway rats (rattus norvegicus) are hosts for various microbes. homeless people who have contact with rats may be at risk of infection by them. the los angeles county department of health services initiated a seroepidemiologic study among patients who used a free clinic in downtown los angeles; 200 serum specimens obtained for other routine assays were tested for antibodies to ratborne pathogens and other agents. the seroprevalence of antibody to hepatitis e virus in this population was 13.6%; t ...200212447746
expression of recombinant proteins of orientia tsutsugamushi and their applications in the serodiagnosis of scrub typhus.in this study, recombinant proteins that encompassed the ad i-ad iii regions of 56 kda immunodominant gene of 2 orientia tsutsugamushi (ot) serotypes; gilliam and ta763 were expressed in escherichia coli. both recombinant proteins exhibited serologic cross-reactivity with the rabbit antisera against various ot serotypes, as evaluated by enzyme-linked immunosorbent assay (elisa), but not against other rickettsial species, including rickettsia typhi, r. prowazekii and tt118 sfg rickettsiae. the fe ...200212458119
aseptic meningitis as a delayed neurologic complication of murine typhus. 200212519359
subcellular localization of rickettsial invasion protein, inva.to understand further the molecular basis of rickettsial host cell invasion, rickettsia prowazekii invasion gene homolog (inva) has been characterized. our previous experiments have shown that inva is an ap5a pyrophosphatase, a member of the nudix hydrolase family, which is up-regulated during the internalization, early growth phase, and exit steps during rickettsial mammalian cell infection. in addition to the molecular characterization, subcellular localization of inva was investigated. inva-s ...200312556155
deep origin of plastid/parasite atp/adp translocases.membrane proteins that transport atp and adp have been identified in mitochondria, plastids, and obligate intracellular parasites. the mitochondrial atp/adp transporters are derived from a broad-specificity transport family of eukaryotic origin, whereas the origin of the plastid/parasite atp/adp translocase is more elusive. here we present the sequences of five genes coding for atp/adp translocases from four species of rickettsia. the results are consistent with an early duplication and divergen ...200312574860
is murine typhus re-emerging in portugal ?murine typhus or endemic typhus is an infectious disease, clinically very similar to epidemic typhus, and caused by rickettsia typhi(sometimes referred to as r. mooseri). murine typhus was fairly common in portugal until the 1940s, when several cases diag199812631783
urban zoonoses caused by bartonella, coxiella, ehrlichia, and rickettsia species.the last half of the 20th century witnessed an increase in the occurrence and recognition of urban zoonoses caused by members of the genera bartonella, coxiella, ehrlichia, and rickettsia, all traditionally considered to be members of the family rickettsiaceae. in recent years, new human pathogens (bartonella elizabethae, bartonella henselae, and rickettsia felis) have been recognized in urban environments. other newly recognized pathogens (ehrlichia chaffeensis and ehrlichia phagocytophila in t ...200112653141
s-adenosylmethionine transport in rickettsia prowazekii.rickettsia prowazekii, the causative agent of epidemic typhus, is an obligate, intracellular, parasitic bacterium that grows within the cytoplasm of eucaryotic host cells. rickettsiae exploit this intracellular environment by using transport systems for the compounds available in the host cell's cytoplasm. analysis of the r. prowazekii madrid e genome sequence revealed the presence of a mutation in the rickettsial metk gene, the gene encoding the enzyme responsible for the synthesis of s-adenosy ...200312730161
rickettsia typhi infection in wild rodents from central spain.when sera from 218 rodents captured in two provinces of central spain were tested, by indirect immunofluorescence, for antibodies to rickettsia typhi, 46 (21.1%) were found to be positive, at titres between 1:20 and 1:320. the seropositives included rodents of each of the five species collected: mus musculus, mus spretus, apodemus sylvaticus, rattus rattus and rattus norvegicus. rickettsia typhi infection appears to be common and widespread among the rodents of central spain.200312831526
detection of r. felis and r. typhi in fleas using monoclonal antibodies.rickettsia typhi and r. felis are flea-transmitted human pathogenic rickettsial species. to investigate the distributional dynamics of these rickettsiae we designed a micro-immunofluorescence assay (mif) using species-specific monoclonal antibodies (mabs) applied to flea cryosections. our assay was performed in less than 3 h and its applicability was demonstrated by the detection of r. typhi in 50 artificially infected human body lice but in none of 50 uninfected lice. with mif, we identified 31 ...200312860628
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 ...200312860687
an experimental model of human body louse infection with rickettsia typhi.murine (endemic) typhus caused by rickettsia typhi, one of the most widely distributed arthropod-borne diseases, is transmitted to humans mainly by the oriental rat flea. the human body louse, pediculus humanus corporis, has been suspected to have a role in the transmission of r. typhi to humans. to evaluate the potential role of pediculus humanus corporis as a vector of murine typhus, we used r. typhi in an experimental model of human body louse infection previously used with r. prowazekii. a r ...200312860699
molecular and functional analysis of the lepb gene, encoding a type i signal peptidase from rickettsia rickettsii and rickettsia typhi.the type i signal peptidase lepb genes from rickettsia rickettsii and rickettsia typhi, the etiologic agents of rocky mountain spotted fever and murine typhus, respectively, were cloned and characterized. sequence analysis of the cloned lepb genes from r. rickettsii and r. typhi shows open reading frames of 801 and 795 nucleotides, respectively. alignment analysis of the deduced amino acid sequences reveals the presence of highly conserved motifs that are important for the catalytic activity of ...200312867468
molecular characterization of the sucb gene encoding the immunogenic dihydrolipoamide succinyltransferase protein of bartonella vinsonii subsp. berkhoffii and bartonella quintana.members of the genus bartonella have historically been connected with human disease, such as cat scratch disease, trench fever, and carrion's disease, and recently have been recognized as emerging pathogens causing other clinical manifestations in humans. however, because little is known about the antigens that elicit antibody production in response to bartonella infections, this project was undertaken to identify and molecularly characterize these immunogens. immunologic screening of a bartonel ...200312874367
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 ...200312875301
seroprevalence of rickettsial infection in commensal rodents and shrews trapped in the bangkok metropolitan area.murine typhus and scrub typhus are important human rickettsial diseases in thailand. small mammals, including many species of rodents and shrews, serve as the reservoir host of rickettsial diseases. rickettsia typhi can be transmitted to humans by fleas causing murine typhus, while infection with orientia tsutsugamushi causing scrub typhus in humans is transmitted by chiggers. the prevalence of rickettsial infection depends on the geographic area. the seroprevalence of antibody to r. typhi and o ...200312924799
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.200312950666
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 ...200312971530
the effect of x-radiation on the multiplication of rickettsia mooseri in embryonate eggs.the multiplication of rickettsia mooseri in fertile eggs is speeded up and quantitatively increased by single dose x-radiation given either 24 hours before or 48 hours after inoculation. this effect is noted at all dosage levels studied, ranging from 100 to 1500 r. the rickettsiostatic effects of high incubation temperature (40 degrees c.) and of streptomycin are neutralized by radiation, but the rickettsiostatic actions of paba, penicillin, and aureomycin are not altered. possible mechanisms of ...195313022869
simultaneous multiplication of two different rickettsiae in the same cell. 195213037746
[development of rickettsiae at the expense of the cytoplasms of the host cells during infection due to rickettsia burnetti, rickettsia orientalis, rickettsia mooseri, rickettsia prowazeki and rickettsia conori]. 195313066944
[comparative studies on rickettsia isolated in cases of epidemic and sporadic typhus]. 195313071646
studies of rickettsial toxins. i. role of hemolysis in fatal toxemia of rabbits and rats. 195413118187
reversible inactivation of typhus rickettsiae. i. inactivation by freezing.rickettsiae that have been frozen and thawed in isotonic salt solutions show greatly decreased toxicity for mice, hemolytic activity, respiration, and infectivity for eggs. all these properties can be partially restored by incubation of the rickettsiae in the presence of dpn and coenzyme a for 2 hours at 34 degrees c. the extent of both inactivation and of subsequent reactivation is markedly affected by the presence of low concentrations of sucrose during the process of freezing and thawing. it ...195413211994
isolation of the rickettsial inhibitor from autoclaved diphosphopyridine nucleotide. 195413221581
the effects of paba derivatives on the multiplication of typhus rickettsiae. 195513233515
resistance of mice with experimental histoplasmosis to infection with rickettsia typhi. 195513242803
studies on resistance to bacterial infections in animals infected with rickettsiae.data are presented, demonstrating that infection with rickettsia typhi brings about a reduction of the death rates and a prolongation of the time of survival in animals subsequently challenged with pasteurella pestis or pasteurella tularensis. this interference with bacterial infection by previous rickettsial infection does not appear immediately after injection of the rickettsiae; it begins to appear around 16 hours after this injection and becomes more marked during the first 96 hours; later i ...195613319590
metabolic studies of rickettsiae. iii. studies of transamination, oxidative phosphorylation and glutamate-2-c14 incorporation by purified suspensions of rickettsia mooseri. 195613345759
vitamin content of purified typhus rickettsiae, tobacco mosaic virus, and coliphage t6. 195613382844
further studies on the effects of x-radiation on the multiplication of rickettsia mooseri in embryonate eggs.the effect of x-rays on the growth of rickettsiae in the embryonate egg was investigated. the intensifying effect of x-radiation of the host on rickettsial growth can be attributed to alterations of the cells of the host that persist at least 7 days. the greatest enhancement of the growth of rickettsiae occurred when moderately infected cells were irradiated. these experiments indicate that x-rays may neutralize or reverse changes in the host that are unfavorable to the growth of rickettsiae. ex ...195713406180
a simple method for cultivation of viruses and rickettsiae in the chorio-allantoic ectoderm of the chick embryo by inoculation via the air sac. 195713463388
reversible inactivation of the toxicity and hemolytic activity of typhus rickettsiae by starvation. 195713481003
[studies on properties of rickettsia mooseri cultured in body lice; preliminary communication]. 195713497183
metabolic studies of rickettsiae. iv. terminal respiratory enzymes in rickettsia mooseri. 195713499415
morphological, chemical, and serological studies of the cell walls of rickettsia mooseri. 195713502312
unstable nucleic acids of rickettsia mooseri. 195813506574
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