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[application of pcr and related techniques in the examination of orientia tsutsugamushi].with the application of pcr technique in the medical field, pcr and its related techniques have made progress on detecting orientia tsutsugamushi, which have played an important role in the early diagnosis of tsutsugamushi this paper summarizes the application of pcr and related techniques in detecting disease and pathogen research. this paper summarizes the application of pcr and related techniques in detecting o. tsutsugamushi.201021137321
contrasting spatial distribution and risk factors for past infection with scrub typhus and murine typhus in vientiane city, lao pdr.the aetiological diagnostic of fevers in laos remains difficult due to limited laboratory diagnostic facilities. however, it has recently become apparent that both scrub and murine typhus are common causes of previous undiagnosed fever. epidemiological data suggests that scrub typhus would be more common in rural areas and murine typhus in urban areas, but there is very little recent information on factors involved in scrub and murine typhus transmission, especially where they are sympatric - as ...201021151880
a possibly new rickettsia-like genus symbiont is found in chinese wheat pest aphid, sitobion miscanthi (hemiptera: aphididae).in this study, we investigated rickettsia infection in chinese wheat pest aphid (sitobion miscanthi), moreover detected a possibly new rickettsia-like symbiont, provisionally named as smls(1) (s. miscanthi l type symbiont). the sequence of smls 16s rrna gene is 94% similar to that of its presumed closest relative, orientia tsutsugamushi. if levels of divergence indicate taxonomic distinctiveness, smls probably represents a new genus in the family rickettsiaceae. smls occurs in most populations o ...201021156179
[sero-epidemiologic investigation on tick-borne diseases of humans and domestic animals in zhejiang province.]objective: to investigate the seroprevalence of tick-borne diseases in humans and domestic animals from rural areas of zhejiang province. methods: anji county, jindong district and tiantai county were selected for samples collection according to their geographic locations and historical prevalence of tick-borne diseases. blood samples of humans and domestic animals were collected in the three sites. an indirect immuno-fluorescent antibody test was used to determine the presence of igg antibodies ...201021162818
drug treatment of scrub typhus.scrub typhus is a vector-borne disease caused by the pathogen orientia tsutsugamushi. we review the published literature for evidence on drug treatment in scrub typhus. doxycycline has a proven efficacy in several trials and a meta-analysis, although resistance has been documented in parts of northern thailand. macrolides are equally efficacious and have less adverse effects, but they are expensive. azithromycin is the recommended drug in pregnancy and for children. rifampicin is effective in ar ...201121172901
reporting a case of scrub typhus from andhra pradesh. 201021189708
delay in tetracycline treatment increases the risk of complications in tsutsugamushi disease: data from the japanese diagnosis procedure combination database.tsutsugamushi disease (scrub typhus) is caused by orientia tsutsugamushi, and has been endemic in asia and western pacific islands. though sporadic case reports have described the clinical consequences of this vector-borne disease, data on the actual incidence of complications or mortality are scarce. it also remains unclear how a delay in effective treatments affects the occurrence of complications associated with this rickettsial disease.201121212571
identification of potential hosts and vectors of scrub typhus and tick-borne spotted fever group rickettsiae in eastern taiwan.scrub typhus and tick-borne spotted fever group (sfg) rickettsioses are transmitted by chiggers (larval trombiculid mites) and hard ticks, respectively. we assessed exposure to these disease vectors by extensively sampling both chiggers and ticks and their small mammal hosts in eastern taiwan during 2007 and 2008. the striped field mouse apodemus agrarius pallas (rodentia: muridae) was the most common of the small mammals (36.1% of 1393 captures) and presented the highest rate of infestation wit ...201121223345
transient monoclonal gammopathy in a patient with scrub typhus. 201121240076
molecular epidemiology of orientia tsutsugamushi in cambodia and central vietnam reveals a broad region-wide genetic diversity.scrub typhus is an acute infectious disease caused by an obligate intracellular bacterium orientia tsutsugamushi following the bite of infected trombiculid mites of the genus leptotrombidium. this zoonotic disease is a major cause of febrile illness in the asia-pacific region, with a large spectrum of clinical manifestations from unapparent or mild disease to fatal disease. o. tsutsugamushi is characterized by a very high genomic plasticity and a large number of antigenic variants amongst strain ...201121241829
an autotransporter protein from orientia tsutsugamushi mediates adherence to nonphagocytic host cells.orientia tsutsugamushi, the causative agent of scrub typhus, is an obligate intracellular pathogen whose mechanism of cellular adhesion and invasion is poorly characterized. bioinformatic analyses of two o. tsutsugamushi genomes revealed the presence of a group of genes that encode autotransporter proteins. in this study, we identified 10 autotransporter gene products and categorized them into five groups of orthologs (scaa to scae) based on their sequence similarities. sequence homology was hig ...201121282412
phylogenetic analysis of the 56 kda protein genes of orientia tsutsugamushi in southwest area of korea.this study was conducted to determine which genotypes were present in southwestern korea. nested polymerase chain reaction (pcr) and dna sequence analysis targeting the orientia tsutsugamushi-specific 56-kda protein gene was performed with samples of blood and eschar. of the 69 pcr-positive samples, 61 clustered with the boryong previously isolated in korea. cuh 4-6 had sequence homology of 100% with kato, and cuh 4-3 had homology of 99.8% with kato and formed the kato cluster. cuh 4-57, cuh 4-3 ...201121292894
incidence of rickettsial infection in patients with acute fever in provincial thai army hospitals.scrub typhus is common among patients with acute fever in rural areas of thailand. the authors prospectively recruited patients with acute fever from provincial thai army hospitals. dot-elisa test for scrub typhus was done in hospitals and then compared with standard immunofluorescent assay for diagnosis of scrub typhus. among 178 patients, scrub typhus was diagnosed by immunofluorescent assay in 10 patients (5.61%). the incidence was high in the northeastern and northern regions. dot-elisa gave ...200921302413
gene gain and loss events in rickettsia and orientia species.genome degradation is an ongoing process in all members of the rickettsiales order, which makes these bacterial species an excellent model for studying reductive evolution through interspecies variation in genome size and gene content. in this study, we evaluated the degree to which gene loss shaped the content of some rickettsiales genomes. we shed light on the role played by horizontal gene transfers in the genome evolution of rickettsiales.201121303508
nested polymerase chain reaction on blood clots for gene encoding 56 kda antigen and serology for the diagnosis of scrub typhus.scrub typhus is a zoonotic illness endemic in the asia-pacific region. early diagnosis and appropriate management contribute significantly to preventing adverse outcomes including mortality. serology is widely used for diagnosing scrub typhus. recent reports suggest that polymerase chain reaction (pcr) could be a rapid and reliable alternative. this study assessed the utility of these tests for scrub typhus diagnosis.201121304195
scrub typhus meningoencephalitis occurring during doxycycline therapy for orientia tsutsugamushi.we report on a scrub typhus patient who contracted meningoencephalitis during doxycycline administration. this is the first case of scrub typhus in which doxycycline concentrations were measured in serum and cerebrospinal fluid. clinicians should be alerted to the possibility that meningoencephalitis can occur because of inadequate maintenance of serum doxycycline level caused by antacids administered along with doxycycline.201121353950
involvement of ca²+ signaling in intracellular invasion of non-phagocytic host cells by orientia tsutsugamushi.calcium signaling has been implicated in various steps in bacterial pathogenesis. here, we investigated the role of ca(2+) signaling in intracellular invasion of non-phagocytic host cells infected with orientia tsutsugamushi, the causative agent of scrub typhus. the bacteria induced a transient ca(2+) increase in hela cells immediately after infection and the source of the mobilized ca(2+) appears to be intracellular stores, not the extracellular milieu, as determined using extracellular (egta) ...201121362468
genetic typing, based on the 56-kilodalton type-specific antigen gene, of orientia tsutsugamushi strains isolated from chiggers collected from wild-caught rodents in taiwan.orientia tsutsugamushi is the etiological agent of scrub typhus, a mite-borne, febrile illness that occurs in the asia-pacific region. we conducted strain characterization of o. tsutsugamushi isolates from chiggers obtained from rodents based the nucleotide sequence of the 56-kda outer membrane protein gene. with the use of pcr, a total of 68 dna sequences of 56-kda antigen genes were amplified. phylogenetic analysis revealed that there were at least six definable clusters among the 68 isolates: ...201121441323
detection of orientia tsutsugamushi, the causative agent of scrub typhus, in a novel mite species, eushoengastia koreaensis, in korea.to identify potential vector species of scrub typhus in the republic of korea (rok), chigger mites were harvested from wild rodents captured at nine localities in october 2005. the bodies of the chigger mites were individually punctured with a fine pin, squeezed out internal contents, and examined for orientia tsutsugamushi dna by nested polymerase chain reaction. the exoskeleton of associated chiggers was mounted on glass slides with polyvinylalcohol (pva) medium for identification. among 830 i ...201121443412
otalgia and eschar in the external auditory canal in scrub typhus complicated by acute respiratory distress syndrome and multiple organ failure.scrub typhus, a mite-transmitted zoonosis caused by orientia tsutsugamushi, is an endemic disease in taiwan and may be potentially fatal if diagnosis is delayed.201121450057
[sero-epidemiological investigation on rickettsia typhi, bartonella henselae and orientia tsutsugamushi in farmers from rural areas of tianjin, 2007 - 2009.]objective: to study the sero-epidemiological status regarding rickettsia (r.) typhi, bartonella (b.) henselae and orientia (o.) tsutsugamushi in farmers from rural areas of tianjin. methods: field epidemiological surveys were performed in 8 districts (county) of tianjin city from 2007 to 2009. 886 farmers were randomly recruited and their serum samples collected to detect the specific antibodies of r. typhi, b. henselae and o. tsutsugamushi by micro-indirect immunoflorescence (ifa). results: the ...201121457660
subversion of host cell signaling by orientia tsutsugamushi.progress has been made in deciphering the mechanisms on orientia tsutsugamushi-host interaction. the genome sequencing, microarray and proteomic analyses of this ancient bacterium have provided a wealth of new information. this paper reviews the general characteristics of o. tsutsugamushi and recent developments especially in signaling events involved in the bacteria--host interaction.201121458586
isolation and characterization of orientia tsutsugamushi from rodents captured following a scrub typhus outbreak at a military training base, bothong district, chonburi province, central thailand.orientia tsutsugamushi, an obligate intracellular gram-negative bacterium, is the causative agent of scrub typhus, a vector-borne disease transmitted by infected chiggers (trombiculid mite larvae). in 2002, an outbreak of scrub typhus occurred among royal thai army troops during the annual field training at a military base in bothong district, chonburi province, central thailand. this report describes the outbreak investigation including its transmission cycle. results showed that 33.9% of 174 t ...201121460017
kinetics and magnitude of antibody responses against the conserved 47-kilodalton antigen and the variable 56-kilodalton antigen in scrub typhus patients.western blot analysis of orientia tsutsugamushi whole-cell lysates with scrub typhus patient sera has identified at least five protein antigens of o. tsutsugamushi with molecular sizes of 22 kda, 47 kda, 56 kda, 58 kda, and 110 kda. in this study, sera from serial bleedings of 108 patients were used to study the kinetics and the magnitude of specific antibody responses against the 47-kda and 56-kda antigens. recombinant protein of the conserved 47-kda antigen (r47b) or a mixture of truncated 56- ...201121508168
[an outbreak of endemic typhus in baoshan city, yunnan province.]objective: to understand the epidemiologic characteristics of endemic typhus in baoshan city. methods: epidemiological data were collected and characteristics were analyzed. igg antibody (ab) of rickettsia mooseri and orientia tsutsugamushi in serum of patients were tested using both weil-felix and ifa method. the rickettsia mooseri glta gene, rickettsia prowazekii glta gene, orientia tsutsugamushi 56 kda protein gene, sfgr ompa gene, ehrlichia sp. 16s rrna gene and anaplasma sp. 16s rrna gene i ...201121518541
genotype diversity and distribution of orientia tsutsugamushi causing scrub typhus in thailand.scrub typhus caused by antigenically disparate isolates of orientia tsutsugamushi is a widely distributed mite-borne human disease in the asia pacific region. information regarding heterogeneity of the immunodominant 56 kda type specific antigen (tsa) gene is crucial for the design and evaluation of scrub typhus-specific diagnostic assays and vaccines. using ifa and pcr assays, o. tsutsugamushi was detected in fever of unknown origin patients and rodents obtained from 6 provinces of thailand dur ...201121593255
orientia tsutsugamushi stimulates an original gene expression program in monocytes: relationship with gene expression in patients with scrub typhus.orientia tsutsugamushi is the causal agent of scrub typhus, a public health problem in the asia-pacific region and a life-threatening disease. o. tsutsugamushi is an obligate intracellular bacterium that mainly infects endothelial cells. we demonstrated here that o. tsutsugamushi also replicated in monocytes isolated from healthy donors. in addition, o. tsutsugamushi altered the expression of more than 4,500 genes, as demonstrated by microarray analysis. the expression of type i interferon, inte ...201121610853
lack of effect of dexamethasone on growth of orientia tsutsugamushi gilliam in mouse l929 cells.purpose: previous studies and our own clinical experience suggest that concurrent corticosteroid treatment for severe rickettsial disease with multiorgan failure may improve the clinical course or reduce mortality. however, the use of corticosteroids as adjunctive treatment for rickettsial diseases is controversial. we attempted to determine the influences of corticosteroid on the growth of orientia tsutsugamushi in vitro to justify and evaluate the clinical applicability of corticosteroid in ri ...201121623605
medical microbiologyrickettsiae are small, gram-negative bacilli that have evolved in such close association with arthropod hosts that they are adapted to survive within the host cells. they represent a rather diverse collection of bacteria, and therefore listing characteristics that apply to the entire group is difficult. the common threads that hold the rickettsiae into a group are their epidemiology, their obligate intracellular life ...199621413251
analysis of the cross-reactivity of various 56 kda recombinant protein antigens with serum samples collected after orientia tsutsugamushi infection by elisa.abstract. orientia tsutsugamushi, the etiologic agent of scrub typhus, has a highly expressed and immunodominant 56-kd outer membrane protein. this protein is one of the leading candidates for diagnosis and vaccine development for scrub typhus. previous studies using recombinant 56-kd protein (r56s) derived from karp strain (kpr56) in a mouse model have shown good homologous protection but only moderate to poor heterologous protection. we evaluated the cross-reactivity of recombinant 56-kd prote ...201121633035
investigation of anaplasmosis in yiyuan county, shandong province, china.to investigate the situation of anaplasmosis in yiyuan county, shandong province.201121803311
cellular tropism, population dynamics, host range and taxonomic status of an aphid secondary symbiont, smls (sitobion miscanthi l type symbiont).smls (sitobion miscanthi l type symbiont) is a newly reported aphid secondary symbiont. phylogenetic evidence from molecular markers indicates that smls belongs to the rickettsiaceae and has a sibling relationship with orientia tsutsugamushi. a comparative analysis of coxa nucleotide sequences further supports recognition of smls as a new genus in the rickettsiaceae. in situ hybridization reveals that smls is housed in both sheath cells and secondary bacteriocytes and it is also detected in aphi ...201121789197
scrub typhus presenting as acute abdomen.scrub typhus, a zoonosis, is a systemic febrile illness with diverse clinical manifestations. it may also present with signs and symptoms of acute abdomen. we present two serologically confirmed cases of scrub typhus presenting with acute abdomen that were managed conservatively with antibiotics.201121724691
spatial analysis of scrub typhus infection and its association with environmental and socioeconomic factors in taiwan.we analyzed the spatial distribution of human cases of scrub typhus on the main island of taiwan from 2003 to 2008 and implemented an island-wide survey of scrub typhus vectors (trombiculid chiggers) in 2007 and 2008. the standardized incidence rate 'sir' incorporating inter-district variations in population, gender and age was correlated with environmental and socioeconomic variables. higher incidence and sir rates were clustered in the less developed, mountainous regions of central and eastern ...201121703220
broad-coverage molecular epidemiology of orientia tsutsugamushi in thailand.orientia tsutsugamushi, an obligate intracellular bacterium closely related to the genus rickettsia, is the causative agent of scrub typhus, a major cause of febrile illness in rural areas of asia-pacific region. scrub typhus is transmitted by the bite of infected mites of the genus leptotrombidium. the region of the 56-kda tsa gene spanning from variable domain i (vdi) to variable domain iv (vdiv) was sequenced and used for genotyping 77 o. tsutsugamushi samples from human patients confirmed wi ...201121712103
advances in genetic manipulation of obligate intracellular bacterial pathogens.infections by obligate intracellular bacterial pathogens result in significant morbidity and mortality worldwide. these bacteria include chlamydia spp., which causes millions of cases of sexually transmitted disease and blinding trachoma annually, and members of the +¦-proteobacterial genera anaplasma, ehrlichia, orientia, and rickettsia, agents of serious human illnesses including epidemic typhus. coxiella burnetii, the agent of human q fever, has also been considered a prototypical obligate in ...201121833334
coagulation and inflammation in scrub typhus and murine typhus-a prospective comparative study from laos.clin microbiol infect abstract: scrub typhus (caused by orientia tsutsugamushi) and murine typhus (caused by rickettsia typhi) cause up to 28% of febrile episodes in thailand and laos. the current understanding of coagulation and inflammation in the pathogenesis of these clinically very similar vasculotropic diseases is limited. this study compared human in vivo changes in 15 coagulation, inflammation and endothelial activation markers in prospectively collected admission and follow-up samples o ...201122192733
New insight into immunity and immunopathology of Rickettsial diseases.Human rickettsial diseases comprise a variety of clinical entities caused by microorganisms belonging to the genera Rickettsia, Orientia, Ehrlichia, and Anaplasma. These microorganisms are characterized by a strictly intracellular location which has, for long, impaired their detailed study. In this paper, the critical steps taken by these microorganisms to play their pathogenic roles are discussed in detail on the basis of recent advances in our understanding of molecular Rickettsia-host interac ...201221912565
diagnostic accuracy of a loop-mediated isothermal pcr assay for detection of orientia tsutsugamushi during acute scrub typhus infection.there is an urgent need to develop rapid and accurate point-of-care (poc) technologies for acute scrub typhus diagnosis in low-resource, primary health care settings to guide clinical therapy.201121931873
altered sensorium in scrub typhus. 201121941079
bilateral simultaneous facial palsy following scrub typhus meningitis: a case report and literature review.scrub typhus is widely distributed across the asia-pacific region, taiwan included. the clinical manifestations and complications of scrub typhus vary and the illness ranges in severity from mild to fatal. the etiology of facial nerve palsy varies and infectious agents have been associated with this condition. rickettsiae species have, however, rarely been reported as the causative agents. we report the case of a 49-year-old man who had fever, malaise, headache, oligouria and tea-colored urine. ...201122208541
severity predictors in eschar-positive scrub typhus and role of serum osteopontin.we prospectively evaluated severity predictors in terms of host, microorganism, and treatment factors in 153 eschar-positive scrub typhus patients. severity was assessed with the acute physiology and chronic health evaluation (apache) ii score (< 10 versus ≥ 10) and predefined criteria of severe complications. genotypes of orientia tsutsugamushi were determined. independent risk factors for severity (apache ii score ≥ 10) were old age, diabetes mellitus, serum osteopontin > 100 ng/ml, and a grou ...201122049051
differences in clinical features according to boryoung and karp genotypes of orientia tsutsugamushi.scrub typhus is an infectious disease caused by orientia tsutsugamushi. the differences in virulence of o. tsutsugamushi prototypes in humans are still unknown. we investigated whether there are any differences in the clinical features of the boryoung and karp genotypes.201121857951
Endemic scrub typhus-like illness, Chile.We report a case of scrub typhus in a 54-year-old man who was bitten by several terrestrial leeches during a trip to Chiloé Island in southern Chile in 2006. A molecular sample, identified as related to Orientia tsutsugamushi based on the sequence of the16S rRNA gene, was obtained from a biopsy specimen of the eschar on the patient's leg. Serologic analysis showed immunoglobulin G conversion against O. tsutsugamushi whole cell antigen. This case and its associated molecular analyses suggest that ...201121888791
A rickettsia genome overrun by mobile genetic elements provides insight into the acquisition of genes characteristic of an obligate intracellular lifestyle.We present the draft genome for the Rickettsia endosymbiont of Ixodes scapularis (REIS), a symbiont of the deer tick vector of Lyme disease in North America. Among Rickettsia species (Alphaproteobacteria: Rickettsiales), REIS has the largest genome sequenced to date (>2 Mb) and contains 2,309 genes across the chromosome and four plasmids (pREIS1 to pREIS4). The most remarkable finding within the REIS genome is the extraordinary proliferation of mobile genetic elements (MGEs), which contributes t ...201222056929
a rapid, sensitive and reliable diagnostic test for scrub typhus in china.to evaluate the performances for detection of igm and igg antibodies to orientia. tsutsugamushi (ot) using a gold conjugate-based rapid diagnostic test (rdt).201122120796
Emergence of Schoengastiella ligula as the vector of scrub typhus outbreak in Darjeeling: has Leptotrombidium deliense been replaced?Following a suspected outbreak of scrub typhus in Kurseong, Darjeeling, the Armed Forces Medical College, Pune was requested by the National Institute of Epidemiology and the State authorities to undertake investigation of the ongoing scrub typhus outbreak and suggest containment measures.201121941043
comparison of a rapid diagnostic test and microimmunofluorescence assay for detecting antibody to orientia tsutsugamushi in scrub typhus patients in china.to evaluate the detection of igm and igg antibodies to orientia tsutsugamushi (o. tsutsugamushi) by rapid diagnostic test (rdt) and microimmunofluorescence assay (mifa).201121914549
[sequence analysis subtyping of the 56-kda protein-encoding gene of karp-type orientia tsutsugamushi isolated in scrub typhus cases].to determine the karp-type orientia tsutsugamushi subtype in northern japan, i.e., yamagata, niigata, and akita prefectures, we analyzed the partial nucleotide sequence of the 56-kda protein-encoding gene of 30 isolates from scrub typhus cases. based on sequencing results, we classified isolates into two groups of 27 and 3 isolates. nucleotide sequences of 27 isolates were homologous to the yeo-joo strain, classified as a jp-1 subtype. the three isolates were each homologous to a stain of cmm1, ...201122250452
orientia tsutsugamushi in human scrub typhus eschars shows tropism for dendritic cells and monocytes rather than endothelium.scrub typhus is a common and underdiagnosed cause of febrile illness in southeast asia, caused by infection with orientia tsutsugamushi. inoculation of the organism at a cutaneous mite bite site commonly results in formation of a localized pathological skin reaction termed an eschar. the site of development of the obligate intracellular bacteria within the eschar and the mechanisms of dissemination to cause systemic infection are unclear. previous postmortem and in vitro reports demonstrated inf ...201222253938
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