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Objective:To investigate the infection of spotted fever group Rickettsiae (SFGR) and Rickettsia mooseri ( R.mooseri) of wild rodents in the field of plague foci in Western Yunnan. Methods:The DNA of liver samples of 2 512 wild rodents captured from the plague foci in Lianghe County, Jianchuan County and Yulong County in Western Yunnan from 2015 to 2016 was extracted by magnetic bead method, and the heat shock protein groEL gene primers were used for nested PCR amplification. Gene sequence splicing and Blast homology comparison were performed using DNAStar 7.1 software and GenBank of the National Center for Biotechnology Information (NCBI) of the United States, respectively, and DNAStar 7.1 and MEGA 6.0 softwares were used to construct phylogenetic trees.Results:The wild rodents infected with SFGR were Mus pahari, Rattus steini, Crocidura attenuata and Suncus murinus (one for each), with a total infection rate of 0.16% (4/2 512); no R.mooseri infection was detected. The SFGR infection rates of wild rodents in the plague foci of Lianghe County and Jianchuan County were 0.49% (3/611) and 0.10% (1/1 029), respectively; no SFGR infection was detected in the wild rodents in the plague foci of Yulong County. The homology analysis showed that the homology between SFGR positive samples and reference sequences was 95.45%-100.00%; some of the groEL gene sequences were highly similar among the four positive samples, and the homology was 89.60%-97.40%. Sequence evolution analysis showed that the sequences of three SFGR positive samples from the plague focus in Lianghe County were clustered in the same branch, and the homology reached 94.40%-97.40%; one positive sample sequence from the plague focus in Jianchuan County was clustered in one branch. Conclusion:SFGR infection rate of wild rodents in the field of plague foci in Western Yunnan is low, and no R.mooseri infection is found.
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Introduction: Febrile thrombocytopenia is thethrombocytopenia associated with febrile illness. Thecommon causes are dengue, rickettsiae, malaria, typhoid,septicemia and in some cases undifferentiated fever. Thepresent study was intended to know the underlying etiology offebrile thrombocytopenia cases admitted to our hospital, thevarious presentations and relationship between platelet countand bleeding manifestation and prognosis.Material and methods: The study was conducted on 855patients aged 18 years and above who presented with feverand thrombocytopenia and were admitted in MVJ MedicalCollege and Research Hospital, Hoskote, Bengaluru ruraldistrict from January 2016 to December 2018.Results: A total of 855 patients of febrile thrombocytopeniawere admitted to our hospital during study period. Majority ofpatients were in the age group of 18 to 40 years with male tofemale ratio of 1.15: 1. Most of the cases presented during themonths of July to September. Commonest clinical presentationwere fever (100%), myalgia (86.5%) and headache (84.7%).In the majority of patients, thrombocytopenia was transient,present for 2 – 3 days, but bleeding manifestations were seenin 24.3% of patients. Petechiae (14%) was the commonestbleeding manifestation. 691 (80.81%) patients had plateletcount between 50000 to 1.5 lakh/mm3 and 164 (19.18%)cases had platelet count less than 50000/mm3 Only 5.6%had need for platelet transfusion. Dengue (51.9%) was thecommonest cause of thrombocytopenia followed by rickettsialfever (27.7%). In 15.6% of patients the etiology could not beascertained.Conclusion: Febrile thrombocytopenia is the most commoncause for admission to the hospital which requires extensiveevaluation and prompt management.
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Objective To investigate rickettsiae infection from host animals and vector arthropods in some areas of Yunnan Province. Methods Rat clip and cage traps were used to capture mice. Chiggers from body surface of mice and ticks from body surface of farm cattle were collected. DNAs were extracted from mice spleens, chiggers and ticks. Rickettsiae groEL segment were amplified by nested-polymerase chain reaction (nPCR), sequenced to analyze the homology with other known sequences. Results A total of 410 samples were collected for rickettsiae groEL segment detection with nPCR and 19 samples (4.63%) showed positive for rickettsiae groEL segment . Among them, 2.68%(11/410)were positive for Orientia tsutsugamsushi (Ot) groEL segment, and 1.22%(5/410)were positive for spotted fever group rickettsia (SFGR) groEL segment, and 0.49%(2/410)were positive for rickettsia mooseri (Rm) groEL segment, and 0.24%(1/410)were positive for rickettsia endosymbiont(Re) groEL segment. When analyzed the homology with other known sequences, 11Ot strains with 93.6%-100% similarities among them in this study shared the highest similarity with other Ot strains from GenBank respectively, reached up to 96.1%-100%; The groEL segments of 5 SFGR strains with 92.1%-99.5% similarities among them in this study shared highest similarity with other SFGR strains from other GenBank respectively, reached up to 98.9%-100%; In this study groEL segments of 2 Rm strains all showed 100% similarity with Wilmington strain (GenBank No:AE017197); One groEL segment of Re showed 98.9% similarity with Re strain (GenBank No:EU435143). Conclusion There were kinds of rickettsiaes infection in host animals and vector arthropods in Yunnan Province, so the monitoring and prevention of the Rickettsiosis should be strengthened.
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Doenças causadas por rickettsias tem ampla distribuição geográfica e estão associadas a artrópodes hematófagos. Rickettsia rickettsii é espécie mais patogênica do Grupo da Febre Maculosa (GFM) e responsável pela Febre Maculosa Brasileira. No sudeste do país a doença é endêmica e inquéritos sorológicos tem demonstrado presença de anticorpos para antígenos do GFM em cães, reforçando a participação do cão como sentinela. Os principais vetores são carrapatos do gênero Amblyomma, cujos hospedeiros são, muitas vezes, animais de vida silvestre. Assim, objetivou-se avaliar a circulação de rickettsias do GFM no entorno de Unidades de Conservação (UC) no Rio de Janeiro por meio da Imunofluorescência Indireta em cães, além de determinar os fatores associados. Amostras de soro de 155 cães foram testadas, sendo 16,1% dos animais sororreagentes pelo menos a um dos antígenos testados. Houve associação entre a sororreatividade dos cães e o acesso à mata; falta de assistência médico-veterinária; falta de medidas contra carrapatos; e renda familiar do responsável de até dois salários mínimos. Cães com este perfil apresentaram maior chance de serem expostos aos agentes do GFM. De acordo com o modelo de regressão logística, não frequentar áreas de mata foi considerado um fator de proteção para o cão, juntamente com possuir acompanhamento médico-veterinário e receber medidas contra carrapatos. Concluiu-se que patógenos do GFM circulam no entorno das UC estudadas, sendo possível que R. rickettsii e R. parkeri infectem cães, uma vez que os animais demonstraram exposição aos dois agentes. Ressalta-se a participação do veterinário e a adoção de medidas de combate a carrapatos como ferramentas na prevenção da infecção rickettsial.(AU)
Diseases caused by Rickettsiae have wide distribution and are associated with arthropods. Rickettsia rickettsii is the most pathogenic species of the Spotted Fever Group (SFG) and responsible for the Brazilian Spotted Fever. In the southeast the disease is endemic and serological surveys have demonstrated the presence of antibodies to SFG antigens in dogs, reinforcing the participation of the dog as sentinels. The main vectors are Amblyomma ticks, for which hosts are often wildlife animals. The aim of this study was to evaluate the presence of SFG Rickettsiae in the surroundings of Conservation Units (UC) at the state of Rio de Janeiro by Indirect Immunofluorescence Assay in dogs, and determine associated factors. Serum samples of 155 dogs were tested, with 16.1% of the seropositive animals at least to one of the antigens tested. There was an association between seroreactivity dogs and access to rainforest fragments; lack of veterinary care assistance; lack of actions against ticks; and family income up to two minimum salaries. Dogs with this profile had a higher chance of being exposed to SFG Rickettsiae. According to logistic regression, not going to rainforest areas was considered a protective factor for the dog along with the existence of veterinary care assistance and treatment against ticks. It was concluded that the SFG pathogens are present in the surroundings of UC studied, and possibly both R. rickettsii and R. parkeri are infecting dogs, since the animals showed exposure to both agents. We emphasize the participation of the veterinary and the adoption of the tick control measures as tools in preventing rickettsial infection.(AU)
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Animals , Dogs , Rickettsia , Rocky Mountain Spotted Fever/veterinary , Dogs/microbiology , Serologic Tests/veterinary , Odds RatioABSTRACT
The canine monocytic ehrlichiosis, caused by Ehrlichia canis, is endemic in several regions of Brazil. Some serological diagnostic techniques using immunodominant proteins of E. canis as antigens are available, but their specificities and sensitivities are questionable. Based on this, the objective of this study was to test the antigenic potential of the recombinant gp19 protein (rGP19) for subsequent use in diagnostic tests. The rGP19 expressed in the Escherichia coli strain BL21 (DE3) C41 was recognized in the sera from experimentally infected dogs using ELISA and Western blotting. Thus, it was possible to obtain a promising antigen with the ability to differentiate between E. canis-positive and -negative animals, even 1 week after infection.
A erliquiose monocítica canina, causada por Ehrlichia canis, é uma doença endêmica em diversas regiões do Brasil. Algumas técnicas de diagnóstico sorológico, utilizando proteínas imunodominantes de E. canis como antígenos, estão disponíveis, porém suas especificidades e sensibilidades são questionáveis. Com base nesse fato, o objetivo deste trabalho foi testar o potencial antigênico da proteína GP19 recombinante (rGP19) para posterior utilização em testes diagnósticos. A rGP19, expressa em E. coli cepa BL21 (DE3) C41, foi reconhecida por soros de cães experimentalmente infectados pelas técnicas de ELISA e Western blotting. Dessa maneira, conseguiu-se obter um antígeno promissor com a capacidade de diferenciar animais positivos de negativos, até mesmo uma semana após a infecção.
Subject(s)
Animals , Dogs , Antibodies, Bacterial/immunology , Antibodies, Bacterial/blood , Dog Diseases/diagnosis , Dog Diseases/blood , Ehrlichiosis/diagnosis , Ehrlichiosis/blood , Ehrlichiosis/veterinary , Brazil , Recombinant Proteins/immunology , Serologic TestsABSTRACT
Objective Toinvestigatethestatusoftick-borneRickettsiaeinfectionsamongmurine-likeanimalsin differentareasofZhejiangprovince.Methods Liverandspleensamplesofmurine-likeanimalscapturedthroughnight trapping method were collected from Anji,Jinhua and Tiantai County according to their geographic locations and historical detection of Rickettsiae .Nest-PCR tests were used to determine the presence of the 16S rRNA genes of Anaplasma and Ehrlichia ,and the heat shock protein genes (groEL)of Rickettsiae (including typhus and spotted fever group)and Orientiainthesesamples.Results Atotalof851murine-likeanimalsbelongingto14specieswerecaptured.The predominant species were Rattus confucianus (30.32%),Apodemus agrarius (18.80%) and Thallomys paedulcus (1 1.75%)and they were significantly different among three areas (P<0.05 ).48 Rickettsia positive were found in 562 tested samples with the positive rate of 8.54%,among which the percentage of Anaplasma,typhus group Rickettsia, Orientia,Ehrlichia and spotted fever group Rickettsia were 3.38%,1.78%,1.78%,1.07% and 0.53% respectively. The positive rates of Anaplasma in Jindong (4.76%)and Anji (4.27%)were significantly higher than that in Tiantai (P<0.05 )while the spotted fever group Rickettsia were found only in Tiantai County.Moreover,Rattus confucianus-the predominant species of Zhejiang Province-had the highest infection rate of tick-borne Rickettsiae up to 14.97%.Co-infections with several Rickettsiae were existed among the same species.Conclusion Rickettsiae infections exist widely among different areas of Zhejiang province and the positive rates are significantly different among species.
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Spotted fever caused by spotted fever group rickettsiae (SFGR) is found throughout China. During 2007—2008, 28 human SFGR isolates and 34 rat SFGR isolates including 15 isolates from <i>Rattus fulvescens</i>, 5 isolates from <i>R.edwardsi</i>, 7 isolates from <i>Callosciurus erythraeus roberti</i> and 7 isolates from <i>Dremomys rufigenis</i>) were obtained from L929 cell culture. Previous research indicated that the 62 strains of SFGR mentioned above shared not only the same serophenotype but also 100% of identity sequences of 16S rRNA, <i>gltA</i>, <i>ompA</i>, <i>groEL</i> and 17KD, which enabled us to apply multispacer typing (MST) to the 62 SFGR isolates in the study. Six primer pairs, which were used for typing of <i>Rickettsia rickettsii</i> and <i>Rickettsia conorii</i>, were chosen, and the results exhibited greater nucleotide polymorphisms among the 62 isolates tested. A total of 48 distinct genotypes were identified. The dominant genotype, represented by h3 isolates, accounted for 21.7% (13/60) of the isolates tested, and the remaining 47 genotypes were all unique. Phylogenetic analysis showed that all the 48 genotypes could be classified in the same clade, while the genetically related strain, <i>R.heilongjiangensis</i>, was close but not the same as the cluster. We concluded that the genetically diverse of spotted fever group rickettsiae strains are endemic in Chengmai County, Hainan Province, China.
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Spotted fever caused by spotted fever group rickettsiae (SFGR) is found throughout China. During 2007–2008, 28 human SFGR isolates and 34 rat SFGR isolates including 15 isolates from <i>Rattus fulvescens</i>, 5 isolates from <i>R. edwardsi</i>, 7 isolates from <i>Callosciurus erythraeus roberti</i> and 7 isolates from <i>Dremomys rufigenis</i>) were obtained from L929 cell culture. Previous research indicated that the 62 strains of SFGR mentioned above shared not only the same serophenotype but also 100% of identity sequences of 16S rRNA, <i>gltA</i>, <i>ompA</i>, <i>groEL</i> and 17KD, which enabled us to apply multispacer typing (MST) to the 62 SFGR isolates in the study. Six primer pairs, which were used for typing of <i>Rickettsia rickettsii</i> and <i>Rickettsia conorii</i>, were chosen, and the results exhibited greater nucleotide polymorphisms among the 62 isolates tested. A total of 48 distinct genotypes were identified. The dominant genotype, represented by h3 isolates, accounted for 21.7% (13/60) of the isolates tested, and the remaining 47 genotypes were all unique. Phylogenetic analysis showed that all the 48 genotypes could be classified in the same clade, while the genetically related strain, <i>R. heilongjiangensis</i>, was close but not the same as the cluster. We concluded that the genetically diverse of spotted fever group rickettsiae strains are endemic in Chengmai County, Hainan Province, China.
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Objective To monitor the co-infection status of Borrelia burgdorferi sensu lato (R.b.s.1) and spotted fever group Rickettsia (SFGR) in tourist areas of Heilongjiang province.Methods Polymerase chain reaction (PCR) was used to detect the 5S-23S rRNA intergenic spacer of B.b.s.1 and ompA of SFGR in ticks,dynamically collected from tourist areas of Heilongjiang province in 2010.Amplification products from positive ticks were sequenced,and phylogenetic analysis was conducted by Mega 5.0 software package.Results 849 ticks were collected from two tourist points,with the dominant ticks in Tiger Mountain and Jingpo Lake were Ixodes persulcatus and Haemaphysalis concinna.Regarding the Ixodes persulcatus from Tiger Mountain,the infection rates of B.b.s.1 and SFGR were 26.15％ and 10.05％.The infection rate of SFGR was 13.33％ in Haemaphysalis concinna and the B.b.s.1 was tndiscovered in the same ticks from Jingpo Lake.However,the co-infection could only be detected in Ixodes persulcatus of both tourist areas.Surveillance data showed that the major ticks were more likely to be appeared in July at Tiger Mountain and in June at Jingpo Lake.Data from the sequence analysis on B.b.s.1 showed that the B.b.s.1 in tourist areas could be classified into three different genotypes,other than B.garinii and B.afzelii.We first detected B.valaisiana-like group genotype in northeast of China.Results from the sequence analysis of SFGR positive products showed that the two DNA sequences of newly detected agents were completely the same as Rickettsia sp.HL-93 which was detected in Hulin and Rickettsia sp.H820 found in northeast,China.Conclusion The co-infection of B.b.s.1 and SFGR was detected in ticks from the tourist areas of Heilongjiang province,and data from the sequencing of specific fragment showed that various kinds of genotypes existed in this area.However; the rates of co-infectionitis-different according to environment,time and population that contributed to the kinds of and the index of ticks existed in the surveys points,also the infection rate of the ticks was studied.
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Objectives: To report a series of cases of rickettsial infections from central India and to develop a clinical scoring system for its early detection. Design: Retrospective review of children hospitalized during one year period with fever without a source, and presence of one or more of the clinical features suggestive of rickettsial infection. Diagnosis of rickettsial disease was made by classical clinical features and detection of IgM antibody by ELISA. A clinical scoring system was developed to diagnose spotted fever group by using classical clinical and laboratory findings. Results: 161 patients were admitted and met the inclusion criteria, 75 (45.6%) were diagnosed with rickettsial diseases. 52 (69.3%) had spotted fever group and 23 (30.7%) scrub typhus. The mortality rate with rickettsial diseases was 9%. By using proposed clinical scoring system, a score of 14 has sensitivity and specificity of 96.15% and 98.84%, respectively in making a diagnosis of spotted fever group. Conclusion: Rickettsial diseases are common in the central part of India and should be included in the differential diagnosis of patients with fever of undetermined source. The proposed scoring system can be used for early detection, treatment and prevention of mortality and morbidity from spotted fever group.
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To understand the sero-epidemiological features of rickettesiosis of humans and domestic animals in Yunnan province, blood samples from 237 adults in different geographic area, including Xundian country,Yulong country and Simao country and 81 children aged from 4 to 6 years old were collected for serological testing. In addition, 90 blood samples from dogs, goats and ox in each investigated area were also collected. Antibodies against 8 rickettsiae, including R.typhi, R.heilongjiangii or R.sibirica, Orientia tsutsugamushi Karp or Kato, Ehrlichia chaffeensis, Anaplasma phagocytosis, Bartonella henselae, Coxiella burnetii and Hainan spotted fever group of rickettsia were examined by using immunofluorescence assays(IFA).It was found that the sero-epidemiologic rates of R.typhi, B.henselae and C.burnetii (16.46%、6.33% and 9.28%) of adults were higher than those of other rickerrsiae investigated. The positive rates of IgG antibody against R.typhi for children also shared the higher rate (12.35%). Similar sero-epidemiologic features were found for domestic animals. Among the 8 rickettsia tested in this study, the positive rate of IgG antibody against R.typhi appeared to be the highest(61.48%) without significant difference among these investigated sites. From this investigation, it is evident that the rickettsial infection of farm population and domestic animals are common in Yunnan province, and the active surveillance of rickettsiosis and differential diagnosis of unknown febrile patients in clinical practice should be enforced.
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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 of Rickettsiae heilongjiangii, Orientia tsutsugamushi, R. typhi, Anaplasma phagocytos, Ehrlichia chaffeensis, Bartonella, R. hainan and Coxiella burnetii in these samples.Results Six hundred and eighty-three blood samples including 579 from humans and 104 from domestic animals(53 from cattles and 51 from sheep)were collected from the three sites. Antibody positive rates of Orientia tsutsugamushi, R. typhi, Ehrlichia chaffeensis and Coxiella burnetii were significantly different between these sites. IgG from all the 8 pathogens were detected in samples from humans. It was found that the sero-prevalence rates of R. typhi, Bartonella and C. burnetii(20.7%,10.9%, 5.5%)of adults were higher than those of other Rickettsiae under investigation. The seroprevalence of R. typhi increased along with age. IgG from the 7 pathogens were detected in samples from domestic animals except for Anaplasma phagocytos. The sero-prevalence rates of R. typhi, Bartonella and R. hainan(69.2%, 51.0%, 22.1%)of adults were higher than those of other Rickettsiae investigated. Conclusion Tick-borne diseases did spread widely in humans and domestic animals from different rural areas of Zhejiang province. The sero-prevalence rates of R. typhi,B. henselae, R. hainan and C. burnetii were higher than that from other pathogens.
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Objective The present study was conducted to investigate the infection of Lyme disease, Spotted fever, Ehrlichiosis (anaplasmosisin) in wild animals and ticks in the mountain areas of Zhejiang province. Methods Nested polymerase chain reaction was used to amplify specific DNA sequences of Lyme spirochetes, Spotted fever group rickettsiae, Ehrlichia (anaplasma) from samples of mice and ticks. Results 14 positive samples were identified from 121 mice and 105 groups of ticks. Among mice samples, one positive 5S-23S rDNA intergenic spacer of Borreia burgdorferi and two 5' fragments of Ehrlichia (anaplasma) 16S rDNA were obtained. 11 positive results were detected from tick samples including three 5S-23S rDNA intergenic spacer regions of Borreia burgdorferi and eight 5' fragments of Spotted fever group rickettsiae outer member protein A gene. One group of adult ticks, Haemaphysalis longicornis, which had been collected from eastern mountain area were detected to have co-infected with Lyme spirochetes and Spotted fever group rickettsiae. The positive sequences of 5S-23S rDNA intergenic spacer and ompA gene were tested and analyzed as Lyme spirochetes while rickettsia which was closely related to Borrelia valaisiana and R. massilliae. Conclusion This was the first report about co-infection of Lyme spirochetes and Spotted fever group rickettsiae found in the same group of adult Haemaphysalis longicornis. It is very important to strengthen the surveillance program on tick-borne infectious disease and their pathogenic in vectors, wild animals and targeted high risk groups and to differentiate the clinical manifestation and diagnosis to extend the knowledge of tick-borne infectious diseases in Zhejiang.
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Objective To study the infection rate, epidemiological features of Far-East tick-borne spotted fever in the Northeastern area of China and to provide evidence for prevention and control. Methods Nine cities from the three Northeastern provinces were chosen. Human serum, rat, serum, free tick sample as well as blood from suspected patients were determined by indirect immuno-fluoresenee assay. Rickettsiae was identified by guinea pigs plant method. Results The overall rate of infection among human beings was 17.46% ,with R. heilongjiangensis antibody the major one among the nine cities. The annual infection rate was 9.4 %. In a two year period, the rates of being bitten by ticks among forestry workers was 92.8 %, and 33.5 % among soldiers. The antibody positive rate and tick-bite rate were positively correlated. The serum positive rate in rats was 27.3%. 20 strains were isolated from blood which confirmed that 16 cases were related to R. heilongjiangensis and another 16 cases were Far East tick-Dome spotted fever. Clinical features of the patients were also analyzed. Conclusion Nine cities from the east part of the Northeastern areas of China were confirmed of having R. heilongjiangensis infection (3.4%-27.4%). Our results also demonstrated that in those above-mentioned areas,there had been an existing natural foci of Far East tick-borne spotted fever.