scholarly journals Human Spotted Fever Group Rickettsia Infecting Yaks (Bos grunniens) in the Qinghai-Tibetan Plateau Area

Pathogens ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 249
Author(s):  
Yingna Jian ◽  
Jixu Li ◽  
Paul Franck Adjou Moumouni ◽  
Xueyong Zhang ◽  
Maria Agnes Tumwebaze ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Disease Transmission ◽  
Homo Sapiens ◽  
Spotted Fever ◽  
Molecular Characteristics ◽  
Spotted Fever Group ◽  
Human Pathogen ◽  
Bos Grunniens ◽  
Plateau Area ◽  
Sfg Rickettsia

The Qinghai-Tibetan Plateau Area (QTPA) is a plateau with the highest average altitude, located in Northwestern China. There is a risk for interspecies disease transmission, such as spotted fever rickettsioses. However, information on the molecular characteristics of the spotted fever group (SFG) Rickettsia spp. in the area is limited. This study performed screenings, and detected the DNA of human pathogen, SFG Rickettsia spp., with 11.3% (25/222) infection rates in yaks (Bos grunniens). BLASTn analysis revealed that the Rickettsia sequences obtained shared 94.3–100% identity with isolates of Rickettsia spp. from ticks in China. One Rickettsia sequence (MN536161) had 100% nucleotide identity to two R. raoultii isolates from Chinese Homo sapiens, and one isolate from Qinghai Dermacentor silvarum. Meanwhile, another Rickettsia sequence (MN536157) shared 99.1–99.5% identity to one isolate from Dermacentor spp. in China. Furthermore, the phylogenetic analysis of SFG Rickettsia spp. ompA gene revealed that these two sequences obtained from yaks in the present study grouped with the R. slovaca and R. raoultii clades with isolates identified from Dermacentor spp. and Homo sapiens. Our findings showed the first evidence of human pathogen DNA, SFG Rickettsia spp., from animals, in the QTPA.

scholarly journals Development of a Multiplex Loop-Mediated Isothermal Amplification (LAMP) Method for Simultaneous Detection of Spotted Fever Group Rickettsiae and Malaria Parasites by Dipstick DNA Chromatography

Diagnostics ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 897
Author(s):  
Lavel Chinyama Moonga ◽  
Kyoko Hayashida ◽  
Naoko Kawai ◽  
Ryo Nakao ◽  
Chihiro Sugimoto ◽  
...  
Keyword(s):  
Detection System ◽  
Spotted Fever ◽  
Simultaneous Detection ◽  
Febrile Illness ◽  
Isothermal Amplification ◽  
Lamp Method ◽  
Spotted Fever Group ◽  
Loop Mediated Isothermal Amplification ◽  
Rickettsia Monacensis ◽  
Sfg Rickettsia

Spotted fever group (SFG) rickettsiae causes febrile illness in humans worldwide. Since SFG rickettsiosis’s clinical presentation is nonspecific, it is frequently misdiagnosed as other febrile diseases, especially malaria, and complicates proper treatment. Aiming at rapid, simple, and simultaneous detection of SFG Rickettsia spp. and Plasmodium spp., we developed a novel multiple pathogen detection system by combining a loop-mediated isothermal amplification (LAMP) method and dipstick DNA chromatography technology. Two primer sets detecting SFG Rickettsia spp. and Plasmodium spp. were mixed, and amplified products were visualized by hybridizing to dipstick DNA chromatography. The multiplex LAMP with dipstick DNA chromatography distinguished amplified Rickettsia and Plasmodium targeted genes simultaneously. The determined sensitivity using synthetic nucleotides was 1000 copies per reaction for mixed Rickettsia and Plasmodium genes. When genomic DNA from in vitro cultured organisms was used, the sensitivity was 100 and 10 genome equivalents per reaction for Rickettsia monacensis and Plasmodium falciparum, respectively. Although further improvement will be required for more sensitive detection, our developed simultaneous diagnosis technique will contribute to the differential diagnosis of undifferentiated febrile illness caused by either SFG Rickettsia spp. or Plasmodium spp. in resource-limited endemic areas. Importantly, this scheme is potentially versatile for the simultaneous detection of diverse infectious diseases.

scholarly journals The Rickettsia conorii Autotransporter Protein Sca1 Promotes Adherence to Nonphagocytic Mammalian Cells

2010 ◽  
Vol 78 (5) ◽  
pp. 1895-1904 ◽  
Author(s):  
Sean P. Riley ◽  
Kenneth C. Goh ◽  
Timothy M. Hermanas ◽  
Marissa M. Cardwell ◽  
Yvonne G. Y. Chan ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Spotted Fever ◽  
Expression System ◽  
Host Cells ◽  
Rickettsia Conorii ◽  
Spotted Fever Group ◽  
Gram Negative Bacteria ◽  
Heterologous Expression System ◽  
Cell Association ◽  
Sfg Rickettsia

ABSTRACT The pathogenesis of spotted fever group (SFG) Rickettsia species, including R. conorii and R. rickettsii, is acutely dependent on adherence to and invasion of host cells, including cells of the mammalian endothelial system. Bioinformatic analyses of several rickettsia genomes revealed the presence of a cohort of genes designated sca genes that are predicted to encode proteins with homology to autotransporter proteins of Gram-negative bacteria. Previous work demonstrated that three members of this family, rOmpA (Sca0), Sca2, and rOmpB (Sca5) are involved in the interaction with mammalian cells; however, very little was known about the function of other conserved rickettsial Sca proteins. Here we demonstrate that sca1, a gene present in nearly all SFG rickettsia genomes, is actively transcribed and expressed in R. conorii cells. Alignment of Sca1 sequences from geographically diverse SFG Rickettsia species showed that there are high degrees of sequence identity and conservation of these sequences, suggesting that Sca1 may have a conserved function. Using a heterologous expression system, we demonstrated that production of R. conorii Sca1 in the Escherichia coli outer membrane is sufficient to mediate attachment to but not invasion of a panel of cultured mammalian epithelial and endothelial cells. Furthermore, preincubation of a recombinant Sca1 peptide with host cells blocked R. conorii cell association. Together, these results demonstrate that attachment to mammalian cells can be uncoupled from the entry process and that Sca1 is involved in the adherence of R. conorii to host cells.

scholarly journals One Health Approach to Rickettsiosis: A Five-Year Study on Spotted Fever Group Rickettsiae in Ticks Collected from Humans, Animals and Environment

2021 ◽  
Vol 10 (1) ◽  
pp. 35
Author(s):  
Ilaria Pascucci ◽  
Elisa Antognini ◽  
Cristina Canonico ◽  
Marco Giuseppe Montalbano ◽  
Alessandro Necci ◽  
...  
Keyword(s):  
Spotted Fever ◽  
Rhipicephalus Sanguineus ◽  
Geographic Area ◽  
Molecular Diagnostic ◽  
Spotted Fever Group ◽  
Rickettsia Species ◽  
Glta Gene ◽  
Starting Point ◽  
Pcr Products ◽  
Sfg Rickettsia

The spotted fever group of Rickettsiae is a heterogeneous group of Rickettsiae transmitted by ticks, causing similar diseases in humans (spotted fever). Until recently, it was supposed that a single pathogenic tick-borne SFG Rickettsia circulated in each different geographic area and that R. conorii subsp. conorii was the SFG Rickettsiae circulating in Italy, but in the last decade, thanks to molecular diagnostic, several different Rickettsia species, previously not considered pathogenic for decades, have been isolated from ticks and definitively associated to human disease, also in Italy. The present survey was carried out with the aim of investigating the presence of different SFG Rickettsia species in a geographic area where no information was available. Ticks collected from animals submitted to necropsy, removed from humans in local hospitals and collected from the environment were identified and tested by PCR for Rickettsia spp. based on the gltA gene, and positive PCR products were sequenced. A total of 3286 ticks were collected. Fifteen tick species were recognized, the most represented (79.52%) species in the collection was Ixodes ricinus, followed by Rhipicephalus sanguineus (9.13%). The overall prevalence of Rickettsia infection was 7.58%. Eight species of Rickettsia were identified, the most frequent was R. monacensis (56%), followed by R. helvetica (25.50%). Noteworthy, is the detection in the present study of Rrhipicephali, detected only twice in Italy. These are the first data available on SFG Rickettsiae circulation in the study area and they can be considered as starting point to assess the possible risk for humans.

scholarly journals Algorithms of Rickettsiae’s Detection and Laboratory Diagnosis of Rickettsioses of Spotted Fever Group in Russia

2015 ◽  
Vol 14 (2) ◽  
pp. 6-9
Author(s):  
N. V. Rudakov ◽  
I. E. Samoylenko ◽  
L. V. Kumpan
Keyword(s):  
Restriction Analysis ◽  
Spotted Fever ◽  
Laboratory Diagnosis ◽  
Laboratory Diagnostics ◽  
Spotted Fever Group ◽  
Detection And Identification ◽  
Manufactured Products ◽  
Pcr Products ◽  
Biological Methods ◽  
Sfg Rickettsia

An analysis of modern trends of Rickettsiae’s detection and laboratory diagnostics for spotted fever group rickettsioses is present. Due to the sharp decline in the range of manufactured products and increase the spectrum of rickettsial species identified in Russia, new approaches required to laboratory verification of diagnoses. IFA and ELISA with antigens of relevant species of Rickettsia can be recommended to detect antibodies to the SFG rickettsiae. PCR-restriction analysis and sequencing of PCR products most appropriate for the detection and identification of SFG Rickettsia, biological methods are necessary for studying of pathogenic species of Rickettsia.

RETROSPECTIVE SEROLOGICAL DIAGNOSTICS OF SPOTTED FEVER GROUP RIKKETSIOSES IN HIGH RISK AREAS OF RICKETTSIA CONORII SUBSP. CASPIA INFECTION

2019 ◽  
Vol 64 (6) ◽  
pp. 354-359 ◽  
Author(s):  
T. A. Chekanova ◽  
S. Zh. Netalieva ◽  
S. N. Shpynov ◽  
M. A. Babaeva ◽  
A. V. Kostarnoy
Keyword(s):  
High Risk ◽  
Spotted Fever ◽  
Activity Period ◽  
Rickettsia Conorii ◽  
Spotted Fever Group ◽  
Adenovirus Infection ◽  
Risk Areas ◽  
Acute Respiratory Viral Infection ◽  
Serological Diagnostics ◽  
Sfg Rickettsia

723 blood sera from 537 patients of Regional Infectious Clinical Hospital, Astrakhan were obtained during high activity period of Rhipicephalus ticks (May-September 2015) and retrospectively studied for IgG/IgM to antigen of spotted fever group (SFG) Rickettsia. IgG and/or IgM to Rickettsia conorii were detected in 145 sera from 130 patients, and antibodies to R. sibirica (group-specific) were detected in 143 sera from 145. Antibodies to R. conorii were detected for 71,4% patients with Astrakhan spotted fever (ASF), for 28,4% patients with acute respiratory viral infection, for 19,1% patients with infection of unspecified etiology and for 40% patients having symptoms of a adenovirus infection. Acute rickettsiosis, provably ASF, is serologically validated for 71 patients. Dynamic of IgM/IgG to R. conorii in sera of patients having different preliminary diagnoses is discussed. IgM to R. conorii in sera of patients having adenovirus infection symptoms were detected at a later time as compared with others. For regions of high risk of R. conorii subsp. caspia infection the differentiation of diagnostic and anamnestic specific antibodies is very important. The absence of serological and molecular biological markers in third of patients with ASF symptoms is necessary to study. Preparations and algorithms for diagnosis of SFG rickettsioses are needed to improve.

scholarly journals Antigenic Classification of Rickettsia felis by Using Monoclonal and Polyclonal Antibodies

2003 ◽  
Vol 10 (2) ◽  
pp. 221-228 ◽  
Author(s):  
Rong Fang ◽  
Didier Raoult
Keyword(s):  
Monoclonal Antibodies ◽  
Polyclonal Antibodies ◽  
Spotted Fever ◽  
Spotted Fever Group ◽  
Neighbor Joining ◽  
Rickettsia Felis ◽  
Polyclonal Antisera ◽  
Antigenic Profile ◽  
Sfg Rickettsia

ABSTRACT Rickettsia felis is a flea-transmitted rickettsia. There is a discrepancy between its reported phylogenic and phenotypic identifications. Following the first report of R. felis, it was considered by tests with serologic reagents to be closely related to another recognized flea-transmitted rickettia, R. typhi. Subsequently, it appeared to be more closely related to spotted fever group (SFG) rickettsiae by genetic analysis. In the present work, R. felis was studied by microimmunofluorescence (MIF) serologic typing and with monoclonal antibodies (MAbs). Mouse polyclonal antisera to R. felis cross-reacted only with SFG rickettsiae. A neighbor-joining analysis based on MIF indicated that R. felis is actually related to SFG rickettsiae antigenically, clustering with R. australis, R. akari, and R. montanensis. A panel of 21 MAbs was raised against a 120-kDa protein antigen or a 17-kDa polypeptide of R. felis. They cross-reacted with most members of the SFG rickettsiae but not with R. prowazekii, R. typhi, or R. canadensis of the typhus group (TG) rickettsiae. Sixty-four MAbs previously generated to seven other ricketttsial species were tested with R. felis. Three MAbs reacted with the 120-kDa antigen and were generated by R. africae, R. conorii, and R. akari, respectively. They exhibited cross-reactivities with R. felis. All our data show that R. felis harbors the antigenic profile of an SFG rickettsia.

scholarly journals Serological Evidence of Anaplasma phagocytophilum and Spotted Fever Group Rickettsia spp. Exposure in Horses from Central Italy

Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 88 ◽  
Author(s):  
Valentina Virginia Ebani
Keyword(s):  
Anaplasma Phagocytophilum ◽  
Spotted Fever ◽  
Central Italy ◽  
Geographic Area ◽  
Spotted Fever Group ◽  
Serum Samples ◽  
Health Concept ◽  
Spotted Fever Group Rickettsia ◽  
The One ◽  
Sfg Rickettsia

Anaplasma phagocytophilum and Rickettsia spp. are tick-borne bacteria of veterinary and human concern. In view of the One-Health concept, the present study wanted to evaluate the spreading of these pathogens in horses living in central Italy. In particular, the aim of the investigation was to verify the exposure to A. phagocytophilum in order to update the prevalence of this pathogen in the equine population from this area, and to spotted fever group (SFG) Rickettsia spp. to evaluate a possible role of horses in the epidemiology of rickettsiosis. Indirect immunofluorescent assay was carried out to detect antibodies against A. phagocytophilum and SFG (spotted fever group) Rickettsia spp. in blood serum samples collected from 479 grazing horses living in central Italy during the period from 2013 to 2018. One hundred and nine (22.75%) horses were positive for A. phagocytophilum, 72 (15.03%) for SFG Rickettsia spp., and 19 (3.96%) for both antigens. The obtained results confirm the occurrence of A. phagocytophilum in equine populations, and also suggest the involvement of horses in the epidemiology of SFG rickettsiosis. In both cases, in view of the zoonotic aspect of these pathogens and the frequent contact between horses and humans, the monitoring of equine populations could be useful for indication about the spreading of the tick-borne pathogens in a certain geographic area.

scholarly journals Identification and Characterization of “Candidatus Rickettsia Thierseensis”, a Novel Spotted Fever Group Rickettsia Species Detected in Austria

2020 ◽  
Vol 8 (11) ◽  
pp. 1670
Author(s):  
Anna-Margarita Schötta ◽  
Michiel Wijnveld ◽  
Dieter Höss ◽  
Gerold Stanek ◽  
Hannes Stockinger ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Spotted Fever ◽  
Intergenic Spacer ◽  
Borrelia Burgdorferi Sensu Lato ◽  
Species Discrimination ◽  
Spotted Fever Group ◽  
Pathogenic Potential ◽  
Rickettsia Species ◽  
Intergenic Spacer Region ◽  
Sfg Rickettsia

Rickettsia spp. are the second most common pathogens detected in Ixodes ricinus ticks in Austria after Borrelia burgdorferi sensu lato. Species belonging to the spotted fever group (SFG) are the causative agents for tick-borne rickettsiosis across the world. So far, only four SFG Rickettsia spp. were detected in Austria, namely R. helvetica, R. raoultii, R. monacensis and R. slovaca. Here, we describe the identification of a new SFG Rickettsia species detected in an I. ricinus tick. Sequencing of various rickettsial genes revealed a nucleotide sequence similarity of 99.6%, 98.5%, 97.3% and 98.5% to the gltA, ompA, ompB, and sca4 genes, respectively, of known and validated species. Additionally, sequencing of the htrA gene and 23S-5S intergenic spacer region also only showed 99.6% and 99.2%, respectively, similarity to known species. Therefore, and in accordance with current criteria for Rickettsia species discrimination, we hereby describe a new species of the SFG with putative pathogenic potential. We propose the name “Candidatus Rickettsia thierseensis” based on the village Thiersee in the Austrian province of Tyrol, where the carrying tick was found.

Sign in / Sign up

Export Citation Format

Share Document