scholarly journals Identification and Genetic Diversity Analysis of Rickettsia in Dermacentor Nuttalli Within Inner Mongolia, China

2021 ◽  
Author(s):  
Zheng Gui ◽  
Hao Cai ◽  
Dong-Dong Qi ◽  
Shun Zhang ◽  
Shao-Yin Fu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Inner Mongolia ◽  
Spotted Fever ◽  
Effective Control ◽  
Spotted Fever Group ◽  
Ompa Gene ◽  
Rickettsia Raoultii ◽  
Glta Gene ◽  
Rickettsia Sibirica

Abstract Background The pathogen genus Rickettsia contains the linages spotted fever group, typhus group, transitional group, and the ancestral group, of which the spotted fever group Rickettsia (SFGR) is transmitted by ticks. Dermacentor nuttalli is considered the main vector carrying SFGR. Studying the genetic diversity and population structure of Rickettsia is essential for developing effective control strategies and predicting evolutionary trends of the pathogens. Methods We collected 408 Dermacentor nuttalli in the Inner Mongolia Autonomous region in 2019, detected Rickettsia infection, and characterized the haplotypes. The extracted Rickettsia DNA of the gltA and ompA genes were amplified and sequenced. Result In this study, 10 haplotypes of the gltA gene and 22 haplotypes of the ompA gene were obtained. In the two resulting phylogenetic trees, the haplotypes G1-G7 and G9 of the gltA gene clustered with Rickettsia raoultii, while G8 and G10 clustered with Rickettsia sibirica. Haplotypes O1-O15, O18 and O20-O22 of the ompA gene clustered with Rickettsia raoultii, while O16 and O19 clustered with Rickettsia sibirica. The average haplotype diversity was 0.3 for gltA and 0.7 for ompA, while the average nucleotide diversity was greater than 0.05. Neutrality tests were insignificant for Tajima’s D results and Fu’s Fs results. The fixation index values (FST) showed that the degree of genetic differentiation between most sampled populations was small (FST<0.05), while others were medium (FST>0.05) and large (FST>0.15). Analysis of molecular variance (AMOVA) revealed that the variation within populations was greater than that between populations. The mismatch analysis of Rickettsia showed double peaks. Conclusion We found two genotypes of Rickettsia: Rickettsia raoultii and Rickettsia sibirica. The high genetic diversity of Rickettsia allows for easy adaption to different environments; furthermore, genetic differentiation between populations is small and Rickettsia populations do not show a pedigree geographical structure. The high rates of retention and infestation of Rickettsia in Dermacentor nuttalli together with the animal husbandry exchange in China gradually lead to the genetic characteristics of Rickettsia harmonizing across various regions. Overall, the significant genetic diversity and geographic structure of Rickettsia in Dermacentor nuttalli are critical for SFGR control.

scholarly journals Molecular surveillance of spotted fever group rickettsioses in wildlife and detection of Rickettsia sibirica in a Topi (Damaliscus lunatus ssp. jimela) in Kenya

2017 ◽  
Vol 84 (1) ◽  
Author(s):  
David Ndeereh ◽  
Andrew Thaiyah ◽  
Gerald Muchemi ◽  
Antoinette A. Miyunga
Keyword(s):  
Citrate Synthase ◽  
Spotted Fever ◽  
Intergenic Spacer ◽  
Sub Saharan Africa ◽  
Spotted Fever Group ◽  
Wild Animals ◽  
Rickettsia Species ◽  
Glta Gene ◽  
Sub Saharan ◽  
Rickettsia Sibirica

Spotted fever group rickettsioses are a group of tick-borne zoonotic diseases caused by intracellular bacteria of the genus Rickettsia. The diseases are widely reported amongst international travellers returning from most sub-Saharan Africa with fever, yet their importance in local populations largely remains unknown. Although this has started to change and recently there have been increasing reports of the diseases in livestock, ticks and humans in Kenya, they have not been investigated in wildlife. We examined the presence, prevalence and species of Rickettsia present in wildlife in two regions of Kenya with a unique human–wildlife–livestock interface. For this purpose, 79 wild animals in Laikipia County and 73 in Maasai Mara National Reserve were sampled. DNA extracted from blood was tested using the polymerase chain reaction (PCR) to amplify the intergenic spacer rpmE-tRNAfMet and the citrate synthase-encoding gene gltA. Rickettsial DNA was detected in 2 of the 79 (2.5%) animals in Laikipia and 4 of the 73 (5.5%) in Maasai Mara. The PCR-positive amplicons of the gltA gene were sequenced to determine the detected Rickettsia species. This revealed Rickettsia sibirica in a Topi (Damaliscus lunatus ssp. jimela). This is the first report of spotted fever group rickettsioses in wildlife and the first to report R. sibirica in Kenya. The finding demonstrates the potential role of wild animals in the circulation of the diseases.

scholarly journals Rickettsia sibirica mongolitimonae infection, Sri Lanka

2017 ◽  
Vol 11 (08) ◽  
pp. 668-671
Author(s):  
Charlotte Cordier ◽  
Pierre Tattevin ◽  
Caroline Leyer ◽  
Marine Cailleaux ◽  
Didier Raoult ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Skin Biopsy ◽  
Spotted Fever ◽  
Pcr Amplification ◽  
Rickettsia Conorii ◽  
Spotted Fever Group ◽  
Axillary Lymph ◽  
Ompa Gene ◽  
Rickettsia Felis ◽  
Rickettsia Sibirica

Introduction. Rickettsia sibirica mongolitimonae was recently reported as a common rickettsiosis in France. Current serological evidence suggests the presence of scrub typhus and spotted fever group rickettsiosis in Sri Lanka. We detected a human case of R. sibirica mongolitimonae in Sri Lanka. Methodology. A skin biopsy of the eschar was tested for the presence of Rickettsia spp. using qPCR assay targeting a 109-bp fragment of a hypothetical protein and by PCR amplification and sequencing targeting the ompA gene. Results. A 30-year-old woman who had just returned from travel to a jungle in Sri Lanka was evaluated as an outpatient for fever. Examination revealed an enlarged axillary lymph node, a maculopapular rash and an eschar at her left flank and a skin biopsy of the eschar was performed. The skin biopsy was positive for the presence of Rickettsia spp. by qPCR and PCR amplification and sequencing targeting the ompA gene revealed R. sibirica mongolitimonae. Immunofluorescence assay on an acute serum sample for spotted fever group rickettsial antigens (Rickettsia conorii conorii, R. sibirica mongolitimonae, Rickettsia felis) and typhus group rickettsiae (Rickettsia typhi) was negative. The patient was treated by oral doxycycline (200 mg/day) for one week. Conclusions. R. sibirica mongolitimonae should be considered in the differential diagnosis of patients with suspected rickettsiosis in, or returning from, Sri Lanka.

scholarly journals Evidence for a high prevalence of spotted fever group rickettsial infections in diverse ecologic zones of Inner Mongolia

1995 ◽  
Vol 115 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Qing-Huai Liu ◽  
Guo-Ying Chen ◽  
Yan Jin ◽  
Meng Te ◽  
Li-Chun Niu ◽  
...  
Keyword(s):  
Inner Mongolia ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Spotted Fever ◽  
Spotted Fever Group ◽  
Wild Rodents ◽  
Vegetation Zones ◽  
Rickettsial Infections ◽  
High Prevalence ◽  
Rickettsia Sibirica

SummaryA 3-year study of spotted fever group rickettsial ecology in Inner Mongolia revealed that nearly half of the human population tested had antibodies toRickettsia sibiricadetected by complement fixation test. Infected persons, ticks and a high proportion of seropositive livestock and wild rodents were found in all five vegetation zones (desert, steppe, forest, forest-grassland and grassland).

scholarly journals Spotted Fever Group Rickettsiae in Inner Mongolia, China, 2015–2016

2018 ◽  
Vol 24 (11) ◽  
pp. 2105-2107 ◽  
Author(s):  
Xuhong Yin ◽  
Shengchun Guo ◽  
Chunlian Ding ◽  
Minzhi Cao ◽  
Hiroki Kawabata ◽  
...  
Keyword(s):  
Inner Mongolia ◽  
Spotted Fever ◽  
Spotted Fever Group ◽  
Spotted Fever Group Rickettsiae

scholarly journals Analysis of genetic diversity in Prunus sibirica L. in inner Mongolia using SCoT molecular markers

2022 ◽  
Author(s):  
Ha Buer ◽  
Sa Rula ◽  
Zi Yuan Wang ◽  
Shu Fang ◽  
Yu´e Bai
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Genetic Differentiation ◽  
Inner Mongolia ◽  
Start Codon ◽  
Group Method ◽  
Pair Group ◽  
Protection And Utilization ◽  
Minimum Number ◽  
Polymorphic Bands

AbstractPopulation genetic diversity contributes to the protection and utilization of germplasm resources, especially via genetic breeding. In the present study, start codon targeted polymorphism (SCoT) molecular markers were used to study the genetic diversity of 278 individuals from 10 Prunus sibirica L. populations in Inner Mongolia. A total of 289 polymorphic bands were amplified with 23 SCoT primers, showing a polymorphism percentage of 98.87% and an average of 12.6 polymorphic bands per primer. The SCoT21, SCoT32, and SCoT53 primers amplified up to 17 bands, and the polymorphism percentage was 100%. The minimum number of bands amplified by SCoT25 was 9, and the polymorphism percentage was 90%. Therefore, SCoT molecular markers were shown to be highly polymorphic and suitable for genetic diversity studies of P. sibirica in Inner Mongolia. The analysis of molecular variance showed that 39% of the observed genetic differentiation occurred among populations and 61% occurred within populations, indicating that the genetic differentiation within populations was greater than that among populations. The results of the unweighted pair-group method with an arithmetic cluster analysis, principal coordinate analysis and STRUCTURE analysis were basically the same and divided the 278 individuals from the 10 populations into 2 groups. The results indicated that the efficient SCoT molecular marker-based genetic diversity analysis of P. sibirica in Inner Mongolia can provide a reference for P. sibirica variety breeding and resource development.

scholarly journals Taxonomic Relationships among Spotted Fever Group Rickettsiae as Revealed by Antigenic Analysis with Monoclonal Antibodies

1998 ◽  
Vol 36 (4) ◽  
pp. 887-896 ◽  
Author(s):  
Wenbin Xu ◽  
Didier Raoult
Keyword(s):  
Monoclonal Antibodies ◽  
Phylogenetic Analyses ◽  
Spotted Fever ◽  
Rickettsia Conorii ◽  
Spotted Fever Group ◽  
Antigenic Analysis ◽  
Taxonomic Relationships ◽  
Rickettsia Africae ◽  
Rickettsia Slovaca ◽  
Rickettsia Sibirica

The spotted fever group (SFG) is made up of more than 20 different rickettsial species and strains. Study of the taxonomic relationships among the group has been attempted by phenotypic, genotypic, and phylogenetic analyses. In this study, we determined taxonomic relationships among the SFG rickettsiae by comparative analysis of immunogenic epitopes reactive against a panel of monoclonal antibodies. A total of 98 monoclonal antibodies, which were directed against epitopes on the major immunodominant proteins or on the lipopolysaccharide-like antigens of strains of Rickettsia africae, Rickettsia conorii, Rickettsia massiliae, Rickettsia akari, Rickettsia sibirica, and Rickettsia slovaca, were used in the study. The distribution and expression of the epitopes among 29 SFG rickettsiae and Rickettsia bellii were assessed by determination of reaction titers in a microimmunofluorescence assay. The results were scored as numerical taxonomic data, and cluster analysis was used to construct a dendrogram. The architecture of this dendrogram was consistent with previous taxonomic studies, and the implications of this and other findings are discussed.

scholarly journals Rickettsialpox — a rare but not extinct disease: review of the literature and new directions

2020 ◽  
Vol 10 (3) ◽  
pp. 477-485
Author(s):  
M. E. Eremeeva ◽  
K. Muniz-Rodriguez
Keyword(s):  
Genetic Diversity ◽  
New York ◽  
Spotted Fever ◽  
Research Priorities ◽  
Etiologic Agent ◽  
Spotted Fever Group ◽  
Public Health Importance ◽  
Sexually Transmitted ◽  
Worldwide Distribution ◽  
Clinical Triad

Rickettsialpox is an urban zoonosis caused by Rickettsia akari. To date R. akari is the only well-characterized mite-borne member of the spotted fever group. It is transmitted by the mouse mite, Liponyssoides sanguineus, commonly found on peridomestic rodents. While the disease was first discovered in New York City in 1946, a few years later a similar outbreak occurred in the Ukraine SSR. Numerous serosurveys and diagnosis of sporadic cases of rickettsialpox suggest its global distribution; however, the actual contemporary geography of rickettsialpox and its incidence are unknown. Rickettsialpox is characterized by the classic clinical triad found in rickettsioses of a black eschar, high fever, and rash but the latter is atypical as it is papulovesicular. Dermatological manifestations and the progression of rickettsialpox may mimic other infectious and noninfectious syndromes, including sexually transmitted diseases. The purpose of this review is to increase awareness of this unique disease through reanalysis of classic and contemporary clinical descriptions of rickettsialpox, evaluation of its worldwide distribution, and updates on the public health importance of the disease as well as the ecology and vector associations of R. akari. Our review data suggests that only limited genetic diversity exists among the available isolates of R. akari associated with previous outbreaks; additional effort is still required to define specific genetic markers permitting direct surveillance, accurate and reliable diagnosis, tracking and studying of the vector and host associations of contemporary isolates. The potential of R. akari to cross into other vector species emphasizes the necessity for detection of outbreaks of the disease in new regions of the world and in novel ecological settings. We describe existing gaps and limitations in our current understanding of the pathogenesis of rickettsialpox, the epidemiology of this disease and the genetic diversity of R. akari. We propose research priorities for what is needed to improve our understanding of this neglected rickettsial disease and its etiologic agent.

scholarly journals Genetic diversity analysis of Dermacentor nuttalli within Inner Mongolia, China

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Zheng Gui ◽  
Lin Wu ◽  
Hao Cai ◽  
Lan Mu ◽  
Jing-Feng Yu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
16S Rrna ◽  
Genetic Differentiation ◽  
Inner Mongolia ◽  
Haplotype Diversity ◽  
Fixation Index ◽  
Rrna Gene ◽  
Human Beings ◽  
Autonomous Region ◽  
Inner Mongolia Autonomous Region

Abstract Background Ticks (Arthropoda, Ixodida), after mosquitoes, are the second most prevalent vector of infectious diseases. They are responsible for spreading a multitude of pathogens and threatening the health and welfare of animals and human beings. However, given the history of tick-borne pathogen infections in the Inner Mongolia Autonomous Region of China, surprisingly, neither the genetic diversity nor the spatial distribution of haplotypes within ticks has been studied. Methods We characterized the haplotype distribution of Dermacentor nuttalli in four main pastoral areas of the Inner Mongolia Autonomous Region, by sampling 109 individuals (recovered from sheep) in April–August 2019. The 16S rRNA gene, cytochrome c oxidase subunit I (COI), and the internal transcribed spacer 2 region (ITS2) were amplified and sequenced from extracted DNA. Results Twenty-six haplotypes were identified using 16S rRNA sequences, 57 haplotypes were identified with COI sequences, and 75 haplotypes were identified with ITS2 sequences. Among the three genes, total haplotype diversity was greater than 0.7, while total nucleotide diversity was greater than 0.06. Neutrality tests revealed a significantly negative Tajima’s D result, while Fu's Fs was not significantly positive. Fixation index values (FST) indicated that the degree of genetic differentiation among some sampled populations was small, while for others it was moderate. Analysis of molecular variance (AMOVA) revealed that the variation within populations was greater than that among populations. The mismatch analysis of D. nuttalli exhibited double peaks. Conclusion The genetic diversity of D. nuttalli populations in our region can likely adapt to different geographical environments, thereby leading to genetic diversity, and creating genetic differentiation among different populations. However, genetic differentiation is cryptic and does not form a pedigree geographical structure.

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.

First Molecular Detection of Human Pathogen Rickettsia Raoultii in Ticks from Republic of Korea

2020 ◽  
Author(s):  
Misbah Tariq ◽  
Jun-Won Seo ◽  
Da Young Kim ◽  
Na Ra Yun ◽  
You Mi Lee ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Citrate Synthase ◽  
Phylogenetic Analyses ◽  
Spotted Fever ◽  
Republic Of Korea ◽  
Spotted Fever Group ◽  
Sequencing Data ◽  
Chain Reactions ◽  
Rickettsia Raoultii ◽  
Tick Vectors

Abstract Background: Rickettsial diseases, associated with the spotted fever group (SFG), constitute a growing number of newly identified rickettsia pathogens and their tick vectors, in various parts of the world. At least 15 distinct tick species owing to six genera have shown the presence of Rickettsia raoultii. Here, we report the detection of R. raoultii in ticks from the Republic of Korea (ROK).Methods: A total of 35 ticks, collected from patients of tick bites in Gwangju Metropolitan City, Jeollanam Province, ROK. The ticks were were identified through their molecular, morphological, and taxonomic characteristics. All samples were screened by nested polymerase chain reactions of their outer membrane protein (ompA) and citrate synthase (gltA) genes. The amplified products were sequenced and their phylogenetic analyses were carried out.Results: Sequencing data showed that the DNA sequences of R. raoultii found in the three H. longicornis ticks. All 3 tick samples were 99.4-100% analogous to the previously reported partial sequences of ompA of R. raoultii strains CP019435 and MF002523, forming a single clade with the reference strains.Conclusions: Present study provides the first description and molecular identification of R. raoultii detected in H. longicornis ticks in ROK. This observation extends the geographical distribution of R. raoultii. Screening of human samples for this pathogen will provide information about the prevalence of rickettsial infection in this region.

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