scholarly journals Zoonotic Rickettsia Species in Small Ruminant Ticks From Tunisia

2021 ◽  
Vol 8 ◽  
Author(s):  
Hanène Belkahia ◽  
Rachid Selmi ◽  
Sayed Zamiti ◽  
Monia Daaloul-Jedidi ◽  
Lilia Messadi ◽  
...  
Keyword(s):  
Small Ruminant ◽  
Citrate Synthase ◽  
Spotted Fever ◽  
Protein A ◽  
Rhipicephalus Sanguineus ◽  
Spotted Fever Group ◽  
Rickettsia Species ◽  
Rickettsia Monacensis ◽  
Significant Public Health ◽  
Pcr Targeting

Tick-borne rickettsioses present a significant public health threat among emerging tick-borne diseases. In Tunisia, little is known about tick-borne Rickettsia pathogens. Therefore, the aim of this study was to investigate the presence of Rickettsia species in small ruminant ticks from Tunisia. Adult ticks (n = 694) were collected from goats and sheep in northern Tunisia. Obtained ticks were identified as Rhipicephalus turanicus (n = 434) and Rhipicephalus sanguineus sensu lato (n = 260). Selected ticks (n = 666) were screened for the presence of Rickettsia spp. by PCR targeting a partial sequence of the ompB gene followed by sequence analysis. Rickettsial DNA was detected in 122 (18.3%) tested tick samples. The infection rates in Rh. turanicus and Rh. sanguineus s.l. ticks were 23.4 and 9.5%, respectively. The overall prevalence of rickettsial DNA was markedly higher in ticks collected from goats (23.2%) compared to those infesting sheep (7.9%). The detection of rickettsial DNA was significantly higher in ticks from the governorate of Beja (39.0%) than those from the governorate of Bizerte (13.9%). Two additional genes, the outer membrane protein A gene (ompA) and the citrate synthase gene (gltA), were also targeted for further characterization of the detected Rickettsia species. Genotyping and phylogenetic analysis based on partial sequences (n = 106) of the three different genes revealed that positive ticks are infected with different isolates of two Spotted Fever Group (SFG) Rickettsia, namely, Rickettsia massiliae and Rickettsia monacensis, closely related to those infecting camels and associated ticks from Tunisia, and humans and small ruminant ticks from neighboring countries like Italy, France, and Spain.

scholarly journals Study of infection by Rickettsiae of the spotted fever group in humans and ticks in an urban park located in the City of Londrina, State of Paraná, Brazil

2011 ◽  
Vol 44 (3) ◽  
pp. 313-317 ◽  
Author(s):  
Roberta Santos Toledo ◽  
Katia Tamekuni ◽  
Mauro de Freitas Silva Filho ◽  
Valeska Bender Haydu ◽  
Richard Campos Pacheco ◽  
...  
Keyword(s):  
Citrate Synthase ◽  
Spotted Fever ◽  
Immunofluorescence Assay ◽  
Etiologic Agent ◽  
Spotted Fever Group ◽  
Rickettsia Species ◽  
Rickettsia Rickettsii ◽  
Serological Studies ◽  
Human Sera ◽  
Brazilian Spotted Fever

INTRODUCTION: Spotted fevers are emerging zoonoses caused by Rickettsia species in the spotted fever group (SFG). Rickettsia rickettsii is the main etiologic agent of Brazilian spotted fever (BSF) and it is transmitted by Amblyomma spp. ticks. METHODS: The study aimed to investigate SFG rickettsiae in the Arthur Thomas Municipal Park in Londrina, PR, by collecting free-living ticks and ticks from capybaras and blood samples from personnel working in these areas. Samples from A. dubitatum and A. cajennense were submitted for PCR in pools to analyze the Rickettsia spp. gltA (citrate synthase gene). RESULTS: All the pools analyzed were negative. Human sera were tested by indirect immunofluorescence assay with R. rickettsii and R. parkeri as antigens. Among the 34 sera analyzed, seven (20.6%) were reactive for R. rickettsii: four of these had endpoint titers equal to 64, 2 titers were 128 and 1 titer was 256. None of the samples were reactive for R. parkeri. An epidemiological questionnaire was applied to the park staff, but no statistically significant associations were identified. CONCLUSIONS: The serological studies suggest the presence of Rickettsiae related to SFG that could be infecting the human population studied; however, analysis of the ticks collected was unable to determine which species may be involved in transmission to humans.

scholarly journals Rickettsia monacensis sp. nov., a Spotted Fever Group Rickettsia, from Ticks (Ixodes ricinus) Collected in a European City Park

2002 ◽  
Vol 68 (9) ◽  
pp. 4559-4566 ◽  
Author(s):  
Jason A. Simser ◽  
Ann T. Palmer ◽  
Volker Fingerle ◽  
Bettina Wilske ◽  
Timothy J. Kurtti ◽  
...  
Keyword(s):  
Cell Lines ◽  
Ixodes Ricinus ◽  
Mammalian Cells ◽  
Citrate Synthase ◽  
Spotted Fever ◽  
Spotted Fever Group ◽  
Mammalian Cell Lines ◽  
Isolation And Characterization ◽  
Rickettsia Monacensis ◽  
City Park

ABSTRACT We describe the isolation and characterization of Rickettsia monacensis sp. nov. (type strain, IrR/MunichT) from an Ixodes ricinus tick collected in a city park, the English Garden in Munich, Germany. Rickettsiae were propagated in vitro with Ixodes scapularis cell line ISE6. BLAST analysis of the 16S rRNA, the citrate synthase, and the partial 190-kDa rickettsial outer membrane protein A (rOmpA) gene sequences demonstrated that the isolate was a spotted fever group (SFG) rickettsia closely related to several yet-to-be-cultivated rickettsiae associated with I. ricinus. Phylogenetic analysis of partial rompA sequences demonstrated that the isolate was genotypically different from other validated species of SFG rickettsiae. R. monacensis also replicated in cell lines derived from the ticks I. ricinus (IRE11) and Dermacentor andersoni (DAE100) and in the mammalian cell lines L-929 and Vero, causing cell lysis. Transmission electron microscopy of infected ISE6 and Vero cells showed rickettsiae within the cytoplasm, pseudopodia, nuclei, and vacuoles. Hamsters inoculated with R. monacensis had immunoglobulin G antibody titers as high as 1:16,384, as determined by indirect immunofluorescence assay. Western blot analyses demonstrated that the hamster sera cross-reacted with peptides from other phylogenetically distinct rickettsiae, including rOmpA. R. monacensis induced actin tails in both tick and mammalian cells similar to those reported for R. rickettsii. R. monacensis joins a growing list of SFG rickettsiae that colonize ticks but whose infectivity and pathogenicity for vertebrates are unknown.

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 Rickettsia felis from Cat Fleas: Isolation and Culture in a Tick-Derived Cell Line

2006 ◽  
Vol 72 (8) ◽  
pp. 5589-5595 ◽  
Author(s):  
Walairat Pornwiroon ◽  
Susan S. Pourciau ◽  
Lane D. Foil ◽  
Kevin R. Macaluso
Keyword(s):  
Cell Line ◽  
Citrate Synthase ◽  
Ixodes Scapularis ◽  
Spotted Fever ◽  
Protein A ◽  
Etiologic Agent ◽  
Host Cells ◽  
Spotted Fever Group ◽  
Rickettsia Felis ◽  
Cat Fleas

ABSTRACT Rickettsia felis, the etiologic agent of spotted fever, is maintained in cat fleas by vertical transmission and resembles other tick-borne spotted fever group rickettsiae. In the present study, we utilized an Ixodes scapularis-derived tick cell line, ISE6, to achieve isolation and propagation of R. felis. A cytopathic effect of increased vacuolization was commonly observed in R. felis-infected cells, while lysis of host cells was not evident despite large numbers of rickettsiae. Electron microscopy identified rickettsia-like organisms in ISE6 cells, and sequence analyses of portions of the citrate synthase (gltA), 16S rRNA, Rickettsia genus-specific 17-kDa antigen, and spotted fever group-specific outer membrane protein A (ompA) genes and, notably, R. felis conjugative plasmids indicate that this cultivatable strain (LSU) was R. felis. Establishment of R. felis (LSU) in a tick-derived cell line provides an alternative and promising system for the expansion of studies investigating the interactions between R. felis and arthropod hosts.

scholarly journals Amplicon-Based Next Generation Sequencing for Rapid Identification of Rickettsia and Ectoparasite Species from Entomological Surveillance in Thailand

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 215
Author(s):  
Suwanna Chaorattanakawee ◽  
Achareeya Korkusol ◽  
Bousaraporn Tippayachai ◽  
Sommai Promsathaporn ◽  
Betty K. Poole-Smith ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Citrate Synthase ◽  
Spotted Fever ◽  
Domestic Animals ◽  
Spotted Fever Group ◽  
Next Generation ◽  
Entomological Surveillance ◽  
Rickettsia Species ◽  
Wide Range ◽  
Generation Sequencing

Background: Next generation sequencing (NGS) technology has been used for a wide range of epidemiological and surveillance studies. Here, we used amplicon-based NGS to species identify Rickettsia and their arthropod hosts from entomological surveillance. Methods: During 2015–2016, we screened 1825 samples of rodents and ectoparasites collected from rodents and domestic mammals (dog, cat, and cattle) across Thailand for Rickettsia. The citrate synthase gene was amplified to identify Rickettsia to species, while the Cytochrome Oxidase subunit I (COI) and subunit II (COII) genes were used as target genes for ectoparasite identification. All target gene amplicons were pooled for library preparation and sequenced with Illumina MiSeq platform. Result: The highest percentage of Rickettsia DNA was observed in fleas collected from domestic animals (56%) predominantly dogs. Only a few samples of ticks from domestic animals, rodent fleas, and rodent tissue were positive for Rickettisia DNA. NGS based characterization of Rickettsia by host identified Rickettsia asembonensis as the most common bacteria in positive fleas collected from dogs (83.2%) while “Candidatus Rickettsia senegalensis” was detected in only 16.8% of Rickettsia positive dog fleas. Sequence analysis of COI and COII revealed that almost all fleas collected from dogs were Ctenocephalides felis orientis. Other Rickettsia species were detected by NGS including Rickettsia heilongjiangensis from two Haemaphysalis hystricis ticks, and Rickettsia typhi in two rodent tissue samples. Conclusion: This study demonstrates the utility of NGS for high-throughput sequencing in the species characterization/identification of bacteria and ectoparasite for entomological surveillance of rickettsiae. A high percentage of C. f. orientis are positive for R. asembonensis. In addition, our findings indicate there is a risk of tick-borne Spotted Fever Group rickettsiosis, and flea-borne murine typhus transmission in Tak and Phangnga provinces of Thailand.

scholarly journals Spotted fever group rickettsial infection in dogs and their ticks from domestic–wildlife interface areas in southeastern Brazil

2020 ◽  
Vol 29 (1) ◽  
Author(s):  
Sabrina Destri Emmerick Campos ◽  
Nathalie Costa da Cunha ◽  
Camila de Souza Cerqueira Machado ◽  
Niara Vanat Nadal ◽  
Eloy Silva Seabra Junior ◽  
...  
Keyword(s):  
Natural Infection ◽  
Spotted Fever ◽  
Rhipicephalus Sanguineus ◽  
Southeastern Brazil ◽  
Spotted Fever Group ◽  
Forest Fragments ◽  
Rickettsia Parkeri ◽  
Chain Reactions ◽  
Glta Gene ◽  
Pcr Targeting

Abstract Rickettsia rickettsii is the causative agent of Brazilian spotted fever (BSF), for which humans and dogs are both susceptible. Dogs are sentinels in serological surveys, however, canine disease is rarely reported. Therefore, we aimed to evaluate natural infection by spotted fever group (SFG) Rickettsia spp. in dogs and ticks collected from domiciles close to forest fragments, featuring domestic–wildlife interface areas. Samples from 115 dogs and 135 ixodids were assessed by polymerase chain reactions (PCR) targeting the gltA gene for Rickettsia spp. and the ompA gene for the SFG rickettsial species. One dog (0.87%; 1/115) was positive for R. rickettsii. This dog presented nonspecific laboratory and clinical abnormalities (thrombocytopenia, hyperproteinemia, lymph node enlargement, emaciation, anorexia, and lethargy). Rickettsia parkeri was identified in 2.96% (4/135) of the ticks (Amblyomma sculptum, A. aureolatum, and Rhipicephalus sanguineus). This study confirmed the presence of SFG bacteria in non-endemic and preserved locations, where domestic and wild populations interact. We reinforce the fact that the dog is susceptible to natural R. rickettsii infection. Although this is a rare finding, preventive measures should be taken against BSF in the studied areas. Finally, R. parkeri infection is possibly being demonstrated in A. sculptum for the first time.

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 Significant Growth by Rickettsia Species within Human Macrophage-Like Cells Is a Phenotype Correlated with the Ability to Cause Disease in Mammals

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 228
Author(s):  
M. Nathan Kristof ◽  
Paige E. Allen ◽  
Lane D. Yutzy ◽  
Brandon Thibodaux ◽  
Christopher D. Paddock ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Spotted Fever ◽  
Growth Characteristic ◽  
Human Macrophage ◽  
Rickettsia Conorii ◽  
Spotted Fever Group ◽  
Rocky Mountain Spotted Fever ◽  
Phagocytic Cells ◽  
Pathogenic Potential ◽  
Rickettsia Species

Rickettsia are significant sources of tick-borne diseases in humans worldwide. In North America, two species in the spotted fever group of Rickettsia have been conclusively associated with disease of humans: Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, and Rickettsia parkeri, the cause of R. parkeri rickettsiosis. Previous work in our lab demonstrated non-endothelial parasitism by another pathogenic SFG Rickettsia species, Rickettsia conorii, within THP-1-derived macrophages, and we have hypothesized that this growth characteristic may be an underappreciated aspect of rickettsial pathogenesis in mammalian hosts. In this work, we demonstrated that multiple other recognized human pathogenic species of Rickettsia, including R. rickettsii, R. parkeri, Rickettsia africae, and Rickettsiaakari can grow within target endothelial cells as well as within PMA-differentiated THP-1 cells. In contrast, Rickettsia bellii, a Rickettsia species not associated with disease of humans, and R. rickettsii strain Iowa, an avirulent derivative of pathogenic R. rickettsii, could invade both cell types but proliferate only within endothelial cells. Further analysis revealed that similar to previous studies on R. conorii, other recognized pathogenic Rickettsia species could grow within the cytosol of THP-1-derived macrophages and avoided localization with two different markers of lysosomal compartments; LAMP-2 and cathepsin D. R. bellii, on the other hand, demonstrated significant co-localization with lysosomal compartments. Collectively, these findings suggest that the ability of pathogenic rickettsial species to establish a niche within macrophage-like cells could be an important factor in their ability to cause disease in mammals. These findings also suggest that analysis of growth within mammalian phagocytic cells may be useful to predict the pathogenic potential of newly isolated and identified Rickettsia species.

scholarly journals Rickettsia spp. in rodent-attached ticks and first evidence of Spotted fever Group Rickettsia species Candidatus Rickettsia uralica in Europe.

2020 ◽  
Author(s):  
Maria Vikentjeva ◽  
Julia Geller ◽  
Jaanus Remm ◽  
Irina Golovljova
Keyword(s):  
Spotted Fever ◽  
Ixodid Ticks ◽  
Distribution Area ◽  
Myodes Glareolus ◽  
Ixodes Persulcatus ◽  
Spotted Fever Group ◽  
Human Pathogens ◽  
Rickettsia Species ◽  
Questing Ticks ◽  
Spotted Fever Group Rickettsia

Abstract BACKGROUND Rickettsia spp. are human pathogens that cause a number of diseases and are transmitted by arthropods, including ixodid ticks. Estonia contributes a region, where the distribution area of two exophilic tick species of known medical importance, Ixodes persulcatus and I. ricinus, overlap. The presence of the nidicolous rodent-associated I. trianguliceps has recently been shown for Estonia. Although there is no Estonian data available on human disease caused by tick-borne Rickettsia spp., the presence of three Rickettsia species in non-nidicolous ticks, albiet at very dissimilar rates, was also previously reported. The aim of this studywas to screen, identify and characterize Rickettsia species in nidicolous and non-nidicolous ticks attached to rodents. RESULTS Nymphs and larvae of I. ricinus ( n = 1004), I . persulcatus ( n = 75) and I. trianguliceps ( n = 117) attached to rodents and shrews caught in different parts of Estonia were studied for the presence of Rickettsia spp. by nested PCR. Ticks were removed from 314 small animals of 5 species (bank voles Myodes glareolus , yellow necked mice Apodemus flavicollis , striped field mice A. agrarius, pine voles M. subterranius and common shrews S. araneus) . Rickettsial DNA was detected in 8,7% (103/1186) studied ticks. In addition to R. helvetica, previously found in questing ticks, this study reports the first identification of the recently described I. trianguliceps- associated Candidatus R. uralica in west of the Ural.

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