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 Expansion of Tick-Borne Rickettsioses in the World

2020 ◽  
Vol 8 (12) ◽  
pp. 1906
Author(s):  
Mariusz Piotrowski ◽  
Anna Rymaszewska
Keyword(s):  
Spotted Fever ◽  
Rapid Evolution ◽  
Diagnostic Techniques ◽  
Molecular Diagnostic ◽  
Molecular Diagnostic Techniques ◽  
Spotted Fever Group ◽  
Rickettsia Species ◽  
The World ◽  
New Locations ◽  
Obligate Intracellular Bacteria

Tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus Rickettsia. These infections are among the oldest known diseases transmitted by vectors. In the last three decades there has been a rapid increase in the recognition of this disease complex. This unusual expansion of information was mainly caused by the development of molecular diagnostic techniques that have facilitated the identification of new and previously recognized rickettsiae. A lot of currently known bacteria of the genus Rickettsia have been considered nonpathogenic for years, and moreover, many new species have been identified with unknown pathogenicity. The genus Rickettsia is distributed all over the world. Many Rickettsia species are present on several continents. The geographical distribution of rickettsiae is related to their vectors. New cases of rickettsioses and new locations, where the presence of these bacteria is recognized, are still being identified. The variety and rapid evolution of the distribution and density of ticks and diseases which they transmit shows us the scale of the problem. This review article presents a comparison of the current understanding of the geographic distribution of pathogenic Rickettsia species to that of the beginning of the century.

scholarly journals Rickettsia parkeri: a Rickettsial pathogen transmitted by ticks in endemic areas for spotted fever rickettsiosis in southern Uruguay

2012 ◽  
Vol 54 (3) ◽  
pp. 131-134 ◽  
Author(s):  
José M. Venzal ◽  
Agustín Estrada-Peña ◽  
Aránzazu Portillo ◽  
Atilio J. Mangold ◽  
Oscar Castro ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Spotted Fever ◽  
Rhipicephalus Sanguineus ◽  
Rickettsia Conorii ◽  
Spotted Fever Group ◽  
Rickettsia Parkeri ◽  
Molecular Tests ◽  
Glta Gene ◽  
Dna Pools ◽  
Human Infections

At first Rickettsia conorii was implicated as the causative agent of spotted fever in Uruguay diagnosed by serological assays. Later Rickettsia parkeri was detected in human-biting Amblyomma triste ticks using molecular tests. The natural vector of R. conorii, Rhipicephalus sanguineus, has not been studied for the presence of rickettsial organisms in Uruguay. To address this question, 180 R. sanguineus from dogs and 245 A. triste from vegetation (flagging) collected in three endemic localities were screened for spotted fever group (SFG) rickettsiosis in southern Uruguay. Tick extracted DNA pools were subjected to PCR using primers which amplify a fragment of the rickettsial gltA gene. Positive tick DNA pools with these primers were subjected to a second PCR round with primers targeting a fragment of the ompA gene, which is only present in SFG rickettsiae. No rickettsial DNA was detected in R. sanguineus. However, DNA pools of A. triste were found to be positive for a rickettsial organism in two of the three localities, with prevalences of 11.8% to 37.5% positive pools. DNA sequences generated from these PCR-positive ticks corresponded to R. parkeri. These findings, joint with the aggressiveness shown by A. triste towards humans, support previous data on the involvement of A. triste as vector of human infections caused by R. parkeri in Uruguay.

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 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.

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 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 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.

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 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.

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