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

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.

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Knowledge, attitudes and practices towards spotted fever group rickettsioses and Q fever in Laikipia and Maasai Mara, Kenya

Journal of Public Health in Africa ◽

10.4081/jphia.2016.545 ◽

2016 ◽

Cited By ~ 1

Author(s):

David Ndeereh ◽

Gerald Muchemi ◽

Andrew Thaiyah

Keyword(s):

Q Fever ◽

Spotted Fever ◽

Medical Personnel ◽

Raw Milk ◽

Sub Saharan Africa ◽

Spotted Fever Group ◽

Health Providers ◽

Attitudes And Practices ◽

Local Residents ◽

Sub Saharan

Many factors contribute to misdiagnosis and underreporting of infectious zoonotic diseases in most sub-Saharan Africa including limited diagnostic capacity and poor knowledge. We assessed the knowledge, practices and attitudes towards spotted fever group rickettsioses (SFGR) and Q fever amongst local residents in Laikipia and Maasai Mara in Kenya. A semistructured questionnaire was administered to a total of 101 respondents including 51 pastoralists, 17 human health providers, 28 wildlife sector personnel and 5 veterinarians. The pastoralists expressed no knowledge about SFGR and Q fever. About 26.7% of the wildlife sector personnel in Laikipia expressed some knowledge about SFGR and none in Maasai Mara. None of these respondents had knowledge about Q fever. About 45.5 and 33.3% of the health providers in Laikipia and Maasai Mara respectively expressed knowledge about SFGR and 9.1% in Laikipia expressed good knowledge on Q fever and none in Maasai Mara. The diseases are not considered amongst potential causes of febrile illnesses in most medical facilities except in one facility in Laikipia. Majority of pastoralists practiced at least one predisposing activity for transmission of the diseases including consumption of raw milk, attending to parturition and sharing living accommodations with livestock. Education efforts to update knowledge on medical personnel and One-Health collaborations should be undertaken for more effective mitigation of zoonotic disease threats. The local communities should be sensitized through a multidisciplinary approach to avoid practices that can predispose them to the diseases.

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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

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/s0037-86822011005000037 ◽

2011 ◽

Vol 44 (3) ◽

pp. 313-317 ◽

Cited By ~ 2

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.

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

Microorganisms ◽

10.3390/microorganisms10010035 ◽

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.

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Molecular Detection of Spotted-Fever Group Rickettsiae in Ticks Collected from Domestic and Wild Animals in Corsica, France

Pathogens ◽

10.3390/pathogens8030138 ◽

2019 ◽

Vol 8 (3) ◽

pp. 138 ◽

Cited By ~ 3

Author(s):

Vincent Cicculli ◽

Maestrini Oscar ◽

Francois Casabianca ◽

Natacha Villechenaud ◽

Remi Charrel ◽

...

Keyword(s):

Spotted Fever ◽

Companion Animals ◽

Likelihood Estimation ◽

Ixodid Ticks ◽

Spotted Fever Group ◽

Wild Animals ◽

Wild Boars ◽

Glta Gene ◽

Rickettsia Slovaca ◽

Polymerase Chain

To obtain a better understanding of the current magnitude of tick-borne rickettsioses in Corsica, we used molecular methods to characterize the occurrence of Rickettsia spp. in ixodid ticks collected from domestic and wild animals. The presence of Rickettsia spp. was evaluated using real-time polymerase chain reaction targeting the gltA gene and by sequencing of gltA and ompA partial genes for species identification and phylogenetic analysis. Infection rates were calculated as the maximum-likelihood estimation (MLE) with 95% confidence intervals (CI). In total, 1117 ticks belonging to four genera (Rhipicephalus, Hyalomma, Ixodes, and Dermacentor) were collected from cattle, sheep, wild boars, and companion animals during July–August 2017 and July 2018–January 2019. Overall, Rickettsia DNA was detected in 208 of 349 pools of ticks (MLE = 25.6%, 95% CI: 22.6–28.8%). The molecular analysis revealed five different rickettsial species of the spotted-fever group (SFG). We highlighted the exclusive detection of Candidatus Ri. barbariae in R. bursa and of Ri. aeschlimanii in H. marginatum. Rickettsia slovaca was detected in D. marginatus collected from wild boars. This study provides the first evidence of the presence of Ri. monacensis in I. ricinus ticks isolated from a dog in Corsica. In conclusion, our data revealed wide dispersal of SFG Rickettsiae and their arthropod hosts in Corsica, highlighting the need for surveillance of the risk of infection for people living and/or working close to infected or infested animals.

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

Pathogens ◽

10.3390/pathogens10020215 ◽

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.

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Molecular Detection and Genetic Identification of Rickettsia Infection in Ixodes granulatus Ticks, an Incriminated Vector for Geographical Transmission in Taiwan

Microorganisms ◽

10.3390/microorganisms9061309 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1309

Author(s):

Chien-Ming Shih ◽

Pei-Wen Yang ◽

Li-Lian Chao

Keyword(s):

Infection Rate ◽

Citrate Synthase ◽

Phylogenetic Analyses ◽

Spotted Fever ◽

Genetic Identification ◽

Potential Threat ◽

Rickettsia Species ◽

Zoonotic Infections ◽

Glta Gene ◽

Ixodes Granulatus

Tick-borne Rickettsia pathogens have become an emerging source of zoonotic infections and have a major impact on human health worldwide. In this study, the prevalence and genetic identity of Rickettsia infections in Ixodes granulatus ticks was firstly determined in Kinmen Island of Taiwan. A total of 247 I. granulatus ticks were examined for Rickettsia infection by nested-PCR assay targeting the citrate synthase (gltA) gene of Rickettsia. The Rickettsia infection was detected with a general infection rate of 4.86%, and was detected in nymph, male and female stages with an infection rate of 3.81%, 0% and 6.84%, respectively. Phylogenetic relationships were analyzed by comparing the gltA sequences obtained from four Taiwan strains and 19 other strains representing 13 genospecies of Rickettsia. Phylogenetic analyses reveal that all Taiwan strains were genetically affiliated to the genospecies of spotted fever (R. parkeri) and transitional (R. felis) groups of Rickettsia. Our findings reveal the first detection of R. parkeri-like and R. felis in I. granulatus ticks from Kinmen Island. As a tourist island between Taiwan and mainland China, these results demonstrate the epidemiological significance of diverse Rickettsia species existed in I. granulatus ticks and highlight the potential threat of geographical transmission among humans in the Taiwan area.

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

Microorganisms ◽

10.3390/microorganisms8111670 ◽

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.

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Molecular Detection and Characterization of Rickettsia Species in Ixodid Ticks Collected From Cattle in Southern Zambia

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.684487 ◽

2021 ◽

Vol 8 ◽

Author(s):

Simbarashe Chitanga ◽

Kennedy Chibesa ◽

Karen Sichibalo ◽

Benjamin Mubemba ◽

King S. Nalubamba ◽

...

Keyword(s):

Citrate Synthase ◽

Pcr Amplification ◽

Human Infection ◽

Ixodid Ticks ◽

Sub Saharan Africa ◽

Rickettsia Species ◽

Phylogenetic Characterization ◽

Rickettsia Africae ◽

Sub Saharan ◽

First Time

Tick-borne zoonotic pathogens are increasingly becoming important across the world. In sub-Saharan Africa, tick-borne pathogens identified include viruses, bacteria and protozoa, with Rickettsia being the most frequently reported. This study was conducted to screen and identify Rickettsia species in ticks (Family Ixodidae) infesting livestock in selected districts of southern Zambia. A total of 236 ticks from three different genera (Amblyomma, Hyalomma, and Rhipicephalus) were collected over 14 months (May 2018–July 2019) and were subsequently screened for the presence of Rickettsia pathogens based on PCR amplification targeting the outer membrane protein B (ompB). An overall Rickettsia prevalence of 18.6% (44/236) was recorded. Multi-locus sequencing and phylogenetic characterization based on the ompB, ompA, 16S rRNA and citrate synthase (gltA) genes revealed the presence of Rickettsia africae (R. africae), R. aeschlimannii-like species and unidentified Rickettsia species. While R. aeschlimannii-like species are being reported for the first time in Zambia, R. africae has been reported previously, with our results showing a wider distribution of the bacteria in the country. Our study reveals the potential risk of human infection by zoonotic Rickettsia species and highlights the need for increased awareness of these infections in Zambia's public health systems.

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

10.21203/rs.3.rs-1082354/v1 ◽

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.

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Zoonotic Rickettsia Species in Small Ruminant Ticks From Tunisia

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.676896 ◽

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.

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