Spotted fever group (SFG) rickettsiae are obligate intracellular Gram-negative bacteria mainly associated with ticks. In Japan, several hundred cases of Japanese spotted fever, caused by Rickettsia japonica, are reported annually. Other Rickettsia species are also known to exist in ixodid ticks; however, their phylogenetic position and pathogenic potential are poorly understood. We conducted a nationwide cross-sectional survey on questing ticks to understand the overall diversity of SFG rickettsiae in Japan. Out of 2,189 individuals (19 tick species in 4 genera), 373 (17.0%) samples were positive for Rickettsia spp. as ascertained by real-time PCR amplification of the citrate synthase gene (gltA). Conventional PCR and sequencing analyses of gltA indicated the presence of 15 different genotypes of SFG rickettsiae. Based on the analysis of five additional genes, we characterised five Rickettsia species; R. asiatica, R. helvetica, R. monacensis (formerly reported as Rickettsia sp. In56 in Japan), R. tamurae, and Candidatus R. tarasevichiae and several unclassified SFG rickettsiae. We also found a strong association between rickettsial genotypes and their host tick species, while there was little association between rickettsial genotypes and their geographical origins. These observations suggested that most of the SFG rickettsiae have a limited host range and are maintained in certain tick species in the natural environment.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6365641 | PMC |
| http://dx.doi.org/10.1038/s41598-018-37836-5 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Molecular identification of tick (Acari: Ixodidae) and tick-borne pathogens from Przewalski's gazelle (Procapra Przewalskii) and Tibetan sheep (Ovis aries) in Qinghai Lake National Nature Reserve, China.
Heliyon
December 2024
Qinghai University State Key Laboratory of Plateau Ecology and Agriculture, Xining, 810016, Qinghai, China.
The Qinghai Lake National Nature Reserve (QLNNR), renowned for its abundant natural resources and diverse ecological habitats, serves as an ideal environment for ticks, thereby increasing the risk of various tick-borne pathogens (TBPs) transmission. This study aimed to investigate the prevalence of TBPs in ticks collected from Przewalski's gazelle and Tibetan sheep within the QLNNR. A total of 313 tick samples were collected from the vicinity of Qinghai Lake.
View Article and Find Full Text PDFLimited evidence of infection with other tick-borne pathogens in patients tested for Lyme neuroborreliosis in the Netherlands.
Ticks Tick Borne Dis
November 2024
Amsterdam UMC Multidisciplinary Lyme Borreliosis Center, Amsterdam UMC, Amsterdam, the Netherlands; Center for Experimental and Molecular Medicine, Amsterdam UMC, Amsterdam, the Netherlands; Amsterdam Institute for Immunology & Infectious diseases, Amsterdam UMC, Amsterdam, the Netherlands. Electronic address:
Ixodes ricinus is the main vector of the causative agents of Lyme neuroborreliosis. This tick species can also transmit tick-borne encephalitis virus (TBEV), spotted fever group (SFG) Rickettsia and Borrelia miyamotoi to humans. These tick-borne pathogens are present in Dutch ticks and have also been associated with human neurological infections, but well characterized disease cases are seldom reported.
View Article and Find Full Text PDFPrevalence and diversity of spotted fever group Rickettsia species in ixodid ticks from domestic dogs in Chad, Africa.
Ticks Tick Borne Dis
November 2024
Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, Wildlife Health Building, 589 D.W. Brooks Dr., University of Georgia, Athens, GA, 30602, USA; Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA; Center for Ecology of Infectious Diseases, University of Georgia, Athens, GA, 30602, USA. Electronic address:
Article Synopsis
- Tick-borne pathogens from the Rickettsia genus cause serious diseases in humans and dogs, and climate and land use changes are expanding their vector ranges, potentially introducing new pathogens in unexposed areas.
- A study in Chad found that 43.3% of ticks from domestic dogs were positive for Rickettsia spp., with six identified species including some known zoonotic pathogens like R. africae and R. felis.
- The results highlight a significant diversity of Rickettsia in ticks, particularly in Rh. muhsamae, indicating a risk of rickettsiosis in Chad, and emphasize the need for more research on ticks and these pathogens in the region.
First molecular diagnosis of the human pathogen Rickettsia raoultii and other spotted fever group rickettsiae in Sudanese ixodid ticks from domestic ruminants.
Vet Med Sci
November 2024
Central Laboratory, Ministry of Higher Education and Scientific Research, Khartoum, Sudan.
Article Synopsis
- Rickettsial infections are often overlooked by doctors in tropical and subtropical regions, despite new findings and reports highlighting their presence and potential risks.
- This study specifically aimed to identify and characterize spotted fever group (SFG) rickettsiae in ticks found on domestic ruminants in Khartoum State, utilizing PCR methods for genetic analysis.
- The results showed that SFG rickettsiae were present in the examined ticks, identifying four different species, which suggests a risk for human infections, especially in cases of fever with no known cause.
Discovery of a novel spotted fever group Rickettsia, "Candidatus Rickettsia kedanie," in unfed larval chigger mites, Leptotrombidium scutellare.
Microbiol Immunol
September 2024
Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan.
Spotted fever group (SFG) rickettsia, the causative agent of SFG rickettsiosis, is predominantly carried by ticks, whereas Orientia tsutusgamushi, the causative agent of scrub typhus, is primarily transmitted by chigger mites in Japan. In this study, we attempted to isolate intracellular eubacteria from Leptotrombidium scutellare, a major vector of O. tsutsugamushi; moreover, we isolated an SFG rickettsia using a mosquito-derived cell line.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!