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Published on: October 6, 2018
Rickettsia sp. strain RpA4 detected in Portuguese Dermacentor marginatus ticks
Liliana Vitorino1, Rita De Sousa, Fatima Bacellar
1Universidade de Lisboa, Faculdade de Ciàncias, Centro de Genética e Biologia Molecular and Instituto de Ciància Aplicada e Tecnologia, Edifício ICAT, Campus FCUL, Campo Grande, Lisboa, Portugal.
Abstract:
Dermacentor marginatus species is the common vector of Rickettsia slovaca. Recently, a new rickettsia genotype, RpA4, was detected in several Dermacentor sp. ticks in several countries of the former Soviet Union and in Spain. In an epidemiological surveillance study, ninety-eight D. marginatus, collected in the South of Portugal in spring of 2003 and 2004, were screened by polymerase chain reaction (PCR) to detect Rickettsiae. Overall, 59.2% of the ticks were PCR-positive, among them 34.5% were proved to be infected with R. slovaca and 65.5% with Rickettsia sp. RpA4. This study reports for the first time a high prevalence of Rickettsia sp. RpA4 in D. marginatus in Portugal, pointing out for a wider geographic distribution of this genotype than previously reported.
Insights
This study found Rickettsia sp. RpA4 in Dermacentor marginatus ticks in Portugal, indicating a wider distribution for this emerging Rickettsia genotype. The research highlights the prevalence of this pathogen in tick populations.
Area of Science:
- Veterinary Entomology
- Molecular Epidemiology
- Tick-borne Diseases
Background:
- Dermacentor marginatus ticks are known vectors of Rickettsia slovaca.
- A novel Rickettsia genotype, RpA4, has been recently identified in Dermacentor ticks across Eurasia and Spain.
Purpose of the Study:
- To investigate the prevalence of Rickettsia species, including R. slovaca and R. sp. RpA4, in D. marginatus ticks from Southern Portugal.
- To determine the geographic distribution of Rickettsia sp. RpA4.
Main Methods:
- Epidemiological surveillance of D. marginatus ticks collected in Southern Portugal during 2003-2004.
- Polymerase chain reaction (PCR) screening to detect Rickettsiae DNA within tick samples.
Main Results:
- 59.2% of the 98 D. marginatus ticks tested were positive for Rickettsiae.
- Rickettsia slovaca was detected in 34.5% of positive ticks, while Rickettsia sp. RpA4 was found in 65.5% of positive ticks.
- This study is the first to report a high prevalence of Rickettsia sp. RpA4 in D. marginatus in Portugal.
Conclusions:
- Dermacentor marginatus ticks in Portugal harbor a significant prevalence of Rickettsia sp. RpA4.
- The findings suggest a broader geographic distribution of Rickettsia sp. RpA4 than previously understood.
- This highlights the importance of ongoing tick surveillance for emerging Rickettsial genotypes.
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