New Rickettsiae in ticks collected in territories of the former soviet union

Area of Science:

• Veterinary Entomology
• Molecular Microbiology
• Infectious Diseases

Background:

• Ticks are significant vectors for various bacterial pathogens, impacting animal and human health.
• Rickettsia species, particularly those within the R. massiliae genogroup, are emerging concerns in endemic regions.
• Previous studies have highlighted the presence of Rickettsia in tick populations across Eurasia.

Purpose of the Study:

• To investigate the prevalence of Rickettsia infections in specific tick populations from Siberia and Crimea.
• To identify and characterize novel Rickettsia species within the R. massiliae genogroup found in these ticks.
• To utilize molecular techniques for accurate identification and phylogenetic analysis of detected Rickettsiae.

Main Methods:

• Collection and identification of tick species: Dermacentor nuttallii (Siberia), Rhipicephalus sanguineus (Crimea), and Rh. pumilio (Astrakhan region).
• Molecular detection of Rickettsia DNA using PCR.
• Sequencing of specific genes (16S rDNA, gltA, ompA) for species identification and phylogenetic analysis.

Main Results:

• Infection rates: Rickettsia sibirica (12%) in D. nuttallii, R. conorii (8%) in R. sanguineus, and the Astrakhan fever agent (3%) in Rh. pumilio.
• Identification of three previously undescribed Rickettsia species belonging to the R. massiliae genogroup.
• Phylogenetic analysis confirmed the distinctness of the newly identified Rickettsiae based on sequence data.

Conclusions:

• The study confirms the presence of known Rickettsia species in geographically distinct tick populations.
• Three novel Rickettsia species within the R. massiliae genogroup have been discovered in Siberian and Crimean ticks.
• These findings expand our understanding of Rickettsia diversity and their potential role as pathogens in these regions.