Epidemiology and molecular genetic characteristics of Lyme borreliosis pathogens circulating in tick’s population in the Almaty oblast of the Republic of Kazakhstan

Abstract

Background. Information on the geographical distribution of different species of the Borrelia burgdorferi sensu lato (B. burgdorferi s.l.) complex is of great epidemiological importance, since different genospecies are associated with certain clinical manifestations of Lyme borreliosis. Although Almaty region of the Republic of Kazakhstan is considered to be endemic for tick-borne borreliosis, there is still no accurate data on the level of borrelia infection in ticks in the region, including information on the genotypes of circulating borrelia.The aim of this work was to study ticks collected from humans in the Almaty region of the Republic of Kazakhstan in 2018.Materials and methods. Ticks were tested for the presence of B. burgdorferi s.l. DNA, genotyping of the identified borrelia was done by sequencing of the fragment of 16S rRNA gene. The analysis of epidemiological data on the incidence of Lyme borreliosis in the Almaty region in 2013–2018 was performed.Results. Rhipicephalus turanicus (116/253), Haemaphysalis punctata (74/253), Dermacentor marginatus (28/253), and Ixodes persulcatus (23/253) were the predominant species of ticks taken from humans. The prevalence of B. burgdorferi s.l. infection in I. persulcatus ticks was 39.13% (9/23) It should be noted that the DNA of B. burgdorferi s.l. was also detected in single individuals of D. marginatus, H. punctata, and R. turanicus, although these species are not considered as competent B. burgdorferi s.l. vectors.Conclusion. As a result of sequencing of the positive homogenates of ticks, two genotypes of B. burgdorferi s.l. were identified: B. afzelii and B. garinii and/or B. bavariensis. Thus, at least two genospecies, B. afzelii and B. garinii and/or B. bavariensis, circulate in the territory of the Almaty region.