Genetic diversity of Bartonella spp. in rodents and fleas from Poland

Abstract

Bartonella spp. are parasites of mammalian erythrocytes and endothelial cells, and are transmitted by blood-feeding arthropod ectoparasites, including fleas. This study aimed to: (i) identify the main flea species responsible for Bartonella transmission and the specific Bartonella species they carry, (ii) evaluate how host-related factors influence the prevalence of Bartonella, (iii) examine the genetic diversity of Bartonella from different flea species and mammalian hosts, including rodents and European moles, and (iv) determine the haplotypes of Bartonella derived from rodents. Blood samples were collected from seven rodent species and two European moles in Poland (n = 994), and fleas were collected from rodents (n = 833). Bartonella spp. were identified and genotyped through rpoB and gltA genes. Phylogenetic analysis revealed two dominant Bartonella spp. in rodents and fleas: B. grahamii and B. taylorii. Moreover, 17 haplotypes of B. taylorii and 9 of B. grahamii were identified. The sequences of Bartonella sp. from T. europaea clustered in a unique separate group, possibly indicating a novel species. The study confirmed fleas as vectors of Bartonella transmission in rodents and highlighted the significant genetic diversity of Bartonella spp. in both fleas and rodents.

Keywords: Bartonella; Ctenophthalmus.; Histrichopsylla. Fleas; Megabothris.; Haplotype; Poland; Rodents.

Fig. 1

Map of the study sites: (site 1 = Urwitałt, site 2 = Tałty, site 3 = Pilchy, Site 4 = Łuknajno, site 5 = Białobrzegi)

Fig. 2

(A) Prevalence of Bartonella spp. (%) in flea species. (B) Prevalnce of Bartonella spp. (%) by flea species and year of study. (C) Prevalence of Bartonella spp. (%), by flea sex and year of study. (D) Prevalence of Bartonella spp. (%), by study sites. (E) Prevalence of Bartonella spp. (%), by age class of host (rodents) and year of study.

Fig. 2

(A) Prevalence of Bartonella spp. (%) in flea species. (B) Prevalnce of Bartonella spp. (%) by flea species and year of study. (C) Prevalence of Bartonella spp. (%), by flea sex and year of study. (D) Prevalence of Bartonella spp. (%), by study sites. (E) Prevalence of Bartonella spp. (%), by age class of host (rodents) and year of study.

Fig. 3

(A) The phylogenetic tree of Bartonella spp. inferred from sequence variation of 860-bp rpoB gene fragment. The tree is 50%-majority rule consensus obtained using MrBayes (Bayesian Inference). Numbers along nodes represent a posteriori probability. The clades of B. taylorii and B. grahamii were collapsed into simplified forms for clarity. Custers of sequences obtained from Białobrzegi and Kury are highlighted in green and orange, respectively. (B) The phylogenetic tree of Bartonella spp. inferred from sequence variation of 860-bp rpoB gene fragment. The B. grahamii clade is shown in greater detail. (C) The phylogenetic tree of Bartonella spp. inferred from sequence variation of 860-bp rpoB gene fragment. The B. taylorii clade is shown in greater detail.

Fig. 3

(A) The phylogenetic tree of Bartonella spp. inferred from sequence variation of 860-bp rpoB gene fragment. The tree is 50%-majority rule consensus obtained using MrBayes (Bayesian Inference). Numbers along nodes represent a posteriori probability. The clades of B. taylorii and B. grahamii were collapsed into simplified forms for clarity. Custers of sequences obtained from Białobrzegi and Kury are highlighted in green and orange, respectively. (B) The phylogenetic tree of Bartonella spp. inferred from sequence variation of 860-bp rpoB gene fragment. The B. grahamii clade is shown in greater detail. (C) The phylogenetic tree of Bartonella spp. inferred from sequence variation of 860-bp rpoB gene fragment. The B. taylorii clade is shown in greater detail.

Fig. 3

(A) The phylogenetic tree of Bartonella spp. inferred from sequence variation of 860-bp rpoB gene fragment. The tree is 50%-majority rule consensus obtained using MrBayes (Bayesian Inference). Numbers along nodes represent a posteriori probability. The clades of B. taylorii and B. grahamii were collapsed into simplified forms for clarity. Custers of sequences obtained from Białobrzegi and Kury are highlighted in green and orange, respectively. (B) The phylogenetic tree of Bartonella spp. inferred from sequence variation of 860-bp rpoB gene fragment. The B. grahamii clade is shown in greater detail. (C) The phylogenetic tree of Bartonella spp. inferred from sequence variation of 860-bp rpoB gene fragment. The B. taylorii clade is shown in greater detail.

Fig. 4

The phylogenetic tree of Bartonella spp. inferred from sequence variation of 810-bp gltA gene fragment. The tree is 50%-majority rule consensus obtained using MrBayes (Bayesian Inference). Numbers along the nodes represent a posteriori probability. Clusters of sequences obtained from T. europaea from Kury are highlighted in red rectangular on the first clade.

Fig. 5

The phylogenetic tree of the 18 S rDNA of fleas was inferred by using the Maximum Likelihood method and Kimura 2-parameter model by MEGA11.

Fig. 6

The Minimum Spanning Network of the rpoB gene showing the relationship between the haplotypes. (A) Bartonella grahamii haplotypes based on the host and vector species; (B) Bartonella grahamii haplotypes based on the study sites; (C) Bartonella taylorii haplotypes based on the host and vector species; (D) Bartonella taylorii haplotypes based on the study sites.

Fig. 6

The Minimum Spanning Network of the rpoB gene showing the relationship between the haplotypes. (A) Bartonella grahamii haplotypes based on the host and vector species; (B) Bartonella grahamii haplotypes based on the study sites; (C) Bartonella taylorii haplotypes based on the host and vector species; (D) Bartonella taylorii haplotypes based on the study sites.