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Identification of tick-borne pathogens in ticks feeding on humans in Turkey.

Orkun Ö, Karaer Z, Çakmak A, Nalbantoğlu S - PLoS Negl Trop Dis (2014)

Bottom Line: In addition, B. crassa, for which limited information is available on its distribution and vector species, and B. occultans, for which no conclusive information is available on its presence in Turkey, were identified in Ha. parva and H. marginatum, respectively.More epidemiological studies are warranted for B. rossi, which is very pathogenic for dogs, because the presented results suggest that B. rossi might have a wide distribution in Turkey.Furthermore, we recommend that tick-borne pathogens, especially R. aeschlimannii, R. slovaca, and B. burgdorferi sensu stricto, should be taken into consideration in patients who had a tick bite in Turkey.

View Article: PubMed Central - PubMed

Affiliation: Department of Parasitology, Faculty of Veterinary Medicine, Ankara University, Ankara, Turkey.

ABSTRACT

Background: The importance of tick-borne diseases is increasing all over the world, including Turkey. The tick-borne disease outbreaks reported in recent years and the abundance of tick species and the existence of suitable habitats increase the importance of studies related to the epidemiology of ticks and tick-borne pathogens in Turkey. The aim of this study was to investigate the presence of and to determine the infection rates of some tick-borne pathogens, including Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae in the ticks removed from humans in different parts of Ankara.

Methodology/principal findings: A total of 169 ticks belonging to the genus Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus were collected by removing from humans in different parts of Ankara. Ticks were molecularly screened for Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae by PCR and sequencing analysis. We detected 4 Babesia spp.; B. crassa, B. major, B. occultans and B. rossi, one Borrelia spp.; B. burgdorferi sensu stricto and 3 spotted fever group rickettsiae; R. aeschlimannii, R. slovaca and R. hoogstraalii in the tick specimens analyzed. This is the report showing the presence of B. rossi in a region that is out of Africa and in the host species Ha. parva. In addition, B. crassa, for which limited information is available on its distribution and vector species, and B. occultans, for which no conclusive information is available on its presence in Turkey, were identified in Ha. parva and H. marginatum, respectively. Two human pathogenic rickettsia species (R. aeschlimannii and R. slovaca) were detected with a high prevalence in ticks. Additionally, B. burgdorferi sensu stricto was detected in unusual tick species (H. marginatum, H. excavatum, Hyalomma spp. (nymph) and Ha. parva).

Conclusions/significance: This study investigates both the distribution of several tick-borne pathogens affecting humans and animals, and the presence of new tick-borne pathogens in Turkey. More epidemiological studies are warranted for B. rossi, which is very pathogenic for dogs, because the presented results suggest that B. rossi might have a wide distribution in Turkey. Furthermore, we recommend that tick-borne pathogens, especially R. aeschlimannii, R. slovaca, and B. burgdorferi sensu stricto, should be taken into consideration in patients who had a tick bite in Turkey.

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Phylogenetic tree based on aligned sequences of the rickettsial ompA gene and constructed by using the Neighbor-Joining method in MEGA5.1 software.The rickettsial sequences obtained in this study are shown in a bold font. GenBank accession numbers of sequences and names of lineages are given before species names.
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pntd-0003067-g004: Phylogenetic tree based on aligned sequences of the rickettsial ompA gene and constructed by using the Neighbor-Joining method in MEGA5.1 software.The rickettsial sequences obtained in this study are shown in a bold font. GenBank accession numbers of sequences and names of lineages are given before species names.

Mentions: Spotted fever group rickettsiae have recently been found with remarkable infection rates in ticks in Turkey [10], [12]. Likewise, spotted fever group rickettsiae were the most commonly observed agents with 27.2% in this study (Table 1). Two human pathogenic rickettsial species (R. aeschlimannii and R. slovaca) and one species (R. hoogstraalii) with unknown pathogenicity were detected in ticks. Among them, R. aeschlimannii is transmitted mainly by Hyalomma ticks [46]. This bacterium was found in 5 H. marginatum, 2 H. aegyptium, and 1 H. excavatum in this study. As a result of the ompA gene sequence, R. aeschlimannii sequences obtained in this study are by 99.8–100% similar to the reference strains (R. aeschlimannii strain EgyRickHimp-El-Arish-17, accession no. HQ335158 and strain TR/Orkun-H.agyp86/Ankara accession no. JQ691728). In Turkey, R. aeschlimannii was found in 5 H. aegyptium, 2 H. marginatum, and one Rh. bursa collected from humans in Istanbul [10]. In our previous study, this pathogen was detected (in 32% of Rickettsia-positive ticks) in 3 H. marginatum, 2 H. aegyptium (unfed), 2 Hyalomma spp. (nymph), 1 Rh. turanicus collected from humans and animals in Kırşehir and Ankara [12]. These results show that our findings are in parallel with the previous findings. Rickettsia slovaca, the etiological agent of Tick-borne lymphadenopathy/Dermacentor-borne necrosis erythema and lymphadenopathy (TIBOLA/DEBONEL) [47], was detected in 16 D. marginatus, which are 64 percent of the total D. marginatus ticks (Table 1). According to ompA sequence, R. slovaca sequences detected in this study have 99.8–100% similarity with the reference strains (R. slovaca 13-B, accession no. CP002428, and strain TR/Orkun-D.marg79/Ankara accession no. JQ691724). Previously, we had detected this bacterium in 8 D. marginatus (80% of total D. marginatus ticks) collected from human and cattle in Ankara [12]. As a result, we again stress that R. aeschlimannii and R. slovaca are significant disease agents for humans and should not be neglected in this area. The clinical signs caused by these pathogens should be considered in the differential diagnosis of the tick-borne diseases in patients. Additionally, we detected R. hoogstraalii, a rickettsia with an unknown pathogenicity [48], in 22 out of 35 Ha. parva ticks collected (Table 1). According to the gltA gene sequence, the sequences obtained from this study are 100% similar to R. hoogstraalii strain TR/Orkun-Ha.parva164/Ankara (accession no JQ691712). In Turkey, R. hoogstraalii had been detected in 4 Ha. parva collected from humans in Ankara in our previous study [12]. The pathogenicity of R. hoogstraalii is unknown, but this rickettsia is widespread in Ha. parva ticks in this area. The nucleotide similarities of rickettsial sequences detected in this study and phylogenetic relationships are shown in detail in Table 2 and Figs. 4–5, respectively.


Identification of tick-borne pathogens in ticks feeding on humans in Turkey.

Orkun Ö, Karaer Z, Çakmak A, Nalbantoğlu S - PLoS Negl Trop Dis (2014)

Phylogenetic tree based on aligned sequences of the rickettsial ompA gene and constructed by using the Neighbor-Joining method in MEGA5.1 software.The rickettsial sequences obtained in this study are shown in a bold font. GenBank accession numbers of sequences and names of lineages are given before species names.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4125308&req=5

pntd-0003067-g004: Phylogenetic tree based on aligned sequences of the rickettsial ompA gene and constructed by using the Neighbor-Joining method in MEGA5.1 software.The rickettsial sequences obtained in this study are shown in a bold font. GenBank accession numbers of sequences and names of lineages are given before species names.
Mentions: Spotted fever group rickettsiae have recently been found with remarkable infection rates in ticks in Turkey [10], [12]. Likewise, spotted fever group rickettsiae were the most commonly observed agents with 27.2% in this study (Table 1). Two human pathogenic rickettsial species (R. aeschlimannii and R. slovaca) and one species (R. hoogstraalii) with unknown pathogenicity were detected in ticks. Among them, R. aeschlimannii is transmitted mainly by Hyalomma ticks [46]. This bacterium was found in 5 H. marginatum, 2 H. aegyptium, and 1 H. excavatum in this study. As a result of the ompA gene sequence, R. aeschlimannii sequences obtained in this study are by 99.8–100% similar to the reference strains (R. aeschlimannii strain EgyRickHimp-El-Arish-17, accession no. HQ335158 and strain TR/Orkun-H.agyp86/Ankara accession no. JQ691728). In Turkey, R. aeschlimannii was found in 5 H. aegyptium, 2 H. marginatum, and one Rh. bursa collected from humans in Istanbul [10]. In our previous study, this pathogen was detected (in 32% of Rickettsia-positive ticks) in 3 H. marginatum, 2 H. aegyptium (unfed), 2 Hyalomma spp. (nymph), 1 Rh. turanicus collected from humans and animals in Kırşehir and Ankara [12]. These results show that our findings are in parallel with the previous findings. Rickettsia slovaca, the etiological agent of Tick-borne lymphadenopathy/Dermacentor-borne necrosis erythema and lymphadenopathy (TIBOLA/DEBONEL) [47], was detected in 16 D. marginatus, which are 64 percent of the total D. marginatus ticks (Table 1). According to ompA sequence, R. slovaca sequences detected in this study have 99.8–100% similarity with the reference strains (R. slovaca 13-B, accession no. CP002428, and strain TR/Orkun-D.marg79/Ankara accession no. JQ691724). Previously, we had detected this bacterium in 8 D. marginatus (80% of total D. marginatus ticks) collected from human and cattle in Ankara [12]. As a result, we again stress that R. aeschlimannii and R. slovaca are significant disease agents for humans and should not be neglected in this area. The clinical signs caused by these pathogens should be considered in the differential diagnosis of the tick-borne diseases in patients. Additionally, we detected R. hoogstraalii, a rickettsia with an unknown pathogenicity [48], in 22 out of 35 Ha. parva ticks collected (Table 1). According to the gltA gene sequence, the sequences obtained from this study are 100% similar to R. hoogstraalii strain TR/Orkun-Ha.parva164/Ankara (accession no JQ691712). In Turkey, R. hoogstraalii had been detected in 4 Ha. parva collected from humans in Ankara in our previous study [12]. The pathogenicity of R. hoogstraalii is unknown, but this rickettsia is widespread in Ha. parva ticks in this area. The nucleotide similarities of rickettsial sequences detected in this study and phylogenetic relationships are shown in detail in Table 2 and Figs. 4–5, respectively.

Bottom Line: In addition, B. crassa, for which limited information is available on its distribution and vector species, and B. occultans, for which no conclusive information is available on its presence in Turkey, were identified in Ha. parva and H. marginatum, respectively.More epidemiological studies are warranted for B. rossi, which is very pathogenic for dogs, because the presented results suggest that B. rossi might have a wide distribution in Turkey.Furthermore, we recommend that tick-borne pathogens, especially R. aeschlimannii, R. slovaca, and B. burgdorferi sensu stricto, should be taken into consideration in patients who had a tick bite in Turkey.

View Article: PubMed Central - PubMed

Affiliation: Department of Parasitology, Faculty of Veterinary Medicine, Ankara University, Ankara, Turkey.

ABSTRACT

Background: The importance of tick-borne diseases is increasing all over the world, including Turkey. The tick-borne disease outbreaks reported in recent years and the abundance of tick species and the existence of suitable habitats increase the importance of studies related to the epidemiology of ticks and tick-borne pathogens in Turkey. The aim of this study was to investigate the presence of and to determine the infection rates of some tick-borne pathogens, including Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae in the ticks removed from humans in different parts of Ankara.

Methodology/principal findings: A total of 169 ticks belonging to the genus Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus were collected by removing from humans in different parts of Ankara. Ticks were molecularly screened for Babesia spp., Borrelia burgdorferi sensu lato and spotted fever group rickettsiae by PCR and sequencing analysis. We detected 4 Babesia spp.; B. crassa, B. major, B. occultans and B. rossi, one Borrelia spp.; B. burgdorferi sensu stricto and 3 spotted fever group rickettsiae; R. aeschlimannii, R. slovaca and R. hoogstraalii in the tick specimens analyzed. This is the report showing the presence of B. rossi in a region that is out of Africa and in the host species Ha. parva. In addition, B. crassa, for which limited information is available on its distribution and vector species, and B. occultans, for which no conclusive information is available on its presence in Turkey, were identified in Ha. parva and H. marginatum, respectively. Two human pathogenic rickettsia species (R. aeschlimannii and R. slovaca) were detected with a high prevalence in ticks. Additionally, B. burgdorferi sensu stricto was detected in unusual tick species (H. marginatum, H. excavatum, Hyalomma spp. (nymph) and Ha. parva).

Conclusions/significance: This study investigates both the distribution of several tick-borne pathogens affecting humans and animals, and the presence of new tick-borne pathogens in Turkey. More epidemiological studies are warranted for B. rossi, which is very pathogenic for dogs, because the presented results suggest that B. rossi might have a wide distribution in Turkey. Furthermore, we recommend that tick-borne pathogens, especially R. aeschlimannii, R. slovaca, and B. burgdorferi sensu stricto, should be taken into consideration in patients who had a tick bite in Turkey.

Show MeSH
Related in: MedlinePlus