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Ticks and Tick-borne Diseases Jan 2021Borrelia miyamotoi is a tick-borne spirochete of the relapsing fever borrelia group and an emerging pathogen of public health significance. The genomes of relapsing...
Borrelia miyamotoi is a tick-borne spirochete of the relapsing fever borrelia group and an emerging pathogen of public health significance. The genomes of relapsing fever borreliae and Lyme disease borreliae consist of multiple linear and circular plasmids in addition to the chromosome. Previous work with B. burgdorferi sensu lato found diminished infectivity upon continuous in vitro culture passage that was attributable to plasmid loss. The effect of long-term culture passage on B. miyamotoi is not known. We generated a series of plasmid-specific primer sets and developed a multiplex PCR assay to detect the 14 known plasmids of B. miyamotoi North American strains LB-2001 and CT13-2396. We assessed the plasmid content of B. miyamotoi LB-2001 over 64 culture passages spanning 15 months and determined that strain LB-2001 retained all plasmids upon prolonged in vitro cultivation and remained infectious in mice. We also found that strain LB-2001 lacks plasmid lp20-1 which is present in strain CT13-2396. These results suggest that B. miyamotoi remains genetically stable when cultured and passaged in vitro.
Topics: Animals; Bacteriological Techniques; Borrelia; Female; Mice; Multiplex Polymerase Chain Reaction; Phenotype; Plasmids; Relapsing Fever
PubMed: 33074149
DOI: 10.1016/j.ttbdis.2020.101587 -
Scientific Reports Mar 2021Borrelia miyamotoi, a relapsing fever spirochete transmitted by Ixodid ticks causes B. miyamotoi disease (BMD). To evade the human host´s immune response, relapsing...
Borrelia miyamotoi, a relapsing fever spirochete transmitted by Ixodid ticks causes B. miyamotoi disease (BMD). To evade the human host´s immune response, relapsing fever borreliae, including B. miyamotoi, produce distinct variable major proteins. Here, we investigated Vsp1, Vlp15/16, and Vlp18 all of which are currently being evaluated as antigens for the serodiagnosis of BMD. Comparative analyses identified Vlp15/16 but not Vsp1 and Vlp18 as a plasminogen-interacting protein of B. miyamotoi. Furthermore, Vlp15/16 bound plasminogen in a dose-dependent fashion with high affinity. Binding of plasminogen to Vlp15/16 was significantly inhibited by the lysine analog tranexamic acid suggesting that the protein-protein interaction is mediated by lysine residues. By contrast, ionic strength did not have an effect on binding of plasminogen to Vlp15/16. Of relevance, plasminogen bound to the borrelial protein cleaved the chromogenic substrate S-2251 upon conversion by urokinase-type plasminogen activator (uPa), demonstrating it retained its physiological activity. Interestingly, further analyses revealed a complement inhibitory activity of Vlp15/16 and Vlp18 on the alternative pathway by a Factor H-independent mechanism. More importantly, both borrelial proteins protect serum sensitive Borrelia garinii cells from complement-mediated lysis suggesting multiple roles of these two variable major proteins in immune evasion of B. miyamotoi.
Topics: Bacterial Proteins; Borrelia; Complement System Proteins; Humans; Plasminogen
PubMed: 33654183
DOI: 10.1038/s41598-021-84533-x -
Zoonoses and Public Health May 2022For more than three decades, it has been recognized that Ixodes ricinus ticks occur in urban green space in Europe and that they harbour multiple pathogens linked to... (Review)
Review
For more than three decades, it has been recognized that Ixodes ricinus ticks occur in urban green space in Europe and that they harbour multiple pathogens linked to both human and animal diseases. Urban green space use for health and well-being, climate mitigation or biodiversity goals is promoted, often without consideration for the potential impact on tick encounters or tick-borne disease outcomes. This review synthesizes the results of over 100 publications on questing I. ricinus and Borrelia spp. infections in ticks in urban green space in 24 European countries. It presents data on several risk indicators for Lyme borreliosis and highlights key research gaps and recommendations for future studies. Across Europe, mean density of I. ricinus in urban green space was 6.9 (range; 0.1-28.8) per 100 m and mean Borrelia prevalence was 17.3% (range; 3.1%-38.1%). Similar density estimates were obtained for nymphs, which had a Borrelia prevalence of 14.2% (range; 0.5%-86.7%). Few studies provided data on both questing nymph density and Borrelia prevalence, but those that did found an average of 1.7 (range; 0-5.6) Borrelia-infected nymphs per 100 m of urban green space. Although a wide range of genospecies were reported, Borrelia afzelii was the most common in most parts of Europe, except for England where B. garinii was more common. The emerging pathogen Borrelia miyamotoi was also found in several countries, but with a much lower prevalence (1.5%). Our review highlights that I. ricinus and tick-borne Borrelia pathogens are found in a wide range of urban green space habitats and across several seasons. The impact of human exposure to I. ricinus and subsequent Lyme borreliosis incidence in urban green space has not been quantified. There is also a need to standardize sampling protocols to generate better baseline data for the density of ticks and Borrelia prevalence in urban areas.
Topics: Animals; Borrelia; Europe; Ixodes; Lyme Disease; Nymph; Parks, Recreational
PubMed: 35122422
DOI: 10.1111/zph.12913 -
Emerging Microbes & Infections Dec 2022We identified relapsing fever (RF) in 1.45% (145/10426) of the ticks and 1.40% (40/2850) of the wild mammals in a field investigation in China. Three RF species,...
We identified relapsing fever (RF) in 1.45% (145/10426) of the ticks and 1.40% (40/2850) of the wild mammals in a field investigation in China. Three RF species, including human-pathogenic , a and unclassified sp. were determined. Main species determined from ticks was (44.14%), followed by the unclassified sp. (42.76%), and (13.10%). In wild mammals, main species found was (57.50%), followed by the unclassified sp. (40.00%), and (2.50%). We determined and in China for the first time The coexistence of RF species in one tick species in a given region was observed, with the most frequent coexistence seen for and the unclassified sp. in respectively. The wide distribution and high variety of RF in China pose a potential threat to public health.
Topics: Animals; Humans; Relapsing Fever; Borrelia; Ixodes; Ixodidae; China; Mammals
PubMed: 36214427
DOI: 10.1080/22221751.2022.2134054 -
Internal Medicine (Tokyo, Japan) Sep 2018
PubMed: 29607948
DOI: 10.2169/internalmedicine.0432-17 -
Parasites & Vectors Feb 2020Ixodes ricinus is the most common tick species in Europe and the main vector for Borrelia burgdorferi (sensu lato) and tick-borne encephalitis virus (TBEV). It is...
BACKGROUND
Ixodes ricinus is the most common tick species in Europe and the main vector for Borrelia burgdorferi (sensu lato) and tick-borne encephalitis virus (TBEV). It is involved also in the transmission of Borrelia miyamotoi, a relapsing fever spirochete that causes health disorders in humans. Little is known regarding the circulation of Borrelia species and the natural foci of TBEV in north-eastern Germany. The goal of this study was to investigate the infection rates of Borrelia spp. and of TBEV in I. ricinus ticks from north-eastern Germany.
METHODS
Ticks were collected by flagging from 14 forest sites in Mecklenburg-Western Pomerania between April and October 2018. RNA and DNA extraction was performed from individual adult ticks and from pools of 2-10 nymphs. Real time reverse transcription PCR (RT-qPCR) targeted the 3' non-coding region of TBEV, while DNA of Borrelia spp. was tested by nested PCR for the amplification of 16S-23S intergenic spacer. Multilocus sequence typing (MLST) was performed on B. miyamotoi isolates.
RESULTS
In total, 2407 ticks were collected (239 females, 232 males and 1936 nymphs). Female and male I. ricinus ticks had identical infection rates (both 12.1%) for Borrelia spp., while nymphal pools showed a minimum infection rate (MIR) of 3.3%. Sequencing revealed four Borrelia species: B. afzelii, B. garinii, B. valaisiana and B. miyamotoi. Borrelia afzelii had the highest prevalence in adult ticks (5.5%) and nymphs (MIR of 1.8%). Borrelia miyamotoi was identified in 3.0% of adults and registered the MIR of 0.8% in nymphs. Borrelia valaisiana was confirmed in 2.5% adult ticks and nymphs had the MIR of 0.7%, while B. garinii was present in 1.1% of adults and showed a MIR of 0.1% in nymphs. The MLST of B. miyamotoi isolates showed that they belong to sequence type 635. No tick sample was positive after RT-qPCR for TBEV RNA.
CONCLUSIONS
The prevalence of B. miyamotoi in I. ricinus ticks registered similar levels to other reports from Europe suggesting that this agent might be well established in the local tick population. The detection of B. burgdorferi (s.l.) indicates a constant circulation in tick populations from this region.
Topics: Animals; Borrelia; Borrelia burgdorferi; Encephalitis Viruses, Tick-Borne; Female; Forests; Germany; Ixodes; Male; Multilocus Sequence Typing; Nymph; Real-Time Polymerase Chain Reaction; Ticks
PubMed: 32106890
DOI: 10.1186/s13071-020-3969-7 -
Ticks and Tick-borne Diseases Mar 2021Borrelia miyamotoi is an emerging pathogen that shares high similarity with relapsing fever Borrelia, but has an atypical clinical presentation. Within the framework of...
Borrelia miyamotoi is an emerging pathogen that shares high similarity with relapsing fever Borrelia, but has an atypical clinical presentation. Within the framework of tick-borne disease surveillance in Finland, human serum samples suspected for tick-borne encephalitis (n=974) and questing ticks (n=739) were collected from the capital region in Finland to determine the prevalence of B. miyamotoi. All tested human samples were negative and 5 (0.68 %) Ixodes ricinus ticks were positive for B. miyamotoi. Partial sequencing of the flagellin (flaB) gene of 3 positive samples and 27 B. miyamotoi-positive tick samples obtained from previous studies across Finland were amplified, sequenced, and included in the phylogenetic analysis. The phylogenetic tree revealed that most B. miyamotoi strains isolated from ticks in Finland share high similarity with other European strains, including strains related to human infection. Possible disease transmission may occur during exposure to tick bites. A single strain collected from an I. persulcatus tick in Pajujärvi grouped with an outlier of B. miyamotoi strains isolated from Russia and Far East Asian countries. Further studies should investigate the pathogen's role in human infection in Finland. Another important finding is the occurrence of I. persulcatus ticks (8%) collected by crowdsourcing from the coastal southern part of Finland. This suggests a regular introduction and a possible wide expansion of this tick species in the country. This could be associated with transmission of new pathogens.
Topics: Animals; Borrelia; Female; Finland; Ixodes; Phylogeny
PubMed: 33249364
DOI: 10.1016/j.ttbdis.2020.101608 -
Biologia 2022In Slovakia, 22 tick species have been found to occur to date. Among them, and marginally and have been identified as the species of public health relevance. Ticks in... (Review)
Review
In Slovakia, 22 tick species have been found to occur to date. Among them, and marginally and have been identified as the species of public health relevance. Ticks in Slovakia were found to harbour and transmit zoonotic and/or potentially zoonotic agents such as tick-borne encephalitis virus (TBEV), spirochaetes of the sensu lato (s.l.) complex, the relapsing fever sprirochaete , bacteria belonging to the orders Rickettsiales ( spp., , ), Legionellales () and Thiotrichales (), and spp. parasites (order Piroplasmida). is the principal vector of the largest variety of microorganisms including viruses, bacteria and piroplasms. TBEV, s.l., rickettsiae of the spotted fever group, and have been found to cause serious diseases in humans, whereas and pose lower or potential risk to humans Distribution of TBEV has a focal character. During the last few decades, new tick-borne encephalitis (TBE) foci and their spread to new areas have been registered and TBE incidence rates have increased. Moreover, Slovakia reports the highest rates of alimentary TBE infections among the European countries. Lyme borreliosis (LB) spirochaetes are spread throughout the distribution range of . Incidence rates of LB have shown a slightly increasing trend since 2010. Only a few sporadic cases of human rickettsiosis, anaplasmosis and babesiosis have been confirmed thus far in Slovakia. The latest large outbreaks of Q fever and tularaemia were recorded in 1993 and 1967, respectively. Since then, a few human cases of Q fever have been reported almost each year. Changes in the epidemiological characteristics and clinical forms of tularaemia have been observed during the last few decades. Global changes and development of modern molecular tools led to the discovery and identification of emerging or new tick-borne microorganisms and symbionts with unknown zoonotic potential. In this review, we provide a historical overview of research on ticks and tick-borne pathogens in Slovakia with the most important milestones and recent findings, and outline future directions in the investigation of ticks as ectoparasites and vectors of zoonotic agents and in the study of tick-borne diseases.
PubMed: 34548672
DOI: 10.1007/s11756-021-00845-3 -
Ugeskrift For Laeger May 2017The castor bean tick, Ixodes ricinus, is common in woodlands in most of Denmark. Besides Borrelia burgdorferi, it can harbour a number of pathogenic microorganisms such... (Review)
Review
The castor bean tick, Ixodes ricinus, is common in woodlands in most of Denmark. Besides Borrelia burgdorferi, it can harbour a number of pathogenic microorganisms such as tick-borne encephalitis virus, Anaplasma phagocytophilum, Rickettsia helvetica, Francisella tularensis, Candidatus Neoehrlichia mikurensis, Bartonella spp., Borrelia miyamotoi and Babesia spp. These tick-borne infections should be a differential diagnostic consideration during the tick season in Denmark. We review the distribution, clinical manifestations, diagnosis and treatment of these microorganisms.
Topics: Animals; Antiviral Agents; Denmark; Diagnosis, Differential; Humans; Ixodes; Tick Bites; Tick-Borne Diseases; Ticks
PubMed: 28504633
DOI: No ID Found -
Frontiers in Veterinary Science 2022Ticks transmit a broad spectrum of pathogens, threatening both animal and human health. Tick survival and proliferation are strongly dependent on host selection and...
Ticks transmit a broad spectrum of pathogens, threatening both animal and human health. Tick survival and proliferation are strongly dependent on host selection and suitability. The hard tick , which is widespread throughout most of Europe, is a host generalist capable of feeding on many different vertebrate species. Pasture-kept exotic farm animals may be at a high risk for tick and tick-borne pathogens infestations but research characterizing this is currently lacking. This study focused on the detection of spirochetes (including ) in exotic farm animals. Using nested-PCR with -specific primers, 121 serum samples from 54 exotic farm animals of several species bred in four different farms in Bohemia and Moravia (Czechia) were tested. Positive samples were sequenced for the identification of species. The prevalence of DNA in the samples ranged from 13 to 67%, depending on the sampling site. The sequencing results confirmed the DNA presence of multiple spirochete species from the sensu lato complex. Only one sample from an ostrich () was found to be positive for . The results show that exotic farm animals can serve as hosts for hard ticks and can be infected by spirochetes, transmitted by hard ticks. Therefore, these animals could play a relevant role in maintaining spirochetes in nature.
PubMed: 36246336
DOI: 10.3389/fvets.2022.996015