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In Europe, tick-borne diseases (TBDs) cause significant morbidity and mortality, affecting both human and animal health. Ticks can transmit a wide variety of pathogens (bacteria, viruses, and parasites) and feed on many vertebrate hosts. The incidence and public health burden of TBDs are tending to intensify in Europe due to various factors, mainly anthropogenic and often combined. Early detection of tick-borne pathogens (TBPs), preventive measures and treatment are of great importance to control TBDs and their expansion. However, there are various limitations in terms of the sensitivity and/or specificity of detection and prevention methods, and even in terms of feasibility. Aptamers are single-stranded DNA or RNA that could address these issues as they are able to bind with high affinity and specificity to a wide range of targets (e.g., proteins, small compounds, and cells) due to their unique three-dimensional structure. To date, aptamers have been selected against TBPs such as tick-borne encephalitis virus, Francisella tularensis , and Rickettsia typhi. These studies have demonstrated the benefits of aptamer-based assays for pathogen detection and medical diagnosis. In this review, we address the applications of aptamers to TBDs and discuss their potential for improving prevention measures (use of chemical acaricides, vaccination), diagnosis and therapeutic strategies to control TBDs. • The incidence of tick-borne diseases is increasing in Europe, with a major impact on human and animal health. • Their control is hampered by the lack of sensitive and specific detection and prevention tools. • Aptamers are promising tools, as they can bind with high affinity and specificity to their target. • This review compares aptamers with the current approach to tick-borne disease prevention and control. [ABSTRACT FROM AUTHOR]

Francisella tularensis is a zoonotic, gram‐negative bacterium that causes tularemia in humans. Depending on its subspecies and the route of transmission, mild to lethal courses have been reported. F. tularensis subsp. holarctica is the only subspecies found in Europe and affects a plenitude of vertebrates including lagomorphs and rodents. Population outbreaks of certain rodent species are likely to be involved in the transmission of this pathogen. This molecular survey aims to evaluate the presence of F. tularensis in small mammals from three Central European countries. Using a real‐time polymerase chain reaction, F. tularensis DNA was detected in common voles (Microtus arvalis) from Switzerland and in field voles (Microtus agrestis) and a bank vole (Myodes glareolus) from Germany, but not in any other small mammal species. All common voles from the Czech Republic were negative for F. tularensis DNA. The prevalence in the three vole species varied between 1.3% and 3.0%. In conclusion, Francisella tularensis DNA was detected in three vole species in two of three countries investigated. The observed low prevalence raises questions on the role of voles for the transmission of Francisella tularensis in Central Europe. [ABSTRACT FROM AUTHOR]

Tularaemia is a zoonotic disease caused by Francisella tularensis, a Gram-negative, facultative intracellular bacterium. Typically, human and animal infections are caused by F tularensis subspecies tularensis (type A) strains mainly in Canada and USA, and F tularensis subspecies holarctica (type B) strains throughout the northern hemisphere, including Europe. In the past, the epidemiological, clinical, therapeutic, and prognostic aspects of tularaemia reported in the English medical literature were mainly those that had been reported in the USA, where the disease was first described. Tularaemia has markedly changed in the past decade, and a large number of studies have provided novel data for the disease characteristics in Europe. In this Review we aim to emphasise the specific and variable aspects of tularaemia in different European countries. In particular, two natural lifecycles of F tularensis have been described in this continent, although not fully characterised, which are associated with different modes of transmission, clinical features, and public health burdens of tularaemia. [ABSTRACT FROM AUTHOR]

Tularemia outbreaks in humans have recently been reported in many European countries, but data on the occurrence in the animal population are scarce. In North America, seroconversion of omnivores and carnivores was used as indicator for the presence of tularemia, for the European fauna, however, data are barely available. Therefore, the suitability of wild boars ( Sus scrofa) and red foxes ( Vulpes vulpes) as indicators for the circulation of F. tularensis in Germany was evaluated. Serum samples from 566 wild boars and 457 red foxes were collected between 1995 and 2012 in three federal states in Central Germany (Hesse, Saxony-Anhalt, and Thuringia). The overall rate of seropositive animals was 1.1% in wild boars and 7.4% in red foxes. In conclusion, serological examination of red foxes is recommended, because they can be reliably used as indicator animals for the presence of F. tularensis in the environment. [ABSTRACT FROM AUTHOR]

Tularemia (caused by the facultative intracellular Gram-negative bacillus Francisella tularensis) is an endemic zoonotic disease in Europe, which exhibits different clinical patterns. Following the glandular form, pneumonia is the second most frequent manifestation in Switzerland. Pulmonary tularemia often has a subacute course and fails to respond to beta-lactam antibiotics. It can also mimic tuberculosis, because of the presence of systemic symptoms, such as fever, sweats and weight loss. History of animal exposure is not always reported. Clinicians should be aware of pulmonary tularemia. They should be able to diagnose it with appropriate tools (PCR, serology) and initiate appropriate therapy (fluoroquinolones, tetracyclines or aminoglycosides)., Competing Interests: Les auteurs n’ont déclaré aucun conflit d’intérêts en relation avec cet article.

Objectives Tularaemia is a widespread zoonosis in Europe caused by Francisella tularensis subsp. holarctica. Because of a lack of standardized CLSI-approved antibiotic susceptibility data from European Francisella strains, the antibiotic susceptibilities of a selection of F. tularensis subsp. holarctica isolates originating from Germany, Austria, France, Spain and other European countries were determined. Rarely isolated species and subspecies of Francisella such as Francisella philomiragia, F. tularensis subsp. novicida and F. tularensis subsp. mediasiatica as well as the type strain of Francisella hispaniensis were included in this study. Methods MIC data were obtained using cation-adjusted Mueller–Hinton broth with a 2% growth supplement. The broth microdilution testing system comprised 14 antibiotics, including gentamicin, streptomycin, ciprofloxacin and tetracycline. Results All of the 91 strains tested were susceptible to aminoglycosides, quinolones, tetracycline and chloramphenicol. The antimicrobial susceptibility of rare Francisellae was similar to the antibiotic profile of F. tularensis subsp. holarctica strains. For erythromycin, we detected two geographically distinct groups of F. tularensis subsp. holarctica isolates in western Europe. One group was resistant and the other one was susceptible. Both groups overlapped in a small region in Germany. Conclusions Being performed in accordance with CLSI criteria, this study provides reliable data on antibiotic susceptibility patterns of European Francisella isolates. The standardized methodology of this study can be used for testing of suspicious colonies from clinical specimens for therapeutic guidance. Based on the results, aminoglycosides or quinolones are recommended as first-choice antibiotics for the therapy of F. hispaniensis, F. philomiragia or F. tularensis subsp. novicida infections in immunocompromised patients. [ABSTRACT FROM PUBLISHER]

Abstract: Tularemia is a potentially fatal multi-systemic disease of humans and other animals caused by the bacterial pathogen Francisella tularensis. The disease can be transmitted by ticks, biting flies, water exposure, food, and aerosols and occurs around the northern hemisphere including North America, Europe, and Asia. There are several defined species and subspecies, including F. tularensis subsp. tularensis (Jellison Type A) which is pathogenic for rabbits and occurs in North America, F. tularensis subsp. holarctica (Type B) and mediaasiatica which are less pathogenic for rabbits, and F. tularensis subsp. novicida which has been regarded sometimes as the separate species F. novicida. Because it can have a high aerosol-related infection rate, low infectious dose, and ability to induce fatal disease, F. tularensis is considered a potential agent of biological warfare and is classified by the US Department of Health and Human Services as a List A select agent. We discuss microbiological, clinicopathological, epidemiological, and ecological aspects of tularemia. [Copyright &y& Elsevier]

Francisella tularensis can cause fatal respiratory tularemia in humans and animals and is increasingly being isolated in the United States and several European countries. The correlates of protective immunity against this intracellular bacterium are not known, and currently there are no licensed vaccines available for human use. Cell-mediated immunity has long been believed to be critical for protection, and the importance of humoral immunity is also now recognized. Furthermore, synergy between antibodies, T cell-derived cytokines, and phagocytes appears to be critical to achieve sterilizing immunity against F. tularensis. Thus, novel vaccine approaches should be designed to induce robust antibody and cell-mediated immune responses to this pathogen. [ABSTRACT FROM AUTHOR]

Tularaemia exists endemically in most European countries. In some areas, such as Finland and Sweden, outbreaks comprising hundreds of cases are recorded at least once a decade. In other areas, outbreaks of such a magnitude occur only occasionally, except in times of war. Between outbreaks, the natural reservoir of the causative agent, Francisella tularensis, is unknown. The organism replicates intracellularly in protozoans. An association of tularaemia to natural water may be of significance in locating the reservoir. Epidemiological work has to date been slow, but is now facilitated by the development of new molecular methods. Due to a variation in numbers of short sequence-tandem repeats in the bacterial genome, individual strains of F. tularensis can today be distinguished. [ABSTRACT FROM AUTHOR]

Introduction and Objective: Tularaemia is an infrequently occurring disease in Poland. It has therefore rarely been taken into account in the differential diagnosis of skin lesions, lymphadenitis, or soft tissue abscesses. This fact, accompanied by non-specific initial presentation, may lead to a delay in diagnosis and a more severe course of the disease. Objective. The aim of the study is to present the current state of knowledge on tularaemia and convince medical professionals to take it into consideration in the diagnosis of skin lesions, lymphadenitis, and tissue abscesses., Review Methods: A literature review using PubMed and other online resources, using terms including 'tularaemia', 'lymphadenitis', etc., was undertaken. Papers were reviewed for relevance and scientific merit., Abbreviated Description of the State of Knowledge: Tularaemia, also known as 'rabbit fever', is a zoonotic infection caused by Francisella tularensis, an aerobic, facultative intracellular, gram-negative bacteria. In Europe, it is mainly spread via tick bites and contact with wild animals such as lagomorphs and rodents. Clinical presentation may differ depending on the transmission route; the ulceroglandular and glandular forms of disease predominate. An early diagnosis and implementation of appropriate antibiotic therapy are the cornerstones of successful treatment and make it possible to avoid a surgical incision and drainage of suppurative complications., Summary: Raised awareness and knowledge on tularaemia among health care professionals are required for timely diagnosis and treatment. Arrival from endemic areas, contact with wild animals, tick bites, and exclusion of more common etiologies of presenting signs should prompt consideration of tularaemia. More research is needed for a better understanding of the burden of the disease and its impact on public health in Poland.

Francisella tularensis, a Gram-negative coccobacillus, is a highly virulent pathogen responsible for several zoonotic outbreaks in Europe in the last few decades. The authors report the case of a 46-year-old male who developed fever, myalgias and headache a week after having contact with animal feed contaminated by rodents. Serological tests were positive for Francisella tularensis. This first case of autochthonous tularemia in Portugal led to an intensive investigation involving several healthcare services and national governmental authorities. The authors address the possible underdiagnosis of this infection in the country.

In Europe, tularemia is caused by Francisella tularensis subsp. holarctica and is a sporadic disease affecting mainly wildlife animals and humans. Classification of this species relies on canonical single nucleotide polymorphisms (canSNPs). Four main clades have been described for F. tularensis subsp. holarctica: B.4, B.6, B.12 and B.16. Phylogeographic studies have shown that clade B.6 is predominant in Western Europe and B.12 in Eastern and Central Europe. Based on this global phylogeny, we aimed to design a molecular typing assay for all genetic subclades of subclade B.11, which is the predominant subclade in clade B.6. We designed high-resolution melting (HRM) primers for the screening of 109 canSNPs divided in seven orders of discrimination for the molecular epidemiology analysis and tracking of Francisella tularensis subsp. holarctica in Western Europe., (Copyright © 2021 Elsevier B.V. All rights reserved.)

We conducted a molecular analysis of Francisella tularensis strains isolated in Switzerland and identified a specific subpopulation belonging to a cluster of F. tularensis subsp. holarctica that is widely dispersed in central and western continental Europe. This subpopulation was present before the tularemia epidemics on the Iberian Peninsula. [ABSTRACT FROM AUTHOR]

Background: Tularemia, a zoonotic disease caused by Francisella tularensis, can cause a broad spectrum of disease in humans including six major clinical presentations: the ulceroglandular, glandular, oculoglandular, oropharyngeal, typhoidal and pneumonic form. The epidemiology and ecology and thus transmission of tularemia are complex, depending on conditions unique to specific locations., Case Series and Methods: Thirteen cases with different forms of the disease and one very rare case of a myocarditis are reported, discussed, and reviewed within the scope of current literature., Conclusion: Tularemia is a rare, but emerging disease in Central Europe with glandular and ulceroglandular disease as its predominant forms. Transmission is mainly caused by contact with lagomorphs, rodents and tick bites. However, domestic cats may play an important role in transmission too. Myocarditis is probably a worldwide, but very rare manifestation of tularemia.

We report the first two cases of infective endocarditis caused by Francisella tularensis in Europe (two cases have previously been reported outside Europe). We suggest clinicians should consider tularemia as a possible diagnosis in endemic regions in cases of culture-negative endocarditis.

For many infections transmitting to humans from reservoirs in nature, disease dispersal patterns over space and time are largely unknown. Here, a reversed genomics approach helped us understand disease dispersal and yielded insight into evolution and biological properties of Francisella tularensis , the bacterium causing tularemia. We whole-genome sequenced 67 strains and characterized by single-nucleotide polymorphism assays 138 strains, collected from individuals infected 1947-2012 across Western Europe. We used the data for phylogenetic, population genetic and geographical network analyses. All strains ( n =205) belonged to a monophyletic population of recent ancestry not found outside Western Europe. Most strains ( n =195) throughout the study area were assigned to a star-like phylogenetic pattern indicating that colonization of Western Europe occurred via clonal expansion. In the East of the study area, strains were more diverse, consistent with a founder population spreading from east to west. The relationship of genetic and geographic distance within the F. tularensis population was complex and indicated multiple long-distance dispersal events. Mutation rate estimates based on year of isolation indicated null rates; in outbreak hotspots only, there was a rate of 0.4 mutations/genome/year. Patterns of nucleotide substitution showed marked AT mutational bias suggestive of genetic drift. These results demonstrate that tularemia has moved from east to west in Europe and that F. tularensis has a biology characterized by long-range geographical dispersal events and mostly slow, but variable, replication rates. The results indicate that mutation-driven evolution, a resting survival phase, genetic drift and long-distance geographical dispersal events have interacted to generate genetic diversity within this species.

Background: Finland repeatedly reports some of the highest incidences of tularaemia worldwide. To determine genetic diversity of the aetiologic agent of tularaemia, Francisella tularensis, a total of 76 samples from humans (n = 15) and animals (n = 61) were analysed., Methods: We used CanSNPs and canINDEL hydrolysis or TaqMan MGB probes for the analyses, either directly from the clinical tissue samples (n = 21) or from bacterial isolates (n = 55)., Results: The genotypes of the strains were assigned to three previously described basal subspecies holarctica clades. The majority of strains (n = 67) were assigned to B.12, a clade reported to dominate in Scandinavia and Eastern Europe. A single strain was assigned to clade B.4, previously reported from North America, Europe and China. The remaining strains (n = 8) were members of clade B.6. Importantly, new diversity was discovered in clade B.6. We describe two newly designed TaqMan MGB probe assays for this new B.6 subclade B.70, and its previously identified sister clade B.11, a clade dominantly found in Western Europe., Conclusions: The high genetic diversity of F. tularensis subspecies holarctica present in Finland is consistent with previous findings in Sweden. The results suggest a northern and southern division of the B.6 subclade B.10, where B.11 predominates in Western and Central Europe and B.70 is found in Fennoscandia. Further research is required to define whether the vast diversity of genotypes found is related to different habitats or reservoir species, their different postglacial immigration routes to Fennoscandia, or dynamics of the reservoir species.

In recent years, several emerging zoonotic vector-borne infections with potential impact on human health have been identified in Europe, including tularaemia, caused by Francisella tularensis. This remarkable pathogen, one of the most virulent microorganisms currently known, has been detected in increasingly new settings and in a wide range of wild species, including lagomorphs, rodents, carnivores, fish and invertebrate arthropods. Also, a renewed concern has arisen with regard to F. tularensis: its potential use by bioterrorists. Based on the information published concerning the latest outbreaks, the aim of this paper is to review the main features of the agent, its biology, immunology and epidemiology. Moreover, special focus will be given to zoonotic aspects of the disease, as tularaemia outbreaks in human populations have been frequently associated with disease in animals., (Copyright © 2014 Elsevier Ltd. All rights reserved.)