Investigation of the ecology of Francisella tularensis during an inter-epizootic period

The geographic distribution, and the biotic and abiotic predictors of select zoonotic pathogen detections in Canadian polar bears

Increasing Arctic temperatures are facilitating the northward expansion of more southerly hosts, vectors, and pathogens, exposing naïve populations to pathogens not typical at northern latitudes. To understand such rapidly changing host-pathogen dynamics, we need sensitive and robust surveillance tools. Here, we use a novel multiplexed magnetic-capture and droplet digital PCR (ddPCR) tool to assess a sentinel Arctic species, the polar bear (Ursus maritimus; n = 68), for the presence of five zoonotic pathogens (Erysipelothrix rhusiopathiae, Francisella tularensis, Mycobacterium tuberculosis complex, Toxoplasma gondii and Trichinella spp.), and observe associations between pathogen presence and biotic and abiotic predictors. We made two novel detections: the first detection of a Mycobacterium tuberculosis complex member in Arctic wildlife and the first of E. rhusiopathiae in a polar bear. We found a prevalence of 37% for E. rhusiopathiae, 16% for F. tularensis, 29% for Mycobacterium tuberculosis complex, 18% for T. gondii, and 75% for Trichinella spp. We also identify associations with bear age (Trichinella spp.), harvest season (F. tularensis and MTBC), and human settlements (E. rhusiopathiae, F. tularensis, MTBC, and Trichinella spp.). We demonstrate that monitoring a sentinel species, the polar bear, could be a powerful tool in disease surveillance and highlight the need to better characterize pathogen distributions and diversity in the Arctic.

Water and mosquitoes as key components of the infective cycle of Francisella tularensis in Europe: a review

Francisella tularensis is the pathogen of tularemia, a zoonotic disease that have a broad range of hosts. Its epidemiology is related to aquatic environments, particularly in the subspecies holarctica. In this review, we explore the role of water and mosquitoes in the epidemiology of Francisella in Europe. F. tularensis epidemiology has been linked to natural waters, where its persistence has been associated with biofilm and amebas. In Sweden and Finland, the European countries where most human cases have been reported, mosquito bites are a main route of transmission. F. tularensis is present in other European countries, but to date positive mosquitoes have not been found. Biofilm and amebas are potential sources of Francisella for mosquito larvae, however, mosquito vector capacity has not been demonstrated experimentally, with the need to be studied using local species to uncover a potential transmission adaptation. Transstadial, for persistence through life stages, and mechanical transmission, suggesting contaminated media as a source for infection, have been studied experimentally for mosquitoes, but their natural occurrence needs to be evaluated. It is important to clear up the role of different local mosquito species in the epidemiology of F. tularensis and their importance in all areas where tularemia is present.

Rare Case of Tularemia With Preauricular Lymphadenopathy and Conjunctivitis in a 27-Year-Old Male Patient in Germany

Tularemia is a rare disease but shows an approximately 10-fold increase in reported cases over the last 15 years in Germany. Clinical symptoms of acute tularemia infection are various, which often delays diagnosis. This case report gives an overview of the clinical manifestations of acute tularemia and shows the importance of interdisciplinary work to shorten the time from the onset of symptoms to effective treatment in infection with Francisella tularensis. Since some cases of tularemia are life-threatening, early diagnosis is vital. This case report serves as a reminder that rare diseases need to be considered in cervical lymphadenopathy.

Francisella tularensis PCR detection in Cape hares (Lepus capensis) and wild rabbits (Oryctolagus cuniculus) in Algeria

Tularemia is a zoonosis caused by the bacterium Francisella tularensis. Leporids are primary sources of human infections in the northern hemisphere. Africa is classically considered free of tularemia, but recent data indicate that this dogma might be wrong. We assessed the presence of this disease in wild leporids in Algeria. Between 2014 and 2018, we collected 74 leporids carcasses from spontaneously dead or hunted animals. Francisella tularensis DNA was detected by specific real-time PCR tests in 7/36 (19.44%) Cape hares (Lepus capensis) and 5/38 (13.15%) wild rabbits (Oryctolagus cuniculus). Known tularemia arthropod vectors infested half of the PCR-positive animals. At necropsy, F. tularensis-infected animals presented with an enlarged spleen (n = 12), enlarged adrenal glands (12), liver discoloration (12), hemorrhages (11), and pneumonia (11). Immunohistological examination of liver tissue from one animal was compatible with the presence of F. tularensis. Our study demonstrates the existence of tularemia in lagomorphs in Algeria. It should encourage investigations to detect this disease among the human population of this country.

Complicated ulceroglandular tularemia

A 52-year-old woman presented with a tender swelling in the right axilla, fever, a headache, nausea, and general weakness. On examination, she was found to have lymphangitis on the right arm and red papules on the 1^st and 2^nd fingers of the right hand. She had had prepared wild rabbit stew 5 days before disease onset. Serology and an ultrasound of the right axilla confirmed the diagnosis of ulceroglandular tularemia. The lymphadenitis did not resolve after streptomycin treatment so an incision was made and 30 cc of purulent fluid drained. Over the course of the next 3 months, the fluid continued to drain. A radiographic fistulography was performed and it revealed a short main channel with a few long channels of varying caliber branching out from it, all terminating in a conglomerate of necrotic axillary lymph nodes. The lesions healed spontaneously and completely over the following 12 months without additional antibiotic therapy. Radiographic fistulography can help plot the course of the fistula/fistulas and demonstrate the anatomic features of the lesion in resource poor settings.

Francisella tularensis human infections in a village of northwest Iran

Background

Recent seroepidemiological studies have suggested that tularemia could be an endemic bacterial zoonosis in Iran.

Methods

From January 2016 to June 2018, disease cases characterized by fever, cervical lymphadenopathy and ocular involvement were reported in Youzband Village of Kaleybar County, in the East Azerbaijan Province, northwestern Iran. Diagnostic tests included Francisella tularensis serology (including tube agglutination test and ELISA), PCR, and culture.

Results

Among 11 examined case-patients, the tularemia tube agglutination test was positive in ten and borderline in one. PCR detected the F. tularensisISFtu2 elements and fopA gene in one rodent and a spring water sample from the same geographic area.

Conclusions

Based on the clinical manifestations of the disease suggesting an oropharyngeal form of tularemia, serology results in case patients, and F. tularensis detection in the local fauna and aquatic environment, the water supply of the village was the likely source of the tularemia outbreak. Intervention such as dredging and chlorination of the main water storage tank of the village and training of villagers and health care workers in preventive measures and treatment of the illness helped control the infection.

Characterization of Tularemia Cases in Slovenia with Multiple-Locus Variable-Number Tandem Repeat Analysis

Francisella tularensis is the etiologic agent of tularemia, a bacterial zoonotic disease. The genome of F. tularensis shows a recent evolutionary change, especially in reservoirs. Variable number of tandem repeats (VNTR) is described as a high-speed molecular clock and can thus be used as a high-resolution typing system. The main objective of our study was to investigate the molecular diversity of F. tularensis strains and reveal possible sources of infection. Using real-time PCR targeting the ISFtu2 region, we successfully amplified targeted DNA in 13/31 Slovenian patients with a clinical diagnosis of tularemia, and with PCR targeting the fopA gene, we obtained 11/13 PCR products. Sequencing revealed that all samples were identified as F. tularensis subsp. holarctica. We successfully obtained one F. tularensis isolate from a lymph node aspirate by culture on chocolate agar. Our isolate was clustered into major clade B12 (subclade B43). We optimized VNTR typing to be used directly on clinical samples. Multiple-locus VNTR analysis (MLVA) revealed five unique MLVA types; 45.5% samples had the same MLVA type, another 27.3% shared a different MLVA type, and each of the remaining had a unique MLVA type. Most samples differed at only two VNTR markers (Ft-M03 and Ft-M06). Additionally, we investigated samples from small mammals (n = 532) and Ixodes ricinus ticks (n = 232) captured in the same geographical area in which patients with tularemia were found. No F. tularensis DNA was detected in samples of small mammals or I. ricinus ticks. The diversity of MLVA types in Slovenia was high, despite the small region, but most of the samples from the same region shared the same MLVA type. Our results suggest that MLVA is a useful tool for quick molecular characterization of F. tularensis directly from patient samples, especially when investigating geographically localized outbreaks.

Francisella tularensis survey among ranchers and livestock in western Iran

Tularemia is a zoonotic disease that transmitted to humans and domestic animals by wildlife, especially rodents. There are some evidences of the circulation of F. tularensis in rodents, livestock, human populations, and surface waters in western parts of Iran. In this study, we investigated the exposure of livestock and ranchers to F. tularensis in the endemic regions of western Iran. Blood samples were collected from 289 sheep, 103 cattle, and 51 ranchers in 2018. Animal sera were tested by standard tube agglutination method. The specific IgGs against F. tularensis were evaluated by ELISA in human sera. Moreover, the extracted DNAs from 50 sheep spleen samples were evaluated using TaqMan real-time PCR for the presence of ISFtu2 and FopA genes. All animal sera and spleen samples were negative for tularemia. Of the 51 human samples, two samples were seropositive and one sample showed a borderline status for tularemia. Serologic evidence of F. tularensis in the ranchers but negative results in the livestock indicates different transmission routes in human populations and domestic animals in western Iran. Therefore, drinking contaminated water, contact to wildlife or rodents and arthropod bite should be considered as probable routes in the suspicious areas.

Tularemia Goes West: Epidemiology of an Emerging Infection in Austria

The zoonotic disease tularemia is caused by the Gram-negative bacterium Francisella tularensis, with the two major subspecies tularensis and holarctica being responsible for infections in humans and animals. The F. tularensis subspecies holarctica is less virulent and prevalent in Europe and Asia. Over the last few centuries, few epidemic outbreaks and low numbers of infections have been registered in the eastern part of Austria, specifically in the provinces of Lower Austria, Burgenland, and Styria. The reported infections were mostly associated with hunting hares and the skinning of carcasses. Within the last decade, ticks have been identified as important vectors in Tyrol and served as first evidence for the spread of F. tularensis to Western Austria. In 2018, the pathogen was detected in hares in the provinces of Tyrol, Vorarlberg, and Salzburg. We presume that F. tularensis is now established in most regions of Austria, and that the investigation of potential host and vector animals should be spotlighted by public institutions. Tularemia in humans presents with various clinical manifestations. As glandular, ulceroglandular, and typhoidal forms occur in Austria, this infectious disease should be considered as a differential diagnosis of unknown fever.

Francisella tularensis Subspecies holarctica and Tularemia in Germany

Tularemia is a zoonotic disease caused by Francisella tularensis a small, pleomorphic, facultative intracellular bacterium. In Europe, infections in animals and humans are caused mainly by Francisella tularensis subspecies holarctica. Humans can be exposed to the pathogen directly and indirectly through contact with sick animals, carcasses, mosquitoes and ticks, environmental sources such as contaminated water or soil, and food. So far, F. tularensis subsp. holarctica is the only Francisella species known to cause tularemia in Germany. On the basis of surveillance data, outbreak investigations, and literature, we review herein the epidemiological situation-noteworthy clinical cases next to genetic diversity of F. tularensis subsp. holarctica strains isolated from patients. In the last 15 years, the yearly number of notified cases of tularemia has increased steadily in Germany, suggesting that the disease is re-emerging. By sequencing F. tularensis subsp. holarctica genomes, knowledge has been added to recent findings, completing the picture of genotypic diversity and geographical segregation of Francisella clades in Germany. Here, we also shortly summarize the current knowledge about a new Francisella species (Francisella sp. strain W12-1067) that has been recently identified in Germany. This species is the second Francisella species discovered in Germany.

Molecular identification of the source of an uncommon tularaemia outbreak, Germany, autumn 2016

Background

In 2016, an uncommon outbreak of oropharyngeal tularaemia involving six human cases occurred in Germany, caused by drinking contaminated fresh must after a grape harvest.

Aim

We describe the details of laboratory investigations leading to identification of the outbreak strain, its characterisation by next generation sequencing (NGS) and the finding of the possible source of contamination.

Methods

We incubated wine samples in different media and on agar plates. NGS was performed on DNA isolated from young wine, sweet reserve and an outbreak case’s lymph node. A draft genome of the outbreak strain was generated. Vertebrate-specific PCRs using primers targeting the mitochondrial cytochrome b gene and product analyses by blast search were used to identify the putative source of must contamination.

Results

No bacterial isolate could be obtained. Analysis of the draft genome sequence obtained from the sweet reserve attributed this sequence to Francisella tularensis subsp. holarctica, belonging to the B.12/B.34 phylogenetic clade (erythromycin-resistant biovar II). In addition, the DNA sequence obtained from the case’s isolate supported our hypothesis that infection was caused by drinking contaminated must. The vertebrate-specific cytochrome b sequence derived from the young wine and the sweet reserve could be assigned to Apodemus sylvaticus (wood mouse), suggesting that a wood mouse infected with F. tularensis may have contaminated the must.

Conclusion

The discovered source of infection and the transmission scenario of F. tularensis in this outbreak have not been observed previously and suggest the need for additional hygienic precautionary measures when processing and consuming freshly pressed must.

First record of Haemaphysalis concinna (Acari: Ixodidae) in Lithuania

The relict tick Haemaphysalis concinna Koch, 1844 (Acari: Ixodidae) has high medical and veterinary importance as it is known as a vector or a carrier of various pathogens causing human and animal diseases. Haemaphysalis concinna is a widely distributed species in forests of temperate Eurasia. In Europe, it is found mainly in deciduous or mixed forests near shores of lakes or rivers. However, there is still a lack of knowledge about current distribution, relative density, and other ecological parameters of H. concinna. On June 30th, 2019, one specimen of H. concinna was found on the fur of a hunted roe deer in Lithuania. This is the first record of H. concinna in Lithuania and, to the best of our knowledge, it represents the northernmost distribution point of H. concinna in Europe (22°55'26.5"E/ 55°27'50.7"N).

Checklist of the hard tick (Acari: Ixodidae) fauna of Hungary with emphasis on host-associations and the emergence of Rhipicephalus sanguineus

Hungary is situated in the southern part of Central Europe, next to the northern boundary of the Mediterranean region. This geographical position may allow the northward expansion of Mediterranean ixodid tick species into Hungary, particularly in the era of warming climate. During the past 14 years numerous surveys have been published on the species and activity of hard ticks occurring in the country. However, it was 60 years ago that the last comprehensive review of ixodid ticks of Hungary was published, and only in Hungarian language. The purpose of the present checklist is to provide a comprehensive and complete overview of the ixodid fauna of Hungary, based on tick reports published so far in Hungarian or English, also including hitherto unpublished data. Altogether 27 hard tick species were identified in Hungary, of which 21 can be regarded as indigenous. Most importantly, the autochthonous occurrence of Rhipicephalus sanguineus sensu lato was not known prior to 2005, but during the last 14 years increasing numbers of cases have been reported, attesting the emergence of this tick species in Hungary. Whereas R. sanguineus sensu lato was always associated with dogs and cats in Hungary, other tick species show differences in host associations according to habitat type, seasonal activity and questing height. Changes in the distribution, abundance and seasonality of a few tick species were also noted.

European Brown hare (Lepus europaeus) as a source of emerging and re-emerging pathogens of Public Health importance: A review

European brown hare (Lepus europaeus, EBH) is probably the most important game animal in Europe throughout its historical distribution. The decline in its populations across its geographic range in Europe have been attributed to factors such as reproductive rate and the ability for adaptation, climate, feed availability, predators, anthropogenic factors and diseases. Apart from common diseases of hares with a high impact on their mortality such as European Brown hare Syndrome, EBH has been involved in the epidemiology of pathogens with zoonotic potential. In this work, the role of EBH as a source of Crimean–Congo haemorrhagic fever virus (CCHFV), Hepatitis E virus (HEV), Yersinia spp., Brucella spp., Francisella tularensis, Toxoplasma gondii and Leishmania infantum is discussed. Hares may significantly contribute to the epidemiology of important emerging zoonotic pathogens through maintenance of high endemicity levels as in the case of CCHFV, as a reservoir of important pathogens such as Yersinia spp., B. suis, F. tularensis and L. infantum and as a potential source of T. gondii for other animals, especially for carnivores but also for humans. However, EBH may also be a host of minor importance as in the case of HEV. The continuous surveillance of hare populations will enable the collection of information on the population health status and the pathogens currently circulating in the area posing risk for wildlife, domestic animals and humans. The possible live animal translocations of infected hares, the fact that this species acts as a host of vectors (fleas, ticks, mosquitoes and sandflies) and the prey of carnivores and omnivores that travel in great distances getting into contact with domestic animals and humans, further highlights the need to be included in surveillance studies. Besides, the hunter‐harvested EBH population is an excellent indicator for recent pathogen transmission due to its short lifespan.

The present review provides an overview of the role of European Brown Hare as a source of Crimean–Congo haemorrhagic fever virus (CCHFV), Hepatitis E virus (HEV), Yersinia spp., Brucella spp., Francisella tularensis, Toxoplasma gondii and Leishmania infantum aiming to highlight the contribution of this species to the epidemiology of important emerging zoonotic pathogens.

Surveillance of Francisella tularensis in surface water of Kurdistan province, west of Iran

BACKGROUND

The etiologic agent of tularemia, Francisella tularensis, is transmitted to humans via ingestion of contaminated water or food, arthropods bite, respiratory aerosols, or direct contact with infected animals body fluids or tissues. In the current study, due to the importance of water in transmitting the disease and the report of the disease in different regions of Iran, surface water of Kurdistan province were evaluated for the presence of F.tularensis.

MATERIALS AND METHODS

Sampling was carried out in five-counties of Kurdistan province. Sixty-six specimens of surface water were collected. The detection was carried out by targeting ISFtu2 and fopA genes using TaqMan real-time PCR. Moreover, the samples were both cultured and inoculated into NMRI inbreed mice. Spleens of inoculated mice and bacterial isolates were tested by TaqMan real-time PCR.

RESULTS

Despite the lack of isolation of F. tularensis, the results of the molecular testing indicate the presence of bacteria in surface water. Molecular positivity of one sample (1.51%) was confirmed using a real-time PCR for both ISFtu2 and fopA genes. Moreover, 4.54% of the samples were positive for ISFtu2.

CONCLUSION

Since the in vitro isolation of bacteria from environmental samples is associated with a very low success rate and depends on various environmental parameters, the use of molecular techniques for monitoring of the bacteria in the contaminated areas is fully recommended.

Investigation of the Role of the European Brown Hare in the Epidemiology of Bacterial Zoonotic Pathogens: A Serological and Molecular Survey in Greece

The aim of this study was to investigate the occurrence of Bartonella spp, Brucella spp, Coxiella burnetii, and Francisella tularensis in European Brown hares (Lepus europaeus) hunter harvested during 2-year hunting periods in northern and central Greece. Serum samples were examined for the presence of IgG antibodies by using an immune fluorescence test and/or an enzyme-linked immunosorbent assay. PCR was used to detect Bartonella spp DNA in blood samples and Brucella spp, C. burnetii, and F. tularensis DNA in liver samples. Antibodies against Bartonella spp were detected in 12 hares (12/105); whereas none of the hares examined was seropositive for Brucella spp, C. burnetii, and F. tularensis. The presence of Bartonella spp, Brucella spp, C. burnetii, and F. tularensis DNA was not detected in the samples examined. This study did not provide any evidence that the European Brown hare is involved in the epidemiology of Brucella spp, C. burnetii, and F. tularensis in Greece. However, our results suggest that this species is exposed to Bartonella spp, which gives the impetus for further investigation of its role as another host of this bacterium.

A serological and molecular study on Francisella tularensis in rodents from Hamadan province, Western Iran

INTRODUCTION AND PURPOSE

Tularemia is a zoonotic disease, the most important hosts of which are rodents. Endemic regions and reservoirs of F. tularensis are not well-researched areas in Iran. The present study aimed to study F. tularensis infection in the rodent populations of western Iran.

MATERIALS AND METHODS

Samples were collected in different areas of Kabudar Ahang County in Hamadan province (west of Iran) from 2014 to 2017. Tularemia serological and molecular tests were conducted using the tube agglutination test and Real-time PCR method tracking the ISFtu2 gene. Positive serum samples were evaluated for cross-reactivity with brucellosis.

RESULTS

A total of 433 rodents, collected from 33 localities, were included in the study. The most abundant species belonged to the Persian jird (Meriones persicus; 75.5%), and Libyan jird (Meriones libycus; 10.1%). Among the studied samples, three (0.74 %) were seropositive and five (1.15%) were PCR positive. Seropositive samples were two M. persicus and one M. libycus, and PCR positive rodents were four M. persicus and one M. vinogradovi. Tularemia seropositive samples showed no cross-reactivity with brucellosis.

CONCLUSION

Given the presence of infection in rodents with tularemia agent in the studied area, it is crucial to elucidate the risks of rodent exposure to tularemia for physicians, health personnel and the general population.

Borrelia and Other Zoonotic Pathogens in Ixodes ricinus and Dermacentor reticulatus Ticks Collected from the Chernobyl Exclusion Zone on the 30th Anniversary of the Nuclear Disaster

Background: The 26th of April 2016 marked 30 years since the Chernobyl accident has occurred in Ukraine. As a result, the uninhabited Chernobyl region has been directly exposed to ionizing radiation for >30 years. Most work has focused on identifying associations between levels of radiation and the abundance, distribution, and mutation rates of plants and animals. Much less, however, is known about microbial communities in this affected region. To date, there are no reports on the prevalence of any tick-borne pathogens in Ixodes ricinus ticks from the Chernobyl exclusion zone (CEZ). The objective of our study was to examine the abundance of I. ricinus and Dermacentor reticulatus ticks in the CEZ and to investigate the prevalence of Borrelia burgdorferi sensu lato (s.l.) and other zoonotic agents in these ixodid ticks. Methods: A total of 260 questing I. ricinus and 100 D. reticulatus adult ticks were individually polymerase chain reaction analyzed for the presence of Anaplasma phagocytophilum, Babesia spp., Bartonella spp., Borrelia burgdorferi s.l., Francisella tularensis, and/or Rickettsia spp. Results: The respective infections rates were identified and compared with those of ixodid ticks that were concurrently collected from Kyiv. The significant differences between the infection rates of the CEZ and Kyiv ticks were observed for Rickettsia raoultii in D. reticulatus ticks (53.0% vs. 35.7%, respectively; p < 0.05) and Bartonella spp. (8.1% vs. 2.7%; P < 0.05) in I. ricinus ticks. Conclusions: Although the current data clearly demonstrated that the prevalence of some zoonotic pathogens were significantly higher in the ixodid ticks from the CEZ, a more comprehensive systematic approach is required to examine the causal effect of long-term ionizing radiation on adaptive changes of tick-borne pathogens.

Tularemia as a waterborne disease: a review

Francisella tularensis is a Gram-negative, intracellular bacterium causing the zoonosis tularemia. This highly infectious microorganism is considered a potential biological threat agent. Humans are usually infected through direct contact with the animal reservoir and tick bites. However, tularemia cases also occur after contact with a contaminated hydro-telluric environment. Water-borne tularemia outbreaks and sporadic cases have occurred worldwide in the last decades, with specific clinical and epidemiological traits. These infections represent a major public health and military challenge. Human contaminations have occurred through consumption or use of F. tularensis-contaminated water, and various aquatic activities such as swimming, canyoning and fishing. In addition, in Sweden and Finland, mosquitoes are primary vectors of tularemia due to infection of mosquito larvae in contaminated aquatic environments. The mechanisms of F. tularensis survival in water may include the formation of biofilms, interactions with free-living amoebae, and the transition to a 'viable but nonculturable' state, but the relative contribution of these possible mechanisms remains unknown. Many new aquatic species of Francisella have been characterized in recent years. F. tularensis likely shares with these species an ability of long-term survival in the aquatic environment, which has to be considered in terms of tularemia surveillance and control.

Tularemia transmission to humans: a multifaceted surveillance approach

Tularemia has sustained seroprevalence in Eurasia, with estimates as high as 15% in endemic regions. The purpose of this report is to characterise the current epidemiology of Francisella tularensis subspecies holarctica in Georgia. Three surveillance activities are summarised: (1) acute infections captured in Georgia's notifiable disease surveillance system, (2) infectious disease seroprevalence study of military volunteers, and (3) a study of seroprevalence and risk factors in endemic regions. Descriptive analyses of demographic, exposure and clinical factors were conducted for the surveillance studies; bivariate analyses were computed to identify risk factors of seropositivity using likelihood ratio χ2 tests or Fisher's exact tests. Of the 19 incident cases reported between 2014 and August 2017, 10 were confirmed and nine met the presumptive definition; the estimated annual incidence was 0.12/100 000. The first cases of tularemia in Western Georgia were reported. Seroprevalences of antibodies for F. tularensis were 2.0% for military volunteers and 5.0% for residents in endemic regions. Exposures correlated with seropositivity included work with hay and contact with multiple types of animals. Seroprevalence studies conducted periodically may enhance our understanding of tularemia in countries with dramatically underestimated incidence rates.

Newly emerging ulceroglandular tularaemia in Western Austria

Tularaemia is a rare zoonotic disease caused by Francisella tularensis in humans. In Europe infections of humans and animals are mainly caused by F. tularensis subspecies holarctica. We report the first three documented cases of tularaemia in humans in Western Austria.

Geographical distribution, climate adaptation and vector competence of the Eurasian hard tick Haemaphysalis concinna

The ixodid tick Haemaphysalis concinna Koch, 1844 is a proven vector of tick-borne encephalitis (TBE) virus and Francisella tularensis, the causative agent of tularaemia. In the present study, up-to-date maps depicting the geographical distribution and climate adaptation of H. concinna are presented. A dataset was compiled, resulting in 656 georeferenced locations in Eurasia. The distribution of H. concinna ranges from the Spanish Atlantic coast to Kamchatka, Russia, within the belt of 28-64° N latitude. H. concinna is the second most abundant tick species after Ixodes ricinus collected from birds, and third most abundant tick species flagged from vegetation in Central Europe. To investigate the climate adaptation of H. concinna, the georeferenced locations were superimposed on a high-resolution map of the Köppen-Geiger climate classification. A frequency distribution of the H. concinna occurrence under different climates shows three peaks related to the following climates: warm temperate with precipitation all year round, boreal with precipitation all year round and boreal, winter dry. Almost 87.3 % of all H. concinna locations collected are related to these climates. Thus, H. concinna prefers climates with a warm and moist summer. The remaining tick locations were characterized as cold steppes (6.2%), cold deserts (0.8%), Mediterranean climates (2.7%) or warm temperate climates with dry winter (2.9%). In those latter climates H. concinna occurs only sporadically, provided the microclimate is favourable. Beyond proven vector competence pathogen findings in questing H. concinna are compiled from the literature.

Tularemia in Germany-A Re-emerging Zoonosis

Tularemia, also known as “rabbit fever,” is a zoonosis caused by the facultative intracellular, gram-negative bacterium Francisella tularensis. Infection occurs through contact with infected animals (often hares), arthropod vectors (such as ticks or deer flies), inhalation of contaminated dust or through contaminated food and water. In this review, we would like to provide an overview of the current epidemiological situation in Germany using published studies and case reports, an analysis of recent surveillance data and our own experience from the laboratory diagnostics, and investigation of cases. While in Germany tularemia is a rarely reported disease, there is evidence of recent re-emergence. We also describe some peculiarities that were observed in Germany, such as a broad genetic diversity, and a recently discovered new genus of Francisella and protracted or severe clinical courses of infections with the subspecies holarctica. Because tularemia is a zoonosis, we also touch upon the situation in the animal reservoir and one-health aspects of this disease. Apparently, many pieces of the puzzle need to be found and put into place before the complex interaction between wildlife, the environment and humans are fully understood. Funding for investigations into rare diseases is scarce. Therefore, combining efforts in several countries in the framework of international projects may be necessary to advance further our understanding of this serious but also scientifically interesting disease.

Seroprevalence of Francisella tularensis in Austrian Hunting Dogs

Based on initial reports of infection with Francisella tularensis in dogs in northern Europe, a serological study in hunting dogs was conducted in Austria. Five (6.25%) tested positive. The results highlight the potential for disease transmission to dogs and raise the question of whether dogs could be a source of infection for humans.

Abiotic and Biotic Contributors to Support Inter-Epidemic Francisella tularensis in an Agricultural Peri-Urban Environment

To characterize the inter-epidemic ecology of Francisella tularensis, we surveyed vertebrates and invertebrates for the abundance, spatial distribution, and status of infection at a site in northern California that had evidence of endemic type B tularemia. We collected 2910 mosquitoes, 77 biting flies, 704 ticks, 115 mammals, and 1911 aquatic invertebrates in 2013-2014. Real-time PCR on all mosquitoes, 40 biting flies, 113 aquatic invertebrates, and 650 ticks did not detect F. tularensis DNA. Indirect enzyme linked immunosorbent assay (ELISA) on 109 mammals revealed 2 (of 2, 100%) seropositive feral cats, 1 (of 24, 4.5%) seropositive black rat, and 5 (of 10, 50%) seropositive Virginia opossums. A riparian reserve, ∼1 km from the primate research center, had the highest seroprevalence in mammals and the highest capture success for invertebrate vectors whereas opossums, cats, and ground squirrels in close proximity to the primate center had high seroprevalence and abundant fleas. Well-vegetated regions with standing water appeared to be ideal habitats for biotic components of tularemia enzootic persistence. Mesocarnivores may facilitate the spread of F. tularensis, and high densities of rodents and their fleas may be a mechanism for amplification and spillover.

Flavivirus Infection of Ixodes scapularis (Black-Legged Tick) Ex Vivo Organotypic Cultures and Applications for Disease Control

Ixodes scapularis ticks transmit many infectious agents that cause disease, including tick-borne flaviviruses (TBFVs). TBFV infections cause thousands of human encephalitis cases worldwide annually. In the United States, human TBFV infections with Powassan virus (POWV) are increasing and have a fatality rate of 10 to 30%. Additionally, Langat virus (LGTV) is a TBFV of low neurovirulence and is used as a model TBFV. TBFV replication and dissemination within I. scapularis organs are poorly characterized, and a deeper understanding of virus biology in this vector may inform effective countermeasures to reduce TBFV transmission. Here, we describe short-term, I. scapularis organ culture models of TBFV infection. Ex vivo organs were metabolically active for 9 to 10 days and were permissive to LGTV and POWV replication. Imaging and videography demonstrated replication and spread of green fluorescent protein-expressing LGTV in the organs. Immunohistochemical staining confirmed LGTV envelope and POWV protein synthesis within the infected organs. LGTV- and POWV-infected organs produced infectious LGTV and POWV; thus, the ex vivo cultures were suitable for study of virus replication in individual organs. LGTV- and POWV-infected midgut and salivary glands were subjected to double-stranded RNA (dsRNA) transfection with dsRNA to the LGTV 3' untranslated region (UTR), which reduced infectious LGTV and POWV replication, providing a proof-of-concept use of RNA interference in I. scapularis organ cultures to study the effects on TBFV replication. The results contribute important information on TBFV localization within ex vivo I. scapularis organs and provide a significant translational tool for evaluating recombinant, live vaccine candidates and potential tick transcripts and proteins for possible therapeutic use and vaccine development to reduce TBFV transmission.IMPORTANCE Tick-borne flavivirus (TBFV) infections cause neurological and/or hemorrhagic disease in humans worldwide. There are currently no licensed therapeutics or vaccines against Powassan virus (POWV), the only TBFV known to circulate in North America. Evaluating tick vector targets for antitick vaccines directed at reducing TBFV infection within the arthropod vector is a critical step in identifying efficient approaches to controlling TBFV transmission. This study characterized infection of female Ixodes scapularis tick organ cultures of midgut, salivary glands, and synganglion with the low-neurovirulence Langat virus (LGTV) and the more pathogenic POWV. Cell types of specific organs were susceptible to TBFV infection, and a difference in LGTV and POWV replication was noted in TBFV-infected organs. This tick organ culture model of TBFV infection will be useful for various applications, such as screening of tick endogenous dsRNA corresponding to potential control targets within midgut and salivary glands to confirm restriction of TBFV infection.

Quantifying the Availability of Vertebrate Hosts to Ticks: A Camera-Trapping Approach

The availability of vertebrate hosts is a major determinant of the occurrence of ticks and tick-borne zoonoses in natural and anthropogenic ecosystems and thus drives disease risk for wildlife, livestock, and humans. However, it remains challenging to quantify the availability of vertebrate hosts in field settings, particularly for medium-sized to large-bodied mammals. Here, we present a method that uses camera traps to quantify the availability of warm-bodied vertebrates to ticks. The approach is to deploy camera traps at questing height at a representative sample of random points across the study area, measure the average photographic capture rate for vertebrate species, and then correct these rates for the effective detection distance. The resulting "passage rate" is a standardized measure of the frequency at which vertebrates approach questing ticks, which we show is proportional to contact rate. A field test across twenty 1-ha forest plots in the Netherlands indicated that this method effectively captures differences in wildlife assemblage composition between sites. Also, the relative abundances of three life stages of the sheep tick Ixodes ricinus from drag sampling were correlated with passage rates of deer, which agrees with the known association with this group of host species, suggesting that passage rate effectively reflects the availability of medium- to large-sized hosts to ticks. This method will facilitate quantitative studies of the relationship between densities of questing ticks and the availability of different vertebrate species-wild as well as domesticated species-in natural and anthropogenic settings.

Francisella tularensis Susceptibility to Antibiotics: A Comprehensive Review of the Data Obtained In vitro and in Animal Models

The antibiotic classes that are recommended for tularaemia treatment are the aminoglycosides, the fluoroquinolones and the tetracyclines. However, cure rates vary between 60 and 100% depending on the antibiotic used, the time to appropriate antibiotic therapy setup and its duration, and the presence of complications, such as lymph node suppuration. Thus, antibiotic susceptibility testing (AST) of F. tularensis strains remains of primary importance for detection of the emergence of antibiotic resistances to first-line drugs, and to test new therapeutic alternatives. However, the AST methods reported in the literature were poorly standardized between studies and AST data have not been previously evaluated in a comprehensive and comparative way. The aim of the present review was to summarize experimental data on antibiotic susceptibilities of F. tularensis obtained in acellular media, cell models and animal models since the introduction of fluoroquinolones in the treatment of tularaemia in 1989. We compiled MIC data of 33 antibiotics (including aminoglycosides, fluoroquinolones, tetracyclines, macrolides, β-lactams, chloramphenicol, rifampicin, and linezolid) against 900 F. tularensis strains (504 human strains), including 107 subsp. tularensis (type A), 789 subsp. holarctica (type B) and four subsp. mediasiatica strains, using various AST methods. Specific culture media were identified or confirmed as unsuitable for AST of F. tularensis. Overall, MICs were the lowest for ciprofloxacin (≤ 0.002-0.125 mg/L) and levofloxacin, and ranged from ≤ 0.016 to 2 mg/L for gentamicin, and 0.064 to 4 mg/L for doxycycline. No resistant strain to any of these antibiotics was reported. Fluoroquinolones also exhibited a bactericidal activity against intracellular F. tularensis and lower relapse rates in animal models when compared with the bacteriostatic compound doxycycline. As expected, lower MIC values were found for macrolides against type A and biovar I type B strains, compared to biovar II type B strains. The macrolides were more effective against F. tularensis grown in phagocytic cells than in acellular media.

A Field Study of Plague and Tularemia in Rodents, Western Iran

INTRODUCTION

Kurdistan Province in Iran is a historical focus for plague and tularemia. This study aimed at assessing the current status of these two foci by studying their rodent reservoirs.

MATERIALS AND METHODS

Rodents were trapped and their ectoparasites were collected. The genus and species of both rodents and ectoparasites were determined. Serological analyses of rodent blood samples were done by enzyme-linked immunosorbent assay for plague and by standard tube agglutination assay for tularemia. Rodent spleen samples were subjected to bacterial culture, microscopic examination, and real-time PCR to search for active plague or tularemia infection.

RESULTS

During this study, 245 rodents were trapped, of which the most abundant genera were Apodemus (40%), Mus (24.49%), and Meriones (12.65%). One hundred fifty-three fleas, 37 mites, and 54 ticks were collected on these rodents. The results of all direct and indirect tests were negative for plague. Serological tests were positive for tularemia in 4.8% of trapped rodents.

DISCUSSION

This study is the first report on the presence of tularemia infection in rodents in Western Iran. Since Meriones persicus is a known reservoir for plague and tularemia, and this rodent carried plague and tularemia vectors in Marivan and Sanandaj districts, there is a real potential for the occurrence of these two diseases in this region.

Cluster of ulceroglandular tularemia cases in Slovenia

In Slovenia, a small Central European country, where tularemia cases are very rare and mostly sporadic, six cases of ulceroglandular tularemia were recognised in 2012-2013 in patients residing in or visiting a small geographical area of <6km². Epidemiological data indicated transmission by a tick bite in at least 3/6 patients.

Tularaemia: clinical aspects in Europe

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.

A Preliminary Investigation on Ticks (Acari: Ixodidae) Infesting Birds in Kızılırmak Delta, Turkey

Ticks are mandatory blood-feeding ectoparasites of mammals, birds, reptiles, and even amphibians. Turkey has a rich bird fauna and is located on the main migration route for many birds. However, information on ticks infesting birds is very limited. In the present study, we aimed to determine ticks infesting birds in Kızılırmak Delta, Turkey. In 2014 autumn bird migration season, a total of 7,452 birds belonging to 79 species, 52 genera, 35 families, and 14 orders were examined for tick infestation. In total, 287 (234 larvae, 47 nymphs, 6♀) ticks were collected from 54 passerine birds (prevalence = 0.72%) belonging to 12 species. Ticks were identified as Amblyomma sp., Dermacentor marginatus (Sulzer), Haemaphysalis concinna Koch, Haemaphysalis punctata Canestrini and Fanzago, Hyalomma sp., Ixodes frontalis (Panzer), and Ixodes ricinus (L). The most common tick species were I. frontalis (223 larvae, 23 nymphs, 6♀) followed by I. ricinus (3 larvae, 12 nymphs) and H. concinna (4 larvae, 6 nymphs). Based on our results, it can be said that Erithacus rubecula (L.) is the main host of immature I. frontalis, whereas Turdus merula L. is the most important carrier of immature stages of some ticks in Kızılırmak Delta, Turkey. To the best of our knowledge, most of the tick-host associations found in this study have never been documented in the literature.

Tularemia and plague survey in rodents in an earthquake zone in southeastern Iran

OBJECTIVES

Earthquakes are one the most common natural disasters that lead to increased mortality and morbidity from transmissible diseases, partially because the rodents displaced by an earthquake can lead to an increased rate of disease transmission. The aim of this study was to evaluate the prevalence of plague and tularemia in rodents in the earthquake zones in southeastern Iran.

METHODS

In April 2013, a research team was dispatched to explore the possible presence of diseases in rodents displaced by a recent earthquake magnitude 7.7 around the cities of Khash and Saravan in Sistan and Baluchestan Province. Rodents were trapped near and in the earthquake zone, in a location where an outbreak of tularemia was reported in 2007. Rodent serums were tested for a serological survey using an enzyme-linked immunosorbent assay.

RESULTS

In the 13 areas that were studied, nine rodents were caught over a total of 200 trap-days. Forty-eight fleas and 10 ticks were obtained from the rodents. The ticks were from the Hyalomma genus and the fleas were from the Xenopsylla genus. All the trapped rodents were Tatera indica. Serological results were negative for plague, but the serum agglutination test was positive for tularemia in one of the rodents. Tatera indica has never been previously documented to be involved in the transmission of tularemia.

CONCLUSIONS

No evidence of the plague cycle was found in the rodents of the area, but evidence was found of tularemia infection in rodents, as demonstrated by a positive serological test for tularemia in one rodent.

Francisella species in ticks and animals, Iberian Peninsula

The presence of Francisella species in 2134 ticks, 93 lagomorphs and 280 small mammals from the Iberian Peninsula was studied. Overall, 19 ticks and 6 lagomorphs were positive for Francisella tularensis subsp. holarctica, suggesting, as described for other regions, that lagomorphs may have an important role in the maintenance of F. tularensis in nature. Of the 6 positive lagomorphs, 4 were identified as the European rabbit, Oryctogalus cuniculus. Additionally, 353 ticks and 3 small mammals were PCR positive for Francisella-like endosymbionts (FLEs) and one small mammal was also positive for Francisella hispaniensis-like DNA sequences. Among FLE positive specimens, a variety of sequence types were detected: ticks were associated with 5 lpnA sequence types, with only one type identified per tick, in contrast to 2 lpnA sequence types detected in a single wood mouse (Apodemus sylvaticus). To our knowledge, this is the first report of FLEs in free-living small mammals as well as the first detection of F. hispaniensis-like sequences in a natural setting.

Environmental Monitoring and Surveillance of Rodents and Vectors for Francisella tularensis Following Outbreaks of Human Tularemia in Georgia

Tularemia is a re-emerging bacterial zoonosis, broadly distributed across the northern hemisphere. In Georgia, there is a history of human tularemia outbreaks dating back to the 1940s. In response to outbreaks, health officials initiated long-term field surveillance and environmental monitoring. The objective of our study was to obtain information from 57 years of field surveys to identify species that play a role in the occurrence Francisella tularensis subsp. holarctica in the environment in Georgia. We collected historical data on human outbreaks, field collections, population dynamics of the common vole (Microtus arvalis), and conducted surveys on small mammals and vectors from five regions in Georgia during 1956-2012. Bacterial isolation was conducted using standard culturing techniques, and isolation rates for species were obtained for a subset of years. We used a Spearman rank correlation to test for associations between the density of the common vole and isolation rates. From 1956 through 2012, there were four recorded outbreaks of human tularemia (362 cases). A total of 465 bacterial isolates of F. tularensis subsp. holarctica were obtained from 27 species and environmental samples. The number of isolations was highest in the common vole (M. arvalis; 149 isolates; 32%) and Dermacentor marginatus ticks (132 isolates; 28%); isolation rates ranged between 0-0.91% and 0-0.47%, respectively. Population dynamics of the common vole were not correlated with the isolation rate. Given the history of tularemia re-emergence in Georgia, continued field surveys and environmental monitoring may provide an early indication of outbreak risk in humans. In conclusion, our findings provide evidence of long-standing foci of F. tularensis subsp. holarctica that are likely maintained by the common vole-tick cycle.

Tick-borne infections in human and animal population worldwide

The abundance and activity of ectoparasites and its hosts are affected by various abiotic factors, such as climate and other organisms (predators, pathogens and competitors) presenting thus multiples forms of association (obligate to facultative, permanent to intermittent and superficial to subcutaneous) developed during long co-evolving processes. Ticks are ectoparasites widespread globally and its eco epidemiology are closely related to the environmental conditions. They are obligatory hematophagous ectoparasites and responsible as vectors or reservoirs at the transmission of pathogenic fungi, protozoa, viruses, rickettsia and others bacteria during their feeding process on the hosts. Ticks constitute the second vector group that transmit the major number of pathogens to humans and play a role primary for animals in the process of diseases transmission. Many studies on bioecology of ticks, considering the information related to their population dynamics, to the host and the environment, comes possible the application and efficiency of tick control measures in the prevention programs of vector-borne diseases. In this review were considered some taxonomic, morphological, epidemiological and clinical fundamental aspects related to the tick-borne infections that affect human and animal populations.

10 years of surveillance of human tularaemia in France

Binary file ES_Abstracts_Final_ECDC.txt matches

An overview: tularemia and travel medicine

Tularemia is a bacterial zoonotic infection. The disease is endemic in most parts of the world, has been reported through the northern hemisphere between 30 and 71° N latitude. Francisella tularensis causes infection in a wide range of vertebrates (rodents, lagomorphs) and invertebrates (ticks, mosquitoes and other arthropods). Humans can acquire this infection through several routes including; a bite from an infected tick, deerfly or mosquito, contact with an infected animal or its dead body. It can also be spread to human by drinking contaminated water or breathing contaminated dirt or aerosol. Clinical manifestation of this disease varies depending on the biotype, inoculum and port of entry. Infection is potentially life threatening, but can effectively be treated with antibiotics. Travelers visiting rural and agricultural areas in endemic countries may be at greater risk. Appropriate clothing and use of insect repellants is essential to prevent tick borne illness. Travelers also should be aware of food and waterborne disease; avoid consuming potentially contaminated water and uncooked meat. Physicians should be aware of any clinical presentation of tularemia in the patients returning from endemic areas.

The status of tularemia in Europe in a one-health context: a review

The bacterium Francisella tularensis causes the vector-borne zoonotic disease tularemia, and may infect a wide range of hosts including invertebrates, mammals and birds. Transmission to humans occurs through contact with infected animals or contaminated environments, or through arthropod vectors. Tularemia has a broad geographical distribution, and there is evidence which suggests local emergence or re-emergence of this disease in Europe. This review was developed to provide an update on the geographical distribution of F. tularensis in humans, wildlife, domestic animals and vector species, to identify potential public health hazards, and to characterize the epidemiology of tularemia in Europe. Information was collated on cases in humans, domestic animals and wildlife, and on reports of detection of the bacterium in arthropod vectors, from 38 European countries for the period 1992-2012. Multiple international databases on human and animal health were consulted, as well as published reports in the literature. Tularemia is a disease of complex epidemiology that is challenging to understand and therefore to control. Many aspects of this disease remain poorly understood. Better understanding is needed of the epidemiological role of animal hosts, potential vectors, mechanisms of maintenance in the different ecosystems, and routes of transmission of the disease.

Serosurveillance for Francisella tularensis among wild animals in Japan using a newly developed competitive enzyme-linked immunosorbent assay

Tularemia, a highly infectious zoonotic disease caused by Francisella tularensis, occurs sporadically in Japan. However, little is known about the prevalence of the disease in wild animals. A total of 632 samples obtained from 150 Japanese black bears, 142 Japanese hares, 120 small rodents, 97 rats, 53 raptors, 26 Japanese monkeys, 21 Japanese raccoon dogs, 20 masked palm civets, and three Japanese red foxes between 2002 and 2010 were investigated for the presence of antibodies to F. tularensis by competitive enzyme-linked immunosorbent assay (cELISA) and the commonly used microagglutination (MA) test. Seropositive cELISA and MA results were obtained in 23 and 18 Japanese black bears, three and two Japanese raccoon dogs, and two and one small rodents, respectively. All MA-positive samples (n=21) were also positive by cELISA. Six of seven samples that were only positive by cELISA were confirmed to be antibody-positive by western blot analysis. These findings suggest that cELISA is a highly sensitive and useful test for serosurveillance of tularemia among various species of wild animals. Because this is the first study to detect F. tularensis-seropositive Japanese raccoon dogs, these could join Japanese black bears as sentinel animals for tularemia in the wild in Japan. Further continuous serosurveillance for F. tularensis in various species of wild animals using appropriate methods such as cELISA is important to assess the risks of human exposure and to improve our understanding of the ecology of F. tularensis in the wild.

Detection of Francisella tularensis in voles in Finland

Francisella tularensis is a highly virulent intracellular bacterium causing the zoonotic disease tularemia. It recurrently causes human and animal outbreaks in northern Europe, including Finland. Although F. tularensis infects several mammal species, only rodents and lagomorphs seem to have importance in its ecology. Peak densities of rodent populations may trigger tularemia outbreaks in humans; however, it is still unclear to which extent rodents or other small mammals maintain F. tularensis in nature. The main objective of this study was to obtain information about the occurrence of F. tularensis in small mammals in Finland. We snap-trapped 547 wild small mammals representing 11 species at 14 locations around Finland during 6 years and screened them for the presence of F. tularensis DNA using PCR analysis. High copy number of F. tularensis-specific DNA was detected in tissue samples of five field voles (Microtus agrestis) originating from one location and 2 years. According to DNA sequences of the bacterial 23S ribosomal RNA gene amplified from F. tularensis-infected voles, the infecting agent belongs to the subspecies holarctica. To find out the optimal tissue for tularemia screening in voles, we compared the amounts of F. tularensis DNA in lungs, liver, spleen, and kidney of the infected animals. F. tularensis DNA was detectable in high levels in all four organs except for one animal, whose kidney was F. tularensis DNA-negative. Thus, at least liver, lung, and spleen seem suitable for F. tularensis screening in voles. Thus, liver, lung, and spleen all seem suitable for F. tularensis screening in voles. In conclusion, field voles can be heavily infected with F. tularensis subsp. holarctica and thus potentially serve as the source of infection in humans and other mammals.

One year survey of human rotavirus strains suggests the emergence of genotype G12 in Cameroon

In this study the emergence of rotavirus A genotype G12 in children <5 years of age is reported from Cameroon during 2010/2011. A total of 135 human stool samples were P and G genotyped by reverse transcriptase PCR. Six different rotavirus VP7 genotypes were detected, including G1, G2, G3, G8, G9, and G12 in combinations with P[4], P[6] and P[8] VP4 genotypes. Genotype G12 predominated in combination with P[8] (54.1%) and P[6] (10.4%) genotypes followed by G1P[6] (8.2%), G3P[6] (6.7%), G2P[4] (5.9%), G8P[6] (3.7%), G2P[6] (0.7%), G3P[8] (0.7%), and G9P[8] (0.7%). Genotype P[6] strains in combination with various G-types represented a substantial proportion (N=44, 32.6%) of the genotyped strains. Partially typed strains included G12P[NT] (2.2%); G3P[NT] (0.7%); G(NT)P[6] (1.5%); and G(NT)P[8] (0.7%). Mixed infections were found in five specimens (3.7%) in several combinations including G1+ G12P[6], G2+ G3P[6] + P[8], G3+ G8P[6], G3 + G12P[6] + P[8], and G12P[6] +P[8]. The approximately 10% relative frequency of G12P[6] strains detected in this study suggests that this strain is emerging in Cameroon and should be monitored carefully as rotavirus vaccine is implemented in this country, as it shares neither G- nor P-type specificity with strains in the RotaTeq® and Rotarix® vaccines. These findings are consistent with other recent reports of the global spread and increasing epidemiologic importance of G12 and P[6] strains.

Serological investigation of wild boars (Sus scrofa) and red foxes (Vulpes vulpes) as indicator animals for circulation of Francisella tularensis in Germany

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.

Biofilms: an advancement in our understanding of Francisella species

Our understanding of the virulence and pathogenesis of Francisella spp. has significantly advanced in recent years, including a new understanding that this organism can form biofilms. What is known so far about Francisella spp. biofilms is summarized here and future research questions are suggested. The molecular basis of biofilm production has begun to be studied, especially the role of extracellular carbohydrates and capsule, quorum sensing and two-component signaling systems. Further work has explored the contribution of amoebae, pili, outer-membrane vesicles, chitinases, and small molecules such as c-di-GMP to Francisella spp. biofilm formation. A role for Francisella spp. biofilm in feeding mosquito larvae has been suggested. As no strong role in virulence has been found yet, Francisella spp. biofilm formation is most likely a key mechanism for environmental survival and persistence. The significance and importance of Francisella spp.’s biofilm phenotype as a critical aspect of its microbial physiology is being developed. Areas for further studies include the potential role of Francisella spp. biofilms in the infection of mammalian hosts and virulence regulation.

Francisella tularensis infection in a stone marten (Martes foina) without classic pathological lesions consistent with tularemia

The current report describes the isolation and typing of a strain of Francisella tularensis, the causative agent of tularemia, from the spleen of a stone marten (Martes foina) showing no classic lesions consistent with the disease. The identification of this bacterium, belonging to the World Health Organization risk 3 category and considered to have a low infectious dose, could be performed only because of an ongoing project screening F. tularensis in the environment sensu lato. The findings described herein should alert diagnostic laboratories of the possible presence of F. tularensis in clinical samples in countries where tularemia is endemic even in cases with no consistent anamnesis and from unsuspected animal species.

Tularaemia seroprevalence of captured and wild animals in Germany: the fox (Vulpes vulpes) as a biological indicator

A total of 2475 animals from Germany, both captive and wild, were tested for antibodies againstFrancisella tularensisto obtain more knowledge about the presence of this pathogen in Germany. An indirect and a competitive ELISA served as screening methods, positive and inconclusive samples were confirmed by Western blot. Of the zoo animals sampled between 1992 and 2007 (n = 1122), three (0·3%) were seropositive. The seroconversion of a hippopotamus in Berlin Zoo was documented. From 1353 serum samples of wild foxes (Vulpes vulpes), raccoon dogs (Nyctereutes procyonoides) and wild boars (Sus scrofa), collected between 2005 and 2009 in the federal state of Brandenburg (surrounding Berlin), a total of 101 (7·5%) tested positive for antibodies toF. tularensislipopolysaccharide. Our results indicate a higher seroprevalence ofF.tularensisin wildlife in eastern Germany than commonly assumed. Furthermore, we found foxes and raccoon dogs to be biological indicators for tularaemia.