1. Introduction

Europe has 45 bat species considered indigenous to the continent (http://www.batlife-europe. info/about-batlife-europe/european-bats/, accessed 8 November 2017). This number is being constantly revised as new and cryptic species are identified. All are small- to medium-sized insectivorous bat species although colonies of the Egyptian fruit bat (Rousettus aegyptiacus) are known to colonise islands of the Mediterranean Sea [1]. The role of bats as a source of zoonotic viruses has been recognised over the past three decades with the emergence of viruses such as Hendra virus, Nipah virus and SARS-coronavirus [2]. However, European bats are nocturnal

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

so contact with humans is minimal making them both an elusive species to study and a rare source of zoonotic pathogens [3]. Key amongst these is the European bat lyssaviruses (EBLVs), members of the genus Lyssavirus, family Rhabdoviridae. The type species of the genus is rabies lyssavirus (RABV), the virus responsible for virtually all cases of rabies in the world. The genus contains a growing number of viruses, the majority associated with bat species [4] (Table 1).

discrimination based on genome sequencing [8] and the first complete genome sequence for EBLV-2 was reported in 2007 [9]. Of the other lyssaviruses detected in European bats, WCBV and LLEBV represent single isolations of virus so little is known about the epidemiology of these viruses. The most commonly encountered lyssavirus in European bats is EBLV-1 and almost all detections of this virus are from serotine bats (Eptesicus serotinus) [10]. A more recent addition is Bokeloh bat lyssavirus that is predominantly associated with Natterers bats (Myotis

The Daubenton's Bat (*Myotis daubentonii*, Kuhl, 1817) and Its Role as a Reservoir…

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The first report of EBLV-2 in the UK resulted from the discovery of an adult female bat in the cellar of a public house in Newhaven, Sussex in 1996 [12]. Virus was isolated from brain tissue removed from the bat. Subsequently, reverse transcription polymerase chain reaction (RT-PCR) and sequencing confirmed the virus species by comparison with sequences derived from lyssaviruses known at the time. It was speculated that the bat may have flown across the English Channel but subsequent isolations of virus from other locations in England suggested that the virus was actually endemic long before cases were detected [13]. All detections of EBLV-2 in bats in the UK (isolation of virus or detection of virus in a salivary swab) have been from Daubenton's bats. This pattern has been reflected across Europe with occasional batassociated cases reported in The Netherlands [14], Germany [15], Switzerland [16], Finland [17]

The following sections discuss the biology and ecology of the Daubenton's bat, research on the relationship between EBLV-2 and its reservoir host and a discussion on the transmission of the virus between conspecifics that might explain the persistence of this virus in European bat

The Daubenton's bat was first described by the German naturalist and zoologist, Heinrich Kuhl [1797–1821] in his monograph, Die deutschen Fledermäuse, published in 1817. The name selected for the species was derived from the French naturalist Louis Jean-Marie Daubenton [1716–1800]. Kuhl went on to take part in an expedition to Java to study the islands fauna but developed a fever that subsequently killed him. He was buried in the Botanical Gardens of

Daubenton's bats are considered a medium-sized insectivorous bat with an adult wingspan of up to 27.5 cm and a body length up to 5.5 cm. Adults weigh between 7 and 12 g and have a reddish brown pelt. The common name of the species is the 'water bat' due to its feeding habit. This involves flying low across the surface of water bodies such as lakes, rivers and canals, feeding on a range of water-associated flies. These include chironomid midges, caddisflies and mayflies. Daubenton's bats echolocate in a call range between 35 and 85 kHz, and generally feed within 6 km of their roost. Roost sites range from natural sites such as tree holes to manmade structures, including houses [19]. During the summer, there is a degree of segregation between maternity colonies, dominated by a single male and bachelor roosts [20]. Hibernation

Bogor to the south of Jakarta where his gravestone can still be located.

takes place over the winter months, usually in caves, tunnels and mines.

nattereri) from Germany and France [11].

and Norway [18].

populations.

2. The Daubenton's bat

All can cause encephalitis in mouse models of infection and it is suspected that all are capable of causing rabies in humans. Of these, five have been reported from Europe. European bat lyssavirus type-1 (EBLV-1), EBLV-2, West Caucasian bat lyssavirus (WCBV), Bokeloh bat lyssavirus (BBLV) and Lleida bat lyssavirus (LLEBV). Despite the close association with bats, the first recognised isolation of EBLV-2 was derived from a human case of rabies. The patient was a bat ecologist working in Finland when he developed rabies [5]. Shortly afterward, a related virus was isolated from the brain of a pond bat (Myotis dasycneme). Since then there has been one further case of EBLV-2 infection in a human [6] and continual reports of the virus infection of Daubenton's bats (Myotis daubentonii).

The ability to discriminate between different lyssaviruses was only achieved with the advent of monoclonal antibody panels that show different binding patterns to particular viruses. This first alerted researchers that the viruses present in European bats were distinct from RABV found in North American bats [7]. Antigenic typing has now been superseded by genetic


Table 1. Known lyssaviruses and their association with particular bat species.

discrimination based on genome sequencing [8] and the first complete genome sequence for EBLV-2 was reported in 2007 [9]. Of the other lyssaviruses detected in European bats, WCBV and LLEBV represent single isolations of virus so little is known about the epidemiology of these viruses. The most commonly encountered lyssavirus in European bats is EBLV-1 and almost all detections of this virus are from serotine bats (Eptesicus serotinus) [10]. A more recent addition is Bokeloh bat lyssavirus that is predominantly associated with Natterers bats (Myotis nattereri) from Germany and France [11].

The first report of EBLV-2 in the UK resulted from the discovery of an adult female bat in the cellar of a public house in Newhaven, Sussex in 1996 [12]. Virus was isolated from brain tissue removed from the bat. Subsequently, reverse transcription polymerase chain reaction (RT-PCR) and sequencing confirmed the virus species by comparison with sequences derived from lyssaviruses known at the time. It was speculated that the bat may have flown across the English Channel but subsequent isolations of virus from other locations in England suggested that the virus was actually endemic long before cases were detected [13]. All detections of EBLV-2 in bats in the UK (isolation of virus or detection of virus in a salivary swab) have been from Daubenton's bats. This pattern has been reflected across Europe with occasional batassociated cases reported in The Netherlands [14], Germany [15], Switzerland [16], Finland [17] and Norway [18].

The following sections discuss the biology and ecology of the Daubenton's bat, research on the relationship between EBLV-2 and its reservoir host and a discussion on the transmission of the virus between conspecifics that might explain the persistence of this virus in European bat populations.
