White-Nose Syndrome Confirmed in Italy: A Preliminary Assessment of Its Occurrence in Bat Species.

Laura Garzoli,Carolina Girometta,Angela Boggero,Katia Varello,Paolo Debernardi,Elena Patriarca,Anna Maria Picco,Andrea Cappelleri,Elena Bozzetta,Marco Riccucci

doi:10.3390/jof7030192

Abstract

Although no mass mortality has been recorded so far, the precise demographic effect of white-nose syndrome (WNS) on European bats still remains to be ascertained. Following the first isolation of P. destructans in Italy, further surveys were performed to assess the distribution of the fungus in NW Italy and its effects on bats. Data were collected from March 2019 to April 2020 at sites used for hibernation (six sites) and/or for reproduction (four sites) in Piedmont and Aosta Valley. A total of 138 bats, belonging to 10 species, were examined to identify clinical features possibly related to the fungal presence. Culture from swabs and the molecular identification of isolates confirmed the presence of P. destructans in bats from five sites, including two maternal roosts. Dermal fungal infiltration, the criterion to assess the presence of WNS, was observed in biopsies of bats belonging to Myotis blythii, M. daubentonii, M. emarginatus and M. myotis. This is the first report of the disease in Italy. The results suggest a greater susceptibility to the infection of the genus Myotis and particularly of M. emarginatus, possibly due to the long length of its hibernation period. Other fungal dermatophytes were also observed.

Highlights

An emerging fungal disease of bats—white-nose disease (WND) or white-nose syndrome (WNS)—has devastating effects on North American bat populations
Daubentonii, M. emarginatus, and M. myotis, already reported in the literature to be affected by the disease in Europe [39]
Puechmaille and co-authors [20] suggested a low prevalence of the disease in the Mediterranean region due to the short hibernation period and the high temperatures recorded in hibernacula, and Martinkova and co-authors [40] presented models predicting that the occurrence and invasiveness of P. destructans infection in Italy are marginal

Summary

Introduction

An emerging fungal disease of bats—white-nose disease (WND) or white-nose syndrome (WNS)—has devastating effects on North American bat populations. The disease may represent the largest mammalian wildlife mortality event in recorded history [2] It is caused by the psychrophilic fungus Pseudogymnoascus destructans (formerly Geomyces destructans), a pathogen firstly discovered in Upstate New York in 2006 [3,4]. The fungus infects hibernating bats while their immunological response is limited by the torpor [5]. It initially grows on the skin’s surface and progresses by invading the underlying tissues, where hyphae can form cup-like epidermal erosions and invade hair follicles, sebaceous glands, and the nearby connective tissue [5,6]. The diagnosis of the disease requires both the demonstration of the presence of the fungus in the skin—via PCR or through culture—and histopathology to identify the presence of the typical dermal lesions [16]

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