Eur J Wildl Res (2007) 53:238–240 DOI 10.1007/s10344-007-0088-0
SHORT COMMUNICATION
Dermatophytosis caused by Microsporum canis in Eastern cottontail (Sylvilagus floridanus) P. Tizzani & M. G. Gallo & A. Peano & A. Molinar Min & C. Martínez-Carrasco Pleite & P. G. Meneguz
Received: 17 August 2006 / Revised: 9 January 2007 / Accepted: 14 January 2007 / Published online: 22 February 2007 # Springer-Verlag 2007
Abstract Eastern cottontail (Sylvilagus floridanus, fam. Leporidae) has previously been shown to be a potential healthy carrier of dermatophyte fungi both geophilic (Microsporum gypseum, M. cookei, Trichophyton ajelloi, T. terrestre) and zoophilic (M. canis, T. mentagrophytes). In this communication, the first case, to the best of our knowledge, of a symptomatic dermatophyte infection in S. floridanus is described. Keywords Fungi . Zoonosis . Arthroconidia
Introduction Dermatophytes (genus Microsporum, Tricophyton, Epidermophyton) are fungi with great affinity for keratin, the mayor constituent of hairs, nails and corneum layer of the epidermis. On the basis of their natural habitat, they can be divided into three groups (Ajello 1968): geophilic, anthropophilic and zoophilic.
P. Tizzani : M. G. Gallo : A. Peano (*) : A. Molinar Min : P. G. Meneguz Dipartimento di Produzioni Animali, Epidemiologia ed Ecologia, Università di Torino, Via Leonardo da Vinci 44, 10095 Grugliasco (TO), Italy e-mail:
[email protected] C. Martínez-Carrasco Pleite Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Murcia, Campus Universitario de Espinardo, 30100 Murcia, Spain
Microsporum canis is the most common zoophilic dermatophyte affecting pets and can be transmitted from animals to man (Foil 1998). Eastern cottontail (Sylvilagus floridanus) is a synanthropic species that can be easily observed near urban centres where it can reach high population density. This lagomorph was introduced as a game from North America in France (1953), Italy (1966), Spain (1980) and Switzerland (1982), but it has become naturalised only in Piedmont, northwest Italy. In this region, over the last 20 years, it has been actively expanding both in territory and in numbers from west to east in the Po Valley (Spagnesi et al. 1999; Silvano et al. 2000; Tizzani 2000).
Case description In December 2002, an adult Eastern cottontail found dead in Volvera (Province of Turin-Piedmont) was submitted to the Parasitology laboratory of the Veterinary Faculty of Turin to be examined because of the presence of dermatological lesions. It was male and in poor trophic condition with few fat deposits and a weight of 952 g. The necropsy showed multiple alopecic areas on the head and the neck, with some broken and frayed hairs and little evidence of inflammation. Lesions were not exudative, and moderate scaling and dandruff were present. On ears, nose and around the eyes, the alopecic patches were confluent and presented irregular margins, whereas on the neck they were annular and 1–2 cm in diameter. No other significant external or internal lesions were reported. Mite research by skin scraping and bacteriological culture on blood agar by a sterile swab gave negative results. The microscopic hair examination revealed the presence of arthroconidia surrounding the hair shafts
Eur J Wildl Res (2007) 53:238–240
Fig. 1 Microscopic appearance of a hair collected from skin lesion periphery and cleared with NaOH (40×). The hair shaft is swollen and is invaded by tiny spherical unstained spores (arthroconidia; black arrows)
(Fig. 1). Culture from hair on Sabouraud’s dextrose agar supplemented with chloramphenicol 0.05 g/l and cycloheximide 0.5 g/l (Mycobios Selective Medium, Oxoid) yielded, after 5 days at 25°C, radiating, thin, white fungal colonies with yellow reverse. Microscopical examination showed undifferentiated hyphae and rough-walled macroconidia. These latter were spindle-shaped with slightly bent, verrucose, rostrate apex and presented 6–12 cells with tick cell walls and thinner septa. Some pyriform microconidia were also present. According to Rebell and Taplin (1974) identification keys, this strain was identified as M. canis.
Discussion To the best of our knowledge, this clinical case represents the first report of a symptomatic infection by M. canis in Eastern cottontail, which has recently been shown to be a healthy carrier of this fungus in Piedmont the whole year round (Gallo et al. 2005b). Clinical evidence of dermatophytosis generally occurs in consequence of stress factors of various origins (Foil 1998). Transition of infection to a clinical form may have been favoured by poor trophic conditions of the animal, whose weight was below the mean weight of Eastern cottontail in Piedmont (1,109 g) as previously described (Tizzani 2000). During necropsy, a specific cause for emaciation was not found. Even if it may be attributed to poor feeding and malnutrition due to bad environmental conditions of winter months and animals overdensity, data about seasonal population trends of S. floridanus in Piedmont are not complete enough to confirm this hypothesis (Tizzani 2000). M. canis is usually correlated with a domestic environment and associated with dog and cat, that represents its
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most important carrier. Isolation of this fungus from the haircoat indicates either true infection, sometimes subclinical, or fomite carriage deriving from exposure to a contaminated environment (Foil 1998). M. canis has been worldwide reported also in fur animals as well as in some synanthropic species (Rattus rattus, R. norvegicus and Mus musculus; Mantovani and Morganti 1977). It has been reported in asymptomatic marmots (Marmota marmota; Gallo et al. 2005a) and wild foxes in northern Italy (Gallo et al. 1990; Mancianti et al. 1993). It has not been found in other European surveys on hair-coat microflora of some freeranging mammals (Otčenášek and Dvořák 1962; Otčenášek et al. 1980; Poglayen et al. 1981; Banaszkiewicz 1985; Chabasse et al. 1987; Mancianti et al. 1997). Stray or domestic dogs and cats may represent the source of infection for the clinical case described. Fox, recently shown to be a potential carrier of M. canis (Gallo et al. 1990; Mancianti et al. 1993), may also play an important role through its predatory behaviour towards the Eastern cottontail. Domestic-farmed rabbits are considered preferential hosts of another zoophilic dermatophyte, Trichophyton mentagrophytes, which is widespread especially in intensive farms (Van Cutsem et al. 1985). Otherwise, many episodes of infection caused by M. canis have been signalled (Van Cutsem et al. 1985; Torres-Rodrigues et al. 1992; Canny and Gamble 2003). Therefore, domestic rabbits may be the source of infection caused by these two species of dermatophytes for Eastern cottontail. In conclusion, this case confirms the role of S. floridanus as a host of M. canis. Given the zoonotic potential of this fungus and the presence of cottontails in house and public gardens of urban peripheries, a sanitary risk may be assumed for human in consequence of a direct contact with these animals or of environmental contamination with fungal arthroconidia (Gallo et al. 2005b).
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