Ringworm by Trichophyton erinacei in calves: description of two Italian outbreaks
Trichophyton (T.) erinacei is a zoonotic dermatophyte mainly isolated from hedgehogs. In other hosts (human or animals) it can cause skin infections, determining typical clinical features of dermatophytosis. It has never been reported in cattle, where instead T. verrucosum is frequently isolated, particularly in calves. The present case report describes two outbreaks (case A and case B) of cattle ringworm caused by T. erinacei occurred in Northern Italy; the first case involved a group of 5 months old Bruna Alpina calves, while the second one concerned a group of about 24 months old Italian Frisona cows. The herd A was normally subjected to a regular vaccination protocol against T. verrucosum, but the calves involved in the outbreak had not yet been vaccinated. Crusts, alopecic and pruritic skin lesions, appeared about 4 months before and mainly distributed on the head, trunk and flanks, were noticed in all the animals involved. The veterinarian of one of the two farms showed an abdomen skin lesions compatible with dermatophytosis about 2 weeks after the appearance of the disease in animals. Animal and human hairs/crusts samples were collected for mycological investigations by cultural and molecular methods (PCR and sequencing). Colonies observed showed macro- and microscopical features of a dermatophyte attributable to T. mentagrophytes. The strain has instead been confirmed as T. erinacei by molecular analysis. The described cases showed that T. erinacei can cause bovine ringworm, with clinical features completely comparable to those determined by T. verrucosum. The use of vaccination in some animals of the herd A contributed to their protection against the mycosis, as demonstrated by the fact that only non-vaccinated animals showed T. erinacei skin lesions. The use of different laboratory diagnostic methods was essential to reach a correct fungal identification. Furthermore, it is possible to affirm that this is the first Italian isolation of T. erinacei from calves.