Isolation of Trichophyton mentogrophytes var mentogrophytes from naturally infected laboratory albino rats: experimental infection and treatment in rabbits

I K Zangana,Nawzat Issa

doi:10.33899/ijvs.2009.5727

Abstract

The present study demonstrated for the first time the occurrence of dermatophytosis in naturally infected rats and fromasymptomatic and from breeding boxes of white rats kept in animal housing of college of Veterinary Medicine, University ofDohuk, Iraq. The prevalence rate of infection was (28%), clinically infected rats characterized by appearance of scaly ovoidtype lesions with crusty edge and patch of hair loss mostly seen on the back, neck and face of the infected rats, itching wasreported in some rats. Only one species of the trichophyton, T. mentogrophytes var mentogrophytes was isolated with growthrate (85.71%) of samples collected from clinically infected rats, and (28.57%) from asymptomatic and from breeding cages,the growth was observed within the 21 days at 25ºC on Sabouraud's Dextrose Agar. Lacto phenol cotton blue staining slides ofT. mentogrophytes var mentogrophytes revealed both microconidia and macroconidia. Microconidia found in numerousnumbers often in dense cluster which were hyaline, smooth walled and predominantly spherical to sub spherical in shape,varying numbers of chlamydoconidia. Spiral hyphae and smooth, thin walled clavate shaped multicelled macroconidia werealso present. The study also dealt with experimental infection in rabbits with T. mentogrophytes var mentogrophytes andtreated by two drugs, natural herbal preparation of acidic pomegranate (Punica granatum) fruit and synthetic nystatineointment. The complete recovery of lesions was recorded after 14 days and 21 days of topical application of a pomegranateand nystatine ointment for 5 successive days respectively.

Highlights

Dermatophytosis is a fungal infection of the skin caused by dermatophytes-filamentous fungi (Keratiniphylic fungi) which have ability to invade the epidermis and keratinized structure derived from it such as hair or nails [1]
Animal sampling The study was conducted on 75 small white rats kept in laboratory breeding boxes in the college of Veterinary Medicine, University of Dohuk
Clinical Signs Examination of the naturally infected rats in breeding boxes showed that 21/75(28%) had typical signs of disease. These were scaly ovoid type lesions with crusty edge with patch hair loss, these lesions most often seen on the back, neck and face of the infected rats, but can appeared on the other area of the body and some cases were suffered from itching Fig [1]

Summary

Introduction

Dermatophytosis is a fungal infection of the skin caused by dermatophytes-filamentous fungi (Keratiniphylic fungi) which have ability to invade the epidermis and keratinized structure derived from it such as hair or nails [1]. They have a very wide range hosts, including rodents, rabbits, carnivores and people [2]. The main causes of ringworm in white rats are: Trichophyton mentogrophytes [5]. Other isolated that has been seen are T.ajello, T.schoenleini ,T.terrester, Microsporum gallinae,M.gypseum and M. cookie [5,6]. Isolating and identifying of the common cause of dermatophytosis in laboratory white rats

Methods

Results

Conclusion