Epidemiological investigation and molecular typing of dermatophytosis caused by Microsporum canis in dogs and cats.

The objective of the present study was investigate the prevalence of dermatophytes in dogs, cats and environment floor through molecular epidemiology tools to identify the genetic profile of these infectious agents. This was an observational study with cross-sectional surveys design. Sample were collected from the hair and skin of 52 dogs and cats with the clinical suspicion of dermatophytosis, over a period of one year in Maringá, in the state of Paraná, Brazil. Household samples (carpets and floor), were collected from animals that were positive for dermatophytosis by morphological colonies characteristics, and samples of dogs or cats living in the same household as with the positive animals were also collected. After mycological confirmation, molecular typing was performed by random amplified polymorphic DNA (RAPD). Microsporum canis was the unic dermatophyto isolated whose prevalence was 26.9% (14/52) in animals with the clinical suspicion of dermatophytosis and four other animals that lived with positive animals. As some animals had more than one lesion site, there were 22 total positive cultures from samples from animals and another ten from abiotic sources. The majority of the animals that provided positive cultures for M. canis were aged up to five months (77.8%) and were female (66.7%). Molecular typing using the P1 primer revealed genetically distinct profiles in the symptomatic, asymptomatic and environmental animal samples, or the same animal, furthermore, showed that M. canis could have microevolution.

Decontamination of 70 foster family homes exposed to Microsporum canis infected cats: a retrospective study.

BACKGROUND: Dermatophytosis is a superficial fungal skin disease of animals. A key part of treatment is cleaning and disinfection of the environment to prevent false-positive results due to fomite carriage. Furthermore, there is a perception in the lay literature that decontamination of homes is difficult or impossible. CLINICAL SUMMARY: Data from a 10 year period identified 70 foster family homes where Microsporum canis infected cats had lived for varying periods of time. Mechanical debris was removed from the rooms housing the cats, the areas cleaned with over-the-counter household detergents, rinsed and hard surfaces disinfected with 1:100 concentration household bleach or accelerated hydrogen peroxide. Thirty-eight homes were completely decontaminated after one cleaning post removal or cure of the cat. Of the remaining homes, decontaminated was achieved after one (n=28), two (n=2) or three (n=1) additional cleanings. Complete decontamination was not possible in one home; the foster family was admittedly noncompliant. There was no evidence of disease transmission to other animals or people. CONCLUSIONS: Environmental decontamination is not difficult in homes exposed to M. canis and can be accomplished with established procedures.

A 10-Year Study of Dermatophytoses in Isfahan, Iran.

Dermatophyte infections are very common worldwide and their epidemiological characteristics vary according to the geographical region and have altered in the last decades. The aim of the present investigation was to determine the diversity of causative agents of dermatophytoses and describe the epidemiological condition of infection in Isfahan, Iran, between 2003 and 2012. Specimens were collected from hair, nail, and skin and were examined by conventional methods such as direct microscopy, culture on sabouraud dextrose agar with chloramphenicol and cycloheximide (Mycosel agar) and sabouraud glucose agar, Trichophyton agars, growth on rice grains, urease test, and hair perforation test. Of 13,469 clinically suspected cases, 11.5% were affected with dermatophytoses. Tinea capitis was the most frequent form of infection (52.7%), followed by tinea corporis (24%), tinea pedis (8.9%). Trichophyton verrucosum was the most prevalent causative agent (40.6%), followed by T. mentagrophytes var. interdigitale (17.6%), Epidermophyton floccosum (13%), T. violaceum (12%), T. rubrum (4.1%). Age range of patients was between 1 and 80 years. Housewives were the most patients in our study. The study emphasizes importance of epidemiological surveys of dermatophyte species for the better management of infection.

Pathogenesis of tinea.

Dermatophytes are hyphomycetes that can degrade keratin. This puts them in a position to cause infections of the keratin-containing superficial skin. The resulting clinical picture is called tinea. The pathogenesis and course of tinea is decisively determined by pathogen-related factors and by the defense mechanisms of the host. An infection starts with an adherence of fungal propagules, followed by the formation of hyphae that can spread within the tissue. This process is accompanied by a release of fungal enzymes and other pathogenic factors. Next keratinocytes are activated, the epidermal barrier is destroyed, epidermal proliferation is enhanced and defensins are expressed within the epidermis. In addition, innate and specific immune responses are initiated, involving neutrophilic granulocytes, macrophages, antibodies and T cells. The cellular mechanisms are thought to be crucial for healing. Special conditions apply to nail infections, because within nail plates the fungi are not accessible to effective defense mechanisms, as well as to infections of hair follicles that contain specific concentrations of steroid hormones. Dermatophytes that penetrate into the dermis can cause granulomatous inflammatory reactions and systemic immune reactions are supposed to be a trigger of so-called id reactions.

[Description of a severe and rare case of tinea barbae in the mental region]. / Descrizione di un grave e raro caso di tinea barbae della regione mentoniera.

The authors report a case of tinea barbae which initially presented clinical and microscopic symptoms that led to the suspected diagnosis of a rapidly developing malignant tumour. A more detailed diagnosis and multi-specialist collaboration enabled the pathology to be correctly diagnosed and treated.

Microsporum gypseum infection in Aids patient: a case report

Relato de caso de tinea corporis por Microsporum gypseum em paciente com Aids de 36 anos. Segundo a literatura, este dermatófito näo é um agente comum neste grupo de pacientes. As lesöes eram psoriasiformes, generalizadas e näo responderam ao tratamento com cetoconazol e itraconazol

Variación en cepas de microsporum canis bodin, aisladas de infecciones humanas en áreas geográficas limitadas / Variation in microsporum canis bodin strains isolated from human infections in limited geographic areas

En una área geografica que incluye la ciudad de Santiago y Valparaíso, analizamos 31 cepas de Microsporum canis aisladas desde niños prepuberes con dermatofitosis (24 desde cuero cabelludo y 7 de piel), con la finalidad de analizar su variación fenética en 5 medios de cultivo sólidos (Sabouraud, Lactritmel, Papa dextrosa, Czapek y Nitrito sucrosa agar). Se seleccionaron 19 características macro y microscópicas, 9 de ellas consideradas de valor taxonómico primario, las que se estudiaron en todos los medios a los 14 días de incubación a 27ºC, a partir de subcultivos provenientes de su primer aislamiento clínico. Los datos obtenidos de los 3 primeros medios de cultivos básicos, se analizaron estadísticamente. Solo se observaron coincidencias en estos tres medios, al considerar cada parámetro por separado, principalmente: presencia de microconidios (8/31), forma del macroconidio (10/31) y color del reverso (23/31). El medio que más discrimina es el Sabouraud, al producir las mayores diferencias entre cepas; en segundo lugar Papa dextrosa y, finalmente Lactritmel, que por su menor discriminación permite obtener más agrupaciones. En agar nitrito de sodio, se apareció la conidiogénesis más estable. Se determinó la presencia de 2 cepas de Microsporum canis sub. sp. pulverulentum, situación no registrada anteriormente en nuestro medio ambiente

[Laboratory diagnosis of dermatophytosis: 10 years experience in the western area of Santiago]. / Diagnóstico de laboratorio de las dermatofitosis: experiencia de 10 años en el area occidente de Santiago.

From 1979 to 1988, 3890 positive samples for dermatophytes obtained at the Dermatology Service of Hospital San Juan de Dios (Western Santiago area) were analyzed for type of fungus involved and for relative yield of direct examination compared to culture. Direct examination was performed on samples treated with 20% KOH and stained with rhodamine. Cultures were obtained on Agar Sabouraud medium with addition of gentamycin and chloramphenicol. Yield of direct examination was 97.2% compared to 85% for culture. According to anatomic location, M canis was isolated from nearly all cases of T capitis. In cases of T pedis, nail mycosis, crural and palmar infections the most frequent species were T rubrum and T mentagrophytes M canis and T rubrum were responsible for infections of the body.