The Value of Enzyme-linked Immunosorbent Assay (ELISA) in the Sero-diagnosis of Canine Dermatophytosis Due to Microsporum Canis

Abstract— Fourteen sera from dogs naturally or experimentally infected with Microsporum canis were examined by enzyme-linked immunosorbent assay (ELISA) in order to study the humoral response to infection. A group of 12 animals (7 laboratory dogs and 5 dogs from the natural environment) was used as controls. ELISA optical density (OD) values in twofold serial dilutions from 1:100 to 1:51200 were compared between the groups. Significant antibody response to infection with M. canis was observed in naturally and experimentally infected animals and confirmed by threshold determination. Specificity for the dermatophyte fungi was tested by performing cross-reactivity assays with three fungal antigens, Malassezia pachydermatis, Candida albicans and Aspergillus fumigatus. There were no statistically significant indications of cross-reactions, except with anti-A. fumigatus IgG, where differences were noticed within the groups of naturally infected animals and controls. The use of ELISA technique in sero-diagnosis of dermatophytosis in dogs is discussed. Résumé— 14 sérums chiens infectés naturellement ou expérimentalement par Microsporum canis ont été testés par une technique Immunoenzymatique (ELISA) pour étudier la réponse immunitaire humorale à cette infection. Le groupe témoin était composé de 12 animaux (7 chiens de laboratoire et 5 chiens d'un milieu naturel). Les valeurs de densité optique (DO) obtenues avec des dilutions sériées de raison 2 des sérums (1:100 à 1:51,500) ont été comparées entre chaque groupe. Des taux significativement élevés d'anticorps spécifiques de Microsporum canis ont été retrouvés chez les animaux infectés naturellement et expérimentalement et confirmés par l'établissement d'un seull de positivité. La spécificité de la technique vis-à-vis des dermatophytes a été appréciée en effectuant des tests d'antigénicité croisée avec des Malassezia pachydermatis, Candida albicans et Aspergillus fumigatus. II n'y avait pas de réactions croisées significatives, exception faite des IgG spécifiques d'A. fumigatus, pour lequel il existait des differences de réponse entre les animaux infectés naturellement et le groups témoin. L'utilisation d'une technique ELISA dans le diagnostic des dermatophyties canines est discutées. Zusammenfassung— Vierzehn Seren von Hunden, die natürlich oder experimentell mit Microsporum canis infiziert waren, wurde mit dem ELISA-Verfahren (Enzyme Linked Immunosorbent Assay) untersucht, um die humorale Antwort auf die lnfektion zu verfolgen. Eine Gruppe von 12 Tieren (7 Laborhunde und 5 Hunde aus normaler Haltung) dienten als Kontrolle. ELISA-optische Dichtewerte (OD) in zweifacher serieller Verdünnung von 1:100 bis 1:51200 wurden zwischen beiden Gruppen verglichen. Bei den natürlich und experimentell infizierten Tieren konnte eine signifikante Antikörperreaktion auf die lnfektion mit M. canis beobachtet und durch Schwellenwertbestimmung bestätigt werden. Die Spezifität für Dermatophyten wurde überprüft, indem Kreuzreaktionsproben mit drei Pilzantigenen, Malassezia pachydermatis, Canidida albicans und Aspergillus fumigatus, durchgeführt wurden. Statistisch signifikante Anzeichen für Kreuzreaktionen konnten nicht nachgewiesen werden, außer bei Anti-A. fumigatus-IgG, bei dem Unterschiede innerhalb der Gruppe der natürlich infizierten und der Kontrolltiere beobachtet wurden. Es wird über die Brauchbarkeit der ELISA-Technik für die Serodiagnose von Dermatophyten bei Hunden diskutiert. Resumen Se examinaron un total de 14 sueros procedentes de perros infectados de forma natural y artificial con Microsporum canis por el método de enzima ligado de inmunoabsorbencia, (ELISA), con el fin de estudiar la respuesta humoral a la infección. Como controles, se usaron un grupo de 12 animales (7 perros de laboratorio y 5 perros que vivían en condiciones naturales). Los valores de densidad óptica ELISA, (OD), fueron comparados entre los grupos en dos diluciones seriadas de 1:100 a 1:51,200. Una respuesta significativa de anticuerpos a la infección con Microsporum canis fue observada en perros infectados de forma natural y artificial, y confirmada por la determinación del punto crítico. La especificidad del dermatofito füngico se estudió por medio de ensayos de reactividad cruzada con otros tres antigenos fúngicos, Malassezia pachydermatis, Candida albicans y Aspergillus fumigatus. No se encontraron indicaciones de reacciones cruzadas estadísticamente significativas, excepto con la IgG de A. fumigatus, donde se advirtieron diferencias en el group de animales infectados naturalmente y en el grupo control. El uso de la téchnica ELISA en el diagnóstico serólogico de las dermatofilosis en el perro, es discutido.     

Synergistic inhibition of the growth in vitro of Microsporum canis by miconazole and chlorhexidine

An agar dilution technique was used to assess the minimum inhibitory concentrations (MIC) of miconazole, chlorhexidine and a 1:1 combination of both agents for 10 isolates of Microsporum canis. For nine of 10 of the isolates, a combination of miconazole and chlorhexidine was more effective than either agent alone; fractional inhibitory concentration indices indicated a synergistic effect for five isolates and an additive effect for four. These results illustrate the potent antimycotic effect of miconazole and chlorhexidine against M. canis and are in accordance with previous clinical studies that showed the value of using miconazole and chlorhexidine shampoo in association with oral griseofulvin in the treatment of feline dermatophytosis caused by M. canis.     

奶牛皮肤真菌的分离及鉴定

2007年春季,合肥市某奶牛场爆发皮肤真菌病。为了弄清本病的病原及常见腐生真菌的数量和种类．通过取奶牛患部病料10份和临床健康奶牛的样本40份,进行直接镜检、分离培养与鉴定和致病性试验,结果确诊为由犬小孢子菌引起的皮癣病,同时分离出腐生真菌6个属。本研究为奶牛皮肤菌病的临床诊断和治疗提供依据,并具有重要的公共卫生意义。     

The First Case of Feline Infectious Peritonitis-like Pyogranuloma in a Ferret Infected by Coronavirus in Japan

A male ferret, which was purchased from abroad at 9 months of age, had shown significant weight loss starting at 13 months of age. The ferret subsequently showed decreasing motor activity and recumbency and was euthanized at 14 months of age. At necropsy, a white, quail egg-sized mass was found in the mesentery. Histopathologically, multifocal granulomas consisting of necrotic foci, macrophages, fibroblasts and plentiful fibrous connective tissues were observed in the mesenteric mass. Surrounding the granulomas, inflammatory cell infiltration consisting of neutrophils, lymphocytes and plasmacytes was observed diffusely and significantly. Immunohistochemistry revealed small numbers of macrophages around necrotic foci that were positively stained for anti-mouse feline coronavirus. Electron microscopically, the cytoplasm of the macrophages contained viral particles, which were identified as coronavirus. The histopathological features in this ferret were similar to those in cats with feline infectious peritonitis (FIP). This was the first case in ferrets in Japan.     

Evaluation of the dermatophyte test medium RapidVet-D

The performance of the dermatophyte test medium (DTM) RapidVet-D was assessed using hair samples collected from experimentally infected guinea pigs. Three dermatophyte species were included in the study: Microsporum canis , Trichophyton mentagrophytes and Trichophyton equinum . DTM substrates were inoculated with infected hairs and scales, incubated at 18, 21, 24, 27 or 37 °C and examined daily for 15 days. The rapidity of colour change was clearly related to the incubation temperature and to the number of infected hairs deposited on the reactive substrates. With the optimum incubation temperature 27 °C, a systematic colour change could be observed only a few days post-inoculation: 3 days with M. canis infected hairs, 4 days with T. equinum and 5 days with T. mentagrophytes .     

IMAGING DIAGNOSIS—SUBLUMBAR PSEUDOMYCETOMA IN A PERSIAN CAT

A 6-year-old Persian cat was examined for constipation, anorexia, and vomiting that was subsequently found to be due to a pseudomycetoma originating from the descending colon and sublumbar region, and causing mechanical obstruction of the colon and rectum. Multiple discrete hyperechoic foci likely representing fungal grains within the lesion gave the mass a coarse echotexture on ultrasound and was supportive of the diagnosis and computed tomography allowed delineation the extent of the mass. A pseudomycetoma is a granulomatous/pyogranulomatous reaction that surrounds dermatophytic fungal hyphae. Definitive diagnosis of a dermatophytic pseudomycetoma requires identification of the etiologic agent by cultivation or immunohistochemical staining. A pseudomycetoma should be included in the differential diagnosis for an abdominal mass in a Persian cat, especially is accompanied by the sonographic findings noted above.     

Isolation of Dermatophytes from the Haircoats of Stray Cats from Selected Animal Shelters in two Different Geographic Regions in the United States

Résumé— Le but de cette étude était de déterminer la prévalence des isolements de Microsporum canisà partir de chats apparemment sains dans des refuges de deux régions de climats différents aux Etats-Unis. Deux cents chats (chats sans signes apparent de maladie) provenant d'une région froide et séche et d'une région chaude et humide ont étéétudiés et la technique de la brosse à dents utilisée pour la mise en culture et la rechehe de Dermatophytes. Cinq espèces de Dermatophytes communément associées aux dermatophyties humaines et animales ont été isolées: M. canis (n= 8), Trichophyton verrucosum (n= 5), T. mentagrophytes (n - 1), T. rubrum (n= 16), et Epidermophyton spp. (n= 5). Microsporum canis n'a été isolé que chez les chats vivant dans le Sud et principalement sur des chatons. Trichophyton rubrum a surtout été isolé chez les chats du nord. La prévalence de M. canis chez les chats sains était dans cet étude de 4 pourcent et la prévalence totale de tous les pathogénes de 17,5 pour cent. [Isolation of dermatophytes from the haircoats of stray cats from selected animal shelters in two different geographic regions of the United States. (Isolement de dermatophytes du pelage de chats errants pris dans des refuges de deux regions différentes des Etats-Unis.) Zusammenfassung— Ziel der Studie war, die Prävalenz von Microsporum canis-Isolaten von scheinbar gesunden Katzen in Tierheimen in zwei klimatisch unterschiedlichen Regionen der Vereinigten Staaten festzustellen. Zwei hundert Katzen (Katzen ohne makroskopische oder offenscichtliche physische Anzeichen von Krankheit) aus Tierheimen in einer relativ kalt-trockenen geographischen Region und einer feucht-war-men Region der Vereinigten Staaten wurden untersucht und aus dem Haarkleid mittels Zahnbürstentechnik Pilzkulturen angelegt. Es wurden fünf Arten von Dermatophyten identifiziert, die häufig mit menschlichen oder tierischen Hautpilzerkrankungen verbunden sind: M. cams (n= 8), Trichophyton verruscosum (n= 5), T. mentagrophytes (n= 1), T. rubrum (n= 16) und Epidermophyton spp. (n= 5). Microsporum canis wurde nur von Katzen aus dem Süden isoliert, vorwiegend von Katzenwelpen. Trichophyton rubrum wurde häufiger von Katzen aus dem Norden isoliert. Die Prävalenz von M. canis bei scheinbar gesunden Katzen in dieser Studie betrug 4 Prozent, die Gesamtprävalenz aller pathogenen Keime betrug 17,5 Prozent. [Isolation of dermatophytes from the haircoats of stray cats from selected animals shelters in two different geographic regions in the United States (Isolierung von Dermatophyten aus dem Fell von streunenden Katzen aus ausgewahlten Tierheimen in awei verschiedenen geographischen Regionen der Vereinigten Staaten.) Abstract— The purpose of this study was to determine the prevalence of Microsporum canis isolation from apparently healthy cats in shelters in two different climatic regions of the United States. Two hundred cats (cats without gross or obvious physical illness) from animal shelters in a relatively cold dry geographic region and a warm humid region of the United States were examined and their haircoat cultured for fungi using the toothbrush technique. Five species of dermatophytes commonly associated with either animal or human dermatophytosis were identified: M. canis (n= 8), Trichophyton verruscosum (n= 5), T. mentagrophytes (n= 1), T. rubrum (n= 16), and Epidermophyton spp. (n = 5). M. canis was isolated only from cats in the south, predominantly from kittens. T. rubrum was isolated more commonly from cats from the north. The prevalence of M. canis in apparently healthy cats in this study was 4 per cent and the overall prevalence of all pathogens was 17.5 per cent.