A review of the biology of canine skin with respect to the commensals Staphylococcus intermedins, Demodex canis and Malassezia pachydermatis

Abstract

Skin disease associated with the cutaneous commensal organisms Staphylococcus intermedius, Malassezia pachydermatis and Demodex canis is frequently encountered in veterinary medicine. In treatment the aim is elimination of the commensal, but recurrence of skin disease is not unusual. In this review, these potentially pathogenic commensals and their ecology are discussed with particular reference to skin biology and the surface ecosystem. The strategies employed by the micro‐organisms for survival and the defence mechanisms of the host are considered. Disease occurs when the virulence of the commensal overwhelms the resistance of the host. It is hoped that an understanding of the complex nature of the skin and its commensals will lead to a better understanding of those diseases associated with commensals and in consequence more effective treatment. Résumé— Les dermatoses associées aux organismes commensaux cutanés Staphylococcus intermedius, Malassezia pachydermatis et Demodex canis sont fréquentes en médecine vétérinaire. Le traitement vise àéliminer le commensal, mais les récidives sont fréquentes. Dans cet article, les commensaux potentiellement pathogènes et leur écologie sont discutés avec une référence particulière à la biologie cutanée et à l'écosystème de surface. Les stratégies employées par les microorganismes pour survivre et les mécanismes de défense de l'hote sont présentés. La pathologie se développe lorsque la virulence du commensal outrepasse la résistance de l'hote. Il faut espérer que la compréhension de la nature complexe de la peau et de ses commensaux, permettent une meilleure compréhension des pathologies associées à ces commensaux et par conséquent un traitement plus efficace. [Mason, I. S., Mason, K. V., Lloyd, D. H. A review of the biology of canine skin with respect to the commensals Staphylococcus intermedius, Demodex canis and Malassezia pachydermatis (Une revue de la biologie de la peau concernant les commensaux Staphylococcus intermedius, Demodex canis et Malassezia pachydermatis). Veterinary Dermatology 1996; 7: 119–132.] Resumen En medicina veterinaria son frecuentes las dermatopatías asociadas a los microorganismos comensales Staphylococcus intermedius, Demodex canis y Malassezia pachydermatis. El tratamiento busca la eliminatión del comensal, aunque no son raras las recidivas. En esta revisión se discute la ecología de estos comensales potencialmente patógenos, con especial énfasis en la biologia cutánea y el ecosistema superficial. Se tienen en cuenta las estrategias para la supervivencia utilizadas por los microorganismos y los mecanismos de defensa del huésped. La enfernedad se desarrolla cuando la virulencia del comensal supera la resistencia del huésped. Se espera que el mejor conocimiento de la naturaleza compleja de la piel y de sus comensales llevará a un mejor conocimiento de las enfermedades asociadas a los comensales y, consecuentemente, a un tratamiento más efectivo. [Mason, I. S., Mason, K. V., Lloyd, D. H. A review of the biology of canine skin with respec...

Development of a real-time PCR to detect Demodex canis DNA in different tissue samples

“…D. canis is considered to be a normal inhabitant of canine skin and the disease is thought to be the consequence of a genetically mediated specific immunodeficiency that allows the proliferation of the Demodex mites (Greve and Gaffar 1966;Mason et al 1996;Scott et al 2001;It et al 2010). Destruction of the hair follicles, the subsequent inflammatory reaction and secondary infection with Staphylococcus pseudointermedius are the causes of severe lesions in affected dogs (Gafaar 1974;Scott et al 2001).…”

Response to Malassezia pachydermatis by peripheral blood mononuclear cells from clinically normal and atopic dogs

“…2 However, when found in high numbers from the skin of inflamed or seborrheic skin, the term Malassezia dermatitis (MD) is applied. 1,3,4 The distinct and predictable response to antifungal chemotherapy, which ameliorates much of the pruritus and erythema associated with MD, must often be repeated for recurrent infections in predisposed dogs. Because of potential toxicity associated with such treatment, other methods of treatment or prophylaxis are needed.…”

“…1 Although the organism is easily cultured from the noninflamed skin of clinically normal dogs, it is quite difficult to identify by cytologic techniques (direct impression smear, cotton-tip swab, dry skin scrapings) from the same dogs. 2 However, when found in high numbers from the skin of inflamed or seborrheic skin, the term Malassezia dermatitis (MD) is applied.…”

Investigation of bacterial and fungal agents from cutaneous lesions in canine Leishmaniasis

“…The secondary deficiency of specific immunity may lead to deep infectious pyoderma in dogs, and CVL is a good example for occurrence of these types of bacterial and mycotic skin lesions (Mason et al, 1996;Ciaramella et al,1997). The aim of this study was to identify the infectious agents that arise in cutaneous skin lesions in dogs with CVL.…”