Frequency, Body Distribution, and Population Size of Malassezia Species in Healthy Dogs and in Dogs with Localized Cutaneous Lesions

Abstract

Abstract. Malassezia species are commensal organisms of human and animal skin that occasionally act as opportunistic pathogens. The lipid-dependent species are associated with human skin disorders, whereas the non-lipid-dependent species (Malassezia pachydermatis) is considered as an opportunistic secondary pathogen affecting the canine skin surface and ear canal. This study evaluated the relationship between Malassezia yeasts, their population size, and the occurrence of skin lesions from healthy and skin-diseased dogs. The efficiency of cytological examination and fungal culture for Malassezia detection was also evaluated. From March 2002 to July 2003, 33 healthy dogs and 54 dogs with pruritic localized skin diseases were examined; skin swabs (1218) were collected from 7 anatomical sites for culture and cytological examination. Malassezia prevalence according to anatomical site and the agreement between cytological results and fungal cultures were statistically analyzed. Differences in mean colony forming unit counts between positive healthy and diseased dogs were evaluated using the Bonferroni test for post hoc pair-wise comparisons. In healthy dogs, Malassezia yeasts were most frequently isolated in the perianal and perioral areas. The frequency of isolation and population size of Malassezia species were higher in dogs with localized dermatitis, especially in affected areas, indicating a role for Malassezia in the occurrence of skin lesions. Malassezia pachydermatis was the species most commonly cultured from the skin and external ear canal of healthy and diseased dogs; isolation of lipid-dependent yeasts from healthy dogs was less frequent. Using fungal culture as the gold standard, cytological examination showed good relative specificity (95%) but very low relative sensitivity (30%).

MalasseziaversusCandidain Healthy Dogs

“…In general, Malassezia yeasts are associated with the skin and mucous membranes in healthy and diseased dogs [9,10,22,30,31]. Even 62.9 % of the dogs are positive for Malassezia yeasts.…”

Malassezia spp on the periocular skin of dogs and their association with blepharitis, ocular discharge, and the application of ophthalmic medications

“…In the present study, cytologic evaluation identified Malassezia spp in 4 of 28 (14%) periocular samples obtained from eyes with blepharitis and 15 of 139 (11%) samples obtained from eyes without blepharitis. Because Malassezia spp were identified by fungal culture in that other study 3 and cytologic evaluation in the present study, the results of the 2 studies cannot be directly compared. Despite the fact that fungal culture is a more specific and sensitive method for identification of Malassezia spp than is cytologic evaluation, 3 we chose to use cytologic evaluation in the present study because it is used routinely in clinical practice and is easier to perform and less expensive than is a fungal culture.…”

“…3 Results of other studies 2,3 indicate that the likelihood of detection of Malassezia spp on the skin of dogs varies with the location of skin sampled, method used to detect the organism, and disease status of the patient. In the only other study 3 that assessed the frequency of Malassezia spp detection on the periocular skin of dogs, the organism was identified by fungal culture of swab specimens of the periocular area in 3 of 33 (9%) healthy dogs and 24 of 54 (44%) dogs with pruritic cutaneous lesions at various anatomic locations; however, it is unclear how many of those dogs with pruritic lesions were affected in the periocular region. In the present study, cytologic evaluation identified Malassezia spp in 4 of 28 (14%) periocular samples obtained from eyes with blepharitis and 15 of 139 (11%) samples obtained from eyes without blepharitis.…”

“…3 In the study 3 that used culture as a means to identify Malassezia spp, the perianal area was the area most frequently colonized (20/33 [61%]), the inguinal area was the area least frequently colonized (1/33 [3%]), and Malassezia spp were cultured from the periorbital region of 3 of the 33 (9%) healthy study dogs. To our knowledge, studies have not been conducted in which the frequency of Malassezia colonization of the periocular region of healthy dogs was determined by cytologic examination.…”

Antimicrobial effects of topical skin cream containing natural oil mixtures against Staphylococcus pseudintermedius and Malassezia pachydermatis

“…Staphylococcus pseudintermedius and Malassezia pachydermatis are the most common pathogens isolated from pyoderma and otitis externa in dogs (Cafarchia et al 2005;Fitzgerald 2009). In the last decade, resistance to antimicrobial agents has increased, particularly with the emergence and widespread dissemination of methicillin-resistant S. pseudintermedius in dogs as a result of the broad use of certain antimicrobial agents (Neu 1992;Kadlec and Schwarz 2013).…”