Assessing the relationship between Malassezia and leishmaniasis in dogs with or without skin lesions

The relationship among the frequency, population size and phospholipase activity of Malassezia pachydermatis was investigated for dogs with Leishmania infantum infection (Li+) and those without evidence of this infection (Li−). A group of 188 dogs (141 without and 47 with skin lesions) was examined clinically, and samples were taken for the detection of Malassezia and L. infantum using various diagnostic methods. Malassezia was cultured from skin samples from 101 (53.7%) dogs and classified biochemically and molecularly as M. pachydermatis. A significantly higher mean population size of M. pachydermatis was cultured from the skin of L+ dogs compared with L− dogs. For M. pachydermatis, most phospolipase-producing cultures and the highest phospholipase activity were recorded for L− dogs with lesions and L+ dogs without lesions. The results showed that M. pachydermatis was a common commensal on dogs with or without L. infantum infection and established that L. infantum infection in dogs without skin lesions was associated with increased growth of M. pachydermatis and production of phospholipase in vitro.