Malassezia pachydermatis carriage in dog owners

Abstract

Yeasts of the genus Malassezia serve as both commensal microorganisms and pathogens on the skin of humans and domestic animals. Although rare, cases of life-threatening fungemia in people have been attributed to Malassezia pachydermatis, for which dogs are a natural host. Zoonotic transfer has been documented from dogs to immunocompromised patients by healthcare workers who own dogs. We investigated the role of pet dogs as risk factors for mechanical carriage of M. pachydermatis on human hands. Dogs and their owners were sampled as pairs, by fungal culture and nested polymerase chain reaction (PCR). Although fungal culture was not a reliable means by which to detect carriage of the yeast on human hands, PCR identified M. pachydermatis on most (approximately equal to 93%) human participants. Human carriage of ubiquitous opportunistic pathogens such as M. pachydermatis underscores the importance of good hand hygiene by healthcare professionals.

Figure 1

Rates of detection of Malassezia pachydermatis on canine and human skin by 2 laboratory techniques. A normal group of dogs and a group known to harbor M. pachydermatis infection, paired with their respective owners, are represented. NS, nonsignificant; PCR, polymerase chain reaction.

Figure 2

Comparison of rates of detection of Malassezia pachydermatis on the hands of dog owners by 2 laboratory techniques. NS, nonsignificant; PCR, polymerase chain reaction.