Granulomatous lymphadenitis caused by Talaromyces helicus in a Labrador Retriever

Abstract

A 3-year-old spayed female Labrador Retriever was presented for right prescapular lymphadenomegaly. Examination of fine-needle aspirates and impression smears of the node revealed many short hyphal structures found within macrophages and extracellularly. Hyphae were approximately 3 μm in diameter, were irregularly septate with nonparallel walls, and had a small clear halo surrounding a partially stained basophilic internal structure. Hyphae were tapered on one end and had oval to pyriform swellings of 7-10 μm on the other, resulting in a bulbous appearance. Fungal elements stained positively with Gomori methenamine silver and Periodic acid-Schiff stains. The dog was euthanized at the owner's request, and necropsy revealed marked peripheral and visceral lymphadenomegaly. Histopathologic examination of lymph nodes confirmed granulomatous lymphadenitis with many fungal hyphae. Fungal culture yielded pure cultures of organisms that failed to produce ascospores or conidia precluding morphologic identification. PCR was performed using pan-fungal primers, ITS-1 and ITS-2, to amplify the intergenic spacer regions of ribosomal RNA; the PCR product was sequenced and a BLAST search of the GenBank databases at NCBI revealed 100% identity of the organism with Talaromyces helicus, the sexual form of Penicillium helicum. Talaromyces helicus has not previously been reported to cause disease in people or animals.

Cytologic identification of fungal arthritis in a Labrador Retriever with disseminated Talaromyces helicus infection

“…A single previous veterinary report describes extensive granulomatous lymphadenitis secondary to T helicus in a young adult Labrador Retriever . In addition to the involvement of many peripheral and visceral lymph nodes, rare foci of inflammation, and fungal organisms were identified within the liver on postmortem examination . Time from diagnosis to euthanasia was swift due to development of lethargy and inappetence …”

New Talaromyces species from indoor environments in China

“…Other medically important Talaromyces species including T. indigoticus , T. piceus , T. indigoticus , T. helicus , T. rugulosus , T. purpurogenus , T. radicus and T. verruculosus have been reported in superficial or disseminated, fatal infections (Neuhann, 1976, Swietliczkowa et al., 1984, de Hoog et al., 2000, Horré et al., 2001, Santos et al., 2006, de Vos et al., 2009, Weisenborn et al., 2010, Tomlinson et al., 2011). Among the nine new species described here, T. adpressus , T. beijingensis , T. diversiformis , T. fusiformis and T. reverso-olivaceus grow well at 37 °C, thus are more risky for human health.…”

Successful treatment of intra‐abdominal eumycotic mycetoma caused by Penicillium duponti in a dog

“…is a common contaminant of body and mucosal surfaces and is considered an opportunistic pathogen (Greene 2012). In immunosuppressed dogs, it can cause disseminated disease (Tomlinson et al 2011, Caro-Vadillo et al 2007, Kano et al 2006, Murphy et al 2011.…”