Sporotrichosis is a subacute or chronic fungal infection caused by the ubiquitous fungus Sporothrix schenckii. Disseminated cutaneous sporotrichosis is an uncommon entity and is usually present in the immunosuppressed. Here, a case of disseminated cutaneous sporotrichosis in an immunocompetent patient is reported. This 70-year-old healthy woman presented with multiple painful ulcerated nodules on her face and upper and lower extremities of 6-month duration, associated with low-grade fever, night sweats, loss of appetite, and loss of weight. Histopathological examination of the skin biopsy revealed epidermal hyperplasia and granulomatous inflammation in the dermis, with budding yeast. Fungal culture identified S. schenckii. She had total resolution of the lesions after 2 weeks of intravenous amphotericin B and 8 months of oral itraconazole. All investigations for underlying immunosuppression and internal organ involvement were negative. This case reiterates that disseminated cutaneous sporotrichosis, although common in the immunosuppressed, can also be seen in immunocompetent patients.
Sporotrichosis is a mycosis caused by a saprophytic dimorphic fungus named Sporothrix schenckii. Infections occur following traumatic inoculation of fungus from plants and infected cat bites and scratches. We report a case of a farmer who presented with a solitary subcutaneous nodule initially diagnosed as a soft tissue tumour. A history of agricultural activity and feline contact should draw the clinician's attention to sporotrichosis, as the diagnosis can be easily missed in atypical cases. The diagnosis, microbiology and management of the case are discussed.
We reviewed current literature on four different skin and subcutaneous infections which are often touted as 'emerging diseases' of south-east Asia, namely melioidosis, penicilliosis, sporotrichosis and Mycobacterium marinum infection. Lack of consensus treatment guidelines, high treatment costs and limited investigative capability in certain endemic areas are among the challenges faced by managing physicians. With the increase in borderless travelling, it is hoped that this review will facilitate better understanding and heighten the clinical suspicion of such infections for clinicians in other parts of the world.
Sporothrix schenkii is a dimorphic fungus that causes infections in both humans and animals. We report on 25 S. schenkii isolates collected in 2017 from humans and cats clinically diagnosed with sporotrichosis, in Malaysia. These isolates were phenotypically identified as S. schenkii sensu lato and further defined as S. schenckii sensu stricto based on partial calmodulin gene sequence. Isolates from both humans and cats were genotypically identical but displayed phenotypic variation. Phylogenetic analyses based on partial calmodulin sequence showed that the Malaysian isolates clustered with global S. schenkii sensu stricto strains, in particular, of the AFLP type E. This analysis also revealed that partial calmodulin sequence alone was sufficient for classifying global S. schenckii sensu stricto strains into their respective AFLP types, from A to E. The genetically conserved S. schenkii sensu stricto species isolated from humans and cats is suggestive of a clonal strain present in Malaysia. To the best of our knowledge, this is the first report on molecular identification of Sporothrix schenkii strains from human infections in Malaysia. Further studies are required in order to elucidate the clonal nature of Malaysian S. schenkii isolates. Our findings indicate the presence of a predominant S. schenkii genotype in the environment, causing infections in both cats and humans in Malaysia.
Epidemiological data on the aetiologic agents of feline sporotrichosis in Malaysia have not been reported, though human sporotrichosis in Malaysia is reported to be transmitted primarily via cat scratch. To the best of our knowledge, the present report is the first study of the molecular epidemiology of Sporothrix schenckii isolates from cats with sporotrichosis in Malaysia. In the present work, we characterised 18 clinical isolates from cats in Malaysia based on molecular properties, including sequence analyses of the calmodulin gene and the rDNA ITS region and selective PCR of mating type (MAT) loci. In this study, isolates from feline sporotrichosis were identified as a S. schenckii sensu stricto by sequence analyses of the calmodulin gene and the internal transcribed spacer (ITS) region. Notably, phylogenetic analysis of the ITS confirmed assignment to clinical clade D (and not C) of S. schenckii sensu stricto. Therefore, clinical clade D of S. schenckii sensu stricto appeared to be the prevailing source of feline sporotrichosis in Malaysia. The ratio of MAT1-1-1:MAT1-2-1 in these Malaysian isolates was found to be 1 : 0. This result suggested that a clonal strain of S. schenckii is the prevailing causative agent of feline sporotrichosis in Malaysia.
Sporotrichosis is a subcutaneous fungal infection caused by a thermally dimorphic aerobic fungus, Sporothrix schenckii. It results from traumatic inoculation or contact with animals. Most cases were reported mainly in the tropics and subtropics.
Feline sporotrichosis has been reported in Malaysia since the 1990's. Since then, studies have revealed that clinical clade D, Sporothrix schenckii sensu stricto, of a single clonal strain is the most common cause of this disease in Malaysia. The prevalence of a single clonal strain from a clinical clade was never before reported in Asia in a specific geographical niche. This raises the possibility of a process of purifying selection and subsequent clonal proliferation. While agricultural practices may serve as the selective pressure, direct causality has yet to be established. Studies into the thermo-tolerability of the Malaysian clonal strain of S. schenckii sensu stricto revealed that a small minority of clinical isolates have the capacity to grow at 37℃, while the majority displayed low susceptibility to commonly used antifungals in clinical practice, such as itraconazole (ITZ) and terbinafine (TRB). Despite unestablished breakpoints, suspected resistance (MIC > 4 mg/mL) towards amphotericin B (AMB) and fluconazole (FLC) was recorded in the isolates. This explains the often lack of clinical response in feline patients treated with recommended doses of antifungals, including ITZ. Coupled with the potential zoonotic transmission to clients and veterinarians, protracted treatment period, and subsequent cost of treatment, prognosis of feline sporotrichosis is often regarded to be poor. The use of a higher dose of ITZ has been reported, and an adoption of this high-dose treatment regime is reported in this manuscript, with complete cure achieved in cases of recalcitrant and/or unresponsive feline sporotrichosis, which would otherwise be euthanized.