Human and animal isolates of Pseudallescheria boydii and Scedosporium species, from Melbourne, Australia, 1977–1995

Abstract

From 1977 to 1995, 25 of the fungal cultures referred to the Microbiological Diagnostic Unit Public Health Laboratory at The University of Melbourne, Victoria, Australia were identified as Scedosporium apiospermum, Pseudallescheria boydii, or Scedosporium prolificans. These cultures had been isolated from 22 patients at metropolitan hospitals and three animals at Veterinary Institutes. Eight of the human isolates were identified as P. boydii, 11 as S. apiospermum and three as S. prolificans. Isolates of S. apiospermum and P. boydii were from localised infections in immunocompetent patients, after trauma in two cases; from the lungs of patients with predisposing pulmonary disorders, such as cystic fibrosis or mycobacterial infection; and from immunocompromised patients with haematological malignancies or after heart, lung or heart/lung transplantation. Scedosporium prolificans isolates were from immunocompromised patients, one of whom had received a heart transplant, another had HIV infection and the third suffered with acute myelogenous leukaemia and died with disseminated infection. An isolate from the vaginal discharge of a horse with an infected uterus was identified as S. apiospermum. Isolates from aseptically collected milk samples from a goat and a cow with histories of mastitis, were identified as P. boydii. This study records the spectrum of infections caused by these opportunistic fungal pathogens in Melbourne from 1977 to 1995.

DisseminatedScedosporium prolificansinfection in a German Shepherd dog

“…Ultimately, most human cases of disseminated S. prolificans are fatal 1–5,10–12 and the clinical course in this case was similar. Diagnosis is more likely if urine or tissue samples are cultured in suspected cases, but the uniformly poor response of S. prolificans to antifungal therapy suggests a grave prognosis for infected dogs.…”

“…Although there have been no reports of disseminated S. prolificans infections in dogs in Australia, there have been many reports describing the disease in human patients, 1–4,12,27 a proportion of whom have resided in Melbourne 4,12 . The use of semi‐selective media, such as SceSel+ 28 or dichloran rose Bengal chloramphenicol medium (Oxoid, UK) supplemented with benomyl, 7 is considered mandatory for the isolation of Scedosporium spp.…”

“…Scedosporium prolificans was initially isolated from greenhouse soil in 1974 9 and later reported as a human and animal pathogen in 1984 5 . Since the first reported cases, there has been an increase in published cases of both localised and disseminated S. prolificans infections in both immunocompetent and immunocompromised human patients throughout the world, including Australia 1–5,10–12 . In humans, S. prolificans infections are associated with marked morbidity and mortality because of resistance to almost all systemic antifungal agents at non‐toxic doses and the rapid clinical course in disseminated infections 1,13,14 .…”

Ultrasonography of a ureteral and bladder fungal granuloma caused byScedosporium apiospermumin a basset hound

“…Scedosporium infection in other animal species has been documented including cats, 2 horses, 3-5 layer pullets, 6 cows, 7 and humans. 8 In dogs, Scedosporium species have been previously documented causing keratomycosis, 9,10 discospondylitis, 11 osteomyelitis, 12,13 disseminated disease, 13 and rhinitis. 14,15 Granuloma formation has been documented in a dog's nasal cavity, 16 gastrointestinal tract, 17 and in the abdomen secondary to evisceration.…”

Epidemiology of Scedosporiosis

“…Scedosporiosis has been reported in patients with advanced human immunodeficiency virus (HIV) infection [52,53] haematological malignancy [5, 8•, 21] and primary immunodeficiency disorders, particularly chronic granulomatous disease (CGD) [54,55]. Patients with haematological malignancy are more likely to be neutropenic at the time of diagnosis of scedosporiosis and more likely to present with fungaemia due to L. prolificans and disseminated disease [8•, 21].…”