Article

Rhinocladiella mackenziei as an emerging cause of cerebral phaeohyphomycosis in Pakistan: a case series.

Department of Pathology/Microbiology, Aga Khan University Hospital, Stadium Road, Karachi, Pakistan.
Clinical Infectious Diseases (Impact Factor: 9.42). 01/2011; 52(2):213-7. DOI: 10.1093/cid/ciq114
Source: PubMed

ABSTRACT Six cases of Rhinocladiella mackenziei cerebral phaeohyphomycosis are being reported for the first time in Pakistan. Identification was confirmed by DNA sequencing (isolates and fixed tissue). Diabetes, head trauma, immunosuppressive treatment, and postpartum state were present in 4 cases. Two survivals and 3 fatalities occurred, with 1 patient lost to follow-up.

Full-text

Available from: Bushra Jamil, Jun 12, 2015
0 Followers
 · 
134 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The dematiaceous fungi are usually defined as those that have melanin or melanin-like pigment in the wall of the hyphae and/or spores and can cause a variety of infections in humans known as phaeohyphomycosis (phaeo is Greek for "dark"). Over 100 species and 60 genera of dematiaceous, or pigmented fungi have been implicated in human diseases. The vast majority are filamentous fungi or moulds, though a few yeast species are also important pathogens. Though they represent a very heterogeneous group of fungi, the distinguishing characteristic common to all these various species is the presence of melanin in their cell walls, which imparts the dark colour to their conidia or spores and hyphae. The colonies are typically brown to black in colour as well. Dematiaceous fungi are generally found in soil or associated with plants and distributed worldwide. Those causing the specific conditions of mycetoma and chromoblastomycosis are primarily found in tropical regions. Exposure is thought to be from inhalation or minor trauma, which may not even be noticed by the patient. The taxonomy and nomenclature of dematiaceous fungi undergo constant revision and are controversial. Thus, a single organism may be identified by a variety of names in the recent and historical literature, a circumstance that contributes to confusion for clinicians and for all but the most dedicated mycologists. This monograph does not attempt to deal definitively with the difficult questions of mycological classification and nomenclature of dematiaceous fungi, but alternative names or appropriate synonyms will be given in each case. Identification of these fungi is based mostly upon morphology. Important structures include annellides (Phaeoannellomyces, Exophiala), phialides (Phialophora, Wangiella), adelophialides (Phialemonium without collarettes, Lecythophora with collarettes), differentiation of conidiophores (Cladosporium) and conidial hilum, septation and germination (Bipolaris, Drechslera, Exserohilum). A variety of infectious syndromes are attributed to dematiaceous fungi Two unique conditions, mycetoma and chromoblastomycosis, are caused by a small number of species and are usually seen in tropical regions. • Mycetoma is commonly associated with chronic swelling and draining sinus tracts, usually of the lower extremities. It can be debilitating and difficult to treat. • Chromoblastomycosis often presents with verrucous lesions that may occur anywhere on the body, but usually on the lower extremities. This is a chronic, slowly progressive subcutaneous mycosis. Minor trauma typically precedes the lesions. Initially, nodular lesions are present, which may progress over years to form large, verrucous plaques. • Phaeohyphomycosis is a term that encompasses many clinical syndromes due to a wide variety of fungi. Conditions include superficial infections such as keratitisand subcutaneous nodules, allergic diseases, and invasive infections such as brain abscess and disseminated disease. Relatively little is known regarding the pathogenic mechanisms by which many of these fungi cause disease, particularly in immunocompetent individuals. One of the likely candidate virulence factors is the presence of melanin in the cell wall, which is common to all dematiaceous fungi. There are several mechanisms proposed by which melanin may act as a virulence factor : • It is thought to confer a protective advantage by scavenging free radicals and hypochlorite that are produced by phagocytic cells in their oxidative burst that would normally kill most organisms. • Melanin may bind to hydrolytic enzymes, thereby preventing their action on the plasma membrane.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A review is given of melanized fungi involved in human infection, including species forming budding cells and strictly filamentous representatives. Classically, they are known as "phaeoid" or "dematiaceous" fungi, and, today, agents are recognized to belong to seven orders of fungi, of which the Chaetothyriales and Pleosporales are the most important. Infections range from cutaneous or pulmonary colonization to systemic or disseminated invasion. Subcutaneous involvement, either primary or after dissemination, may lead to host tissue proliferation of dermis or epidermis. Particularly in the Chaetothyriales, subcutaneous and systemic infections may occur in otherwise apparently healthy individuals. Infections are mostly chronic and require extended antifungal therapy and/or surgery.
    Cold Spring Harbor Perspectives in Medicine 11/2014; DOI:10.1101/cshperspect.a019570 · 7.56 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cerebral phaeohyphomycosis (CP) is a very rare but serious form of central nervous system fungal infection that is caused by dematiaceous fungi. It is commonly associated with poor prognosis irrespective of the immune status of the patient. In this study, the authors describe the first case of CP in Korea that occurred in a 75-year-old man without immunodeficiency and showed favorable outcome after surgical excision and antifungal therapy. In addition, the authors herein review the literature regarding characteristics of this rare clinical entity with previously reported cases.
    Journal of Korean Neurosurgical Society 11/2014; 56(5):444-7. DOI:10.3340/jkns.2014.56.5.444 · 0.52 Impact Factor