Candida infections are the most common fungal infections in the world. These are yeasts, a fungus that exists primarily in the unicellular form. There are over 150 species but only about 10 are regarded as important human pathogens.
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DISEASE ASSOCIATIONS CHARACTERIZATION Immunosuppression
PATHOGENESIS CHARACTERIZATION Habitat Can be recovered from nearly every setting including soil, food, and hospitals
Normal commensal organism on mand
Transmission Majority of infections are endogenous but human-human transmission is possible Immune response
Intact integument is most important defense against invasion
Neutrophils and monocytes attack the invading organism-if these cells lack myeloperoxidase or the capacity to generate hydrogen peroxide and superoxide anion, Candida will not be destroyed
Lymphocytes play role in cell mediated immunity
IgG and humoral response play role in opsonizing organism
CHARACTERIZATION Laboratory Markers Culture media Grows well on routine blood agar and fungal media
Biphasic blood cultures and lysis centrifugation may facilitate recovery
CHARACTERIZATION General Species of primary human importance include:
C. stellatoidea (now C. albicans)
C. glabrata (formerly Torulopsis glabrata)
VARIANTS Thrush Esophagitis Nonesophageal, mucous membrane gastrointestinal candidiasis Vaginitis Cutaneous Candidiasis syndromes Generalized cutaneous candidiasis Erosio interdigitalis blastomycetica Candida folliculitis Candida balanitis Cutaneous lesions of disseminated candidiasis Intertrigo Paronychia and onychomycosis Diaper rash Perianal candidiasis Chronic mucocutaneous candidiasis Deep Organ Involvement CNS Respiratory tract Cardiac Candida endocarditis Urinary tract endocarditis Arthritis, osteomyelitis, costochondritis, myositis Peritonitis Hepatitis, gallbladder, and spleen Vasculitis Ocular Disseminated candidiasis
HISTOLOGICAL TYPES CHARACTERIZATION General Small thin walled ovoid cells (4-6 um) that reproduce by budding VARIANTS GIANT BLASTOCONIDIA
Giant blastoconidia of Candida albicans. A case report and review of the literature.
Alasio TM, Lento PA, Bottone EJ.
Department of Pathology, The Mount Sinai Hospital, New York, NY 10029, USA.
Arch Pathol Lab Med. 2003 Jul;127(7):868-71 Abstract quote
We describe a patient with extranodal non-Hodgkin lymphoma who developed systemic candidiasis after treatment with a cyclophosphamide-based chemotherapy regimen.
Histologically, the fungal organisms demonstrated markedly enlarged blastoconidia with a variety of morphologic forms, mimicking other mycotic organisms, such as Cryptococcus neoformans, Blastomyces dermatitidis, and Paracoccidioides brasiliensis.
The in vivo occurrence of such giant forms is rare, and when observed histologically may result in an erroneous diagnosis or a diagnosis of multiple mycotic organisms.
CHARACTERIZATION Special stains In tissue sections, standard PAS and GMS stains for fungus are adequate
- Evaluation of the use of Congo red staining in the differential diagnosis of Candida vs. various other yeast-form fungal organisms.
Department of Pathology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA.
- J Cutan Pathol. 2008 Jan;35(1):27-30. Abstract quote
The Congo red staining properties of Candida organisms in clinical tissue specimens have not, to the best of our knowledge, previously been reported.
The objective of this study was to determine if the Congo red staining characteristics of Candida vs. Histoplasma, Pityrosporum and Blastomyces could provide useful diagnostic information. Archival tissue specimens that contained Histoplasma, Pityrosporum, Candida and Blastomyces were stained with Congo red. The results of the Congo red staining were compared with the diagnoses which were originally rendered on the tissue.
Nine out of nine cases (100%) of Blastomyces were Gomori methenamine silver (GMS) positive and Congo red positive, seven out of seven cases (100%) of Histoplasma were GMS positive and Congo red negative, and eight out of eight cases (100%) that had Pityrosporum were GMS positive and Congo red positive; these results corroborate with previously described staining patterns for each respective organism. Nine out of nine cases (100%) that had Candida were GMS positive and Congo red negative.
Differential Congo red staining of Candida organisms can provide a rapid and accurate method of diagnosis in tissue specimens vs. Blastomyces and Pityrosporum, but not vs. Histoplasma.
PROGNOSIS AND TREATMENT CHARACTERIZATION Treatment
Dependent upon the site of the infection as well as the underlying immune status of the patient
Nystatin used for mucous membrane and cutaneous disease
Oral clotrimzaole and miconazole
Amphotericin B mainstay for disseminated and deep organ disease
Fluconazole may also be used
Macpherson and Pincus. Clinical Diagnosis and Management by Laboratory Methods. Twentyfirst Edition. WB Saunders. 2006.
Rosai J. Ackerman's Surgical Pathology. Ninth Edition. Mosby 2004.
Sternberg S. Diagnostic Surgical Pathology. Fourth Edition. Lipincott Williams and Wilkins 2004.
Robbins Pathologic Basis of Disease. Seventh Edition. WB Saunders 2005.
DeMay RM. The Art and Science of Cytopathology. Volume 1 and 2. ASCP Press. 1996.
Weedon D. Weedon's Skin Pathology Second Edition. Churchill Livingstone. 2002
Fitzpatrick's Dermatology in General Medicine. 6th Edition. McGraw-Hill. 2003.
Weiss SW and Goldblum JR. Enzinger and Weiss's Soft Tissue Tumors. Fifth Edition. Mosby Elesevier 2008
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Last Updated February 20, 2008
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