Acremonium species: Introduction, Morphology, Pathogenecity, Lab Diagnosis and Treatment
Introduction of Acremonium species
Acremonium species are on SDA as shown above picture. Species of this genus are commonly found in soil, decaying vegetation, and decaying food.
Morphology
Acremonium species are slow growers and colonies are often compact and moist at first, becoming powdery, suede-like, or floccose with age. Colonies may be white, grey, rose, pink, or orange in color. Hyphae are fine and hyaline and produce mostly simple awl-shaped erect phialides. There is the occurrence of ameroconidia ( one-celled conidia), hyaline or pigmented, globose to cylindrical, and mostly aggregated in slimy heads at the apex of each phialide.
Pathogenicity
Acremonium has long been recognized as an etiologic agent of the nail and corneal infection, mycetoma, peritonitis and dialysis fistulae infection, osteomyelitis, meningitis following spinal anesthesia in a normal person, cerebritis in an intravenous drug abuser, endocarditis in a prosthetic valve operation, and pulmonary infection in a child. Occasional deep Acremonium infections have been reported in patients with serious underlying medical conditions.
Medically important Acremonium species reported are-
- A. alabamensis,
- A. falciforme
- A. kiliense,
- A. roseogriseum,
- A. strictum,
- A. potroni and
- A. recifei.
Laboratory Diagnosis
Laboratory procedures in diagnostic mycology are directed mainly towards:
- Microscopy: Direct demonstration of the pathogenic fungi in clinical
specimens e.g. KOH mount - Culture: Successful isolation of pathogenic fungi and fungal elements observation through LPCB preparation
- Serology and molecular test: Supportive evidence of specific fungal infection (antigen, antibody, cell wall markers such as ß 1-3 Glucan and metabolite detection). However, PCR for the detection of fungal DNA is yet to be validated for routine diagnosis of any fungal infection.
- Antifungal susceptibility(AFST): Prediction of possible therapeutic outcome
- Epidemiology: Tracing the source of infection
Treatment
Following antifungal drugs are useful to treat this fungal infection-
- Itraconazole
- Posaconazole
- Voriconazole
- Amphotericin B
- Caspofungin
- Anidulafungin
Keynotes
- Microconidial Fusarium isolates may be confused with Acremonium, but they usually grow faster and have colonies with a characteristic fluffy appearance.
- Acremonium having typical characteristics- hyphomycetes with solitary, erect, hyaline, awl-shaped phialides producing single-celled. globose to cylindrical conidia, mostly in slimy heads.
Bibliography
- Rippon’s JW: Medical Microbiology. The pathogenic fungi and the Pathogenic Actinomycetes. 3rd ed 1988 Publisher WB Saunder co, Philadelphia.
- Clinical Microbiology Procedure Handbook, Chief in editor H.D. Isenberg, Albert Einstein College of Medicine, New York, Publisher ASM (American Society for Microbiology), Washington DC.
- Medical Mycology. Editors: Emmons and Binford, 2nd ed 1970, Publisher Lea and Febiger, Philadelphia.
- A Textbook of Medical Mycology. Editor: Jagdish Chander. Publication Mehata, India.
- Practical Laboratory Mycology. Editors: Koneman E.W. and G.D. Roberts, 3rd ed 1985, Publisher Williams and Wilkins, Baltimore.
- https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/acremonium