microscopic observation and culture of aspergillus species: the traditional way nancy mcclenny, mpa,...
TRANSCRIPT
Microscopic Observation and Culture of Aspergillus species:
The Traditional Way
Nancy McClenny, MPA, CLS/MTAssociate Program Director, CLS Internship Program,
San Francisco State UniversitySan Francisco, CA
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What’s the Role of the Clinical Laboratory?
• Who is a Clinical Laboratory Scientist (CLS)?
• Are microscopy and culture still the methods of choice for fungi?
• Who will do the work?
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Diagnostic Specimen for Fungus
Pathology
Fungal stainsImmunodiagnostics
Clinical Laboratory
Gram stainWet mount (KOH) CultureSerology
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What fungus is shown in this Gram stain?
Hyphaeseptate, 45°
branching
Septum
cmazzanti, CMVL,Stanford
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Microscopy in the Clinical Lab: The Critical Tools
• Fluorescent dye with KOH– Blankophor– Calcofluor– Uvitex 2B
• Calibrated micrometer
• Expert readers!
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How do we know it’s Aspergillus?
Accessory conidia
A. niger A. terreus
Stipe
Stanford Medical Center Wiley Schell, Duke Univ.
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How do we know it’s NOT Aspergillus?
Phialide
Phialoconidium
Fusarium species
Annelloconidia
Scedosporium apiospermum
Wiley Schell, Duke Univ. Stanford Medical Center
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How do we know it’s NOT Aspergillus?
Dactylaria gallopava
Methenamine Silver KOH
Stanford Medical Center
Dematiaceous hyphae
Stanford Medical Center
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Stipes of A. niger, not hyphae of Mucor.
Conidia of A. niger,
not Candida
Wiley Schell, Duke Univ.
Why do we need culture?
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How can culture for Aspergilli be improved?
• Sporulation media for primary isolation
• Incubation at both 35-37°C and 30°C.
• Daily inspection of cultures
• Microaerophilic environment(Tarrand, Kontoyiannis, and Han. Abstract M-909, 42nd ICAAC, 2002.)
A. versicolor onSabouraud Agar
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A. versicolor on Potato Dextrose Agar
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Poorly sporulatingA. fumigatus
Unusual or Atypical Isolates
nmcclennyNeosartorya fischeri with
masses of cleistothecia
nmcclennynmcclenny
15Aspergillus terreus Jharris, Texas Dept. of Health
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Phenotypic Identification of Other Aspergillus Species
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Who Will Do the Work?
•A 53-56% reduction in CLS training programs in the past 12 years
•34% of professionals in microbiology laboratories 50 years old
Available at: http://www.asm.org/Policy/index.asp?bid=28422
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Case Study CLS Internship Program
S. F. State University
• April, 2004: $10.3 million is cut.• CLS Internship Program must
become self-supporting.• August 2004: Director accepts a job
offer outside of SFSU.• September, 2004: CLS program is
suspended.