Key 6:Blood culture gram stains in
the context of Biofire BCID and
Nanosphere Verigene
At the end: Automated processors,
automated stainers, acridine orange
stain information
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Fast gram stain report = less death!
Am J Clin Pathol 2008:130:870-876
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If you have the ID faster?
• What tool can the physician use to treat the
patient in a more focused way?
– ___________________
• Are there any outcome studies comparing
patients who got BCID or Verigene versus only
Gram stain?
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Questions
• Do you call only the gram, or only the PCR, or
both to the floor?
• Do you only run molecular once per patient?
• How soon do you run again if patient has
more positives?
• Do you repeat molecular if growth does not
match molecular results?
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More questions
• Do you run only MRSA/MSSA if only GPC clusters
seen?
• Do you run molecular if blood culture instrument
says positive but gram stain is no organisms seen?
• Do you run molecular if only GPR seen?
– Since Listeria is so rare!
• Do you always sub positive blood cultures to the
same media?
• Or do the gram stain and/or molecular tests change
the medias to which you sub the bottles?
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Cepheid GeneXpert MRSA/MSSA
• MRSA
• MSSA
• If neither, then some kind of CNS, but could be
anaerobic GPC such as Finegoldia magna, or
could be S. lugdunensis
• Or could be a combination!
• Immediate impact, at least on day shift:
– _______________________
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Questions to ask:
• How long did it take for bottle to turn
positive?
– Watch out for the 3-5 day incubation positives
– Some examples on next slides
• Only anaerobic bottles are positive?
• Only aerobe bottles are positive?
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What to report when no targets detected?
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“No targets detected”
• We know what that means.
• Does the doctor know what that means?
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No targets detected
Reported as NOS all weekend long x 3!
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No targets detected
Reported as yeast
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Morphed into this
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No targets detected
160
One target detected, but two bugs?
161
No targets detected
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References
• Barenfanger, J, Drake, C. Interpretation of Gram Stains for the
Nonmicrobiologist. Laboratory Medicine July 2001, number 7, volume 32
• Dallas, S. D. “Gram Stain Errors”. ASCP TechSample Series, Generalist No.
G-12 2004, ASCP Press, 2004.
• Rand, K. and Tillan, M. Errors in Interpretation of Gram Stains from
Positive Blood Cultures, Am J Clin Pathol 2006: 126: 686-690
• Munson, E., Block, T., Basile, J., Hryciuk, J., Schell, R. Mechanisms to
Assess Gram Stain Interpretation Proficiency of Technologists at Satellite
Laboratories, J Clin Micro, Nov 2007 3754-3758
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Supplemental Things
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Robo-grammer: COPAN WASPLab
• https://www.youtube.com/watch?v=Tp9TTVw
YfZg
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Robo-grammer: BD Kiestra WLA
• http://www.bd.com/scripts/europe/labautomation/productsdrilldown.asp
?CatID=455&SubID=1836&siteID=20309&d=&s=europe%2Flabautomation
&sTitle=Lab+Automation&metaTitle=Total+Lab+Automation&dc=europe&
dcTitle=Europe
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BioMerieux Previ Isola
• Automated plating but no Gram stains
• http://www.biomerieux-usa.com/clinical/previisola/?gclid=CKrNjoq348cCFQENaQod5EQJOA
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AGS-1000
• AGS-1000, Quick Slide, GG & B company
• One slide at a time 3-5 minutes each
• Good for a small stat lab
• https://www.youtube.com/watch?v=XuXoqVgjbWU
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MGS-80
•
•
•
•
https://www.youtube.com/watch?v=srqBhxcVCcU
80 slides an hour.
Batch or single stat slide
Offer 1 year subscription to Gram stain training
course
Hardy Diagnostics bought this company in May, 2016
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Biomerieux Previ Color Gram
https://www.youtube.com/watch?v=BdE47TTue9I
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ELITech Aerospray Gram
• Combines cytocentrifuge
• https://www.youtube.com/watch?v=Lwl6XpDt
ztE
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When in doubt: Acridine Orange?
•
•
•
•
•
•
•
Faster than Gram stain but need fluorescent scope.
Air dry, methanol fix, air dry
AO stain 2 minutes
Rinse well
Air dry, protect from light
Use FITC filter, View on low, then oil
Use type F low fluorescence oil
• Can remove oil with xylene and gram stain the very same slide,
right over the AO
• Can do AO wet mount, one drop of specimen, one microliter of
stain and coverslip
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Acridine Orange
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What is AO good for?
•
•
•
•
•
Positive blood culture bottles when the Gram stain is negative
Vitreous fluid, bug or pigment granule?
Bloody wounds, is it a bug or an artifact?
Mycoplasma suspected
Done correctly, human cells are green, bacteria are orange
http://www.scionpublishing.com/shop/ProductImages/1.JPG
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Mini-review of AO technique
• http://ki.se/sites/default/files/goran_kronvall
_ao_staining_mini-review.pdf
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