the cytology-radiology-surgical pathology model for gram stains
the cytology-radiology-surgical pathology model for gram stains
the cytology-radiology-surgical pathology model for gram stains
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GRAM STAIN<br />
SMEAR INTERPRETATIONS<br />
THAT IMPROVE PATIENT CARE<br />
Richard (Tom) Thomson, Jr., Ph.D., D(ABMM), FAAM<br />
Evanston Hospital<br />
NorthShore University HealthSystem<br />
University of Chicago Pritzker School of Medicine<br />
rthomson@northshore.org
Multiple Urinary Tract Infections in<br />
and Elderly Male<br />
• Emergency Department Visit<br />
– 70 yo male with fever 101.6 o F<br />
– PMH includes 3 admissions <strong>for</strong> UTI in past 2 months<br />
– WBC 12,000 (87% PMN’s)<br />
– UA positive LE and Nitrites<br />
– Blood and midstream urine <strong>for</strong> culture collected<br />
– Admitted with <strong>the</strong> diagnosis of UTI<br />
– Levofloxacin IV
Urinary Tract Infection<br />
in an Elderly Male<br />
• Culture Report:<br />
50,000-100,000 CFU/ml E. coli<br />
• Gram Stain Report:<br />
4+ PMN’s<br />
4+ Mixed Urogenital Flora<br />
Gram stain reviewed and verified
Urinary Tract Infection<br />
in an Elderly Male<br />
• Culture Report:<br />
50,000-100,000 CFU/ml E. coli<br />
• Gram Stain Report:<br />
4+ PMN’s<br />
4+ Mixed Urogenital Flora<br />
Gram stain reviewed and verified<br />
Comment: Gram stain reviewed by Dr Thomson. The<br />
presence of PMN’s, bacterial morphologies<br />
resembling mixed colon flora and fecal debris<br />
suggests a vesico-colic fistula.
Questions, Answers and Topics<br />
• How has <strong>the</strong> Gram stain changed?<br />
• Is it still working?<br />
• Should <strong>the</strong> Gram stain be standardized?<br />
• Level I reporting (minimum competency) needed by<br />
all who “read” Gram <strong>stains</strong><br />
• Level II reporting <strong>for</strong> senior technologists and<br />
supervisors<br />
• Level III Interpretations <strong>for</strong> laboratory directors<br />
(medical microbiologists)
Questions, Answers and Topics<br />
• Pattern recognition of specific diseases<br />
– Case studies in Gram Stain Interpretations<br />
– Examples of interpretations that make a difference in<br />
patient care<br />
• How to make Gram stain reporting relevant in <strong>the</strong><br />
future
HOW TO STANDARDIZE THE<br />
GRAM STAIN PROCEDURE<br />
• Selecting a portion of <strong>the</strong> specimen<br />
• Preparing <strong>the</strong> smear<br />
• Low power (10X) examination<br />
• High power (100X) examination<br />
• Quantitation of cells and microorganisms<br />
• Examination and reporting based on specimen type<br />
• Slides <strong>for</strong> review
Selecting a Portion of <strong>the</strong> Specimen
PREPARING THE SMEAR<br />
Make a monolayer of cells
PREPARING THE SMEAR<br />
Concentrating fluids using a cytospin
LOW POWER (10X) EXAMINATION<br />
10-20 fields, quantitate cells<br />
select area <strong>for</strong> high power examination
HIGH POWER (100X) EXAMINATION<br />
20-40 fields, confirm cells, quantitate microorganisms
GRAM STAIN QUANTITIES<br />
• 1+ (very rare)<br />
– Less than 10 in all fields examined<br />
• 2+ (few)<br />
– More than 10 in all fields but less than 1/field<br />
• 3+ (moderate)<br />
– More than 1/field but less than 25/field<br />
• 4+ (many)<br />
– More than 25 in one field<br />
• 1-3+ versus 1-4+ quantities??
Staining Procedure to Standardize<br />
• Standard <strong>gram</strong> stain reagents and method to<br />
establish a normal against which variations<br />
can be compared<br />
– Fixation (heat v alcohol)<br />
– Dyes and concentrations<br />
– Decolorizer<br />
– Times
GRAM STAIN REPORTING<br />
BASED ON SPECIMEN SOURCE<br />
• Sterile fluid or tissue (presumed)<br />
– Report PMN’s<br />
– Report all microorganisms<br />
– > 3 morphologically typical shapes be<strong>for</strong>e reporting<br />
• Non-Sterile specimen source<br />
– Report PMN’s<br />
– “Name” microorganisms only if potential pathogen<br />
– Quantitate and report “normal flora”
SLIDES FOR REVIEW
GRAM STAIN<br />
POLICY FOR SLIDE REVIEW<br />
• Automatic Review (director requested)<br />
– Sterile fluid or tissue<br />
• Microorganism reported<br />
• 3-4 + PMN’s with no bacteria seen<br />
– Non-sterile source<br />
• Report is diagnostic<br />
• Requested Review (technologist requested)<br />
– Unsure of finding<br />
• Physician requested review<br />
– Interpretation
BACTERIAL MORPHOLOGIES<br />
LEVEL I<br />
MINIMUM COMPETENCY<br />
MORPHOLOGY REPORTED ORGANISM IMPLIED<br />
• Gram-positive cocci clusters Staphylococcus<br />
• Gram-positive coccci pairs/chains Streptococcus<br />
• Gram-positive cocci Staphylococus/Streptococcus<br />
• Gram-positive rod Any Gram-positive rod<br />
• Gram-negative diplococci Neisseria/Moraxella<br />
• Gram-negative coccobacilli Haemophilus/Bacteroides<br />
• Gram-negative rod Any Gram-negative rod<br />
• Yeast cells Yeast, usually Candida<br />
• Yeast cells with pseudohyphae Candida, not C. glabrata<br />
• O<strong>the</strong>r findings-leave <strong>for</strong> review<br />
• Cell morphologies<br />
– PMNs<br />
– Squamous epi<strong>the</strong>lial cells<br />
– Sputum screens
BACTERIAL MORPHOLOGIES<br />
LEVEL II<br />
Senior Technologists/Supervisors<br />
MORPHOLOGY REPORTED ORGANISM IMPLIED<br />
• Level I plus…<br />
• Gram-positive diplococci lancet-shaped S. pneumoniae<br />
• Gram-positive rod diph<strong>the</strong>roid Corynebacterium, etc.<br />
• Gram-positive rod boxcar Bacillus/Clostridium<br />
• Gram-positive rod endospores Bacillus/Clostridium<br />
• Gram-positive rod filamentous/branching Nocardia/Actinomyces<br />
• Hyphae septate Aspergillus, etc. type<br />
• Hyphae nonseptate Rhizopus, etc. type
BACTERIAL MORPHOLOGIES<br />
Level II<br />
Senior Technologists/Supervisors<br />
MORPHOLOGY REPORTED ORGANISM IMPLIED<br />
Continued<br />
• Gram-negative rod thick Enterobacteriaceae-type<br />
• Gram-negative rod thin Nonfermenter-type<br />
• Gram-negative rod pleomorphic Bacteroides-type<br />
• Gram-negative diplobacilli Acinetobacter-type<br />
• Gram-negative rod fusi<strong>for</strong>m Fusobacterium-<br />
/Capnocytophagia-type<br />
• Gram-negative rod curved Campylobacter/Vibrio<br />
• Gram-negative cocci tiny Brucella/Francisella
Interpretations<br />
Level III<br />
Laboratory Directors/Medical Microbiologists<br />
• Level I and Level II plus<br />
• Additional cells<br />
• Indicators of <strong>pathology</strong><br />
• Disease pattern recognition (Cases)<br />
– Vesico-colic fistula
Interpretations<br />
Level III<br />
Laboratory Directors/Medical Microbiologists<br />
• Disease pattern recognition<br />
– Respiratory tract<br />
• Pneumonia/bronchitis<br />
• Aspiration pneumonia<br />
• Chronic lung disease/COPD<br />
– Urinary tract<br />
• UTI<br />
• Vesico-colic fistula<br />
– Meningitis
Interpretations<br />
Level III<br />
Laboratory Directors/Medical Microbiologists<br />
• Skin-Soft Tissue-Closed Space Abscess<br />
– Staphylococcal<br />
– Mixed aerobic/anaerobic<br />
– Streptococcus milleri/anginosis<br />
– Nocardia<br />
• Toxemia<br />
– Streptococcal necortizing fasciitis<br />
– Clostridium gas gangrene<br />
• Miscellaneous<br />
– BV (bacterial vaginosis)<br />
– Lemierre’s disease (jugular vein thrombosis)<br />
– Gonococcal urethritis (male)<br />
– Crystalline joint disease
How To Make Gram Stain Reporting<br />
Relevant in <strong>the</strong> Future<br />
• Standardize smear preparation<br />
• Standardize staining procedures<br />
• Standardize reporting<br />
• Maintain levels of competency<br />
– Level I<br />
– Level II<br />
– Medical Microbiologist Interpretations<br />
• Standardize Gram stain review
Radiology Model
How To Make Gram Stain<br />
Reporting Relevant in <strong>the</strong> Future<br />
• Technologist <strong>gram</strong> stain report with digital<br />
images inserted in <strong>the</strong> report and an<br />
accompanying interpretation by <strong>the</strong> medical<br />
microbiologist<br />
• MICROBIOLOGY MODEL
Comment: Gram stain<br />
reviewed by Dr. Thomson.<br />
Branching septate hyphae<br />
also present among PMNs.<br />
Morphology suggests<br />
Aspergillus or<br />
morphologically similar<br />
mold. See attached image.
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