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258 Cards in this Set

  • Front
  • Back
Name the test and what it is for
Name the test and what it is for
Catalase test
Differentiate:
- Staphylococcus (+) from Streptococcus (-)
- Among small non-branching, non-spore forming aerobic gram positive bacilli:
( + ) Listeria spp. Corynebacterium spp.
( - ) Erysipelothrix rhusiopathiae (H2S+), Arcanobacterium haemolyticum
Name the test and what it is for
Name the test and what it is for
Coagulase tube test: detects free coagulase producing organisms
Coagulase-positive staphylococci:
Staphylococcus aureus subsp. anaerobius
S. a. aureus
S. a. delphini
S. hyicus
S. intermedius (dog bite)
S. lutrae
Staphylococcus schleiferi subsp. coagulans

Coagulase-negative staphylococci:
S. saprophyticus
S.cohnii subsp. cohnii
S. cohnii subsp. urealyticum
S. captitus subsp. captitus
S. warneri
S.hominis
S.epidermidis
S. caprae
S. lugdunensis (+ with bound/slide coagulase test and PYR+)
Coagulase test = Rabbit plasma + organism incubated at 35*C and checked at 4 hr and 24 hr
Name the test and what it is for
Name the test and what it is for
Coagulase slide test: detects bound (clumping factor) coagulase producing organisms

S. aureus group and S. lugdunensis ( - coagulase tube test)
Name the test and what it is for
Name the test and what it is for
Coagulase latex agglutination test: detects bound (clumping factor) coagulase producing organisms

S. aureus group and S. lugdunensis ( - coagulase tube test)
Name the test
Name the test
Kirby-Bauer disk diffusion antibiotic sensitivity testing showing nosocomial MRSA
Name the test
Name the test
Kirby-Bauer disk diffusion antibiotic sensitivity testing showing community acquired MRSA with positive D-test
Novobiocin disk/gram stain, name the organism on the right side
Novobiocin disk/gram stain, name the organism on the right side
Staphylococcus saprophyticus

Coagulase - Staph. involved in approximately 10-20% of UTI (young females)
Name the probable organism
Name the probable organism
Clostridium perfringens showing double zone of Beta hemolysis on SBA
Lecithin Lactose Agar
Lecithin Lactose Agar
Clostridium perfringens precipitates lecithin around colonies (opaque halo)
thioglycolate broth
thioglycolate broth
Clostridium perfringens in thioglycolate broth, showing gas production
Name organism
Name organism
Pseudomonas aeruginosa on BAP showing metallic haze colonies
Mac Conkey agar
Mac Conkey agar
Pseudomonas aeruginosa on MAC
Glucose non-fermenter, oxidase positive
KIA/TSI tube, organism?
KIA/TSI tube, organism?
K/K:
non-glucose, non-lactose, non-sucrose fermenter
No H2S

Pseudomonas
Type of hemolysis, possible organisms
Type of hemolysis, possible organisms
Beta-hemolysis

Groups
A (pyogenes)
C (S. dysgalactiae Subs. equisimilis)
G (S. equi Subs. zooepidermicus)

B (pyogenes)
β-hemolytic enterococci
Bacitracin test
Bacitracin test
Group A Streptococcus (pyogenes) is susceptible to Bacitracin

Bacitracin resistant Beta-Hemolytics
S. milleri group (F)
S. dysgalactiae Subs. equisimilis (C)
S. equi Subs. zooepidermicus (G)
β-hemolytic enterococci
PYR test
PYR test
Positive in Streptococcus pyogenes (GAS)

AND Beta-hemolytic Enterococci
Lancefield testing caveat
Lancefield testing caveat
Does not distinguish between large-colonyforming,
pyogenic streptococci of groups A, C and G and
small-colony-forming group A, C and G strains of the
anginosus or “S. milleri” group
This bacterium grew in Regan-Lowe medium forming round, domed, mercury-silver, colored, shiny colonies
This bacterium grew in Regan-Lowe medium forming round, domed, mercury-silver, colored, shiny colonies
Bordetella pertussis

Culture sensitivity:

• If ≥14 days from onset of cough, sensitivity is
lower, so serology is sent instead of culture

• Caveat: Serology is uninterpretable in immunized
or unimmunized patients <11 years of age
– These patients are cultured regardless of duration of
symptoms
Name organism
Name organism
Corynebacterium diphtheriae

Non-motile
Catalase +
Name organism and medium
Name organism and medium
Tellurite-containing medium, black colonies of Corynebacterium diphtheriae
Optochin Susceptibility Test, name organism
Optochin Susceptibility Test, name organism
Streptococcus pneumoniae

Optichin sensitive, > 14 mm. inhibition
BHI agar, what is preferable for this organisms? 
Name organisms:
Green arrow 
Red arrow
Blue arrow
BHI agar, what is preferable for this organisms?
Name organisms:
Green arrow
Red arrow
Blue arrow
Preferable medium for Haemophilus spp.:
Chocolate agar or Horse blood agar with free X (hemin) and V (NAD)
Red (X and V)
H. influenzae
H. haemolyticus
Green (V only) - ("The P's like the V")
H. parainfluenzae
H. paraheamolyticus
Blue (X only) - ("X-Rated")
H. ducreyi
S. aureus streak
S. aureus streak
Haemophilus spp. satellitism

S. aureus produces V and if Beta-hemolytic releases X from SBA
Gram + methylene blue: name organism
Gram + methylene blue: name organism
Corynebacterium diphteriae

Metachromatic granules with methylene blue
BYCE medium, name organism
BYCE medium, name organism
Legionella pneumophila 

Buffered Charcoal Yeast Extract agar

Legionella won't stain with gram on direct specimens, it will from subculture specimens
Legionella pneumophila

Buffered Charcoal Yeast Extract agar

Legionella won't stain with gram on direct specimens, it will from subculture specimens
Facultative anaerobes, Acid Fast negative, organism group?
Facultative anaerobes, Acid Fast negative, organism group?
Actinomyces spp.
Molar tooth colonies
Molar tooth colonies
Actinomyces israelii
Acid fast stain
Acid fast stain
Nocardia spp
Chalky-white colonies when young then yellow/orange colonies
Chalky-white colonies when young then yellow/orange colonies
Nocardia asteroides
Medusa-head colonies
Medusa-head colonies
Bacillus anthracis
Name organism
Name organism
Bacillus anthracis
Name organism
Name organism
Bacillus anthracis
Optichin disks
Optichin disks
Resistant

PYR positive, Bile esculin positive: Enterococcus spp.

PYR negative:

Bile esculin positive: S. bovis (D)
Bile esculin negative: Viridans
Ampicillin Resistant  
Vanco Sensitive
Enterococcus spp
Ampicillin Resistant
Vanco Sensitive
Enterococcus faecium non-VRE
Ampicillin Vancomycin Resistant
Enterococcus spp
Ampicillin Vancomycin Resistant
Enterococcus faecium VRE
Ampicillin, Vancomycin susceptible
Enterococcus spp
Ampicillin, Vancomycin susceptible
Enterococcus faecalis
Quad plate
Enterococcus spp
Quad plate
Test for synergy of aminoglycosides with vancomycin for Enterococci causing bacterial endocarditis
Urease test, gram and tissue, name organism
Urease test, gram and tissue, name organism
Brucella melitensis

Castaneda biphasic blood culture held for 21 days historically used for culture
Common-antigen test (glutamate
dehydrogenase or GDH test)
Used as a screening test for C. diff. to decide which
specimens to evaluate using another assay (e.g.,
cytotoxicity assay or toxin EIA)
Glucose fermenting
Nitrate to nitrite
Oxidase negative

Possible organisms with this colony type in Mac Conkey
Glucose fermenting
Nitrate to nitrite
Oxidase negative

Possible organisms with this colony type in Mac Conkey
Lactose fermenting

E. coli (indole+)
Enterobacter spp. (VP test +, catalase+, citrate+)
Klebsiella spp. (VP test +, non-motile, mucoid colonies)
Hektoen enteric agar
Hektoen enteric agar
E. coli
Hektoen enteric agar
Hektoen enteric agar
Salmonella spp.

H2S production
KIA-TSI
KIA-TSI
E. coli
Enterobacter
Klebsiella
Acid Slant/Acid Butt (A/A)

Shigella
Vibrio
Alkaline Slant/Acid Butt (K/A)


Salmonella
Citrobacter
Proteus
Alkaline Slant/Acid Butt (K/A) + H2S

Pseudomonas
Alkaline Slant/Alkaline Butt (K/K)
CIN agar
CIN agar
Yersinia enterocolitica

•Septicemia in iron overload syndromes
•Mesenteric adenitis – RLQ pain mimics appendicitis
•Grows well at 4*C (like Listeria)
•CIN agar (Cefsulodin-irgasan-novobiocin)
Safety pin morphology
Safety pin morphology
Yersinia pestis
TBCS agar
TBCS agar
Vibrio cholerae

Oxidase positive/glucose fermenter
KIA: K/A

TCBS (Sucrose)
Yellow: V. cholerae
Green: V. vulnificus, V. parahaemolyticus
Gram, identify organism group
Gram, identify organism group
Vibrio spp
Special BAP medium, at 42°C and @ 5% O2, 10% CO2, 85% nitrogen 
• Catalase positive
• Oxidase positive
Special BAP medium, at 42°C and @ 5% O2, 10% CO2, 85% nitrogen
• Catalase positive
• Oxidase positive
Campylobacter spp

• Hippurate hydrolysis test
– If positive, identifies isolate as C. jejuni
– Of Campy species, only jejuni is positive
Name organism
Motile
Name organism
Motile
E. coli
MUG test positive (β-glucuronidase activity)
MUG test positive (β-glucuronidase activity)
E. coli
Name organism
Non-motile
VP+
Name organism
Non-motile
VP+
Klebsiella spp

Indole:

+ K. pneumoniae

- K. oxytoca
Name organism
Name organism
Proteus spp

Indole:

+ P. vulgaris

- P. mirabilis
Name organism
Coagulase -
Novobiocin resistant
Name organism
Coagulase -
Novobiocin resistant
Staphylococcus saprophyticus
Name organism
Thayer Martin
Glucose fermenting
Name organism
Thayer Martin
Glucose fermenting
Neisseria gonorrheae

Molecular amplification methods
– Permit concurrent detection of CT in single specimen
– Allow use of urine as a specimen (non-invasive)
– Do not require viable organisms (transport not an issue)
– Highly sensitive
– Rapid
• Disadvantages:
– GC DNA may be present up to 3 weeks after successful
treatment, so NAATs should not be used as test of cure
– Isolates not available for susceptibility testing if treatment
difficulties arise
– Results inadmissible evidence in medicolegal cases
Blue
Pink
Yellow
Green
Magenta
Blue
Pink
Yellow
Green
Magenta
Blue: GBS
Yellow: Listeria monocytogenes
Pink: Pneumococcus
Green: Neisseria meningitidis
Magenta: H. influenzae
Name organism

Thayer-Martin
Ferments maltose
Name organism

Thayer-Martin
Ferments maltose
Neisseria meningitidis
Lazy-Beta hemolysis
Lazy-Beta hemolysis
Streptococcus agalactiae
Name organism
Name organism
Streptococcus agalactiae
Name organism
Name organism
Listeria spp.
Name organism
Name organism
Listeria monocytogenes
Hyperdiploidy (> 52 chromosomes)

t(12:21)/TEL-AML1 - cryptic, use FISH
Favorable cytogenetics for ALL
t(9;22) (q34;q11) ABL/BCR (p190)

t(4;11)(q21;23) MLL-AF4

11q23/MLL rearrangments

t(1;19)(q23;p13) PBX/E2A

Hypoploidy < 40 chromosomes

Near tetraploid
Unfavorable cytogenetics for ALL
t(4;11)(q21;q23) in ALL
Expression of CD15 and loss of CD10 (5% of B-ALLs)
Inv(16) or t(16;16)(p13;q22)

t(8;21)(q22;q22) AML1/ETO
Favorable cytogenetics for AML

Inv(16) or t(16;16)(p13;q22) Core binding factor β and smooth muscle myosin heavy chain

- 10-12% of AML (often younger pts.)
- Myeloid sarcoma may be present at diagnosis
- Myelomonocytic morphology (M4 Eo) with abnormal eosinophils (basophilic granules)
- Auer rods in some cases
- AT LEAST 3% of blasts positive for MPO
- Blasts often at the 20% threshold
- May coexpress CD2


t(8;21)(q22;q22) AML1/ETO (core binding factor)

- May present as granulocytic sarcoma
- Large blasts with abundant cytoplasm
- Pseudo-Chediak-Higashi granules, Auer rods
- “AML with maturation” (may have mono diff)
- Aberrant coexpression of CD19, maybe CD56
t(15;17)(q22;q21)

+8

t(9;11) (children)

t(6;9)
Intermediate cytogenetics for AML

AML with t(15;17)(q22;q12)

- Acute promyelocytic leukemia (typical and microgranular forms)
- Associated with DIC; microgranular – high WBC count; typical – low count
- Nuclei of blasts often reniform or bilobed
- Numerous Auer rods
- MPO is VERY strong in both forms (why?)
- CD34 and HLA-DR often negative; CD33 bright, may have CD2 coexpression
- Response to ATRA and induction chemo good except in t(11;17)(q23;q21) and t(5;17)
- 7

- 5

del 7q

11q23 MLL rearrangements

inv(3q)

Complex abnormalities
Bad cytogenetics for AML
MPO in myeloid blasts
MPO in myeloid blasts
PAS in erythroid blasts
"Apple core" nuclei of APML
APML in BM

• t(15;17) – RARα and PML
– All-trans retinoic acid (ATRA) responsive
– t(11;17) and t(5;17) – less responsive
PAS in ALL
Normal karyotype

-Y

isolated 5q-
Good cytogenetics for MDS
20q-

+8
Intermediate cytogenetics for MDS
Complex karyotype

5q- associated with any other abnormality

17p abnormality

loss of 7
Bad cytogenetics for MDS
Non-specific esterase (NSE)

ANB (alpha napthyl butyrate)
Diffuse cytoplasmic positivity in monoblasts
ANA (alpha napthyl acetate)
Similar reactivity in monoblasts, but inhibited by sodium fluoride (NaF) (vs. megs, erythroid)
Hematogones on flow cytometry
Extra Philadelphia chromosome

trisomy 8

isochromosome 17q 

trisomy 19
Extra Philadelphia chromosome

trisomy 8

isochromosome 17q

trisomy 19
CML Clonal progression
Rouleaux with background staining

high-protein states, reactive or clonal
Agglutination (100 oil)

cold agglutinin disease
Dual population (40 dry).

This could be seen in partially treated/transfused iron deficiency, sideroblastic anemias, and combined B12/iron deficiency. Transfusion
Spherocytes (100 oil).

Spherocytes can be seen in
hereditary spherocytosis, autoimmune hemolytic anemia, and acute hemolytic transfusion reaction. Microspherocytes, which are even smaller spherocytes, can be seen in Clostridium perfringens infection and in thermal injury (eg, burns).
Oxidative process (100 oil).

Blister cells are smaller red blood cells that lack a central pallor. The blister appears as a vacuole at the red blood cell surface. A thin rim of cytoplasm appears to enclose this vacuole.
Bite cells are smaller red blood cells that lack a central
pallor and appear to have an oval bite taken out of the red blood cell. Some cells have more than 1 bite per cell.
Bite blister, and irregularly contracted red blood cells can be seen in oxidative hemolysis (eg, G6PD deficiency) and unstable hemoglobinopathies.
Fragments (100 oil).smaller red blood cells that lack central pallor.
They are jagged in shape and appear as a piece of red blood cells.
Note how an occasional spherocyte is seen (indicated by the dotted arrows) and a rare, irregularly contracted RBC (indicated by the
thick arrow) is seen. In a microangiopathic (fragmenting) process, occasional spherocytes and irregularly contracted cells are seen; however, this does not represent 2 or 3 separate processes because
the fragments are in the majority.
Echinocytes (100 oil). Also called burr cells

Renal disease, hypophosphatemia, and blood film artifact.
Acanthocytes (100 oil). Also called spur cells

McCleod syndrome
Movement disorders
Microcytic disorders such as iron deficiency and hemoglobinopathies and in normocytic/macrocytic disorders such as liver disease and hyposplenic states.
Eliptocytes (100 oil).

Hereditary eliptocytosis, hemoglobinopathies,
and iron deficiency.
Hyposplenic changes (100 oil).
The solid arrow is demonstrating a Howell–Jolly body, which is a single, round, smooth, dark blue inclusion body seen in this red blood cell. It represents DNA. The dotted arrow indicates Paphenheimer bodies,
which are multiple, jagged and irregular, light blue inclusion
bodies seen in this red blood cell. It represents iron deposition.
Both these inclusion bodies can be seen in hyposplenic states.
Basophilic stippling (100 oil).

Basophilic stippling (RNA) seen in thalassemic states, hemolytic processes, and dysplasia. More coarse basophilic stippling has been described in lead poisoning.
Falciparum malaria (100 oil).
Pelgerized neutrophil (100 oil). The neutrophil on
the left (indicated by the solid arrow) is hypolobulated and has a mononuclear form. This is considered pelgerized. The neutrophil on the right (indicated by the dotted arrow) is normal.
It can be seen in myelodysplastic disorders or congential disorders
Toxic changes (100 oil). The neutrophils on this
film demonstrate increased dark red––purple granulation, consistent with toxic granulation.
Megaloblastic changes (100 oil). A hypersegmented
neutrophil with greater than 6 nuclear segments is seen
Various platelet sizes and morphologies (100 oil).
The solid arrow indicates a giant hypogranular platelet. The dotted arrow indicates a giant granular platelet. Giant platelets are larger than the size of a normal red blood cell.
Circulating plasma cells (100 oil). Note the rouleaux formation in the red blood cells.
Cryoglobulinemia (100 oil). Cloud-like pale purple
cryoglobulin deposits are seen in between and overlaying the red blood cells. When the cryoglobulins overlay the red blood cells, they can give the false appearance of irregularly contracted and bite cells, especially if the cryoglobulins are small and not darkly stained.
May-Hegglin anomaly, showing Döhle-like inclusions (×1000).
The Alder-Reilly anomaly may be found in healthy individuals or in those with mucopolysaccharidoses, in which granules are metachromatic (×1000).
Chédiak-Higashi neutrophils and lymphocytes with large granules
Inherited Pelger-Huët anomaly (×1000).
del(13q14.3)
Good cytogenetics for CLL/SLL
trisomy 12

del(11q22-23)

del(17q)(TP53)
Bad cytogenetics for CLL/SLL
Diffuse infiltrate of the BM

Increased proportion of prolymphocytes (between 10% and 55%)

CD38 (> 30% of cells) and ZAP-70

Unmutated IgVH gene
Bad prognostic features SLL/CLL
MCL

t(11;14)(14q32)(11q13) IGH-CCND1
Blastoid variant/pleomorphic variant  

+ 12

+ 3q

-9q

Complex karyotype

p53 mutations
Blastoid variant/pleomorphic variant

+ 12

+ 3q

-9q

Complex karyotype

p53 mutations
Bad prognostic features for MCL
MCL in BM: non-paratrabecular infiltrates with histiocytes
FL t(14;18)(p32)(q21) IGJH-BCL2

Grading:

Centroblasts:

I: 0-15 per HPF
II: 5-15 per HPF
IIIa: >15 per HPF
IIIb: Sheets of centroblasts
FL in PBS
Paratrabecular deposits of FL in BM

Also seen in T-cell rich B-cell lymphoma
- t(11;18) – stomach, lung

– t(1;14) – ocular, parotid, cutaneous

– t(3;14) – ocular, thyroid, cutaneous

– t(1;14) – lung, small bowel

+3 +18 All MZL
SLVL
•Moderate quantity of cytoplasm
•Polar villi
•Nucleoli

CD19+, CD20+, sIg+, CD11c+
but unlike HCL:
CD103 neg (usually), annexin A1 neg
HCL
• Cytopenia: neutropenia, monocytopenia
• Immunophenotype
– CD19+, CD20+, sIg+,
– CD11c+ (very bright), CD25+, CD103+, Annexin A1+
– Bcl‐1+
• TRAP+
BM in HCL:

- Dry tap (increased fibrosis)
- Stripped nuclei
- Blood lake formation
PEL

- HHV-8+
– Like KS and Multicentric Castleman’s
• HIV +
• Effusion contains large cells with
– Immunoblastic, plasmablastic, anaplastic features
C t l i li ti
HHV8
– Cytoplasmic vacuolization
• Neg for B-cell, T-cell, myeloid antigens
• Pos for CD45, CD30, CD38, CD138, EMA
• Clonal Ig rearrangement +
BL

Immunophenotype
– CD19+, CD20+, sIg+, CD10+, BCL6+,
– CD34 neg, TdT neg, BCL2 neg
t(8;14)

t(2;8)

t(8;22)

– Always involving C-MYC (8)
MM

Three prognostic groups

– Shortest survival – t(4;14), t(14;16), or del(17p)

– Intermediate survival – 13q14 deletions alone

– Longest survival – no anomalies or only t(11;14)
Essential Thrombocythemia (ET)

• Bimodal, female > male
• Most stable MPD
• Minimal splenomegaly
• Marrow
– Hypercellular
– Large, hyperlobated megakaryocytes
– Clustered, paratrabecular megakaryocytes
• Cytogenetics
– Abnormal in <10%
PF

• Cellular (prefibrotic) phase
– Marrow hypercellular with increased
megs
– Abnormal megs – appearance and
location
• Fibrotic phase
– Leukoerythroblastic pattern
– Intrasinusoidal hematopoiesis
• Cytogenetics
– 50% abnormal: del(20q), del(13q),
+8, +9
MPO+SBB:

Granulocytic maturation
– M1, M2, M3, M4
N t MPOd d
MPO SBB
• Note: MPO degrades
quickly in wet specimens

NSE+NSE NaF

Monocytic maturation
– M4, M5
• Sodium fluoride (NaF)
inhibition specific for
monocytic cells
APML – microgranular variant
• Autosomal dominant
• Giant platelets, thrombocytopenia, Döhle-like inclusions
• Related to: Fechtner, Sebastian, and Epstein syndromes
• Chromosome 22q12-13 (MYH9 gene – myosin)

May-Hegglin anomaly
• Most cases seen in children,
median age 2 years
• History of developmental delay
or ophthalmic conditions
• Most common:
– Neuronal ceroid lipofuscinosis (Batten
disease)
– Acid maltase deficiency (Pompe
disease)
– Tay Sachs

Vacuolated lymphs
Gauchers syndrome

Glucocerebroside deficiency
E. vermicularis eggs
Trichuris ovum
Fertilized Ascaris egg (L)

Unfertilized Ascaris egg (R)
Hookworm egg
Hookworm rhabditiform larva
Strongyloides rhabditiform larva
Capillaria philippinensis ovum
• All stages seen (early ring forms to gametocytes)
• RBCs enlarged (trophozoites and later stages)
• As RBC enlarges, membrane remains smooth
• Schuffner’s stippling in intermediate forms
• Schizonts: >12 merozoites
• Gametocyte fills most or all of host cell
• Cycle: 48 hours

P. vivax
• All stages seen (early ring forms to gametocytes)
• RBCs enlarged (trophozoites and later stages)
• As RBC enlarges, membrane shows projections
• Schuffner’s stippling in intermediate forms
• Schizonts: ≤12 merozoites
• Gametocyte does not fill entire host cell
• Cycle: 48 hours

P. ovale
P. falciparum, thick smear
P. falciparum, thin smear
P. falciparum, gametocyte

• Heavy parasitemia
• Only early ring forms and gametocytes are seen
• Few if any schizonts or trophozoites
• Rings: double chromatin dots common (“headphones”)
• Marginal rings common (applique cells)
• RBCs not enlarged
• No Schuffner’s stippling
• Banana-shaped gametocytes
• Cycle: 36-48 hours
• Mostly mature forms seen (trophs, schizonts and
gametocytes)
• Few ring forms
• RBCs not enlarged
• No Schuffner’s stippling
• Trophozoites can appear as “band forms”
• Schizonts: 6−12 merozoites
• Cycle: 72 hours

P. malariae
Babesia, tetrad
The banana-shaped
gametocyte is diagnostic
if seen.
• Early rings, no trophs
– Applique’ forms
– Dual infected cells
– Dual chromatin dots

P. falciparum
• Infected large,
young RBCs
– And also causes
enlargement
– BIG RBCs.
• Amoeboid
trophozoites
• Schuffner’s granules
• 12-20 merozoites/
schizont

P. vivax
• Infects old, small RBCs.
• Heavy, blocky trophs
• ‘Band forms
• 8-12 merozoites/ schizont
• Heavy malarial pigment
• ‘Rosette’ forms

P. malariae
W. bancrofti

Sheathed
Vector: Mosquito
Nocturnal
Loa loa

Sheathed
Vector: Mango fly (Chrysops)
Diurnal
O. volvulus

Unsheathed, from skin,
not blood
Vector: Black fly (Similium)
H. nana egg, iodine wet prep
Hymenolepis diminuta (rat tapeworm) eggs

• Size: 70-85 μm X 60-80 μm (larger than H. nana)
• Smooth shell, thicker than H. nana egg shell
• Shell is often yellow to brown in color
• Onchosphere (embryo) inside shell
• No polar thickenings on embryo membrane
• No filaments
D. latum egg, iodine wet prep
Sparganosis

Spirometra spp.
S. mansoni egg, saline wet prep
S. japonicum egg
S. haematobium egg with hatching miracidium
• Hermaphrodite worms
• Morphologically similar
ova
• 130-159 um long
• Small operculum, may
pop open when cover
slip pressed

Fasciola & Fasciolopsis
Clonorchis/Opisthorchis egg, iodine wet prep
adult flukes
overall resemble
coffee beans, may
live 10-20 years
• Eggs found in
feces or sputum
– Prominent
operculum
– 68-118 um long

Paragonimus spp.
• Does not form cysts
• Size: 9-12 μm
• Trophozoite has 2 nuclei
• No observable flagella, but classified as a flagellate
• Moves by means of pseudopodia when seen in feces
• Fairly strong association between Enterobius vermicularis
and D. fragilis infections has been noted—suggesting that
D. fragilis may sometimes be transmitted via pinworm
eggs

Dientamoeba fragilis
• Detection of oocysts in stool
• Modified acid fast stain of concentrated
stool specimen
• Football shaped (oval with tapered ends)
• Size: 20-33 μm long X 10-19 μm wide
• Single sporoblast inside
• Color: Red (MAF stain)

Isospora belli
Cyclospora and Cryptosporidium oocysts, MAF stain

Detection of oocysts in stool
• Modified acid fast stain of concentrated
stool specimen
• Shape: Spherical
• Size: 8-10 μm (twice the size of
Cryptosporidium oocysts)
• Color: Red (MAF stain)

Cyclospora cayetanensis
Microsporidial spores in stool, modified trichrome stain

• Histology: PAS, GMS, acid-fast stains highlight
organisms in tissue biopsy
• Modified trichrome-stained fecal smears can
reveal spores
• Characteristic orange-red color on modified
trichrome stain
• Size: 1-2 μm
• Shape: round
• Red “band” or dot is often present

Microsporidia spp
Eggs are 60-75 m in
length and 40-50 m
wide
– Operculum, sometimes
difficult to visualize
– Small knob on the
abopercular end, may
or may not be evident;
sometimes only a
roughening or
thickening of the egg
wall

Diphyllobothrium latum
• T. solium: 7-13 uterine branches
• T. saginata: 15-30 branches

• Beef tapeworm -- T. saginata
– sub-Saharan Africa, the Balkans and Middle
East, Latin America, and Russia
– 77 million infected
• Pork tapeworm -- T. solium
– Latin America (especially Mexico), Africa,
southeast Asia, and eastern Europe
– 10 million infected
HSV infected cell monolayer Rounded cells on edge of monolayer Rapid cell killing
VZV
infected monolayer Foci of sandpaper CPE with rounded cells
CMV infected monolayer Focal grape like cluster of rounded cells
EBV Serodiagnosis
Heterophile antibodies (HA) react with antigens phylogenetically unrelated to the antigenic determinants against which they were raised
HA secondary to EBV are detected by their ability to react with horse or cattle rbc’s. (Monospot test)
Rise in the first 2 - 3 weeks of EBV infection, then rapidly fall at @ 4 weeks
Cannot be used in children < 4 years of age
Adenovirus CPE – rounded cells Connected by strands
CPE of Enterovirus Teardrop and kite like cells
Classic CPE = Syncytium formation Respiratory syncytial virus CPE
Ziehl-Neelsen smear from broth culture, M. tuberculosis

Cording factor
MTB: Susceptibility Testing
• Rapid method
– Broth culture using single “critical concentration” for
each drug
– Streptomycin, INH, rifampin, ethambutol, PZA
• Standard method
– Agar proportion
– Also uses critical concentrations, but other
concentrations sometimes added
– Expanded panel of drugs can be tested
MDR and XDR TB
• MDR TB: TB isolate that is
resistant to both isoniazid and
rifampin
• XDR TB: MDR + resistance to
fluoroquinolone and 1 of the 3
injectable drugs (amikacin,
kanamycin, capreomycin)
, shielded , exposed (R)
M. kansasii, shielded (L)
M. kansasii, exposed (R)
exposed
• Slow growth
• Temperature preference = 37°C
• Thin, long, branching, acid-fast rods on smear from liquid
culture
• Usually nonchromogenic; some isolates can be pigmented
• Identification by DNA probe from culture
– All 3 MAC species are recognized by the commercial DNA probe
for MAC (Accuprobe by GenProbe, San Diego); does not
differentiate between species
– Specific probes for M. avium and M. intracellulare exist; MAC-X
is negative by both

M. avium complex
exposed
• Found in hot water systems—optimum growth
temperature is 42°C
• May take 6 weeks or longer to grow because 37°C
incubation is not optimal
• Causes chronic pulmonary disease in adults with
underlying disease (e.g. COPD or bronchiectasis)
• Extrapulmonary infection seen only in
immunocompromised

• Slow growth
• Optimum growth at 42°C
• Long, thin, branching, acid-fast rods on
smear from liquid culture (“atypical
morphology”)
• Scotochromogenic
• Identified biochemically

M. xenopi
, shielded , exposed (R)
• Causes cutaneous infection
• Associated with exposure to freshwater fish
tanks or saltwater following trauma
• “Fish tank granuloma”—single nodular
lesion confined to one extremity
• Appears 2-3 weeks after inoculation
• In US, most common in southern coastal
states

• Classified as a slow grower, but some strains
manifest rapid growth
• Primary isolation requires incubation at 30°C
• Thin, long, branching, acid-fast rods on smear
from liquid culture (“atypical” morphology)
• Photochromogenic
• Identified biochemically

M. marinum
• Most commonly recovered non-pathogenic
NTM
• Non-pathogenic even in
immunocompromised patients
• Widely distributed in soil and water
• Frequently contaminates respiratory
specimens sent for mycobacterial culture

M. gordonae
Rapid Growers

• All are 3-day arylsulfatase positive
• All grow on MacConkey agar lacking
crystal violet
• Differentiated using 3 biochemical tests:
iron uptake, salt tolerance, and nitrate
reduction
M. fortuitum group
• Positive iron uptake
• Tolerant to 5% NaCl (heavy growth)
• Positive nitrate reductase
• Resistant to all standard anti-TB drugs
• Many drug options, including amikacin, cefoxitin,
quinolones (ciprofloxacin, gatifloxacin,
moxifloxacin), clarithromycin, doxycycline,
sulfonamides, imipenem)
• Drug combinations are recommended

M. chelonae: Features
• Negative iron uptake
• Not tolerant to 5% NaCl (minimal growth)
• Negative nitrate reductase
• Resistant to all standard anti-TB drugs
• Fewer drug options than M. fortuitum
– Susceptible to amikacin, imipenem, tobramycin,
clarithromycin
– Resistant to fluoroquinolones, cefoxitin
• Clarithromycin is the drug of choice for localized
infections

M. abscessus: Features
• Negative iron uptake
• Tolerant to 5% NaCl (heavy growth)
• Negative nitrate reductase
• Resistant to all standard anti-TB drugs
• Fewer drug options than M. fortuitum
– Susceptible to amikacin, cefoxitin, imipenem,
clarithromycin
– Resistant to fluoroquinolones
• Clarithromycin is the drug of choice for localized
infections, although resistant strains are emerging
Plate morphology
– Cream/white colored, smooth, large colonies
– Colonies on BAP show mycelial projections into the agar, called “feet” or
“star-like”

Candida albicans
Microscopic morphology
– In primary smears, relatively large (3-6 μm) budding yeast with
pseudohyphae (and sometimes true hyphae)
– When grown on morphology medium:
• Pseudohyphae with clusters of blastoconidia at the septations
• Single terminal chlamydospores (large, thick-walled)
• Some true hyphae may be seen as well
• Positive by germ-tube test within three hours
• Smooth green colonies on Candida Chromagar plate
• Detection of β-D-galactoaminidase activity

Candida albicans
• Plate morphology
– Small colonies, smooth, glistening
– White to cream colored

Candida glabrata
• Microscopic morphology
– In primary smears, small ( 2-5 μm) budding yeast
without pseudohyphae or true hyphae
– When grown on morphology medium:
• Budding blastospores
• No other structures
• Positive by rapid assimilation of trehalose test
(RAT assay)

Candida glabrata
Antifungal Susceptibility
Candida spp
• Candida albicans is generally sensitive to azoles and other
antifungals
• 10% of Candida glabrata isolates are azole resistant
• Another 20-30% have reduced azole susceptibility
• C. krusei is intrinsically resistant to fluconazole
• C. lusitaniae is considered resistant to amphotericin
(despite low MICs in many cases)
• C. parapsilosis, C. krusei, C. guilliermondii and C.
lusitaniae sometimes exhibit relatively high caspofungin
MICs but most are probably susceptible
Antigen Detection: Specificity

Cryptococcus neoformans
• Very few false-positive results, when
performed properly
• Cause of false positives:
– Trichosporon beigelii infection (cross-reactive
polysaccharide is produced)
– Contamination with agar and syneresis fluid on
agar
– Platinum wire loops
Antigen Detection: Sensitivity

Cryptococcus neoformans
• Varies by population, stage or duration of
infection, and assay methodology
• In general, highly sensitive (~99%)
• At least as sensitive as culture
• Most false-negative results are due to extent of
infection
– Single focal lesions, e.g., pulmonary lesions, may not
produce a great quantity of antigen
– False negatives are less frequent in disseminated or
progressive pulmonary infections, but do occur
C. neoformans on BAP

• Positive for urease activity
• Positive phenol oxidase test
– Detects ability of yeast to produce phenol oxidase on
substrates containing caffeic acid
– Most frequently used medium is birdseed agar
– C. neoformans turns dark brown in 2-5 days; other
cryptococcal species do not
• Identified biochemically using commercial
platforms (e.g. VITEK yeast card)
A. fumigatus
Aspergillus in Tissue (H&E Stain)

Arborescent growth, thin hyphae, 45 degree angle dichotomous branching
Aspergillus in Tissue (H&E Stain)

Arborescent growth, thin hyphae, 45 degree angle dichotomous branching
A. fumigatus

Single row of phialides
A. flavus
A. flavus

Circumferential phialides
A. niger
A. niger

Heavily pigmented
A. terreus
A. terreus

Two rows of phialides
Penicillium spp
Penicillium spp
Penicillium spp
Penicillium spp
Fusarium spp
Fusarium spp

Canoe-shaped/Banana boat

Associated
with Bone marrow transplant
and corneal infections
Fusarium spp

Canoe-shaped/Banana boat

Associated
with Bone marrow transplant
and corneal infections
T. rubrum
T. rubrum

Trichophyton
rubrum
Rare Pencil shaped macroconidia
Many microconidia
T. rubrum

Trichophyton
rubrum
Rare Pencil shaped macroconidia
Many microconidia
Microsporum canis

Rate of growth: moderate; mature within 6-10
days
• Colony morphology: Surface is white and fluffy;
reverse is lemon yellow to yellow-brown
Microscopic morphology: Septate hyphae with
long, spindle-shaped, rough (echinulate)
macroconidia which taper to a knob-like end; few
if any microconidia
• Macroconidia contain >6 cells

Microsporum canis
Microscopic morphology: Septate hyphae with
long, spindle-shaped, rough (echinulate)
macroconidia which taper to a knob-like end; few
if any microconidia
• Macroconidia contain >6 cells

Microsporum canis
Epidermophyton floccosum

• Rate of growth: moderate; mature within 10 days
• Colony morphology: surface yellow to brown to
olive-gray and velvety; reverse is orange to
brownish
• Microscopic morphology: septate hyphae, no
microconidia; macroconidia are smooth, clubshaped
with rounded ends, and contain 2-6 cells;
macroconidia found singly or in characteristic
clusters
Beaver tail spores – no microconidia

Epidermophyton floccosum
Zygomycosis (GMS Stain)

In tissue – 90* angle branching, aseptate, ribbon like
18 hours (L)
48 hours (R)
18 hours (L)
48 hours (R)
Rhizopus spp

Zygomycetes in general
Rhizopus spp
Mucor
Absidia spp
Penicillium marneffei

Red diffusable pigment
Uncommon dimorphic fungus
Skin lesions in tropics
Pneumonia in immune suppressed
Scopulariopsis species
Scopulariopsis species
Paecilomyces species
Paecilomyces species
Trichophyton tonsurans

Epidemic Scalp ring worm
Ballooning microconida
Trichophyton tonsurans

Epidemic Scalp ring worm
Ballooning microconida
Microsporum gypseum - soil
Microsporum gypseum - soil
Trichophyton rubrum

Pencil shaped macroconidia
Many microconidia
Microsporum canis

Dog and cat ringworm
White colony/ yellow reverse
Tuberculate macroconidia –
With very few microconidia
Microsporum canis

Dog and cat ringworm
White colony/ yellow reverse
Tuberculate macroconidia –
With very few microconidia
Malassezia furfur
 Lipophilic yeast – oil required for growth
 Media used for culture must oil or oil overlay
 Small budding yeast 2 – 4 μM with collarette
Malassezia furfur
 Lipophilic yeast – oil required for growth
 Media used for culture must oil or oil overlay
 Small budding yeast 2 – 4 μM with collarette
Exophila spp, mature and early yeast-like 

Black Molds that cause
Mycetoma/Chromomycosis/Phaehypho
Exophila spp, mature and early yeast-like

Black Molds that cause
Mycetoma/Chromomycosis/Phaehypho
young yeast-like colonies

older fuzzy colonies
young yeast-like colonies

older fuzzy colonies
Exophila spp.

Black Molds that cause
Mycetoma/Chromomycosis/Phaehypho
Cladophialophora bantiana

Black Molds that cause
Mycetoma/Chromomycosis/Phaehypho
Cladophialophora bantiana

Black Molds that cause
Mycetoma/Chromomycosis/Phaehypho
Wangiella species
Wangiella species
Phialophora species
Phialophora species
Alternaria spp.
Alternaria spp.
Alternaria spp.
Alternaria spp.
Bipolaris species

Very invasive
Skin, nasal sinuses, bone brain
Bipolaris species

Very invasive
Skin, nasal sinuses, bone brain
Curvularia species
Scedosporium apiospermum/
Pseudallescheria boydii
Exserohilum species

Steroid injections
CSF infections
Exserohilum species

Steroid injections
CSF infections
Pseudallescheria boydii
• The name “P. boydii” refers to the sexual
state of the fungus
• P. boydii is the telemorph of Scedosporium
apiospermum and Graphium eumorphum
(asexual forms)
Scedosporium apiospermum

P. boydii

Graphium
cycloheximide agar (L)
cycloheximide agar (L)
Scedosporium prolificans,
Scedosporium prolificans,
- Grows as a mold at 25°C, grows as a yeast form at 37°C
• Plate morphology:
– Slowly growing, fluffy white colonies initially; buff or brown with age
– Yellow to yellow-brown reverse

• Conversion of the mold to the yeast form at 37°C
• Demonstration of specific precipitins by
exoantigen testing

Histoplasma capsulatum
mold form

yeast form
mold form

yeast form
• Microscopic morphology:
– Large, rounded, single-celled, tuberculate (rough walled)
macroconidia on short conidiophores
– Pyriform microconidia; may be sessile on the sides of hyphae or on
short conidiophores

Histoplasma capsulatum
Tuberculate [projections]
Macroconidia And Microconidia

Histoplasma capsulatum
Sepedonium species

Looks like Histoplasma grows in 5 days/monomorphic
Large rough spores (7 – 17 um),
usually saprophyte
No micro-conida are formed
H. capsulatum var duboisii

Found in Central Africa
Associated with skin and bone lesions
30˚C culture identical to H capsulatum
Yeast cells 8 – 10 um in size 2X the size of regular Histoplasma
Blastomyces Culture at 37*C
Slow growing @ 4 weeks
Culture at 30˚C (L)
Culture at 37*C (R)
Culture at 30˚C (L)
Culture at 37*C (R)
Blastomyces dermatitidis

Culture at 30˚C (L)
Pear shaped conidia like lollipops
Look alike fungus – Chrysosporium species
Do DNA probe to confirm identification

Culture at 37*C (R)
Yeast cell is 8 – 20 um in size
Blastomyces dermatitidis

Culture at 30˚C (L)
Pear shaped conidia like lollipops
Look alike fungus – Chrysosporium species
Do DNA probe to confirm identification

Culture at 37*C (R)
Yeast cell is 8 – 20 um in size
Culture at 30˚C
 Requires 2 – 3 days to grow, white waxy / wooly

Coccidioides immitis
Septated hyphae with chains of thick walled barrel
shaped arthroconidia with dead cells in between –
arthroconidia inhaled in nature

in culture from media
incubated at both 30* and 35*C – No yeast phase

Coccidioides immitis

Malbranchea species is look alike fungus
Thick walled spherules (10 – 80 uM) with
endospores NO YEAST CELLS
 All stages of development / fragmented spherules
 Granulomatous inflammation with caseation

Coccidioides immitis
Rhinosporidium seeberi spherules - > 80 uM
Larger than Coccidioides spherules
Rhinosporidium seeberi spherules - > 80 uM
Larger than Coccidioides spherules
Culture @ 37˚C
 Slow (3- 4 weeks) waxy coral-like yeast
 Large yeast (10 – 30uM) with multiple daughter
buds (2 – 10 uM)

Paracoccidioides brasiliensis
Young (L)
Old (R)
Young (L)
Old (R)
MOLD PHASE
 30*˚C growth in 3 -5 days
 Turns brown to black over time

Sporothrix schenckii
MOLD FORM (30 C)
Septate hyphae with conidia in daisy wheel
pattern

Sporothrix schenckii
MOLD FORM (30 C)
Septate hyphae with conidia in daisy wheel
pattern

Sporothrix schenckii
YEAST PHASE

At 37˚C small oval yeast cells, elongated 2 – 5 μM, described as cigar bodies

Sporothrix schenckii
YEAST PHASE

At 37˚C small oval yeast cells, elongated 2 – 5 μM, described as cigar bodies

Sporothrix schenckii
Sporothrix schenckii

Asteroid body known as Splendore-Hoeppli phenomenon can be seen – also seen in:
 Zygomycetes (mucorales)
 Aspergillus
 Blastomycosis
 Candida
Penicillium marneffei
Brown colonies on Birdseed agar

C. neoformans
Cryptococcus gatti

In culture and staining identical to C.
neoformans except for L Canavanine glycine
bromthymol blue medium – C. gatti = blue
C.neoformans = colorless
Paroxysmal cold hemoglobinuria, with erythrophagocytosis; the arrow points to a red cell that has been phagocytosed by a neutrophil.
Macrocytic anemia resulting from congenital dyserythropoietic anemia type 1 also yields a characteristic blood smear, with striking poikilocytosis

CDA type I is transmitted by both parents autosomal recessively and usually results from mutations in the CDAN1 gene.

CDA type I is characterized by moderate to severe anemia. It is usually diagnosed in childhood or adolescence, although in some cases, the condition can be detected before birth. Many affected individuals have yellowing of the skin and eyes (jaundice) and an enlarged liver and spleen (hepatosplenomegaly). This condition also causes the body to absorb too much iron, which builds up and can damage tissues and organs. In particular, iron overload can lead to an abnormal heart rhythm (arrhythmia), congestive heart failure, diabetes, and chronic liver disease (cirrhosis). Rarely, people with CDA type I are born with skeletal abnormalities, most often involving the fingers and/or toes
Erythrocyte with prominent basophilic stippling (arrow), a result of lead poisoning
Burkitt’s lymphoma, with three basophilic vacuolated lymphoma cells
Hypogranular promyelocytic leukemia is shown in Panel B, with two characteristic bilobed leukemic promyelocytes
Cryoglobulin deposition in a blood sample from a patient with hepatitis C virus infection
HbC - clams
HEINZ BODY

require supravital dye
- crystal violet (reticulocyte stain)

• causes:
- denatured/oxidized Hb
- G6PD deficiency
- unstable hemoglobins
• bite cells have had them bitten out