SECTION 1 PART 2 Flashcards
is essential for the isolation and proper diagnosis of infection.
Proper collection of fecal sample
The following should be considered:
- Container: [?] (for physical examination of the specimen)
- Avoid contamination with [?]
- Label - [?]
sterile, disposable, wide mouth with tight-fitting lid, transparent
urine, water and soil
side of the container, not on the lid
Submission of specimen:
- liquid
- formed
- watery
30 mins - liquid
1 hr - formed
15-30 mins - watery
- Handle carefully because it is a potential source of infection unsuitable samples from patients receiving: UNSUITABLE SAMPLES FROM PATIENTS RECEIVING
a. Barium
b. Oil
c. Bismuth
d. Kaolin
e. Antibiotics
TYPES of FECAL SPECIMEN
- Liquid
- Soft
- Formed
– either diarrheic or saline-purged
- Liquid
: process of administering saline that are ways to promote evaporation of watery stool
saline-purged
a) Physical PRESERVATION
- Room temperature
- Refrigeration
b) Chemical PRESERVATION
- Polyvinyl Alcohol (PVA)
- 5-10% formalin
- Merthiolate-Iodine-Formalin (MIF) or Thimerosal Iodine Formalin (TIF)
- Schaudinn’s Fixative
- Sodium Acetate - Acetic Acid Formalin (SAF)
Refrigeration (?)
2 to 8 degrees; only formed to semi-formed
used for the preservation of stained fecal+ smears
Polyvinyl Alcohol (PVA)
aka Modified Schaudinn’s (with fixative)
Polyvinyl Alcohol (PVA)
Polyvinyl Alcohol (PVA) components:
schaudinn’s fluid: 93.5 ml
glycerol: 1.5 ml
glacial acetic acid: 5 ml
polyvinyl alcohol (powder): 5 g
*Quality control: discard if cloudy
Polyvinyl Alcohol (PVA)
For concentration techniques or direct fecal smear
5-10% formalin
For cysts, helminthes and larvae
5-10% formalin
5-10% formalin
cysts:
helminthes and larvae:
stock solution:
cysts: 5%
helminthes and larvae: 10%
stock solution: 40%
- may or may not have iodine
Direct fecal smear
Not sufficient for preparing permanent stained fecal smears
5-10% formalin
*Quality control: Heat at 60°C before use (temperature favors development of helminth)
5-10% formalin
Merthiolate-Iodine-Formalin (MIF) or Thimerosal Iodine Formalin (TIF)
For bulk feces, the solution is mixed in the proportion of (?) and (?) for a gram of fecal material
9.4 ml MIF
0.6 ml Lugol’s
For fresh materials and those recovered from intestinal mucosal linings
Schaudinn’s Fixative
For permanent staining
Schaudinn’s Fixative
without mercuric chloride; lipid fixative with a long shelf-life
Sodium Acetate - Acetic Acid Formalin (SAF)
image of the organism if not sharp after staining
Sodium Acetate - Acetic Acid Formalin (SAF)
IMPORTANCE OF FECALYSIS
1. To detect the presence of [?]
2. For the detection of evidence of malfunction of some parts of the [?]
3. For the detection of [?]
4. For the detection of [?]
5. Used as a clue in [?]
intestinal parasites
GIT, liver and pancreas
GIT bleeding
excessive fats in stool (steatorrhea)
medical and surgical diagnosis.
Liver damage: [?] gives the normal brown color.
Stercobilin
may indicate billiary obstruction
Acholic (gray/no color)
- upper GIT bleeding (red)
Hematochezia
- black
Melena
Form and Consistency Normal:
soft to formed
Form and Consistency Variations:
seen in diarrhea and administration of saline cathartic
a) Very soft and watery
px taking taxatives
a) Very soft and watery
constipation due to lack of mucus
b) Excessively hard and scybalous
: goat-droppings
scybalous
cholera
c) Rice water stool
- Does not flow on tilting due to trapped gas
Mushy
Sprue of excessive carbohydrate fermentation
Mushy
- liquid and consist mostly of water
Diarrheic
early typhoid
d) Pea soup stool
syphilis, spastic colitis and obstruction at the lower portion of the colon (rectum or anus)
e) Flattened or ribbon like
fibrocystic disease of the pancreas
f) Butter like
excessive carbohydrate fermentation
g) Gaseous and fermentative
Color Normal:
light brown to dark brown due to stercobilin
Color Variations:
Oxidized [?] gives off bilirubin
stercolobilinogen
due to administration of santonin (antihelminthic) and senna (antihelminthic or pang purge from plant)
a) Yellow
seen after ingestion of Barium meals
b) Light clay or putty color (acholic/colorless)
(used before x-ray)
Barium
bleeding in the lower GIT (hematochezia)
c) Reddish or bloody
undigested beets and tomatoes
c) Reddish or bloody
bleeding in the upper GIT
d) Dark red/chocolate brown
intense intake of coffee, chocolate, cherries, and black berry
d) Dark red/chocolate
associated with digestion of blood due to bleeding in the upper GIT
e) Black/tarry
increased intake of bismuth and charcoal
e) Black/tarry
amoebiasis
f) Greenish
mucoid
f) Greenish
fishy order
f) Greenish
vegetable ingestion (green stool w/o amoebiasis)
f) Greenish
calomel, mercury, chloride
f) Greenish
cocoa and chocolate produce dark a stool
g) Gray
infants (normal) and adults (lack of bilirubin derivatives)
h) Golden yellow/yellowishwhite
bizarre colors, whitish discoloration, blue and orange red
i) Miscellaneous
(drug-intake)
bizarre colors
blue –
methylene blue/dithiozaline
orange-red –
pyridium
Odor Normal:
foul to offensive due to indole, skatole and butyric acid
Abnormal odors:
found in ulcerative and malignant tumor of the lower bowel
a) Putrid odor
indicates gas formation, fermentation of carbohydrate, unabsorbed fatty acids
b) Sour/rancid odor
usually in alkaline stools, putrefaction of undigested protein.
c) Extremely foul odor
antibiotic intake kills both pathogenic and normal flora causing alkaline ph of stool
c) Extremely foul odor
– not routine in the lab; blood not visible to the naked eye and only detected by chemical means
Occult blood
Laboratory Examination for Occult Blood:
a) Benzidine test
b) Guaiac;s test
c) Hematest
Laboratory Examination for Occult Blood - most commonly used
Guaiac;s test
General Principle: The peroxidase-like activity of blood (due to peroxidase contained in the heme portion of hemoglobin) decomposes [?] to produce [?]. The liberation of [?] causes the oxidation of the colorless chromogen into a colored compound (blue)
H2O2
water and oxygen
oxygen
Patient Preparation: meat free diet for [?] prior to the test
3-5 days
Cause False (+) Results
- Peroxidase activity substance or fecal material
- Iron in the diet
- Myoglobin in ingested meat
px should not eat:
melon, fresh uncooked broccoli, horse radish, cauliflower, and turnip
Cause False (-) Results
- Large amount of Vitamin C
- Breakdown of blood and its constituents
- Hemorrhage in the Upper GIT 4, Technical errors (personnel, reagent problem or quality control)
strong reducing agent that blocks the activity of Guaiac, Hematest, and Benzidine
Vitamin C
The following structures may be seen microscopically:
– seen in watery or diarrheic sample
a) Trophozoites and cysts of amoeba
– seen in formed stool
b) Helminth eggs and larvae
– depends on diet
g) Plant cells, pollen grain and spores
– from eosinophil and basophil; evidence of parasitic infection
l) Charcot-layden crystals
TECHNIQUES
- DIRECT FECAL SMEAR
- KATO THICK SMEAR (KTS)
- CONCENTRATION TECHNIQUES
- STAINING METHODS
- SPECIAL RECOVERY METHODS
- CULTURE METHODS
- ANIMAL INOCULATION TESTS
- XENODIAGNOSIS
– simplest and most frequently used
DIRECT FECAL SMEAR
- for the observation of the motility of trophozoites
a) 0.85% sodium chloride/NSS
is used if there is no stain used
Normal saline
– for protozoan cysts and helminth ova
b) D’antonis solution/Lugol’s Iodine
• For large scale examination
DIRECT FECAL SMEAR
• Satisfactory for all kinds of helminth eggs
DIRECT FECAL SMEAR
•Unsuitable for diarrheic stools
DIRECT FECAL SMEAR
•Unsuitable for protozoan cysts and trophozoites
DIRECT FECAL SMEAR
- reagent used kills cysts and thropozoites that will make them look like contaminants
DIRECT FECAL SMEAR
DIRECT FECAL SMEAR Reagents:
a) 0.85% sodium chloride/NSS
b) D’antonis solution/Lugol’s Iodine
KATO THICK SMEAR (KTS) Reagents:
Distilled water 100 ml
Glycerin 100 ml
3% malachite green 1 ml
- green cellophane was formerly used; to prevent eye strain
3% malachite green
Use cellophane as cover slip
KATO THICK SMEAR (KTS)
KATO THICK SMEAR (KTS) Clearing time:
1 hour
- used in the detection of a small number of parasites which are not detected using DFS
CONCENTRATION TECHNIQUES
– uses either specific gravity or centrifugation
a) Sedimentation Method
a) Sedimentation Method Types
sediment - settles at the bottom; for all types of eggs especially operculated (with cap)
a) Sedimentation Method
– concentrates helminth eggs, larvae and protozoan cysts
• Formalin-Ether techniques
: fixative
formalin
: removes lipids to clear the sediments
ether
– used for formed stools; applicable for helminth eggs and larvae
• Acid-Ether Sedimentation
: clearing agent
Acid-ether
– time-consuming
• Simple sedimentation
- for concentration of microfilariae’ utilizes venous blood as specimen
• Knott Concentration Technique
To diagnose elephantiasis
• Knott Concentration Technique
- settles above; not suitable for operculated ova (D. Latum - tapeworm; Fasciola - liver flukes)
b) Flotation method
✓ Allows the separation of helminth eggs, protozoan cysts and larvae (1.05 – 1.15) using chemical solutions of higher specific gravity (1.12-1.21)
b) Flotation method
✓ Eggs and cysts float to the surface of the solution while fecal materials sink to the bottom
b) Flotation method
✓ Superior to sedimentation for concentrating cysts and eggs other than operculated, schistosomal and infertile Ascaris eggs
b) Flotation method
b) Flotation method Optimal time:
5 to 20 mins (after 30 minutes destroys/disintegrates the cysts)
- valuable method for concentrating cysts and eggs
• Zinc Sulfate centrifugal flotation technique
• Zinc Sulfate centrifugal flotation technique
- specific gravity:
[?] (hydrometer)
[?] formalinized feces
1.18
1:20
- Cryptosporidium (rounded oocysts)
• Sugar Flotation Technique/Sheather’s Sugar Flotation
• Sugar Flotation Technique/Sheather’s Sugar Flotation COMPOSITION:
Sucrose (500g), Tapwater (320 mL), Phenol (6.5g)
: to prevent mold formation
- Phenol
- uses sodium chloride solution
• Wilie’s Brine
• Wilie’s Brine COMPOSITION:
NaCl (40g) + Distilled water (100mL)
- STAINING METHODS
• 1% Isotonic Eosin Solution & 2% Brilliant Cresyl Blue
- Trophozoites-
- Background-
- Trophozoites- blue green
- Background- pink
• D’Antonis
• 1% Isotonic Eosin Solution & 2% Brilliant Cresyl Blue
• Eosine in saline
• Buffered Methylene Blue (ex. Nairs Methylene Blue)
b) Permanent Staining
• Gomori’s Trichrome Stain
• Lawless’ Permanent Mount Stain
• Modified Acid-Fast stain
• Iron Hematoxylin Stain
• MIF Fixative stain ( Merthiolate iodine formaldehyde)*
• Chlorazol Black E*
• Modified Kohn’s*
- Wheatley’s modification
• Gomori’s Trichrome Stain
- For intestinal protozoa
• Gomori’s Trichrome Stain
- Rapid method of staining trophozoites and cysts
• Lawless’ Permanent Mount Stain:
• Lawless’ Permanent Mount Stain
- Protozoa –
blue to purplish color
- Cryptosporidium, Isospora and Cyclospora
• Modified Acid-Fast stain
- Two separate stains: Carbol fuchsin and methylene blue
• Modified Acid-Fast stain
- lacks specificity
• Modified Acid-Fast stain
- diagnosis of Trichomonas
• MIF Fixative stain ( Merthiolate iodine formaldehyde)*
- An acid dye, used as a fat and general tissue stain, and to stain protozoa in fecal smears or in tissues.
• Chlorazol Black E*
- modification of the chlorazol black E staining technique
• Modified Kohn’s*
- SPECIAL RECOVERY METHODS
a) Cellulose Tape Preparation/Graham Scotch Tape Method
b) Egg Count Technique
c) Egg Hatching Technique
b) Egg Count Technique Methods
- Direct Smear Egg Count (Method by Beaver)
- Dilution Egg Count
- Thick Smear Egg Count
- Dilution-Filtration Egg Count
✓ Enterobius vermicularis and Taenia
Cellulose Tape Preparation/Graham Scotch Tape Method
✓ Collection: morning before the patient washes or defecates
Cellulose Tape Preparation/Graham Scotch Tape Method
✓ Commercial collection kits are available
Cellulose Tape Preparation/Graham Scotch Tape Method
Tongue depressor attached w/ glass slide and scotch tape
Cellulose Tape Preparation/Graham Scotch Tape Method
– provides an estimate of worm burden
Egg Count Technique
✓ Determines the degree of infection (light, moderate or heavy)
Egg Count Technique
✓ For recovery of hookworms, Ascaris and Trichuris
Egg Count Technique
- Direct Smear Egg Count (Method by Beaver)
- 1.5 mg feces (?) = eggs per gram (epg)
- 2.0 mg feces (?) = epg
667
500
– uses 0.1 N NaOH - Stoll’s Egg Counting Technique
- Dilution Egg Count
– KTS for schistosomes
- Thick Smear Egg Count
– Schistosomes
- Dilution-Filtration Egg Count
is a laboratory tool used to determine a given parasite’s resistance to extant drug therapy.
Egg Hatching Technique
CULTURE METHODS PURPOSES:
✓ For accurate detection of the organisms as a [?] to other methods
✓ For obtaining a rich yield of organisms to be used as [?] in immunologic diagnosis [?]
✓ For in-vitro screening of [?]
✓ For investigating the [?] of organisms
✓ As a source for inoculating [?]
supplement
antigen
drugs
physiology
susceptible experimental animals
CULTURE METHODS for PROTOZOA
a) Balamuth’s Monophasic Medium
b) Boeck & Drbohlav’s Diphasic as Modified by Dobell and Laidlaw
c) Cleveland & Collier’s
d) Trussel and Johnson’s medium (& Fineburg and Whittington)
e) Axenic Culture Method
- Entamoeba histolytica and Balantidium coli
Balamuth’s Monophasic Medium
- E. histolytica
Boeck & Drbohlav’s Diphasic as Modified by Dobell and Laidlaw
- Concentrate from saline centrifugal sedimentation of feces rather than the feces is recommended.
Boeck & Drbohlav’s Diphasic as Modified by Dobell and Laidlaw
- Use of whole hen’s eggs
Boeck & Drbohlav’s Diphasic as Modified by Dobell and Laidlaw
- highly specific for E. histolytica
Cleveland & Collier’s
Isolation of Trichomonas vaginalis
Trussel and Johnson’s medium (& Fineburg and Whittington)
- histolytica
Axenic Culture Method
CULTURE METHOD FOR HOOKWORMS AND STRONGYLOIDES
A. Coproculture
B. Harada-Mori or Test tube culture method
CULTURE METHOD for LEISHMANIA & TRYPANOSOMES
a) Novy, MacNeal and Nicole (NNN) Diphasic
b) Cellular Media
- (+) stool samples are mixed with moisture soil/granulated charcoal for the development of larvae
Coproculture
- BAERMANN METHOD or funnel method
A. Coproculture
- (+) positive stool sample is applied to the filter paper, and immersed with boiled distilled water
B. Harada-Mori or Test tube culture method
Strongyloides (strong) follows an upward movement unlike hookworm that goes downward
B. Harada-Mori or Test tube culture method
- Best medium
Novy, MacNeal and Nicole (NNN) Diphasic
- For Trypanosoma cruzi and Toxoplasma
Cellular Media
• RBCs that have been coated with antigen are allowed to react with the test serum
Indirect Hemagglutinat ion (IHA)
• The red cells agglutinate in the presence of specific antibady
Indirect Hemagglutinat ion (IHA)
• Bentonite, latex particles or the organism is exposed to the test serum
Flocculation or Agglutination
• Agglutination indicates the presence of a specific antibody
Flocculation or Agglutination
• Microscopically visible parasites fixed on a slide are allowed to react with test serum
Indirect Fluorescent Antibody (IFA)
• The slide is washed and treated with AHG with fluorescein (Sandwich Method)
Indirect Fluorescent Antibody (IFA)
– very sensitive in several cases; requires concentrated
antigen
Gel Diffusion(Ouchterlony) and Countercurent Electrophoresis (CEP)
• Test serum is placed in a well adjacent to the antigen
Gel Diffusion(Ouchterlony) and Countercurent Electrophoresis (CEP)
• Both reactant are allowed to diffuse toward each other through the agar
Gel Diffusion(Ouchterlony) and Countercurent Electrophoresis (CEP)
• Formation of precipitates/band between the
Gel Diffusion(Ouchterlony) and Countercurent Electrophoresis (CEP)
- color reaction is measured spectrophotometrically
Enzyme linked immunosorbe nt assay (ELISA)
• Test serum is allowed to react with an antigen (coat the surface of plastic well).
Enzyme linked immunosorbe nt assay (ELISA)
• Anti-human IgG antibody conjugated with enzyme is added.
Enzyme linked immunosorbe nt assay (ELISA)
• If a specific antibody was present in the test serum, the anti-human IgG antibody labeled with an enzyme attaches to the antigenantibody complex.
Enzyme linked immunosorbe nt assay (ELISA)
The addition of a suitable substrate generates a visible color reaction
Enzyme linked immunosorbe nt assay (ELISA)
Enzyme linked immunosorbe nt assay (ELISA) spp
T. gondii, T. vaginalis, leishmaniasis, malaria, schistosomiasis etc.
✓ Animal Used: hamster
Leishmania
✓ Specimen: aspirates from biopsy materials from cutaneous ulcers, lymph nodes, spleen, liver
Leishmania
Leishmania Specimen Collection
intravenous, intramuscular, subcutaneous, intradermal, intraperitoneal, intracerebral, intranasal
✓ Animal Used: Guinea pigs or white rats (Trypanosoma gambiense and T. rhodesiense)
Trypanosoma
✓ White mice (?)
Trypanosoma cruzi
✓ An experimental bug (vector) is allowed to take a blood meal from the patient
XENODIAGNOSIS
✓ The intestinal contents of the bug is assessed for the presence of diagnostic stages of the parasite
XENODIAGNOSIS
XENODIAGNOSIS Ex. T. cruzi from an
assassin bug or kissing bug
: The trichrome technique of Wheatley for fecal specimens is a modification of Gomori’s original staining procedure for tissue.
Gomori’s Trichrome Stain
It is a rapid, simple procedure which produces uniformly well stained smears of the intestinal protozoa, human cells, yeast cells, and artifact material in about 45 min or less.
Gomori’s Trichrome Stain
: A rapid permanent-mount stain technic for the diagnosis of the intestinal protozoa
Lawless’ Permanent Mount Stain
Use of the modified Ziehl-Neelsen stain for faecal smears has already been established for coccidian protozoa, in particular, oocysts of Cryptosporidium species, but it is also useful to confirm the presence of oocysts of Isospora belli and Cyclospora cayetanensis
• Modified Acid-Fast stain
- used for most of the original morphological descriptions of intestinal protozoa found in humans.
• Iron Hematoxylin Stain
- On oil immersion power (1,000 x ), one can examine the diagnostic features used to identify the protozoan parasite.
• Iron Hematoxylin Stain
can be used with either fresh, SAFpreserved, or PVA-preserved specimens.
• Iron Hematoxylin Stain
✓ Fresh eggs are incubated from the parasite of interest and serial dilutions of the drug of interest are applied.
Egg Hatching Technique
The percentage of eggs that hatch or die is determined at each concentration and a drug response curve may be plotted.
Egg Hatching Technique
The data can then be transformed and analysed to give further statistics such as an ED50.
Egg Hatching Technique
✓ This technique is labour intensive, expensive and can take some time, however an egg hatch assay will give and accurate and reliable
Egg Hatching Technique
- All liquid medium commonly used for the isolation and maintenance of Entamoeba histolytica and some other intestinal protozoa.
Balamuth’s Monophasic Medium
- It is satisfactory for Balantidium coli, although the quality and amount of starch may need to be adjusted
Balamuth’s Monophasic Medium
- Use of egg yolk
Balamuth’s Monophasic Medium
- Egg slant
Boeck & Drbohlav’s Diphasic as Modified by Dobell and Laidlaw
- highly specific for E. histolytica , which grows luxuriantly on this medium.
Cleveland & Collier’s
Other intestinal amoebae do not grow readily on this medium.
Cleveland & Collier’s
The technique of overlaying the medium with fresh sterile horse serum-saline mixture, as reported by
Cleveland & Collier’s
was reported to be the best method of isolation of E. histolytica .
Cleveland & Collier’s
- Proteose peptone and infusion from liver provide amino acids and other nitrogenous substances that support growth of E. histolytica .
Cleveland & Collier’s
- Sodium chloride maintains the osmotic balance of the medium and sodium a-glycerophosphate acts as a phosphorous source.
Cleveland & Collier’s
has been an essential component of numerous immunological and biochemical studies
Axenic Culture Method
- Monophasic clear liquid for rapid growth of dense populations of amebae
Axenic Culture Method
- Use of sterile defibrinated rabbit blood
Novy, MacNeal and Nicole (NNN) Diphasic
amoebiasis, Chaga’s disease, malaria, toxoplasmosis, cystisercosis, hydatid cyst, filariasis, schistosomiasis
Indirect Hemagglutinat ion (IHA)
Leishmaniasis, Chaga’s disease
Flocculation or Agglutination
Detect amebiasis and fascioliasis infections
Gel Diffusion (Ouchterlony) and Countercurent Electrophoresi s (CEP)
✓ Modification of the standard ELISA for increased sensitivity and specificity in detecting antibodies of the IgM class to Toxoplasma
Antibody Capture or Double Sandwich ELISA
✓ Plastic well are coated with anti-human IgM antibodies
Antibody Capture or Double Sandwich ELISA
✓ After washing, the test serum is added followed by further washing and addition of the test antigen
Antibody Capture or Double Sandwich ELISA
✓ The final reagent is an antigen-specific antibody to which the color reagent has been conjugated
Antibody Capture or Double Sandwich ELISA
✓ The plates are read spectrophotometrically
Antibody Capture or Double Sandwich ELISA
✓ This method can be used for assay of parasitespecific IgE antibodies by starting with anti human IgE
Antibody Capture or Double Sandwich ELISA
is based on the fact that live Toxoplasma tachyzoites can actively take up methylene blue dye from the culture medium, whereas parasites that are killed because of complement-mediated lysis do not take up the dye and remain colorless.
SabinFeldman Dye Test
- Specifically designed for the diagnosis of Toxoplasmosis
SabinFeldman Dye Test
is a serological test used for diagnosis of schistosomiasis japonica.
Circumoval Precipitin Test (COPT)
formation of the circumoval precipitin by serum from infected humans.
Circumoval Precipitin Test (COPT) Soluble egg antigens of Schistosoma japonicum block the
was used to monitor purification of the soluble egg antigens of S. japonicum.
circumoval precipitin inhibition
is a very sensitive in vitro assay technique used to measure concentrations of antigens by use of antibodies.
Radioimmuno assay (RIA)
As such, it can be seen as the inverse of a radiobinding assay, which quantifies an antibody by use of corresponding antigens
Radioimmuno assay (RIA)
is a radioimmunoassay test to detect specific IgE antibodies to suspected or known allergens for the purpose of guiding a diagnosis about allergy
Radioallergosorbent Test (RAST)
- In this test, the parasite antigen is first bound to an inert sorbent or matrix to which the test serum is allowed to react.
Radioallergosorbent Test (RAST)
After washing, radio-labeled antibody (IgE or IgG) is added to the sorbent.
Radioallergosorbent Test (RAST)
After another washing to remove excess labeled antibody, the remaining radioactivity is a measure of antigen-specific IgG or IgE in the test serum
Radioallergosorbent Test (RAST)
CSF and serum may be used.
Immunoblotting/Western Blot
By using electrophoresis technique, the DNA containing portion of the patient sample is transferred to a polyacrylamide gel.
Immunoblotting/Western Blot
This process results in the separation of protein antigens in the gel.
Immunoblotting/Western Blot
A blotting technique is employed to transport the proteins onto a paper.
Immunoblotting/Western Blot
Giardiasis
Immunoblotting/Western Blot
Three ingredients is necessary to for performing the first phase: patient serum, a commercial antigen source, known amount of complement.
Complement Fixation (CF)
The complement is “fixed” by the antibodies present in the serum.
Complement Fixation (CF)
In the 2nd phase, sensitized sheep’s rbc is added to the mixture.
Complement Fixation (CF)
The absence of free complement prevents lysis of these cells ( positive). If the patient sera does not contain Ab, complement is free to lyse ( negative)
Complement Fixation (CF)
leishmaniasis, Chaga’s disease, pneumocystosis, paragonimiasis
Complement Fixation (CF)
Over the years, parasites which were once considered commensal have evolved to become
human pathogens
During this time, tremendous knowledge was obtained of the epidemiology, parasite-host relationships, life cycles, disease processes and symptoms, treatment, and prevention and control of
parasites
In addition, parasites are classified based on their individual
characteristics
Traditional as well as new methodologies for parasite identification allow for
accurate laboratory diagnosis
is an interesting and exciting field of the clinical laboratory sciences.
Parasitology
The continued development of high-tech, highly sensitive[?] provides the key to the future of parasitology.
parasite test methodologies
Because it is highly unlikely that parasites will totally be eradicated in the near future, competent practitioners educated in the field of parasitology are essential to ensure proper
parasite identification.
preservation of trophozoites and cysts
Polyvinyl Alcohol (PVA)
