
Full text loading...
Category: Clinical Microbiology
Specific Test Procedures and Algorithms, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555815967/9781555814540_Chap05-1.gif /docserver/preview/fulltext/10.1128/9781555815967/9781555814540_Chap05-2.gifAbstract:
This section focuses on microscopic techniques and calibration of the microscope and algorithms for the ova and parasite (O&P) examination. Direct wet fecal smear, sedimentation concentration, flotation concentration methods used for the results and laboratory reports and procedure reminders and limitations are briefly discussed. Specialized stains for Coccidia and Microsporidia are discussed using different staining methods. Modified trichrome stain for Microsporidia is reviewed for the clinical assay. Antigen-based fecal immunoassays have several significant advantages over other methods currently used for diagnosis of amebiasis. Different stains are analyzed for the parasites examination. Several concentration techniques such as buffy coat concentration, knott concentration and membrane filtration concentration are discussed. The section also provides a brief outline of the procedure for processing fresh stool for the O&P examination.
Full text loading...
Ocular micrometer, top scale; stage micrometer, bottom scale. Reprinted from Diagnostic Medical Parasitology, 5th ed.
Method of scanning a direct wet film preparation with the 10× objective. (Illustration by Nobuko Kitamura.) Reprinted from Diagnostic Medical Parasitology, 5th ed.
Fecal concentration procedures: various layers seen in tubes after centrifugation. (A) Formalin-ether (or ethyl acetate). (B) Zinc sulfate (the surface film should be within 2 to 3 mm of the tube rim). (Illustration by Sharon Belkin.)
Method used to remove surface film in the zinc sulfate flotation concentration procedure. (A) A wire loop is gently placed on (not under) the surface film. (B) The loop is then placed on a glass slide. (Illustration by Nobuko Kitamura.) Reprinted from Diagnostic Medical Parasitology, 5th ed.
Culture methods for the recovery of larval-stage nematodes; Harada-Mori tube method and petri dish culture method. (Illustration by Nobuko Kitamura.) Reprinted from Diagnostic Medical Parasitology, 5th ed.
Baermann apparatus. (Illustration by Nobuko Kitamura.) Reprinted from Diagnostic Medical Parasitology, 5th ed.
Agar culture method for Strongyloides stercoralis. (1) Agar plates are prepared; (2) agar is dried for 4 to 5 days on the bench top; (3) plates are stored in plastic bags; (4) fresh stool is submitted to the laboratory; (5) approximately 2 g of stool is placed onto an agar plate; (6) the plate is sealed with tape; (7) the culture plate is incubated at 26 to 33°C for 2 days; (8) the plate is examined microscopically for the presence of tracks (bacteria carried over the agar by migrating larvae); (9) 10% formalin is placed onto the agar through a hole made in the plastic by hot forceps; (10) material from the agar plate is centrifuged; (11) the material is examined as a wet preparation for rhabditiform or filariform larvae (high dry power; magnification, ×400). (Illustration by Sharon Belkin.) Reprinted from Diagnostic Medical Parasitology, 5th ed.
Method of thin blood film preparation. (A) Position of spreader slide; (B) well-prepared thin film. Arrows indicate the area of the slide used to observe accurate cell morphology. (Illustration by Nobuko Kitamura.) Reprinted from Diagnostic Medical Parasitology, 5th ed.
Method of thick-thin combination blood film preparation. (a) Position of a drop of EDTA-blood; (b) position of the applicator stick in contact with blood and glass slide; (c) rotation of the applicator stick; and (d) completed thick-thin combination blood film prior to staining. (Illustration by Sharon Belkin.) Reprinted from Diagnostic Medical Parasitology, 5th ed.
Procedure for processing fresh stool for the O&P examination
Procedure for processing liquid specimens for the O&P examination
Procedure for processing preserved stool for the O&P examination—two-vial collection kit
Procedure for processing SAF-preserved stool for the O&P examination
Use of various fixatives and their recommended stains
Ordering algorithm for laboratory examination for intestinal parasites
Procedure for processing blood specimens for examination
Body site, specimen, and recommended stain(s) a
Approaches to stool parasitology: test ordering
Laboratory test reports: optional comments a,b
Parasitemia determined from conventional light microscopy: clinical correlation