Title: Acanthamoeba troph motility wet mount Entamoeba histolytica troph iodine wet mount
1Acanthamoeba troph - motility wet mount
Entamoeba histolytica troph - iodine wet mount
?
2Diagnostic procedures continued
- 2. Concentrates same as 1. but concentrated
material is easier to see. Problem is that
debris is concentrated as well. Conduct like
direct wet mount OR preserve with formalin for
examination at a later time. - a) flotation see page 1076
- b) sedimentation gravity or centrifugation,
decant super -
- 3. Permanent stained smears 1 for protozoan
morphology/ID - sample smeared on slide, chemically fixed,
then stained - a) Fe hematoxylin DNA PO4- groups tricky
but good - b) Trichrome - gt1 dye binds basic / () charged
things with - varying affinity 1 stains tissue, 1
stains border, etc. - easiest method gives good results for
most protozoans - c) modified acid fast - long C chain acids
Crypto cysts - d) Giemsa - DNA PO4- groups used for blood
- images?
3Giardia lamblia cyst Iron hemtoxylin stain
Enatamoeba histolytica trophs
- trichrome stain
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4Plasmodium trophs in RBCs - Giemsa stain
Cryptosporidium cysts - modified acid fast
?
5Diagnostic procedures continued
- miscellaneous - see 1078, 1079
- duodenal aspirates for Giardia Strongyloides
larvae - cellophane tape preparations for Enterobius
- tissue biopsies for Leishmania
- wet blood smear for hemoflagellate parasites
- vaginal swabs for Thichomonas vaginalis
unstained direct wet mount performed within 30
minutes and examined for pear-shape troph,
undulating membrane and darting motility -
6Sample preservatives / fixatives
- Why to stabilize sample (maintains morphology
and prevents further development of protozoan
cysts certain juvenile trophs and helminth eggs
larvae) if examination must be delayed beyond
specified time limits due to need for sample
transport, work load prevents immediate exam,
etc. - Each fixative has its particular intended uses
its limitations - Some commonly used products
- a)PVA polyvinyl alcohol Hg or non-Hg based
??? - Preferred product for preserving and fixing
permanent smears of protozoan cysts trophs,
especially when they are to be stained with
trichrome or hematoxylin. - Inferior for concentrates.
- ?
7Sample preservatives/fixatives continued
- b)Formalin
- preserves all helminth forms protozoan cysts
(only) - is preferred for helminth eggs larvae
- preferred preservative for concentrates
- unsuitable for permanent smears
- pungent odor carcinogenic
- c)SAF sodium acetate/formalin
- vs PVA longer shelf life
- vs formalin suitable for concentrates
permanent smears - hematoxylin stain preferred to trichrome when
SAF is used - d)MIF?
- lab?
8Host-parasite definitions see pg 1081
Intermediate host host in which some parasite
development may occur, but sexual maturity is NOT
reached. This host is often the reservoir and/or
the vector. Plasmodium is weird! Definitive
host hosts the parasite in the sexually mature
form, which is the pathogenic form in most cases.
This host may also be the reservoir and/or the
vector, or the only host. Reservoir (host)
organism in which the parasite normally resides
when not in, or in addition to the human host.
This organism may also be a host and or
vector. Vector organism that transmits the
parasite to the human host. This is often the
intermediate host, but not always. Consider the
examples on the table which (intermediate or
definitive) is the vector? see table?