Bacteriology
- Common Bacteria
Bacteriologic Methods
- Smears
- Gram's Stain
- Reading and Reporting Smears
Serology
- Rapid Plasma
Reagin (RPR) Card Test for Syphilis
- Monosticon
Slide Test for Infectious Mononucleosis
Fungus (Pl. Fungi)
- Potassium
Hydroxide (KOH) Preparation for Identification of Fungi
Blood Grouping
- Agglutination
- Rh Factors
- Technique for Blood
Grouping and Typing
Responsibilities in
the Clinical LaboratoryEthics in the LaboratoryReferences
In this chapter we will discuss the classification of bacteria, some of the more common
pathogens, and the preparation, staining, and examination of specimens. Also included are
basic serologic tests, such as the rapid plasma reagin (RPR) card test for syphilis and
the Monosticon slide test for infectious mononucleosis, the potassium hydroxide (KOH)
preparation for the identification of fungi, and the principles and procedures for blood
grouping and typing.
Bacteriology
Bacteriology is the study of bacteria. Of
primary interest to hospital corpsmen is medical bacteriology, which deals with the
bacteria that cause disease in man.
Bacteria are prokaryotic microorganisms of the kingdom Protista. They reproduce
asexually by transverse binary fission in which the cell divides into two new cells. They
are found almost everywhere, with the human body harboring vast numbers. Many bacteria are
beneficial and essential to human life, only a few are harmful to man.
Since there are thousands of different bacteria, a method of classification is
essential. Bacteria are classified according to their (1) disease-producing ability, (2)
growth requirements, (3) morphologic characteristics, (4) colonial morphology, (5)
biochemical activity, (6) toxins, and (7) Gram's stain reaction.
The disease producing ability is termed as either pathogenic or nonpathogenic.
Pathogens are bacteria that cause diseases and nonpathogens are the harmless bacteria.
Many bacteria that are essential to our body are called common or normal flora in their
proper environment. For example, alpha streptococcus in the throat is common flora, but
when it is found elsewhere, such as in the blood stream, possibly as a result of tooth
extraction, it may cause septicemia and endocarditis.
The four growth requirements are (1) temperature, (2) oxygen, (3) nutrition, and (4)
moisture. Temperature requirements are divided into three categories.
- Psychrophilic-those that reproduce best at 15° to 20° C
- Mesophilic-those that reproduce best at 20° to 45° C
- Thermophilic-those that reproduce best at 50° to 55° C
The oxygen requirements vary according to the amount of oxygen needed for an organism
to grow or reproduce. Aerobes are those organisms that reproduce in the presence of
oxygen. Obligate aerobes are those that grow only in the presence of free oxygen.
Anaerobes are organisms that do not reproduce in the presence of oxygen, and obligate
anaerobes are those that grow only in the absence of free oxygen and are killed if exposed
to free oxygen. Facultative organisms are those that grow both in the presence of free
oxygen and in an oxygen-free atmosphere. Microaerophilic organisms are those that grow
only in reduced amounts of free oxygen.
Nutritionally, different bacteria require different foods that their particular
environment must provide. Autotrophic bacteria are self- nourishing and heterotrophic
bacteria are not self-sustaining. Moisture is indispensable for bacterial growth.
Morphologic characteristics are based on three distinct shapes or categories:
- Coccus (p1. cocci)-spherical, appearing singly, in pairs, chains, clusters, or packets.
- Bacillus (pl. bacilli)-rod-shaped, appearing singly, in chains, or in palisades.
- Spirillum (p1. spirilla)-spiral-shaped, corkscrew-shaped, or comma-shaped, appearing
singly only.
A colony is a cohesive mass composed of many millions of bacterial cells, growing on or
in a medium, such as blood agar, as a result of the multiplication and division of a
single cell. The size, color, shape, edge, topography, consistency, and odor of the colony
vary with each organism.
Three special structures assist in the classifica tion of bacteria. The capsule is a
gummy, gelatinous, or mucoid structure surrounding certain bacteria. The spore is an
inactive, resting, and resistant form produced within the organism, usually as a result of
unfavorable environmental conditions. The third and final special structure is the
flagellum, which is a hairlike structure that provides motility.
Toxins generally are waste products of metabolism in a bacterial cell. Some bacteria
produce toxins that attack red blood cells in a medium such as blood agar.
- Alpha hemolysin-produces partial hemolysis and changes the medium to a green color.
- Beta hemolysin-completely lyses the RBC, leaving a clear zone of hemolysis.
- Endotoxin (low potency)-comprises part of the cell wall and is released by autolysis of
the bacterial cell.
- Exotoxin (high potency)-is a soluble protein poison that is secreted by the living cell.
Gram's stain reactions can either be positive or negative. Gram-positive reactions will
stain dark blue-black. Gram-negative reactions will stain deep pink or reddish.
Common Bacteria
Bacteria are named by genus and species. The first word (capitalized) indicates the
genus; the second word (not capitalized) indicates the species, which is a subdivision of
the genus.
EXAMPLE:
GENUS |
SPECIES |
Neisseria |
gonorrhoeae |
Cocci
Gram-positive cocci (stain dark blue with Gram's stain)
- Streptococcus pneumoniae-causes pneumonia
- Streptococcus pyogenes (Beta Streptococci Group A)-causes strep throat
- Staphylococcus aureus-most common cause of boils and furuncles as well as osteomyelitis,
pneumonia, septicemia, endocarditis, and impetigo
Gram-negative cocci (stain dark pink with Gram's stain)
- Neisseria gonorrhoeae (gonococcus)-causes gonorrhea
- Neisseria meningitidis (meningococcus)-causes meningitis
Bacilli
Gram-positive bacilli
- Corynebacterium diphtheriae-causes diphtheria
- Clostridium (all are anaerobic and spore formers)
- C. perfringens (welchii)-causes gas gangrene
- C. septicum-causes gas gangrene
- C. tetani-causes tetanus or lockjaw
- C. botulinum-causes food poisoning (botulism)
Gram-negative bacilli
- Yersinia (Pasteurella) pestis-causes bubonic or pneumonic plague
- Brucella abortus-causes undulant fever (brucellosis)
- Bordetella pertussis-causes whooping cough
Intestinal (Enteric) Gram-Negative Bacilli
Salmonella
- S. typhi-causes typhoid fever
- S. paratyphi A & B-causes paratyphoid fever
- S. newport (S. enteritidis)-causes gastroenteritis
Shigella-all of these cause bacillary dysentery (shigellosis).
- S. dysenteriae (group A)
- S. flexneri (group B)
- S. boydii (group C)
- S. sonnei (group D)
Vibrio cholerae (comma)-causes cholera
Escherichia coli-normally a nonpathogenic organism in the intestine, but if it gets
into the abdominal cavity it can cause peritonitis. E. coli has also been known to cause
urinary tract infections and diarrhea.
Bacteriologic Methods
Smears
A smear can be made of almost all body discharges, lesions,
or sediments obtained by centrifugation of spinal fluid.
Preparation of Smear
Smear specimen on a glass slide previously cleaned with alcohol or acetone and
polished with lens paper. A thin and evenly spread smear is preferred for easier reading
of the smear and identification of various organisms. Emulsify specimen with saline if
thick.
Label the smear and circle material to be stained with a diamond point pen for easier
identification and location of the material after staining.
Let the smear air dry. Forced heat drying will distort bacterial cells and other
materials.
Fix the smear by passing it through a flame (smear side up) 3 to 4 times. DO NOT BURN
SMEAR.
Let slide cool and then stain.
Gram's Stain
The most common and useful staining procedure used in
bacteriologic work is that of Gram. It is most likely to yield valuable information and
should be done in all cases when staining is indicated. It is also used for the
examination of cultures to determine purity and for purposes of identification.
Hucker's Modification of Gram's Stain Solution
- Crystal violet/ammonium oxalate solution (primary stain):
Yeast contamination is
common and the stain must be filtered before use. Use only certified crystal violet.
Gentian violet and methyl violet are not recommended because they contain impurities.
Solution A: |
Crystal violet (certified) |
2 gm |
Ethyl alcohol (95 percent) |
20 ml |
Solution B: |
Ammonium oxalate |
0.8 gm |
Distilled water |
80 ml |
Mix solutions A and B, store for 24 hours, filter, and store at room temperature, in a
dark bottle, in a dark place, away from direct sunlight.
- Iodine solution (mordant):
Iodine crystals (USP) |
1 gm |
Potassium iodide |
2 gm |
Distilled water |
300 ml |
Grind iodine and potassium iodide in mortar. Dissolve potassium iodide in a flask in as
small amount of water as possible. Add iodine crystals to potassium iodide solution. When
dissolution is completed, add remainder of distilled water. Mix and let stand at room
temperature for 24 hours. Filter and store in a dark bottle, away from direct sunlight.
- Decolorizer:
Acetone |
1 volume |
Ethyl alcohol (95 percent) |
1 volume |
Mix 1 volume of acetone with I volume of ethyl alcohol and store in a tightly sealed
bottle.
- Safranine 0 counterstain:
Safranine 0 |
0.25 g |
Ethyl alcohol (95 percent) |
10 ml |
Distilled water |
90 ml |
Dissolve dye in ethyl alcohol, then add distilled water to dye solution and let stand
at room temperature for 24 hours. Filter and store away from direct sunlight.
Procedure
for Gram's Staining
After the smear has been dried, heat-fixed, and cooled off, proceed as follows:
- Place slide on staining rack and cover specimen with crystal violet. Let stand for 1
minute.
- Wash briefly in tap water and shake off excess.
- Cover specimen with iodine solution and let stand for 1 minute.
- Wash with water and shake off excess.
- Tilt slide at 45° angle and decolorize with the acetone-alcohol solution until the
purple color stops running. Wash immediately with water and shake off excess.
- Cover specimen with safranine and let stand for 30 seconds to 1 minute.
- Wash with water, shake off excess, and gently blot dry. The smear is now ready to be
read. (Use oil immersion lens.)
Principle of Gram's Stain
The crystal violet stain is the primary stain, which stains everything in the smear
blue. The Gram's iodine acts as a mordant that causes the crystal violet to penetrate and
adhere to the gram-positive organisms. The acetone-alcohol mixture acts as the decolorizer
that washes the stain away from everything in the smear except the gram-positive
organisms. The safranine is the counter-stain that stains everything in the smear that has
been decolorized: pus cells, mucus, gram-negative organisms. The gram-negative organisms
will stain a much deeper pink than the pus cells, and mucus will stain even lighter pink
than the pus cells.
Reading and Reporting Smears
Place a drop of oil in the slide and,
using the oil immersion objective of the microscope, read the smear. All body discharges
contain extraneous materials, such as pus cells and mucus. Of interest, however, are the
types of bacteria that may be present. The stained smear reveals only two things: the
morphology and the staining characteristics of the bacteria present. Positive
identification requires cultures and further studies.
The hospital corpsman reports only what he or she sees.
Example: "Smear shows numerous gram-negative bacilli." If two or more types
of bacteria are seen in a smear, the rule is to report them in order of predominance, for
example:
- Numerous gram-positive cocci in clusters
- Few gram-negative bacilli
Gram-positive organisms are easy to see because they stain a deep blue or blue-black.
Gram-negative organisms stain a deep pink, but since the background material is also pink,
minute and detailed inspection is necessary before reporting the results.
In the presence of gonorrhea the smear will reveal large numbers of pus cells with
varying numbers of intracellular and extracellular gram- negative, bean-shaped cocci in
pairs. Such a finding can be considered diagnostic. It is important to point out that only
a few of the thousands of pus cells on the slide may contain bacteria, and sometimes it
requires considerable search to find one.
Serology
Serology consists of procedures by which antigens and reacting
serum globulin antibodies may be measured qualitatively and quantitatively. Serologic
tests have been devised to detect either antigens present or antibodies produced in a
number of conditions. Most are based on agglutination reactions between an antigen and a
specific antibody.
Antigen is a substance that, when introduced into an individual who does not already
possess that substance, may stimulate the individual's cells to produce specific
antibodies that react to this substance in some detectable way. The four basic
characteristics of an antigen are it must be foreign to the body, it must possess a high
molecular weight, it must gain entrance into the body, and it must have a high specificity
to stimulate tissues to produce a defensive protein substance called antibody.
Antibodies are the specific defensive proteins produced when an antigen stimulates
individual cells. They are produced by the host in response to the presence of an antigen
and are capable of reacting with antigens in some detectable way.
The antigen-antibody reaction takes place as a result of a reaction between specific
antibodies in the plasma and antigen present on cell surfaces.
Rapid Plasma Reagin
(RPR)
Card Test for Syphilis
The RPR test is a sensitive, easily done screening test for syphilis. It is performed
on unheated plasma or serum. Everything needed for the test is in a kit that is available
commercially. This is very useful aboard ship and at small stations not equipped to do the
VDRL.
Principle of the Test
The RPR test is a nontreponemal testing procedure for the serologic detection of
syphilis. The RPR card antigen suspension is a carbon- particle cardiolipin antigen that
detects reagin, an antibodylike substance present in the sera from syphilitic persons and
occasionally in sera of persons with other acute or chronic conditions. When a specimen
contains antibody, flocculation occurs with a coagglutination of the carbon particles of
the RPR card antigen, which appear as black clumps against the white background of the
plastic-coated card. Nonreactive specimens appear to have an even light-gray color.
Reagents
- RPR Card Test Antigen
- The antigen consists of cardiolipin, lecithin, cholesterol, EDTA, Na2HPO4, KH2PO4,
charcoal, choline chloride (10 percent), distilled water, and the preservative thimerosal
(0.1 percent) (supplied in kit).
- Store unopened vials at 40C. Stable to expiration date.
- Store "in-use" antigen suspension in dispensing bottle at 4 degrees C. Stable
for about 3 months, or until expiration date if it occurs sooner.
- Record antigen lot number and expiration date on dispensing bottle.
- RPR Card Test Control Cards
- The card consists of three labeled test areas containing lyophilized specimens with
designated patterns of reactivity: Reactive, Reactive-Minimal- to-Moderate, and
Non-reactive.
- Store unopened foil-sealed envelopes at 4 degrees C. Stable to expiration date.
- Not supplied with the kit and must be purchased separately.
Equipment
Needle
- Supplied in kit
- Adjusted to deliver 60 drops, plus or minus 2 drops, per milliliter of antigen.
Dispensing Bottle
- Supplied in kit
- Used to store in-use antigen
Rotator-Adjusted to 100 r.p.m.
Dispenstir
- Supplied in kit
- Manufactured to dispense 0.05 ml of serum
Diagnostic Cards
- Supplied in kit
- Plastic-coated cards, with 10 rings, for testing patient specimens.
Preliminary Preparation for Testing
- Remove antigen suspension vial and one control card envelope from the refrigerator.
Allow to adjust to room temperature.
- Resuspend contents of vial by vigorously shaking the antigen vial.
- Snap the neck of the vial.
- Attach the needle (provided in the kit) to a 1 milliliter tuberculin syringe. Slowly
draw up into the syringe approximately 1 milliliter of the antigen suspension from the
vial.
- Hold the syringe perpendicular to the surface, and count the number of drops dispensed
from a 0.5 ml volume. Allow the drops to fall into the antigen vial. The needle is
accurate if 30 drops, plus or minus 1 drop, are dispensed from the 0.5 ml volume.
- Slowly expel the remainder of antigens in the syringe back into the antigen vial.
- Remove the needle from the syringe; place the needle on the tapered fitting of the
plastic dispensing bottle (provided in kit).
- Slowly withdraw all contents of the antigen vial by collapsing the dispensing bottle and
using it as a suction device.
- Allow the rotator to warm up for 5 to 10 minutes; adjust to 100 r.p.m.
Test Procedure
- Open foil package and remove control card.
- Reconstitute each control card circle with 0.5 ml of distilled water by use of a
dispenstir.
- Using the broad end of the dispenstir, mix until the dehydrated control specimen is
dissolved. Spread specimen over entire area of circle. Use a separate dispenstir for each
circle.
- To draw the patient's sample, hold the dispenstir between the thumb and forefinger near
stirring or sealed end and squeeze; do not release pressure until the open end is below
the surface of the specimen. Release finger pressure to draw up the sample.
- Hold the dispenstir in a vertical position, directly over the card test area to which
the specimen is to be delivered; squeeze dispenstir, allowing 1 drop to fall onto the test
area.
- Invert the dispenstir, and, with the sealed end, spread specimen within the confines of
the circle. Discard the dispenstir.
- Continue the above steps until one or two test cards are filled with patient's samples.
- Gently shake the antigen dispensing bottle before use. Hold in the vertical position and
dispense several drops into the dispensing bottle cap to ensure that the needle passage is
clear. Allow 1 "free-falling" drop to fall onto each test area. Do not stir;
mixing of antigen suspension and specimen is accomplished during rotation.
- Put card(s) on rotator and cover with humidifying cover.
- Rotate for 8 minutes at 100 r.p.m. Following rotation, to help differentiate Nonreactive
from Reactive results, a brief rotating and tilting of card by hand (3 to 4 to-and-fro
motions) must be made.
- Then immediately read Card macroscopically in the "wet" state and under the
high-intensity lamp.
- The Reactive control should show characteristic strong clumping; the Nonreactive control
should show smooth, grayish appearance of unclumped particles. The Reactive Minimal-to-
Moderate control should show minimal-to- moderate clumping. The patients' tests should be
compared to the controls for correct interpretations.
- Report test as:
- Reactive if specimen shows agglutination or flocculation.
- Nonreactive if specimen shows no agglutination at the end of 8 minutes rotation.
- If the RPR test is reactive, an FTA-ABS (Flourescent Treponemal Antibody Absorption
Test) must be run on the specimen.
Monosticon Slide Test for
Infectious Mononucleosis The main reason for including this test is that
mononucleosis imitates many diseases so well that diagnosis is confirmed only by selective
serologic testing.
Principle of the Test
- Absorption of serum with a suspension of a guinea pig or horse kidney antigen removes
antisheep agglutinins in the serum of patients with serum diseases and various infectious
diseases.
- In some serum of patients with infectious mononucleosis, a substantial part of the
antibodies remains after absorption.
- Absorption with a suspension of beef cells removes the antisheep agglutinins in
infectious mononucleosis, but leaves them in other infectious diseases.
Rapid slide tests for infectious mononucleosis are based on these principles.
Suspensions of guinea pig kidney and beef erythrocyte stomata result in satisfactory
instant absorption of antibodies and clear differentiation between infectious
mononucleosis and noninfectious mononucleosis sera. Infectious mononucleosis antibodies
may be demonstrated as early as the fourth day of illness and practically always by the
twenty-first day. Positive results may continue for several months.
Procedure
- On a clean slide (supplied with kit) place 1 drop of guinea pig antigen, reagent I, into
box number 1.
- Place 1 drop of the beef erythrocyte stomata, reagent II, into box number 2.
- Add 1 drop of test serum on plasma to both boxes. Mix each with separate sticks.
- Add 1 drop of horse erythrocyte antigen (supplied with kit) to both boxes. Mix each with
separate disposable sticks.
- Rock slide back and forth for 2 minutes so that liquid flows slowly over the entire area
of the boxes.
- Read results after 2 minutes.
- Agglutination in box 1 is positive for infectious mononucleosis.
- Agglutination in box 2 is positive for noninfectious mononucleosis.
- No agglutination in either box is negative for mononucleosis.
A positive control is included in each kit for the purpose of checking the
effectiveness of the reagents.
Fungus (Pl. Fungi)
Fungi are heterotrophic, chlorophyll-free,
thallophyllic organisms. They reproduce by spores, which germinate into long filaments
called hyphae. As the hyphae continue to grow and branch, they develop into a mat of
growth called the mycelium (pl. mycelia). From the mycelium, spores are produced in
characteristic arrangements. These spores, when dispersed to new substances, germinate and
form new growths. Reproduction is often asexual, usually by budding, as in yeast, but
certain fungi have sexual reproduction.
Common superficial infections of the skin caused by fungi are athlete's foot and
ringworm of the scalp.
Potassium
Hydroxide (KOH) Preparation for Identification of Fungi
Fungi are seen in clustered round buds with thick walls accompanied by fragments of
mycelia. Scrapings from the affected area of the skin are mounted in 10 percent KOH for
positive laboratory diagnosis.
Demonstration of the fungi in infected tissue can be accomplished by the following
method:
- Place skin, hair, or nail scrapings from the affected area on a slide and add a drop of
10 percent KOH. Dissolve 10 g of KOH in 100 ml of distilled water.
- Place a coverslip on the preparation.
- Warm the preparation gently over a flame, being careful not to boil it, and allow it to
stand until clear. Do not allow the preparation to dry out.
- Read preparation, using a high-power objective with subdued light.
- Fungi in the skin and nails appear as refractile fragments of hyphae.
- In the hair, fungi appear as dense clouds around the hair stub or as linear rows inside
the hair shaft.
Blood Grouping
Blood transfusion, the term used for the process of transferring blood from one person
to another, is often a lifesaving remedy, especially in cases of severe hemorrhage,
anemia, and infection.
In 1900 Landsteiner discovered the first blood group system that initially comprised
groups A, B, and O. Later the AB system was added.
Agglutination
The work showing that blood can be classified into these
four groups was done by random cross matching of the bloods of a large number of people.
Two specific antigens (also called agglutinogens) were found on the red cells. These were
called A and B. One group of red cells contained no A or B antigen and was called O. A
fourth group contained both A and B antigens and was called AB. Antibodies (agglutinins)
were found in the serum of blood. These were called anti-A and anti-B antibodies. A person
of group A blood (A antigen) has anti-B antibodies (agglutinins) in the serum. A group B
individual has anti-A antibodies; a group O individual has both anti-A and anti-B
antibodies; and group AB individuals have neither antibody in the serum. With the
exception of certain patients with autoimmune diseases, individuals do not have antibodies
against their own blood type.
Landsteiner's rule states that when an antigen is on a red blood cell, the
corresponding antibody is never present simultaneously. Instead, the reciprocal red cell
antigen is present in the plasma or serum. For example, if an individual has blood cells
of group A, anti-B antibodies are always present in the serum but never anti-A.
Blood grouping is accomplished by comparing the effects of agglutination by the
antibodies on the corresponding antigens within the red cells.
To determine the group to which blood belongs, it is necessary to mix separately a
suspension of its red cells with serum of a known group A and a group B that contains
agglutinin B and agglutinin A, respectively. The resulting agglutination or absence of
agglutination determines the group to which it belongs and is a necessary procedure with
the blood of both the donor and the recipient. Only compatible blood is selected for
transfusion. One of the four combinations of reactions shown in the table 7-1 will result.
Table 7-1.-Agglutination Reactions of the Red Cells of the Four Blood Groups
International Blood Group |
Anti-A |
Anti-B |
O |
- |
- |
A |
+ |
- |
B |
- |
+ |
AB |
+ |
+ |
Rh Factors
The most important Rh factor is factor D. Approximately 85
percent of the population is D positive (also called Rh positive), and 15 percent is D
negative (also called Rh negative). Agglutinin for Rh + does not normally occur in the
blood. Consequently, Rh + corpuscles do not produce reactions in first transfusions.
However, the agglutinogen, when present in large amounts in the blood of recipients, may
produce reactions upon transfusion with Rh + corpuscles. Consequently, it is mandatory to
select compatible donors whose corpuscles are Rh - for transfusion of Rh - individuals.
This is especially important in those who have had previous transfusions (especially with
Rh + corpuscles).
Technique for Blood Grouping and
Typing
Determination of the A and B agglutinogen is called grouping, while determination of
the Rh agglutination is called typing (fig 7-1.) Color-coded
Anti-A (blue), and anti-B (yellow), are available through the Navy Supply System.
Blood grouping for the A-B-O system is performed at room temperature. A blood specimen
is drawn and allowed to clot. The erythrocytes are resuspended in the serum by mechanical
agitation, and single drops are placed on a clean glass slide by a dropper. Colored
specific sera are added, and each drop of blood and antiserum are individually mixed with
a clean applicator stick. The preparation is observed for agglutination. If agglutination
takes place, the red cells gather in clumps. If there is no agglutination, the red cells
will be evenly distributed over the field (see fig. 7-1).
The rouleaux formation is another phenomenon that causes trouble in blood typing. It is
caused by sera with high globulin content and appears as "red cells stacked up like a
pile of coins." Rouleaux formation can easily be confused with true agglutination.
CAUTION: Droppers must be used only in their respective sera and cell suspensions to
prevent cross-contamination. Applicator sticks used for mixing anti-A and the cell
suspension must not be used for mixing anti-B and the cell suspension, and vice versa.
Responsibilities in the
Clinical Laboratory
As a hospital corpsman, you
need to know how to perform the tests discussed in this chapter, especially when you are
on duty independent of a medical officer. Although you are not expected to diagnose or
treat a patient based on the test findings, you must be able to convey a clear clinical
picture to your supporting medical officer to effect prompt, efficient, and professional
patient care.
It is very important that the patient, as well as the specimens received, be promptly
and properly identified to prevent errors and to minimize future embarrassment and medical
complications.
Another important facet of clinical laboratory is the proper use of laboratory forms.
Use separate forms for each patient and each type of test. The forms must be filled out
completely, accurately, and legibly to ensure expeditious disposition of completed
reports. In addition, they must be properly filed and recorded.
In the laboratory you constantly will be dealing with the numerous laboratory forms
associated with the tests being performed. These forms when used properly will minimize
confusion and reduce chances for errors. For a complete listing of these forms and their
purposes, refer to MANMED, chapter 23.
Ethics in the Laboratory
You are expected to treat all laboratory
tests and their results as a confidential matter. Interpretation of the results must be
left to the attending physician. Refrain from discussing laboratory results with the
patient. It is your ultimate responsibility to safeguard laboratory results from
unauthorized access by persons not directly involved. Remember that knowledge of the tests
and their results are accessible only to the patient, the attending physician, and you-the
performing technician.
References:
Technical Manual (AABB), 8th Edition
Lennette, Halows, Hansler, Truant, Manual of Clinical Microbiology, 3rd Edition
RPR Card Test & Control Cards, Hynson, Wescott & Dunning
Monosticon Dri Dot, Organon Diagnostics
Naval Education and Training Command: Hospital Corpsman 1 & C: August 1986
Approved for public release; Distribution is unlimited.
The listing of any non-Federal product in this CD is not an
endorsement of the product itself, but simply an acknowledgement of the source.
Operational Medicine 2001
Health Care in Military Settings
Bureau of Medicine and
Surgery
Department of the Navy
2300 E Street NW
Washington, D.C
20372-5300 |
Operational
Medicine
Health Care in Military Settings
CAPT Michael John Hughey, MC, USNR
NAVMED P-5139
January 1, 2001 |
United States Special Operations Command
7701 Tampa Point Blvd.
MacDill AFB, Florida
33621-5323 |
*This web version is provided by
The Brookside Associates Medical Education
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The presence of any advertising on these pages does not constitute an
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