environmental and primate assay data sheet
Shigella
and enteroinvasive
E. coli
Test codes:
B0008
-
Qualitative
detection of Shigella
and enteroinvasive E. coli
bacteria, by polymerase chain reaction. Assay
detects but does not
differentiate
S. boydii, S. dysenteriae, S.
flexneri, S. sonnei, and enteroinvasive
E. coli strains
including EIEC 41, EIEC 42, EIEC 120 and EIEC 121.
B0054
-
Ultrasensitive
qualitative detection of
Shigella bacteria only, by real time polymerase
chain reaction. This assay
detects but does not differentiate most
Shigella strains; it
does not detect E.
coli.
Test B0054 is
included in
P0041
- waterborne pathogens screening panel
B0055
- Quantitative assay for
Shigella bacteria by real time polymerase chain reaction.
This assay detects and
quantifies
Shigella DNA present in a sample as a percentage of
the total DNA present in the sample. The assay does not
differentiate Shigella
strains and does not detect
E. coli.
Shigella
bacteria are gram negative, non-spore forming bacilli.
S. flexneri (types
2, 4, 6), S. sonnei
and S. dysenteriae
are the most common organisms causing problems in primates.
Humans are considered their main reservoir.
Shigella-induced
dysentery is often mistaken for EIEC (enteroinvasive
E. coli). Five
recognized classes of enterovirulent
E. coli
(collectively referred to as the EEC group) cause
gastroenteritis in humans. Although
E. coli is
considered part of the normal intestinal flora of humans and
other primates, a minority of
E. coli strains are
capable of causing illness in human and primates by several
different mechanisms. Among these are the enteroinvasive (EIEC)
strains.
Both
Shigella and EIEC
are transmitted through the fecal-oral route, through
contaminated food or water or by direct contact, aerosol, or
mechanical vectors such as flies. The organisms are shed from
both clinically ill and asymptomatic humans and primates. Even
minimal contact is adequate for transmission.
Infection of
primates by these bacteria usually results in a subclinical
carrier state, but disease may then be induced by stress. Signs
include watery to bloody diarrhea, weakness, and edema of the
face and neck. Rectal prolapse is common. High mortality can
result from Shigellosis in primates. Recovered animals are often
carriers and can act as a reservoir of infection.
Fecal or
blood culture with selective media is sometimes used to identify
Shigella and enteroinvasive
E. coli. However, microbiological culture is slow and not
very sensitive. Molecular detection of these bacteria is highly
sensitive and specific, and is also highly tolerant of
suboptimal specimen shipping and handling conditions that would
invalidate other testing methods.
Utilities:
-
Help confirm the disease causing agent
-
Shorten the time required to confirm a clinical
diagnosis of Shigella
or EIEC infection
-
Help ensure that colonies are free of these bacteria
-
Early prevention of spread of these bacteria among a
colony
-
Minimize personnel exposure to these bacteria
-
Safety monitoring of biological products and vaccines
that derive from primates
Specimen requirements:
Preferred
specimens
- Rectal swab, or 0.2 ml feces or bacterial culture.
Less preferred specimen
- 0.2 ml whole blood in EDTA (purple top) tube.
Note: Fecal
and swab samples are not recommended for assay B0055, as solid
samples generally cannot be accurately
quantitated in this assay. Liquid samples such as culture
or blood are recommended for accurate quantitation.
Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.
For all
specimen types, if there will be a delay in shipping, or during
very warm weather, refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping requirements are
specified. Frozen specimens should be shipped so as to remain
frozen in transit. See shipping
instructions for more information.
Turnaround time:
2 business days
Methodologies:
B0008 -
Qualitative PCR
B0054
- Qualitative real time PCR
B0055 -
Quantitative
real time PCR
Normal range:
Nondetected