environmental, wildlife and zoo assay data sheet
Legionella pneumophila
Test code:
B0085
-
Ultrasensitive qualitative detection of
Legionella pneumophila
by real time PCR.
Test B0085 is
included in
P0041
- waterborne pathogens screening panel
Legionnaires' disease is caused by Legionella bacteria, particularly
Legionella pneumophila. Legionella bacteria are
found naturally in the environment, usually in water, growing
best in warm water. They are often found in hot tubs, cooling
towers, hot water tanks, large plumbing systems and decorative
fountains.
L. pneumophila
is a gram-negative, non-encapsulated, aerobic coccobacillus with a single,
polar flagellum. It has a colony morphology that is gray-white
with a textured, cut-glass appearance. It requires a supply of
cysteine and iron to survive. It is a facultative intracellular
bacterium that lives inside amoebae in the environment. This
protects the bacterium from water chlorination and other
environmental stresses.
People infected with Legionella can
have symptoms similar to those of other forms of pneumonia, so
clinical diagnosis can be difficult. Symptoms may include
cough, shortness of
breath, high fever, muscle
aches and headaches.
These
symptoms usually begin 2 to 14 days after exposure to the
bacteria.
In
USA, the prevalence of infections with L. pneumophila
is approximately 30 people per 100,000 residents per year. The
infection rate peaks in the summer months. In endemic regions
about 4-5% of pneumonia cases are caused by L. pneumophila.
Diagnosis of the disease has been done by bacterial culture or
urine antigen tests. Legionella stains poorly with gram
stain, but stains positive with silver. The growth of these
bacteria requires specific culture medium, such as charcoal
yeast extract with iron and cysteine. Thus, culture is not a
sensitive method to detect these bacteria. The urine antigen
test also is also not very sensitive
However, studies have shown
that combining the urine antigen test with molecular detection
by polymerase chain reaction (PCR) can significantly increase
the specificity and sensitivity of the diagnosis (Koide et al.,
2006).
Utilities:
-
Help confirm the disease causing agent
-
Shorten the time required to confirm a clinical
diagnosis of Legionella
-
Help ensure Legionella-free facilities
-
Early prevention of spread of Legionella in
a facility or geographic area
-
Minimize human exposure to this bacterium
-
Safety monitoring of biological products that derive
from susceptible animals
-
Environmental monitoring of water supplies,
equipment and facilities
References:
Koide, M., Higa, F., Tateyama, M., Nakasone, I., Yamane, N. and
Fujita, J. (2006) Detection of Legionella species in
clinical samples: Comparison of polymerase chain reaction and
urinary antigen detection kits. Infection 34:264-268.
Specimen requirements:
0.2 ml whole blood in EDTA (purple top) tube, or nasal swab, or environmental swab, or 0.2 ml
serum, culture, sputum, tissue, bronchoalveolar lavage, or water
sample.
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
Methodology:
Qualitative real time PCR
Normal range:
Nondetected
|