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Analysis of
Legionella
in water by the PCR method
The
Legionella
genus contains over 50 species, which at least 24 are
associated with infections in human being. These bacteria are ubiquitous in
the aquatic environment and are able tomultiply intracellular in organisms in
freshwater, they are found in many types of water sources and their growth is
especially favored in man-made hot water systems, including cooling towers
and air conditioning-heating-ventilation systems, hot tubs and spas.
The best characterized and species type of the genus
Legionella
pneumophila
, the causative agent of Legionnaires’ disease, a severe
form of acute pneumonia, which if not treated early, may lead to death
(Newton
et al
., 2010). The bacterium
L. pneumophila
belong to the class
Gammaproteobacteria, order Legionellales, family Legionellaceae.
Legionella
sp. is closely related to nosocomial infections, therefore the detection and
monitoring is extremely crucial for the prevention of infectious processes.
This bacterium is a Gram-negative bacillus that in the environment may be
associated with
Acanthamoeba polyphaga
(Amoebozoa: Acanthamoebidae).
A good prognosis depends in part on a specific early treatment; also, the
rapid identification of the causative agent is of great importance.The culture is
essential to identify the strains of bacteria during outbreaks. However, based
on cultivationmethods it shows a long incubation period (10 days), since this
bacterium is a fastidious growth organism, thus hindering its early diagnosis.
The strategy of risk management of
Legionella
spp. requires faster methods.
Moreover, under certain conditions (nutrient poor environments or osmotic
stress, the presence of biocides or toxic metal ions, etc.), some opportunistic
pathogens, such as
L. pneumophila
can remain viable but not in culturable
state, which are not detectable by standard methods of cultivation, but, as it
still remains viable, their infective capacity remains, and thus its virulence.
