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For these reasons,molecularmethods andDNAamplification techniques
may be useful strategy for the detection and quantification of
Legionella
isolated from clinical and environmental samples. Among the rapid
diagnosis methods of
Legionella
, DNA amplification by PCR (
Polymerase
Chain Reaction
) has been used and optimized by several research groups due
to its effectiveness in biological and environmental samples with different
characteristics. To be useful for clinical diagnosis, the PCR detection should
fulfill certain requirements, such as the detection of the pathogen in samples
containing low numbers of bacteria, it must provide easy and quick results
and avoid, where possible, false negative due to the inhibition of amplification.
The contaminant source is always water, whether actual water or droplets
suspended in air. Investigations of these contamination spots are the main
factor to know pathogen. The recovery and reuse of water is increasingly
common, however there are few studies about the microbial diversity present
in this type of water, since the recovered water is examined only for the
presence of coliforms. Many microorganisms (eg,
Campylobacter jejuni
,
Yersinia enterocolytica
, nontuberculous mycobacteria,
Pseudomonas
sp and
enteric viral pathogens, such as hepatitis A, rotavirus and the Norwalk virus;
and pathogenic protozoa, such as
Giardia lamblia
,
Cryptosporidium
, and
amoeba
Acanthamoeba
spp and motile
Negleria
spp.) including isolates of
Legionella
are known to be more resistant to chlorine than coliforms. Studies
suggest that
Legionella
sp. after exposure to high levels of residual chlorine
typically found in this type of water source may become non-culturable in
the laboratory, since it was not possible the isolation of
Legionella
spp. in
culture of recovery water, being only possible by molecular detection.
A system for sensitive and specific detection of
L. pneumophila
in water
was developed by Starnbach
et al
. (1989). The system is based on the cleavage
