Objective: To compare the value of leptospiral DNA extraction procedures from clinical samples
for the early diagnosis of leptospirosis.
Methods: Three DNA extraction procedures were applied for microbiological analysis, results of
QIAmp DNA mini kit (QIAGEN, Germany), CLART HPV kit (GENOMICA, Spain) and Chelex-100 assay
were compared concerning extraction efficiency, DNA purity and DNA suitability for amplification
by specific polymerase chain reaction for pathogenic leptospires from blood, plasma and serum
artificially infected.
Results: The comparison of extraction methods highlighted the efficiency of Chelex-100 and
QIAmp DNA mini kit. Chelex-100 achieved the isolation of the highest concentration of leptospiral
DNA from the culture and the spiked samples, with acceptable purities and without inhibitors to
PCR.
Conclusions: Chelex-100 assay is a rapid and effective approach for DNA isolation in clinical
samples having pathogenic leptospires and it could be useful in the early diagnosis of
leptospirosis.