Differentiation of pathogenic and non-pathogenic leptospires by means of the polymerase chain reaction

Abstract

A polymerase chain reaction was carried out to detect pathogenic leptospires isolated from animals and humans in Argentina. A double set of primers (G1/G2, B64-I/B64-II), described before, were used to amplify by PCR a DNA fragment from serogroups belonging to Leptospira interrogans but did not allow to detect saprophytic strains isolated from soil and water (L. biflexa). This fact represents an advantage since it makes possible the differentiation of pathogenic from non-pathogenic leptospires in cultures. The sensitivity of this assay has been determined, allowing to detect just only 10 leptospires in the reaction tube. Those sets of primers generated either a 285 bp or 360 bp fragment, depending on the pathogenic strain.

Leptospirosis

“…PCR has been used to distinguish pathogenic from nonpathogenic serovars (407,444,639). Recently, a fluorescentprobe 5Ј exonuclease PCR assay was described for the rapid detection of pathogenic leptospires (637).…”

Recommendations for the detection of Leptospira in urine by PCR

“…Gravekamp et al 9 designed two pairs of primers for the specific amplification of DNA of pathogenic leptospires. With some modifications, this method was applied in the analysis of several strains isolated in Argentina, from water, soil and human patients 15 .…”

Preliminary Study on Differentiation of Leptospira Grippotyphosa and Leptospira Sejroe from Other Common Pathogenic Leptospiral Serovars in Canine Urine by Polymerase Chain Reaction Assay

“…Similar to this study, another group reported that a 360-bp product was amplified from serovar L. grippotyphosa and L. cynopteri (both belong to species of L. kirschneri) with the G1/G2 and B64-I/B64-II multiplex PCR method. 6 However, the error was not pointed out and neither was the size nor the sequence of the fragment confirmed by sequencing. (6), L. autumnalis (7), and L. sejroe (8).…”

“…6 However, the error was not pointed out and neither was the size nor the sequence of the fragment confirmed by sequencing. (6), L. autumnalis (7), and L. sejroe (8). Lane 9: reagent control.…”