Detection of gyrA QRDR mutations using the qPCRgyrALp assay.
Melting curves and peaks obtained with the qPCRgyrALp assay are shown for the L. pneumophila Paris strain (Martínez, 2008), respiratory samples from patients #1 to #4 (Skippington and Ragan, 2011), the L. pneumophila Lorraine strain (Pendleton et al., 2013), the L. pneumophila Philadelphia strain (Rolain and Raoult, 2005), the L. pneumophila Lens strain (Rouli et al., 2012), and the L. pneumophila Paris mutant strains LPPI1 and LPPI4 harboring one (Maurin et al., 2001), and two (Binet and Maurelli, 2005) gyrA mutations, respectively (appendix p 5). The units of the y axes are expressed as fluorescence levels derived through time. Melting peaks of 59.34 ± 0.41 °C and 56.35 ± 0.42 °C are diagnostic of reference and mutant alleles of the gyrA QRDR, respectively.