design: The strains were isolated on MH agar plates and a single colony was used to start an overnight growth in 15 mL MH broth at 37C under vigorous shaking. DNA was extracted from 1 mL cultures using the MasterPure Complete DNA and RNA Purification kit (LGC Biosearch technologies) by following the manufacturer's recommendations with the following modifications: i) 05 L of proteinase K was used instead of 1 L, ii) 15 L of RNAse A was used instead of 1 L, iii) incubation with RNAse A was performed for 90' instead of 30' and included mixing of the samples by inverting them 10 times every 15'. Extracted DNA was quantified using Qubit 20 (Invitrogen) and the dsDNA broad range assay kit (Invitrogen)