Increased in vitro fitness of multi- and extensively drug-resistant F15/LAM4/KZN strains of Mycobacterium tuberculosis

摘要: The role of fitness in transmission drug-resistant strains has been explored previous studies; but not established for F15/LAM4/KZN strains, which were responsible the extensively tuberculosis (XDR-TB) outbreak Tugela Ferry, South Africa. biological 15 clinical representing F15/LAM4/KZN, Beijing, F11 and F28 families was determined by growth, viability competition assays correlated with DNA sequencing eight genes associated drug resistance putative compensatory mechanisms. Similar growth rates observed among susceptible, multidrug-resistant (MDR) XDR KZN genotypes. In contrast, Beijing MDR demonstrated significantly reduced fitness. Resistant exhibited heterogeneous profiles different susceptible suggesting strain dependence. addition, co-culture consistently higher than independent 13/14 pairs. All 14 retained viability, at a low CFU/mL, when paired strains. persistence such resistant could consequently support acquisition additional drug-resistance-conferring mutations and/or evolution Frequently occurring detected whereas, harboured less common katG mutation had no mutation. Contrary to successful particularly during outbreak, may be attributed presence little or costs. Amplified suggestive vivo trans-complementation.