ABSTRACT
We present a novel denaturing gradient gel electrophoresis (DGGE) method which characterizes multiclonal communities of Staphylococcus aureus. The spa PCR-based DGGE method simultaneously separates strains that differ in only one base, thereby revealing multiclonal colonization and infections.
Subject(s)
Coinfection/microbiology , Denaturing Gradient Gel Electrophoresis/methods , Molecular Typing/methods , Staphylococcal Infections/microbiology , Staphylococcal Protein A/genetics , Staphylococcus aureus/classification , Staphylococcus aureus/genetics , DNA, Bacterial/genetics , Humans , Polymerase Chain Reaction/methods , Staphylococcus aureus/isolation & purificationABSTRACT
For an infecting bacterium the human body provides several potential ecological niches with both internally (e.g. host immunity) and externally (e.g. antibiotic use) imposed growth restrictions that are expected to drive adaptive evolution in the bacterium, including the development of antibiotic resistance. To determine the extent and pattern of heterogeneity generated in a bacterial population during long-term antibiotic treatment, we examined in a monoclonal Mycobacterium tuberculosis infection antibiotic resistant mutants isolated from one patient during a 9-years period. There was a progressive accumulation of resistance mutations in the infecting clone. Furthermore, apparent clonal sweeps as well as co-existence of different resistant mutants were observed during this time, demonstrating that during treatment there is a high degree of dynamics in the bacterial population. These findings have important implications for diagnostics and treatment of drug resistant tuberculosis infections.
