FIG. 6.—

Alignment of the PenA protein sequences from the 7 sequenced strains. The suggested topology based on the concatenated 1,072 genes (fig. 1) is shown along with the alignment. Alterations in the nine amino acid sites (in boxes) have been shown to be associated with intermediate resistance to penicillins (Thulin et al. 2006; Taha et al. 2007). Among these nine amino acid sites, five alterations (F504L, A510V, I515V, H541N, and I566V; shown in red boxes) were found in all examined intermediate resistance isolates in (Taha et al. 2007; Vázquez et al. 2007; du Plessis et al. 2008).