The use of in vitro assays to query MIC values may be a limitation, however, macrolide resistance in the pneumococcus, caused by either erm(B) or mef(E)/mel-containing isolates, has been linked to treatment failures for lower respiratory tract infections and bacteremia (Klugman, 2002; Lonks et al., 2002; Schentag et al., 2007; Zähner et al., 2010). This evidence concerns the gene ETV5 and bacterial infectious disease with sepsis.