Summary

The antimicrobial susceptibility of all 492 viable invasive isolates of S. pneumoniae referred to ESR in 2005 was tested. 17.1% (84) were categorised as penicillin nonsusceptible (MIC ≥0.12 mg/L): 7.1% (35) as resistant (MIC ≥2 mg/L) and 10.0% (49) as intermediate (MIC 0.12-1 mg/L). Over the last decade there has been considerable variation in the prevalence of penicillin resistance, with a significant increase between 1995 and 1998-9, a decrease between 1999 and 2002 and then a further increase (Figure 1). Penicillin nonsusceptibility increased between 1995 and 1999, but there has been no significant change since then.