Serotype incidence and antibiotic susceptibility of Streptococcus pneumoniae causing invasive disease in Scotland, 1999-2002

Pneumococcal disease remains an important cause of invasive and non-invasive disease in Scotland and elsewhere. The Scottish Meningococcus and Pneumococcus Reference Laboratory receives isolates of Streptococcus pneumoniae from diagnostic laboratories around Scotland. Here, the serogroups/types and antibiotic-susceptibility patterns of invasive isolates received between 1999 and 2002 are described. There were a total of 1741 invasive isolates received, the most common serogroups/types being 14 (19.8%), 9 (10.2%), 6 (8.3%), 19 (7.9%), 23 (7.9%), 4 (6.5%), 8 (6.4%), 3 (5.7%), 1 (3.8%), 7 (3.8%) and 18 (3.4%). Importantly, serotypes 7 and 8 are not represented in the 7-, 9- and 11-valent pneumococcal conjugate polysaccharicle vaccines. There were 67 (3.8%) isolates considered penicillin non-susceptible, although no penicillin resistance (MIC >= 0.002 mg ml(-1)) was recorded. One hundred and ninety-four (11.1%) isolates, predominantly of serotype 14, were resistant to erythromycin, and 12 (0.7%) were resistant to ciprofloxacin. This information provides an important dataset that will prove essential prior to and during the implementation of pneumococcal conjugate vaccines in the UK.