Serotypes and genotypes of Streptococcus pneumoniae causing pneumonia and acute exacerbations in patients with chronic obstructive pulmonary disease

Results: Pneumococci isolated from AECOPD episodes were significantly more resistant to co-trimoxazole and chloramphenicol than those isolated from pneumonia episodes (39.0% versus 29.7% and 13.8% versus 8.2%, respectively, P,0.05). Comparing serotypes of isolates causing bacteraemic pneumonia, non-bacteraemic pneumonia and AECOPD, serotypes 4, 5 and 8 were associated with bacteraemic pneumonia (P,0.05), serotypes 1 and 3 were associated with bacteraemic and non-bacteraemic pneumonia (P,0.05) and serotypes 16F and 11A and non-typeable pneumococci were associated with AECOPD episodes (P,0.05). The genotypes related to serotypes 3 (Netherlands 3 -ST180 and ST260 3 ), 1 (Sweden 1 -ST306), 5 (Colombia 5 -ST289) and 8 (Netherlands 8 -ST53) were isolated more frequently in pneumonia episodes (P,0.05), whereas genotype ST30 16F (serotype 16F) was more frequently recovered from AECOPD episodes. Conclusions: In our experience, serotype 3 pneumococci (Netherlands 3 -ST180 and ST260 3 genotypes) commonly cause pneumonia and acute exacerbations in COPD patients. Pneumococci of serotypes 1 (Sweden 1 -ST306), 4 (ST247 4 ), 5 (Colombia 5 -ST289) and 8 (Netherlands 8 -ST53) were more often associated with pneumonia. Non-typeable pneumococci may play an important role in acute exacerbations.