Abstract
Background & Objectives: Antibiotic resistance of Streptococcus pneumoniae, especially against β-lactam antibiotics, is a global concern. We aimed to analyze ten-year trend in resistance genotype of respiratory isolates of S. pneumoniae, and to clarify whether resistance genotypes were correlated with phenotypic susceptibility, pathogenicity and host clinical background.
Methods: Respiratory isolates of S. pneumoniae from 2003 to 2012 were analyzed with polymerase chain reaction for the presence of β-lactam resistance gene mutation on pbp1a, pbp2x, and pbp2b. Sixty-eight strains isolated from different patients in 2012 were particularly analyzed for the association between genotypes and clinical data.
Results: Ten-year trend analysis showed the recent increase of gPRSP which has all three β-lactam resistance genes (21.7% to 35.3% in three years) and the steady share of gPSSP without any β-lactam resistance genes (13.2% in 2012). This resistance trend in genotypes was more prominent than resistance phenotypes derived from drug susceptibility test. The probability of being causative pathogen did not differ in gPSSP (56%), gPISP (54%), and gPRSP (54%). There was no significant difference in the ratio of patients who presented with respiratory failure in respiratory infection caused by gPSSP, gPISP, or gPRSP. Host clinical characteristics including age and gender were not different among resistance genotypes.
Conclusions: Genotype resistance in respiratory isolates of S. pneumoniae insidiously prevailed more than phenotypic antibiotic resistance. There was no difference in pathogenicity or clinical background between gPSSP, gPISP, and gPRSP.
- © 2014 ERS