Antimicrobial Susceptibility of Invasive Streptococcus pneumoniae in Taiwan, 2008-2012

Ying-Yan Chen, Shu-Man Yao, Ya-Hui Chen, Shr-Fong Jiang, Tsung-Lin Kuo, Pei-Hsiu Kao, Lei-Ron Tseng, Yu-Lan Wang, Chuen-Sheue Chiang

2013 Vol.29 NO.19

Correspondence Author： Chuen-Sheue Chiang

Abstract：

       From January 2008 to December 2012, a total of 3,643 Streptococcus pneumoniae strains isolated from the confirmed cases of invasive pneumococcal disease were tested for the minimal inhibition concentrations (MIC) toward various antimicrobial agents. The susceptibility rates were 79.9% and 55.0% toward penicillins-type antimicrobial agents, amoxicillin and penicillin, respectively; 69.2% and 59.3% toward the third and the fourth generation cephalosporins, cefotaxime and cefepime, respectively; 94.7% and 95.3% toward quinolones-type antimicrobial agents, levofloxacin and moxifloxacin, respectively; 73.8%, 99.8%, 94.6% and 100.0% toward chloramphenicol, linezolid, telithromycin and vancomycin, respectively. The susceptibility rates were lower toward cabapenems-type antimicrobial agent, meropenem, and the sulfonamide-type antimicrobial agent, trimethoprim/sulfamethoxazole, 36.4% and 39.4%, respectively. The susceptibility rates toward erythromycin, tetracycline and clindamycin were the lowest, 9.6%, 9.0% and 24.2%, respectively. The susceptibility rates toward cefepime, clindamycin and meropenem continued to decline by year. The susceptibility rates toward amoxicillin and cefotaxime declined by year till 2011, and increased to 73.1% and 72.9% in 2012, respectively. In recent years, invasive infections caused by serotype 19A S. pneumoniae continued to increase and serotype 19A S. pneumoniae has become the most prevalent serotype in Taiwan. The non-susceptibility rates of serotype 19A S. pneumoniae towards amoxicillin, cefepime, cefotaxime, meropenem and penicillin were high, ranging from 81.6% to 97.2%. Among children younger than 5 years old, the highest proportion of infections was caused by serotype 19A S. pneumoniae, thus, the susceptibility rates toward the above mentioned antimicrobial agents among this age group were lower than those among other age groups, ranging from 13.0% to 54.8%. For strategies involved in prevention and treatment of invasive pneumococcal diseases, the result of this study indicated that antimicrobial resistance of S. pneumoniae was another issue that is required a close attention, in addition to the usage of vaccines.