[Antimicrobial resistance and serotype distribution of Streptococcus pneumoniae isolated from multi-centers across China, 2010 - 2011].

OBJECTIVE:To investigate the trends of resistance of S. pneumoniae and to evaluate the potential coverage of pneumococcal conjugate vaccine. METHODS:The antibiotic susceptibility and serotype distribution of 471 pneumococcal strains isolated from pneumococcal diseases in 13 hospitals across China during 2010 to 2011 were studied. In vitro susceptibility to 15 antimicrobial agents was determined by agar dilution method. Serotyping of S. pneumoniae was performed by using latex and quelling reaction. Vaccine coverage by 7-, 10-, 13- and 23- valent conjugate vaccines was estimated by calculating the percentage of isolates that belonged to the serotypes included in the vaccines. RESULTS:Among all strains tested, 50.1% (236/471) was resistant to penicillin (Oral breakpoint, MIC ≥ 2 mg/L). Overall, 27.4% (129/471), 60.3% (284/471), 58.8% (277/471) and 18.5% (87/471) of S. pneumoniae were resistant to amoxicillin/clavulanate, cefaclor, cefuroxime and ceftriaxone, respectively.1.5% (7/471) of all stains were resistant to levofloxacin and 0.6% (3/471) of all strains were resistant to moxifloxacin. The resistance rates to other antibiotic agents, such as erythromycin, clindamycin, tetracycline, trimethoprim/sulfamethoxazole, and chloramphenicol, were 93.2% (439/471), 88.7% (417/471), 89.6% (422/471), 62.8% (296/471) and 22.1% (104/471), respectively. The most prevalent serotype was 19F (112, 23.8%), followed by 19A (63, 13.4%), 3 (48, 10.2%), 14 (43, 9.1%), 23F (29, 6.2%), 15 (25, 5.3%) and 6A (23, 4.9%). The potential coverage by 7- and 13-valent pneumococcal conjugate vaccines was 45.3% (213/471) and 76% (358/471), respectively. The potential coverage of PCV7 and PCV13 in children were 59.0% (72/122) and 86.9% (106/122), and the potential coverage of PCV7 and PCV13 in adult were 42.3% (94/222) and 73.4% (163/222). CONCLUSIONS:The antibiotic resistance of S. pneumoniae was serious in China, especially to tetracycline, erythromycin and clindamycin. The majority of serotypes 19A and 19F was penicillin-resistant. The potential coverage of PCV7 and PCV13 in children was higher than those in adult. PCV13 could cover most of the isolates, especially for penicillin-resistant S. pneumoniae.