Prevalence of antimicrobial resistance of Streptococcus pneumoniae in Chinese children： four hospitals surveillance

Objective To investigate the nasal carriage of antibiotic-resistant pneumococci in children of < 5 years old in the following four cities, Beijing, Shanghai, Guangzhou and Xi'an.Methods A total of 647 pneumococci strains were isolated and detected. Minimal inhibition concentrations (MICs) of antibiotics were determined by E-test. Disk diffusion test was used for the measurement of antimicrobial susceDtibilitv.Results Prevalence of penicillin non-susceptible Streptococcus pneumoniae in the four cities was 41%, with Guangzhou (60. 8%) ranking first, followed by Xi' an (45%), Shanghai (37%) and Beijing (25. 9%). The majority of penicillin non-susceptibility isolates (23.9% -53.8%) had a low level of resistance (MIC 0. 64 -1.5μg/ml). The most sensitive antimicrobials in terms of percentage of susceptible organisms were amoxicillin-clavulanic acid (99.4%), followed by ceftriaxone (92. 1% ) ; cefurxime and cefaclor were slightly more sensitive than penicillin with susceptibility of 74. 8% and 77. 9%. Erythromycin, tetracycline and TMP-SMZ were highly resistant (83. 6%, 82.1% and 76.2% respectively). Among erythromycin resistant isolates, 100% were resistant to azithromycin, 98. 6% to clarithromycin, 97.2% to roxithromycin and spiramycin, and 96. 6% to clindamycin. 97.2% (141/145) were typical of the macrolides-lincosamides-streptogramons B(MLSB) resistance phenotype, and 2, 8% (4/145) were M phenotype. The group of PRSP was with significantly higher rates of non-susceptibility for ceftriaxone (18. 4% ), cefurxime (58. 6% ), cefaclor (53.4%), compared with the group of PEN-S (0. 5%, 1.8% and 0.2%, respectively) and the rate of multi-drug resistance in the isolates of PRSP group (92. 9% ) was significantly higher than that of PEN-S group (59. 2% ).Conclusion The rates of penicillin and multi-drug resistance among isolates of pneumococci carried nasally in are high children and the high prevalence of multi-drug resistance in the Chinese population may be becoming one of the most serious problems in this century.