OBJECTIVETo investigate the antimicrobial resistance of invasive and non-invasive Streptococcus pneumoniae (SP) strains in children and to provide a basis for proper use of antimicrobial drugs in the treatment of SP infection.

METHODSSeventy children who were diagnosed with invasive pneumococcal diseases (IPD) between January 2009 and December 2013 were enrolled, and 164 children with lower respiratory tract infection caused by SP were randomly selected as the control group. The samples from sterile sites (blood, cerebrospinal fluid, etc) of children with IPD, as well as the sputum samples of children in the control group, were collected for bacterial culture, and the drug susceptibility tests for isolated SP strains were conducted.

RESULTSA total of 82 invasive strains of SP were isolated from sterile sites of 70 children with IPD; 49 strains (60%) were isolated from blood, and 19 strains (23%) from cerebrospinal fluid. The detection rate of invasive SP strains decreased from 2009 to 2013 (P<0.01). The total detection rates of penicillin-nonsusceptible SP from the invasive and non-invasive strains were 27% and 17% respectively (P>0.05). Among invasive strains, the penicillin-nonsusceptible SP strains had significantly higher rates of insusceptibility to cefotaxime, ceftriaxone, and cefepime than the penicillin-susceptible SP (P<0.01). There were significant differences in the rates of insusceptibility to cefotaxime, ceftriaxone, and meropenem between the sensitive and non-sensitive SP strains (P<0.05). The multidrug resistance rates of the invasive and non-invasive SP strains were 89% and 93% respectively (P>0.05).

CONCLUSIONSInvasive SP can easily invade the blood in children, but the total detection rate has decreased year by year. The results of drug sensitivity tests have guiding significance for proper use of antimicrobial drugs for different SP infections.