The Epidemiological Characteristics of Pediatric Streptococcus Pneumoniae Isolated from Inpatients and Outpatients at Beijing Children’s Hospital

Background: The epidemiological data of Streptococcus pneumoniae isolates are important for the practice of treatment and prevention. This research aimed to explore the epidemiological characteristics of pediatric S. pneumoniae isolated from outpatients and inpatients. Methods: S. pneumoniae were isolated from unsterile samples of inpatients and outpatients younger than five years old between March 2013 and February 2014. The serotypes were determined by diagnostic pneumococcal antisera, and resistance against 13 antibiotics was tested by either the E-test or the disc diffusion method. The sequence types (STs) were analyzed with multilocus sequence typing (MLST). Results: The five dominant serotypes obtained from inpatients were 19F(32.9%), 19A(20.7%), 23F(10.7%), 6A(10.0%), and 14 (8.6%), while those in the outpatients were 19F (13.6%), 23F (12.9%), 6A (10.0%), 6B (10.0%), and 19A (7.9%). The coverage rates of the 7-, 10- and 13-valent pneumococcal vaccine formulations were high. The non-susceptibility to penicillin, cefuroxime, imipenem, erythromycin, and trimethoprim-sulfamethoxazole among the inpatient isolates were 7.1%, 92.8%, 65.7%, 100%, and 85.0%, respectively, while those among the outpatient isolates were 0.7%, 50.0%, 38.6%, 96.4%, and 65.7%, respectively. There were 45 and 81 STs detected from the pneumococci isolated from inpatients and outpatients, respectively. CC271 was more prevalent in inpatients. Conclusions: The pneumococcal vaccine related serotypes were still prevalent either in inpatient department or in outpatient department, which with serious antibiotic resistance. These results might be helpful for understanding the epidemiology of S. pneumoniae in Beijing. PCVs can prevent vaccine related serotypes. Therefore, universal immunization of PCVs should be implemented to prevent the spread of vaccine related serotypes of S. pneumoniae .