133. The Changing Phenotypes and Genotypes of Invasive Pneumococcal Isolates From Children in Shenzhen During 2013–2017

Abstract

BackgroundThe phenotypes and genotypes of Streptococcus pneumoniae (Spn.) isolated from children with invasive pneumococcal diseases (IPDs) were changed in these years. The purpose of this study was to monitor this mutation trends before the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in China.MethodsStrains were isolated from children less than 14 years old between January 2013 and May 2017 in Shenzhen Children’s Hospital. Serotypes, antibiotic resistance, and genotypes of these isolates were determined using capsular swelling, E-test, and multi-locus sequence typing, respectively.ResultsA total of 94 Spn. strains were isolated, which belonged to 15 serotypes. The five most prevalent serotypes were 19F (25.5%), 19A (19%), 14 (17%), 23F (7.5%), and 6B (9.6%). The other two serotypes (19C and 15) were non-vaccine types. We found 42 sequence types (STs) for these isolates. The most abundant STs were ST271 (24.4%), ST876 (17%), and ST320 (10.6%), mainly related to 19F, 14, and 19A, respectively. The potential coverage of PCV13 was 87.2%. Among non-meningitis isolates, the resistance rates to penicillin and ceftriaxone were 0% and 2%. However, the meningitis isolates showed universal resistance to penicillin (80%) and ceftriaxone (20%). Most of these isolates (95.7%) were resistant to erythromycin, and 66 (70.2%) strains carried the ermB gene and 24 (25.5%) strains carried both the ermB and mefA/E genes. Serotype 19A showed the highest minimum inhibitory concentration (MIC) for penicillin than the other serotypes, but no significant difference in penicillin MIC among the three main STs (ST271, ST320, and ST876).ConclusionThe phenotypes and genotypes of invasive pneumococcal isolates from children in Shenzhen have changed with the passage of time. Compared with PCV7, PCV13 can more effectively protect Chinese children from IPDs. To some extent, these changes are possibly related to the usage of antibiotics and vaccines.Disclosures All authors: No reported disclosures.