Streptococcus pneumoniaeis a significant pathogen with high mortality and morbidity prices. is involved with the majority of Z-FL-COCHO IC50 invasive pneumococcal illnesses and antimicrobial resistances. The 23-valent polysaccharide vaccine (PPV23) and a 7-valent pneumococcal conjugate vaccine (PCV7) had been recommended for older people (65 years of age) and kids (5 years of age), respectively. In Korea, PCV7, which shields against the key intrusive serotypes (4, 6B, 9V, 14, 18C, 19F, and 23F), was released in 2003 for babies and small children. The introduction of PCV7 in america produced a reduction in both intrusive and non-invasive pneumococcal illnesses due to these vaccine serotypes [6, 7]. Nevertheless, usage of PCV7 offers led to adjustments in common serotypes; it tended to improve the PCV7 nonvaccine serotypes, 19A especially, worldwide [8C10]. Another pneumococcal conjugate vaccine (PCV10 and PCV7 with serotypes 1, 5, and 7F added) and a 13-valent vaccine (PCV13 and PCV10 with serotypes 3, 6A, and 19A added) had been released in Korea this year 2010. Since May 2014, pneumococcal vaccination has been Z-FL-COCHO IC50 provided for free as a routine national vaccine program, including PCV10, PCV13, and PPSV23 in South Korea. Since the first detection ofS. pneumoniaewith high resistance to penicillin and other antibiotics in 1977, high rates of antimicrobial resistance inS. pneumoniaehave been a serious concern worldwide [11C13]. In Asian countries, beta-lactam and macrolide resistance are very high, and multidrug resistance (MDR) also is common [4, 14C16]. In 2008, the Clinical Laboratory and Standard Institute (CLSI) guideline changed the resistance breakpoint of nonmeningitisS. pneumoniaefor penicillin from 2?S. pneumoniaeisolates collected from patients at a tertiary-care hospital in Korea from January 2008 to June 2014 were included. The isolates were identified by colony morphology, gram staining, optochin susceptibility, and other biochemical reactions using VITEK2 system. All isolates were stored at ?70C using 10% skim-milk until use. 2.2. Serotyping Serotyping Z-FL-COCHO IC50 was performed by capsular swelling (Quellung reaction) using Pneumotest antisera kit (Statens Serum Institut, Copenhagen, Denmark). For determining the serotype, pool antisera were used as recommended by the manufacturer. In order to determine additional serotypes, some factor antisera and serotype-specific polymerase chain reaction (PCR) recommended by the U.S. Centers for Disease Control and Prevention (CDC, http://www.cdc.gov/streplab/downloads/pcr-oligonucleotide-primers.pdf) were used [21]. Serotypes were Z-FL-COCHO IC50 classified into vaccine serotype (VT) and nonvaccine serotype (NVT). Vaccine serotype means a serotype included in PCV7 (serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F), PCV10 (serotypes 1, 5, and 7F added to PCV7), PCV13 (serotypes 3, 6A, and 19A added to PCV10), and PPSV23 (serotypes 2, 8, 9N, 10A, 11A, 12F, 15B, 17F, 20, 22F, and 33F added to PCV13, except for 6A). Nonvaccine serotype is the serotype which is not covered by PCV7, PCV10, PCV13, and PPSV23. 2.3. Antimicrobial Susceptibility Antimicrobial susceptibilities were determined using the Microscan system, and the susceptibility interpretive criteria were those published in the relevant guidelines of the Clinical and Laboratory Standards Institute (CLSI). Separate interpretive breakpoints were used to define the resistance to penicillin, cefepime, cefotaxime, and ceftriaxone for meningeal isolates. The following antimicrobial agents were tested: amoxicillin, azithromycin, cefaclor, cefepime, cefotaxime, ceftriaxone, cefuroxime, chloramphenicol, clindamycin, erythromycin, levofloxacin, meropenem, penicillin, tetracycline, sulfamethoxazole/trimethoprim (SXT), and vancomycin. The Food and Drug Administration defines multiresistance as resistance to two or more of the five classes of antibacterial agents represented by erythromycin, cefuroxime, SXT, penicillin, and tetracycline [22]. The resistance to cefotaxime and ceftriaxone was analyzed instead of that Z-FL-COCHO IC50 to cefuroxime and SXT. Macrolide resistance was defined by the erythromycin susceptibility test results. We assessed differences in serotypes by age group, clinical specimens, surveillance periods, and resistance types. The data was analyzed with the software IBM SPSS version 22, using chi-square test. 3. Results 3.1. Characteristics ofS. pneumoniaeIsolates The numbers ofS. pneumoniaeisolates by period are as follows: 198 isolates (52.4%) were obtained between 2008 and 2010 (period I) and 180 isolates (47.6%) between 2011 and 2014 (period II). Of the 378 isolates, 265 (70.1%) and 113 (29.9%) were from man and female individuals, respectively. Many (197; 52.1%) had been obtained from older people (>65 years of age) and Gadd45a 16 (4.2%) from kids (5 years of age). The mean age group (SD) from the individuals was 60.8 19.