Of the 214 isolates, 172 from sterile sites and 42 from non-sterile sites, the seven most frequent vaccine containing serotypes from isolates from sterile sites in patients <5 years old were 6B, 23F, 14, 19F, 19A, 6A, and 4 or 9V, accounting for 81.2% of all isolates. For the patients ≥65 years old, the seven most common serotypes were 6B, 23F, 19A, 4, 9V, 19F

and 3, accounting for 56.5% of all isolates (Table 1). Serotype 6B and 23F were the most frequently identified serotype from sterile sites in patients <5 and ≥65 years old. The serotype coverage of vaccines is shown in Table 2. PCV-7 covered 70.3%, 43.6%, and 43.5% of S. pneumoniae isolates from sterile sites in patients <5 years, 5–64 years, and ≥65 years old, respectively. PCV-13 provided coverage to 81.2%, 59.7%, and 60.9% of isolates from patients in these age groups, respectively. PI3K inhibitor Other PCVs (PCV-9, PCV-10, PCV-11) had similar coverage as PCV-7 in patients <5 years old, but slightly increased coverage in patients 5–64 years and ≥65 years (range 43.5–52.2%). In children <5 years of age, PCV-7 and PCV-13 covered 61.9% and 76.2% of isolates from non-sterile sites, respectively. For the analysis in this study, we used meningitis criteria for learn more S. pneumoniae isolates from CSF only, and non-meningitis

criteria for those from other sites ( Table 3). With this analysis strategy, we found the penicillin susceptibility rates in isolates from sterile sites were 93.8%, 88.7% and 95.7% in patients <5, 5–64 and ≥65 years old, respectively. The corresponding percentages for cefotaxime susceptibility were 90.6%, 98.4% and

93.5%, respectively. In contrast, penicillin- and cefotaxime-susceptibility rates in isolates from non-sterile sites in patients <5 years old using criteria for non-meningitis and with oral penicillin treatment were 26.2% and 78.6%, respectively. The MICs for all antibiotics tested in isolates from non-sterile sites were higher than those from sterile sites. Susceptibility to ofloxacin ranged 92.2–100%, and all isolates were susceptible to ciprofloxacin. PCV-7 covered 83% and 100% of penicillin and cefotaxime non-susceptible isolates, respectively, CYTH4 from sterile sites in patients <5 years old. We demonstrated comparison of penicillin susceptibility of isolates from sterile sites in <5 years old using the former and the newer criteria in Fig. 1. If we used the former criteria, only 28.1% would be penicillin-susceptible S. pneumoniae (PSSP). Our study describes the serotype distribution and antimicrobial susceptibilities of invasive pneumococcal isolates collected in Thailand from 2006 to 2009. Data on a small set of non-invasive isolates from children under five were also presented.