Serotype Distribution and Antimicrobial Resistance of Invasive and Noninvasive Streptococcus pneumoniae Isolates in Korea between 2014 and 2016.

BACKGROUND: Several factors contribute to differences in Streptococcus pneumoniae serotype distribution. We investigated the serotype distribution and antimicrobial resistance of S. pneumoniae isolated between 2014 and 2016 in Korea. METHODS: We collected a total of 1,855 S. pneumoniae isolates from 44 hospitals between May 2014 and May 2016, and analyzed the serotypes by sequential multiplex PCR. We investigated the distribution of each serotype by patient age, source of the clinical specimen, and antimicrobial resistance pattern. RESULTS: The most common serotypes were 11A (10.1%), followed by 19A (8.8%), 3 (8.5%), 34 (8.1%), 23A (7.3%), and 35B (6.2%). The major invasive serotypes were 3 (12.6%), 19A (7.8%), 34 (7.8%), 10A (6.8%), and 11A (6.8%). Serotypes 10A, 15B, 19A, and 12F were more common in patients ≤5 years old, while serotype 3 was more common in patients ≥65 years old compared with the other age groups. The coverage rates of pneumococcal conjugate vaccine (PCV)7, PCV10, PCV13, and pneumococcal polysaccharide vaccine 23 were 11.8%, 12.12%, 33.3%, and 53.6%, respectively. Of the 1,855 isolates, 857 (46.2%) were multi-drug resistant (MDR), with serotypes 11A and 19A predominant among the MDR strains. The resistance rates against penicillin, cefotaxime, and levofloxacin were 22.8%, 12.5%, and 9.4%, respectively. CONCLUSIONS: There were significant changes in the major S. pneumoniae serotypes in the community. Non-PCV13 serotypes increased in patients ≤5 years old following the introduction of national immunization programs with the 10- and 13-polyvalent vaccines.

Increasing prevalence of blaOXA-23-carrying Acinetobacter baumannii and the emergence of blaOXA-182-carrying Acinetobacter nosocomialis in Korea.

Carbapenem-resistant Acinetobacter spp. have been increasingly reported worldwide with the production of OXA-type carbapenemases as the main mechanism of carbapenem resistance. The prevalent bla(OXA) genes are known to vary significantly depending on time and place of isolation. We investigated the prevalence of bla(OXA) genes by PCR in Acinetobacter spp. isolated in Korea. Among a total of 336 isolates collected from Hospital A from 2002 to 2011, the overall proportion of bla(OXA)-23-like, ISAba1-associated bla(OXA-51)-like, and bla(OXA-182) genes were 44.0%, 49.7%, and 5.1%, respectively. The bla(OXA-58)-like gene was detected in only 1 isolate. A drastic increase in Acinetobacter isolates with bla(OXA-23)-like genes and a decrease in isolates harboring ISAba1-associated bla(OXA-51)-like genes have been observed since the mid-2000s. The bla(OXA-23)-like genes were detected in all carbapenem-nonsusceptible isolates collected in 2011 from 9 hospitals. The OXA-182, which belongs to the fifth group of OXA-type carbapenemase, was detected in Acinetobacter baumannii isolates recovered as early as 2002. It is worrisome results that bla(OXA-182)-carrying Acinetobacter nosocomialis has emerged and caused outbreaks of infection.

Maintained seroprevalence of toxoplasmosis among the residents of Jeju island, Korea.

Seroepidemiological status of toxoplasmosis among the residents of Jeju island was surveyed and evaluated by ELISA with crude extract of Toxoplasma gondii. The sera of 2,348 residents (male 1,157 and female 1,191) were collected and checked for the IgG antibody titers, which showed 13.2% positive rate (309 sera). The positive rates were increasing gradually according to the age from 4.3% in teenage to 20.6% in seventies. The positive rates were significantly different between the sex by 16.2% for male and 10.2% for female (P<0.05). This positive rate of toxoplasmosis in Jeju island residents is regarded relatively higher than any other regions of Korea. And the high positive rate may be maintained continuously among Jeju island residents without any clear reasons until now but due to some parts peculiar socio-cultural tradition of Jeju island. Therefore, it is necessary to study further the epidemiology of toxoplasmosis of Jeju island.

Co-transplantation of human mesenchymal stem cells promotes human CD34+ cells engraftment in a dose-dependent fashion in NOD/SCID mice.

Mesenchymal stem cells (MSCs) have recently been identified and characterized in humans. Moreover, MSC secrete cytokines that can support hematopoietic progenitor growth. In the present study, we evaluated whether the efficacy of hematopoietic stem cell transplantation is improved by their co-transplantation with MSC, and whether this is positively correlated with the dose of infused MSCs. Accordingly, irradiated NOD/SCID mice were transplanted with 1 x 10(5) human CD34+ cells in the presence or absence of culture expanded MSCs (1 x 10(6) or 5 x 10(6)). We evaluated human hematopoietic cell engraftment by flow cytometry and assessed MSC tissue distributions by fluorescence in situ hybridization. We found that CD45+ and CD34+ cell levels were significantly elevated in a dose-dependent manner in co-transplanted mice 4 weeks after transplantation. The engraftments of CD33+ and CD19+ cells also increased dose-dependently. However, the engraftment of CD3+ cells did not increase after co-transplantation with MSCs. Human Y chromosome+ cells were observed in multiple tissues and were more frequently observed in mice co-transplanted with 5 x 10(6) rather than 1 x 10(6) MSCs. These results suggest that MSCs are capable of enhancing hematopoietic cell engraftment and distribution in multiple organs in a dose-dependent fashion.

Successful eradication of relapsed primary effusion lymphoma with high-dose chemotherapy and autologous stem cell transplantation in a patient seronegative for human immunodeficiency virus.

Primary effusion lymphoma (PEL) is a recently recognized disease that occurs most often in immunosuppressed patients, either with human immunodeficiency virus (HIV) or in the posttransplantation setting, and it occasionally occurs in nonimmunosuppressed patients. Patients present with lymphomatous effusions in serous cavities--pleura, pericardium, or peritoneum--without any identifiable tumor mass. PEL rarely responds to systemic chemotherapy, and the prognosis is poor, with a median survival time of less than 6 months for most cohorts. A standard treatment for PEL has not yet been identified. We describe a patient with HIV-seronegative PEL who relapsed after combination chemotherapy and then underwent successful treatment with high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT). The treatment was well tolerated, and the patient has been in remission for 12 months after HDC and ASCT.

A phase II study of irinotecan, 5-fluorouracil and leucovorin for treatment in patients with previously untreated advanced colorectal cancer.

PURPOSE: We prospectively conducted a non-randomized phase II trial to evaluate the efficacy and safety of combination irinotecan, leucovorin (LV) and 5-fluorouracil (FU) as a first-line regimen for treating patients with previously untreated advanced colorectal cancer (CRC). MATERIALS AND METHODS: Twenty-six previously untreated patients with advanced, recurrent or metastatic CRC were enrolled in this study. The patients received either irinotecan 180 mg/m(2) on day 1 with LV bolus of 200 mg/m(2) and FU bolus of 400 mg/m(2), and this was followed by FU continuous infusion of 600 mg/m(2) on day 1 and day 2 (the FOLFIRI regimen), or they were treated with LV bolus of 400 mg/m(2) and FU bolus of 400 mg/m(2) followed by FU continuous infusion of 2,400 mg/m(2) for 46 hours (the simplified FOLFIRI regimen), and these treatments were repeated every 2 weeks until disease progression. RESULTS: The objective response rate was 23.1% (6/26) respectively, for both treatments. The median time to progression was 5.3 months (range: 0.4 approximately 19.9), and the overall survival was 11.2 months (range: 0.5 approximately 52.3). The prognostic factor for longer survival was the Eastern Cooperative Oncology Group (ECOG) performance status (PS). The non-hematological toxicities were similar for both treatment groups, with more frequent grade >or=3 neutropenia being noted for the simplified FOLFIRI regimen. CONCLUSION: The biweekly irinotecan based regimen was demonstrated to have a moderate antitumor activity with acceptable toxicity profiles, and the ECOG PS was the independent prognostic factor.

Combination of gemcitabine and cisplatin as first-line therapy in advanced non-small-cell lung cancer.

PURPOSE: The prognosis of patients with advanced non-small-cell lung cancer (NSCLC) is extremely poor. Many prospective randomized trials on patients with advanced NSCLC suggested systemic chemotherapy improves both the survival and quality of life. A phase II trial was conducted to evaluate the efficacy and safety profile of the combination chemotherapy of gemcitabine and cisplatin in advanced NSCLC. MATERIALS AND METHODS: Forty-four patients with locally advanced or metastatic NSCLC were enrolled. The patients received a cisplatin, 75 mg/m(2), infusion over 30 minutes on days 1, followed by a gemcitabine, 1,250 mg/m(2), infusion over 30 minutes on days 1 and 8 every 3 weeks. RESULTS: The median age of the patients was 64 years (range: 27 approximately 75). Forty-one patients were assessable for response and toxicity analyses. The overall response rate was 53.6%, but with no complete remissions. The median time to progression was 5.6 months (range: 1 approximately 15.4). The median survival was 14.2 months (95% confidence interval (CI), 13.8 approximately 22.5). A total of 179 cycles were administered, with a median of 4 cycles of chemotherapy, ranging from 2 to 9 cycles. The most common hematological toxicities were NCI grades 3/4 neutropenia (24%) and thrombocytopenia (7.8%). The most common non-hematological toxicity was fatigue (42.4%). There were no life-threatening toxicity or treatment related mortalities. The median duration of follow up was 9.4 months, ranging from 1.6 to 30.3 months. CONCLUSION: In this trial, the combination of gemcitabine and cisplatin showed significant activity, with acceptable and manageable toxicities as a first-line regimen for patients with advanced NSCLC.