Jae-Bum Jun

Incidence, Characteristics, and Outcomes of Staphylococcus lugdunensis Bacteremia

ABSTRACT Of 63 patients with Staphylococcus lugdunensis bacteremia, 15 (23.8%) had clinically significant bacteremia, with an incidence of 1.3 cases per 100,000 admissions. Of the five patients with community-acquired S. lugdunensis bacteremia, three had endocarditis. Catheters were the most common portal of entry for health-care-associated or hospital-acquired bacteremia. Only one patient died of bacteremia-related causes.

Early Acute Kidney Injury Is a Risk Factor That Predicts Mortality in Patients Treated with Colistin

The nephrotoxicity of colistin has been reported in the literature. A previous report has shown that acute kidney injury (AKI) occurred after an average of 13.5 days, but we have experienced that AKI developed with colistin administration earlier. We investigated clinical features of patients who developed AKI according to the time of AKI development after colistin use. We retrospectively collected the data of the patients who were admitted to 4 hospitals between January 2007 and May 2009. This study included 119 patients who had received intravenous colistin for over 72 h. We compared the early AKI group (AKI developed within 7 days) with the late AKI group. The patients’ age was 64.1 ± 14.0 years. AKI occurred in 65 of the 119 patients (54.6%). The duration of colistin use was 7.7 ± 6.4 days. AKI occurred in 46 patients within 7 days after colistin treatment and in 19 patients after 7 days. The patients with early AKI had a higher mortality rate than those with late AKI (OR: 4.37, 95% CI: 1.34, 14.18). In conclusion, clinicians might be cautioned that the mortality rate is higher for the patients with early occurrence of AKI than that for the patients with late occurrence of AKI.

Prevalence of aac(6′)-Ib-cr Encoding a Ciprofloxacin-Modifying Enzyme among Enterobacteriaceae Blood Isolates in Korea

ABSTRACT The aac(6′)-Ib gene was detected in 86 of 555 (15.5%) Enterobacteriaceae isolates. Among these 86 aac(6′)-Ib-positive isolates, 19 (22.0%) were positive for aac(6′)-Ib-cr: 4 of 31 (12.9%) Enterobacter spp., 7 of 13 (53.8%) Escherichia coli isolates, and 8 of 42 (19.0%) Klebsiella pneumoniae isolates. There was a strong association between aac(6′)-Ib-cr and OXA-1 and CTX-M-1 group β-lactamase genes. One aac(6′)-Ib-positive K. pneumoniae isolate carried both aac(6′)-Ib-cr and qnrS.

Severe Fever with Thrombocytopenia Syndrome in South Korea, 2013-2015

Background Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that was recently identified in China, South Korea and Japan. The objective of the study was to evaluate the epidemiologic and clinical characteristics of SFTS in South Korea. Methods/Principal Findings SFTS is a reportable disease in South Korea. We included all SFTS cases reported to the Korea Centers for Disease Control and Prevention (KCDC) from January 2013 to December 2015. Clinical information was gathered by reviewing medical records, and epidemiologic characteristics were analyzed using both KCDC surveillance data and patient medical records. Risk factors for mortality in patients with SFTS were assessed. A total of 172 SFTS cases were reported during the study period. SFTS occurred throughout the country, except in urban areas. Hilly areas in the eastern and southeastern regions and Jeju island (incidence, 1.26 cases /105 person-years) were the main endemic areas. The yearly incidence increased from 36 cases in 2013 to 81 cases in 2015. Most cases occurred from May to October. The overall case fatality ratio was 32.6%. The clinical progression was similar to the 3 phases reported in China: fever, multi-organ dysfunction, and convalescence. Confusion, elevated C-reactive protein, and prolonged activated partial thromboplastin times were associated with mortality in patients with SFTS. Two outbreaks of nosocomial SFTS transmission were observed. Conclusions SFTS is an endemic disease in South Korea, with a nationwide distribution and a high case-fatality ratio. Confusion, elevated levels of C-reactive protein, and prolonged activated partial thromboplastin times were associated with mortality in patients with SFTS.

IL-33–Induced Hematopoietic Stem and Progenitor Cell Mobilization Depends upon CCR2

IL-33 has been implicated in the pathogenesis of asthma, atopic allergy, anaphylaxis, and other inflammatory diseases by promoting the production of proinflammatory cytokines and chemokines or Th2 immune responses. In this study, we analyzed the in vivo effect of IL-33 administration. IL-33 markedly promoted myelopoiesis in the bone marrow and myeloid cell emigration. Concomitantly, IL-33 induced hematopoietic stem and progenitor cell (HSPC) mobilization and extramedullary hematopoiesis. HSPC mobilization was mediated mainly through increased levels of CCL7 produced by vascular endothelial cells in response to IL-33. In vivo treatment of IL-33 rapidly induced phosphorylation of ERK, JNK, and p38, and inhibition of these signaling molecules completely blocked the production of CCL7 induced by IL-33. Consistently, inhibitor of CCR2 markedly reduced IL-33–mediated HSPC mobilization in vivo and migration of HSPCs in response to CCL7 in vitro. IL-33–mobilized HSPCs were capable of homing to, and of long-term reconstitution in, the bone marrow of irradiated recipients. Immune cells derived from these recipients had normal antifungal activity. The ability of IL-33 to promote migration of HSPCs and myeloid cells into the periphery and to regulate their antifungal activity represents a previously unrecognized role of IL-33 in innate immunity. These properties of IL-33 have clinical implications in hematopoietic stem cell transplantation.

Clinical characteristics and outcomes of pneumococcal bacteremia in adult patients with liver cirrhosis

Few studies have assessed the clinical characteristics and outcomes of invasive pneumococcal diseases in cirrhotic patients. We reviewed the medical records of adult cirrhotic patients with pneumococcal bacteremia from January 1997 to April 2006. During this time, 62 episodes of pneumococcal bacteremia occurred in 59 patients with liver cirrhosis, 45 (76.3%) of whom were classified as Child-Pugh grade C. The most common source of infection was spontaneous bacterial peritonitis (SBP) (45.8%), followed by primary bacteremia (40.7%) and pneumonia (10.1%). The 30-day mortality rate was 16.9%, with all fatalities in patients classified as Child-Pugh grade C. The median model for end-stage liver disease score of patients who died was significantly higher than that of survivors (26.5 versus 17.0, P=0.001). Pneumococcal bacteremia in adult cirrhotic patients was more commonly associated with SBP than with pneumonia. Most cases of bacteremia and fatal outcomes occurred in patients with advanced cirrhosis.

The burden of nosocomial staphylococcus aureus bloodstream infection in South Korea: a prospective hospital-based nationwide study

BackgroundWe estimated the nationwide burden of nosocomial S. aureus bloodstream infection (SA-BSI), a major cause of nosocomial infection, in South Korea.MethodsTo evaluate the nationwide incidence of nosocomial SA-BSI, cases of SA-BSI were prospectively collected from 22 hospitals with over 500 beds over 4?months. Data on patient-days were obtained from a national health insurance database containing the claims data for all healthcare facilities in South Korea. The additional cost of SA-BSI was estimated through a matched case?control study. The economic burden was calculated from the sum of the medical costs, the costs of caregiving and loss of productivity.ResultsThree hundred and thirty nine cases of nosocomial SA-BSI were included in the study: 254 cases of methicillin-resistant SA-BSI (MRSA-BSI) and 85 cases of methicillin-susceptible SA-BSI (MSSA-BSI). Death related to BSI occurred in 81 cases (31.9%) of MRSA-BSI and 12 cases (14.1%) of MSSA-BSI. The estimated incidence of nosocomial MRSA-BSI was 0.12/1,000 patient-days and that of nosocomial MSSA-BSI, 0.04/1,000 patient-days. The estimated annual cases of nosocomial BSI were 2,946 for MRSA and 986 for MSSA in South Korea. The additional economic burden per case of nosocomial SA-BSI was US

Clinical and Economic Consequences of Failure of Initial Antibiotic Therapy for Patients with Community-Onset Complicated Intra-Abdominal Infections

20,494 for MRSA-BSI and

Bacteriology and Changes in Antibiotic Susceptibility in Adults with Community-Acquired Perforated Appendicitis

6,914 for MSSA-BSI. Total additional annual cost of nosocomial SA-BSI was

Effect of Early Plasma Exchange on Survival in Patients with Severe Fever with Thrombocytopenia Syndrome: A Multicenter Study

67,192,559.ConclusionIn view of the burden of nosocomial SA-BSI, a national strategy for reducing nosocomial SA-BSI is urgently needed in South Korea.