Evaluation of Verigene Blood Culture Test Systems for Rapid Identification of Positive Blood Cultures.

The performance of molecular tests using the Verigene Gram-Positive and Gram-Negative Blood Culture nucleic acid tests (BC-GP and BC-GN, resp.; Naosphere, Northbrook, IL, USA) was evaluated for the identification of microorganisms detected from blood cultures. Ninety-nine blood cultures containing Gram-positive bacteria and 150 containing Gram-negative bacteria were analyzed using the BC-GP and BC-GN assays, respectively.

Clonal and horizontal spread of the blaOXA-232 gene among Enterobacteriaceae in a Korean hospital.

All 16 Klebsiella pneumoniae isolates and both Escherichia coli isolates harbored the bla(OXA-232) and bla(CTX-M-15) genes. Furthermore, all 16 K. pneumoniae isolates belonged to a unique pulsed-field gel electrophoresis clone and were assigned to an identical sequence type (ST14).

Analysis of rotavirus genotypes in Korea during 2013: an increase in the G2P[4] genotype after the introduction of rotavirus vaccines.

Background: Group A rotavirus is the leading cause of acute gastroenteritis in children worldwide. We investigated G and P genotypes of group A rotavirus strains isolated from patients during 2013 and investigated which genotypes were identified from vaccinated patients.

Methods: From January to December 2013, 2235 fecal specimens were tested for rotavirus antigen, of which 374 specimens (16.

Changes in the incidence of Streptococcus pneumoniae bacteremia and its serotypes over 10 years in one hospital in South Korea.

Here, we examined the distribution of pneumococcal serotypes and the antibiotic susceptibility of Streptococcus pneumoniae in clinical blood isolates. The serotypes of 91 S. pneumoniae blood isolates, collected from January 2003 to March 2014, were identified by multiplex PCR and sequencing.

Analysis of reporting time for identification of methicillin-resistant Staphylococcus aureus carriers using ChromID MRSA.

We assessed the reporting times for identification of nasal methicillin-resistant Staphylococcus aureus (MRSA) carriers in 2011 in a university-affiliated hospital using surveillance cultures incubated for 1 and 2 days with ChromID MRSA (bioMérieux, France). Of 2,732 nasal swabs tested, MRSA was detected in 829 (85.6%) and 140 (14.

Evaluation of an immunochromatographic assay for the rapid and simultaneous detection of rotavirus and adenovirus in stool samples.

Background: We evaluated the analytical and clinical performances of the SD BIOLINE Rota/Adeno Rapid kit (SD Rota/Adeno Rapid; Standard Diagnostics, Inc., Korea), an immunochromatographic assay (ICA), for the simultaneous detection of rotaviruses and adenoviruses in human stool samples.

Methods: We tested 400 clinical stool samples from patients with acute gastroenteritis and compared the ICA results with the results obtained by using ELISA, enzyme-linked fluorescent assays (ELFA), PCR, and multiplex reverse transcription-PCR (mRT-PCR).

Evaluation of a new real-time reverse transcription polymerase chain reaction assay for detection of norovirus in fecal specimens.

A new real-time reverse transcription polymerase chain reaction (RT-PCR) assay, the AccuPower Norovirus Real-time RT-PCR Kit, was evaluated in detection of human norovirus in stool specimens. Studies for detection limit, dynamic range, reproducibility, and cross-reactivity were performed. A total of 281 fecal specimens were tested using the AccuPower Norovirus Real-time RT-PCR Kit, and the results were compared with those obtained using another real-time RT-PCR system.

Emergence of GII.4 Sydney norovirus in South Korea during the winter of 2012-2013.

Norovirus is the major cause of acute gastroenteritis worldwide. Between November 2012 and June 2013, 1718 stool samples were requested for norovirus antigen testing in the metropolitan areas of South Korea, and 91 samples were genotyped. The norovirus antigen-positive rate peaked at 52.

Evaluation of the SD Bioline Norovirus rapid immunochromatography test using fecal specimens from Korean gastroenteritis patients.

The analytical and clinical performance of a new rapid immunochromatography test, the SD Bioline Norovirus test, was evaluated for the detection of human norovirus in fecal specimens. The analytical performance studies were performed for detection limit, reproducibility, cross-reactivity, and interference. For comparison, 92 norovirus-positive stool samples and 126 norovirus-negative samples for which the results were confirmed by 2 different real-time PCR kits were used.

Analysis of reagent lot-to-lot comparability tests in five immunoassay items.

We investigated the degree of lot-to-lot reagent variation for 5 common immunoassay items. We measured the commercial as well as in-house controls for α-fetoprotein (AFP), ferritin, CA19-9, quantitative hepatitis B surface antigen (HBsAg), and hepatitis B surface antibody (anti-HBs) 10 times each by using both the old and the new lot of reagents whenever a reagent lot was changed, over a period of 10 months. The differences in the mean control values, the percent difference (% difference), and the difference to between-run standard deviation ratio (D:SD ratio) between successive lots were calculated.

Contamination of X-ray cassettes with methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus haemolyticus in a radiology department.

Background: We performed surveillance cultures of the surfaces of X-ray cassettes to assess contamination with methicillin-resistant Staphylococcus aureus (MRSA).

Methods: The surfaces of 37 X-ray cassettes stored in a radiology department were cultured using mannitol salt agar containing 6 µg/mL oxacillin. Suspected methicillin-resistant staphylococcal colonies were isolated and identified by biochemical testing.

Procalcitonin levels within 48 hours after burn injury as a prognostic factor.

Purpose: This study was performed to evaluate the clinical significance of procalcitonin in burn patients and to investigate whether procalcitonin levels at admission can be a prognostic indicator for sepsis and mortality.

Materials And Methods: Between January 2009 and December 2010, procalcitonin levels in 175 patients were tested within the first 48 hours after burn injury. Serum procalcitonin was measured using an enzyme-linked fluorescence assay.

Time-kill synergy tests of tigecycline combined with imipenem, amikacin, and ciprofloxacin against clinical isolates of multidrug-resistant Klebsiella pneumoniae and Escherichia coli.

This study evaluated the activity of tigecycline combined with imipenem, amikacin, and ciprofloxacin against clinical isolates of multidrug-resistant Klebsiella pneumoniae and Escherichia coli co-producing extended-spectrum β-lactamases and acquired AmpC β-lactamases. Broth microdilution tests were performed for cefotaxime, ceftazidime, cefepime, imipenem, amikacin, ciprofloxacin, and tigecycline. Time-kill synergy studies were tested for tigecycline plus imipenem, tigecycline plus amikacin, and tigecycline plus ciprofloxacin.

[Epidemiological analysis of norovirus infection between March 2007 and February 2010].

Background: Norovirus is a common cause of non-bacterial acute gastroenteritis worldwide, and norovirus infection shows symptoms such as vomiting and diarrhea in patients of all age groups. Mass outbreaks of norovirus infection have been recently reported in Korea. Herein, we investigated the epidemiological characteristics of acute norovirus gastroenteritis.

[Analysis of patients with positive acid-fast bacilli culture and negative T-SPOT.TB results].

Background: T-SPOT.TB is a sensitive test that detects interferon-gamma producing T-cells in tuberculosis patients following stimulation with tuberculosis-specific antigens. Our study was aimed to investigate the possible causes of false negative results of the test by analyzing the patients with positive acid-fast bacilli (AFB) culture and negative T-SPOT.

[Clinical usefulness of T-SPOT.TB test for the diagnosis of tuberculosis].

Background: Tuberculosis-specific ELISPOT assay (T-SPOT.TB, Oxford Immunotec, UK) is a test that detects interferon-gamma producing T-cells after stimulating patient's lymphocytes with two kinds of tuberculosis-specific antigens (ESAT-6 and CFP-10). We evaluated clinical usefulness of T-SPOT.

[Comparison of diagnostic utility between procalcitonin and C-reactive protein for the patients with blood culture-positive sepsis].

Background: Procalcitonin (PCT) is a relatively new marker for bacterial infections, and its diagnostic utility has been variable across the studies. We investigated the diagnostic utility of PCT for the patients with blood culture-positive sepsis, and compared it with that of C-reactive protein (CRP).

Methods: In 1,270 consecutive blood samples, PCT and CRP were simultaneously measured and results were compared according to the five categories of PCT concentrations (<0.

Broth microdilution method to detect extended-spectrum beta-lactamases and AmpC beta-lactamases in enterobacteriaceae isolates by use of clavulanic acid and boronic acid as inhibitors.

This study was designed to evaluate the performance of the broth microdilution (BMD) method to detect production of extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases in Enterobacteriaceae by using clavulanic acid (CA) and boronic acid (BA) as ESBL and AmpC beta-lactamase inhibitors, respectively. A total of 100 clinical isolates of Enterobacteriaceae were analyzed. Mueller-Hinton broth containing serial twofold dilutions of cefotaxime (CTX), ceftazidime (CAZ), aztreonam (ATM), or cefepime (FEP) with or without either or both CA and BA was prepared.

[Molecular typing of Staphylococcus aureus isolated from blood on the basis of coagulase gene polymorphism and toxin genes].

Background: Coagulase is produced by all strains of Staphylococcus aureus. The 3' coding region of the coagulase (coa) gene contains varying numbers of 81 bp tandem repeats. S.

Genetic background of nontraumatic osteonecrosis of the femoral head in the Korean population.

Major thrombophilic mutations have been identified as risk factors for nontraumatic osteonecrosis of the femoral head (ONFH) in Caucasians. We asked whether the genetic background of patients with ONFH in the Korean population was similar. We analyzed factor V G1691A mutation (factor V Leiden), prothrombin G20210A mutation, and methylenetetrahydrofolate reductase C677T and A1298C polymorphisms in 71 patients (53 men, 18 women) with ONFH.

Boronic acid disk tests for identification of extended-spectrum beta-lactamase production in clinical isolates of Enterobacteriaceae producing chromosomal AmpC beta-lactamases.

A study using boronic acid (BA) was designed to detect the extended-spectrum beta-lactamases (ESBLs) in Enterobacteriaceae producing chromosomal AmpC beta-lactamases. A total of 197 clinical isolates of Enterobacter spp. (n=100), Serratia marcescens (n=62) and Citrobacter freundii (n=35) were analysed.

Comparison of VERSANT Hepatitis B virus DNA 3.0 Assay with Digene Hybrid Capture II Hepatitis B virus DNA test in relation to clinical status of Hepatitis B virus.

Background: Some differences exist among various Hepatitis B virus (HBV) DNA quantification assays due to lack of standardization and besides clinical usefulness has not been firmly elucidated in Korean HBV patients.

Methods: We compared Bayer VERSANT HBV DNA 3.0 Assay (VERSANT 3.

[Panton-Valentine leukocidin positive Staphylococcus aureus isolated from blood in Korea].

Background: Panton-Valentine leukocidin (PVL) is a pore-forming toxin secreted by some Staphylococcus aureus strains and associated with skin and soft tissue infections; these strains are epidemiologically associated with current outbreaks of community-acquired methicillin-resistant S. aureus (MRSA) and with necrotizing pneumonia in healthy adults in USA and Europe. This study was performed to investigate the presence of PVL-positive S.

[Distribution of TT virus genotypes and genogroups in 69 healthy and 59 hepatitis B virus infected Korean individuals].

Background: TT virus (TTV) infection is highly prevalent in general population and patients with hepatitis B virus (HBV) infection. The aim of the present study was to determine the distribution of the genotypes and genogroups of TTV in healthy and HBV-infected individuals in Korea.

Methods: Distribution of TTV genotypes and genogroups was investigated in the serum samples of 69 healthy and 59 HBV-infected individuals.