No abstract available.
Bacteria, Anaerobic*

Epstein-Barr virus (EBV) latent infection transforms B lymphocytes into proliferating lymphoblastoid cell lines (LCLs). EBV latent infection membrane protein 1 (LMP1) is required for EBV-mediated B lymphocyte transformation, and LMP1-induced NF-kappaB activation is essential for LCL survival. Previously, it was reported that the level of reactive oxygen species (ROS) and the expression of apoptosis signal-regulating kinase 1 (ASK1) are elevated in EBV-positive Burkitt's lymphoma (BL) cells, the potential role of ASK1 in LMP1-induced NF-kappaB activation was thus investigated in this study. In EBV-positive BL cells, ASK1 was highly expressed and activated. In addition, TRAF6-ASK1 interaction was significantly increased in EBV-positive BL cells. Interestingly, the expression of LMP1 alone facilitated ASK1 activation. The expression of a dominant negative ASK1 mutant (ASK1KM) strongly blocked LMP1-induced NF-kappaB activation. Furthermore, LMP1-induced NF-kappaB activation was significantly reduced in ASK1 knock out (ASK1-/-) mouse embryonic fibroblasts (MEFs). Taken together, these results demonstrate that ASK1 is activated by LMP1 and is critical for LMP1-induced NF-kappaB activation.
Animals ; B-Lymphocytes ; Burkitt Lymphoma ; Cell Line ; Fibroblasts ; Herpesvirus 4, Human ; Lymphocyte Activation ; MAP Kinase Kinase Kinase 5 ; Membrane Proteins ; Mice ; NF-kappa B ; Reactive Oxygen Species

No abstract available.
Bacteria, Anaerobic*

No abstract available.
Bacteria, Anaerobic*

No abstract available.
Bilophila*

No abstract available.
Bilophila*

BACKGROUND: Plasmid-mediated AmpC beta-lactamases (PABLs) have been detected in the strains of Escherichia coli, Klebsiella spp., Proteus mirabilis, and Salmonella spp. PABLs may be difficult to detect and might interfere in the therapeutic and infection-control processes. Although several PABL-detection methods based on phenotypes have been reported, the Clinical and Laboratory Standards Institute currently does not recommend a routine detection method for PABLs. The aim of this study is to compare the performances of 3 phenotypic PABL detection methods. METHODS: Total 276 non-duplicated clinical isolates of E. coli (N=97), K. pneumoniae (N=136), and P. mirabilis (N=43) were collected from 14 hospitals in Korea between April and June 2007 in a non-consecutive and non-random manner. Multiplex PCR was performed to detect the PABL genes. Further, 3 phenotypic detection methods-cephamycin-Hodge test, Tris-EDTA (TE) disk test, and combination-disk test with 3-aminophenylboronic acid (BA)-were performed using cefoxitin and cefotetan disks. RESULTS: PABL genes were detected by multiplex PCR in 122/276 isolates, including 14/97 E. coli, 105/136 K. pneumoniae, and 3/43 P. mirabilis isolates. The combination-disk test with BA showed higher sensitivity (98.4%), specificity (92.2%), and efficiency (96.3%) than the cephamycin-Hodge (76.2%, 96.1%, and 88.6%, respectively) and the TE-disk (80.3%, 91.6%, and 87.9%, respectively) tests. CONCLUSIONS: The combination-disk test with BA is a simple, efficient, and interpretable test that can be applicable in clinical laboratories involved in the detection of PABLs in clinical isolates of E. coli, K. pneumoniae, and P. mirabilis.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*analysis ; Cefotetan/pharmacology ; Cefoxitin/pharmacology ; Disk Diffusion Antimicrobial Tests/*methods ; Escherichia coli/genetics/*isolation & purification ; Humans ; Klebsiella pneumoniae/genetics/*isolation & purification ; Phenotype ; Plasmids ; Proteus mirabilis/genetics/*isolation & purification ; Sensitivity and Specificity ; beta-Lactamases/*analysis

Since 2001, ten more OXA-48 variants have been identified. Shewanella spp. has been thought to be the original host for OXA-48-like enzymes. These enzymes strongly hydrolyze penicillins and weakly hydrolyze carbapenems, with very weak activity against broad-spectrum cephalosporins. The OXA-48-like genes are always plasmid-borne and have been located in insertion sequences. OXA-48-like carbapenemases have been identified mainly from Turkey, North African countries, the Middle East, and India. Furthermore, the emergence and outbreak of OXA-48-like producers in Korea have been reported recently. Because some OXA-48-like-producing Enterobacteriaceae isolates do not exhibit resistance to broad-spectrum cephalosporins and only decreased susceptibility to carbapenems, their detection can be difficult. Adequate screening and detection methods are required to prevent and control the dissemination of OXA-48-like-producing Enterobacteriaceae.
Carbapenems ; Cephalosporins ; Enterobacteriaceae* ; India ; Korea ; Mass Screening ; Middle East ; Penicillins ; Shewanella ; Turkey

BACKGROUND: Of the plasmid-mediated AmpC beta-lactamases (ABLs), CMY-2 is the most prevalent and is distributed in many countries. However, little is known about the emergence and characteristics of CMY-2 among Escherichia coli isolates in Korea. The aims of this study were to detect the emergence of the CMY-2 beta-lactamase in clinical isolates of E. coli from various regions in Korea. METHODS: Eighteen cefoxitin non-susceptible isolates of 1, 130 consecutive, nonrepeat isolates of E. coli at five university hospitals were tested for antimicrobial susceptibility by the broth microdilution method. The cefoxitin non-susceptible isolates were further investigated by AmpC disk tests, double disk synergy (DDS) tests, isoelectric focusing, CMY-2-specific PCR, DNA sequencing, and plasmid analysis. RESULTS: Seven (0.6%) isolates of plasmid-mediated ABL-producing E. coli were found at three of the five hospitals; all seven isolates produced CMY-2 beta-lactamase and one of the isolates was also tested positive by the DDS test. All isolates demonstrated different plasmid patterns by plasmid analysis. CONCLUSIONS: Our data indicate that CMY-2-producing E. coli has emerged and is prevalent in the medical institution in Korea. Therefore, constant surveillance is needed to prevent its further spread.
beta-Lactamases ; Cefoxitin ; Escherichia coli* ; Hospitals, University ; Isoelectric Focusing ; Korea ; Plasmids ; Polymerase Chain Reaction ; Sequence Analysis, DNA

PURPOSE: Virulent gene expression in Staphylococcus aureus is controlled by regulators such as the accessory gene regulator (agr). Strains can be divided into four major agr groups (agr I-IV) on the basis of agrD and agrC polymorphisms. The purpose of this study was to define the proportion of agr I, II, and III polymorphisms and to compare the clinical characteristics between group I and non-group I polymorphisms of methicillin-resistant Staphylococcus aureus (MRSA) strains in a Korean tertiary care teaching hospital. MATERIALS AND METHODS: A total of 158 clinical isolates were evaluated by RFLPs (restriction fragment length polymorphisms). RESULTS: The mean age of the patients was 50.2 +/- 21.9 years old. There were 74 (49.3%), 66 (44.0%), 10 (6.7%), 7 (4.4%), and 1 (0.6%) strains in agr group I, II, III, I + II, and I + III polymorphisms, respectively. Only ear infections were a statistically significant clinical parameter according to univariate (p=0.001) and multivariate analysis (OR, 4.721 (1.273-17.508), p=0.020). CONCLUSION: This study suggests that agr group I is the most prevalent in Korea, and ear infections are correlated with the group I polymorphism, which is a different clinical trend from western countries. It can also be inferred that community-acquired MRSA correlates with agr group I.