Serotyping and antimicrobial susceptibility of Salmonella spp.: nationwide multicenter study in Korea.

The study aimed to investigate the prevalence of various serotypes and extended-spectrum β-lactamase-producing features of Salmonella strains and to determine the antimicrobial susceptibility of 256 Salmonella strains other than Salmonella serotype Typhi, which were isolated at 12 university hospitals in Korea. We identified 46 serotypes of Salmonella spp. Serogroup D was the most common (39.

Evaluation of DNA extraction methods and their clinical application for direct detection of causative bacteria in continuous ambulatory peritoneal dialysis culture fluids from patients with peritonitis by using broad-range PCR.

Background: The aims of this study were to compare several DNA extraction methods and 16S rDNA primers and to evaluate the clinical utility of broad-range PCR in continuous ambulatory peritoneal dialysis (CAPD) culture fluids.

Methods: Six type strains were used as model organisms in dilutions from 10(8) to 10(0) colony-forming units (CFU)/mL for the evaluation of 5 DNA extraction methods and 5 PCR primer pairs. Broad-range PCR was applied to 100 CAPD culture fluids, and the results were compared with conventional culture results.

Prevalence of plasmid-mediated quinolone resistance and its association with extended-spectrum beta-lactamase and AmpC beta-lactamase in Enterobacteriaceae.

Background: We investigated the prevalence of plasmid-mediated quinolone resistance and its association with extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase in Enterobacteriaceae.

Methods: A total of 347 non-duplicated isolates of Enterobacteriaceae were collected between August and October 2006 from 2 hospitals. Qnr determinant screening was conducted using PCR amplification, and all positive results were confirmed by direct sequencing.

Prevalence of plasmid-mediated quinolone resistance and mutations in the gyrase and topoisomerase IV genes in Salmonella isolated from 12 tertiary-care hospitals in Korea.

Background: The aim of this study was to investigate the prevalence of plasmid-mediated quinolone resistance (PMQR) and mutations in quinolone resistance-determining regions (QRDRs) of Salmonella and their association with fluoroquinolone susceptibility in Korea.

Methods: A total of 284 nonduplicated clinical isolates of Salmonella were collected from various clinical specimens at 12 tertiary-care hospitals in Korea. The qnrA, qnrB, and qnrS genes were detected by multiplex polymerase chain reaction (PCR).

Fecal colonization of Enterobacteriaceae carrying plasmid-mediated quinolone resistance determinants in Korea.

The aims of the current study were to investigate the prevalence and molecular characteristics of plasmid-mediated quinolone resistance (PMQR) genes from colonizing fecal organisms and to compare the incidence and subtype of these genes according to bacterial species and hospital at five tertiary-care hospitals in Korea. A total of 500 nonduplicated clinical isolates of Enterobacteriaceae were obtained from fecal specimens at five tertiary-care hospitals between March and May 2008. The PMQR genes (qnrA, qnrB, qnrS, aac(6')-Ib-cr, and qepA) were amplified by PCR and confirmed by direct sequencing of the PCR products.

Identification of coagulase-negative staphylococci isolated from continuous ambulatory peritoneal dialysis fluid using 16S ribosomal RNA, tuf, and SodA gene sequencing.

Introduction: Coagulase-negative staphylococcus (CoNS) is the most common pathogen in continuous ambulatory peritoneal dialysis (CAPD)-associated peritonitis. There is no well-organized, standardized database for CoNS, and few studies have used gene sequencing in reporting species distribution in CAPD peritonitis. In the present study, we used 3 housekeeping genes to evaluate the prevalence of CoNS isolated from CAPD peritonitis episodes and to estimate the accuracy of, and the characteristic differences between, these genes for species identification.

The optimal wavelength of spectrophotometric broth microdilution antifungal susceptibility test for flucytosine and three azoles.

Background: There is no guideline for the appropriate wavelength at which to measure the optical density (OD) value in broth microdilution antifungal susceptibility testing, although a spectrophotometric reading method is commonly used. The present study aimed to analyze the difference in the OD values over the range of visible light and to ascertain the optimal wavelength for the spectrophotometric method of microdilution testing.

Methods: We measured the OD of background blank controls of broth medium, antifungal agents, and inocula of five type strains using a Synergy HT multi-detection microplate reader at 5-nm intervals from 380 nm to 760 nm.

Two cases of peritonitis caused by Kocuria marina in patients undergoing continuous ambulatory peritoneal dialysis.

Kocuria spp. are members of the Micrococcaceae family that are frequently found in the environment and on human skin. Few human infections have been reported.

Inhibitory effect of anethole on T-lymphocyte proliferation and interleukin-2 production through down-regulation of the NF-AT and AP-1.

Anethole is a naturally occurring alkenylbenzene found in a variety of foods and essential oils. In the present study, we investigated the effect of anethole on T-cell function and the regulatory mechanism of its effect. Direct addition of anethole to B6C3F1 mouse splenocyte cultures produced a concentration-dependent inhibition of the lymphoproliferative response to concanavalin A stimulation.

Cloning of the large subunit of replication protein A (RPA) from yeast Saccharomyces cerevisiae and its DNA binding activity through redox potential.

Eukaryotic replication protein A (RPA) is a single-stranded(ss) DNA binding protein with multiple functions in DNA replication, repair, and genetic recombination. The 70-kDa subunit of eukaryotic RPA contains a conserved four cysteine-type zinc-finger motif that has been implicated in the regulation of DNA replication and repair. Recently, we described a novel function for the zinc-finger motif in the regulation of human RPA's ssDNA binding activity through reduction-oxidation (redox).