Impact of national pneumococcal vaccination program on invasive pneumococcal diseases in South Korea.

Following the introduction of pneumococcal conjugate vaccines (PCVs), the rate of invasive pneumococcal disease (IPD) declined, however, IPDs replaced by serotypes that are not included in the vaccine have emerged. We describe the epidemiology of IPD in South Korea over a 4.5-year period, encompassing the impact following introduction of PCV10/13 and PPSV23 into the public immunization program, and assess serotype dynamics in pediatric and adult population.

The SAV1322 gene from Staphylococcus aureus: genomic and proteomic approaches to identification and characterization of gene function.

Background: Bacterial two-component regulatory systems (TCRS) are associated with the expression of virulence factors and antibiotic susceptibility. In Staphylococcus aureus, 16 TCRS types have been identified. The histidine kinase/response regulator SAV1321/SAV1322 in the S.

Draft Genome Sequences of Vancomycin-Intermediate Staphylococcus aureus Strains in South Korea.

We report here the draft genome sequences of four vancomycin-intermediate Staphylococcus aureus (VISA) strains from South Korean hospitals participating in a nationwide laboratory surveillance program for vancomycin-intermediate and vancomycin-resistant Staphylococcus aureus All strains harbor mutations in the walKR, graSR, and/or rpoB genes that are known frequently mutated determinants of VISA.

Small-Colony Variants in Persistent and Recurrent Staphylococcus aureus Bacteremia.

The small-colony variant (SCV) phenotype of Staphylococcus aureus is associated with intracellular persistence and reduced antimicrobial susceptibility, which can lead to therapeutic failure. Since SCVs grow slowly and have a confusing morphology, the identification of infections due to SCV is difficult. We have identified SCVs in two patients who presented with persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia complicated by surgical site infections after cardiothoracic surgery.

Structure and transfer of the vanA cluster in vanA-positive, vancomycin-susceptible Enterococcus faecium, and its revertant mutant.

Of 18 vanA-positive vancomycin-susceptible Enterococcus faecium isolates, vanRS in the vanA cluster was detected in all isolates, while vanHAX was detected in only 2 isolates. Following exposure to glycopeptides, 22.2% of vancomycin-susceptible E.

Proteomic Analysis of Intracellular and Membrane Proteins From Voriconazole-Resistant Candida glabrata.

Objectives: The proteomic analysis of voriconazole resistant Candida glabrata strain has not yet been investigated. In this study, differentially expressed proteins of intracellular and membrane fraction from voriconazole-susceptible, susceptible dose-dependent (S-DD), resistant C. glabrata strains were compared with each other and several proteins were identified.

Investigation of Biofilm Formation and its Association with the Molecular and Clinical Characteristics of Methicillin-resistant Staphylococcus aureus.

Objectives: To investigate the biofilm-forming related factors against MRSA bloodstream isolates and evaluates their clinical features and treatment outcomes by biofilm production.

Methods: We collected 126 consecutive methicillin-resistant Staphylococcus aureus (MRSA) causing blood stream infections (BSIs) at 10 tertiary hospitals from 2007 to 2009. We investigated biofilm-forming ability using a microtiter plate assay, and molecular characteristics including multilocus sequence typing, staphylococcal cassette chromosome mec and accessory gene regulator types.

Detection of clonal KPC-2-producing Klebsiella pneumoniae ST258 in Korea during nationwide surveillance in 2011.

This study analysed the characteristics and genetic similarity of recent Klebsiella pneumoniae carbapenemase (KPC-2)-producing Klebsiella pneumoniae isolates from Korea. Recent laboratory surveillance detected an increase in carbapenemase-producing Enterobacteriaceae in Korea. A total of 6 KPC-2-producing K.

Prevalence of amino acid changes in the yvqF, vraSR, graSR, and tcaRAB genes from vancomycin intermediate resistant Staphylococcus aureus.

Vancomycin intermediate Staphylococcus aureus (VISA) strains are increasingly prevalent in the hospital setting, and are of major concern in the treatment of methicillin-resistant S. aureus infections. Multiple mutations in vancomycin-susceptible S.

Evaluation of MGIT 960 System for the Second-Line Drugs Susceptibility Testing of Mycobacterium tuberculosis.

Many laboratories validate DST of the second-line drugs by BACTEC MGIT 960 system. The objective of this study is to evaluate the critical concentration and perform DST for the 2nd line drugs. We evaluated 193 clinical strains of M.

Molecular and epidemiological characterization of carbapenem-resistant Acinetobacter baumannii in non-tertiary Korean hospitals.

Purpose: The increasing prevalence and global spread of carbapenem-resistant Acinetobacter baumannii (A. baumannii) has become a serious problem. The aim of this study was to investigate molecular and epidemiological characteristics of carbapenem-resistant A.

Autolytic activity and molecular characteristics of Staphylococcus haemolyticus strains with induced vancomycin resistance.

The aim of this study was to investigate the molecular characteristics of induced vancomycin resistance in Staphylococcus haemolyticus. Autolytic properties and phenotypic characteristics of passage-selected vancomycin-resistant S. haemolyticus strains were examined.

Proteomic Analysis of Cellular and Membrane Proteins in Fluconazole-Resistant Candida glabrata.

Objectives: Candida glabrata is one of the most common causes of Candida bloodstream infections worldwide. Some isolates of C glabrata may be intermediately resistant to azoles, with some strains developing resistance during therapy or prophylaxis with fluconazole. In this study, we used a proteomic approach to identify differentially expressed proteins between fluconazoleresistant and -susceptible strains.

Comparison of genetic epidemiology of vancomycin-resistant Enterococcus faecium isolates from humans and poultry.

This study was conducted to investigate the molecular characteristics and genetic relatedness of vancomycin-resistant Enterococcus faecium (VREF) isolates obtained from humans and poultry in Korea. A total of 147 VREF isolates from humans (71 clinical isolates) and poultry (76 isolates) in Korea were compared with respect to their antibiotic susceptibilities, organization of the Tn1546 transposon element, detection of virulence genes (esp and hyl), pulsed-field gel electrophoresis (PFGE) typing and multilocus sequence typing (MLST). All of the human and poultry isolates had the vanA gene and 11.

Dissemination of genetically related IMP-6-producing multidrug-resistant Pseudomonas aeruginosa ST235 in South Korea.

The present study aimed to describe the prevalence and molecular epidemiology of metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa isolates obtained from non-tertiary care hospitals and geriatric hospitals in South Korea. Of the 644 isolates, 224 were carbapenem-resistant, amongst which 41 (18.3%) were MBL-producers and the major MBL type was IMP-6 (35 isolates).

Alterations of gyrA, gyrB, and parC and Activity of Efflux Pump in Fluoroquinolone-resistant Acinetobacter baumannii.

Objectives: This study investigated the fluoroquinolone-resistant mechanism of 56 clinical cases of A baumannii infection from 23 non-tertiary hospitals, collected between 2004 and 2006.

Methods: Susceptibility testing was performed by broth microdilution and Epsilometer test. Analyses of quinolone resistance-determining region (QRDR) were done by sequencing.

Downregulation of RNAIII in vancomycin-intermediate Staphylococcus aureus strains regardless of the presence of agr mutation.

Reduced vancomycin susceptibility in Staphylococcus aureus can cause serious problems relating to treatment failure and persistent infection. We investigated vancomycin susceptibility, genetic relationships and transcriptional changes of the accessory gene regulator (agr) in vancomycin-intermediate S. aureus (VISA) strains isolated from South Korea compared with vancomycin-susceptible S.

Gene Expression and Identification Related to Fluconazole Resistance of Candida glabrata Strains.

Objectives: Candida glabrata has become one of the most common causes of Candida bloodstream infections worldwide. Some strains of C. glabrata may be intermediately resistant to all azoles.

Characterization of two newly identified genes, vgaD and vatH, [corrected] conferring resistance to streptogramin A in Enterococcus faecium.

We characterized two new streptogramin A resistance genes from quinupristin-dalfopristin-resistant Enterococcus faecium JS79, which was selected from 79 E. faecium isolates lacking known genes encoding streptogramin A acetyltransferase. A 5,650-bp fragment of HindIII-digested plasmid DNA from E.

High prevalence of extended-spectrum beta-lactamases and plasmid-mediated AmpC beta-lactamases in Enterobacteriaceae isolated from long-term care facilities in Korea.

The aim of this study was to investigate for the first time the prevalence and types of extended-spectrum beta-lactamase (ESBL) and plasmid-mediated AmpC beta-lactamase (PABL) in Enterobacteriaceae in Korean long-term care facilities (LTCFs). ESBL rates were 45.3% (72/159) in Escherichia coli and 42.

Restriction fragment length polymorphism (RFLP) patterns and sequence analysis of high-level mupirocin-resistant meticillin-resistant staphylococci.

High-level mupirocin resistance results from the acquisition of a mupirocin resistance (Mupr) plasmid carrying the mupA gene. In this study, we investigated the heterogeneous location of the mupA gene as well as sequence variations in mupA restriction fragment length polymorphism (RFLP) types of high-level mupirocin-resistant (MuH) staphylococci isolated from tertiary hospitals and long-term care facilities in South Korea. RFLP patterns of the mupA gene were investigated in 14 MuH staphylococci isolates, and sequence variations of the cassette-like construction composed of the transfer gene complex (trs), an insertion sequence (IS257-like) and the mupA gene of the Mupr plasmid were also studied.

Investigation of Klebsiella pneumoniae isolates producing SHV-12 and SHV-11 beta-lactamases in Korean hospitals.

Of 143 clinical isolates of Klebsiella pneumoniae collected from Korean non-tertiary hospitals, 24 (16.8%) showed an extended-spectrum beta-lactamase-positive phenotype. PCR and sequence analysis revealed the presence of TEM-116 (n=13), CTX-M-3 (n=5), CTX-M-14 (n=2), CTX-M-15 (n=3), and SHV-12 (n=16).

National surveillance of antifungal susceptibility of Candida species in South Korean hospitals.

We investigated the species distribution and antifungal susceptibility of Candida isolates from tertiary and non-tertiary hospitals in South Korea from 2002-2004. Of the 612 Candida isolates that were collected, Candida albicans, C. parapsilosis, C.