Comparison of the ASTA MicroIDSys and VITEK MS matrix-assisted laser desorption/ionization time-of-flight mass spectrometry systems for identification of clinical bacteria and yeasts.

The ASTA MicroIDSys system (ASTA, Suwon, Korea) is a newly developed Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) system for identification of microorganisms. We compared the performance of the ASTA MicroIDSys system with that of the VITEK MS system (bioMérieux, Marcy l'Etoile, France) for identifying clinical microorganisms. A total 2055 isolates including 1910 bacteria and 145 yeasts were tested.

Performance of a Novel Fluorogenic Assay for Detection of Carbapenemase-Producing from Bacterial Colonies and Directly from Positive Blood Cultures.

Rapid and accurate detection of carbapenemase-producing (CPE) is critical for appropriate treatment and infection control. We compared a rapid fluorogenic assay using a carbapenem-based fluorogenic probe with other phenotypic assays: modified carbapenem inactivation method (mCIM), Carba NP test (CNP), and carbapenemase inhibition test (CIT). A total of 217 characterized isolates of were included as follows: 63 CPE; 48 non-carbapenemase-producing carbapenem-resistant (non-CP-CRE); 53 extended-spectrum β-lactamase producers; and 53 third-generation-cephalosporin-susceptible isolates.

Clinical usefulness of iQ200/iChem Velocity workstation for screening of urine culture.

Background: Clinical microbiology laboratories are asked to process large numbers of urine specimens for culture, but only 20-40% of them are positive. Therefore, a rapid, reliable screening method is necessary to speed up the reporting of a negative result. In this study, we evaluated the iQ200/iChem workstation, which is a combination of digital imaging software and a strip reader to predict negative urine culture.

Comparative Evaluation of Seegene Allplex Gastrointestinal, Luminex xTAG Gastrointestinal Pathogen Panel, and BD MAX Enteric Assays for Detection of Gastrointestinal Pathogens in Clinical Stool Specimens.

Context.—: Infectious gastroenteritis is caused by various pathogens, including bacteria, viruses, and parasites.

Objective.

Evaluation of modified saponin preparation method for the direct identification and antimicrobial susceptibility testing from positive blood culture.

Background: We evaluated the two in-house sample preparation methods (saponin method (SAP) and [saponin + Sputazyme] method (SSPZ)) for direct identification of microorganisms using MALDI-TOF MS from positive blood culture bottles. Also, we evaluated the [saponin + Sputazyme] method for direct antimicrobial susceptibility testing (AST) using Vitek 2 system.

Methods: For direct identification, 163 prospective, monomicrobial positive blood culture bottles and 25 contrived blood culture bottles spiked with 25 infrequently isolated bacterial strains were included.

Atypical Facial Filler Granuloma: Comparative Histologic Analysis with Paraffinoma.

Dermal fillers are generally accepted as safe and well-tolerable cosmetic tools. However, adverse reactions have been reported in the literature. Here, we present a case of atypical facial filler granuloma and compare its histologic features with those of the classic paraffinoma.

Recurrent Extranodal NK/T-Cell Lymphoma Presenting as a Perforating Palatal Ulcer and Oro-Nasal Fistula.

Nasal-type extranodal natural killer/T-cell lymphoma (ENKTL) is a rare disease presenting with non-specific symptoms, typically originating in the nasal cavity, palate, or midfacial region. Oral cavity is an extremely rare site for this type of lymphoma. In this report, we present a case of palatal perforation and oro-nasal fistula as a manifestation of recurrent ENKTL.

In Vitro Evaluation of Betafoam, a New Polyurethane Foam Dressing.

Background: A new polyurethane foam dressing impregnated with 3% povidone-iodine (Betafoam; Genewell, Seoul, Korea) was recently developed based on the hypothesis that its physical properties, including improved moisture-retention capacity and antimicrobial activity, are at least as good as those achieved with the current foam dressings that contain silver, but also associated with reduced cost and cytotoxicity to host cells. The purpose of this in vitro study was to evaluate the efficacy of Betafoam by comparing its physical properties, antimicrobial activity, and cytotoxicity with those of 3 silver foam dressings (Allevyn-Ag [Smith & Nephew, Hull, United Kingdom]; Mepilex-Ag [Mölnlycke Health Care, Gothenburg, Sweden]; and PolyMem-Ag [Ferris MFG Corp, Burr Ridge, Illinois]) used worldwide.

Methods: This study measured each dressing's pore size, fluid absorption time, fluid absorption capacity, fluid retention capacity, antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa, and cytotoxicity to mouse fibroblasts.

Evaluation of BD MAX Staph SR Assay for Differentiating Between Staphylococcus aureus and Coagulase-Negative Staphylococci and Determining Methicillin Resistance Directly From Positive Blood Cultures.

Background: We evaluated the performance of the BD MAX StaphSR Assay (SR assay; BD, USA) for direct detection of Staphylococcus aureus and methicillin resistance not only in S. aureus but also in coagulase-negative Staphylococci (CNS) from positive blood cultures.

Methods: From 228 blood culture bottles, 103 S.

Performance of a novel fluorogenic chimeric analog for the detection of third-generation cephalosporin resistant bacteria.

Resistance to third generation cephalosporins is widely disseminated in Enterobacteriaceae mainly due to extended-spectrum-β-lactamases, plasmid AmpC β-lactamases, and hyperproduction of chromosomal AmpC β-lactamases. Here we evaluated the performance of a novel fluorogenic probe rapid test and compared the results with the phenol red assay using a total of 77 characterized organisms (44 extended-spectrum-β-lactamases, 33 chromosomal or plasmid AmpC β-lactamases) and 46 susceptible organisms. The fluorescent assay showed higher sensitivity than the phenol red assay in cefotaximase type extended-spectrum-β-lactamases, non- cefotaximase type extended-spectrum-β-lactamases, chromosomal AmpC β-lactamases, and plasmid AmpC β-lactamases (96.

Direct Identification and Antimicrobial Susceptibility Testing of Bacteria From Positive Blood Culture Bottles by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry and the Vitek 2 System.

Background: We evaluated the reliability and accuracy of the combined use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) bacterial identification and Vitek 2 antimicrobial susceptibility testing (AST) for bacteria from positive blood culture bottles.

Methods: Direct identification and AST were performed in parallel to the standard methods in monomicrobial positive blood culture bottles. In total, 254 isolates grown on aerobic and/or anaerobic bottles were identified with MALDI-TOF Vitek MS (bioMérieux, France), and 1,978 microorganism/antimicrobial agent combinations were assessed.

Effects of Panax ginseng extract on human dermal fibroblast proliferation and collagen synthesis.

Current studies of Panax ginseng (or Korean ginseng) have demonstrated that it has various biological effects, including angiogenesis, immunostimulation, antimicrobial and anti-inflammatory effects. Therefore, we hypothesised that P. ginseng may also play an important role in wound healing.

Genotypes of Ciprofloxacin-Resistant Klebsiella pneumoniae in Korea and Their Characteristics According to the Genetic Lineages.

We investigated the molecular genotypes of ciprofloxacin-resistant Klebsiella pneumoniae and their characteristics according to the genetic lineages. For 160 K. pneumoniae collected in 2013, ciprofloxacin minimum inhibitory concentrations (MICs) were determined by agar dilution method.

Direct Identification of Urinary Tract Pathogens From Urine Samples Using the Vitek MS System Based on Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry.

Background: We evaluated the coincidence rate between Vitek MS system (bioMérieux, France) and Vitek 2 in identifying uropathogens directly from urine specimens.

Methods: Urine specimens submitted to our microbiology laboratory between July and September 2013 for Gram staining and bacterial culture were analyzed. Bacterial identification was performed by using the conventional method.

Evaluation of 3 automated real-time PCR (Xpert C. difficile assay, BD MAX Cdiff, and IMDx C. difficile for Abbott m2000 assay) for detecting Clostridium difficile toxin gene compared to toxigenic culture in stool specimens.

We evaluated the performance of the 3 automated systems (Cepheid Xpert, BD MAX, and IMDx C. difficile for Abbott m2000) detecting Clostridium difficile toxin gene compared to toxigenic culture. Of the 254 stool specimens tested, 87 (48 slight, 35 moderate, and 4 heavy growth) were toxigenic culture positive.

Rapid detection of Gram-negative bacteria and their drug resistance genes from positive blood cultures using an automated microarray assay.

We evaluated the performance of the Verigene Gram-negative blood culture (BC-GN) assay (CE-IVD version) for identification of Gram-negative (GN) bacteria and detection of resistance genes. A total of 163 GN organisms (72 characterized strains and 91 clinical isolates from 86 patients) were tested; among the clinical isolates, 86 (94.5%) isolates were included in the BC-GN panel.

Performance of chromID Clostridium difficile agar compared with BBL C. difficile selective agar for detection of C. difficile in stool specimens.

We evaluated the performance of a new chromogenic medium for detection of Clostridium difficile, chromID C. difficile agar (CDIF; bioMérieux, France), by comparison with BBL C. difficile Selective Agar (CDSA; Becton Dickinson and Company, USA).

Risk factors for mortality in patients with Pseudomonas aeruginosa bacteremia; retrospective study of impact of combination antimicrobial therapy.

Background: Whether the combination of antimicrobial therapy is a factor in mortality in Pseudomonas aeruginosa bacteremia remains to be elucidated. This study investigated the risk factors for mortality in P. aeruginosa bacteremia patients and the influence of adequate antimicrobial therapy and combination therapy on clinical outcomes.

Assessment of the quantitative ability of AdvanSure TB/NTM real-time PCR in respiratory specimens by comparison with phenotypic methods.

Accurate quantification of mycobacterial load is important to evaluate disease severity and to monitor the course of treatment in tuberculosis (TB). We evaluated the quantitative capability of the AdvanSure TB/NTM real-time PCR kit (LG Life Science, Korea) to determine the cycle threshold (Ct) for mycobacterial burden. We retrospectively analyzed data from 108 patients whose respiratory specimens (sputums and bronchoalveolar lavage fluids) were positive for Mycobacterium tuberculosis complex (85 culture-positive and 23 culture-negative specimens).

Rates of fecal transmission of extended-spectrum β-lactamase-producing and carbapenem-resistant Enterobacteriaceae among patients in intensive care units in Korea.

Background: We investigated the rates of fecal transmission of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) and carbapenem-resistant Enterobacteriaceae (CRE) among patients admitted to intensive care units (ICUs).

Methods: From June to August 2012, rectal cultures were acquired from all patients at ICU admission. For patients not carrying ESBL-E or CRE at admission, follow-up cultures were performed to detect acquisition.

Comparative evaluation of three chromogenic media combined with broth enrichment and the real-time PCR-based Xpert MRSA assay for screening of methicillin-resistant Staphylococcus aureus in nasal swabs.

Background: We evaluated the performance of three chromogenic media (Brilliance agar I [Oxoid, UK], Brilliance agar II [Oxoid], and ChromID MRSA [Biomérieux, France]) combined with broth enrichment and the Xpert MRSA assay for screening of methicillin-resistant Staphylococcus aureus (MRSA).

Methods: We obtained 401 pairs of duplicate nasal swabs from 321 patients. One swab was suspended overnight in tryptic soy broth; 50-µL aliquots of suspension were inoculated on the three chromogenic media.

Evaluation of MicroScan WalkAway and Vitek 2 for determination of the susceptibility of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates to cefepime, cefotaxime and ceftazidime.

Objectives: The aim of this study was to evaluate the accuracies of these automated susceptibility test systems with cefepime, cefotaxime and ceftazidime using the new CLSI and EUCAST guidelines in extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae.

Methods: A total of 220 ESBL-producing clinical isolates were collected from 12 hospitals in Korea. Susceptibility testing for cefepime, cefotaxime and ceftazidime was performed by MicroScan WalkAway, Vitek 2 and the CLSI broth microdilution test.

Prevalence and contributing factors of nonsusceptibility to imipenem or meropenem in extended-spectrum β-lactamase-producing Klebsiella pneumoniae and Escherichia coli.

Among the extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae and Escherichia coli, 3.9% of K. pneumoniae showed nonsusceptibility to imipenem or meropenem; and their mechanism was the combination of ESBL and/or plasmid-mediated AmpC β-lactamase production and porin loss.

Evaluation of Vitek2 and BD Phoenix in antimicrobial susceptibility testing of Acinetobacter baumannii and Pseudomonas aeruginosa.

The accuracy of antimicrobial susceptibility testing of Vitek2 and BD Phoenix against Acinetobacter baumannii and Pseudomonas aeruginosa was evaluated. Both systems showed overall categoric agreement of < or =90% for cefepime and ceftazidime against A. baumannii and imipenem and cefepime (and ceftazidime with Vitek2) against P.