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The platform model of business has allowed peer-to-peer interactions that expand the universe of opportunity for providers and users of goods and services. In addition to the numerous benefits of the platform model, it has been fraught with its share of unanticipated challenges to consumer equality – a critical measure of the social welfare. Grounded in the Power-Responsibility Equilibrium framework, this study examines the most aggressive form of consumer action, filing a lawsuit against the platform company, in response to discrimination experienced by consumers on the platform. An analysis of the five legal cases brought by consumers against Roommates.com, Airbnb, and Uber highlights how current laws may be ineffective in addressing the problem of discrimination in the online marketplace against members of protected categories such as race, sexual orientation, and disability. We provide implications for platform companies and public policy makers for changes to promote equality in the sharing economy.

Herein, we introduce a smartphone-integrated immunosensor based on non-spectroscopic optical detection. Sedimentation of the retroreflector and gentle inversion of the microfluidic chip was chosen as biosensing principles to ensure minimal human involvement. To realize this, wash-free immunosensing was implemented on a polymeric microfluidic chip device fabricated for light signal penetration in retroreflection signal acquisition. Applying a transparent chip and passive modulation of retroreflectors enabled the minimization of human error during sensing. In addition, a retroreflection-detectable optical gadget was constructed for integration with the commercial smartphone. The gadget had an optical chamber that induced retroreflection by integration with a smartphone. When the micro-sized reflector, named the retroreflective Janus microparticle, reacted on the sensing surface, the incident light was retroreflected towards the image sensor and quantified by a smartphone-installed Android application package. The developed application package features include time-lapse image capture performed by manipulating LED flash and camera modules, and quantification of retroreflected signal counts by image processing of time-lapse images. With this platform, the user could independently commence optical signal processing without a complicated optical setup and running software on a PC, and sensitive and reproducible immunosensing results could be obtained. The applicability test for creatine kinase-myocardial band detection from the buffer to serum was conducted and presented a calibration curve of 0–1000 ng/mL within 1 h. With the developed system, we believe that the applicability of the platform in bioanalytical detection can be expanded.

Background The recent molecular epidemiology of ESBL-producing Escherichia coli infection in two Korean community hospitals was evaluated in this prospective observational study. Methods We collected non-duplicated E. coli isolates from consecutive, sequentially encountered patients with community-onset episodes between March and April 2016 in two community hospitals in Gyeonggi-do province, Korea. We studied the prevalence, clinical characteristics and molecular epidemiology of E. coli sequence type 131 (ST131) isolated from the community. Results From a total of 213 E. coli isolates collected from the community, 94 (44.1%) were community-onset healthcare-associated isolates and 119 (55.9%) were community-associated isolates, of which urinary tract infection was the majority. A total of 55 (25.8%) of the 213 E. coli isolates were confirmed to have ESBL genes, which were mainly CTX-M types such as CTX-M-14 and CTX-M-15. There was no difference in the proportion of globally epidemic ST131 clones or that of O25, O16, H30 , or H30Rx subclones between community-associated and community-onset healthcare-associated isolates. Conclusions In this study, considerable ST131 E. coli isolations in the community were observed and about half of them were related to the history of a visit to the healthcare facilities, indicating the spread of multidrug-resistant E. coli to the community via healthcare facilities.

Summary Background For all countries, information on pathogens causing healthcare-associated infections is important in order to develop proper strategies for preventing and treating nosocomial infections. Aim To assess the change in frequencies and antimicrobial resistance of pathogens causing device-associated infections (DAIs) in intensive care units (ICUs) in South Korea between July 2006 and June 2014. Methods Data from the Korean Nosocomial Infections Surveillance System (KONIS) were analysed, including three major DAI types in ICUs. Findings The frequency of Gram-negative bacteria gradually increased for central line-associated bloodstream infection (CLABSI) and ventilator-associated pneumonia (VAP) (from 24.6% to 32.6% and from 52.8% to 73.5%, respectively). By contrast, the frequency of Gram-positive bacteria decreased from 58.6% to 49.2% for CLABSI, and from 44.3% to 23.8% for VAP ( P Staphylococcus aureus was the most frequent causative pathogen in CLABSI throughout the surveillance period, but for VAP was replaced as the most frequent pathogen by Acinetobacter baumannii as of 2010. Candida albicans was the most frequent pathogen for catheter-associated urinary tract infection. The meticillin resistance rate in S. aureus decreased from 95% to 90.2% ( P Klebsiella pneumoniae and Escherichia coli decreased from 43.8% to 14.7% and from 15.0% to 1.8%, respectively ( P A. baumannii increased from 52.9% to 89.8% ( P Conclusion The proportion of Gram-negative bacteria as nosocomial pathogens for CLABSI and VAP has increased. The prevalence of A. baumannii causing DAIs in Korean ICUs has increased rapidly, as has the rate of carbapenem resistance in these bacteria.

In this study, we determined the in vitro activity of various combinations of antimicrobial agents against 54 Neisseria gonorrhoeae isolates. The combined activity of ceftriaxone (CRO) and azithromycin (AZM), CRO and doxycycline (DOX), CRO and spectinomycin (SPT), cefixime (CFX) and AZM, CFX and DOX, and CFX and SPT was determined using a checkerboard method. The fractional inhibitory concentration index (FICI) values for all combinations were either additive or indifferent, and no synergistic or antagonistic effects were found. The FICI comparison in each combination did not show any difference according to the N.gonorrhoeae-resistant phenotypes and genotypic characteristics, including penicillinase-producing N. gonorrhoeae, tetracycline-resistant N. gonorrhoeae, stratified MIC of all antibiotics, and N. gonorrhoeae multiantigen sequence typing. MIC50 and MIC90 of tigecycline by agar dilution were 0.5 mg/L and 0.5 mg/L, respectively, which were lower than that of tetracycline and DOX. Additive/indifference results could suggest that combinations that include CRO may be used safely without a significant likelihood of generating resistance.

The effectiveness of continuous nationwide surveillance on healthcare-associated infections should be investigated in each country.To assess the rate of device-associated infections (DAIs) in intensive care units (ICUs) since the establishment of the Korean Nosocomial Infections Surveillance System (KONIS).Nationwide data were obtained on the incidence rate of DAI in ICUs reported to KONIS by all participating hospitals. The three major DAIs were studied: ventilator-associated pneumonia (VAP), central line-associated bloodstream infection (CABSI), and catheter-associated urinary tract infection (CAUTI). The pooled and year-wise incidence rates (cases per 1000 device-days) of these DAIs were determined for the period 2006 and 2012. In addition, data from institutions that had participated in KONIS for at least three consecutive years were analysed separately.The number of ICUs participating in KONIS gradually increased from 76 in 2006 to 162 in 2012. Between 2006 and 2012, the incidence rate per 1000 device-days for VAP decreased significantly from 3.48 to 1.64 (F = 11, P0.01), for CAUTI the rate decreased non-significantly from 1.85 to 1.26 (F = 2.02, P = 0.07), and for CABSI the rate also decreased non-significantly from 3.4 to 2.57 (F = 1.73, P = 0.12). In the 132 ICUs that had participated in KONIS for at least three consecutive years, the VAP rate significantly decreased from the first year to third year (F = 20.57, P0.01), but the rates of CAUTI (F = 1.06, P = 0.35) and CABSI (F = 1.39, P = 0.25) did not change significantly.The decreased incidence rate of VAP in ICUs in Korea might be associated with the continuous prospective surveillance provided by KONIS.

The incidence of carbapenem-resistant Pseudomonas aeruginosa (CRPA) bacteremia has increased in recent years, and infections caused by CRPA result in higher mortality than those caused by susceptible strains. This study was performed to evaluate the risk factors for mortality and to study the impact of virulence factors and bacterial strains on clinical outcomes in patients with CRPA bacteremia. Data on 63 episodes of CRPA bacteremia that have occurred between January 1, 2007, and December 31, 2009, in a teaching hospital (2000 beds) in Seoul, Korea, were analyzed. The Acute Physiology and Chronic Health Evaluation II (APACHE II) score at the time of CRPA bacteremia and the capacity of CRPA to form biofilm were independent predictive factors for mortality in patients with CRPA bacteremia. In addition, the biofilm-forming ability and elastase activity of strains were correlated with APACHE II scores to measure the severity of disease and estimate predicted mortality in the patients.

This study was performed to investigate the prevalence and molecular epidemiology of Pseudomonas aeruginosa isolates from Korea that produce enzymes with extended-spectrum (ES) activity to β-lactams. A total of 205 non-duplicate P. aeruginosa clinical isolates were collected from 18 university hospitals in Korea. PCR and sequencing experiments were performed to identify genes encoding β-lactamases. PCR mapping and sequencing of the regions surrounding the β-lactamase genes were performed. Multilocus sequence typing experiments were performed. The most common sequence type (ST) was ST235 (n = 96), and 2 single-locus variants of ST235, ST1015 (n = 1) and ST1162 (n = 1), were also identified. These 3 STs were grouped as a clonal complex (CC), CC235. The remaining 107 isolates were identified as 59 different STs. Isolates belonging to CC235 showed higher rates of non-susceptibility to imipenem (85.4% versus 47.7%) and meropenem (92.7% versus 52.3%) compared to non-CC235 isolates. All the metallo-β-lactamase (MBL)–producing isolates were identified as CC235, except for 1 ST591. Genes encoding OXA-17 and OXA-142 were detected in 1 isolate and 4 isolates of CC235, respectively; while the bla SHV-12 gene was detected in 4 non-CC235 isolates. Class A and D β-lactamases with ES activity play a role in acquiring ceftazidime resistance in P. aeruginosa in Korea. Production of IMP-6 and VIM-2 MBLs is the main mechanisms in acquiring resistance to ceftazidime and carbapenems in P. aeruginosa isolates in Korea. Clonal spread of P. aeruginosa CC235 may be an important conduit for the dissemination of MBL genes in Korea.

Wound healing, angiogenesis, and hair follicle maintenance are often impaired in the skin of diabetic patients, but the pathogenesis has not been well understood. Here, we report that circulation levels of kallistatin, a member of the serine proteinase inhibitor (SERPIN) superfamily with antiangiogenic activities, were elevated in type 2 diabetic patients with diabetic vascular complications. To test the hypothesis that elevated kallistatin levels could contribute to a wound-healing deficiency via the inhibition of Wnt/β-catenin signaling, we generated kallistatin-transgenic (KS-TG) mice. KS-TG mice had reduced cutaneous hair-follicle density, microvascular density, and panniculus adiposus layer thickness, as well as altered skin microvascular hemodynamics and delayed cutaneous wound healing. Using Wnt reporter mice, our results showed that Wnt/β-catenin signaling is suppressed in the dermal endothelium and hair follicles in KS-TG mice. Lithium, a known activator of β-catenin via inhibition of glycogen synthase kinase-3β, reversed the inhibition of Wnt/β-catenin signaling by kallistatin and rescued the wound-healing deficiency in KS-TG mice. These observations suggest that elevated circulating antiangiogenic serpins in diabetic patients may contribute to impaired wound healing through inhibition of Wnt/β-catenin signaling. Activation of Wnt/β-catenin signaling, at a level downstream of Wnt receptors, may ameliorate the wound-healing deficiency in diabetic patients.

Background Methicillin-resistant Staphylococcus aureus (MRSA) infections are a concern across the worldwide. Methods Antibiotic stewardship and hand hygiene programs were reinforced in a 2,000-bed tertiary hospital in South Korea where the methicillin resistance rate of Staphylococcus aureus is about 65%. The computerized prescription restriction was implemented in August 2008. "Hand hygiene program," consistent with World Health Organization guideline, was reinforced in December 2008. We assessed the effect of the infection control programs on the incidence of MRSA bloodstream infection (BSI) from January 2006 through November 2011. Results Incidence of MRSA BSI was reduced from 0.171 per 1,000 patient-days in 2009 to 0.116 per 1,000 patient-days in 2011 ( P = .009). Monthly mean antibiotic consumption decreased from 690.54 ± 28.33 defined daily dose per 1,000 patients-days in 2008 to 652.47 ± 20.77 ( P = .015) in 2011. The rates of performance in hand hygiene increased from 43% in 2008 to 83% in 2011 ( P = .043). Conclusion Although we did not implement all components of "MRSA bundle," efforts to reinforce antibiotic stewardship and hand hygiene program for 3 years had beneficial effects on the decrease in MRSA BSI in this institute with high rate of MRSA.

In this study, we determined the prevalence of mupirocin and antiseptics resistance in methicillin-resistant Staphylococcus aureus (MRSA) at a secondary- and a tertiary-care hospital in Korea. Mupirocin susceptibility test, ileS gene sequencing, and polymerase chain reaction for mupA, qacA/B, and smr gene were performed with 456 nonduplicated MRSA isolates collected from 2 hospitals in Korea. Genetic relatedness was determined by spa typing and multilocus sequence typing (MLST). The rates of low-level and high-level mupirocin resistance were 7% and 2% in the secondary-care hospital and 17% and 2% in the tertiary-care hospital, respectively. The positive rate of qacA/B and smr gene in mupirocin-resistant MRSA was 65% and 71%, respectively. In spa typing, most mupirocin-resistant MRSA showed genetic relatedness and some of the highly resistant isolates were ST239 and ST5 in MLST analysis. The distribution of low-level and high-level mupirocin resistance and the coexistence of antiseptic resistance in MRSA can result in failure of decolonization in Korea.

This study was performed to investigate the prevalence of rectal colonization with multidrug-resistant Escherichia coli in dogs hospitalized at veterinary hospitals in Korea and to assess the molecular epidemiologic traits of this organism. A total of 63 unique E. coli isolates obtained from the rectal swabs of hospitalized dogs were analyzed. Genes encoding CTX-M extended-spectrum β-lactamases (ESBLs) and AmpC enzymes were detected in 21 (33.3%) and 15 (23.8%) canine E. coli isolates, respectively. Twelve canine E. coli isolates harbored both the genes encoding the CTX-M and AmpC enzymes. Six ESBL-producing E. coli isolates also carried the rmtB gene. All 24 E. coli isolates producing CTX-M ESBL and/or CMY-2 were resistant to ciprofloxacin. Furthermore, mutations were found in the gyrA and the parC genes. In most cases, the bla genes of the CTX-M ESBL and AmpC enzymes and the rmtB gene were localized to incompatibility group F (IncF) plasmids. Possible small clonal outbreaks are suggested because some E. coli isolates recovered in the same veterinary hospital were identified as identical sequence types and showed identical banding patterns in repetitive sequence-based polymerase chain reaction. The horizontal transfer of IncF plasmids and the clonal transfer of E. coli strains are suggested to play a role in the dissemination of antimicrobial resistance genes, and this transfer may occur across host species (i.e., between humans and dogs).

Acquired metallo-beta-lactamase (MBL) production is an important mechanism of carbapenem resistance. To our knowledge, carriage of two different MBLs has not been described previously in Acinetobacter spp. We present the characteristics of five Acinetobacter isolates carrying two different MBL genes. The species of all five Acinetobacter isolates with two different MBL genes were Acinetobacter genomospecies 10, and bla(IMP-1), bla(VIM-2) and bla(SIM-1) may coexist in this species. Minimum inhibitory concentrations (MICs) of imipenem for all five isolates with two different MBLs were >or=32 microg/mL, whilst those for two segregants that lost both MBLs were 0.5 microg/mL. The presence of MBL gene-carrying integrons with identical structures suggested the easily transferable nature of the elements, whilst instability of the MBL genes indicated potentially erroneous phenotypic and genetic characterisation.

Effective induction of cell-mediated immune responses strongly depends on the ability of dendritic cells (DCs) to produce Th1-polarizing cytokines, migrate to lymph nodes and stimulate T cells through antigen-presenting complex and costimulatory molecules. While various protocols for optimizing DC maturation with single or multiple stimuli mimicking infections or inflammatory milieu have been proposed for the generation of DCs with features desired for clinical application, stepwise maturation of DCs by these multiple stimuli has not been systemically assessed. Among the combinations of several immune-modulating factors with known effects on DC maturation, we found that stepwise DC maturation with cytokine cocktail (TNF-α + IL-6 + IL-1β + PGE 2 ) followed by poly(I:C) stimulation enhanced the production of IL-12 with strong allostimulatory capacity. While there were no significant differences between DC matured by simultaneous or sequential activation by cytokine cocktail and poly(I:C) in expression of markers and costimulatory molecules of mature DCs, the delivery of inflammatory signal prior to poly(I:C) results in sustained interleukin-12 expression with reduced IL-10 than DC matured by simultaneous stimulation. This sequential stimulation significantly increased migratory capacity in response to CCL21 and CXCL12 compared to DC matured with cytokine cocktail. Furthermore, these DCs retained their responsiveness to CD40L stimulation in secondary IL-12 production and efficiently generated autologous antigen-specific effector T cells as evidenced by ELISPOT assay. Thus, we propose a novel DC maturation protocol in which stimulation of DCs with cytokine cocktail and subsequently with poly(I:C) generates DCs with a high migratory capacity with a preferential Th1 inducing capacity.

The accurate and rapid identification of pathogens in blood is a major challenge in clinical pathogen diagnostics because of the high mortality of sepsis. Here we report the development of DNA microarray for the identification of pathogens causing bloodstream infections. Species-specific and bacteria- and fungi-broad-ranged probes were designed to identify 50 bacteria and 7 fungi. The specificities and sensitivities of the selected probes were successfully validated by applying reference strains. To assess the performance of the DNA microarray in a clinical setting, blind tests were performed using 112 blood culture specimens that showed preliminary presence of pathogenic microorganisms by culture-based method, resulting in the correct identification of pathogens in 104 samples showing the sensitivity of 93%. In addition, closely-related species could be discriminated by the distinct hybridization patterns. This DNA microarray-based pathogen diagnosis takes approximately 10 h starting from a positive blood culture, considerably reducing time required to sufficiently identify pathogens by subsequent agar-culture and biochemical tests which requires altogether at least 1-3 days. Also, the amount of sample required for the identification of pathogens is much less than that required for biochemical assays. Thus, the DNA microarray reported here should be useful for the effective identification of microbial pathogens in blood cultures from septicemic patients.

As part of the Tigecycline Evaluation and Surveillance Trial (TEST), Gram-negative and Gram-positive organisms were collected from 31 medical centres in nine countries in the Asia-Pacific Rim between 2004 and 2007. Overall, 34.2% of Acinetobacter spp. were multidrug-resistant, and 17.0% of Klebsiella pneumoniae and 10.6% of Escherichia coli produced extended-spectrum beta-lactamases. A total of 39.5% of Staphylococcus aureus were meticillin-resistant and 21.7% of Enterococcus faecium were vancomycin-resistant. Tigecycline MIC(90) values (minimum inhibitory concentration for 90% of the organisms) were

This study was to determine the prevalence and characteristics of CTX-M–type extended-spectrum β-lactamases (ESBLs) in nonduplicate Escherichia coli ( n = 760) and Klebsiella pneumoniae ( n = 379) bloodstream isolates collected during January 2005 to October 2007 at a university hospital (2000 beds) in Seoul, Korea. Antimicrobial susceptibilities were determined by disk diffusion and agar dilution methods. The double-disk synergy test detected ESBLs in 8.7% (66/760) of E. coli and 11.3% (43/379) of K. pneumoniae isolates. Polymerase chain reaction detected bla CTX-M in 60/66 (90.9%) E. coli and 9/43 (20.9%) K. pneumoniae isolates with the ESBL phenotype. CTX-M-14 was the most common type of CTX-M ESBLs in both E. coli ( n = 32) and K. pneumoniae ( n = 6). CTX-M-15 was the 2nd most common type of CTX-M ESBLs in E. coli ( n = 22), but it was not detected in K. pneumoniae . In addition, CTX-M-24 ( n = 2), CTX-M-65 ( n = 2), CTX-M-27 ( n = 1), and CTX-M-32 ( n = 1) were detected for the 1st time in Korea.

In this study, we examined the prevalence of and mechanisms of decreased susceptibility to either imipenem or meropenem in Klebsiella pneumoniae isolates. A total of 230 clinical isolates of K. pneumoniae were collected from 13 clinical laboratories from a nationwide distribution. The MICs of imipenem and meropenem were determined by the agar dilution method. To characterize the isolates with decreased susceptibility to carbapenems (MICs of >2 μg/mL), we performed polymerase chain reaction amplification of a variety of β-lactamase genes, isoelectric focusing, and outer membrane profile analysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry. Three isolates (BD6, BD8, and KN16) exhibited decreased susceptibility to carbapenems with imipenem MICs of 1, 4, and 8 μg/mL and meropenem MICs of 4, 8, and 4, respectively. Isolate BD6 produced bla TEM-1 , bla SHV-12 , and bla OXA-17 ; isolate BD8 produced bla GES-3 , bla SHV-12 , and bla OXA-17 ; and isolate KN16 produced bla TEM-11 , bla SHV-12 , and bla DHA-1 . In all the 3 isolates, OmpK35 porin was not expressed, and in 1 isolate (KN16), OmpK36 was not expressed either. The prevalence of decreased susceptibility to carbapenems was low (1.3%), and none of them showed overt resistance to carbapenems. Decreased susceptibility to carbapenems can occur in K. pneumoniae when bla GES-3 , bla TEM-11 , bla SHV-12 , bla OXA-17 , and/or bla DHA-1 are produced in combination with porin loss. In addition, to our knowledge, this is the 1st report of bla OXA-17 in Enterobacteriaceae.

Novel 16S rRNA methylase-mediated high-level resistance to amikacin and arbekacin has been reported recently in clinical isolates of Gram-negative bacilli only from several countries. We tested amikacin- or arbekacin-nonsusceptible Gram-negative bacilli isolated in 2003 and 2005 at a tertiary-care hospital in Korea by polymerase chain reaction to detect 16S rRNA methylase genes. armA alleles were detected in 14 isolates of Klebsiella pneumoniae , 10 other species of Enterobacteriaceae, and 16 Acinetobacter baumannii , whereas the rmtB allele was detected in 1 K. pneumoniae isolate. The resistance 1st detected in 2003 persisted in 2005. 16S rRNA methylase-producing isolates were highly resistant to arbekacin and amikacin, and were mostly coresistant to levofloxacin. Most K. pneumoniae isolates also produced extended-spectrum β-lactamases and plasmid-mediated AmpC β-lactamases, and most A. baumannii isolates were nonsusceptible to carbapenems.

Background Serratia marcescens is an aerobic gram-negative bacillus belonging to the family Enterobacteriacea. Infections caused by S marcescens may be difficult to treat because of their resistance to a variety of antibiotics, including β-lactams and aminoglycosides. Methods This study aimed to (1) identify the risk factors associated with the development of Serratia marcescens bacteriuria in neurosurgical intensive care units (NSICU); (2) genotype the pathogens to determine the source of infection; (3) compare these results with antibiograms; and (4) determine and implement appropriate control measures. A retrospective case-control study of the epidemiologic data, the surveillance of environmental cultures, and the genotyping of strains using arbitrarily primed polymerase chain reaction (AP-PCR) were performed at a 750-bed, tertiary care teaching hospital. Seventy-four bacteriuria patients were compared with 74 age/sex-matched control patients in the NSICU between March 2002 and March 2004. The factors assessed were patient demographics; duration of hospital stay; duration of indwelling catheter use before and during stay in the NSICU; chronic underlying illnesses (diabetes mellitus, cardiovascular disease, malignancy); other sites of infection; history of trauma; exposure to a nasogastric tube; mechanical ventilation; urinary catheterization; central venous catheterization; surgical drainage; tracheostomy; brain or spine surgery; and receipt of total parenteral nutrition (TPN), antimicrobials (β-lactams, aminoglycosides, quinolones, carbapenems, vancomycins), or steroids. Results Patients with S marcescens bacteriuria were more likely to have a longer NSICU stay and other sites of infection. Environmental surveillance showed the handling of urine jugs to be the point source of contamination. Genotyping and antibiograms of 14 patients were the same except for those of 2 patients. Conclusion The patient-related risk factors were identified, and a rapid identification of the organism was made. Heightened surveillance, infection control measures, and empiric therapy led to improved methods for handling urine jugs, which terminated the outbreak.

The aim of the study was to investigate the phenotypic and genetic characteristics of recently emerging cefoxitin-resistant and induction-positive isolates of Escherichia coli, Klebsiella species, and Proteus mirabilis. Strains of Enterobacteriaceae were isolated at a Korean tertiary care hospital between June and December 2002. Induction was tested using cefoxitin and aztreonam disks, the blaDHA allele was detected by PCR, and pulsed-field gel electrophoresis (PFGE) patterns were also analyzed. Among the cefoxitin-resistant isolates, 2.7% of E. coli, 21.1% of Klebsiella pneumoniae, 32.0% of Klebsiella oxytoca, and 8.3% of P. mirabilis isolates showed induction, and were blaDHA-1 allele positive. To the best of our knowledge, this is the first report of blaDHA-1 in P. mirabilis. The MICs of ceftazidime, cefotaxime, and aztreonam increased significantly by higher inoculum, suggesting that their clinical usefulness is limited. Presence of multiple PFGE patterns and identical patterns in some isolates suggest that the widely disseminated blaDHA-1 in Klebsiella species was because of both horizontal and clonal spread.

We assessed the occurrence and screening criterion for extended-spectrum beta-lactamases (ESBLs) among AmpC-producing Enterobacter cloacae, Citrobacter freundii, and Serratia marcescens. The 413 isolates (158 E. cloacae, 126 C. freundii, and 129 S. marcescens) isolated from 11 clinical laboratories in Korea were investigated. ESBL production was confirmed by double-disk synergy test and inhibitor-potentiated diffusion test using ceftazidime (CAZ), cefotaxime (CTX), aztreonam (AZT), and cefepime (FEP) with or without clavulanic acid. One hundred seven isolates (25.9%) were as ESBL producers. Of them, resistance was transferred by conjugation in 82 isolates. In transconjugants, structural genes for CTX-M (53.7%), TEM (46.3%), SHV (29.3%) were found. To evaluate the ESBL screening minimum inhibitory concentration (MIC) criteria, MICs for cefuroxime, CAZ, CTX, AZT, and FEP were determined and cutoff value was selected using receiver operator characteristic curve. The FEP MIC > or = 1 microg/mL had the highest sensitivity (95.3%), specificity (82.7%), and positive (65.8%) and negative predictive values (98.3%).

Summary We investigated an outbreak of Acinetobacter baumannii in an adult intensive care unit of Kosin University Gospel Hospital in Busan, Republic of Korea. The outbreak involved 10 cases of infection by A. baumannii producing PER-1 extended-spectrum β-lactamase over a seven-month period, and was caused by a single pulsed-field gel electrophoresis clone. The epidemic isolates were characterized by slight synergy between clavulanic acid and cefepime. Isoelectric focusing of crude bacterial extracts detected two nitrocefin-positive bands with pI values of 8.0 and 5.3. Polymerase chain reaction amplification and characterization of the amplicons by restriction analysis and direct sequencing indicated that the epidemic isolates carried a bla PER-1 determinant. The epidemic isolates were characterized by a multidrug-resistant phenotype that remained unchanged over the outbreak, including penicillins, β-lactam/β-lactamase inhibitor, extended-spectrum cephalosporins and monobactams. Isolation of infected patients and appropriate carbapenem therapy were successful in ending the outbreak. Our report indicates that the bla PER-1 resistance determinant may become an emerging therapeutic problem.

The interaction between sulbactam and imipenem was evaluated with four clinical isolates of Acinetobacter baumannii , including two isolates resistant to imipenem, one of which produced IMP-1 metallo-β-lactamase. Two isolates (one of which was imipenem-resistant) were sulbactam-resistant by undefined mechanisms. MICs were determined by standard broth microdilution methods. Time-kill assays with imipenem and sulbactam, alone or in combination at 0.5 × MIC and 1 × MIC, showed a synergic effect in all four isolates of A. baumannii after incubation for 0, 4, 8 and > 24 h at 35°C.

A sudden increase in vancomycin-resistant enterococci (VRE) infections was noted in 1998 in a tertiary care hospital in Korea. All of the VRE isolated in 1998 in the hospital were VanA type and most were multidrug-resistant Enterococcus faecium. The increase in VRE was probably due to the increased use of oral vancomycin to treat Clostridium difficile infections and clonal as well as horizontal spread. More restricted oral vancomycin use and stricter infection control measures are required to achieve a better control of the spread of VRE.

Cefoxitin-resistant Escherichia coli and Klebsiella pneumoniae are widespread in Korea. Significant proportions of them are considered to be CMY-1 producers. For effective screening of CMY-1 producers, the Hodge test was modified by using a cefoxitin disk and the performance was evaluated. The sensitivity and specifity of the test were 100% and 94.9%, respectively. The test was easier to perform than the three-dimensional extract test. This modified test should be suitable for screening CMY-1-producing strains of E. coli and K. pneumoniae.

Resistance of bacteria to antimicrobial agents is a worldwide concern. In Korea, resistant bacteria are more prevalent than in other industrialized countries. Methicillin-resistant Staphylococcus aureus, erythromycin-resistant Streptococcus pyogenes, penicillin non-susceptible pneumococci, beta-lactamase-producing gonococci, extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae, class C beta-lactamase-producing E. coli, fluoroquinolone-resistant E. coli, and aminoglycoside-resistant Acinetobacter baumannii and Pseudomonas aeruginosa are examples of resistant bacteria prevalent in Korea, and their presence suggests a high level of antimicrobial selective pressure and the nosocomial spread of resistant bacteria. Recently observed rapid increases in the incidence of vancomycin-resistant Enterococcus faecium and carbapenem-resistant P. aeruginosa present new threats in Korea.

Pseudomonas aeruginosa isolates containing the bla IMP-6 gene were recovered from 5 patients hospitalized at a tertiary-care hospital in Korea. The bla IMP-6 gene was in a class 1 integron containing 5 different insert gene cassettes. All of the isolates showed identical pattern in Spe I macrorestriction analysis.

Effects of long-term oral administration of ginseng extract on serum protein profile and immunoglobulin (Ig) isotypes were studied in mice. Ginseng extract was orally administered to healthy female mice for 52 days at doses of 30 and 150 mg/kg per day and serum protein electrophoretograms and Ig isotypes levels were evaluated. Serum level of gamma-globulin was decreased dose dependently to 82% (P0.05) and 56% (P0.01) of control values at the doses of 30 and 150 mg/kg per day, respectively. Levels of total protein, albumin, alpha2- and beta-globulin fractions, as well as the ratio of albumin to globulin (A/G) did not change significantly. However, the alpha1-globulin level increased by 24% (P0.05) at the doses of 30 and 150 mg/kg per day. Among the Ig isotypes, including IgG1, IgG2a, IgG2b, IgG3, IgM and IgA, serum IgG1 was dose dependently decreased to 68% (P0.05) of control values at the dose of 150 mg/kg per day without significant changes in other Ig isotypes. As IgG1 isotype is rarely cytotoxic and can act as a blocking antibody, it is suggested that the selective decrease in serum IgG1 induced by ginseng extract without changes in the cytotoxic antibodies such as IgG2a may be helpful for the prevention and inhibition of cancer.

This paper reviews the latest published research in healthcare management. All articles published in the last four years in the top four journals in the field are content analyzed to identify key themes that got published. The three key themes that get published in healthcare journals are: nursing retention; information technology adoption in healthcare; and quality of care. Healthcare management research allows researchers to extend and revise theories through the consideration of new contextual variables. This systematic examination will help to lay the foundation for the further expansion of the understanding of both healthcare management and of management research in general.

Summary We assumed that fibrin deposits and subsequent lysis within cerebrospinal fluid may occur in the various inflammatory disorders involving meninges. Therefore, we measured fibrin(ogen) related materials in cerebrospinal fluid of 118 patients with 21 bacterial meningitis, 22 aseptic meningitis, 75 non-meningitis associated with infectious febrile conditions and other neurologic conditions. Fibrin(ogen) related materials were quantitated as immunological components (D and E) of fibrin(ogen), which react with anti-D and anti-E using automated latex photometric immunoassay. When compared to aseptic meningitis group (mean; D=7.3, E=1.4ng/ml), the levels of D and E fibrin(ogen) related materials in cerebrospinal fluid were increased to highly significant levels in the bacterial meningitis group including tuberculous meningitis (mean; D=36.4, E=6.4ng/ml) (p

Serratia marcescens is an important nosocomial pathogen which is often resistant to multiple antimicrobial agents. An imipenem-resistant S. marcescens isolate from a urine specimen was found to carry a bla VIM-2 gene cassette on a class 1 integron. This finding indicates that bla VIM-2 is presently spreading even to Serratia spp. in Korea, which could compromise the usefulness of carbapenem in the treatment of multi-resistant Gram-negative bacilli infections. Clinical laboratory should be able to detect the VIM-2-producing isolates with even low carbapenem MIC.

Recent in-vitro test results showed that in Seoul (Korea) aerobic Gram-negative bacilli are often resistant to ampicillin and to the first-generation cephalosporins, but chloramphenicol-resistant Salmonella typhi are extremely rare. Almost all isolates of Moraxella (Branhamella) catarrhalis , 49% of Neisseria gonorrhoeae and 31% of Haemophilus influenzae were β-lactamase producers. Seventhy-two percent of pneumococci were penicillin G resistant and 62% of staphylococci were methicillin resistant. Among the Enterococcus faecium , 59% were resistant to high-level gentamicin, but glycopeptide-resistant isolates were not found. Thirty-eight percent and 5% of Bacteroides fragilis were resistant to clindamycin and cefoxitin, respectively. In conclusion, antimicrobial-resistant bacteria are prevalent in Korea.

Cycloserine cefoxitin fructose agar is a widely used selective isolation medium for Clostridium difficile from stool specimens. Yeasts often colonize in the intestine of C. difficile disease patients and, if colonized heavily, pure culture of C. difficile can be delayed. The aim of this study was to modify cycloserine cefoxitin fructose agar to suppress the growth of yeasts. Antimicrobial activities of three commonly available antifungal agents were tested against recent clinical isolates of Candida species. Amphotericin B was most active in inhibiting all isolates by ≤0.5 mg/L concentration. Cycloserine cefoxitin fructose agar was modified by adding 2 mg/L of amphotericin B. Serial ten-fold dilution of stool specimens from 126 suspected C. difficile -associated diarrhea patients were cultured both on cycloserine cefoxitin fructose agar plates and modified agar plates. Yeasts grew from 60 specimens on cycloserine cefoxitin fructose agar, but none grew on the modified medium. Growth of C. difficile was detected from 37 and 39 of 126 specimens on cycloserine cefoxitin fructose agar and modified medium, respectively. The number of C. difficile colonies was similar on both media. In conclusion, 2 mg/L of amphotericin B supplementation to cycloserine cefoxitin fructose agar can facilitate the isolation of C. difficile from stool specimens which are densely colonized with yeasts.

Division of Cardiovascular and Rare Disease, Korea Center for Disease Control and Prevention 194 Tongillo, Eunpyung-gu, Seoul, Republic of Korea Brain Korea 21 Project of Medical Science, Yonsei University, Yonsei University College of Medicine, Seoul, Republic of Korea Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea Yonsei Cell Therapy Center, Yonsei University College of Medicine, Seoul, Republic of Korea