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Abstract For the timely treatment of patients with infections in bloodstream and cerebrospinal fluid, a rapid antimicrobial susceptibility test (AST) is urgently needed. Here, we describe a direct and rapid antimicrobial susceptibility testing (dRAST) system, which can determine the antimicrobial susceptibility of bacteria from a positive blood culture bottle (PBCB) in six hours. The positive blood culture sample is directly mixed with agarose and inoculated into a micropatterned plastic microchip with lyophilized antibiotic agents. Using microscopic detection of bacterial colony formation in agarose, the total time to result from a PBCB for dRAST was only six hours for a wide range of bacterial concentrations in PBCBs. The results from the dRAST system were consistent with the results from a standard AST, broth microdilution test. In tests of clinical isolates (n = 206) composed of 16 Gram-negative species and seven Gram-positive species, the dRAST system was accurate compared to the standard broth microdilution test, with rates of 91.11% (2613/2868) categorical agreement, 6.69% (192/2868) minor error, 2.72% (50/1837) major error and 1.45% (13/896) very major error. Thus, the dRAST system can be used to rapidly identify appropriate antimicrobial agents for the treatment of blood stream infection (BSI) and antibiotic-resistant strain infections.

Group D streptococci are known to cause newborn septicemia and meningitis, but the Streptococcus bovis group strains rarely cause serious neonatal infections in Korea. Central nervous system (CNS) complications of neonatal S. bovis group infection have rarely been reported. In adults, S. bovis group strains cause bacteremia and endocarditis, and are associated with gastrointestinal malignancy. However, only a few studies have reported meningitis and septicemia in infants. Here, we describe a case of bacteremia and meningitis due to Streptococcus gallolyticus subsp. pasteurianus with a delayed CNS complication in an infant. A 28-day-old male infant was admitted to the hospital with a 1-day history of fever. Cultures of blood, cerebrospinal fluid, and urine showed the presence of S. bovis group strain-S. gallolyticus subsp. pasteurianus. He was discharged after 21 days of intravenous ampicillin and cefotaxime administration. Two weeks later, he was readmitted with a fever and short episodes of tonic-clonic movements. Brain magnetic resonance imaging showed marked bilateral frontal subdural effusion. He was discharged after 31 days of antibiotic therapy, and no neurological sequelae were observed at the 9-month follow-up. In conclusion, we present a rare case of neonatal S. gallolyticus subsp. pasteurianus infection causing urinary tract infection, septicemia, meningitis, and delayed CNS complications. This case emphasizes the need for physicians to be aware of S. bovis infection in infants.

In summer 2002, a nationwide outbreak of acute hemorrhagic conjunctivitis occurred in South Korea. The etiologic agent was confirmed as coxsackievirus A24 variant (CA24v) by virus isolation and sequencing of a part of the VP1 gene. Phylogentic analysis, based on the protease 3C sequences, showed that the Korean isolates were clustered into a lineage distinct from the CA24v isolates reported in previous outbreaks in Asia.

During the 2015 Middle East respiratory syndrome coronavirus outbreak in South Korea, we sequenced full viral genomes of strains isolated from 4 patients early and late during infection. Patients represented at least 4 generations of transmission. We found no evidence of changes in the evolutionary rate and no reason to suspect adaptive changes in viral proteins.

Eleven years ago, a 27-year-old non-drug abuser woman was admitted to the hospital due to a burn injury. During the treatment, she was diagnosed with tricuspid valve infective endocarditis caused by multi-drug resistant (MDR) Pseudomonas aeruginosa (P. aeruginosa). She underwent tricuspid valve replacement (TVR) using a bioprosthetic valve, followed by 6 weeks of meropenem antibiotic therapy. Ten years later, she was again diagnosed with prosthetic valve infective endocarditis caused by MDR P. aeruginosa. She underwent redo-TVR with a bioprosthetic valve and was treated with colistin and ciprofloxacin. Ten months later, she was again diagnosed with prosthetic valve infective endocarditis with MDR P. aeruginosa as a pathogen. She underwent a second redo-TVR with a tissue valve and was treated with colistin. Two months later, her fever recurred and she was again diagnosed with prosthetic valve infective endocarditis caused by MDR P. aeruginosa. She eventually underwent a third redo-TVR using an aortic valve homograft and was discharged from the hospital after additional 6 weeks' of antibiotic therapy. All the strains of P. aeruginosa isolated from each event of infective endocarditis were analyzed by repetitive deoxyribonucleic acid sequence-based polymerase chain reaction (rep-PCR) deoxyribonucleic acid (DNA) strain typing to determine the correlation of isolates. All of the pathogens in 11 years were similar enough to be classified as the same strain, and this is the first case report of TVR using an aortic valve homograft to treat relapsing endocarditis. [ABSTRACT FROM AUTHOR]

Background To date, more than 125 species of nontuberculous mycobacteria (NTM) have been identified. In this study, we investigated the frequency and clinical implication of the rarely isolated NTM from respiratory specimens. Methods Patients with NTM isolated from their respiratory specimens between July 1, 2010 and June 31, 2012 were screened for inclusion. Rare NTM were defined as those NTM not falling within the group of eight NTM species commonly identified at our institution: Mycobacterium avium, M. intracellulare, M. abscessus, M. massiliense, M. fortuitum, M. kansasii, M. gordonae, and M. peregrinum. Clinical, radiographic and microbiological data from patients with rare NTM were reviewed and analyzed. Results During the study period, 73 rare NTM were isolated from the respiratory specimens of 68 patients. Among these, M. conceptionense was the most common (nine patients, 12.3%). The median age of the 68 patients with rare NTM was 68 years, while 39 of the patients were male. Rare NTM were isolated only once in majority of patient (64 patients, 94.1%). Among the four patients from whom rare NTM were isolated two or more times, only two showed radiographic aggravation caused by rare NTM during the follow-up period. Conclusions Most of the rarely identified NTM species were isolated from respiratory specimens only once per patient, without concomitant clinical aggravation. Clinicians could therefore observe such patients closely without invasive work-ups or treatment, provided the patients do not have decreased host immunity towards mycobacteria. [ABSTRACT FROM AUTHOR]

Group D streptococci are known to cause newborn septicemia and meningitis, but the Streptococcus bovis group strains rarely cause serious neonatal infections in Korea. Central nervous system (CNS) complications of neonatal S. bovis group infection have rarely been reported. In adults, S. bovis group strains cause bacteremia and endocarditis, and are associated with gastrointestinal malignancy. However, only a few studies have reported meningitis and septicemia in infants. Here, we describe a case of bacteremia and meningitis due to Streptococcus gallolyticus subsp. pasteurianus with a delayed CNS complication in an infant. A 28-day-old male infant was admitted to the hospital with a 1-day history of fever. Cultures of blood, cerebrospinal fluid, and urine showed the presence of S. bovis group strain—S. gallolyticus subsp. pasteurianus. He was discharged after 21 days of intravenous ampicillin and cefotaxime administration. Two weeks later, he was readmitted with a fever and short episodes of tonic-clonic movements. Brain magnetic resonance imaging showed marked bilateral frontal subdural effusion. He was discharged after 31 days of antibiotic therapy, and no neurological sequelae were observed at the 9-month follow-up. In conclusion, we present a rare case of neonatal S. gallolyticus subsp. pasteurianus infection causing urinary tract infection, septicemia, meningitis, and delayed CNS complications. This case emphasizes the need for physicians to be aware of S. bovis infection in infants. [ABSTRACT FROM AUTHOR]

Herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2), and varicella-zoster virus (VZV) are common agents resulting in various forms of clinical manifestation from skin vesicle to disseminated viral infection. The aim of the present study was to develop a real-time PCR and melting curve analysis which detect and differentiate HSV-1, HSV-2, and VZV, to compare with PCR-RFLP using clinical specimens, and to introduce the 4-year experience in the clinical laboratory. Three pairs of primers for HSV-1, HSV- 2, and VZV were designed. Primers for human endogenous retrovirus-3 (HERV-3), an internal control, were adopted. A hundred selected specimens and many clinical specimens were tested for methods comparison and assay validation. Increased sensitivity and specificity were obtained from real-time PCR. In review of results of clinical specimens submitted to clinical laboratory, a total of 46 of 3,513 specimens were positive in cerebrospinal fluids, blood, skin vesicles, genital swabs, aqueous humor, and ear discharge. Thus, this method could be a rapid and accurate alternative to virus culture and other molecular tests for detection and typing of HSV-1, HSV-2, and VZV [ABSTRACT FROM AUTHOR]

Background: The need for mandatory confirmation of negative conversion in Klebsiella pneumoniae bacteremia (KpB) has not been adequately addressed. We conducted a retrospective case-control study of adult patients with KpB over a 5-year period in two tertiary-care hospitals to determine the risk factors for persistent bacteremia and to reevaluate the necessity of follow-up blood culture in KpB. Methods: Persistent KpB is defined as the finding of K. pneumoniae in more than two separate blood-culture samples for longer than a two-day period in a single episode. The case- and control-groups were patients with persistent and non-persistent KpB, respectively, and they were matched 1-to-3 according to age and gender. Results: Among 1068 KpB episodes analyzed after excluding polymicrobial infection and repeated KpB, follow-up blood cultures were performed in 862 cases (80.7%), 62 of which (7.2%) were persistent. Independent risk factors for persistence were intra-abdominal infection, higher Charlson's comorbidity weighted index score, prior solid organ transplantation, and unfavorable treatment response, which was defined as positivity for at least two parameters among fever, leukocytosis, and no decrease of C-reactive protein on the second day after initial culture. A proposed scoring system using four variables, namely, intra-abdominal infection, nosocomial KpB, fever and lack of C-reactive protein decrease, the last two being assessed on the second day after the initial blood culture, showed that only 4.9% of the patients with no risk factors or with only intra-abdominal infection had persistent KpB. Conclusions: Though persistent KpB is uncommon, follow-up blood culture was performed in as many as 80% of the cases in this study. A more careful clinical assessment is warranted to reduce the cost and patient inconvenience involved in follow-up blood culture. [ABSTRACT FROM AUTHOR]

Complement component 7 (C7) deficiency leads to the loss of complement lytic function, and affected patients show increased susceptibility to encapsulated organisms infection, especially Neisseria meningitidis. Recently, we have experienced a 20-year-old military trainee with meningococcal sepsis and meningitis who was diagnosed as having C7 deficiency based upon the undetectable serum C7 protein on radioimmunoassay. This case emphasizes that although C7 deficiency is rare immune disorder, it is important to be aware of possibility about late complement deficiency among patients who present with meningococcal disease. [ABSTRACT FROM AUTHOR]

Background: Local epidemiologic data on prevalent pathogens are important to guide empirical antibiotic therapy. In this study, we observed annual changes in frequency of occurrence and in vitro antimicrobial susceptibility of blood isolates over a period of 13 years. Materials and Methods: We reviewed blood isolates identified during the period from 1998 to 2010 at Seoul National University Hospital. Only first isolates for each patient were included in the analysis. We analyzed the frequency of isolates and their trend with regard to in vitro antimicrobial susceptibility. Data were presented according to guidelines of the Clinical and Laboratory Standards Institute (CLSI) (2009). Results: A total of 23,501 isolates were identified during the period from 1998 to 2010. Fifty-five percent of the isolates were gram-positive cocci, 38% were gram-negative rods, and 3% were fungi. Coagulase-negative Staphylococcus (CoNS) (24%), Escherichia co/i (16%), Staphylococcus aureus (1 0%), and Klebsiella pneumoniae (8%) were the most commonly isolated bacteria, and Candida a/b/cans (2%) was the most commonly isolated fungus. The frequency of CoNS increased from 18.0% to 26.8%, whereas the frequency of E. coil and K. pneumoniae decreased from 20.2% to 13.7% and from 11.7% to 6.7%, respectively. Overall, the proportion of methicillin-resistant S. aureus changed from 47.9% to 62.1%. In F. co/i, the resistance rate of cefotaxime and ciprofloxacin increased over a period of 13 years. However, such an increase of resistance was not observed in K. pneumoniae. In P. aeruginosa, and particularly in A. baumannii, resistance to imipenem rose alarmingly (3% in 1998 to 2 7.8% in 2010, 5% in 1998 to 68.9% in 2010, respectively). Conclusions: Over the last 13 years, the proportion of CoNS in blood isolates increased, which led to a relative decrease of isolated gram-negative rods. Proportions of MRSA showed no significant change, whereas cefotaxime resistant and ciprofloxacin resistant F. coil increased. Imipenem resistant P. aeruginosa and A. baumannii also increased during the study period. [ABSTRACT FROM AUTHOR]

Background: Healthcare-associated (HCA) infection has emerged as a new epidemiological category. The aim of this study was to evaluate the impact of HCA infection on mortality in community-onset Klebsiella pneumoniae bloodstream infection (KpBSI). Methods: We conducted a retrospective study in two tertiary-care hospitals over a 6-year period. All adult patients with KpBSI within 48 hours of admission were enrolled. We compared the clinical characteristics of HCA and community-acquired (CA) infection, and analyzed risk factors for mortality in patients with community-onset KpBSI. Results: Of 553 patients with community-onset KpBSI, 313 (57%) were classified as HCA- KpBSI and 240 (43%) as CA-KpBSI. In patients with HCA-KpBSI, the severity of the underlying diseases was higher than in patients with CA-KpBSI. Overall the most common site of infection was the pancreatobiliary tract. Liver abscess was more common in CA-KpBSI, whereas peritonitis and primary bacteremia were more common in HCA-KpBSI. Isolates not susceptible to extended-spectrum cephalosporin were more common in HCA- KpBSI than in CA-KpBSI (9% [29/313] vs. 3% [8/240]; p = 0.006). Overall 30-day mortality rate was significantly higher in HCA-KpBSI than in CA-KpBSI (22% [70/313] vs. 11% [27/240]; p = 0.001). In multivariate analysis, high Charlson's weighted index of co-morbidity, high Pitt bacteremia score, neutropenia, polymicrobial infection and inappropriate empirical antimicrobial therapy were significant risk factors for 30-day mortality. Conclusions: HCA-KpBSI in community-onset KpBSI has distinctive characteristics and has a poorer prognosis than CA-KpBSI, but HCA infection was not an independent risk factor for 30-day mortality. [ABSTRACT FROM AUTHOR]

Background: Blood culture contamination leads to inappropriate or unnecessary antibiotic use. However, practical guidelines are inconsistent about the routine use of sterile gloving in collection of blood for culture. Objective: To determine whether the routine use of sterile gloving before venipuncture reduces blood culture contamination rates. Design: Cluster randomized, assessor-blinded, crossover trial (ClinicalTrials.gov registration number: NCT00973063). Setting: Single-center trial involving medical wards and the intensive care unit. Participants: 64 interns in charge of collection of blood for culture were randomly assigned to routine-to-optional or optional-toroutine sterile gloving groups for 1854 adult patients who needed blood cultures. Intervention: During routine sterile gloving, the interns wore sterile gloves every time before venipuncture, but during optional sterile gloving, sterile gloves were worn only if needed. Measurements: Isolates from single positive blood cultures were classified as likely contaminant, possible contaminant, or truepathogen. Contamination rates were compared by using generalized mixed models. Results: A total of 10 520 blood cultures were analyzed: 5265 from the routine sterile gloving period and 5255 from the optional sterile gloving period. When possible contaminants were included, the contamination rate was 0.6% in routine sterile gloving and 1.1% in optional sterile gloving (adjusted odds ratio, 0.57 [95% CI, 0.37 to 0.87]; P = 0.009). When only likely contaminants were included, the contamination rate was 0.5% in routine sterile gloving and 0.9% in optional sterile gloving (adjusted odds ratio, 0.51 [CI, 0.31 to 0.83]; P = 0.007). Limitation: Blood cultures from the emergency department, surgical wards, and pediatric wards were not assessed. Conclusion: Routine sterile gloving before venipuncture may reduce blood culture contamination. [ABSTRACT FROM AUTHOR]

PCR fingerprinting and multilocus sequence typing were applied to determine the major molecular types of the Cryptococcus neoformans/ Cryptococcus gattii species complex in the Republic of Korea. Of the 78 strains isolated from patients diagnosed with cryptococcosis between 1990 and 2008, 96% were C. neoformans serotype A, mating type MATα and molecular type VNI. The remaining 4% were C. gattii, serotype B, mating type MATα and either molecular type VGIIb or VGIII. Of the 62 strains with known HIV status, only 14 (22.6%) were isolated from HIV-positive patients and belonged to molecular type VNI. Remarkably, 93% of the C. neoformans isolates had identical PCR fingerprint profiles with the VNIc genotype that has been identified recently as the major genotype among C. neoformans strains in China. Most strains (81.8%) of the VNIc genotype were associated with non-HIV patients compared with strains of the non-VNIc genotype (20%) ( P=0.009). Unlike the Chinese strains, a majority (60%) of the non-HIV patients infected with strains of the VNIc genotype in the Republic of Korea had serious underlying conditions, with cancer and liver disease being the most common. This study affirms VNIc to be the most prevalent genotype of C. neoformans isolated from non-HIV patients with cryptococcosis. [ABSTRACT FROM AUTHOR]

Background. Persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is associated with high mortality rates, but no treatment strategy has yet been established. We performed this study to evaluate the efficacy of linezolid with or without carbapenem in salvage treatment for persistent MRSA bacteremia. Methods. All adult patients with persistent MRSA bacteremia for ⩾7 days from January 2006 through March 2008 who were treated at Seoul National University Hospital were studied. The results of linezolid salvage therapy with or without carbapenem were compared with those of salvage therapy with vancomycin plus aminoglycosides or rifampicin. Results. Thirty-five patients with persistent MRSA bacteremia were studied. The early microbiological response (ie, negative results for follow-up blood culture within 72 hours) was significantly higher in the linezolid-based salvage therapy group than the comparison group (75% vs 17%; P=.006). Adding aminoglycosides or rifampicin to vancomycin was not successful in treating any of the patients, whereas linezolid-based therapy gave an 88% salvage success rate (P <.001). The S. aureus-related mortality rate was lower for patients treated with a linezolid salvage regimen than for patients continually treated with a vancomycin-based regimen (13% vs 53%; P=.030). Conclusions. Linezolid-based salvage therapy effectively eradicated S. aureus from the blood for patients with persistent MRSA bacteremia. The salvage success rate was higher for linezolid therapy than for vancomycin-based combination therapy. [ABSTRACT FROM AUTHOR]

Background. Candida haemulonii, a yeast species that often exhibits antifungal resistance, rarely causes human infection. During 2004-2006, unusual yeast isolates with phenotypic similarity to C. haemulonii were recovered from 23 patients (8 patients with fungemia and 15 patients with chronic otitis media) in 5 hospitals in Korea. Methods. Isolates were characterized using D1/D2 domain and ITS gene sequencing, and the susceptibility of the isolates to 6 antifungal agents was tested in vitro. Results. Gene sequencing of the blood isolates confirmed C. haemulonii group I (in 1 patient) and Candida pseudohaemulonii (in 7 patients), whereas all isolates recovered from the ear were a novel species of which C. haemulonii is its closest relative. The minimum inhibitory concentration (MIC) ranges of amphotericin B, fluconazole, itraconazole, and voriconazole for all isolates were 0.5-32 μg/mL (MIC50, 1 μg/mL), 2-128 μg/mL (MIC50, 4 μg/mL), 0.125-4 μg/mL (MIC50, 0.25 μg/mL), and 0.03-2 μg/mL (MIC50, 0.06 μg/mL), respectively. All isolates were susceptible to caspofungin (MIC, 0.125-0.25 μg/mL) and micafungin (MIC, 0.03-0.06 μg/mL). All cases of fungemia occurred in patients with severe underlying diseases who had central venous catheters. Three patients developed breakthrough fungemia while receiving antifungal therapy, and amphotericin B therapeutic failure, which was associated with a high MIC of amphotericin B (32 μg/mL), was observed in 2 patients. Conclusions. Candida species that are closely related to C. haemulonii are emerging sources of infection in Korea. These species show variable patterns of susceptibility to amphotericin B and azole antifungal agents. [ABSTRACT FROM AUTHOR]

Objectives: To assess the prevalence and genotypes of Ambler class A extended-spectrum β-lactamases (ESBLs) in Korea.Methods: Clinical isolates of Escherichia coli and Klebsiella pneumoniae collected from 12 Korean hospitals during February–July 2003 were evaluated. Antimicrobial susceptibilities were determined by disc diffusion and agar dilution methods, and the putative ESBL-producing strains were tested by the double-disc synergy method. Detection of genes encoding class A β-lactamases was performed by PCR amplification, and the PCR products were subjected to direct sequencing.Results: The double-disc synergy test showed positive results in 9.3% (23/246) of E. coli and 23.0% (55/239) of K. pneumoniae isolates. The most prevalent types of Ambler class A ESBLs in E. coli isolates were CTX-M-15 (n = 4) and CTX-M-3 (n = 3), and those in K. pneumoniae isolates were SHV-12 (n = 30) and CTX-M-3 (n = 13). Two isolates produced both SHV-12 and GES-3, simultaneously.Conclusions: CTX-M-type and/or SHV-12 ESBL-producing E. coli and K. pneumoniae isolates are spreading, and a GES-type ESBL has emerged in Korea. [ABSTRACT FROM AUTHOR]

A vancomycin-resistant Enterococcus (VRE) outbreak occurred at a hematology/oncology (HO) service in a tertiary acute care hospital, 1 January to 30 April 2002. This study was undertaken to identify risk factors, and to establish relations between seasonal factors and this VRE outbreak. Every patient ( n= 82) and health care worker (HCW) ( n= 31) at the HO unit was screened by rectal swab and stool culture during the VRE outbreak. Environmental surface culture ( n= 35) and pulsed-field gel electrophoresis (PFGE) of VRE isolates were preformed. Among a total of 82 patients, 17 had VRE. All VRE isolates were E. faecium, the 6 studied further were Van A with identical PFGE patterns. Cultures of surfaces and HCWs were negative for VRE. Prolonged hospital stay ( p= 0.02), male gender ( p= 0.02), and care in a 6-bed room ( p< 0.01) were risk factors for acquisition of VRE. An association with the VRE outbreak period was found again for long hospital stay, but also for the antibiotic usage pattern, frequent surgery and a high proportion of new inexperienced staff (52% vs 4% before the outbreak ( p< 0.01, Fisher's exact test). Sudden personnel turnover in high-risk units should be avoided. [ABSTRACT FROM AUTHOR]

Objective: In the past decade, a new problem in Klebsiella pneumoniae strains has emerged: plasmid-mediated AmpC enzymes. This study was conducted to investigate the activity of cefepime against clinical isolates by determining the activities of cefepime and three other parenteral -lactam agents in standard and high inoculum MIC tests.Methods: A total of 61 K. pneumoniae blood isolates, including 28 isolates producing AmpC-type -lactamases (14 isolates of DHA-1 and 14 isolates of CMY-1-like) and 33 isolates producing extended-spectrum -lactamases (ESBLs) (32 isolates of TEM- or SHV-related and one isolate of CTX-M-14-like), were included in the study. Antimicrobial susceptibilities were determined using broth microdilution MIC tests with standard and 100-fold-higher inocula. The inoculum effect was defined as an eight-fold or greater MIC increase on testing with the higher inoculum.Results: In tests with AmpC -lactamase-producing K. pneumoniae isolates and their transconjugants, the inoculum effect was most consistently detected with cefepime, cefotaxime and ceftazidime, as inoculum effects were consistently detected in ESBL-producing isolates. However, the inoculum effect was least frequently detected with imipenem.Conclusion: Although the inoculum effect is an in vitro laboratory phenomenon, these results suggest that cefepime may be a less than reliable agent for therapy in cases of high inoculum infections caused by AmpC -lactamase-producing K. pneumoniae. [ABSTRACT FROM AUTHOR]

Background. Enterobacter species have become increasingly important nosocomial pathogens. However, resistance to cephalosporins often complicates the treatment of Enterobacter infection. This study was conducted to evaluate the predictors of mortality and the impact of cephalosporin resistance on outcome in patients with Enterobacter bacteremia. Methods. A total of 183 patients with Enterobacter bacteremia were retrospectively analyzed. Broad-spectrum cephalosporin resistance was defined as in vitro resistance to cefotaxime or ceftazidime. The main outcome measure was the 30-day mortality rate. Results. Of 183 patients, 86 (47%) had bacteremia caused by broad-spectrum cephalosporin-resistant Enterobacter species, and their infections were classified as resistant. The 30-day mortality rate of patients with resistant infections (the resistant group) was significantly higher than that of patients with susceptible infections (the susceptible group) (3 3.7% vs. 18.6%; P = .021). When the 30-day mortality rates were compared according to the primary sites of infection and underlying conditions, the 30-day mortality rates of the resistant group were significantly higher than those of the susceptible group, in patients with an unknown primary site of infection, or in patients with septic shock. Multivariate analysis showed that broad-spectrum cephalosporin resistance was one of the independent risk factors associated with 30-day mortality (odds ratio [OR], 3.69; 95% confidence interval [CI], 1.01-13.52; P = .049). Presentation with septic shock and an increasing Acute Physiology and Chronic Health Evaluation II score were also independent risk factors for mortality (OR, 59.91 [95% CI, 14.93-240.15; P< .001] and 1.52 [95% CI, 1.24-1.86; P<.001], respectively). Conclusions. Broad-spectrum cephalosporin resistance adversely affects the outcome of patients with Enterobacter bacteremia, especially those with an unknown primary site of infection and those with septic shock. [ABSTRACT FROM AUTHOR]

Objective: To determine the impact of delayed treatment of methicillin-resistant Staphylococcus aureus bacteraemia (MRSA bacteraemia) on mortality.Patients and methods: We used two different and complementary approaches: a retrospective cohort study and a matched case–control study. Of the total of all patients with S. aureus bacteraemia in a tertiary hospital over a 4 year period, 127 patients with MRSA bacteraemia were enrolled in the cohort study. The cases for the case–control study were defined as patients who received appropriate empirical treatment for MRSA bacteraemia; the controls, who were patients who received inappropriate empirical treatment for MRSA bacteraemia, were selected according to the matching variables of age, sex, severity of underlying illness, classification of main underlying disease and prior hospital stay. On the 14-point matching scale that was used to select the best controls, the average score (±S.D.) of the 30 controls was 11.2 (±2.0).Results: In the cohort study, the difference in S. aureus bacteraemia-related mortality between appropriate (30%, 9/30) and inappropriate (39%, 38/97) empirical treatment was not significant (P=0.36). In addition, multivariate analysis did not indicate that inappropriate empirical treatment was associated with mortality when independent predictors for mortality were considered (adjusted OR 1.1, 95% CI 0.4–3.1). In the case–control study, S. aureus bacteraemia-related mortality in case patients was 30% (9/30) and in control patients 33% (10/30) (P>0.99, McNemar's test). In four of the nine discordant pairs, the case patients died whereas the control patients lived.Conclusions: Our data suggest that an initial delay of 2 days in the use of appropriate antibiotics, especially of vancomycin or other glycopeptides, before the preliminary microbiological report may not adversely affect the outcome in patients with MRSA bacteraemia. [ABSTRACT FROM AUTHOR]

Evaluates the risk factors for mortality and influence of delayed receipt of antimicrobial therapy on clinical outcome of Pseudomonas aeruginosa bacteremia. Inclusion of severe sepsis and pneumonia as risk factors for mortality; Association between delay in starting effective antimicrobial therapy for P. aeruginosa bacteremia and higher mortality.

Determines the outcome of Staphylococcus aureus bacteremia (SAB) on mortality. Impact of methicillin resistance and an initial delay of appropriate antibiotics; Role of noneradicable or noneradicated foci, underlying cirrhosis and cancer as independent predictors of mortality; Absence of differences in the associated mortality rate between methicillin-resistant SAB and methicillin-susceptible SAB; Independent association of underlying cirrhosis and methicillin-resistant SAB with mortality.

Investigates the viral etiology of acute hemorrhagic conjunctivitis caused by coxsackievirus A24 in South Korea in 2002. Outbreak of acute hemorrhagic conjunctivitis in the country; Background of the study population; Nucleotide sequences of the protease 3c region.

The work reported here is the first nationwide, multicenter surveillance study conducted in Korea to obtain data on fluconazole susceptibility of Candida albicans ( C. albicans) isolates. A total of 1137 isolates of C. albicans obtained from 17 university hospitals in South Korea during the 6-month period, July through December 2004, were tested. No resistant strains were observed in any of the isolates. Only five of the 1137 isolates (0.44%) of C. albicans were found to be susceptible dose dependent, with all remaining strains (99.56%) susceptible to fluconazole. Trailing growth at 48 h was found in only four isolates (0.35%). [ABSTRACT FROM AUTHOR]

Objectives Methicillin-resistant Staphylococcus aureus (MRSA), originally restricted to hospitals, has emerged as a significant pathogen in the community. Although MRSA accounts for over 60% of S. aureus in tertiary hospitals in Korea, little is known about the epidemiology of community-associated MRSA (CA-MRSA). Methods From January to July 2005, a hospital laboratory-based survey was conducted in seven community-based or tertiary hospitals. The medical records and Health Insurance Review Agency databases were reviewed and MRSA isolated from patients without apparent risk factors was defined as CA-MRSA. Susceptibilities to 12 antibiotics were tested by the disc diffusion method. SCCmec typing, Panton–Valentine leucocidin (PVL) gene detection and multilocus sequence typing (MLST) were performed according to published protocols. Results Of 3251 S. aureus, 1900 (58.4%) were MRSA. CA-MRSA accounted for 112 (5.9%) of the MRSA. Of the 112 CA-MRSA isolates, 27 and 33 were found to be pathogens and colonizers, respectively. Fifty-two isolates from the patients with chronic otitis media were classified as ‘undetermined’. Most of the 27 CA-MRSA patients had skin and soft tissue infections or acute ear infections. None of the patients died during the study period. Among 72 isolates tested, 64% were multidrug-resistant. SCCmec type IVa was the most common type among the colonizers and pathogens. On MLST analysis, ST72 was predominant, but ST5 and ST239 were prevalent in the ‘undetermined’ group. None possessed the PVL gene. Conclusions Despite MRSA-endemic hospital settings, CA-MRSA infections are not common in Korea. A new clone of CA-MRSA, ST72-SCCmec type IVa without the PVL gene, is the most common form. [ABSTRACT FROM AUTHOR]

Objectives This ambidirectional intervention study was performed to examine the impact of a change in antibiotic policy on extended-spectrum β-lactamase (ESBL) prevalence in a childrens hospital with a high prevalence of ESBL production among Escherichia coli and Klebsiella pneumoniae. Methods The use of extended-spectrum cephalosporins was restricted and use of β-lactam/ β-lactamase inhibitor combinations was encouraged from 2002. All strains of E. coli and K. pneumoniae isolated from sterile body fluids from 1999 to 2005 were analysed for β-lactamase production and the prevalences of ESBL production were compared at three periods; pre-intervention (1999–2001), transitional period (2002–03) and post-intervention (2004–05). Results Comparing the pre- and post-intervention periods, overall piperacillin/tazobactam use increased from 2.2 to 108.0 days on antibiotics/1000 patient admission days/year (AD) (P for trend P for trend E. coli (n = 128) and K. pneumoniae (n = 124), the overall prevalence of ESBL producers decreased from 39.8% (41/103) to 22.8% (18/79) (P for trend = 0.018). This decreasing trend of ESBL production was more evident for K. pneumoniae (64.1% to 25.6%; P for trend E. coli (25.0% to 19.4%; P for trend = 0.514). The mortality rates of invasive disease caused by E. coli or K. pneumoniae remained unchanged. Conclusions The substitution of piperacillin/tazobactam for extended-spectrum cephalosporins successfully decreased the prevalence of ESBL production of K. pneumoniae and E. coli in an institute for children where ESBLs were endemic. The impact of change in antibiotic policy was more evident in K. pneumoniae than E. coli. [ABSTRACT FROM AUTHOR]

Cord blood units (CBUs) for transplantation should be free of communicable disease and must contain a specific amount of total nucleated cells and CD34 + cells. Although posttransplantation cytomegalovirus (CMV) infections are from latent infection in patients, ensuring CMV-free CBUs by performing CMV-specific IgM and nucleic acid amplification testing (NAT) is one of the mandatory procedures for the safety of CBUs. However, the exclusion policies (based on these test results) vary among nations and institutions. We tested 28,000 processed CBUs between May 2006 and June 2014. The cord blood leukocytes from CMV IgM-positive samples were then subjected to NAT. The total nucleated cell and CD34 + cell counts were measured for each CBU, and the results were compared to the CMV IgM and IgG results. The seroprevalence of CMV among pregnant women was 98.1% (18,459/18,818) for IgG and 1.7% (441/25,293) for IgM. The concentration and the total number of CD34 + cells were significantly higher in CBUs from IgM-negative mothers compared to those from IgM-positive mothers (72.4/μl vs. 57.2/μl, respectively, p < 0.0001; 1.45 × 10 6 /unit vs. 1.15 × 10 6 /unit, respectively, p < 0.0001). Among CBUs with positive CMV IgM in their mothers' plasma or cord blood plasma, only 0.58% of the samples (3/517) had a positive NAT. The number of excluded CBUs from inventory due to positive CMV IgM in the cord blood was 54 of 18,326 (0.3%). For inventory purposes, it is appropriate to remove CBUs with positive cord blood CMV IgM findings irrespective of the NAT status as well as positive maternal CMV IgM in South Korea.