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Abstract This study evaluated the determinants of mortality and the T cell immune response in patients with persistent Staphylococcus aureus bacteremia (SAB). This was a prospective cohort study and patients with confirmed SAB were enrolled from 2008 to 2020. We compared clinical, microbiological, and genotypic features between surviving and deceased patients with persistent SAB. The concentrations of cytokines and the proportions of IFN-γ secreting CD4+ T cells were measured serially during the bacteremia period. Of the 1760 patients, 242 had persistent bacteremia (PB), and 49 PB patients died within 30 days. In the multivariate analysis, the APACHE II score and female sex were independently associated with 30 days mortality. The level of IL-10 was significantly increased in the plasma of patients with a high Pitt bacteremia score and those who died within 12 weeks from the index day. The proportion of IFN-γ-secreting CD4+ T cells were the highest just before the positive-to-negative conversion of blood cultures in patients with a low Pitt bacteremia score and those who survived for 12 weeks. The level of IL-10 is correlated with clinical outcomes in PB patients. IFN-γ secreting CD4+ T cells might play a pivotal role in SAB PB.

The characteristics of severe human parainfluenza virus (HPIV)–associated pneumonia in adults have not been well evaluated. We investigated epidemiologic and clinical characteristics of 143 patients with severe HPIV-associated pneumonia during 2010–2019. HPIV was the most common cause (25.2%) of severe virus-associated hospital-acquired pneumonia and the third most common cause (15.7%) of severe virus-associated community-acquired pneumonia. Hematologic malignancy (35.0%), diabetes mellitus (23.8%), and structural lung disease (21.0%) were common underlying conditions. Co-infections occurred in 54.5% of patients admitted to an intensive care unit. The 90-day mortality rate for HPIV-associated pneumonia was comparable to that for severe influenza virus–associated pneumonia (55.2% vs. 48.4%; p = 0.22). Ribavirin treatment was not associated with lower mortality rates. Fungal co-infections were associated with 82.4% of deaths. Clinicians should consider the possibility of pathogenic co-infections in patients with HPIV-associated pneumonia. Contact precautions and environmental cleaning are crucial to prevent HPIV transmission in hospital settings.

ABSTRACT The incidence of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) infection is increasing and is associated with vancomycin treatment failures. However, studies investigating the risk factors for treatment failure in hVISA infection are limited. Patients with hVISA bacteremia treated with vancomycin over 7 days between August 2008 and June 2020 were enrolled in this study. Clinical and microbiological characteristics were compared between vancomycin treatment failure and success groups to identify the risk factors for vancomycin treatment failure. Among the 180 patients with hVISA bacteremia, 102 patients treated with vancomycin over 7 days were included. Vancomycin treatment failed in 80 (78%) patients. Patients in the vancomycin treatment failure group were older (P < 0.001) and more frequently had solid cancer (P = 0.04) than those in the vancomycin treatment success group. Solid organ transplantation (SOT) was more frequent (P < 0.001) in the vancomycin treatment success group. The Charlson comorbidity index (P = 0.01) and Acute Physiology and Chronic Health Evaluation II scores (P < 0.001) were higher in the vancomycin treatment failure group. In multivariate analysis, independent risk factors for vancomycin treatment failure were old age and severity of bacteremia. SOT and vancomycin minimal inhibitory concentration (MIC) ≤ 1.0 mg/L using the broth microdilution (BMD) method were associated with successful vancomycin treatment. Old age and infection severity were independent risk factors for vancomycin treatment failure. Vancomycin MIC using the BMD method is an important risk factor for vancomycin treatment failure, and its use should be considered in hVISA bacteremia.IMPORTANCEIn this study, we assessed the clinical and microbiological characteristics of heterogeneous vancomycin-intermediated Staphylococcus aureus (hVISA) bacteremia and identified risk factors for vancomycin treatment failure. We found that advanced age and severity of infection were independent risk factors for vancomycin treatment failure. On the other hand, solid organ transplantation and a low vancomycin minimal inhibitory concentration were associated with successful vancomycin treatment. This study highlights the importance of vancomycin minimal inhibitory concentration in hVISA bacteremia.

We investigated the proportion and characteristics of severe Corynebacterium striatum pneumonia in South Korea during 2014–2019. As part of an ongoing observational study of severe pneumonia among adult patients, we identified 27 severe C. striatum pneumonia cases. Most (70.4%) cases were hospital-acquired, and 51.9% of patients were immunocompromised. C. striatum cases among patients with severe hospital-acquired pneumonia (HAP) increased from 1.0% (2/200) during 2014–2015 to 5.4% (10/185) during 2018–2019, but methicillin-resistant Staphylococcus aureus (MRSA) infections among severe HAP cases decreased from 12.0% to 2.7% during the same timeframe. During 2018–2019, C. striatum was responsible for 13.3% of severe HAP cases from which bacterial pathogens were identified. The 90-day mortality rates were similarly high in the C. striatum and MRSA groups. C. striatum was a major cause of severe HAP and had high mortality rates. This pathogen is emerging as a possible cause for severe pneumonia, especially among immunocompromised patients.

ABSTRACT This study aimed to identify which streptococcal species are closely associated with infective endocarditis (IE) and to evaluate risk factors for mortality in patients with streptococcal IE. We performed a retrospective cohort study of all patients with streptococcal bloodstream infection (BSI) from January 2010 to June 2020 in a tertiary hospital in South Korea. We compared clinical and microbiological characteristics of streptococcal BSIs according to the diagnosis of IE. We performed multivariate analysis to evaluate the risk of IE according to streptococcal species and risk factors for mortality in streptococcal IE. A total of 2,737 patients were identified during the study period, and 174 (6.4%) were diagnosed with IE. The highest IE prevalence was in patients with Streptococcus mutans BSI (33% [9/27]) followed by S. sanguinis (31% [20/64]), S. gordonii (23% [5/22]), S. gallolyticus (16% [12/77]), and S. oralis (12% [14/115]). In multivariate analysis, previous IE, high-grade BSI, native valve disease, prosthetic valve, congenital heart disease, and community-onset BSI were independent risk factors for IE. After adjusting for these factors, S. sanguinis (adjusted OR [aOR], 7.75), S. mutans (aOR, 5.50), and S. gallolyticus (aOR, 2.57) were significantly associated with higher risk of IE, whereas S. pneumoniae (aOR, 0.23) and S. constellatus (aOR, 0.37) were associated with lower risk of IE. Age, hospital-acquired BSI, ischemic heart disease, and chronic kidney disease were independent risk factors for mortality in streptococcal IE. Our study points to significant differences in the prevalence of IE in streptococcal BSI according to species. IMPORTANCE Our study of risk of infective endocarditis in patients with streptococcal bloodstream infection demonstrated that Streptococcus sanguinis, S. mutans, and S. gallolyticus were significantly associated with higher risk of infective endocarditis. However, when we evaluated the performance of echocardiography in patients with streptococcal bloodstream infection, patients with S. mutans and S. gordonii bloodstream infection had a tendency of low performance in echocardiography. There are significant differences in the prevalence of infective endocarditis in streptococcal bloodstream infection according to species. Therefore, performing echocardiography in streptococcal bloodstream infection with a high prevalence of, and significant association with, infective endocarditis is desirable.

Background: A stockpile of antiviral drugs is important for mitigating a novel influenza pandemic. Recently, intervention strategies against such a pandemic have improved significantly, affecting the required size and composition of the stockpile. Our goal is to estimate the optimal ratio of conventional to newer antiviral drugs. Method: We estimated epidemic parameters from daily-case data about H1N1pdm09 in the Republic of Korea, and used a deterministic ordinary differential equation model and stochastic simulation to predict the number of patients in a future pandemic. We considered an antiviral stockpile containing neuraminidase inhibitors (NAI) and a new drug, cap-dependent endonuclease inhibitor (CENI), seeking the optimum ratio of the two drugs under different epidemiological and economic assumptions. Results: With an effective reproductive number of 1.36, the expected cumulative cases did not exceed 30 % of the population in all vaccination scenarios. If the non-pharmaceutical intervention strategy is intensified and the effective reproductive number is decreased to 1.29, a 20 % antiviral stockpile of the population is sufficient. Assuming that CENI is prescribed for 10 % of patients, the expected total number of cases is decreased from 30 % to approximately 25 % of the population. If the cost of CENI is triple that of NAI, no expenditures beyond the current budget are necessary; if it is quintuple, expenditures increase by 17 %. Conclusion: Stockpiling CENI reduces the number of patients by reducing the infectious period. However, the government needs to consider the cost-effective stockpile ratio of such new drugs. This will depend not only on the cost of the drugs, but on factors difficult to anticipate, such as the transmissibility of the virus, the time needed for vaccine development, and (especially) the emergence of resistance. If this information can be estimated, our model can be used to obtain the optimum.

Abstract Concern about resistance to chlorhexidine has increased due to the wide use of the latter. The impact of the qacA/B and smr chlorhexidine tolerance genes on the outcome of methicillin-resistant Staphylococcus aureus (MRSA) infections is unclear. We evaluated the prevalence and clinical impact of, and microbiological risk factors for, qacA/B tolerance in MRSA bacteremia. MRSA bacteremia that occurred more than two days after intensive care unit admission between January 2009 and December 2018 was identified from a prospective cohort of S. aureus bacteremia in a tertiary-care hospital from South Korea. A total of 183 MRSA blood isolates was identified, and the major genotype found was ST5-MRSA-II (87.4%). The prevalences of qacA/B and smr were 67.2% and 3.8%, respectively. qacA/B-positive isolates were predominantly ST5-MRSA-II (96.7% [119/123]), the dominant hospital clone. In a homogenous ST5-MRSA-II background, qacA/B positivity was independently associated with septic shock (aOR, 4.85), gentamicin resistance (aOR, 74.43), and non-t002 spa type (aOR, 74.12). qacA/B positivity was found to have decreased significantly in ST5-MRSA-II in association with a decline in qacA/B-positive t2460, despite the increasing use of chlorhexidine since 2010 (P

Rifampin resistance (RIF-R) in Staphylococcus aureus (S. aureus) with rpoB mutations as one of its resistance mechanisms has raised concern about clinical treatment and infection prevention strategies. Data on the prevalence and molecular epidemiology of RIF-R S. aureus blood isolates in South Korea are scarce. We used broth microdilution to investigate RIF-R prevalence and analyzed the rpoB gene mutation in 1615 S. aureus blood isolates (772 methicillin-susceptible and 843 methicillin-resistant S. aureus (MRSA)) from patients with bacteremia, between 2008 and 2017. RIF-R prevalence and antimicrobial susceptibility were determined. Multilocus sequence typing was used to characterize the isolate’s molecular epidemiology; Staphylococcus protein A (spa), staphylococcal cassette chromosome mec (SCCmec), and rpoB gene mutations were detected by PCR. Among 52 RIF-R MRSA isolates out of 57 RIF-R S. aureus blood isolates (57/1615, 0.4%; 5 methicillin-susceptible and 52 MRSA), ST5 (44/52, 84.6%), SCCmec IIb (40/52, 76.9%), and spa t2460 (27/52, 51.9%) were predominant. rpoB gene mutations with amino acid substitutions showed that A477D (17/48, 35.4%) frequently conferred high-level RIF resistance (MIC > 128 mg/L), followed by H481Y (4/48, 8.3%). RIF-R S. aureus blood isolates in South Korea have unique molecular characteristics and are closely associated with rpoB gene mutations. RIF-R surveillance through S. aureus–blood isolate epidemiology could enable effective therapeutic management.

BackgroundIsolation of COVID-19 patients is a crucial infection control measure to prevent further SARS-CoV-2 transmission, but determining an appropriate timing to end the COVID-19 isolation is a challenging. We evaluated the performance of the self-test rapid antigen test (RAT) as a potential proxy to terminate the isolation of COVID-19 patients.Materials and methodsSymptomatic COVID-19 patients were enrolled who were admitted to a regional community treatment center (CTC) in Seoul (South Korea). Self-test RAT and the collection of saliva samples were performed by the patients, on a daily basis, until patient discharge. Cell culture and subgenomic RNA detection were performed on saliva samples.ResultsA total of 138 pairs of saliva samples and corresponding RAT results were collected from 34 COVID-19 patients. Positivity of RAT and cell culture was 27% (37/138) and 12% (16/138), respectively. Of the 16 culture-positive saliva samples, seven (43.8%) corresponding RAT results were positive. Using cell culture as the reference standard, the overall percent agreement, percent positive agreement, and percent negative agreement of RAT were 71% (95% CI, 63–78), 26% (95% CI, 12–42), and 82% (95% CI, 76–87), respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of the RAT for predicting culture results were 44% (95% CI, 20–70), 75% (95% CI, 66–82), 18% (95% CI, 8–34), and 91% (95% CI, 84–96), respectively.ConclusionAbout half of the patients who were SARS-CoV-2 positive based upon cell culture results gave negative RAT results. However, the remaining positive culture cases were detected by RAT, and RAT showed relatively high negative predictive value for viable viral shedding.

Abstract Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) has emerged as an important cause of infection. We conducted a longitudinal study to evaluate changes in clinical and microbiological characteristics as well as outcomes of sequence type (ST) 72 MRSA bacteremia. We reviewed adult patients enrolled in a prospective cohort with ST72 MRSA bacteremia from August 2008 to December 2018 at Asan Medical Center, Seoul, South Korea. Changes in clinical characteristics, outcomes, and microbiological characteristics of patients over time were evaluated. Generalized linear and linear regression models were used to evaluate changes. Of the 1,760 isolates, 915 (62%) were MRSA bacteremia and 292 (31.9%) were ST72 MRSA. During the study period, the relative risk (RR) of MRSA bacteremia decreased annually by 3.7%; however, among MRSA bacteremia, RR of ST72 MRSA increased annually by 8.5%. Vancomycin minimum inhibitory concentration (MIC) decreased over the study period. Metastatic infection, persistent bacteremia, and recurrence of bacteremia within 12 weeks decreased significantly. There were no significant changes in 30-d and 12-week mortality. Antibiotic susceptibility of ST72 MRSA was evaluated, and the resistance rate to erythromycin decreased significantly. ST72 MRSA incidence increased annually; its vancomycin MIC and erythromycin resistance rate decreased over the 11 years.

AbstractBackground Q fever endocarditis is a major cause of culture-negative endocarditis. The role of Coxellia burnetii is underestimated because it is difficult to diagnose. We investigated the significance of C. burnetii as the cause of culture-negative endocarditis and vascular infection by examining blood and tissue specimens using serological testing and polymerase chain reaction (PCR).Methods All patients with infective endocarditis or large vessel vasculitis were prospectively enrolled at a tertiary-care hospital from May 2016 through September 2020. Q fever endocarditis and vascular infection were diagnosed based on: (1) positive PCR for a cardiac valve or vascular tissue, (2) positive PCR for blood or phase I immunoglobulin G (IgG) ≥ 6400, or (3) phase I IgG ≥ 800 and < 6400 with morphologic abnormality. PCR targeted C. burnetii transposase gene insertion element IS1111a.Results Of the 163 patients, 40 (25%) had culture-negative endocarditis (n = 35) or vascular infection (n = 5). Of the 40 patients, 24 (60%) were enrolled. Eight (33%) were diagnosed with Q fever endocarditis or vascular infection. Of these 8 patients, 6 had suspected acute Q fever endocarditis or vascular infection with negative phase I IgG. Six patients were not treated for C. burnetii, 4 were stable after surgery. One patient died due to surgical site infection after 5 months post-operatively and one died due to worsening underlying disease.Conclusions Approximately one-third of patients with culture-negative endocarditis and vascular infection was diagnosed as Q fever. Q fever endocarditis and vascular infection may be underestimated in routine clinical practice in South Korea.KEY MESSAGEQ fever endocarditis and vascular infection may be underestimated in routine clinical practice, thus, try to find evidence of C. burnetti infection in suspected patients by all available diagnostic tests including PCR.

Background/Aims We evaluated the usefulness in kidney transplant (KT) candidates of cytomegalovirus (CMV)-specific enzyme-linked immunospot (ELISPOT) assays for predicting the development of post-transplant CMV infections. Methods All adult recipients admitted for living-donor KT between March 2014 and March 2015 were prospectively enrolled except donor CMV-seropositive and recipient seronegative (D+/R–) recipients. All the enrolled patients underwent CMV-specific ELISPOT assays before transplant, and a researcher blinded to the results of these assays examined the patients for CMV infection at least 6 months post-transplant. Results Of 133 KT recipients, 44 (33%) developed CMV infections. When we used the cut-off determined by receiver operator characteristic curve, 16 of the 34 patients (47%) with negative pp65-specific ELISPOT results (< 11 spots/200,000 cells) developed CMV infections, whereas 28 of the 99 patients (39%) with positive pp65-specific ELISPOT results at baseline (≥ 11 spots/200,000 cells) developed CMV infections after KT (p = 0.02). Based on the multivariable Cox regression model, negative pp65-specific ELISPOT assay results was an independent risk factor for CMV infection (adjusted hazard ratio [AHR], 1.87; 95% confidence interval [CI], 1.01 to 3.46; p = 0.047) as well as age (AHR, 1.05; 95% CI, 1.01 to 1.08; p = 0.007). Conclusions Pre-transplant CMV-specific ELISPOT assay appears to predict the development of CMV infections after KT in recipients at moderate risk such as CMV-seropositive recipients (Clinical Trial Registration Number NCT 02025335).

A linear–shaped small organic molecule (E)-4-(5-(3,5-dimethoxy-styryl)thiophen-2-yl)-7-(5″-hexyl-[2,2′:5′,2″-terthiophen]-5-yl)benzo[c][1,2,5]thiadiazole (MBTR) comprising a benzothiadiazole (BTD) acceptor linked with the terminal donors bithiophene and dimethoxy vinylbenzene through a π-bridge thiophene was synthesized and analyzed. The MBTR efficiently tuned the thermal, absorption, and emission characteristics to enhance the molecular packing and aggregation behaviors in the solid state. The obtained optical bandgap of 1.86 eV and low-lying highest occupied molecular orbital (HOMO) level of −5.42 eV efficiently lowered the energy losses in the fabricated devices, thereby achieving enhanced photovoltaic performances. The optimized MBTR:PC71BM (1:2.5 w/w%) fullerene-based devices showed a maximum power conversion efficiency (PCE) of 7.05%, with an open-circuit voltage (VOC) of 0.943 V, short-circuit current density (JSC) of 12.63 mA/cm2, and fill factor (FF) of 59.2%. With the addition of 3% 1,8-diiodooctane (DIO), the PCE improved to 8.76% with a high VOC of 1.02 V, JSC of 13.78 mA/cm2, and FF of 62.3%, which are associated with improved charge transport at the donor/acceptor interfaces owing to the fibrous active layer morphology and favorable phase separation. These results demonstrate that the introduction of suitable donor/acceptor groups in molecular design and device engineering is an effective approach to enhancing the photovoltaic performances of organic solar cells.

We report a case series of severe human bocavirus–associated pneumonia in adults in Seoul, South Korea. The virus accounted for 0.5% of all severe pneumonia cases. Structural lung disease and hematologic malignancy were common underlying diseases. Overall death rate was 54.5%. Higher death rates were associated with co-infection (83.3%) and immunocompromise (80.0%).

Background/Aims Methicillin-resistant Staphylococcus aureus bacteremia (MRSAB) is a major bloodstream infection with a high mortality rate. Identification of factors associated with early mortality in MRSAB patients would be useful for predicting prognosis and developing new therapeutic options. Methods A prospective cohort of MRSAB patients was examined between August 2008 and June 2011. Early and late mortality was defined as death within 2 and 28 days of blood culture, respectively. The clinical and microbiological characteristics in the early and late mortality and survival groups were compared. Risk factors associated with severe sepsis or septic shock were also investigated. Results A total of 385 adult MRSAB patients whose S. aureus isolates were available were enrolled; of these patients, 25 patients (6.5%) and 50 (13%) died early and late, respectively. Compared with both the late-mortality group and the survival group, severe sepsis or septic shock was a statistically significant independent risk factor associated with early mortality. Rapidly or ultimately fatal McCabe and Jackson classification (adjusted odds ratio [aOR], 1.94; 95% confidence interval [CI], 1.25 to 3.02) and pneumonia (aOR, 2.04; 95% CI, 1.03 to 4.02) were independently associated with severe sepsis or septic shock. A vancomycin minimum inhibitory concentration (MIC) ≥ 1.5 μg/mL was associated with a reduced incidence of severe sepsis or septic shock (aOR, 0.53; 95% CI, 0.34 to 0.84). Conclusions Severity of illness seems to be the most important risk factor associated with early mortality in MRSAB. Although vancomycin MIC was not independently associated with early mortality, reduced vancomycin susceptibility appears to be linked to reduced disease severity.

Background: The sensitivity of galactomannan (GM) assay is suboptimal for detecting invasive pulmonary aspergillosis (IPA) in serum samples. However, the clinical characteristics, radiologic findings, and outcomes in patients with GM-negative IPA have not been fully elucidated. Methods: Over a 7-year period, adult patients with proven or probable IPA by the EORTC/MSG definition were retrospectively enrolled. Patients with negative GM results and positive Aspergillus spp. cultures from sputum or bronchoalveolar lavage were classified into GM-negative IPA group. GM-positive and culture-negative IPA cases were selected at a 1:2 ratio. Results: Thirty-four patients with GM-negative IPA were compared to 68 randomly selected patients from 158 patients with GM-positive and culture-negative IPA. Patients with diabetes mellitus, chronic kidney disease, and steroid use were more common but those with hematologic malignancy, prior receipt of mold-active antifungal drugs, and neutropenia were less common in GM-negative IPA than in GM-positive IPA. Regarding radiologic findings, angioinvasive aspergillosis was less common in GM-negative IPA than in GM-positive IPA. The median number of days from diagnosis to appropriate antifungal therapy was higher in GM-negative IPA than in GM-positive IPA. Multivariate analysis indicated that neutropenia (adjusted odds ratio [aOR], 0.10) and prior receipt of mold-active antifungal drugs (aOR, 0.12) were inversely associated with GM-negative IPA. The 30-day and 90-day mortality were similar between the two groups. Conclusion: Neutropenia and prior receipt of mold-active antifungal drugs before GM assay were independently associated with GM positivity among patients with proven/probable IPA. Angioinvasive aspergillosis was less common in GM-negative IPA than in GM-positive IPA. Keywords: Galactomannan, Invasive pulmonary aspergillosis, Neutropenia

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease caused by SFTS virus (SFTSV) infection. Despite a gradual increase of SFTS cases and high mortality in endemic regions, no specific viral therapy nor vaccine is available. Here, we developed a single recombinant plasmid DNA encoding SFTSV genes, Gn and Gc together with NP-NS fusion antigen, as a vaccine candidate. The viral antigens were fused with Fms-like tyrosine kinase-3 ligand (Flt3L) and IL-12 gene was incorporated into the plasmid to enhance cell-mediated immunity. Vaccination with the DNA provides complete protection of IFNAR KO mice upon lethal SFTSV challenge, whereas immunization with a plasmid without IL-12 gene resulted in partial protection. Since we failed to detect antibodies against surface glycoproteins, Gn and Gc, in the immunized mice, antigen-specific cellular immunity, as confirmed by enhanced antigen-specific T cell responses, might play major role in protection. Finally, we evaluated the degree of protective immunity provided by protein immunization of the individual glycoprotein, Gn or Gc. Although both protein antigens induced a significant level of neutralizing activity against SFTSV, Gn vaccination resulted in relatively higher neutralizing activity and better protection than Gc vaccination. However, both antigens failed to provide complete protection. Given that DNA vaccines have failed to induce sufficient immunogenicity in human trials when compared to protein vaccines, optimal combinations of DNA and protein elements, proper selection of target antigens, and incorporation of efficient adjuvant, need to be further investigated for SFTSV vaccine development.

β-lactam–avibactam combinations have been proposed as carbapenem-sparing therapies, but little data exist on their in vitro activities in infections with high bacterial inocula. We investigated the in vitro efficacies and the inoculum effects of ceftazidime–avibactam and aztreonam–avibactam against extended-spectrum β-lactam-resistant Enterobacterales blood isolates. A total of 228 non-repetitive extended-spectrum β-lactam-resistant Escherichia coli and Klebsiella pneumoniae blood isolates were prospectively collected in a tertiary center. In vitro susceptibilities to ceftazidime, aztreonam, meropenem, ceftazidime–avibactam, and aztreonam–avibactam were evaluated by broth microdilution method using standard and high inocula. An inoculum effect was defined as an eightfold or greater increase in MIC when tested with the high inoculum. Of the 228 isolates, 99% were susceptible to ceftazidime–avibactam and 99% had low aztreonam–avibactam MICs (≤8 mg/L). Ceftazidime–avibactam and aztreonam–avibactam exhibited good in vitro activities; MIC50/MIC90 values were 0.5/2 mg/L, 0.125/0.5 mg/L, and ≤0.03/0.25 mg/L, respectively, and aztreonam–avibactam was more active than ceftazidime–avibactam. The frequencies of the inoculum effect with ceftazidime–avibactam and aztreonam–avibactam were lower than with meropenem (14% vs. 38%, p < 0.001 and 30% vs. 38%, p = 0.03, respectively). The β-lactam-avibactam combinations could be useful as carbapenem-sparing strategies, and aztreonam–avibactam has the better in vitro activity but is more subject to the inoculum effect than ceftazidime–avibactam.

ObjectivesThe addition of bevacizumab to standard chemotherapy has been improved survival outcomes in patients with metastatic colorectal cancer. However, the combination of bevacizumab with oxaliplatin-based chemotherapy as first-line treatment showed limited survival benefit. The purpose of this study was to investigate the clinical efficacy and toxicity of the combination of bevacizumab to oxaliplatin and leucovorin (FOLFOX4) in the first-line treatment of patient with metastatic colorectal cancer. MethodsBetween December 2004 and September 2009, medical records of patients who were diagnosed with metastatic colorectal cancer and received the first line chemotherapy with bevacizumab and FOLFOX4, were retrospectively reviewed. ResultsA total of forty patients were analyzed. The median age of the patients was 55 years (range, 33-80), and 55% was male. The patients received a total of 206 cycles of therapy (median 4 cycles per patient; range 1 – 15 cycles). Of these 40 patients, none achieved complete response (CR) and 15 achieved a partial response (PR), for the overall response rate (ORR) 37.5% (95% CI, 22.5-52.5). Median progression free survival (PFS) was 6.9 months (95% CI, 3.4-10.5) and median overall survival (OS) was 22.6 months (95% CI, 17.3-27.8The most common grade 3 or 4 hematologic toxicity and non-hematologic toxicity were neutropenia (10.0%) and diarrhea (10.0%), respectively. Two patients experienced gastrointestinal perforation. ConclusionsIn this study, the combination bevacizumab with FOLFOX4 was associated with favorable OS, but did not showed favorable PFS and ORR.

We conducted a prospective cohort study at a community facility designated for the isolation of individuals with asymptomatic or mild COVID-19 between 10 January and 22 February 2021 to investigate the relationship of viral shedding with symptom changes of COVID-19. In total, 89 COVID-19 adult patients (12 asymptomatic, 16 presymptomatic, 61 symptomatic) were enrolled. Symptom scores, the genomic RNA and subgenomic RNA of SARS-CoV-2 from saliva samples with a cell culture were measured. Asymptomatic COVID-19 patients had a similar viral load to symptomatic patients during the early course of the disease, but exhibited a rapid decrease in viral load with the loss of infectivity. Subgenomic RNA and viable virus by cell culture in asymptomatic patients were detected only until 3 days after diagnosis, and the positivity of the subgenomic RNA and cell culture in symptomatic patients gradually decreased in both from 40% in the early disease course to 13% at 10 days and 4% at 8 days after the symptom onset, respectively. In conclusion, symptomatic patients have a high infectivity with high symptom scores during the early disease course and gradually lose infectivity depending on the symptom. Conversely, asymptomatic patients exhibit a rapid decrease in viral load with the loss of infectivity, despite a similar viral load during the early disease course.

Abstract Objectives The both values of neutrophil lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR) were reported as indexes of systemic inflammation and readily available and inexpensive prognostic markers in patients with solid cancer. The objective of this study was to clarify whether the NLR and PLR were significant prognostic markers in Korean diffuse large B-cell lymphoma (DLBCL) patients treated with R-CHOP as a first line therapy. Methods : We retrospectively collected the clinical data of ninety nine DLBCL patients treated with R-CHOP from 2004 to 2012 and analyzed. NLR and PLR were calculated from complete blood count (CBC) and differential leukocyte count. Results : In univariate analysis, NLR was significantly associated with 5-year progression free survival(PFS) rate (P= 0.039), but not significantly associated with 5-year overal survival (OS) rate (P= 0.276). PLR was not significantly associated with 5-year PFS (P= 0.632) and OS rate (P= 0.855). In multivariate analysis, NLR was not a significant independent prognostic factor for 5-year PFS (P= 0.415) and OS rate (P= 0.991). Conclusion : The NLR can be considered a useful predictor of survival outcome. The PLR is not a valid predictor of survival outcome.

Severe fever with thrombocytopenia syndrome (SFTS) was reported in China in 2009 and in South Korea in 2012. We found retrospective evidence of SFTS virus infection in South Korea in 2010, suggesting that infections in South Korea occurred before previously reported and were more concurrent with those in China.

BACKGROUND:Empiric antibiotic therapy for suspected hematogenous vertebral osteomyelitis (HVO) should be initiated immediately in seriously ill patients and may be required in those with negative microbiological results. The aim of this study was to inform the appropriate selection of empiric antibiotic regimens for the treatment of suspected HVO by analyzing antimicrobial susceptibility of isolated bacteria from microbiologically proven HVO. METHOD:We conducted a retrospective chart review of adult patients with microbiologically proven HVO in five tertiary-care hospitals over a 7-year period. The appropriateness of empiric antibiotic regimens was assessed based on the antibiotic susceptibility profiles of isolated bacteria. RESULTS:In total, 358 cases of microbiologically proven HVO were identified. The main causative pathogens identified were methicillin-susceptible Staphylococcus aureus (33.5%), followed by methicillin-resistant S. aureus (MRSA) (24.9%), Enterobacteriaceae (19.3%), and Streptococcus species (11.7%). Extended spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and anaerobes accounted for only 1.7% and 1.4%, respectively, of the causative pathogens. Overall, 73.5% of isolated pathogens were susceptible to levofloxacin plus rifampicin, 71.2% to levofloxacin plus clindamycin, and 64.5% to amoxicillin-clavulanate plus ciprofloxacin. The susceptibility to these oral combinations was lower in cases of healthcare-associated HVO (52.6%, 49.6%, and 37.6%, respectively) than in cases of community-acquired HVO (85.8%, 84.0%, and 80.4%, respectively). Vancomycin combined with ciprofloxacin, ceftriaxone, ceftazidime, or cefepime was similarly appropriate (susceptibility rates of 93.0%, 94.1%, 95.8%, and 95.8%, respectively). CONCLUSIONS:Based on our susceptibility data, vancomycin combined with a broad-spectrum cephalosporin or fluoroquinolone may be appropriate for empiric treatment of HVO. Fluoroquinolone-based oral combinations may be not appropriate due to frequent resistance to these agents, especially in cases of healthcare-associated HVO.

BACKGROUND:Ocular involvement of candidemia can result in serious complications, including vision loss. This study investigated the risk factors for ocular involvement in patients with candidemia and the outcomes of treatment. METHODS:Episodes of candidemia in hospitalized adults who underwent ophthalmic examinations within 2 weeks of candidemia onset between January 2014 and May 2017 were retrospectively reviewed. Their demographic characteristics, antifungal treatments, and visual outcomes were evaluated. RESULTS:During the study period, 438 adults were diagnosed with candidemia, with 275 (62.8%) undergoing ophthalmic examinations within 2 weeks. Of these 275 patients, 59 (21.5%) had fundoscopic abnormalities suggestive of ocular involvement, including 51 with chorioretinitis and eight with Candida endophthalmitis. Eleven patients were symptomatic. Persistent candidemia (adjusted odd ratio [aOR], 2.55; 95% confidence interval [CI], 1.29-5.08; P = 0.01), neutropenia during the preceding 2 weeks (aOR, 2.92; 95% CI, 1.14-7.53; P = 0.03), and C. albicans infection (aOR, 2.15; 95% CI, 1.09-4.24; P = 0.03) were independently associated with ocular involvement. Among the 24 patients with neutropenia, 41.7% had ocular involvements at the initial examination. Ophthalmologic examination even before the neutrophil recovery was positive in one-third of neutropenic patients. Out of the 37 patients in whom ocular outcomes after 6 weeks were available, 35 patients showed favorable or stable fundoscopic findings. Two patients had decreased visual acuity despite the stable fundoscopic finding. CONCLUSION:Neutropenia within two weeks of candidemia was a risk factor for ocular involvement. More than 80 percent of patients with ocular involvements were asymptomatic, emphasizing the importance of routine ophthalmic examinations. The median 6 weeks of systemic antifungal treatment resulted in favorable outcomes in 89.2% of patients.

Ceftazidime-avibactam (CAZ-AVI) and aztreonam-avibactam (AZT-AVI) are novel antibiotic combinations active against multidrug-resistant Gram-negative pathogens. This study aimed to evaluate their in vitro activities and inoculum effects in carbapenem-resistant Enterobacterales (CRE), including carbapenemase-producing (CP)-CRE and non-CP-CRE. A total of 81 independent clinical isolates of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae were collected. CAZ-AVI and AZT-AVI minimal inhibitory concentrations (MICs) were evaluated by broth microdilution using standard and high inocula. The inoculum effect was defined as an ≥8-fold increase in MIC with high inoculum. Phenotypic determination of β-lactam resistance mechanism and PCR for carbapenemase genes were performed. Of the 81 CRE isolates, 35 (43%) were CP-CRE. Overall, 73% of the isolates were susceptible to CAZ-AVI, and 95% had low AZT-AVI MICs (≤8 µg/mL). The MIC50/MIC90s of CAZ-AVI and AZT-AVI were 4/≥512 µg/mL and 0.5/4 µg/mL, respectively. CAZ-AVI was more active against non-CP-CRE than against CP-CRE (susceptibility 80% vs. 63%, p = 0.08; MIC50/MIC90, 2/16 μg/mL vs. 4/≥512 μg/mL), whereas AZT-AVI was more active against CP-CRE (MIC50/MIC90, 0.25/1 μg/mL vs. 0.5/8 μg/mL). All four isolates with high AZT-AVI MIC (≥16 μg/mL) were resistant to CAZ-AVI, but only 18% (4/22) of CAZ-AVI-resistant isolates had high AZT-AVI MIC. The rates of the inoculum effect for CAZ-AVI and AZT-AVI were 18% and 47%, respectively (p < 0.001). Interestingly, the frequency of the AZT-AVI inoculum effect was higher in K. pneumoniae than E. coli (64% vs. 8%, p < 0.001). AZT-AVI is more active against CRE than CAZ-AVI, even in CP-CRE and CAZ-AVI-resistant isolates. The presence of a substantial inoculum effect may contribute to clinical failure in high-inoculum infections treated with AZT-AVI.

Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV). We investigated the detailed kinetics of serologic response in patients with SFTS. Twenty-eight patients aged ≥18 years were enrolled between July 2015 and October 2018. SFTS was confirmed by detecting SFTSV RNA in their plasma using reverse transcription polymerase chain reaction. SFTSV-specific IgG and IgM were measured using immunofluorescence assay (IFA) and enzyme-linked immunosorbent assay (ELISA). We found that SFTSV-specific IgG was detected at days 5–9 after symptom onset, and its titer was rising during the course of disease. SFTSV-specific IgM titer peaked at around week 2–3 from symptom onset. The SFTSV-specific seropositive rates for days 5–9, 10–14, 15–19, and 20–24 from symptom onset using IFA and ELISA were 63%, 76%, 90%, and 100%, and 58%, 86%, 100%, and 100%, respectively, for IgG, whereas they were 32%, 62%, 80%, and 100%, and 53%, 62%, 70%, and 100%, respectively, for IgM. The delayed IgM response could be attributed to the low sensitivity of SFTSV-specific IgM IFA or ELISA and/or impaired immune responses. The IgM test using IFA or ELISA that we used in this study is, therefore, insufficient for the early diagnosis of SFTS.

One dimensional (1D) metal sulfide nanostructures are one of the most promising materials for photocatalytic water splitting reactions to produce hydrogen (H2). However, tuning the nanostructural, optical, electrical and chemical properties of metal sulfides is a challenging task for the fabrication of highly efficient photocatalysts. Herein, 1D CdS nanorods (NRs) were synthesized by a facile and low-cost solvothermal method, in which reaction time played a significant role for increasing the length of CdS NRs from 100 nm to several micrometers. It is confirmed that as the length of CdS NR increases, the visible photocatalytic H2 evolution activity also increases and the CdS NR sample obtained at 18 hr. reaction time exhibited the highest H2 evolution activity of 206.07 μmol.g−1.h−1. The higher H2 evolution activity is explained by the improved optical absorption properties, enhanced electronic bandstructure and decreased electron-hole recombination rate.

OBJECTIVES:Statins, which are lipid-lowering agents, have anti-inflammatory and immunomodulatory properties that may affect the occurrence of various infectious diseases. We assessed whether statins increase the risk of herpes zoster (HZ) with propensity score-matching. METHODS:The study was based on the National Health Insurance database and its subset database of the "medical check-up" population of South Korea. These cohorts consist of about one million and 570,000 people, respectively, representative of the entire population of South Korea. We identified 103,930 statin users and 430,685 non-statin users. After propensity score-matching, 25,726 statin users and the same number of non-statin users were finally analyzed. The development of HZ was monitored in these matched pairs over the 11 years from 2003 to 2013. RESULTS:Statin users had a significantly higher risk of HZ than non-statin users: hazard ratio (HR) 1.25 (95% CI, 1.15 to 1.37) (p < .0001). The risk of HZ associated with statins was especially high in the elderly: HR 1.39 (95% CI, 1.12 to 1.73) in the over 70-year-olds (p = 0.003) and HR 1.18 (95% CI, 1.00 to 1.39) in the 60-to-69-year-olds (p = 0.056). Furthermore, there was a significant p for trend in terms of cumulative dose effect between the risk of HZ and the duration of statin use (p < .0001). CONCLUSIONS:These epidemiologic findings provide strong evidence for an association between HZ and statin use, and suggest that unnecessary statins should be avoided.

Although the incidence of Mycobacterium avium complex (MAC) lung disease is increasing, the long-term natural course of the nodular bronchiectatic form of MAC lung disease is not well described. The objective of our study is to evaluate long-term radiologic changes in untreated MAC lung disease by analyzing serial chest computed tomography (CT) scan findings.Of 104 patients with MAC lung disease, we selected 40 untreated nodular bronchiectatic MAC patients who underwent serial chest CTs without treatment for at least four years (mean = 6.23 years). Majority of patients have minimal symptoms. Two chest radiologists retrospectively reviewed initial and final chest CT scans. Each chest CT scan was scored for presence and extent of bronchiectasis, cellular bronchiolitis, consolidation, cavity, and nodule (maximum score: 30).Of 40 patients, 39 (97.5%) experienced a significant increase in overall CT score (overall difference = 4.89, p

Serologic diagnosis is one of the most widely used diagnostic methods for Q fever, but the window period in antibody response of 2 to 3 weeks after symptom onset results in significant diagnostic delay. We investigated the diagnostic utility of Q fever PCR from formalin-fixed liver tissues in Q fever patients with acute hepatitis.We reviewed the clinical and laboratory data in patients with Q fever hepatitis who underwent liver biopsy during a 17-year period, and whose biopsied tissues were available. We also selected patients who revealed granuloma in liver biopsy and with no Q fever diagnosis within the last 3 years as control. Acute Q fever hepatitis was diagnosed if two or more of the following clinical, serologic, or histopathologic criteria were met: (1) an infectious hepatitis-like clinical feature such as fever (≥ 38°C) with elevated hepatic transaminase levels; (2) exhibition of a phase II immunoglobulin G (IgG) antibodies titer by IFA of ≥ 1:128 in single determination, or a four-fold or greater rise between two separate samples obtained two or more weeks apart; (3) histologic finding of biopsy tissue showing characteristic fibrin ring granuloma.A total of 11 patients with acute Q fever hepatitis were selected and analyzed. Of the 11 patients, 3 (27%) had exposure to zoonotic risk factors and 7 (63%) met the serologic criteria. Granulomas with either circumferential or radiating fibrin deposition were observed in 10 cases on liver biopsy and in 1 case on bone marrow biopsy. 8 (73%) revealed positive Coxiella burnetii PCR from their formalin-fixed liver tissues. In contrast, none of 10 patients with alternative diagnosis who had hepatic granuloma revealed positive C. burnetii PCR from their formalin-fixed liver tissues.Q fever PCR from formalin-fixed liver tissues appears to be a useful adjunct for diagnosing Q fever hepatitis.

BACKGROUND:Diagnosis of pneumocystis pneumonia (PCP) relies on microscopic visualization of P. jirovecii, or detection of Pneumocystis DNA in respiratory specimens, which involves invasive procedures such as bronchoalveolar lavage. The (1-3)-β-D-glucan (BG) assay has been proposed as a less invasive and less expensive diagnostic test to rule out PCP. We therefore compared blood levels of BG in patients with PCP with those of patients with candidemia, chronic disseminated candidiasis (CDC), invasive aspergillosis, mucormycosis, and tuberculosis and those of healthy volunteers. METHODS:Adult patients who were diagnosed with PCP, candidemia, CDC, invasive aspergillosis, mucormycosis, and tuberculosis whose blood samples were available, and healthy volunteers were enrolled in a tertiary hospital in Seoul, South Korea, during a 21-month period. The blood samples were assayed with the Goldstream Fungus (1-3)-β-D-glucan test (Gold Mountain River Tech Development, Beijing, China). RESULTS:A total of 136 individuals including 50 patients P. jirovecii,15 candidemia, 6 CDC, 15 invasive aspergillosis, 10 mucormycosis, and 40 controls (20 TB and 20 healthy volunteers) were included. The mean±SD of the concentration of 1-3-β-D-glucan in the patients with PCP (290.08 pg/mL±199.98) were similar to those of patients with candidemia (314.14 pg/mL±205.60, p = 0.90 at an α = 0.005) and CDC (129.74 pg/mL±182.79, p = 0.03 at an α = 0.005), but higher than those of patients with invasive aspergillosis (131.62 pg/mL±161.67, p = 0.002 at an α = 0.005), mucormycosis (95.08 pg/mL±146.80, p 31.25 pg/mL, which is highly sensitive for PCP versus tuberculosis plus healthy volunteers at the expense of specificity, the BG assay had a sensitivity of 92% (95% CI 81%-98%) and a specificity of 55% (95% CI 39%-71%). CONCLUSIONS:The BG assay appears to be a useful adjunct test for PCP.

The influence of lithium doping concentration on the crystallization, the surface morphology, and the luminescent properties of Y1.92O3:Eu0.08 ceramic phosphors were investigated. The crystallinity, the surface morphology, and the photoluminescence (PL) of ceramics depended highly on the Li-doping concentrations. The relationship between the crystalline and morphological structures and the luminescent properties was studied, and Li-doping was found to affect not only the enhanced crystallinity but also the luminescent brightness of Y1.92O3:Eu0.08 ceramics. In particular, the incorporation of Li+ ion into the Y2O3 lattice could induce remarkable increase in the PL intensity. The strongest emission intensity was observed with Y1.68Li0.24O3-δ:Eu0.08 ceramics whose brightness was increased by a factor of 6.5 in comparison with that of Y1.92O3:Eu0.08 ceramics.

Complicated intra-abdominal infection (cIAI) is infection that extends beyond the hollow viscus of origin into the peritoneal space, and is associated with either abscess formation or peritonitis. There are few studies that have assessed the actual costs and outcomes associated with failure of initial antibiotic therapy for cIAI. The aims of this study were to evaluate risk factors and impact on costs and outcomes of failure of initial antibiotic therapy for community-onset cIAI.A retrospective study was performed at eleven tertiary-care hospitals. Hospitalized adults with community-onset cIAI who underwent an appropriate source control procedure between August 2008 and September 2011 were included. Failure of initial antibiotic therapy was defined as a change of antibiotics due to a lack of improvement of the clinical symptoms and signs associated with cIAI in the first week.A total of 514 patients hospitalized for community-onset cIAI were included in the analysis. The mean age of the patients was 53.3 ± 17.6 years, 72 patients (14%) had health care-associated infection, and 48 (9%) experienced failure of initial antibiotic therapy. Failure of initial antibiotic therapy was associated with increased costs and morbidity. After adjustment for covariates, patients with unsuccessful initial therapy received an additional 2.9 days of parenteral antibiotic therapy, were hospitalized for an additional 5.3 days, and incurred $3,287 in additional inpatient charges. Independent risk factors for failure of initial antibiotic therapy were health care-associated infection, solid cancer, and APACHE II ≥13.To improve outcomes and costs in patients with community-onset cIAI, rapid assessment of health care-associated risk factors and severity of disease, selection of an appropriate antibiotic regimen accordingly, and early infection source control should be performed.

BACKGROUND: Viral pathogens have not generally been regarded as important causes of severe hospital-acquired pneumonia (HAP), except in patients with hematologic malignancy or transplant recipients. We investigated the role and distribution of viruses in adult with severe HAP who required intensive care. METHODS: From March 2010 to February 2012, adult patients with severe HAP required admission to the intensive care unit (ICU), 28-bed medical ICU in a tertiary care hospital, were prospectively enrolled. Respiratory viruses were detected using multiplex reverse-transcription polymerase chain reaction and/or shell vial culture. RESULTS: A total of 262 patients were enrolled and 107 patients (40.8%) underwent bronchoscopic BAL for etiologic diagnosis. One hundred and fifty-six patients (59.5%) had bacterial infections and 59 patients (22.5%) had viral infections. Viruses were detected in BAL fluid specimens of 37 patients (62.7%, 37/59). The most commonly identified viruses were respiratory syncytial virus and parainfluenza virus (both 27.1%, 16/59), followed by rhinovirus (25.4%, 15/59), and influenza virus (16.9%, 10/59). Twenty-one patients (8.0%, 21/262) had bacterial-viral coinfections and Staphylococcus aureus was the most commonly coexisting bacteria (n = 10). Viral infection in non-immunocompromised patients was not uncommon (11.1%, 16/143), although it was not as frequent as that in immunocompromised patients (36.4%, 43/119). Non-immunocompromised patients were significantly older than immunocompromised patients and had significantly higher rates of underlying chronic obstructive pulmonary disease, tuberculous destroyed lung and chronic kidney disease. The 28 day mortalities of patients with bacterial infections, viral infections and bacterial-viral coinfections were not significantly different (29.5%, 35.6% and 19.0%, respectively; p = 0.321). CONCLUSIONS: Viral pathogens are not uncommon in adult patients with severe HAP who required ICU admission. Since viral pathogens may cause severe HAP and could be a potential source of viral transmission, further investigation is required to delineate the role of viral pathogens in severe HAP.

The usefulness of bronchoalveolar lavage (BAL) fluid cellular analysis in pneumonia has not been adequately evaluated. This study investigated the ability of cellular analysis of BAL fluid to differentially diagnose bacterial pneumonia from viral pneumonia in adult patients who are admitted to intensive care unit.BAL fluid cellular analysis was evaluated in 47 adult patients who underwent bronchoscopic BAL following less than 24 hours of antimicrobial agent exposure. The abilities of BAL fluid total white blood cell (WBC) counts and differential cell counts to differentiate between bacterial and viral pneumonia were evaluated using receiver operating characteristic (ROC) curve analysis.Bacterial pneumonia (n=24) and viral pneumonia (n=23) were frequently associated with neutrophilic pleocytosis in BAL fluid. BAL fluid median total WBC count (2,815/µL vs. 300/µL, P

OBJECTIVES: Mannose-binding lectin (MBL) is an important component of innate immunity. Structural and promoter polymorphisms in the MBL2 gene that are responsible for low MBL levels are associated with susceptibility to infectious diseases. The objective of this study was to investigate the association of serum MBL levels and MBL2 polymorphisms with persistent Staphylococcus aureus bacteremia (SAB) in adult Korean patients. METHODS: We conducted a case-control study nested in a prospective cohort of patients with SAB. The study compared 41 patients with persistent bacteremia (≥7 days) and 46 patients with resolving bacteremia (

OBJECTIVES: Catheter-related Staphylococcus aureus bacteremia (CRSAB) occasionally persists despite catheter removal and initiation of appropriate antimicrobial therapy. The aim of this study was to determine the incidence, risk factors, and outcomes of persistent CRSAB after catheter removal and initiation of antimicrobial therapy. METHODS: Consecutive patients with CRSAB were prospectively included from over a 41-month period. We compared the clinical features, 40 bacterial virulence genes, and outcomes between patients with persistent CRSAB (i.e., bacteremia for >3 days after catheter removal and initiation of appropriate antimicrobial therapy) and non-persistent CRSAB. RESULTS: Among the 220 episodes of CRSAB, the catheter was kept in place in 17 (6%) and removed in 203 (94%) cases. In 43 (21%) of the 203 episodes, bacteremia persisted for >3 days after catheter removal and initiation of antimicrobial therapy. Methicillin resistance (Odds ratio [OR], 9.01; 95% confidence interval [CI], 3.05-26.61; P

Background: Sporadic measles outbreaks have continued to occur in Korea, mainly in adults in their 20s and 30s, most notably in 2014 and 2019. We here evaluated the possible causes of a low seroprevalance of measles by testing young healthcare workers (HCWs). Materials and Methods: This study was conducted in a 2,743-bed tertiary-care hospital in Seoul between 2020 and 2021. We performed a measles antibody test (chemiluminescence immunoassay), measured the IgM/IgG index ratio, and conducted an avidity test at 1-month after Measles-Mumps-Rubella (MMR) vaccination in HCWs who had been seronegative for measles. Measles vaccination histories were obtained from the national vaccine registry. Results: Of the 3,173 HCWs newly employed in our hospital during the study period, 54 with a negative measles IgG at commencement were enrolled. Thirty six (67%) of these subjects were female, and the median age was 25 years (interquartile range [IQR]: 24 - 27). Fourty nine (91%) showed seroconversion at 1 month after the first vaccination. Of these individuals, 38 received both measles IgM and IgG test, and all had an IgM/IgG index <1. Of the 49 seroconverters, all HCWs showed a high avidity index. According to the national immunization registry, 45 (83%) received at least 2 doses of an MMR vaccination. Conclusion: Secondary vaccine failure may underlie vaccine failure in young Korean adults. HCWs born after 1985 with a negative measles antibody may need only a single dose booster vaccination rather than a 2-dose vaccination regimen. [ABSTRACT FROM AUTHOR]

The present study examined the adaptive personality, communication patterns and the adaptation experience of Korean expatriates in Indonesia. Based on Y. Y. Kim's (1988, 2001, 2005, 2012, 2015, 2018) Integrative Communication Theory of Cross-Cultural Adaptation, four hypotheses were developed linking three key factors: adaptive personality, host communication competence, host interpersonal communication and psychological health. Numeric data were collected in a questionnaire survey among 76 Korean expatriates living in Indonesia. As predicted, the positive correlations between the research variables suggest that expatriates with higher level of self-efficacy, host communication competence and more active engagements in interpersonal communication with host nationals experience greater psychological health vis-à-vis the host environment. The present study affirms Y. Y. Kim's theorems that emphasize the centrality of communication in the process of expatriate workers' cross-cultural adaptation. The present analysis highlights the practical insights on how to recruit, select and train international employees to facilitate their successful adaptation overseas. [ABSTRACT FROM AUTHOR]

The sensitivity of the (1-3)-β-D-glucan (BDG) diagnostic test for candidemia varies in different clinical settings, and its usefulness in early diagnosis of candidemia is suboptimal. We evaluated the sensitivity of the test for early candidemia prediction. All adult patients with culture-proven candidemia who underwent a serum Goldstream Fungus (1-3)-β-D-Glucan Test within seven days prior to candidemia onset at a tertiary referral hospital between January 2017 and May 2021 were included. Any-positive BDG results within seven days prior to candidemia onset were obtained in 38 out of 93 (40.9%) patients. The positive rate increased when the test was performed near the day of candidemia onset (P=0.04) but reached only 52% on the day of candidemia onset. We observed no significant differences between BDG-positive and -negative groups in terms of underlying disease, risk factors for candidemia, clinical presentation, origin of candidemia, and 30-day mortality. Candida albicans was significantly associated with positive BDG results than with all-negative BDG results (P=0.04). The Goldstream BDG test is unreliable for candidemia prediction because of its low sensitivity. Negative BDG results in patients with a high risk of invasive candidiasis should be interpreted with caution. [ABSTRACT FROM AUTHOR]

배경: We aimed to identify which streptococcal species are closely associated with infective endocarditis (IE) and whether streptococcal species affect mortality in streptococcal IE. 방법: We performed a retrospective cohort study of all patients with streptococcal bloodstream infections (BSI) from 2010 to 2020 in a tertiary hospital in South Korea. We collected echocardiographic results within one month from BSI and compared clinical characteristics of patients with streptococcal BSI according to the diagnosis of IE. We performed multivariable analysis to evaluate risk of IE according to the species in streptococcal BSI and to identify risk factors for mortality in streptococcal IE. 결과: A total of 2737 patients were identified during the study period; 1177 (43%) patients performed echocardiography within one month from BSI, and 174 (6%) were diagnosed with IE. The highest IE prevalence was found with Streptococcus mutans (33% [9/27]) followed by S. sanguinis (31% [20/64]), S. gordonii (23% [5/22]), S. gallolyticus (16% [12/77]), and S. oralis (12% [14/115]) (Figure). In multivariable analysis, previous IE, high-grade BSI, native valve disease, prosthetic valve disease, congenital heart disease, and community-onset BSI were independent risk factors for IE. After adjusting for these risk factors, S. pneumoniae (adjusted OR [aOR] 0.23; 95% confidence interval [CI] 0.08-0.54), S. constellatus (aOR 0.37; 95% CI 0.12-0.88), S. sanguinis (aOR 7.75; 95% CI 3.64-16.00), S. gallolyticus (aOR 2.57; 95% CI 1.12-5.43), and S. mutans (aOR 5.50; 95% CI 1.83-15.70) were significantly associated with IE. Age, community-onset BSI, ischemic heart disease, and chronic kidney disease were independent risk factors for mortality in streptococcal IE. Streptococcal species did not affect mortality. 결론: Our study suggests significant differences in the prevalence of IE in streptococcal BSI according to the species, although species did not affect mortality in streptococcal IE. [ABSTRACT FROM AUTHOR]

배경: The sequence type 72 (ST72) is the predominant community-associated methicillin-resistant Staphylococcus aureus (MRSA) genotype in South Korea, replacing hospital clones as well as the community. During this change, we assessed the clinical characteristics of methicillin-susceptible and methicillin-resistant ST72 isolates causing bacteremia for better understanding of ST72 S. aureus in South Korea. 방법: We retrospectively collected data on patients with S. aureus bacteremia (SAB) who were admitted at a tertiary hospital in South Korea between March 2007 and December 2018. The ST72 isolates were identified by multilocus sequence typing (MLST). The clinical characteristics and outcomes of patients with methicillin-susceptible ST72 and those with methicillin-resistant ST72 were compared. 결과: A total 442 patients with ST72 SAB were identified, of which 157 (35.5%) were infected with methicillin-susceptible S. aureus (MSSA) and 285 (64.5%) were infected with MRSA. Community-onset infections were higher in the MSSA group compared to the MRSA group (20.4% vs. 10.2%, p=0.004), but the majority of infections occurred in healthcare-associated settings in both groups. MRSA isolates were likely to have multi-drug resistance and higher vancomycin MIC relative to the MSSA isolates. The main infection foci, infection severity, and bacteremic duration were not significantly different between the two groups. The 90-day SAB relapse was more common in the MRSA group than MSSA group (4.9% vs. 0.6%, P=0.04), while the 90-day mortality was comparable between the two groups (23.9% vs. 28.0%, P=0.39). 결론: In this study, a significant number of ST72 MSSA and ST72 MRSA infection occurred in hospital and healthcare settings. The 90-day recurrence rate was higher in methicillin-resistant ST72 infection than in methicillin-susceptible ST72 infection but there was no significant differences in type of main infection focus, presence of persistent bacteremia, and 90-day mortality. [ABSTRACT FROM AUTHOR]