Identifi cation of the Underlying Genetic Factors of Skin Aging in a Korean Population Study.

Genetic polymorphisms may affect the molecular mechanisms underlying determination of skin type. So far, several genetic studies have been reported; however, very few studies have been conducted to examine the relationship between genotype and skin phenotypes. In this study, the genome sequences of individuals tested for five cosmetic characteristics (wrinkles, moisture content, pigmentation, oil content, and ensitivity) were determined, and we also conducted five genome-wide association studies (GWASs) to identify predictive markers. Some single-nucleotide polymorphisms (SNPs) within those genes were more frequent in individuals exhibiting stronger traits. GWASs revealed that two genome-wide significant SNPs within FCRL5 and OCA2 genes were associated with wrinkles and pigmentation, respectively (p < 5 × 10-8), and that genomewide SNPs in 21 genes (wrinkles: FCRL5, REEP3, ADSS, and SPTLC1; moisture: TBX4, TRPM3, CEMIP2, CTSH, and TTC39C; pigmentation: OCA2, NCLN, TNS1, CDC42BPA, HS3ST4, and UNCX; oil: SYN2, CNDP1, GAS6, INSR, and TNFRSF19; and sensitivity: CREB5) might be associated with five skin phenotypes. Among these, a genome-wide significant SNP (rs117381658) and the SNP located downstream of FCRL5, which encodes a member of the immunoglobulin receptor family, were associated with an increased risk of wrinkles (p = 1.52 × 10-8). The other genome-wide significant SNP (rs74653330) was associated with a decreased risk of pigmentation (p = 1.04 × 10-8), which is located in the coding region of OCA2 that encodes for a transporter of melanin. Our study reports genetic factors associated with skin cosmetology parameters in the Korean population. We hope our findings will provide a foundation for further genetic and molecular studies related to custom cosmetics. Based on these findings, the industry will be able to provide consumers with ingredients capable of palliating the lack of function associated in genes with SNPs.

Phenotypic changes of methicillin-resistant Staphylococcus aureus during vancomycin therapy for persistent bacteraemia and related clinical outcome.

Persistent bacteraemia (PB) due to methicillin-resistant Staphylococcus aureus (MRSA) that fails to respond to glycopeptide therapy is a well-documented clinical problem. There are limited data on changes in agr functionality, vancomycin susceptibility and heteroresistance during MRSA PB. Thus, the frequency of these changes and their clinical significance remain unclear. Only patients with MRSA PB (≥7 days) from a prospective cohort of S. aureus bacteraemia were included. We collected isogenic paired strains and compared vancomycin MIC, vancomycin heteroresistance, and agr functionality between initial and final blood isolates. We also assessed the clinical outcome. A total of 49 patients had MRSA PB over 22 months. Bacteraemia persisted for a median of 13 days and most patients (98%) received glycopeptide as initial therapy. Among 49 isogenic pairs, only one pair showed a vancomycin MIC increase ≥2-fold by broth microdilution method, and only seven (14%) by E-test. Significant portions of initial isolates had vancomycin heteroresistance (49%) and agr dysfunction (76%). Development of vancomycin heteroresistance during PB occurred in four (16%) among 25 initial vancomycin-susceptible isolates, and acquisition of agr dysfunction occurred in two (16%) among 12 initial agr-functional isolates. Changes in the opposite direction occasionally occurred. These phenotypic changes during PB were not associated with mortality, whereas agr dysfunction of the initial isolates was significantly associated with mortality. During MRSA PB, phenotypic changes of MRSA isolates occurred occasionally under prolonged vancomycin exposure but were not significantly associated with clinical outcome. In contrast, initial agr dysfunction could be a predictor for mortality in MRSA PB.

Emergence of Panton-Valentine leucocidin-positive ST8-methicillin-resistant Staphylococcus aureus (USA300 clone) in Korea causing healthcare-associated and hospital-acquired bacteraemia.

Panton-Valentine leucocidin (PVL)-positive sequence type (ST)8-MRSA-SCCmec IVa (USA300) is the epidemic strain of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in North America. USA300 is extremely rare in South Korea, and PVL-negative ST72 SCCmec type IVc is the predominant CA-MRSA clone. In a multicentre, prospective cohort study of S. aureus bacteraemia, we identified PVL-positive ST8-MRSA isolates by performing multilocus sequence typing and PCR for PVL. We analyzed the clinical characteristics of patients with PVL-positive ST8-MRSA bacteraemia, and performed SCCmec, spa, and agr typing, PCR for arginine catabolic mobile element (ACME), virulence gene profiling, and pulsed-field gel electrophoresis (PFGE). Among a total of 818 MRSA isolates, we identified ten isolates of PVL-positive ST8-MRSA (USA300) (3 from Hospital D, 4 from Hospital G, and 3 from Hospital A), all of which involved exclusively healthcare-associated (5 isolates) and hospital-acquired bacteraemia (5 isolates). This strain accounted for 8~10 % of the hospital-acquired MRSA bacteraemia in Hospitals D and G. Bacteraemia of unknown origin was the most common type of infection followed by pneumonia. All the isolates were SCCmec type IVa, spa type t008, and agr group I. Eight of the isolates harboured ACME. In a PFGE analysis, four isolates were identical to the USA300 control strain, five differed by a single band, and the remaining one differed by two bands. All the isolates were pulsed-field type USA300. This is the first report of healthcare-associated and hospital-acquired bacteraemia caused by USA300 in South Korea. USA300 seems to be an emerging hospital clone in this country.

Incidence and differential characteristics of culture-negative fever following pancreas transplantation with anti-thymocyte globulin induction.

BACKGROUND: Limited data are available on the incidence and characteristics of culture-negative fever following pancreas transplantation (PTx) with anti-thymocyte globulin (ATG) induction. Our study aims to better define the features of culture-negative fever, so it can be delineated from infectious fever, hopefully helping clinicians to guide antibiotic therapy in this high-risk patient population. METHODS: We performed a retrospective cohort study of postoperative fever among 198 consecutive patients undergoing PTx at our center between August 1, 2004 and December 31, 2014. Fever was classified as culture-negative if there was neither a positive culture nor a documented clinical diagnosis of infection. RESULTS: Fever was identified in 113 patients; 66 were deemed to be infectious, 39 were culture-negative, and 8 were indeterminate. High body mass index of recipient (odds ratio 1.87, 95% confidence interval: 1.15-3.03, P = 0.011) was a significant factor associated with culture-negative fever in multivariate analysis. No patients with culture-negative fever were diagnosed with infiltrates or effusion on chest radiography. In addition, an increase in white blood cell count, C-reactive protein, and serum amylase was less prominent in culture-negative fever. Culture-negative fever developed most frequently at postoperative 7 or 14 days, showing a biphasic curve. CONCLUSION: Culture-negative fever develops in a substantial proportion of patients early after PTx. The awareness of the possibility and clinical features of post-transplant culture-negative fever might help clinicians to guide antibiotic therapy in this high-risk patient population, especially following ATG induction and early steroid withdrawal.

Fatal scedosporiosis in multiple solid organ allografts transmitted from a nearly-drowned donor.

Scedosporium spp. is the most common mold infection in pneumonia resulting from near-drowning. Three fatal scedosporiosis cases developed after solid organ transplantation, probably transmitted from the nearly-drowned donor. One heart transplant recipient and two kidney transplant recipients developed fatal scedosporiosis following deceased donor transplantation from the same donor, a nearly-drowned victim of a suicide attempt. Genotypically, indistinguishable strains of Scedosporium auratiacum were recovered from the three recipients. Two liver transplant recipients from the same donor received prophylactic voriconazole without any subsequent signs of infection. To determine the safety of donation from nearly-drowned donors, a national traceback investigation was also performed of the causes of deaths in all transplant recipients who received organs from drowned donors between 2001 and 2013. Over 13 years, 2600 deceased donor transplants were performed in Korea. Among these 2600 deceased donor transplants, 27 (1%) victims of drowning donated their organs. From these 27 donors, 84 patients received organ transplants and 18 died, including the above three. We found no microbiologic evidence of invasive mold transmission from the nearly-drowned donors to the other 15 recipients. Although disseminated infection in the donor could not be demonstrated by culture, undiagnosed disseminated donor infection and transmission of Scedosporium spp. should be considered in near-drowning events.

Prevalence of blaZ gene types and the cefazolin inoculum effect among methicillin-susceptible Staphylococcus aureus blood isolates and their association with multilocus sequence types and clinical outcome.

Cefazolin treatment failures have been described for bacteraemia caused by methicillin-susceptible Staphylococcus aureus (MSSA) with type A ß-lactamase and inoculum effect (InE). We investigated the prevalence of blaZ (ß-lactamase) gene types and a cefazolin InE among MSSA blood isolates in South Korea and evaluated their association with specific genotypes. The clinical impact of the cefazolin InE was also evaluated. A total of 220 MSSA isolates were collected from a prospective cohort study of S. aureus bacteraemia. A pronounced InE with cefazolin was defined as a ≥4-fold increase in the minimum inhibitory concentration (MIC) between a standard and high inoculum, resulting in a non-susceptible MIC. Sequencing of blaZ and multilocus sequence typing (MLST) were performed. Clinical outcomes were assessed in 77 patients treated with cefazolin. The blaZ gene was detected in 92 % of the 220 MSSA isolates. Type C ß-lactamase was the most common (53 %), followed by type B (20 %) and type A (17 %). Certain genotypes were significantly associated with specific ß-lactamase types (notably, ST30 and type A ß-lactamase). A pronounced cefazolin InE was observed in 13 % of isolates. Most of these (79 %) expressed type A ß-lactamase and ST30 was the predominant (55 %) clone amongst them. Cefazolin treatment failure was not observed in patients infected with strains exhibiting a pronounced InE. These strains had no impact on other clinical outcomes. In conclusion, the prevalence of a pronounced InE with cefazolin could be dependent upon distributions of MSSA genotypes. Cefazolin can likely be used for the treatment of MSSA bacteraemia (except endocarditis), without consideration of an InE.

Comparison of the clinical characteristics of Mycobacterium tuberculosis and nontuberculous mycobacteria patients with joint involvement.

Nontuberculous mycobacteria (NTM) joint involvement is rare. However, the incidence of NTM disease is increasing and it is difficult to distinguish NTM from Mycobacterium tuberculosis (MTB). Here, the clinical characteristics of NTM joint involvement were compared with those of MTB. Distal joint involvement and precipitating factors were significantly more frequent for NTM joint infections. Because pathologic findings of NTM and MTB were similar, microbiological investigations are needed.

Cytomegalovirus infection after acute rejection therapy in seropositive kidney transplant recipients.

BACKGROUND: Acute rejection (AR) after solid organ transplantation has been known to be a risk factor for cytomegalovirus (CMV) infection. However, data regarding the risk for CMV infection during and after anti-rejection therapy are limited. This study investigated whether the risk of CMV infection and disease within 6 months of kidney transplantation (KT) increases in CMV-seropositive KT recipients who develop AR. METHODS: A total of 992 seropositive KT recipients, including 75 patients (8%) who developed AR within 6 months after KT and 917 patients (92%) who did not, were recruited between May 2007 and April 2012. RESULTS: No significant difference was found in the incidence of CMV infection between the groups (AR group, 13% [10/75] vs. non-AR group, 10% [92/917], P = 0.37). The number of KT recipients in each group receiving preemptive therapy for CMV was similar (5% [4/75] vs. 6% [53/917], P > 0.99). While the incidence of CMV syndrome was comparable (0% [0/75] vs. 1% [12/917], P > 0.99), the incidence of tissue-invasive CMV disease (8% [6/75] vs. 3% [27/917], P = 0.04), particularly gastrointestinal CMV disease, was significantly greater in patients who experienced AR. No CMV-related mortality occurred in either group. AR (odds ratio, 2.81; 95% confidence interval, 1.08-7.29; P = 0.03) was an independent risk factor for tissue-invasive CMV disease within 6 months of KT. CONCLUSIONS: A high index of suspicion and active evaluation for tissue-invasive CMV disease in KT recipients suffering AR may be necessary to ensure appropriate treatment.

The impact of discontinuing single-room isolation of patients with vancomycin-resistant enterococci: a quasi-experimental single-centre study in South Korea.

OBJECTIVES: There is limited data on the effects of discontinuing single-room isolation while maintaining contact precautions, such as the use of gowns and gloves. In April 2021, our hospital ceased single-room isolation for patients with vancomycin-resistant enterococci (VRE) because of single-room unavailability. This study assessed the impact of this policy by examining the incidence of hospital-acquired VRE bloodstream infections (HA-VRE BSI). METHODS: This retrospective quasi-experimental study was conducted at a tertiary-care hospital in Seoul, South Korea. Time-series analysis was used to evaluate HA-VRE BSI incidence at the hospital level and in the haematology unit before (phase 1) and after (phase 2) the policy change. RESULTS: At the hospital level, HA-VRE BSI incidence level (VRE BSI per 1000 patient-days per month) and trend did not change significantly between phase 1 and phase 2 (coefficient -0.015, 95% confidence interval (CI): -0.053 to 0.023, P=0.45 and 0.000, 95% CI: -0.002 to 0.002, P=0.84, respectively). Similarly, HA-VRE BSI incidence level and trend in the haematology unit (-0.285, 95% CI: -0.618 to 0.048, P=0.09 and -0.018, 95% CI: -0.036 to 0.000, P = 0.054, respectively) did not change significantly across the two phases. CONCLUSIONS: Discontinuing single-room isolation of VRE-colonized or infected patients was not associated with an increase in the incidence of VRE BSI at the hospital level or among high-risk patients in the haematology unit. Horizontal intervention for multi-drug-resistant organisms, including measures such as enhanced hand hygiene and environmental cleaning, may be more effective at preventing VRE transmission.

agr Dysfunction and persistent methicillin-resistant Staphylococcus aureus bacteremia in patients with removed eradicable foci.

PURPOSE: Persistent Staphylococcus aureus bacteremia (SAB) has been observed in patients with eradicated foci, but there are few studies of the risk factors and clinical outcomes of persistent bacteremia. This study determined the risk factors for persistent methicillin-resistant S. aureus (MRSA) bacteremia in patients without retained eradicable foci, including genotypic characteristics. METHODS: All adult SAB patients were investigated between 2008 and 2010. Persistent bacteremia was defined as bacteremia lasting >7 days after treatment and patients were monitored prospectively. The study included patients without retained eradicable foci, e.g., removed prosthetic devices and intravenous catheters removed after diagnosis, and those without metastatic infections. RESULTS: Persistent bacteremia occurred in 36 % (31/87) SAB patients with eradicated foci. There were no significant differences in successful defervescence (2.0 vs. 2.0 days, P = 0.55) and total length of hospital stay after bacteremia in the persistent bacteremia group and resolved bacteremia group (P = 0.32). The difference in MRSA bacteremia-related 30-day mortality with persistent bacteremia and resolved bacteremia was not significant (P = 0.12). However, agr dysfunction was higher in persistent bacteremia patients (94 %) than those with resolved bacteremia (75 %, P = 0.03). Multivariate analysis using a logistic regression model found that only agr dysfunction [odds ratio (OR) 4.83, 95 % confidence interval (CI) 1.02-22.89, P = 0.04] was an independent risk factor for persistent bacteremia. CONCLUSIONS: This study suggests that persistent bacteremia with eradicated foci might not adversely affect the outcome for MRSA bacteremia patients. agr dysfunction in S. aureus was significantly associated with persistent bacteremia.

Risk factors for false-negative results of T-SPOT.TB and tuberculin skin test in extrapulmonary tuberculosis.

PURPOSE: T-SPOT.TB, a recently developed T cell-based assay, has shown promise in diagnosing extrapulmonary tuberculosis (EPTB). However, a limited number of reports have compared the risk factors for false-negative results of tuberculin skin tests (TSTs) and T-SPOT.TB assays in patients with EPTB. We, thus, conducted a prospective, blinded, observational study to evaluate the risk factors for false-negative T-SPOT.TB and TST results in patients with EPTB. METHODS: Between April 2008 and November 2011, all adult patients with suspected EPTB were prospectively enrolled at Asan Medical Center, Seoul, South Korea (an intermediate TB-burden country). Only patients with confirmed and probable EPTB who underwent TST and T-SPOT.TB were included in the final analysis. RESULTS: Of the 324 patients who underwent both TST and T-SPOT.TB testing, 128 patients with 96 (75 %) culture- or polymerase chain reaction (PCR)-confirmed and 32 (25 %) probable EPTB were finally analyzed. T-SPOT.TB assays were less likely to yield false-negative results than TSTs [17 % (22/128) vs. 54 % (69/128), p < 0.001]. In a multivariate analysis, miliary TB was associated with false-negative TSTs [odds ratio (OR) = 5.3; 95 % confidence interval (CI) 1.7-16.1], while immunosuppression showed a trend toward false-negative TSTs (OR = 2.5; 95 % CI 0.9-6.8). Conversely, lymph node TB (OR = 0.2; 95 % CI 0.1-0.5) and skeletal TB (OR = 0.2; 95 % CI 0.1-0.5) were associated with true-positive TST results. The only risk factor for false-negative T-SPOT.TB results was TB meningitis (OR = 2.6; 95 % CI 1.0-6.6). CONCLUSIONS: Our findings suggest that T-SPOT.TB has a better sensitivity to diagnose EPTB than TST, especially in patients with immunosuppression or miliary TB.

Microbiological and clinical characteristics of bacteraemia caused by the hypermucoviscosity phenotype of Klebsiella pneumoniae in Korea.

Hypermucoviscous (HV) isolates of Klebsiella pneumoniae have been linked to virulence potential in experimental infections. We examined 33 isolates of K. pneumoniae from patients with bacteraemia for the HV phenotype on agar culture, and determined their virulence potential by screening for capsular (K) serotype by polymerase chain reaction and the presence of seven virulence factor genes. Fourteen (42·4%) isolates expressed the HV phenotype and 11 of these were serotype K1 or K2; these serotypes were not identified in HV-negative isolates. The genes rmpA, rmpA2, aerobactin, wabG and allS were significantly more frequent in HV than non-HV isolates. Multilocus sequence typing identified 21 sequence types (ST), eight of which were found in HV-positive isolates and the clonal relatedness of isolates of the most frequent types (ST23 and ST11) from different hospitals was confirmed by pulsed-field gel electrophoresis. The HV phenotype was more associated with community-acquired infection with a lower frequency of fatal underlying illness, but with significantly more focal infections, notably liver abscesses. Clinicians should be aware of such clinical impacts of the HV phenotype.

Association between a functional polymorphism in Toll-like receptor 3 and chronic hepatitis C in liver transplant recipients.

BACKGROUND: Toll-like receptor 3 (TLR3) is implicated in the pathogenesis of viral diseases owing to its ability to recognize viral double-stranded RNA. We hypothesized that single nucleotide polymorphism (SNP) in TLR3 gene that impairs the function of the protein-receptor influences the outcome of hepatitis C virus (HCV) infection after liver transplantation. METHODS: The clinical characteristics of 611 liver recipients (HCV-infected: n = 153, non-HCV-infected: n = 458) were assessed to investigate the impact of TLR3 L412F SNP on transplant outcomes. RESULTS: TLR3 L412F is common, and it was significantly more prevalent among the HCV-infected cohort (57.5% vs. 45.2%, P = 0.008). In a multivariate analysis, TLR3 L412F was significantly associated with chronic hepatitis C (odds ratio: 1.73, 95% confidence interval [CI]: 1.13-2.65, P = 0.01). In an analysis that compared HCV-infected patients with wild-type versus TLR3 L412F, a marginally higher rate of allograft failure and mortality was observed in the TLR3 L412F group (44.3% vs. 30.8%, P = 0.09). However, in a multivariate analysis, only donor age was significantly associated with allograft failure and mortality (relative risk: 1.04, 95% CI: 1.007-1.06, P = 0.02). CONCLUSION: TLR3 L412F is significantly common in HCV-infected liver recipients, and may be associated with worse outcomes. However, larger studies are needed to determine its significant association with allograft failure and mortality after liver transplantation for chronic hepatitis C.

Comparison of the QuantiFERON-TB Gold In-Tube test with the tuberculin skin test for detecting latent tuberculosis infection prior to hematopoietic stem cell transplantation.

A total of 244 patients including 100 (41%) autologous hematopoietic stem cell transplant (HCT) recipients and 144 (59%) allogeneic HCT recipients were enrolled over a 28-month period. During the study period, no prophylaxis for latent tuberculosis (TB) infection was administrated. Of these, 201 (82%) had Bacillus Calmette-Guérin (BCG) scars or prior histories of BCG vaccination. The tuberculin skin test (TST) and the QuantiFERON-TB Gold In-Tube (QFT-GIT) test were performed simultaneously in all 244 patients. TST indurations were ≥ 5 mm in 39 of these patients (15%), and in 25 (10%) indurations were ≥ 10 mm. In addition, 40 (16%) had positive QFT-GIT outcomes, and 34 (14%) indeterminate outcomes. If the 34 patients with indeterminate QFT-GIT results were excluded from the overall agreement analysis, the agreement between the TST results (induration size ≥ 5 mm) and the QFT-GIT results in the 210 patients with clear QFT results was poor (κ = 0.08, 95% confidence interval [CI] -0.06 to 0.24), as it was for the patients with indurations ≥ 10 mm (κ = 0.15, 95% CI -0.004 to 0.31). During follow up, 2 patients developed TB after HCT. The incidence of TB in the patients with positive QFT-GIT outcomes was 2.80 per 100 person-years (95% CI 0.07-15.81), whereas among those with positive TST (≥ 5 mm) results, it was 0 per 100 person-years (95% CI 0-8.00). However, this finding should be cautiously interpreted because of the relatively short follow up and the fact that the sample size of the study cohort did not have adequate power. In conclusion, our data show that, although the frequencies of positive outcomes in the 2 TB screening tests were similar, the overall agreement between the TST and the QFT-GIT test was poor, regardless of BCG vaccination history.

Increased incidence of herpes zoster in the setting of cytomegalovirus preemptive therapy after kidney transplantation.

BACKGROUND: Herpes zoster (HZ) is a common infectious disease after kidney transplantation (KT). The incidence of HZ may increase during cytomegalovirus (CMV) preemptive therapy. We therefore evaluated the incidence, risk factors, and clinical outcomes of HZ after KT, according to the type of CMV prophylaxis used. METHODS: We retrospectively established a cohort of KT recipients who underwent transplantation from June 2008 to May 2010. Patients were categorized into 3 groups according to CMV prophylaxis regimen: Group A (preemptive therapy), Group B (universal prophylaxis <3 months), and Group C (universal prophylaxis >3 months). The incidence rate of HZ was compared in each group, and risk factors for HZ were identified. RESULTS: The incidence rate of HZ was 46.6 (95% confidence interval [CI] 31.4-66.5) per 1000 person-years. The incidence rate was higher in Group A than in Group C (80.0 vs. 13.0 per 1000 person-years; P = 0.001). Median onset time of HZ after KT was shorter in Group A than in Group B (0.9 vs. 9.9 months; P < 0.001) and Group C (0.9 vs. 14.8 months; P = 0.008). Post-herpetic neuralgia occurred in 7 patients (23%). No visceral involvement or death was related to HZ. By multivariate analysis, only female gender (corrected relative risk 1.59; 95% CI 1.09-2.00) was independently associated with HZ development. CONCLUSIONS: In the setting of CMV preemptive therapy, a differentiated varicella zoster virus-specific prophylaxis might be necessary for patients with HZ risk factors.

Impact of carbapenem-targeted antimicrobial stewardship interventions: an interrupted time-series analysis.

BACKGROUND: The development of carbapenem-resistant Gram-negative bacilli (CR-GNB) is largely favoured by indiscriminate and prolonged carbapenem use, which is a significant contributing factor. AIM: To evaluate the impact of two carbapenem antibiotic stewardship programme interventions on both carbapenem prescriptions and the clinical isolation rates of CR-GNBs, using interrupted time-series analysis. METHODS: A time-series analysis was performed using data for carbapenem usage from a tertiary hospital in South Korea from January 2017 to July 2022. Two carbapenem antibiotic stewardship programme interventions were implemented sequentially: (i) a prospective audit and feedback (PAF) from November 2018 to April 2020 (intervention 1), and (ii) preauthorization from May 2020 to August 2020 (intervention 2). Monthly carbapenem usage and incidence of CR-GNB before and after each intervention were compared using an autoregressive integrated moving average model. FINDINGS: Implementation of PAF resulted in a significant reduction in carbapenem consumption, followed by an additional decrease after the preauthorization was implemented. The incidence of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae increased after intervention 1, but there was a significant change from an increasing trend to a stationary trend after intervention 2. The incidence of carbapenem-resistant Pseudomonas aeruginosa, which had increased during the baseline period, became stationary after intervention 1. A significant decrease was observed in the incidence of carbapenem-resistant Acinetobacter baumannii during the implementation of intervention 1 and 2. CONCLUSION: This study emphasizes the importance of adopting comprehensive antibiotic management and rigorous infection control to prevent infections caused by antibiotic-resistant bacteria.

Risk of transmission of COVID-19 from healthcare workers returning to work after a 5-day isolation, and kinetics of shedding of viable SARS-CoV-2 variant B.1.1.529 (Omicron).

BACKGROUND: There have been limited data on the risk of onward transmission from individuals with Omicron variant infections who return to work after a 5-day isolation. AIM: To evaluate the risk of transmission from healthcare workers (HCWs) with Omicron variant who returned to work after a 5-day isolation and the viable-virus shedding kinetics. METHODS: This investigation was performed in a tertiary care hospital, Seoul, South Korea. In a secondary transmission study, we retrospectively reviewed the data of HCWs confirmed as COVID-19 from March 14th to April 3rd, 2022 in units with five or more COVID-19-infected HCWs per week. In the viral shedding kinetics study, HCWs with Omicron variant infection who agreed with daily saliva sampling were enrolled between February and March, 2022. FINDINGS: Of the 248 HCWs who were diagnosed with COVID-19 within 5 days of the return of an infected HCW, 18 (7%) had contact with the returned HCW within 1-5 days after their return. Of these, nine (4%) had an epidemiologic link other than with the returning HCW, and nine (4%) had contact with the returning HCW, without any other epidemiologic link. In the study of the kinetics of virus shedding (N = 32), the median time from symptom onset to negative conversion of viable virus was four days (95% confidence interval: 3-5). CONCLUSION: Our data suggest that the residual risk of virus transmission after 5 days of isolation following diagnosis or symptom onset is low.

Enterococcus avium bacteremia: a 12-year clinical experience with 53 patients.

Because Enterococcus avium is rarely isolated from blood cultures, little is known about the clinical features and outcomes of bacteremia caused by this organism, formerly called "group Q streptococcus". We retrospectively evaluated the clinical features and outcomes of patients with clinically significant bacteremia caused by E. avium presenting at a tertiary-care hospital in Korea between February 1997 and February 2009. We identified 53 patients over the 12-year period; of these, 27 (50.9%) had biliary and 13 (24.5%) had intra-abdominal E. avium infections. Thirty-six (67.9%) of the episodes were polymicrobial. Thirty-three (62.3%) episodes were nosocomial bloodstream infections and resistance to vancomycin was not observed. The crude mortality rate was 24.5% (13/53), and the E. avium bacteremia-related mortality rate was 11.3% (6/53). Multivariate analysis showed that underlying rapidly fatal or ultimately fatal disease (adjusted odds ratio [AOR], 6.92; 95% confidence interval [CI], 1.56-30.65; P = 0.011) and inadequate antimicrobial therapy (AOR, 7.29; CI, 1.27-41.93; P = 0.026) were independent risk factors for mortality. In summary, bacteremia due to E. avium was commonly of biliary or intraabdominal origin and was often associated with polymicrobial bacteremia. The crude mortality rate was considerable. Severe underlying conditions and inadequate antimicrobial therapy were significant and independent risk factors for crude patient mortality.

Clinical significance of Staphylococcus aureus bacteremia in patients with liver cirrhosis.

Patients with liver cirrhosis (LC) have impaired immunity and thus are predisposed to infections. Few studies have attempted to evaluate Staphylococcus aureus bacteremia (SAB) in LC patients. Therefore, this study prospectively evaluated the clinical characteristics and outcomes of 642 episodes of SAB from August 1, 2008 to September 31, 2010. Of 642 patients with SAB, 109 (17.0 %) were classified as LC patients whereas the remaining 533 (83.0 %) were classified as non-LC patients. The 30-day mortality rate of LC patients was significantly higher than that of patients with other diseases (32 % vs. 22 %, respectively; P = 0.047). The 30-day mortality rates of patients with MSSA bacteremia and MRSA bacteremia were not significantly different among LC patients (35.1 % with MSSA vs. 26.9 % with MRSA; P = 0.41). A univariate analysis of the 30-day mortality rate of LC patients with SAB for survivors and non-survivors showed that rapidly fatal or ultimately fatal according to the criteria of McCabe and Jackson (OR 5.0; 95 % CI 1.60-15.65), septic shock at initial presentation (OR 3.5; 95 % CI 1.18-10.39) and Child-Pugh class C (OR 2.8; 95 % CI 1.20-6.59) were associated with increased mortality. In contrast, the removal of the eradicable focus was associated with decreased mortality (OR 0.14; 95 % CI 0.04-0.52). Disease severity and liver dysfunction may be useful for predicting the prognosis of SAB in LC patients.

Clinical implication of extended-spectrum cephalosporin nonsusceptibility in Streptococcus pneumoniae meningitis.

The clinical implication of extended-spectrum cephalosporin (ESC) resistance has been unclear in patients with Streptococcus pneumoniae meningitis (SPM). We collected the clinical data of 120 patients with SPM in 12 hospitals of the Republic of Korea. The clinical characteristics and outcomes of 23 ESC-nonsusceptible SPM episodes were compared to those of 97 ESC-susceptible episodes. Hospital acquisition, presence of other foci of pneumococcal infection, septic shock at initial presentation, or concomitant bacteremia were more commonly observed in ESC-nonsusceptible than ESC-susceptible SPM. Empiric antimicrobial therapy with vancomycin and ESC combination was very common in both groups. Although there was a tendency towards higher early fatality in ESC-nonsusceptible SPM (3-day mortality; 17.4 % vs. 4.4 %, p = 0.05), in-hospital mortality (26.1 % vs. 20.9 %, p = 0.59) and median length of hospital stay (20 days vs. 24 days, p = 0.34) did not differ between ESC-nonsusceptible and ESC-susceptible SPM.