Disease burden of bacteraemia with extended-spectrum beta-lactamase-producing and carbapenem-resistant Enterobacterales in Korea.

BACKGROUND: Despite the significant impact of multi-drug-resistant bacteraemia, especially extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) and carbapenem-resistant Enterobacterales (CRE), the burden of disease has not been investigated thoroughly. AIM: To evaluate the clinical outcomes and socio-economic burden of ESBL-E and CRE bacteraemia nationwide in the Republic of Korea. METHODS: A search was undertaken for all cases of ESBL-E and CRE bacteraemia and matched controls in 10 hospitals in the Republic of Korea over 6 months. Patients with ESBL-E or CRE bacteraemia were classified as the R group, and matched controls with antibiotic-susceptible bacteraemia and without infection were classified as the S and N groups, respectively. Patients' clinical data were collected, and the economic burden was estimated based on medical expenses, loss of productivity and total costs. FINDINGS: In total, 795 patients were identified, including 265 patients with ESBL-E or CRE bacteraemia and their matched controls. The mean total length of stay for patients with ESBL-E and CRE in the R group was 1.53 and 1.90 times that of patients in the S group, respectively. The 90-day mortality rates for ESBL-E in the R and S groups were 12.1% and 5.6%, respectively, and the corresponding figures for CRE were 28.6% and 12.0%. There were significant differences in the total costs between the R, S and N groups for both ESBL-E and CRE (ESBL-E: $11,151 vs $8712 vs $6063, P=0.004; CRE: $40,464 vs $8748 vs $7279, P=0.024). CONCLUSION: The clinical and economic burden imposed by ESBL-E or CRE bacteraemia was extremely high. These findings suggest that efforts to control resistant bacteraemia are necessary to reduce this burden.

Appropriateness of antibiotic use for patients with asymptomatic bacteriuria or urinary tract infection with positive urine culture: a retrospective observational multi-centre study in Korea.

BACKGROUND: Antibiotic resistance threatens public health worldwide, and inappropriate use of antibiotics is one of the main causes. AIM: To evaluate qualitative use of antibiotics in asymptomatic bacteriuria (ABU) and urinary tract infection (UTI). METHODS: Cases of positive urine culture (≥105 colony-forning units/mL) performed in inpatient, outpatient and emergency departments in April 2021 were screened in 26 hospitals in the Republic of Korea. The cases were classified as ABU, lower UTI and upper UTI. The appropriateness of antibiotic use was evaluated retrospectively by infectious disease specialists using quality indicators based on clinical guidelines for ABU and UTI. RESULTS: This study included a total of 2697 patients with ABU or UTI. The appropriateness of antibiotic use was assessed in 1157 patients with ABU, and in 677 and 863 patients with lower and upper UTI, respectively. Among the 1157 patients with ABU, 251 (22%) were prescribed antibiotics without appropriate indications. In 66 patients with ABU in which antibiotics were prescribed with appropriate indications, the duration was adequate in only 23 (34.8%) patients. The appropriateness of empirical and definite antibiotics was noted in 527 (77.8%) and 353 (68.0%) patients with lower UTI, and 745 (86.3%) and 583 (78.2%) patients with upper UTI, respectively. The duration of antibiotics was adequate in 321 (61.8%) patients with lower UTI and 576 (78.7%) patients with upper UTI. CONCLUSIONS: This nationwide qualitative assessment of antibiotic use in ABU and UTI revealed that antibiotics were often prescribed inappropriately, and the duration of antibiotics was unnecessarily prolonged.

Impact of COVID-19 pandemic on healthcare-associated infections at intensive care units in South Korea: data from the Korean National Healthcare-Associated Infections Surveillance System (KONIS).

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has influenced hospital infection control practices. AIM: To evaluate the impact of the COVID-19 pandemic on healthcare-associated infections (HAIs) in intensive care units (ICUs). METHODS: A retrospective analysis using data from the Korean National Healthcare-Associated Infections Surveillance System was conducted. Comparisons between incidence rates and micro-organism distributions of bloodstream infection (BSI), central line-associated bloodstream infections (CLABSI), catheter-associated urinary tract infection (CAUTI), and ventilator-associated pneumonia (VAP) before and during the COVID-19 pandemic were performed according to hospital size. FINDINGS: The incidence rate of BSI significantly decreased during the COVID-19 pandemic compared to the pre-COVID-19 period (1.38 vs 1.23 per 10,000 patient-days, relative change -11.5%; P < 0.001). The incidence rate of VAP (1.03 vs 0.81 per 1000 device-days, relative change -21.4%; P < 0.001) significantly decreased during the COVID-19 pandemic compared to the pre-COVID-19 period, whereas rates of CLABSI (2.30 vs 2.23 per 1000 device-days; P = 0.19) and CAUTI (1.26 vs 1.26 per 1000 device-days; P = 0.99) were similar between the two periods. The rates of BSI and CLABSI significantly increased during the COVID-19 pandemic compared to the pre-COVID-19 period in large-sized hospitals, whereas these rates significantly decreased in small-to-medium-sized hospitals. The rates of CAUTI and VAP significantly decreased in small-sized hospitals. There were no significant changing trends in the rates of multidrug-resistant pathogens isolated from patients with HAI between the two periods. CONCLUSION: The incidence rates of BSI and VAP in ICUs decreased during the COVID-19 pandemic compared to the pre-COVID-19 period. This decrease was mainly seen in small-to-medium-sized hospitals.

Phase II study of a trastuzumab biosimilar in combination with paclitaxel for HER2-positive recurrent or metastatic urothelial carcinoma: KCSG GU18-18.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) is a widely explored therapeutic target in solid tumors. We evaluated the efficacy and safety of trastuzumab-pkrb, a biosimilar of trastuzumab, in combination with paclitaxel, in HER2-positive recurrent or metastatic urothelial carcinoma (UC). PATIENTS AND METHODS: We enrolled 27 patients; they were administered a loading dose of 8 mg/kg trastuzumab-pkrb on day 1, followed by 6 mg/kg and 175 mg/m2 paclitaxel on day 1 every 3 weeks, intravenously. All patients received six cycles of the combination treatment and continued to receive trastuzumab-pkrb maintenance until disease progression, unacceptable toxicity, or for up to 2 years. HER2 positivity (based on immunohistochemistry analysis) was determined according to the 2013 American Society of Clinical Oncology /College of American Pathologists HER2 testing guidelines. The primary endpoint was objective response rate (ORR); the secondary endpoints were overall survival (OS), progression-free survival (PFS), and safety. RESULTS: Twenty-six patients were evaluated via primary endpoint analysis. The ORR was 48.1% (1 complete and 12 partial responses) and the duration of response was 6.9 months [95% confidence interval (CI) 4.4-9.3 months]. With a median follow-up of 10.5 months, the median PFS and OS were 8.4 months (95% CI 6.2-8.8 months) and 13.5 months (95% CI 9.8 months-not reached), respectively. The most common treatment-related adverse event (TRAE) of any grade was peripheral neuropathy (88.9%). The most common grade 3/4 TRAEs were neutropenia (25.9%), thrombocytopenia (7.4%), and anemia (7.4%). CONCLUSIONS: Trastuzumab-pkrb plus paclitaxel demonstrates promising efficacy with manageable toxicity profiles in patients with HER2-positive recurrent or metastatic UC.

Nickel, chromium and methyl methacrylate monomer release from orthopaedic functional appliances.

AIM: This study was purposed to evaluate release of nickel and chromium ions and methyl methacrylate (MMA) monomers from functional appliances and their possible health effects. MATERIALS AND METHODS: Study design: Twin-block appliances and Bionators were immersed in artificial saliva and kept in a thermal incubator. Control group was established as artificial saliva without appliances. Artificial saliva was analysed after 7 days, 30 days and 90 days. Inductively coupled plasma mass spectrometry and gas chromatography-mass spectrometry was used for detection of nickel and chromium ions and MMA monomers. MTT assays and cytokine array were performed. STATISTICS: One way ANOVA with Tukey test and Dunnett's T3 for post-hoc analysis was used for evaluation of time-dependent changes and independent t-test was used for evaluation of MTT assay results. RESULTS: The results revealed that metal ions and MMA monomers are released from the appliances. Metal ion detection pattern was irregular and could not be analysed. Twin-block group showed significantly larger amount of MMA release. MTT assay revealed statistically significant but minimally reduced cellular activity on Bionator and twin-block groups compared to control groups. Cytokine array showed no or less inflammatory cytokine release on Bionator and twin-block groups. CONCLUSION: MMA monomer release was confirmed but the cytotoxic effect of functional appliance material release is minimal or negligible. General toxicity of the functional appliance from the MMA monomer release is likely to be minimal or negligible.

Coagulopathy after snake envenomation in South Korea.

OBJECTIVE: This retrospective study investigated the nature and severity of venom-induced consumption coagulopathy (VICC) and determined the clotting factors involved in VICC in patients after envenomation by South Korea's snakes. Additionally, we studied the effectiveness of antivenom for the treatment of VICC after envenomation. METHODS: Included patients were divided into three groups according to the severity of VICC (no VICC, partial VICC, and complete VICC). Data, including changes in coagulation parameters during hospitalization and clotting factors at presentation, were collected and analyzed. RESULTS: One hundred nineteen patients who presented at our emergency department within 3 h after snake envenomation were included. VICC developed in 34 patients (27 patients with partial VICC and 7 patients with complete VICC). Two of 34 patients with VICC required blood transfusions. Five patients with complete VICC had an undetectable fibrinogen concentration at presentation. Three patients with complete VICC had an unmeasurable INR and aPTT within 24 h. The median times of the most extreme values were 10 h for INR, 12 h for aPTT, and 16 h for fibrinogen after presentation in the VICC group. The D-dimer concentration peaked at a median of 63.5 h after presentation. The activities of factors II and X were significantly reduced in the complete VICC group (factor II: 88 (84-99.3)% in the non-VICC group vs. 69 (49.5-83.5)% in the complete VICC group; factor X:94 (83-102) in the non-VICC group vs. 70 (66.5-79.8)% in the complete VICC group), while there was no difference in factor V activity at presentation. The time from bite to first antivenom administration did not correlate with the time course and most extreme concentrations for fibrinogen and D-dimer within the VICC groups. DISCUSSION AND CONCLUSION: VICC occurs in approximately one-quarter of snakebite patients in South Korea; however, VICC itself does not appear to lead to clinical deterioration. Fibrinogen is an early diagnostic maker for complete VICC. Clotting factors II and X are involved in VICC. Future investigations should explore the mechanism of VICC from Korean snakebites and the effect of antivenom on VICC.

The effect of myocardial injury on the clinical course of snake envenomation in South Korea.

CONTENT: This study investigated the incidence, progression and clinical course of myocardial injury-related snake envenomation in South Korea. In addition, this study evaluated whether antivenom guidelines are appropriate to control envenomation in patients with myocardial injury. METHODS: The study included 198 patients who received antivenom after a snakebite, and they were divided into two groups according to evidence of myocardial injury (defined as elevated troponin I or ischemic change on electrocardiogram) at presentation. Data including serial troponin I, echocardiogram/coronary angiogram findings, the clinical course, and treatment were collected and analyzed. RESULTS: The incidence of myocardial injury at presentation was 15.2%. The troponin I level was 0.11 (0.07-0.56) ng/ml at presentation and tended to decrease over 24 h. Echocardiograms revealed neither regional wall motion abnormalities nor left ventricular dysfunction in 15 of 17 patients, while two patients showed signs of coronary artery stenosis on echocardiograms and coronary angiograms. However, compared with patients without myocardial injury, patients with myocardial injury had a higher frequency of systemic envenomation complications, including bleeding, respiratory failure, hypotension, acute kidney injury, thrombocytopenia and venom-induced consumption coagulopathy (VICC). The patients with myocardial injury at presentation needed significantly more frequent and larger doses of antivenom than indicated by the initial severity of envenomation. Multivariate analysis showed that myocardial injury was associated with the need for additional antivenom administration after initial administration. DISCUSSION AND CONCLUSION: Myocardial injury is not uncommon after snake envenomation in Korea. Although myocardial injury itself seems to be benign, the clinical course of patients with myocardial injury is complicated, and myocardial injury is associated with the need for additional antivenom administration. The optimal use of antivenom to control envenomation in patents with myocardial injury after snake envenomation in South Korea should be established.

Effects of subinhibitory concentrations of chlorhexidine and mupirocin on biofilm formation in clinical meticillin-resistant Staphylococcus aureus.

BACKGROUND: The effects of subinhibitory concentrations (sub-MICs) of antibacterial agents on the biofilm-forming ability of Staphylococcus aureus require further study. AIM: To investigate the effects of sub-MICs of chlorhexidine and mupirocin on biofilm formation in clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates. METHODS: MRSA isolates were collected from patients with bloodstream infections at a tertiary care hospital. The basal level of biofilm formation and biofilm induction by sub-MICs of chlorhexidine and mupirocin were evaluated by measuring biofilm mass stained with Crystal Violet. FINDINGS: Of the 112 MRSA isolates tested, 63 (56.3%) and 44 (39.3%) belonged to sequence type (ST)5 and ST72 lineages, respectively, which are the predominant healthcare- and community-associated clones in South Korea. ST5 isolates were more likely to have chlorhexidine MIC ≥4 (73.0% vs 29.5%), resistance to mupirocin (23.8% vs 0%), agr dysfunction (73.0% vs 9.1%), and qacA/B gene (58.7% vs 2.3%) compared to ST72 isolates. The basal level of biofilm formation ability was frequently stronger in ST72 isolates compared to ST5 isolates (77.3% vs 12.7%). Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in 56.3% and 53.6%, respectively, of all isolates. Biofilm induction was more prevalent in ST5 isolates (85.7% for chlorhexidine, 69.8% for mupirocin) than in ST72 isolates (15.9% for chlorhexidine, 27.3% for mupirocin). CONCLUSION: Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in half of the clinical MRSA isolates. Our results suggest that ST5 MRSA biofilm can be induced together with some other bacterial virulent factors following exposure to chlorhexidine, which might confer a survival advantage to this clone in the healthcare environment.

The Association with rhegmatogenous retinal detachment and paediatric atopic dermatitis: a 12-year Nationwide Cohort Study.

PURPOSE: Historically, atopic dermatitis (AD) is associated with an increased risk of rhegmatogenous retinal detachment (RRD). However, uncertainty remained regarding the effect of AD itself and comorbidities (e.g., allergic diseases, cataract surgery) on RRD occurrence in a large, population-based paediatric population. PATIENTS AND METHODS: We analysed the 12-year National Health Insurance Service database (2002-2013) covering the entire Korean population to estimate the association between AD and RRD in people aged under 20 years. RESULTS: We identified 3142 RRD patients, and matched 18,852 controls (six controls to each RRD patient); therefore, we included 21,994 peoples under aged 20 years in the analyses. AD was more prevalent in the RRD group (329 patients, 10.47%) than the control group (1043 patients, 5.53%; P < 0.001), and so were severe AD (153 patients [4.87%] and 223 patients [1.18%], respectively; P < 0.001). In conditional logistic regression analysis, AD was associated with RRD (OR, 1.61; 95% CI, 1.93-1.87) even after adjusting for allergic conditions, connective tissue disease, uveitis, and cataract surgery. In addition, severity of AD was associated with an increased risk of RRD (OR for non-severe AD and severe AD, 1.26 [95% CI, 1.05-1.51] and 2.88 [95% CI, 2.25-3.68]). CONCLUSION: This study suggests that AD itself is a risk factor of RRD in children by showing the association between AD and RRD occurrence and the biologic gradient even after adjustment for known confounders including allergic conditions, uveitis, and cataract surgery.

Clinical impacts of delayed central venous catheter removal according to the severity of comorbidities in patients with candidaemia.

BACKGROUND: The effects of early central venous catheter (CVC) removal on the clinical outcomes of patients with candidaemia remain controversial. This study evaluated the impact of delayed CVC removal on mortality according to the severity of comorbidities in patients with candidaemia. METHODS: Patients with candidaemia in a tertiary care hospital between January 2010 and December 2017 were included retrospectively. The severity of comorbidities was classified as low [Charlson Comorbidity Index (CCI) score ≤3] or high (CCI score ≥4). Cases with removal of CVC >2 days after the onset of candidaemia or without CVC removal were classified as having delayed CVC removal. RESULTS: In total, 239 patients with candidaemia were included, excluding 18 who died within 2 days of onset of candidaemia. Of these, 149 had low CCI scores and 90 had high CCI scores. Septic shock [adjusted odds ratio (aOR)=9.5] and delayed CVC removal (aOR=4.7) were significantly associated with increased 30-day mortality, whereas Candida parapsilosis infection (aOR=0.2) and cerebrovascular disease (aOR=0.3) were associated with decreased 30-day mortality, in patients with low CCI scores. Septic shock (aOR=13.0) was the only risk factor for 30-day mortality in those with high CCI scores. Delayed CVC removal was associated with increased 30-day mortality in patients with low CCI scores (50.0% vs 20.3%; P=0.001), but not in those with high CCI scores (50.0% vs 47.9%; P=0.87). CONCLUSION: Early CVC removal may improve the survival of patients with candidaemia and low CCI scores, but no such protective effect was evident in those with high CCI scores.

Chlorhexidine sensitivity in staphylococci isolated from patients with central line-associated bloodstream infection.

Since 2011, 2% chlorhexidine in 70% isopropyl alcohol (2% chlorhexidine tincture) has been widely used in Korea. To investigate changes in chlorhexidine sensitivity of staphylococci causing central line-associated bloodstream infections, 264 blood culture isolates from adult patients treated in intensive care units of five university hospitals between 2008 and 2016 were analysed. We observed no significant changes in chlorhexidine minimum inhibitory and bactericidal concentrations, or in the prevalence of resistance-associated genes before and after introduction of 2% chlorhexidine tincture. Thus, there was no evidence of increased resistance to chlorhexidine in staphylococci causing central line-associated bloodstream infections.

Thermoelectric properties of dispersant-free semiconducting single-walled carbon nanotubes sorted by a flavin extraction method.

Semiconducting single-walled carbon nanotubes (s-SWNTs) were extracted from SWNT mixtures using a flavin derivative (FC12). We evaluated the thermoelectric properties of the s-SWNT sheets. Electrical conductivity, power factor and figure of merit values of the sheets were increased by two orders of magnitude after removing FC12 simply by dipping in dichloromethane.

Impact of antimicrobial treatment duration on outcome of Staphylococcus aureus bacteraemia: a cohort study.

OBJECTIVES: To assess the outcome of Staphylococcus aureus bacteraemia (SAB) according to factors associated with necessity for longer treatment in conjunction with the duration of treatment. METHODS: We prospectively collected the data of patients with SAB consecutively during 12 to 39 months from 11 hospitals. If multiple episodes of SAB occurred in one patient, only the first episode was enrolled. Factors associated with necessity for longer treatment were defined as follows: persistent bacteraemia, metastatic infection, prosthesis and endocarditis. If any of the factors were present, then the case was defined as longer antibiotic treatment warranted (LW) group; those without any factors were defined as shorter antibiotic treatment sufficient (SS) group. Poor outcome was defined as a composite of 90-day mortality or 30-day recurrence. Duration of antibiotic administration was classified as <14 or ≥14 days in the SS group and <28 or ≥28 days in the LW group. RESULTS: Among 2098 cases, the outcome was analysed in 1866 cases, of which 591 showed poor outcome. The SS group accounted for 964 cases and the LW group for 852. On multivariate analysis, age over 65 years, pneumonia, higher Sequential Organ Failure Assessment (SOFA) score and chronic liver diseases were risk factors for poor outcome. Administration of antibiotics less than the recommendation was associated with poor outcome, but this significance was observed only in the LW group (adjusted odds ratio = 1.68; 95% confidence interval, 1.00-2.83; p 0.05). CONCLUSIONS: Inappropriately short antibiotic treatment was associated with poor outcome in the LW group. Vigilant evaluation for risk factors to determine the duration of treatment may improve the outcome among patients with SAB.

Electrically controllable THz asymmetric split-loop resonator with an outer square loop based on VO2.

In this paper, we propose an asymmetric split-loop resonator with an outer square loop (ASLR-OSL) based on vanadium dioxide (VO2) which can actively control the transmission characteristics of a terahertz wave while maintaining a high quality factor of the asymmetric split-loop resonator (ASLR) by adding an outer square loop. The proposed ASLR-OSL demonstrated transmission characteristics similar to those of ASLR, and the transmission characteristics of ASLR-OSL were successfully controlled by directly applying a bias voltage. These results show a simple method for imposing active properties on a common metamaterial having a high quality factor by adding a loop structure.

Allergen-specific immunotherapy induces regulatory T cells in an atopic dermatitis mouse model.

BACKGROUND: Several studies have demonstrated that allergen-specific immunotherapy (SIT) can be an effective treatment for atopic dermatitis (AD). However, there is no relevant mouse model to investigate the mechanism and validate the novel modality of SIT in AD. METHODS: NC/Nga mice with induced AD-like skin lesions received a subcutaneous injection of SIT (an extract of the house dust mite Dermatophagoides farinae [DfE]) or placebo for 5 weeks). Clinical and histological improvements of AD-like skin lesions were examined. The responses of local and systemic regulatory T (Treg) cells, natural killer (NK) cells, B cells, serum immunoglobulin, and T-cell cytokine response to DfE were evaluated to determine the underlying mechanism of the observed results. RESULTS: Specific immunotherapy significantly improved AD-like skin lesions. Histologically, SIT decreased epidermal thickness and reduced inflammatory cell infiltration, especially that of eosinophils. Concomitantly, SIT suppressed Th2 responses and induced local infiltration of Treg cells into the skin. Also, SIT induced the immunoglobulin G4 and attenuated allergen-specific immunoglobulin E. Furthermore, SIT induced local and systemic IL-10-producing Treg cells and regulatory NK cells. CONCLUSION: We established a SIT model on AD mice and showed that our model correlates well with previous reports about SIT-treated patients. Also, we revealed NK cells as another possible resource of IL-10 in SIT. Based on our results, we suggest our SIT model as a useful tool to investigate mechanism of action of SIT and to validate the efficacy of new SIT modalities for the treatment of AD.

Sensitization to various minor house dust mite allergens is greater in patients with atopic dermatitis than in those with respiratory allergic disease.

BACKGROUND: Various allergenic proteins are produced by house dust mites (HDM). However, the allergenicity and clinical implications of these allergens are unknown. OBJECTIVE: The purpose of this study was to identify allergens in Dermatophagoides farinae and elucidate the sensitization profiles to these in Korean patients suffering from respiratory (allergic rhinitis and/or asthma) and atopic dermatitis symptoms. METHODS: IgE reactivities in sera from 160 HDM allergy patients were analysed by one- and two-dimensional gel electrophoresis and immunoblotting. IgE-reactive components were identified by liquid chromatography-coupled electrospray ionization-tandem mass spectrometry. Nine recombinant mite allergens (Der f 1, Der f 2, Der f 10, Der f 11, Der f 13, Der f 14, Der f 30, Der f 32 and Der f Alt a 10) were produced, and the IgE reactivity in sera to each was determined by ELISAs. RESULTS: Der f 1 and Der f 2 were recognized by IgE in serum samples from 88.1% and 78.1% of all patients, respectively. Patients with respiratory allergies were mainly sensitized to these major allergens, whereas patients with atopic dermatitis symptoms showed polysensitization to major and minor allergen components (including Der f 11, Der f 13, Der f 14, Der f 32 and Der f Alt a 10). CONCLUSIONS: Patients with respiratory allergic disease sensitize to major allergen components of HDM. Those with atopic dermatitis were sensitized to a broader range of minor allergen components of HDM (Der f 11, Der f 13, Der f 14, Der f 32 and Der f Alt a 10).

A modified-live porcine reproductive and respiratory syndrome virus (PRRSV)-1 vaccine protects late-term pregnancy gilts against heterologous PRRSV-1 but not PRRSV-2 challenge.

The objective of this study was to determine the efficacy of a commercially available porcine reproductive and respiratory syndrome virus (PRRSV)-1 modified-live virus (MLV) vaccine against PRRSV-1 and PRRSV-2 challenge in late-term pregnancy gilts. Gilts were vaccinated with the PRRSV-1 MLV vaccine at 4 weeks prior to breeding and then challenged intranasally with PRRSV-1 or PRRSV-2 at 93 days of gestation. After PRRSV-1 challenge, vaccinated pregnant gilts had a significantly longer gestation period, significantly higher numbers of live-born and weaned piglets and a significantly lower number of stillborn piglets at birth compared to unvaccinated pregnant gilts. No significant improvement in reproductive performance was observed between vaccinated and unvaccinated pregnant gilts following PRRSV-2 challenge. Vaccinated pregnant gilts also exhibited a significantly improved reproductive performance after challenge with PRRSV-1 compared to vaccinated pregnant gilts following PRRSV-2 challenge. The PRRSV-1 MLV vaccine was able to reduce PRRSV-1 but not PRRSV-2 viremia in pregnant gilts. Vaccinated gilts also showed a significantly higher number of PRRSV-1-specific IFN-γ-secreting cells (IFN-γ-SC) compared to PRRSV-2-specific IFN-γ-SC. The data presented here suggest that the vaccination of pregnant gilts with a PRRSV-1 MLV vaccine provides good protection against PRRSV-1 but only limited protection against PRRSV-2 challenge in late-term pregnancy gilts based on improvement of reproductive performance, reduction in viremia and induction of IFN-γ-SC.

Incidence of cephalosporin-induced anaphylaxis and clinical efficacy of screening intradermal tests with cephalosporins: A large multicenter retrospective cohort study.

BACKGROUND: Few studies have investigated the incidence of anaphylaxis induced by individual or structurally similar cephalosporins. The aims of the study were to assess the incidence of cephalosporin-induced anaphylaxis and evaluate the clinical efficacy of screening skin tests. METHODS: In this retrospective cohort study, we obtained information on total cephalosporin use and cephalosporin-induced anaphylaxis in intravenous cephalosporin recipients in 12 general hospitals between 2013 and 2015. Cephalosporins were divided into 4 groups according to similar side-chain structures. The incidence of cephalosporin-induced anaphylaxis was assessed for each cephalosporin, cephalosporin generation, and side-chain group. To verify the efficacy of screening intradermal tests (IDT) with cephalosporin, the 12 hospitals were assigned to the intervention or control group depending on whether they performed screening IDT before the administration of cephalosporins. RESULTS: We identified 76 cases of cephalosporin-induced anaphylaxis with 1 123 345 exposures to intravenous cephalosporins (6.8 per 100 000 exposures), and the incidence of fatal anaphylaxis by cephalosporin was 0.1 cases per 100 000 exposures. The highest incidences of anaphylaxis occurred in the ceftizoxime (13.0 cases per 100 000 exposures) and side-chain group 1 (cefepime, cefotaxime, ceftizoxime, ceftriaxone, and cefuroxime; 9.3 per 100 000). There was no case of anaphylaxis induced by cefoxitin, cefmetazole, cefminox, and cefotiam. The clinical effectiveness of routine screening IDT was not significant (P = .06). CONCLUSIONS: The incidence of cephalosporin-induced anaphylaxis differed according to individual drugs and side-chain structure. Screening IDT showed no clinical efficacy at a population level.

Clinical impact of delayed catheter removal for patients with central-venous-catheter-related Gram-negative bacteraemia.

BACKGROUND: Gram-negative bacteria are increasingly the cause of catheter-related bloodstream infection (CRBSI), and the prevalence of multi-drug-resistant strains is rising rapidly. This study evaluated the impact of delayed central venous catheter (CVC) removal on clinical outcomes in patients with Gram-negative CRBSI. METHODS: Between January 2007 and December 2016, patients with Gram-negative bacteraemia and CVC placement, from two tertiary care hospitals, were included retrospectively. Cases with CVC removal more than three days after onset of bacteraemia or without CVC removal were classified as having delayed CVC removal. RESULTS: In total, 112 patients were included. Of these, 78 had CRBSI (43 definite and 35 probable) and 34 had Gram-negative bacteraemia from another source (non-CRBSI). Enterobacteriaceae were less common pathogens in patients with CRBSI than in patients with non-CRBSI (11.5% vs 41.3%; P<0.001). Delayed CVC removal was associated with increased 30-day mortality (40.5% vs 11.8%; P=0.01) in patients with Gram-negative CRBSI; this was not seen in patients with non-CRBSI (25.0% vs 14.3%; P>0.99). Delayed CVC removal [odds ratio (OR) 6.8], multi-drug-resistant (MDR) Gram-negative bacteraemia (OR 6.3) and chronic renal failure (OR 11.1) were associated with 30-day mortality in patients with CRBSI. The protective effect of early CVC removal on mortality was evident in the MDR group (48.3% vs 18.2%; P=0.03), but not in the non-MDR group (11.1% vs 0%; P=0.43). CONCLUSION: CVCs should be removed early to improve clinical outcomes in patients with Gram-negative CRBSI, especially in settings where MDR isolates are prevalent.

Comparative outcomes of cefazolin versus nafcillin for methicillin-susceptible Staphylococcus aureus bacteraemia: a prospective multicentre cohort study in Korea.

OBJECTIVES: No randomized controlled trials have evaluated the comparative outcomes of cefazolin versus nafcillin for methicillin-susceptible Staphylococcus aureus (MSSA) bacteraemia. METHODS: A prospective observational cohort study including all S. aureus bacteraemia was conducted at 10 hospitals. Patients (≥15 years) with MSSA bacteraemia who received cefazolin or nafcillin as definitive antibiotics were included. The rates of treatment failure (premature discontinuation of antibiotics because of adverse effects, switching of antibiotics because of clinical failure, all-cause mortality within 1 month, or recurrence) were compared between the cefazolin and nafcillin groups. Propensity score matching analyses were performed to balance the factors influencing the selection of antibiotics. RESULTS: Among the 242 included cases, the bones and joints (36.8%) were the most common sites of infection and 60.7% of the patients had sepsis. The overall treatment failure rate was 43.8% (106/242). All-cause mortality within 1 month was 6.2% (15/242). After propensity score matching, the treatment failure rate of cefazolin was lower than that of nafcillin (30.4% (24/79) vs. 49.4% (39/79), p 0.015) because of a higher rate of discontinuation caused by adverse events. When the data were limited to patients with sepsis, the treatment failure rates of both groups were not significantly different. Approximately 22% (24/110) of MSSA isolates exhibited a cefazolin-inoculum effect (CIE) that had significant impact on the failure rate and mortality of the cefazolin group. CONCLUSIONS: Cefazolin might be recommended as an adequate and better-tolerated treatment for MSSA bacteraemia in the absence of CIE.