Trends of antibiotic use at the end-of-life of cancer and non-cancer decedents: a nationwide population-based longitudinal study (2006-2018)

Objective

This study aimed to assess the actual burden of antibiotic use among end-of-life (EOL) patients in South Korea and to compare trends between cancer and non-cancer decedents.

Design

Population-based mortality follow-back study.

Setting

Data from the Korean National Health Insurance Database, covering the period from January1, 2006, to December 31, 2018, provided for research by the National Health Insurance Service (NHIS), were used.

Participants

All decedents from 2006 to 2018 were included and categorized as cancer decedents or non-cancer decedents.

Methods

Annual antibiotic consumption rates and prescription rates were calculated, and Poisson regression was used to estimate their trends.

Results

Overall antibiotic consumption rates decreased slightly among decedents in their final month with a less pronounced annual decrease rate among cancer decedents compared to non-cancer decedents (0.4% vs 2.3% per year, P <.001). Over the study period, although narrow spectrum antibiotics were used less, utilization and prescription of broad-spectrum antibiotics steadily increased, and prescription rates were higher in cancer decedents compared to non-cancer controls. Specifically, carbapenem prescription rates increased from 5.6% to 18.5%, (RR 1.087, 95% CI 1.085-1.088, P <.001) in cancer decedents and from 2.9% to 13.2% (RR 1.115, 95% CI 1.113-1.116, P <.001) in non-cancer decedents.

Conclusions

Our findings show that patients at the EOL, especially those with cancer, are increasingly and highly exposed to broad-spectrum antibiotics. Measures of antibiotic stewardship are required among this population.

Sodium Intake Estimation in Hospital Patients Using AI-Based Imaging: Prospective Pilot Study

BACKGROUND

Measurement of sodium intake in hospitalized patients is critical for their care. In this study, artificial intelligence (AI)-based imaging was performed to determine sodium intake in these patients.

OBJECTIVE

The applicability of a diet management system was evaluated using AI-based imaging to assess the sodium content of diets prescribed for hospitalized patients.

METHODS

Based on the information on the already investigated nutrients and quantity of food, consumed sodium was analyzed through photographs obtained before and after a meal. We used a hybrid model that first leveraged the capabilities of the You Only Look Once, version 4 (YOLOv4) architecture for the detection of food and dish areas in images. Following this initial detection, 2 distinct approaches were adopted for further classification: a custom ResNet-101 model and a hyperspectral imaging-based technique. These methodologies focused on accurate classification and estimation of the food quantity and sodium amount, respectively. The 24-hour urine sodium (UNa) value was measured as a reference for evaluating the sodium intake.

RESULTS

Results were analyzed using complete data from 25 participants out of the total 54 enrolled individuals. The median sodium intake calculated by the AI algorithm (AI-Na) was determined to be 2022.7 mg per day/person (adjusted by administered fluids). A significant correlation was observed between AI-Na and 24-hour UNa, while there was a notable disparity between them. A regression analysis, considering patient characteristics (eg, gender, age, renal function, the use of diuretics, and administered fluids) yielded a formula accounting for the interaction between AI-Na and 24-hour UNa. Consequently, it was concluded that AI-Na holds clinical significance in estimating salt intake for hospitalized patients using images without the need for 24-hour UNa measurements. The degree of correlation between AI-Na and 24-hour UNa was found to vary depending on the use of diuretics.

CONCLUSIONS

This study highlights the potential of AI-based imaging for determining sodium intake in hospitalized patients.

The Hospitalist-Oncologist co-ManagemEnt (HOME) system improves hospitalization outcomes of patients with cancer

BACKGROUND

The hospitalist system has been introduced to improve the quality and safety of inpatient care. As its effectiveness has been confirmed in previous studies, the hospitalist system is spreading in various fields. However, few studies have investigated the feasibility and value of hospitalist-led care of patients with cancer in terms of quality and safety measures. This study aimed to evaluate the efficacy of the Hospitalist-Oncologist co-ManagemEnt (HOME) system.

METHODS

Between January 1, 2019, and January 31, 2021, we analyzed 591 admissions before and 1068 admissions after the introduction of HOME system on January 1, 2020. We compared the length of stay and the types and frequencies of safety events between the conventional system and the HOME system, retrospectively. We also investigate rapid response system activation, cardiopulmonary resuscitation, unplanned intensive care unit transfer, all-cause in-hospital mortality, and 30-day re-admission or emergency department visits.

RESULTS

The average length of stay (15.9 days vs. 12.9 days, P < 0.001), frequency of safety events (5.6% vs. 2.8%, P = 0.006), rapid response system activation (7.3% vs. 2.2%, P < 0.001) were significantly reduced after the HOME system introduction. However, there was no statistical difference in frequencies of cardiopulomonary resuscitation and intensive care unit transfer, all-cause in-hospital morality, 30-day unplanned re-admission or emergency department visits.

CONCLUSIONS

The study suggests that the HOME system provides higher quality of care and safer environment compared to conventional oncologist-led team-based care, and the efficiency of the medical delivery system could be increased by reducing the hospitalization period without increase in 30-day unplanned re-admission.

Effect of Active Surgical Co-Management by Medical Hospitalists in Urology Inpatient Care: A Retrospective Cohort Study

PURPOSE

This study aimed to evaluate the use of active surgical co-management (SCM) by medical hospitalists for urology inpatient care.

MATERIALS AND METHODS

Since March 2019, a hospitalist-SCM program was implemented at a tertiary-care medical center, and a retrospective cohort study was conducted among co-managed urology inpatients. We assessed the clinical outcomes of urology inpatients who received SCM and compared passive SCM (co-management of patients by hospitalists only on request; March 2019 to June 2020) with active SCM (co-management of patients based on active screening by hospitalists; July 2020 to October 2021). We also evaluated the perceptions of patients who received SCM toward inpatient care quality, safety, and subjective satisfaction with inpatient care at discharge or when transferred to other wards.

RESULTS

We assessed 525 patients. Compared with the passive SCM group (n=205), patients in the active SCM group (n=320) required co-management for a significantly shorter duration (p=0.012) and tended to have a shorter length of stay at the urology ward (p=0.062) and less frequent unplanned readmissions within 30 days of discharge (p=0.095) while triggering significantly fewer events of rapid response team activation (p=0.002). No differences were found in the proportion of patients transferred to the intensive care unit, in-hospital mortality rates, or inpatient care questionnaire scores.

CONCLUSION

Active surveillance and co-management of urology inpatients by medical hospitalists can improve the quality and efficacy of inpatient care without compromising subjective inpatient satisfaction.

Impact of hospitalist care model on patient outcomes in acute medical unit: a retrospective cohort study

OBJECTIVE

To assess a newly introduced, hospitalist-run, acute medical unit (AMU) care model at a tertiary care hospital in the Republic of Korea.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care hospital in the Republic of Korea.

PARTICIPANTS

We evaluated 6391 medical inpatients admitted through the emergency department (ED) from 1 June 2016 to 31 May 2017.

INTERVENTIONS

The study compared multiple outcomes among medical inpatients from the ED between the non-hospitalist group and the AMU hospitalist group.

OUTCOME MEASURES

In-hospital mortality (IHM), intensive care unit (ICU) admission rate, hospital length of stay (LOS), ED-LOS and unscheduled readmission rates were defined as patient outcomes and compared between the two groups.

RESULTS

Compared with the non-hospitalist group, the AMU hospitalist group had lower IHM (OR: 0.43, p<0.001), a lower ICU admission rate (OR: 0.72, p=0.013), a shorter LOS (coefficient: -0.984, SE: 0.318; p=0.002) and a shorter ED-LOS (coefficient: -3.021, SE: 0.256; p<0.001). There were no significant differences in the 10-day or 30-day readmission rates (p=0.974, p=0.965, respectively).

CONCLUSIONS

The AMU hospitalist care model was associated with reductions in IHM, ICU admission rate, LOS and ED-LOS. These findings suggest that the AMU hospitalist care model has the potential to be adopted into other healthcare systems to improve care for patients with acute medical needs.

Antibiotic Prescription in Patients With Coronavirus Disease 2019: Analysis of National Health Insurance System Data in the Republic of Korea

BACKGROUND

Although coronavirus disease 2019 (COVID-19) is a viral infection, antibiotics are often prescribed due to concerns about accompanying bacterial infection. Therefore, we aimed to analyze the number of patients with COVID-19 who received antibiotic prescriptions, as well as factors that influenced antibiotics prescription, using the National Health Insurance System database.

METHODS

We retrospectively reviewed claims data for adults aged ≥ 19 years hospitalized for COVID-19 from December 1, 2019 to December 31, 2020. According to the National Institutes of Health guidelines for severity classification, we calculated the proportion of patients who received antibiotics and the number of days of therapy per 1,000 patient-days. Factors contributing to antibiotic use were determined using linear regression analysis. In addition, antibiotic prescription data for patients with influenza hospitalized from 2018 to 2021 were compared with those for patients with COVID-19, using an integrated database from Korea Disease Control and Prevention Agency-COVID19-National Health Insurance Service cohort (K-COV-N cohort), which was partially adjusted and obtained from October 2020 to December 2021.

RESULTS

Of the 55,228 patients, 46.6% were males, 55.9% were aged ≥ 50 years, and most patients (88.7%) had no underlying diseases. The majority (84.3%; n = 46,576) were classified as having mild-to-moderate illness, with 11.2% (n = 6,168) and 4.5% (n = 2,484) having severe and critical illness, respectively. Antibiotics were prescribed to 27.3% (n = 15,081) of the total study population, and to 73.8%, 87.6%, and 17.9% of patients with severe, critical, and mild-to-moderate illness, respectively. Fluoroquinolones were the most commonly prescribed antibiotics (15.1%; n = 8,348), followed by third-generation cephalosporins (10.4%; n = 5,729) and beta-lactam/beta-lactamase inhibitors (6.9%; n = 3,822). Older age, COVID-19 severity, and underlying medical conditions contributed significantly to antibiotic prescription requirement. The antibiotic use rate was higher in the influenza group (57.1%) than in the total COVID-19 patient group (21.2%), and higher in severe-to-critical COVID-19 cases (66.6%) than in influenza cases.

CONCLUSION

Although most patients with COVID-19 had mild to moderate illness, more than a quarter were prescribed antibiotics. Judicious use of antibiotics is necessary for patients with COVID-19, considering the severity of disease and risk of bacterial co-infection.

Anti-Alpha-Toxin Antibody Responses and Clinical Outcomes of Staphylococcus aureus Bacteremia

BACKGROUND

Alpha-toxin (AT), a major virulence factor of Staphylococcus aureus, is an important immunotherapeutic target to prevent or treat invasive S. aureus infections. Previous studies have suggested that anti-AT antibodies (Abs) may have a protective role against S. aureus bacteremia (SAB), but their function remains unclear. Therefore, we aimed to investigate the association between serum anti-AT Ab levels and clinical outcomes of SAB.

METHODS

Patients from a prospective SAB cohort at a tertiary-care medical center (n = 51) were enrolled in the study from July 2016 to January 2019. Patients without symptoms or signs of infection were enrolled as controls (n = 100). Blood samples were collected before the onset of SAB and at 2- and 4-weeks post-bacteremia. Anti-AT immunoglobin G (IgG) levels were measured using an enzyme-linked immunosorbent assay. All clinical S. aureus isolates were tested for the presence of hla using polymerase chain reaction.

RESULTS

Anti-AT IgG levels in patients with SAB before the onset of bacteremia did not differ significantly from those in non-infectious controls. Pre-bacteremic anti-AT IgG levels tended to be lower in patients with worse clinical outcomes (7-day mortality, persistent bacteremia, metastatic infection, septic shock), although the differences were not statistically significant. Patients who needed intensive care unit care had significantly lower anti-AT IgG levels at 2 weeks post-bacteremia (P = 0.020).

CONCLUSION

The study findings suggest that lower anti-AT Ab responses before and during SAB, reflective of immune dysfunction, are associated with more severe clinical presentations of infection.

Nationwide survey of internal medicine hospitalists in Korea: motivation and sustainability of a hospitalist career

Background/Aims

Although a management fee for hospitalist service was established in Korea, the number of hospitalists required for the system to run remains outmatched.

Methods

In January 2020 and February 2022, before and after the establishment of the hospitalist fee system respectively, cross-sectional online surveys were conducted among internal medicine board-certified hospitalists.

Results

There were 59 and 64 respondents in the 2020 and 2022 surveys, respectively. The percentage of respondents who cited financial benefits as a motive for becoming a hospitalist was higher in the 2022 survey than in the 2020 survey (34.4% vs. 10.2%; p = 0.001). The annual salary of respondents was also higher in the 2022 survey than in the 2020 survey (mean, 182.9 vs. 163.0 million in South Korean Won; p = 0.006). A total of 81.3% of the respondents were willing to continue a hospitalist career in the 2022 survey. In multivariate regression analysis, the possibility of being appointed as a professor was found to be an independent predictive factor of continuing a hospitalist career (odds ratio, 4.00; 95% confidence interval, 1.09-14.75; p = 0.037).

Conclusions

Since the establishment of the hospitalist fee system, monetary compensation has improved for hospitalists. The possibility of being appointed as a professor could predict long-term work as hospitalists.

1781. Antibiotic Prescription Trends of Patients with COVID-19: Analysis of National Health Insurance Data in Republic of Korea

Background

Although COVID-19 is a viral infection, it is known that antibiotics are often prescribed due to concerns about combined bacterial infection. Therefore, we aimed to analyze how many patients with COVID-19 received the antibiotic prescription as well as what kinds of factors contributed to it using the National Health Insurance database.

Methods

We retrospectively reviewed claims data for adults 19 years of age and older hospitalized for COVID-19 from December 1, 2019 to December 31, 2020. According to severity classification of the National Institutes of Health guidelines, we calculated not only the proportion of patients receiving antibiotics but also days of treatment per 1000 patient days. In addition, we investigated the factors contributing to antibiotic use by linear regression analysis.

Results

Of the 55,228 patients, 47% were male, 55% were older than 50 years of age, and most patients (89%) had no underlying diseases. The majority (84%, 46,576) were classified as having mild to moderate illness, with 11% (6,168) and 5% (2,484) having severe and critical, respectively. Antibiotics were prescribed in a total of 27% (15,081). While 74% of patients with severe illness and 88% of those with critical illness received antibiotic treatment, even 18% of mild to moderate cases were prescribed antibiotics. Fluoroquinolones were the most commonly prescribed antibiotics (8,348), followed by third generation cephalosporins (5,729) and beta-lactam/beta-lactamase inhibitors (3,822) as shown in Figure 1. Older age, severity of disease and underlying medical conditions contributed to overall prescription rates as well as days of antibiotic use significantly (Table 1).

Conclusion

Although most of COVID-19 patients had mild to moderate illness, more than a quarter were prescribed antibiotics. Judicious use of broad-spectrum antibiotics is necessary for COVID-19 patients, considering the severity of disease and the risk of bacterial co-infection.

Disclosures

All Authors: No reported disclosures.

Prevalence of and factors associated with inappropriate Clostridioides difficile testing in a teaching hospital in Korea

Background

Given the increasing incidence of Clostridioides difficile infections in Korea, there has been an increase in inappropriate testing for C. difficile, which has rendered overdiagnosis of asymptomatic colonisers common. We aimed to investigate the appropriateness of C. difficile testing and the related factors.

Methods

We retrospectively reviewed the medical records of patients who were admitted to a 1300-bed tertiary-care teaching hospital in Korea and were tested for C. difficile infection from September 2019 to November 2019. We performed logistic regression analysis to investigate factors related to inappropriate testing. Further, a survey was conducted on physicians to assess the knowledge and ordering patterns of C. difficile testing.

Results

We included 715 tests from 520 patients in the analysis. Testing was classified as hospital-onset and community-onset and subclassified as appropriate and inappropriate following an algorithmic method. Among the 715 tests, 576 (80.6%) and 139 (19.6%) tests were classified as hospital-onset and community-onset, respectively. Among the hospital-onset tests, 297 (52%) were considered inappropriate. The risk of inappropriate testing increased when C. difficile tests were conducted in the emergency room (OR 24.96; 95% CI 3.12–199.98) but decreased in intensive care units (OR 0.36, 95% CI 0.19–0.67). The survey was conducted on 61 physicians. Internal medicine physicians had significantly higher scores than non-internal medicine physicians (7.1 vs. 5.7, p = 0.001). The most frequently ordered combination of tests was toxin + glutamate dehydrogenase (47.5%), which was consistent with the ordered tests.

Conclusion

Almost half of the C. difficile tests were performed inappropriately. The patient being located in the emergency room and intensive care unit increased and decreased the risk of inappropriate testing, respectively. In a questionnaire survey, we showed that internal medicine physicians were more knowledgeable about C. difficile testing than non-internal medicine physicians. There is a need to implement the diagnostic stewardship for C. difficile, especially through educational interventions for emergency room and non-internal medicine physicians.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-022-01111-0.

Safety of macitentan for the treatment of pulmonary hypertension: Real‐world experience from the OPsumit® USers Registry (OPUS) and OPsumit® Historical USers cohort (OrPHeUS)

Macitentan is an oral endothelin receptor antagonist for the management of pulmonary arterial hypertension (PAH). The OPsumit® USers Registry (OPUS) and the OPsumit® Historical USers cohort (OrPHeUS) medical chart review provide real‐world data for patients newly initiating macitentan. This study aims to describe the characteristics, safety profile, and clinical outcomes of PAH patients newly treated with macitentan in the combined OPUS/OrPHeUS data set. OPUS was a prospective, multicenter, long‐term, observational drug registry from April 2014 to June 2020. OrPHeUS was a retrospective, US, multicenter chart review: observation period October 2013 to March 2017. All analyses were descriptive. At registry closure in June 2020, the combined population consisted of 5654 patients, of whom 81.9% were diagnosed with PAH. For these 4626 patients, median duration of macitentan exposure observed was 14.5 (Q1 = 5.2, Q3 = 29.0) months; idiopathic PAH (54.8%) was the most common form of PAH; macitentan was initiated as monotherapy (37.9%), or as part of double (48.0%) or triple therapy (14.1%); discontinuation due to nonhepatic/hepatic adverse events occurred in 17.1%/0.3% of patients; 9.9% of patients experienced ≥1 hepatic adverse events; Kaplan–Meier estimates showed that at 1 year 59.9% (95% confidence interval: 58.3, 61.5) of patients were free from hospitalization and survival was 90.4% (89.3, 91.3). This analysis of real‐world data from the combined OPUS and OrPHeUS populations demonstrated that macitentan is well tolerated in a large, diverse population of PAH patients, with overall and hepatic safety profiles consistent with previous macitentan clinical trials.

Interspecies differences in clinical characteristics and risk factors for third-generation cephalosporin resistance between Escherichia coli and Klebsiella pneumoniae bloodstream infection in patients with liver cirrhosis

This retrospective study aimed to clarify the interspecies differences in the clinical characteristics and risk factors of bloodstream infection (BSI) due to third-generation cephalosporin-resistant (3GC-R) Escherichia coli (EC) and Klebsiella pneumoniae (KP) in patients with liver cirrhosis (LC). KP BSI had more comorbidities and higher treatment failure rate than EC BSI. Non-alcoholic LC was a risk factor for treatment failure in EC, whereas it was not associated with KP. Risk factors for BSI due to 3GC-R strain were nosocomial infection in EC, and β-lactam/fluoroquinolone treatment ≤ 30 days in KP. These results could help predict outcomes of BSI and improve clinical practice.

Concomitant initiation of combination therapy with macitentan and tadalafil in pulmonary arterial hypertension (PAH) patients with comorbidities: real-world data from OPUS and OrPHeUS

Background

Guidelines for the management of pulmonary arterial hypertension (PAH) recommend early combination therapy of an endothelial receptor antagonist (ERA) and a phosphodiesterase type-5 inhibitor (PDE5i) [1]. There is, however, limited guidance about the management of PAH patients with comorbidities.

Purpose

To describe the demographics, clinical characteristics, safety, tolerability, and outcomes associated with initiation of the ERA macitentan and the PDE5i tadalafil in patients with comorbidities in the US OPsumit® USers (OPUS) and the OPsumit® Historical USers cohort (OrPHeUS) combined dataset.

Methods

This analysis reports data from the OPUS registry (Apr 2014–Jun 2020) and OrPHeUS medical chart review (Oct 2013–Mar 2017) on PAH patients initiating macitentan and tadalafil (M+T) combination therapy, in any order, as concomitant initiation (≤60 days apart, concomitant initiation group). The index date was defined as the start date of the second therapy (i.e., the start of combination therapy). Patients were further grouped by the number of comorbidities present prior to or at macitentan initiation: systemic hypertension, diabetes, renal insufficiency, BMI ≥30 kg/m2, other signs of right heart failure and atrial fibrillation. Results are presented descriptively alongside results for all PAH patients receiving M+T combination therapy (overall M+T group).

Results

Of the 1336 PAH patients that received M+T combination therapy, 431 (32%) were in the concomitant initiation group. In the concomitant initiation and overall M+T groups, respectively: 72% and 68% had ≥1 comorbidity, and the most common were systemic hypertension (47% and 47%), obesity (32% and 26%) and diabetes (23% and 22%). Patients were more likely to be older, male and have idiopathic/heritable PAH with increasing comorbidity burden (Table 1). Patients in the concomitant initiation group were more likely to be incident (median time from diagnosis: 1–2 months vs 9–24 months in the overall M+T group; Table 1). Most patients had ≥1 adverse event (AE); in both groups, patients with a high comorbidity burden (≥3) were more likely to have had an AE and to have discontinued treatment (Table 2). The incidence rate of first all-cause hospitalisation and mortality by comorbidity was comparable between the concomitant initiation and overall M+T groups.

Conclusions

In the real-world, concomitant initiation of M+T is used in PAH patients with comorbidities, usually shortly after diagnosis. Patient characteristics were similar for the concomitant initiation and overall M+T groups, with the exception of time from diagnosis. At index date, age, gender proportion, and PAH aetiology differed between the comorbidity groups. The safety profile of M+T combination therapy in the concomitant initiation group was consistent with that in the overall M+T group.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Actelion Pharmaceuticals Ltd, a Janssen Pharmaceutical Company of Johnson & Johnson

Effect of the Concomitant Use of Subcutaneous Basal Insulin and Intravenous Insulin Infusion in the Treatment of Severe Hyperglycemic Patients

BACKGRUOUND

No consensus exists regarding the early use of subcutaneous (SC) basal insulin facilitating the transition from continuous intravenous insulin infusion (CIII) to multiple SC insulin injections in patients with severe hyperglycemia other than diabetic ketoacidosis. This study evaluated the effect of early co-administration of SC basal insulin with CIII on glucose control in patients with severe hyperglycemia.

METHODS

Patients who received CIII for the management of severe hyperglycemia were divided into two groups: the early basal insulin group (n=86) if they received the first SC basal insulin 0.25 U/kg body weight within 24 hours of CIII initiation and ≥4 hours before discontinuation, and the delayed basal insulin group (n=79) if they were not classified as the early basal insulin group. Rebound hyperglycemia was defined as blood glucose level of >250 mg/dL in 24 hours following CIII discontinuation. Propensity score matching (PSM) methods were additionally employed for adjusting the confounding factors (n=108).

RESULTS

The rebound hyperglycemia incidence was significantly lower in the early basal insulin group than in the delayed basal insulin group (54.7% vs. 86.1%), despite using PSM methods (51.9%, 85.2%). The length of hospital stay was shorter in the early basal insulin group than in the delayed basal insulin group (8.5 days vs. 9.6 days, P=0.027). The hypoglycemia incidence did not differ between the groups.

CONCLUSION

Early co-administration of basal insulin with CIII prevents rebound hyperglycemia and shorten hospital stay without increasing the hypoglycemic events in patients with severe hyperglycemia.

Association Between Higher Variability in Kidney Function and Long-term Mortality

AIM

We evaluated whether estimated glomerular filtration rate variability in the general population could be associated with all-cause mortality.

METHODS

Health examination data from 7,842 individuals aged >20 years who visited for health check-ups at least thrice at ≥6-month intervals between May 1, 1995 and November 30, 2010 were collected. Estimated glomerular filtration rate variability was defined as the coefficient of variation of the estimated glomerular filtration rate, i.e., standard deviation/mean value multiplied by 100. The study population was divided into three groups based on the coefficient of variation tertiles, and the mortality risks were compared across groups.

RESULTS

The mean duration from the final visit to the outcome was 10.3±2.9 years. The mean coefficient of variations of estimated glomerular filtration rate variability from the lowest to the highest variability group were 5.1±1.8%, 9.0±1.0%, and 14.4±3.9%, respectively. There was a 1.3 times higher risk of mortality in the group with the highest variability (hazard ratio: 1.300, 95% confidence interval: 1.013-1.669) after adjustment. The findings were similar in patients with diabetes and those >60 years old (hazard ratio: 1.635, 95% confidence interval: 1.076-2.483; hazard ratio: 1.585, 95% confidence interval: 1.107-2.269).

CONCLUSION

Higher estimated glomerular filtration rate variability was associated with increased 10-year mortality in the general population. This variability was very small, but considering the patients' long-term prognoses, it was significant. This article is protected by copyright. All rights reserved.

31. Stepwise Expansion of Antimicrobial Stewardship Program and Its Impact on Antibiotic Use and Resistance Rates in a Tertiary Care Hospital in Korea

Background

The U.S. Centers for Disease Control and Prevention released the core elements of antimicrobial stewardship program (ASP). In some countries, however, they may be difficult to apply in countries with limited resources. In this study, we evaluated the impact of successful ASP implementation on antibiotic use and resistance rates in an institution with limited infrastructural support.

Methods

A series of ASP activities were reviewed according to the core elements of ASP. The retrospective data of all hospitalized patients at a tertiary care teaching hospital was collected from January 2010 to December 2019, including antibiotic prescription data and culture results of all clinical specimens. The trends of the antibiotic-resistant rates were compared with nationwide data in Korea. The trend analyses were performed with 2-sided correlated seasonal Mann-Kendall nonparametric tests.

Results

The ASP activities over the past decade were summarized in Table. After activities such as preauthorization were achieved, other ASP activities were added one by one. Also, the infectious disease pharmacists, as ASP co-leaders, mainly carried out the following activities: reducing redundant anti-anaerobic antimicrobials and intravenous fluoroquinolones, and advised the physicians to discontinue the antibiotic prescription in cases when the intervention was plausible. After the ASP implementation, total antibacterial use significantly decreased (P &lt; 0.01; Figure). The use of glycopeptides (P &lt; 0.01) and fluoroquinolones (P &lt; 0.01) gradually decreased, while the use of third-generation cephalosporines did not significantly change (P=0.48). There was no significant change in total carbapenems use, but ertapenem use increased (P=0.02). Compared with the nationwide data, methicillin-resistant Staphylococcus aureus was on a decreasing trend consistently. Although third-generation cephalosporin-resistant Escherichia coli increased, third-generation cephalosporin resistant-Klebsiella pneumoniae and carbapenem resistant-Pseudomonas aeruginosa did not increase.

Table. Antimicrobial stewardship activities for hospitalized patients over the past decade in Seoul National University Bundang Hospital. ASP: antimicrobial stewardship; ID: infectious disease; CDSS: Clinical decision support system

Conclusion

A stepwise implementation of the core ASP elements was effective in improving the appropriate use of antibiotics and reducing the antibiotic resistant organisms, even with limited human resources.

Disclosures

All Authors: No reported disclosures

Role of bicarbonate and volume therapy in the prevention of acute kidney injury in rhabdomyolysis: a retrospective propensity score-matched cohort study

Background

Although bicarbonate has traditionally been used to treat patients with rhabdomyolysis at high risk of acute kidney injury (AKI), it is unclear whether this is beneficial. This study compared bicarbonate therapy to non-bicarbonate therapy for the prevention of AKI and mortality in rhabdomyolysis patients.

Methods

In a propensity score-matched cohort study, patients with a creatine kinase (CK) level of >1,000 U/L during hospitalization were divided into bicarbonate and non-bicarbonate groups. Patients were subgrouped based on low-volume (<3 mL/kg/hr) or high-volume (≥3 mL/kg/hr) fluid resuscitation in the first 72 hours. Logistic regression analyses were used to identify the impacts of bicarbonate use and fluid resuscitation on AKI risk and need for dialysis. The Kaplan-Meier method was used to estimate survival. Volume overload and electrolyte imbalances were assessed.

Results

Among 4,077 patients, we assembled a cohort of 887 pairs of patients treated with and without bicarbonate. Bicarbonate group had a higher incidence of AKI, higher rate of dialysis dependency, higher 30-day mortality, and longer hospital stay than the non-bicarbonate group. Further, patients who received high-volume fluid therapy had worse renal outcomes and a higher mortality than those who received low-volume fluids regardless of bicarbonate use. Bicarbonate use, volume overload, and AKI were associated with higher mortality. Volume overload was significantly higher in the bicarbonate group than in the non-bicarbonate group.

Conclusion

Bicarbonate or high-volume fluid therapy for patients with rhabdomyolysis did not reduce AKI or improve mortality compared to non-bicarbonate or low-volume fluid therapy. Limited use of bicarbonate and adjustment of fluid volume may improve the short- and long-term outcomes of patients with rhabdomyolysis.

A Smart Diaper System Using Bluetooth and Smartphones to Automatically Detect Urination and Volume of Voiding: Prospective Observational Pilot Study in an Acute Care Hospital

Background

Caregivers of patients who wear conventional diapers are required to check for voiding every hour because prolonged wearing of wet diapers causes health problems including diaper dermatitis and urinary tract infections. However, frequent checking is labor intensive and disturbs patients’ and caregivers’ sleep. Furthermore, assessing patients’ urine output with diapers in an acute care setting is difficult. Recently, a smart diaper system with wetness detection technology was developed to solve these issues.

Objective

We aimed to evaluate the applicability of the smart diaper system for urinary detection, its accuracy in measuring voiding volume, and its effect on incontinence-associated dermatitis (IAD) occurrence in an acute care hospital.

Methods

This prospective, observational, single-arm pilot study was conducted at a single tertiary hospital. We recruited 35 participants aged ≥50 years who were wearing diapers due to incontinence between August and November 2020. When the smart diaper becomes wet, the smart diaper system notifies the caregiver to change the diaper and measures voiding volume automatically. Caregivers were instructed to record the weight of wet diapers on frequency volume charts (FVCs). We determined the voiding detection rate of the smart diaper system and compared the urine volume as automatically calculated by the smart diaper system with the volume recorded on FVCs. Agreement between the two measurements was estimated using a Bland-Altman plot. We also checked for the occurrence or aggravation of IAD and bed sores.

Results

A total of 30 participants completed the protocol and 390 episodes of urination were recorded. There were 108 records (27.7%) on both the FVCs and the smart diaper system, 258 (66.2%) on the FVCs alone, 18 (4.6%) on the smart diaper system alone, and 6 (1.5%) on the FVCs with sensing device lost. The detection rate of the smart diaper system was 32.8% (126/384). When analyzing records concurrently listed in both the FVCs and the smart diaper system, linear regression showed a strong correlation between the two measurements (R²=0.88, P<.001). The Bland-Altman assessment showed good agreement between the two measurements, with a mean difference of –4.2 mL and 95% limits of agreement of –96.7 mL and 88.3 mL. New occurrence and aggravation of IAD and bed sores were not observed. Bed sores improved in one participant.

Conclusions

The smart diaper system showed acceptable accuracy for measuring urine volume and it could replace conventional FVCs in acute setting hospitals. Furthermore, the smart diaper system has the potential advantage of preventing IAD development and bed sore worsening. However, the detection rate of the smart diaper system was lower than expected. Detection rate polarization among participants was observed, and improvements in the user interface and convenience are needed for older individuals who are unfamiliar with the smart diaper system.

Clinical and economic impact of medication reconciliation by designated ward pharmacists in a hospitalist-managed acute medical unit

BACKGROUND

Minimizing unintended medication errors after admission is a common goal for clinical pharmacists and hospitalists.

OBJECTIVE

We assessed the clinical and economic impact of a medication reconciliation service in a model of designated ward pharmacists working in a hospitalist-managed acute medical unit as part of a multidisciplinary team.

METHODS

In this retrospective observational study, we compared pharmacist intervention records before and after the implementation of a medication reconciliation service by designated pharmacists. The frequency and type of intervention were assessed and their clinical impact was estimated according to the length of hospital stay and 30-day readmission rate. A cost analysis was performed using the average hourly salary of a pharmacist, cost of interventions (time spent on interventions), and cost avoidance (avoided costs generated by interventions).

RESULTS

After the implementation of the medication reconciliation service, the frequency of pharmacist interventions increased from 3.9% to 22.1% (p < 0.001). Intervention types were also more diverse than those before the implementation. The most common interventions included identifying medication discrepancies between pre-admission and hospitalization (22.7%) and potentially inappropriate medication use in the elderly (13.1%). The median length of hospital stay decreased from 9.6 to 8.9 days (p = 0.024); the 30-day readmission rate declined significantly from 7.8% to 4.8% (p = 0.046). Over two-thirds of interventions accepted by hospitalists were considered clinically significant or greater in severity. The cost difference between avoided cost and cost of interventions was 9838.58 USD in total or 1967.72 USD per month.

CONCLUSIONS

The implementation of a designated pharmacist-led medication reconciliation service had a positive clinical and economic impact in our hospitalist unit.

1605. Differences in Clinical Characteristics of Third Generation Cephalosporin Resistance and Treatment Outcomes in Escherichia coli and Klebsiella pneumoniae Bacteremia in Patients with Liver Cirrhosis

Background

This study aimed to identify characteristics of third-generation cephalosporin (3GC) resistance in Escherichia coli bateremia (ECB) and Klebsiella pneumoniae bacteremia (KPB) in patients with liver cirrhosis (LC), and to investigate the effects of appropriateness of empirical antibiotic treatment on outcomes.

Methods

We retrospectively collected demographic, clinical and microbiological information on all ECB and KPB episodes in LC patients ≥ 18 years of age hospitalized to a tertiary-care teaching hospital in South Korea from 2007 to 2018. Clinical characteristics associated with 3GC resistance and treatment failure were analyzed using a multivariate logistic regression model. Treatment failure was defined as persistent bacteremia for ≥ 7 days, or relapsed bacteremia ≤ 30 days, or all-cause mortality ≤ 30 days.

Results

3GC resistance rates of E. coli were 30.3% overall and increased significantly during the study period (P=0.001), while the rates of K. pneumoniae were not changed (24.3% overall) (P=0.994). Of total 356 ECB and KPB episodes, 112 were caused by 3GC resistant strains. The factor associated with 3GC resistance was isolation of 3GC resistant strain ≤ 1 year in both ECB (OR, 7.754; 95% CI, 2.094~28.716) and KPB (OR, 2.774; 1.318~5.838). In ECB, beta-lactam or fluoroquinolone treatment ≤ 30 days was another factor associated with 3GC resistance (OR, 2.774; 95% CI, 1.318~5.838), but not in KPB. The factor associated with treatment failure was high MELD score in both ECB (OR, 1.193 at 1 increase; 95% CI, 1.118~1.272) and KPB (OR, 1.163; 95% CI 1.083~1.250). Additionally, in ECB, non-alcoholic LC (OR 3.262; 95% CI 1.058~10.063), high Charlson Comorbidity Index (OR, 1.285; 95% CI 1.066~1.548), and inappropriate empirical antibiotic treatment (OR, 3.194; 95% CI 1.207~8.447) were associated with treatment failure.

Conclusion

During the study period, 3GC resistance increased in ECB, but not in KPB. In ECB, the severity of the underlying disease and the appropriateness of empirical antibiotics were associated with treatment failure, but there was no correlation in KPB. In ECB of LC patients, the appropriateness of empirical antibiotics was a factor associated with treatment outcome, and is the only correctable factor in the clinical setting.

Disclosures

All Authors: No reported disclosures

Toll-like receptor 2 downregulation and cytokine dysregulation predict mortality in patients with Staphylococcus aureus bacteremia

BACKGROUND

Staphylococcus aureus bacteremia (SAB) presents heterogeneously, owing to the differences in underlying host conditions and immune responses. Although Toll-like receptor 2 (TLR2) is important in recognizing S. aureus, its function during S. aureus infection remains controversial. We aimed to examine the association of TLR2 expression and associated cytokine responses with clinical SAB outcomes.

METHODS

Patients from a prospective SAB cohort at two tertiary-care medical centers were enrolled. Blood was sampled at several timepoints (≤5 d, 6-9 d, 10-13 d, 14-19 d, and ≥ 20 d) after SAB onset. TLR2 mRNA levels were determined via real-time PCR and serum tumor necrosis factor [TNF]-α, interleukin [IL]-6, and IL-10 levels were analyzed with multiplex-high-sensitivity electrochemiluminescent ELISA.

RESULTS

TLR2 levels varied among 59 SAB patients. On days 2-5, TLR2 levels were significantly higher in SAB survivors than in healthy controls (p = 0.040) and slightly but not significantly higher than non-survivors (p = 0.120), and SAB patients dying within 7 d had lower TLR2 levels than survivors (P = 0.077) although statistically insignificant. IL-6 and IL-10 levels were significantly higher in non-survivors than in survivors on days 2-5 post-bacteremia (P = 0.010 and P = 0.021, respectively), and those dying within 7 d of SAB (n = 3) displayed significantly higher IL-10/TNF-α ratios than the survivors did (P = 0.007).

CONCLUSION

TLR2 downregulation and IL-6 and IL-10 concentrations suggestive of immune dysregulation during early bacteremia may be associated with mortality from SAB. TLR2 expression levels and associated cytokine reactions during early-phase SAB may be potential prognostic factors in SAB, although larger studies are warranted.

Predictive scoring models for persistent gram-negative bacteremia that reduce the need for follow-up blood cultures: a retrospective observational cohort study

Background

Although the risk factors for positive follow-up blood cultures (FUBCs) in gram-negative bacteremia (GNB) have not been investigated extensively, FUBC has been routinely carried out in many acute care hospitals. We attempted to identify the risk factors and develop a predictive scoring model for positive FUBC in GNB cases.

Methods

All adults with GNB in a tertiary care hospital were retrospectively identified during a 2-year period, and GNB cases were assigned to eradicable and non-eradicable groups based on whether removal of the source of infection was possible. We performed multivariate logistic analyses to identify risk factors for positive FUBC and built predictive scoring models accordingly.

Results

Out of 1473 GNB cases, FUBCs were carried out in 1268 cases, and the results were positive in 122 cases. In case of eradicable source of infection, we assigned points according to the coefficients from the multivariate logistic regression analysis: Extended spectrum beta-lactamase-producing microorganism (+ 1 point), catheter-related bloodstream infection (+ 1), unfavorable treatment response (+ 1), quick sequential organ failure assessment score of 2 points or more (+ 1), administration of effective antibiotics (− 1), and adequate source control (− 2). In case of non-eradicable source of infection, the assigned points were end-stage renal disease on hemodialysis (+ 1), unfavorable treatment response (+ 1), and the administration of effective antibiotics (− 2). The areas under the curves were 0.861 (95% confidence interval [95CI] 0.806–0.916) and 0.792 (95CI, 0.724–0.861), respectively. When we applied a cut-off of 0, the specificities and negative predictive values (NPVs) in the eradicable and non-eradicable sources of infection groups were 95.6/92.6% and 95.5/95.0%, respectively.

Conclusions

FUBC is commonly carried out in GNB cases, but the rate of positive results is less than 10%. In our simple predictive scoring model, zero scores—which were easily achieved following the administration of effective antibiotics and/or adequate source control in both groups—had high NPVs. We expect that the model reported herein will reduce the necessity for FUBCs in GNB cases.

Impact of a delirium prevention project among older hospitalized patients who underwent orthopedic surgery: a retrospective cohort study

Background

Postoperative delirium (POD) is a common clinical syndrome with significant negative outcomes. Thus, we aimed to evaluate the feasibility and effectiveness of a delirium screening tool and multidisciplinary delirium prevention project.

Methods

A retrospective cohort study was conducted at a single teaching center in Korea. A cohort of patients who underwent a delirium prevention program using a simple delirium screening tool from December 2018 to February 2019 (intervention group, N = 275) was compared with the cohort from the year before implementation of the delirium prevention program (December 2017 to February 2018) (control group, N = 274). Patients aged ≥65 years who were admitted to orthopedic wards and underwent surgery were included. The incidence rates of delirium before and after implementation of the delirium prevention program, effectiveness of the delirium screening tool, change in the knowledge score of nurses, and length of hospital stay were assessed.

Results

The sensitivity and specificity of the screening tool for the incidence of POD were 94.1 and 72.7%, respectively. The incidence rates of POD were 10.2% (control group) and 6.2% (intervention group). The odds ratio for the risk reduction effect of the project related to the incidence of POD was 0.316 (95% confidence interval: 0.125–0.800, p = 0.015) after adjustment for possible confounders. The delirium knowledge test score increased from 40.52 to 43.24 out of 49 total points (p < 0.001). The median length of hospital stay in the intervention and control groups was 6.0 (interquartile range, 4–9) and 7.0 (interquartile range, 4–10) days, respectively (p = 0.062).

Conclusion

The screening tool successfully identified patients at a high risk of POD at admission. The POD prevention project was feasible to implement, effective in preventing delirium, and improved knowledge regarding delirium among the medical staff.

Trial registration

None.

P3671Selexipag dosing and titration in the first 500 patients enrolled in SPHERE (SelexiPag: tHe UsErs dRug rEgistry)

Introduction

SPHERE is an ongoing US-based, multicentre, prospective, registry collecting data on use of the oral selective IP prostacyclin receptor agonist selexipag in real-world settings. Here, we report selexipag dosing and titration in the first 500 patients.

Methods

SPHERE, initiated in November 2016, will enrol 800 patients newly initiated on or already treated with selexipag at enrolment who have a documented titration regimen. Patients are followed for up to 18 months. Patients were considered “newly initiated” on selexipag if they were enrolled in SPHERE ≤60 days after starting selexipag and were considered “previously initiated” if they enrolled >60 days after starting selexipag. The highest dose is the maximum dose reached during up-titration within 6 months since initiation. Selexipag “maintenance dose” is defined as the first dose received for ≥14 days without interruption or change; “titration speed” is defined as the highest dose reached within the first 6 months after initiation divided by the time (in weeks) to reach it.

Results

The data cut-off for this analysis was December 20, 2018. Most patients had Group 1 pulmonary hypertension (PH) (95.4%), which was primarily idiopathic (49.6%) or connective tissue disease associated (26.0%). At selexipag initiation 49.8% of patients had functional class III symptoms. At the time of selexipag initiation, 19.2% of patients were on PH therapy containing a prostacyclin pathway agent (PPA) (8.5% with a parenteral PPA). The median maintenance dose of selexipag was 1200 μg BID (IQR: 800–1600 μg BID) and the median time to reach it was 8.1 wks (IQR: 5.3–11.0 wks). Low (≤400 μg BID), medium (600–1000 μg BID), and high (≥1200 μg BID) maintenance doses were attained by 15.1%, 30.8%, and 49.5% of patients, respectively (and in 23.2%, 31.2%, and 36.2%, respectively, in GRIPHON). The median titration speed was 175 μg BID/wk (IQR: 110.5–195.3 μg BID/wk), slower than the protocol-outlined 200 μg BID/wk in GRIPHON. In SPHERE, most patients titrated at speeds <200 μg BID/wk, regardless of whether they were newly (175 μg BID/wk; IQR 118.6, 195.3) or previously (175 μg BID/wk; IQR 109.8, 195.3) initiated. As expected, more patients discontinued due to adverse events in the newly (29.0%) versus previously (14.1%) initiated groups. The most common adverse events leading to selexipag discontinuation were worsening pulmonary hypertension (2.2%), headache (2.0%), myalgia (1.4%), and nausea (1.0%).

Conclusion

The median maintenance selexipag dose in SPHERE was 1200 μg BID. While the median titration speed was 175 μg BID/wk, there was marked variation and the vast majority of patients titrated slower than 200 μg BID/wk. No new safety signals were observed.

Acknowledgement/Funding

Actelion Pharmaceuticals US, Inc.

P2540Sex-specific differences in the clinical presentation, surgical complications, and course of chronic thromboembolic pulmonary hypertension

Background

Women are more susceptible to develop several forms of pulmonary hypertension, but they may have better survival rates than men. Sparse data are available concerning sex-specific differences in chronic thromboembolic pulmonary hypertension (CTEPH).

Purpose and methods

We investigated sex-specific differences in the clinical presentation of CTEPH, functional parameters, exposure to pulmonary endarterectomy (PEA), and survival.

Results

Women constituted half of the study population (N=679 treatment-naïve patients from the European CTEPH registry) and were characterized by a lower prevalence of some cardiovascular risk factors (e.g. prior acute coronary syndrome, smoking habit, chronic obstructive pulmonary disease), but more prevalent obesity, cancer, and thyroid diseases. Median age was 62 (IQR 50–73) years in women and 63 (IQR 53–70) in men. Women underwent PEA less often than men (54% vs 65%; Figure 1, Panel A) and were exposed to fewer additional cardiac procedures, notably coronary artery bypass graft surgery (0.5% vs. 9.5%). The prevalence of specific reasons for not being operated, including the patient's refusal and the proportion of proximal vs. distal lesions, did not differ between sexes. A total of 57 (17.0%) deaths in women and 70 (20.7%) in men were recorded over long-term follow-up. Female sex was positively associated with long-term survival (adjusted Hazard Ratio 0.66; 95% Confidence Interval 0.46–0.94). Short-term mortality was identical in the two groups (Figure 1, Panel B).

Conclusions

Women with CTEPH had a lower prevalence of cardiovascular risk factors and underwent PEA less frequently than men, who, in turn, were more often exposed to additional major cardiac surgery procedures. Women had more favorable long-term survival.

Acknowledgement/Funding

The CTEPH registry is supported by a research grant from Actelion Pharmaceuticals Ltd.

Immunogenicity and safety of a novel recombinant protective antigen anthrax vaccine (GC1109), a randomized, single-blind, placebo controlled phase II clinical study

BACKGROUND

The demand on effective and safe anthrax vaccine is increasing as a part of the preparedness for possible bioterrorism in the future. We performed a randomized, single-blind, placebo controlled phase II clinical study to evaluate the immunogenicity and safety of a novel recombinant protective antigen (rPA) anthrax vaccine, GC1109, in healthy adult volunteers.

METHODS

Participants were randomized to experiment groups (0.3 mL, 0.5 mL, and 1.0 mL of GC1109) or placebo group (normal saline 0.5 mL) in 2:2:2:1 ratio. They received respective vaccines intramuscularly at 0, 4 and 8 weeks. Immunogenicity was evaluated by seroconversion rate and geometric mean titer (GMT) of lethal toxin neutralizing assay (TNA) and anti-PA IgG by ELISA. Safety was assessed by laboratory tests, and solicited and unsolicited adverse events on diary cards.

RESULTS

30, 29, 30 participants were randomized to 0.3, 0.5, and 1.0 mL of GC1109 groups, respectively, while 15 to placebo group. 92 participants received all three doses. In per-protocol analysis, TNA GMTs at week 12 were 296.5, 285.2, and 433.2 in the three groups, respectively. Seroconversion rates measured by ELISA were 100% at week 12 in the three groups. Local and systemic vaccine-related adverse events were frequent; however, most of them were mild, and no serious events were observed.

CONCLUSIONS

A new rPA anthrax vaccine GC1109 was immunogenic after three doses of intramuscular administration, and was well-tolerated.

Abstract P1-08-21: Association of depression and anxiety disorder with the risk of mortality in breast cancer: A national health insurance service study in South Korea

PURPOSE: To examine whether depression, anxiety disorder and their co-occurrence would increase the risk of mortality in patients with breast cancer, and whether antidepressant treatment would reduce the same.

PATIENTS AND METHODS: Data were retrieved from the database of the Korean National Health Insurance Service. Of 145,251 patients diagnosed with breast cancer between 2007 and 2014, 20,870 patients diagnosed with depression or anxiety disorder one year before breast cancer diagnosis were excluded. Thus, data of 124,381 patients were included in this study.

RESULTS: Anxiety disorder was more prevalent than depression in patients with breast cancer, and similar factors were associated with both depression and anxiety disorder. Overall, female sex, older age, residence in metropolitan areas, lower income, higher comorbidity, carcinoma in situ, and the receipt of any type of cancer therapies were associated with an increased risk of depression or anxiety disorder. Depression and anxiety disorder were associated with an increased risk of mortality (Hazard Ratio (HR) = 1.26, 95% CI=1.18–1.36; HR=1.14, 95% CI=1.08–1.22, respectively) and their co-occurrence further increased the risk (HR=1.38, 95% CI=1.24–1.54). Antidepressant treatment was related to a reduced risk of mortality. Compared to patients with no depression, among those with depression, the risk of mortality was 2.18 times higher (95% CI=1.69–2.81) in patients who did not receive antidepressant treatment and 1.25 times higher (95% CI =1.17–1.32) in those who received antidepressant treatment.

CONCLUSION: The current findings suggest that psychiatric comorbidities are markers of increased mortality risk in patients with breast cancer. This underscores the need for screening and treating depression and anxiety disorders to improve survival in breast cancer.

Citation Format: Kim YS, Shim E-J, Lee JW, Cho J, Jung HK, Kim NH, Lee JE, Min J, Noh WC, Park S-H. Association of depression and anxiety disorder with the risk of mortality in breast cancer: A national health insurance service study in South Korea [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-08-21.

Factors Affecting Microbiological Quality of Vegetable- and Meat-Based Meals Served at Cafeterias in the Republic of Korea

A total of 364 samples of vegetable- and meat-based meals were collected at three processing steps: step I, preparation of raw ingredients; step II, processing and cooking; and step III, finished meals. Microbiological quality was evaluated by using data for the prevalence and concentration of the aerobic plate counts, total coliforms (TC), fecal coliforms (FC), and Escherichia coli. The data were analyzed for differences between cafeterias, seasons, raw materials, and processing steps. Fourteen (15.2%) of the 92 finished meal samples were microbiologically unsatisfactory. Neither cafeteria nor season was significantly associated with microbiological quality ( P > 0.05). However, the type of raw ingredients and processing steps were significantly associated with differences in microbiological quality. Vegetable-based meals had higher TC concentrations than meat-based meals because salad and seasoned and fermented vegetables are not cooked, unlike heat-processed meat products. Microbial counts tended to decrease through the processing steps, and E. coli, which could only be enumerated on uncooked chicken breast (1.6 log CFU/g) and sliced pork (2.6 log CFU/g), was totally eliminated by boiling and roasting. However, the presence of FC was not completely eliminated, even by cooking, and so this group of organisms should be considered as an important indicator of hygienic meal preparation in cafeterias. Although pathogenic E. coli was not isolated in this study, continuous microbiological monitoring of composite foods served in cafeterias should be performed as the presence of TC and FC in finished meals indicates the potential for contamination by pathogenic E. coli.

Dipeptidyl peptidase-4 inhibitor use and risk of diabetic retinopathy: A population-based study

AIMS

This study examined whether dipeptidyl peptidase (DPP)-4 inhibitor use is beneficial or harmful to diabetic retinopathy (DR) compared with other glucose-lowering agents in patients with type 2 diabetes (T2D).

METHODS

From a population-based cohort provided by the National Health Insurance Service in Korea, 67,743 adults with T2D were identified as having been treated with oral glucose-lowering agents between 2008 and 2013. Matching (1:1) was performed for two groups comparing ever-use (cases) and never-use (controls) of DPP-4 inhibitors (n=14,522 in each group). Cox regression analyses were used to assess risk of the following DR events: vitreous haemorrhage; vitrectomy or photocoagulation; intravitreal agent use; and blindness.

RESULTS

During a median follow-up of 28.4 (14.0-45.2) months, there were 305 (in controls) and 342 (in cases) composite DR events. DPP-4 inhibitor ever-use was not associated with overall risk of composite DR events [adjusted hazard ratio (HR): 1.08, 95% CI: 0.93-1.26] compared with never-use, nor was the risk of each DR outcome increased with DPP-4 inhibitor therapy either. However, DPP-4 inhibitor administration for<12 months was associated with a greater risk of composite DR events (adjusted HR: 1.31, 95% CI: 1.09-1.57) compared with other glucose-lowering agents over the same treatment period.

CONCLUSION

In comparison to other oral glucose-lowering agents, DPP-4 inhibitor treatment did not increase overall risk of DR. However, DPP-4 inhibitors may be associated with an increased risk of retinopathy events early in the treatment phase.

A Risk-Scoring System for Predicting Methicillin Resistance in Community-Onset Staphylococcus aureus Bacteremia in Korea

AIMS

We aimed to develop a simple scoring system to predict risk for methicillin resistance in community-onset Staphylococcus aureus bacteremia (CO-SAB) by identifying the clinical and epidemiological risk factors for community-onset methicillin-resistant S. aureus (MRSA).

METHODS

We retrospectively analyzed data from three multicenter cohort studies in Korea in which patient information was prospectively collected and risk factors for methicillin resistance in CO-SAB were identified. We then developed and validated a risk-scoring system.

RESULTS

To analyze the 1,802 cases of CO-SAB, we included the four most powerful predictors of methicillin resistance that we identified in the scoring system: underlying hematologic disease (-1 point), endovascular infection as the primary site of infection (-1 point), history of hospitalization or surgery in ≤1 year (+0.5 points), and previous isolation of MRSA in ≤6 months (+1.5 points). With this scoring system, cases were classified into low (less than -0.5), intermediate (-0.5-1.5), and high (≥1.5) risk groups. The proportions of MRSA cases in each group were 24.7% (22/89), 39.0% (607/1,557), and 78.8% (123/156), respectively, and 16.7% (1/6), 33.8% (112/331), and 76.9% (10/13) in a validation set.

CONCLUSIONS

This risk-scoring system for methicillin resistance in CO-SAB may help physicians select appropriate empirical antibiotics more quickly.

Complete mitochondrial genome of the Amur hedgehog Erinaceus amurensis (Erinaceidae) and higher phylogeny of the family Erinaceidae

We sequenced and characterized the complete mitogenome (KX964606) of the Amur hedgehog Erinaceus amurensis to provide more data for comparative mitogenomics of the genus Erinaceus (Erinaceidae). The mitogenome of E. amurensis is a circular molecule 16,941 bp long, consisting of a control region and a conserved set of 37 genes containing 13 protein-coding genes, 22 tRNA genes, and two rRNA genes (12S rRNA and 16S rRNA). The mitogenome of E. amurensis is AT-biased, with a nucleotide composition of 33.9% A, 21.1% C, 32.6% T, and 12.4% G. The mitogenomes of E. amurensis and the closely related hedgehog species E. europaeus, excluding the control region (66.7%), share over 90% sequence similarity. According to the inter-generic relationship based on six mitogenomes described from five genera of Erinaceidae, the subfamilies Erinaceinae and Galericinae are strongly supported as monophyletic groups, with each genus well placed within its own subfamily. Within the subfamily Erinaceinae, E. amurensis is a sister species to E. europaeus, and the relationship between Hemiechinus and Erinaceus is strongly supported. Within the subfamily Galericinae, the clade of Hylomys + Neotetracus was sister to that of Echinosorex, with clades supported by high values. Our findings will help to understand the codon usage pattern and molecular evolution of E. amurensis, and provide insight into inter-generic relationships within the family Erinaceidae. In future studies, the inclusion of mitogenomes from other genera would greatly enhance our understanding of higher phylogeny within the Erinaceidae.

Destruction of Bacillus cereus spores in a thick soy bean paste (doenjang) by continuous ohmic heating with five sequential electrodes

This study selected spores from Bacillus cereus FSP-2 strain (the isolate from a commercial doenjang processing line) as the test strain which showed significantly higher thermal resistance (P < 0·05) than B. cereus reference strain (ATCC 27348). The spores in doenjang were subjected to ohmic heating (OH) at 95, 105, 115 and 125°C for 30, 60 or 90 s using a five sequential electrode system (electrical field: 26·7 V cm(-1) ; alternating current frequency: 25 kHz). OH at 105°C for 30-90 s reduced the B. cereus spore count in doenjang samples to <4 log CFU g(-1) . Since OH treatment at 115 and 125°C caused a perceivable colour change in the product (>1·5 National Bureau of Standards units), treatment at 105°C for 60 s was selected and applied on a large scale (500 kg of product). Reliable and reproducible destruction of B. cereus spores occurred; the reductions achieved (to < 4 log CFU g(-1) ) met the Korean national standards. Scanning electron microscopy revealed microstructural alterations in the spores (shrinkage and a distorted outer spore coat). OH is an effective method for destroying B. cereus spores to ensure the microbiological quality and safety of a thick, highly viscous sauce.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study shows that an ohmic heating (OH) using a five sequential electrode system can effectively destroy highly heat-resistant Bacillus cereus spores which have been frequently found in a commercial doenjang processing line without perceivable quality change in the product. In addition, it may demonstrate high potential of the unique OH system used in this study that will further contribute to ensure microbiological quality and safety of crude sauces containing high levels of electrolyte other than doenjang as well.

Small-Colony Variants in Persistent and Recurrent Staphylococcus aureus Bacteremia

The small-colony variant (SCV) phenotype of Staphylococcus aureus is associated with intracellular persistence and reduced antimicrobial susceptibility, which can lead to therapeutic failure. Since SCVs grow slowly and have a confusing morphology, the identification of infections due to SCV is difficult. We have identified SCVs in two patients who presented with persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia complicated by surgical site infections after cardiothoracic surgery. Nine blood isolates were collected from the two patients for species identification, antimicrobial susceptibility testing, and phenotypic and genotypic characterization. Colonies on Columbia blood agar were pinpoint, nonpigmented, nonhemolytic, and reverted to normal colonies after 48 hr of incubation on Schaedler agar. Auxotrophy assays revealed hemin dependence. Susceptibility to vancomycin (minimal inhibitory concentrations 1.0 μg/mL) was confirmed by E-test and broth microdilution test. All the isolates were identified as MRSA by multiplex polymerase chain reaction specific for the mecA, femA, and 16S rRNA genes, and all had the same genotype: Multilocus sequence typing ST5, SCCmec type II, agr type II, and spa type t2460. Moreover pulsed-field gel electrophoresis typing revealed that all nine isolates belonged to the same clone. Mutations in the relA gene were not found, and none of the isolates was identified as hVISA by population analysis profiling-AUC ratio. A high level of suspicion is required to detect SCVs, and although it is not common, the possibility of the SCV phenotype has to be considered in persistent S. aureus bacteremia.

Inactivation of Bacillus cereus spores in a tsuyu sauce using continuous ohmic heating with five sequential elbow-type electrodes

AIMS

The effect of ohmic heating (OH) in a pilot plant system which had a zig-zag shaped (elbow-type) ohmic heater with five sequential voltage electrodes was investigated on Bacillus cereus spores in a commercial tsuyu sauce.

METHODS AND RESULTS

The electrical field was fixed at 26·7 V cm(-1) with an alternating current frequency of 25 kHz. Raw tsuyu sauce (50 l) inoculated with B. cereus spores was submitted in a 4 × 3 factorial design to the OH system and heated at 95, 105, 115, and 125°C each for 30, 60, and 90 s. Survival of B. cereus spores and colour change in the commercial tsuyu sauce were both measured before and after treatment. As the treatment temperature and time increased, the number of surviving B. cereus spores decreased. The OH treatment in a bath-type process at 105°C for more than 30 s resulted in the total inactivation of the inoculated B. cereus spores (average 5·4 log reductions to undetectable levels after treatment). The OH protocol of heating at 105°C for 60 s which ensure complete eradication of the inoculated spores without compromising product quality was chosen and investigated for its suitability for commercial application on bulk quantities of samples (500 l). Reliable and reproducible reductions in B. cereus spore counts of 4·7-5·5 log CFU ml(-1) (mean ± standard deviation = 5·1 ± 0·3 CFU ml(-1) ) were achieved by the selected protocol of the continuous OH treatment (105°C for 60 s).

CONCLUSION

This study suggests that OH treatment with five sequential elbow-type electrodes has great potential as an industrial sterilizing method for liquid food contaminated with B. cereus spores.

SIGNIFICANCE AND IMPACT OF THE STUDY

This procedure will enhance the microbiological quality of liquid foods while minimizing quality deterioration.

Changes in the Microbial Composition of Microbrewed Beer during the Process in the Actual Manufacturing Line

This study investigated changes in the microbial composition of microbrewed beer during the manufacturing processes and identified potential microbial hazards, effective critical quality control points, and potential contamination routes. Comprehensive quantitative (aerobic plate count, lactic acid bacteria, fungi, acetic acid bacteria, coliforms, and Bacillus cereus) and qualitative (Escherichia coli and eight foodborne pathogens) microbiological analyses were performed using samples of raw materials (malt and manufacturing water), semiprocessed products (saccharified wort, boiled wort, and samples taken during the fermentation and maturation process), and the final product obtained from three plants. The initial aerobic plate count and lactic acid bacteria counts in malt were 5.2 and 4.3 log CFU/g, respectively. These counts were reduced to undetectable levels by boiling but were present at 2.9 and 0.9 log CFU/ml in the final product. Fungi were initially present at 3.6 log CFU/g, although again, the microbes were eliminated by boiling; however, the level in the final product was 4.6 log CFU/ml. No E. coli or foodborne pathogens (except B. cereus) were detected. B. cereus was detected at all stages, although it was not present in the water or boiled wort (total detection rate ¼ 16.4%). Results suggest that boiling of the wort is an effective microbial control measure, but careful management of raw materials and implementation of effective control measures after boiling are needed to prevent contamination of the product after the boiling step. The results of this study may constitute useful and comprehensive information regarding the microbiological quality of microbrewed beer.

Associations between Metabolic Syndrome and Inadequate Sleep Duration and Skipping Breakfast

Background

The prevalence of metabolic syndrome is increasing worldwide, and previous studies have shown that inadequate sleep duration and skipping breakfast may be related to metabolic syndrome. Therefore, we investigated the effects of inadequate sleep and skipping breakfast on metabolic syndrome using data from the Korea National Health and Nutrition Examination Survey (KNHANES) IV & V reports (2007-2009 and 2010-2012, respectively).

Methods

The sample included 12,999 subjects who participated in the KNHANES IV & V. Sleep duration and breakfast eating were self-reported, and metabolic syndrome was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III guidelines. Subjects were divided into 12 groups according to breakfast eating and sleep duration patterns, and multiple logistic regression analyses adjusted for age, sex, household income, education level, smoking status, alcohol drinking, physical activity, and total daily energy intake were conducted.

Results

In subjects under 50 years of age, sleeping less than 6 hours was significantly associated with increased metabolic syndrome except among those who ate breakfast on only 1 of the past 2 days. In subjects over 50 years of age, sleeping less than 6 hours was significantly associated with a decreased risk of metabolic syndrome among those who ate breakfast on both days.

Conclusion

In conclusion, significant associations between metabolic syndrome and sleep duration were identified, and these associations differed according to age group.

Why is asymptomatic bacteriuria overtreated?: A tertiary care institutional survey of resident physicians

Background

Asymptomatic bacteriuria (ABU) is common and often leads to unnecessary antimicrobial use. Reducing antibiotic overuse for ABU is therefore an important issue for antimicrobial stewardship. We performed this study to investigate the appropriateness of ABU management and to evaluate physicians’ knowledge and practice regarding ABU.

Methods

We reviewed all urine cultures of ≥10⁵ cfu/mL of bacteria among inpatients in a 900-bed hospital in 2011. Each episode of bacteriuria was classified into ABU or urinary tract infection (UTI). ABU was defined as a positive urine culture (≥10⁵ cfu/mL) without symptoms or signs suggesting UTI. In October 2012 a cross-sectional survey of resident physicians was undertaken using an anonymous, self-administered questionnaire.

Results

We identified 219 ABU cases among 1167 positive urine cultures, of which 70 (32.0 %) were inappropriately treated. Female gender, old age, pyuria, hematuria, and positive nitrite on urinalysis were associated with inappropriate ABU treatment in a multivariate analysis (P < 0.05).

The response rate to the survey was 74.2 % (95/128). The mean knowledge score was 37.3 %, and 33.7 % of respondents were able to distinguish ABU from UTI, but less than half knew the indications for treating ABU. Even after ABU was correctly diagnosed, concerns about postoperative infections (38.6 %), UTI (9.1 %), and abnormal urinalysis (29.5 %) prevented proper management. About half of the respondents reported to prescribing antibiotics for ABU despite knowing they were not indicated.

Conclusions

About one third of ABUs were inappropriately managed. Lack of knowledge and discrepancies between knowledge and practice, contributed to antimicrobial overuse for ABU. Our findings highlight the importance of developing interventions, including education, audit and feedback, to tackle the problem of inappropriate treatment of ABU.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1044-3) contains supplementary material, which is available to authorized users.

Metabolic stress induces a Wnt-dependent cancer stem cell-like state transition

Reciprocal interactions between cancer cells and the tumor microenvironment drive multiple clinically significant behaviors including dormancy, invasion, and metastasis as well as therapy resistance. These microenvironment-dependent phenotypes share typical characteristics with cancer stem cells (CSC). However, it is poorly understood how metabolic stress in the confined tumor microenvironment contributes to the emergence and maintenance of CSC-like phenotypes. Here, we demonstrate that chronic metabolic stress (CMS) in a long-term nutrient deprivation induces a Wnt-dependent phenoconversion of non-stem cancer cells toward stem-like state and this is reflected in the transcriptome analysis. Addition of Wnt3a as well as transfection of dominant-negative Tcf4 establishes an obligatory role for the Wnt pathway in the acquisition of CSC-like characteristics in response to metabolic stress. Furthermore, systematic characterization for multiple single cell-derived clones and negative enrichment of CD44+/ESA+ stem-like cancer cells, all of which recapitulate stem-like cancer characteristics, suggest stochastic adaptation rather than selection of pre-existing subclones. Finally, CMS in the tumor microenvironment can drive a CSC-like phenoconversion of non-stem cancer cells through stochastic state transition dependent on the Wnt pathway. These findings contribute to an understanding of the metabolic stress-driven dynamic transition of non-stem cancer cells to a stem-like state in the tumor metabolic microenvironment.

Human granulocytic anaplasmosis, South Korea, 2013

We report a patient with human granulocytic anaplasmosis in South Korea. The patient had fever and thrombocytopenia. Human granulocytic anaplasmosis was confirmed by seroconversion, PCR, and sequence analysis for Anaplasma phagocytophilum. Morulae were observed in the cultured HL-60 cells inoculated with blood from the patient.

Discrepancy in perceptions regarding patient participation in hand hygiene between patients and health care workers

BACKGROUND

Patient participation in hand hygiene programs is regarded as an important component of hand hygiene improvement, but the feasibility of the program is still largely unknown. We examined the perceptions of patients/families and health care workers (HCWs) with regard to patient participation in hand hygiene.

METHODS

A cross-sectional survey of patients/families as well as physicians and nurses was performed using an anonymous, self-administered questionnaire in a 1,000-bed teaching hospital in South Korea.

RESULTS

A total of 152 physicians, 387 nurses, and 334 patients/families completed the survey. The overall response rate was 84%, 85%, and more than 60% among physicians, nurses, and patients/families, respectively. Whereas 75% of patients/families wished to ask HCWs to clean their hands if they did not do so themselves, only 26% of physicians and 31% of nurses supported the participation of patients (P < .001). The most common reason why HCWs disagreed with patient participation was concern about negative effects on their relationship with patients (54%). Regarding the method of patient involvement, patients preferred to assess hand hygiene performance, whereas physicians preferred patients to ask directly.

CONCLUSIONS

There was a significant discrepancy in perceptions regarding patient participation between patients/families and HCWs. Enhanced understanding and acceptance of any new program by both patients and HCWs before its introduction are needed for successful implementation.

Successful containment of carbapenem-resistant Enterobacteriaceae by strict contact precautions without active surveillance

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) are a growing problem worldwide. Guidelines focus on carbapenemase-producing organisms, and little is known about whether strict adherence to infection control measures is effective for CRE without carbapenemase. During 2009, CRE increased markedly in a tertiary hospital, and enhanced infection control measures without active surveillance were adopted.

METHODS

Beginning in April 2010, enhanced antimicrobial stewardship, strict contact precautions, and cohort isolation were adopted. After September 2010, hand hygiene performance was prospectively monitored by active surveillance, and results were monthly fed back to medical personnel. Available carbapenem-resistant Escherichia coli (ECO) and carbapenem-resistant Klebsiella pneumoniae (KPN) isolated during 2008-2010 were characterized. Imipenem and meropenem minimal inhibitory concentrations were confirmed by E-test (AB biodisk, Solna, Sweden). Phenotypic screening assays and polymerase chain reaction (PCR) amplification of known β-lactamase and carbapenemase genes were performed.

RESULTS

From 3,511 ECO and 2,279 KPN, 44 (0.76%) were CRE (3 ECO, 41 KPN). CRE incidence rates rose from 1.61 in 2008 to 5.49 in 2009; they rose further to 9.81 per 100,000 patient days in early 2010. After adoption of strict infection control measures, CRE frequency fell back in 2011 and remained at baseline afterward. Phenotypic screening and PCR showed AmpC β-lactamase and extended spectrum β-lactamases with or without loss of porins; carbapenemases were not detected.

CONCLUSION

Enhanced infection control measures, even without active surveillance, seem effective to prevent further spread of CRE in a low-prevalence setting with mainly carbapenemase-nonproducing CRE.

Severe fever with thrombocytopenia syndrome, South Korea, 2012

We report a retrospectively identified fatal case of severe fever with thrombocytopenia syndrome (SFTS) in South Korea from 2012. SFTS virus was isolated from the stored blood of the patient. Phylogenetic analysis revealed this isolate was closely related to SFTS virus strains from China and Japan.

Clinical outcomes of spontaneous bacterial peritonitis due to extended-spectrum beta-lactamase-producing Escherichia coli or Klebsiella pneumoniae: a retrospective cohort study

PURPOSE

The aim of this study was to (1) evaluate the clinical outcomes of spontaneous bacterial peritonitis (SBP) due to extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli or Klebsiella pneumoniae (EK) and (2) investigate the relationship between the adequacy of initial antibiotic treatments and patient outcomes.

METHODS

We conducted a retrospective cohort study of cirrhotic patients with SBP caused by EK. We evaluated the 30-day mortality rate and used Cox proportional hazard models to identify risk factors for mortality.

RESULTS

Between January 2006 and December 2012, a total of 231 episodes of SBP due to EK were recorded. Among them, 52 were caused by ESBL-producing EK (ESBL-EK). The 30-day mortality rate was significantly higher in patients with SBP due to ESBL-EK than in those with non-ESBL-producing EK (non-ESBL-EK) (34.6 vs. 18.4 %, respectively; p = 0.013). Multivariate analysis revealed that ESBL production [adjusted HR (aHR) 1.82, 95 % confidence interval (CI) 1.00-3.31], nosocomial infection (aHR 2.24, 95 % CI 1.26-3.95), septic shock (aHR 4.84, 95 % CI 2.70-8.65), higher Child-Pugh score (aHR 1.57, 95 % CI 1.28-1.92), and higher Charlson comorbidity index (aHR 1.37, 95 % CI 1.15-1.64) were independent risk factors for 30-day mortality in the total cohort. When we analyzed patients with SBP due to ESBL-EK separately, septic shock (aHR 3.64, 95 % CI 1.40-9.77), accompanying bacteremia (aHR 3.71, 95 % CI 1.37-10.08), and hepatocellular carcinoma (aHR 3.21, 95 % CI 1.20-8.56) were independent risk factors.

CONCLUSIONS

Both 7- and 30-day mortalities for SBP due to ESBL-EK were significantly higher than for SBP due to non-ESBL-EK. Initial antibiotic choice was not associated with poor clinical outcomes in patients with SBP due to ESBL-EK.

Enhanced bactericidal action of acidified sodium chlorite caused by the saturation of reactants

AIMS

Factors affecting the antibacterial action of acidified sodium chlorite (ASC), a widely used disinfectant, have not been determined. This study investigated the significant factors suggesting efficient production method to maximize bactericidal action of ASC.

METHODS AND RESULTS

The effects of (i) preparation procedures (total three methods); (ii) initial concentrations of reactants: sodium chlorite (SC) and citric acid (CTA) (up to maximum solubility of each reactant) and (iii) final pH values (3·0 and 2·5) to the bactericidal action of ASC were investigated with a fixed final concentration of SC (10 ppm) using various foodborne pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium and Staphylococcus aureus). The antimicrobial compounds produced and the bactericidal effects depended on the preparation procedure and the initial concentrations of the reactants. The ASC prepared by premixing highly concentrated reactants (in particular > 40%) followed by dilution (dilution after reaction, DAR) was more effective in inactivating foodborne pathogens, and it produced higher antimicrobial compound (Cl(2) and ClO(2)) yields than the other procedures. A 5-min treatment with ASC, produced using the other procedures, resulted in a reduction of < 3·5 log CFU ml(-1) (Gram positive = 0·18-0·78; Gram negative = 0·03-3·49 log CFU ml(-1)), whereas ASC produced with the DAR procedure using the saturated reactants completely inactivated all of the test pathogens within 5 min without recovery (initial concentration = 6·94-7·08 log CFU ml(-1)).

CONCLUSION

The ASC production with the DAR procedure using the saturated reactants maximizes both the antimicrobial compound yields and bactericidal effects of the ASC solutions.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study will contribute to increase the efficiency of ASC treatments for disinfections reducing the effective SC concentrations for industrial use.