Characterization of resistance to newer antimicrobials among carbapenem-resistant Klebsiella pneumoniae in the post-acute-care setting

We assessed susceptibility patterns to newer antimicrobial agents among clinical carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates from patients in long-term acute-care hospitals (LTACHs) from 2014 to 2015. Meropenem-vaborbactam and imipenem-relebactam nonsusceptibility were observed among 9.9% and 9.1% of isolates, respectively. Nonsusceptibility to ceftazidime-avibactam (1.1%) and plazomicin (0.8%) were uncommon.

[Deepening the Action on Salt Reduction in China-suggestions on strategy and implementation plan]

Excessive sodium/salt intake is the leading dietary risk factor for the loss of healthy life in the Chinese population. The "Healthy China 2030" Action Plan set the goal of reducing salt intake by 20% by 2030. However, salt intake in China is still at a very high level in the world, with adults reaching 11 g/d, more than twice the recommended limit of 5 g/d. The current policies and action plans of China have targeted catering workers, children, adolescents, and home chefs in salt, oil, and sugar reduction actions. However, there are still obvious deficiencies in the coordinated promotion and implementation. This study, therefore, proposed a set of comprehensive strategies (named CHRPS that is composed of communication and education, salt reduction in home cooking, salt reduction in restaurants, reducing salt content in pre-packaged food, and surveillance and evaluation) and key implementation points for further deepening the salt reduction action in China. These strategies were developed based on the main sources of dietary sodium for Chinese residents, the status of"knowledge, attitude and practice"in salt reduction, evidence of effective intervention measures, existing policies and requirements, and the salt reduction strategies of the World Health Organization and experience from some other countries. As a scientific reference, the CHRPS strategies will help the government and relevant organizations quickly implement salt reduction work and facilitate the earlier realization of China's salt reduction goal.

Clinical Outcomes and Risk Factors for Carbapenem-resistant Enterobacterales Bloodstream Infection in Solid Organ Transplant Recipients

BACKGROUND

The clinical outcomes associated with, and risk factors for, carbapenem-resistant Enterobacterales (CRE) bloodstream infections (BSIs) in solid organ transplant (SOT) recipients remain ill-defined.

METHODS

A multicenter retrospective cohort study was performed, including SOT recipients with an Enterobacterales BSI between 2005 and 2018. Exposed subjects were those with a CRE BSI. Unexposed subjects were those with a non-CRE BSI. A multivariable survival analysis was performed to determine the association between CRE BSI and risk of all-cause mortality within 60 d. Multivariable logistic regression analysis was performed to determine independent risk factors for CRE BSI.

RESULTS

Of 897 cases of Enterobacterales BSI in SOT recipients, 70 (8%) were due to CRE. On multivariable analysis, CRE BSI was associated with a significantly increased hazard of all-cause mortality (adjusted hazard ratio, 2.85; 95% confidence interval [CI], 1.68-4.84; P < 0.001). Independent risk factors for CRE BSI included prior CRE colonization or infection (adjusted odds ratio [aOR] 9.86; 95% CI, 4.88-19.93; P < 0.001)' liver transplantation (aOR, 2.64; 95% CI, 1.23-5.65; P = 0.012)' lung transplantation (aOR, 3.76; 95% CI, 1.40-10.09; P = 0.009)' and exposure to a third-generation cephalosporin (aOR, 2.21; 95% CI, 1.17-4.17; P = 0.015) or carbapenem (aOR, 2.80; 95% CI, 1.54-5.10; P = 0.001) in the prior 6 months.

CONCLUSIONS

CRE BSI is associated with significantly worse outcomes than more antibiotic-susceptible Enterobacterales BSI in SOT recipients.

The global burden of sudden infant death syndrome from 1990 to 2019: a systematic analysis from the Global Burden of Disease study 2019

BACKGROUND

Sudden infant death syndrome (SIDS) still remains one of the leading causes of infant death worldwide, especially in high-income countries. To date, however, there is no detailed information on the global health burden of SIDS.

AIMS

To characterize the global disease burden of SIDS and its trends from 1990 to 2019 and to compare the burden of SIDS according to the socio-demographic index (SDI).

DESIGN

Systematic analysis based on the Global Burden of Disease (GBD) 2019 data.

METHODS

Epidemiological data of 204 countries from 1990 to 2019 were collected via various methods including civil registration and vital statistics in the original GBD study. Estimates for mortality and disease burden of SIDS were modeled. Crude mortality and mortality rates per 100 000 population were analyzed. Disability-adjusted life years (DALYs) and DALY rates were also assessed.

RESULTS

In 2019, mortality rate of SIDS accounted for 20.98 [95% Uncertainty Interval, 9.15-46.16] globally, which was a 51% decrease from 1990. SIDS was most prevalent in Western sub-Saharan Africa, High-income North America and Oceania in 2019. The burden of SIDS was higher in males than females consistently from 1990 to 2019. Higher SDI and income level was associated with lower burden of SIDS; furthermore, countries with higher SDI and income had greater decreases in SIDS burden from 1990 to 2019.

CONCLUSIONS

The burden of SIDS has decreased drastically from 1990 to 2019. However, the improvements have occurred disproportionately between regions and SDI levels. Focused preventive efforts in under-resourced populations are needed.

Risk Factors for Colistin-Resistant Carbapenem-Resistant Klebsiella pneumoniae in the Postacute Care Setting

We assessed risk factors for colistin resistance among carbapenem-resistant Klebsiella pneumoniae (CRKP) from 375 patients in long-term acute care hospitals. Recent colistin or polymyxin B exposure was associated with increased odds of colistin resistance (adjusted odds ratio = 1.11 per day of exposure, 95% confidence interval = 1.03-1.19, P = .007).

Analysis of synthetic electron cyclotron emission from the high field side of HL-2M tokamak plasmas

A synthetic electron cyclotron emission (ECE) diagnostic is used to interpret ECE signals from preset plasma equilibrium profiles, including magnetic field, electron density, and electron temperature. According to the simulation results, the electron temperature (T_e) profile covering the harmonic overlap region can be obtained by receiving ECE signals at the high field side (HFS) of the HL-2M plasma. The third harmonic ECE at the low field side (LFS) cannot pass through the second harmonic resonance layer at the HFS unless the optical thickness (τ) of the second harmonic becomes gray (τ ≤ 2). In addition, the impact of the relativistic frequency down-shift has been evaluated and corrected. The measurable range of the HFS ECE has been calculated by scanning different parameters (electron density, temperature, and magnetic field). Higher plasma parameters allow a wider radial range of electron temperature measurements. The minimum inner measurable position can reach R = 120 cm (r/a = -0.89) when the product of core temperature (T_e0) and density (n_e0) is greater than 35 × 10¹⁹ keV m^-3, which is extended by more than 30 cm inward compared with that of the LFS measurement. The HFS ECE will greatly improve the diagnostic ability of ECE systems on the HL-2M tokamak.

Impact of donor multidrug-resistant organisms on solid organ transplant recipient outcomes

BACKGROUND

The impact of donor colonization or infection with multidrug-resistant organisms (MDROs) on solid organ transplant (SOT) recipient outcomes remains uncertain. We thus evaluated the association between donor MDROs and risk of posttransplant infection, graft failure, and mortality.

METHODS

A multicenter retrospective cohort study was performed. All SOT recipients with a local deceased donor were included. The cohort was divided into three exposure groups: recipients whose donors had (1) an MDRO, (2) a non-MDRO bacterial or candidal organism, or (3) no growth on cultures. The primary outcomes were (1) bacterial or invasive candidal infection within 3 months and (2) graft failure or death within 12 months posttransplant. Mixed effect multivariable frailty models were developed to evaluate each association.

RESULTS

Of 658 total SOT recipients, 93 (14%) had a donor with an MDRO, 477 (73%) had a donor with a non-MDRO organism, and 88 (13%) had a donor with no organisms on culture. On multivariable analyses, donor MDROs were associated with a significantly increased hazard of infection compared to those with negative donor cultures (adjust hazard ratio [aHR] 1.63, 95% CI 1.01-2.62, p = .04) but were not associated with graft failure or death (aHR 0.45, 95% CI 0.15-1.36, p = .16).

CONCLUSIONS

MDROs on donor culture increase the risk of early posttransplant infection but do not appear to affect long-term graft or recipient survival, suggesting organ donors with MDROs on culture may be safely utilized. Future studies aimed at reducing early posttransplant infections associated with donor MDROs are needed.

Stopping Hospital Infections With Environmental Services (SHINE): A Cluster-randomized Trial of Intensive Monitoring Methods for Terminal Room Cleaning on Rates of Multidrug-resistant Organisms in the Intensive Care Unit

BACKGROUND

Multidrug-resistant organisms (MDROs) frequently contaminate hospital environments. We performed a multicenter, cluster-randomized, crossover trial of 2 methods for monitoring of terminal cleaning effectiveness.

METHODS

Six intensive care units (ICUs) at 3 medical centers received both interventions sequentially, in randomized order. Ten surfaces were surveyed each in 5 rooms weekly, after terminal cleaning, with adenosine triphosphate (ATP) monitoring or an ultraviolet fluorescent marker (UV/F). Results were delivered to environmental services staff in real time with failing surfaces recleaned. We measured monthly rates of MDRO infection or colonization, including methicillin-resistant Staphylococcus aureus, Clostridioides difficile, vancomycin-resistant Enterococcus, and MDR gram-negative bacilli (MDR-GNB) during a 12-month baseline period and sequential 6-month intervention periods, separated by a 2-month washout. Primary analysis compared only the randomized intervention periods, whereas secondary analysis included the baseline.

RESULTS

The ATP method was associated with a reduction in incidence rate of MDRO infection or colonization compared with the UV/F period (incidence rate ratio [IRR] 0.876; 95% confidence interval [CI], 0.807-0.951; P = .002). Including the baseline period, the ATP method was associated with reduced infection with MDROs (IRR 0.924; 95% CI, 0.855-0.998; P = .04), and MDR-GNB infection or colonization (IRR 0.856; 95% CI, 0.825-0.887; P < .001). The UV/F intervention was not associated with a statistically significant impact on these outcomes. Room turnaround time increased by a median of 1 minute with the ATP intervention and 4.5 minutes with UV/F compared with baseline.

CONCLUSIONS

Intensive monitoring of ICU terminal room cleaning with an ATP modality is associated with a reduction of MDRO infection and colonization.

Clinical prediction tool for extended-spectrum beta-lactamase-producing enterobacterales as the etiology of a bloodstream infection in solid organ transplant recipients

BACKGROUND

Multidrug-resistant Gram-negative bacterial infections are increasingly common among solid organ transplant (SOT) recipients, leading to challenges in the selection of empiric antimicrobial therapy. We sought to develop a clinical tool to predict which SOT recipients are at high risk for extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (EB) bloodstream infection (BSI).

METHODS

A multicenter case-control study was performed. The source population included SOT recipients with an EB BSI between 2005 and 2018. Cases were those with ESBL-EB BSI; controls were those with non-ESBL EB BSI. The population was subdivided into derivation and validation cohorts based on study site. The predictive tool was developed in the derivation cohort through iterative multivariable logistic regression analyses that maximized the area under the receiver-operating curve (AUC). External validity was assessed using the validation cohort.

RESULTS

A total of 897 SOT recipients with an EB BSI were included, of which 539 were assigned to the derivation cohort (135, 25% ESBL-EB) and 358 to the validation cohort (221, 62% ESBL-EB). Using multivariable analyses, the most parsimonious model that was predictive of ESBL-EB BSI consisted of 10 variables, which fell into four clinical categories: prior colonization or infection with EB organisms, recent antimicrobial exposures, severity of preceding illness, and immunosuppressive regimen. This model achieved an AUC of 0.81 in the derivation cohort and 0.68 in the validation cohort.

CONCLUSIONS

Though further refinements are needed in additional populations, this tool shows promise for guiding empiric therapy for SOT recipients with EB BSI.

Increased viral variants in children and young adults with impaired humoral immunity and persistent SARS-CoV-2 infection: A consecutive case series

BACKGROUND

There is increasing concern that persistent infection of SARS-CoV-2 within immunocompromised hosts could serve as a reservoir for mutation accumulation and subsequent emergence of novel strains with the potential to evade immune responses.

METHODS

We describe three patients with acute lymphoblastic leukemia who were persistently positive for SARS-CoV-2 by real-time polymerase chain reaction. Viral viability from longitudinally-collected specimens was assessed. Whole-genome sequencing and serological studies were performed to measure viral evolution and evidence of immune escape.

FINDINGS

We found compelling evidence of ongoing replication and infectivity for up to 162 days from initial positive by subgenomic RNA, single-stranded RNA, and viral culture analysis. Our results reveal a broad spectrum of infectivity, host immune responses, and accumulation of mutations, some with the potential for immune escape.

INTERPRETATION

Our results highlight the potential need to reassess infection control precautions in the management and care of immunocompromised patients. Routine surveillance of mutations and evaluation of their potential impact on viral transmission and immune escape should be considered.

Risk Factors for Extended-Spectrum β-lactamase-Producing Enterobacterales Bloodstream Infection Among Solid-Organ Transplant Recipients

BACKGROUND

Approximately 40% of all Enterobacterales (EB) bloodstream infections (BSIs) among solid organ transplant recipients (SOTRs) are due to extended-spectrum β-lactamase (ESBL)-producing organisms, but risk factors for such infections remain ill defined in this population. We sought to determine the risk factors for ESBL-EB BSIs among SOTRs.

METHODS

A multicenter case-control study was performed. All SOTRs with an EB BSI at the Hospital of the University of Pennsylvania and University of Maryland Medical Center between 1 January 2007 and 30 June 2018 and at The Johns Hopkins Hospital between 1 January 2005 and 31 December 2015 were included. Cases were those with an ESBL-EB BSI. Controls were those with a non-ESBL-EB BSI. Multivariable logistic regression was performed to determine risk factors for ESBL-EB BSI.

RESULTS

There were 988 episodes of EB BSI, of which 395 (40%) were due to an ESBL-EB. On multivariable analysis, the independent risk factors for ESBL-EB BSI included: ESBL-EB on prior culture (aOR, 12.75; 95% CI, 3.23-50.33; P < .001), a corticosteroid-containing immunosuppression regimen (aOR 1.30; 95% CI 1.03-1.65; P = .030), acute rejection treated with corticosteroids (aOR 1.18; 95% CI 1.16-1.19; P < .001), and exposure to third-generation cephalosporins (aOR 1.95; 95% CI 1.48-2.57; P < .001), echinocandins (aOR 1.61; 95% CI 1.08-2.40; P = .020), and trimethoprim-sulfamethoxazole (aOR 1.35; 95% CI 1.10-1.64; P = .003).

CONCLUSIONS

We identified several novel risk factors that are uniquely important to the SOTR population, including exposure to trimethoprim-sulfamethoxazole and corticosteroid-containing immunosuppressive regimens. Further studies exploring these associations and testing interventions aimed at these modifiable risk factors among SOTRs are needed.

Comparing Propensity Score Methods Versus Traditional Regression Analysis for the Evaluation of Observational Data: A Case Study Evaluating the Treatment of Gram-Negative Bloodstream Infections

BACKGROUND

Propensity score methods are increasingly being used in the infectious diseases literature to estimate causal effects from observational data. However, there remains a general gap in understanding among clinicians on how to critically review observational studies that have incorporated these analytic techniques.

METHODS

Using a cohort of 4967 unique patients with Enterobacterales bloodstream infections, we sought to answer the question "Does transitioning patients with gram-negative bloodstream infections from intravenous to oral therapy impact 30-day mortality?" We conducted separate analyses using traditional multivariable logistic regression, propensity score matching, propensity score inverse probability of treatment weighting, and propensity score stratification using this clinical question as a case study to guide the reader through (1) the pros and cons of each approach, (2) the general steps of each approach, and (3) the interpretation of the results of each approach.

RESULTS

2161 patients met eligibility criteria with 876 (41%) transitioned to oral therapy while 1285 (59%) remained on intravenous therapy. After repeating the analysis using the 4 aforementioned methods, we found that the odds ratios were broadly similar, ranging from 0.84-0.95. However, there were some relevant differences between the interpretations of the findings of each approach.

CONCLUSIONS

Propensity score analysis is overall a more favorable approach than traditional regression analysis when estimating causal effects using observational data. However, as with all analytic methods using observational data, residual confounding will remain; only variables that are measured can be accounted for. Moreover, propensity score analysis does not compensate for poor study design or questionable data accuracy.

Patient and Microbial Genomic Factors Associated with Carbapenem-Resistant Klebsiella pneumoniae Extraintestinal Colonization and Infection

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a critical-priority antibiotic resistance threat that has emerged over the past several decades, spread across the globe, and accumulated resistance to last-line antibiotic agents. While CRKP infections are associated with high mortality, only a subset of patients acquiring CRKP extraintestinal colonization will develop clinical infection. Here, we sought to ascertain the relative importance of patient characteristics and CRKP genetic background in determining patient risk of infection. Machine learning models classifying colonization versus infection were built using whole-genome sequences and clinical metadata from a comprehensive set of 331 CRKP extraintestinal isolates collected across 21 long-term acute-care hospitals over the course of a year. Model performance was evaluated based on area under the receiver operating characteristic curve (AUROC) on held-out test data. We found that patient and genomic features were predictive of clinical CRKP infection to similar extents (AUROC interquartile ranges [IQRs]: patient = 0.59 to 0.68, genomic = 0.55 to 0.61, combined = 0.62 to 0.68). Patient predictors of infection included the presence of indwelling devices, kidney disease, and length of stay. Genomic predictors of infection included presence of the ICEKp10 mobile genetic element carrying the yersiniabactin iron acquisition system and disruption of an O-antigen biosynthetic gene in a sublineage of the epidemic ST258 clone. Altered O-antigen biosynthesis increased association with the respiratory tract, and subsequent ICEKp10 acquisition was associated with increased virulence. These results highlight the potential of integrated models including both patient and microbial features to provide a more holistic understanding of patient clinical trajectories and ongoing within-lineage pathogen adaptation.IMPORTANCE Multidrug-resistant organisms, such as carbapenem-resistant Klebsiella pneumoniae (CRKP), colonize alarmingly large fractions of patients in regions of endemicity, but only a subset of patients develop life-threatening infections. While patient characteristics influence risk for infection, the relative contribution of microbial genetic background to patient risk remains unclear. We used machine learning to determine whether patient and/or microbial characteristics can discriminate between CRKP extraintestinal colonization and infection across multiple health care facilities and found that both patient and microbial factors were predictive. Examination of informative microbial genetic features revealed variation within the ST258 epidemic lineage that was associated with respiratory tract colonization and increased rates of infection. These findings indicate that circulating genetic variation within a highly prevalent epidemic lineage of CRKP influences patient clinical trajectories. In addition, this work supports the need for future studies examining the microbial genetic determinants of clinical outcomes in human populations, as well as epidemiologic and experimental follow-ups of identified features to discern generalizability and biological mechanisms.

Persistent SARS-CoV-2 infection and increasing viral variants in children and young adults with impaired humoral immunity

Background

There is increasing concern that persistent infection of SARS-CoV-2 within immunocompromised hosts could serve as a reservoir for mutation accumulation and subsequent emergence of novel strains with the potential to evade immune responses.

Methods

We describe three patients with acute lymphoblastic leukemia who were persistently positive for SARS-CoV-2 by real-time polymerase chain reaction. Viral viability from longitudinally-collected specimens was assessed. Whole-genome sequencing and serological studies were performed to measure viral evolution and evidence of immune escape.

Findings

We found compelling evidence of ongoing replication and infectivity for up to 162 days from initial positive by subgenomic RNA, single-stranded RNA, and viral culture analysis. Our results reveal a broad spectrum of infectivity, host immune responses, and accumulation of mutations, some with the potential for immune escape.

Interpretation

Our results highlight the need to reassess infection control precautions in the management and care of immunocompromised patients. Routine surveillance of mutations and evaluation of their potential impact on viral transmission and immune escape should be considered.

Funding

The work was partially funded by The Saban Research Institute at Children's Hospital Los Angeles intramural support for COVID-19 Directed Research (X.G. and J.D.B.), the Johns Hopkins Center of Excellence in Influenza Research and Surveillance HHSN272201400007C (A.P.), NIH/NIAID R01AI127877 (S.D.B.), NIH/NIAID R01AI130398 (S.D.B.), NIH 1U54CA260517 (S.D.B.), an endowment to S.D.B. from the Crown Family Foundation, an Early Postdoc.Mobility Fellowship Stipend to O.F.W. from the Swiss National Science Foundation (SNSF), and a Coulter COVID-19 Rapid Response Award to S.D.B. L.G. is a SHARE Research Fellow in Pediatric Hematology-Oncology.

Molecular and phenotypic diversity of CBL-mutated juvenile myelomonocytic leukemia

Mutations in the CBL gene were first identified in adults with various myeloid malignancies. Some patients with juvenile myelomonocytic leukemia (JMML) were also noted to harbor mutations in CBL, but were found to have generally less aggressive disease courses compared to patients with other forms of Ras pathway-mutant JMML. Importantly, and in contrast to most reports in adults, the majority of CBL mutations in JMML patients are germline with acquired uniparental disomy occurring in affected marrow cells. Here, we systematically studied a large cohort of 33 JMML patients with CBL mutations and found that this disease is highly diverse in presentation and overall outcome. Moreover, we discovered somatically acquired CBL mutations in 15% of pediatric patients who presented with more aggressive disease. Neither clinical features nor methylation profiling were able to distinguish patients with somatic CBL mutations from those with germline CBL mutations, highlighting the need for germline testing. Overall, we demonstrate that disease courses are quite heterogeneous even among patients with germline CBL mutations. Prospective clinical trials are warranted to find ideal treatment strategies for this diverse cohort of patients.

3D wide-field multispectral photoacoustic imaging of human melanomas in vivo: a pilot study

BACKGROUND

The Breslow depth is an important parameter to determine the excision margin and prognosis of melanoma. However, it is difficult to accurately determine the actual Breslow depth before surgery using the existing ocular micrometer and biopsy technique.

OBJECTIVES

To evaluate the use of 3D wide-field multispectral photoacoustic imaging to non-invasively measure depth and outline the boundary of melanomas for optimal surgical margin selection.

METHODS

Six melanoma patients were examined in vivo using the 3D multispectral photoacoustic imaging system. For five cases of melanomas (one in situ, three nodular, and one acral lentiginous type melanoma), the spectrally unmixed photoacoustic depths were calculated and compared against histopathological depths.

RESULTS

Spectrally unmixed photoacoustic depths and histopathological depths match well within a mean absolute error of 0.36 mm. In particular, the measured minimum and maximum depths in the in situ and nodular type of melanoma were 0.6 and 9.1 mm, respectively. In the 3D photoacoustic image of one metastatic melanoma, feeding vessels were visualized in the melanoma, suggesting the neovascularization around the tumour.

CONCLUSIONS

The 3D multispectral photoacoustic imaging not only provides well-measured depth and sizes of various types of melanomas, it also visualizes the metastatic type of melanoma. Obtaining accurate depth and boundary information of melanoma before surgery would play a useful role in the complete excision of melanoma during surgery.

Impact of deceased donor multidrug-resistant bacterial organisms on organ utilization

The extent to which donor multidrug-resistant organisms (MDROs) affect organ utilization remains unclear. We performed a retrospective cohort study at 4 transplant centers between 2015 and 2016 to evaluate this question. All deceased donors who donated at least one organ were included. Exposed donors had at least one MDRO on culture. Unexposed donors had no MDRO-positive cultures. Only cultures obtained during the donor's terminal hospitalization were evaluated. Multivariable regression was used to determine the association between donor MDRO and (1) number of organs transplanted per donor and (2) the match run at which each organ was accepted. Subsequently, we restricted the analysis to donors with MDR-Gram-negative (GN) organisms. Of 440 total donors, 29 (7%) donors grew MDROs and 7 (2%) grew MDR-GNs. There was no significant association between donor MDRO and either measure of organ utilization. However, donor MDR-GNs were associated with a significant reduction in the number of organs transplanted per donor (incidence rate ratio 0.43, 95% confidence interval [CI] 0.39-0.48, P < .01), and organs were accepted significantly further down the match list (relative count 5.08, 95% CI 1.64-15.68, P = .01). Though donor MDR-GNs were infrequent in our study, their growing prevalence could meaningfully reduce the donor pool over time.

Primary Presentation of Pediatric Hematopoietic Malignancy in the Temporal Bone: Case Report and Review of the Literature

Malignancy of hematopoietic origin comprises a large portion of all pediatric malignancies; however, it is uncommon for patients with this condition to present only with symptoms related to temporal bone involvement. Here, we report a case of Burkitt Lymphoma of the temporal bone in an 8-year-old patient who initially presented with symptoms of acute otitis media. Additionally, we review the current literature on pediatric hematopoietic malignancy with primary temporal bone involvement and discuss the clinical presentation, management, and outcomes of these rare cases.

Fate of the micropenis and constitutional small penis: do they grow to normalcy in puberty?

INTRODUCTION

Penile length is an important indicator of male sexual development. Scarce data were reported on penile length measurements in children comparing changes between prepuberty and puberty for the small penile issue with long-term follow-up.

OBJECTIVE

The purpose of this study was to investigate the possibility of catch-up growth of the penile length of boys with a small penis in the long-term follow-up.

STUDY DESIGN

From April 2001 to December 2016, 27 boys who visited the outpatient clinic owing to a small penis, without any chromosomal anomalies and other genital disorder, were investigated retrospectively. Micropenis is defined as 2.5 standard deviations less than the mean stretched penile length (SPL) of age. Periodic penile length, testicular volume, hormonal levels (serum testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH)), and bone age were measured. Pubertal development was recorded by using the Tanner scale. The effect of hormonal therapy and the factors attributable to the increment of the penile length were evaluated.

RESULTS

The mean age at the first visit was 9.8 years (5-12 years) and that at puberty was 12.6 years (10-16 years). The length of the penis at the initial visit was 4.0 ± 0.8 cm (2.5-6.0) and at puberty, 7.3 ± 1.8 cm (4.0-12.0). Nine patients diagnosed with micropenis no longer had a micropenis in puberty. The less the age-matched SPL, the more the increment of SPL that was observed (rho = - 0.548, P = 0.003). The mean increment of SPL in the hormonal therapy group (11 boys) and the non-hormonal therapy group (16 boys) was not statistically different (43.5 ± 22. 9% vs 41.5 ± 21.6%, respectively, P = 0.497).

DISCUSSION

This study explains how much the growth of a small penis catches up in puberty. From the point of view of the increment of SPL, the increment was higher in boys who belonged to the smaller penis group. Hormonal therapy does not attribute to an increase in the length after long-term follow-up. Limitations of this study were its retrospective origin with a small number of patients in a single center.

CONCLUSION

Catch-up growth of the small penis at puberty was accomplished in most children with a small penis before puberty. Hormonal treatment was not significantly correlated with the penile length increment in the long-term follow-up.

Risk factors for multidrug-resistant organisms among deceased organ donors

Donor infection or colonization with a multidrug-resistant organism (MDRO) affects organ utilization and recipient antibiotic management. Approaches to identifying donors at risk of carrying MDROs are unknown. We sought to determine the risk factors for MDROs among transplant donors. A multicenter retrospective cohort study was conducted at four transplant centers between 2015 and 2016. All deceased donors who donated at least one organ were included. Cultures obtained during the donor's terminal hospitalization and organ procurement were evaluated. The primary outcome was isolation of an MDRO on culture. Multivariable Cox regression was used to determine risk factors associated with time to donor MDRO. Of 440 total donors, 64 (15%) donors grew an MDRO on culture. Predictors of an MDRO on donor culture included hepatitis C viremia (hazard ratio [HR] 4.09, 95% confidence interval [CI] 1.71-9.78, P = .002), need for dialysis (HR 4.59, 95% CI 1.09-19.21, P = .037), prior hematopoietic cell transplant (HR 7.57, 95% CI 1.03-55.75, P = .047), and exposure to antibiotics with a narrow gram-negative spectrum (HR 1.13, 95% CI 1.00-1.27, P = .045). This is the first study to determine risk factors for MDROs among deceased donors and will be important for risk stratifying potential donors and informing transplant recipient prophylaxis.

Association between 18F-FDG uptake in PET/CT, Nrf2, and NQO1 expression and their prognostic significance in non-small cell lung cancer

Two pentose phosphate pathway-related proteins, NF-E2-related factor 2 (Nrf2)/ NAD(P)H dehydrogenase (Quinone) 1 (NQO1) regulate the expression of glucose metabolism and antioxidant genes. We evaluated the prognostic significance of NRF2, NQO1 and 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) parameter and their relationship with non-small cell lung cancer (NSCLC) histology. A total of 241 patients, who underwent surgical resection for NSCLC, were reviewed retrospectively. Preoperative 18F-FDG PET and immunohistochemical results of Nrf2 and NQO1 were evaluated. In SQCC, the maximum standardized uptake value (SUVmax) was significantly higher in NQO1-high than in NQO1-low expression (p=0.023). In adenocarcinoma, SUVmax was not correlated with NQO1 expression. Patients with a high NQO1 expression showed poor recurrence-free survival (RFS) and overall survival (OS) than patients with a low NQO1 expression in squamous cell carcinoma (SQCC) (p=0.002 and p=0.014, respectively). NQO1 expression was not associated with clinical outcome in adenocarcinoma. Nrf2 expression was not correlated with prognosis in two types of NSCLC. High SUVmax was associated with poor RFS (p=0.03) but is not related to poor OS (p=0.569) in SQCC. In multivariate analyses, NQO1 expression and SUVmax were not independent prognostic factors in SQCC. However, in multivariate analysis combining NQO1 and SUVmax values, both low SUVmax and low NQO1 was independent prognostic factor for RFS and OS (HR= 3.790, p = 0.033 and HR= 2.961, p = 0.045, respectively). In conclusion, both low SUVmax and low NQO1 was an independent prognostic factor in SQCC alone. The sample size was small but there was a positive correlation between NQO1 expression and SUVmax in SQCC.

Impact of Levofloxacin for the Prophylaxis of Bloodstream Infection on the Gut Microbiome in Patients With Hematologic Malignancy

Background

We evaluated the differential impact of levofloxacin administered for the prophylaxis of bloodstream infections compared with broad-spectrum beta-lactam (BSBL) antibiotics used for the treatment of neutropenic fever on the gut microbiome in patients with hematologic malignancy.

Methods

Stool specimens were collected from patients admitted for chemotherapy or stem cell transplant in the setting of the evaluation of diarrhea from February 2017 until November 2017. Microbiome characteristics were compared among those exposed to levofloxacin prophylaxis vs those who received BSBL antibiotics.

Results

Sixty patients were included, most with acute myeloid leukemia (42%) or multiple myeloma (37%). The gut microbiome of patients with BSBL exposure had significantly reduced Shannon's alpha diversity compared with those without (median [interquartile range {IQR}], 3.28 [1.73 to 3.71] vs 3.73 [3.14 to 4.31]; P = .01). However, those with levofloxacin exposure had increased alpha diversity compared with those without (median [IQR], 3.83 [3.32 to 4.36] vs 3.32 [2.35 to 4.02]; P = .03). Levofloxacin exposure was also associated with a trend toward lower risk of dominance of non-Bacteroidetes genera compared with those without levofloxacin exposure (3 [14%] vs 15 [38%]; P = .051).

Conclusions

The impact of antibiotics on the gut microbiome varies by class, and levofloxacin may disrupt the gut microbiome less than BSBLs in this patient population.

Oral Vancomycin Prophylaxis Is Highly Effective in Preventing Clostridium difficile Infection in Allogeneic Hematopoietic Cell Transplant Recipients

BACKGROUND

Clostridium difficile infection (CDI) is a leading cause of infectious complications in allogeneic hematopoietic cell transplant recipients (alloHCT). We sought to evaluate whether prophylactic oral vancomycin reduces the incidence of CDI in alloHCT recipients.

METHODS

We conducted a retrospective cohort study to examine the effectiveness of CDI prophylaxis with oral vancomycin, as compared to no prophylaxis, in 145 consecutive adult alloHCT recipients at the University of Pennsylvania between April 2015 and November 2016. Patients received oral vancomycin 125 mg twice daily, starting on admission and continuing until discharge. The primary outcome of interest was the association between oral vancomycin prophylaxis and CDI diagnosis. Secondary outcomes included graft-versus-host disease (GVHD) and relapse.

RESULTS

There were no cases of CDI in patients that received prophylaxis (0/90, 0%), whereas 11/55 (20%) patients who did not receive prophylaxis developed CDI (P < .001). Oral vancomycin prophylaxis was not associated with a higher risk of acute, grades 2-4 GVHD (subhazard ratio [sHR] 1.59; 95% confidence interval [CI] 0.88-2.89; P = .12), acute, grades 3-4 GVHD (sHR 0.65; 95% CI 0.25-1.66; P = .36), or acute, grades 2-4 gastrointestinal GVHD (sHR 1.95; 95% CI 0.93-4.07; P = .08) at day 180 post-transplant. No associations between oral vancomycin and relapse or survival were observed.

CONCLUSIONS

Prophylaxis with oral vancomycin is highly effective in preventing CDI in alloHCT recipients without increasing the risk of graft-versus-host disease or disease relapse. Further evaluation via a prospective study is warranted.

A Clinical Prediction Tool for Extended-Spectrum Cephalosporin Resistance in Community-Onset Enterobacterales Urinary Tract Infection

Background

Bacterial resistance to first line antibiotics used to treat community-onset urinary tract infections (UTIs) continues to increase. We sought to create a clinical prediction tool for community-onset UTIs due to extended-spectrum cephalosporin-resistant (ESC-R) Enterobacterales (formerly Enterobacteriaceae, EB).

Methods

A case-control study was performed. The source population included patients presenting to an emergency department (ED) or outpatient practice with an EB UTI between 2010 and 2013. Case patients had ESC-R EB UTIs. Control patients had ESC-susceptible EB UTIs and were matched to cases 1:1 on study year. Multivariable conditional logistic regression was performed to develop the predictive model by maximizing the area under the receiver-operating curve (AUC). Internal validation was performed via bootstrapping.

Results

A total of 302 patients with a community-onset EB UTI were included, with 151 cases and 151 controls. After multivariable analysis, we found that presentation with an ESC-R EB community-onset UTI could be predicted by the following: (1) a history of malignancy; (2) a history of diabetes; (3) recent skilled nursing facility or hospital stay; (4) recent trimethoprim-sulfamethoxazole exposure; and (5) pyelonephritis at the time of presentation (AUC 0.73, Hosmer-Lemeshow goodness-of-fit P value 0.23). With this model, each covariate confers a single point, and a patient with ≥ 2 points is considered high risk for ESC-R EB (sensitivity 80%, specificity 54%). The adjusted AUC after bootstrapping was 0.71.

Conclusions

Community-onset ESC-R EB UTI can be predicted using the proposed scoring system, which can help guide diagnostic and therapeutic interventions.

Association of 30-Day Mortality With Oral Step-Down vs Continued Intravenous Therapy in Patients Hospitalized With Enterobacteriaceae Bacteremia

IMPORTANCE

Conversion to oral therapy for Enterobacteriaceae bacteremia has the potential to improve the quality of life of patients by improving mobility, eliminating catheter-associated discomfort, decreasing the risk for noninfectious and infectious catheter-associated adverse events, and decreasing health care costs.

OBJECTIVE

To compare the association of 30-day mortality with early oral step-down therapy vs continued parenteral therapy for the treatment of Enterobacteriaceae bloodstream infections.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective multicenter cohort study included a 1:1 propensity score-matched cohort of 4967 unique patients hospitalized with monomicrobial Enterobacteriaceae bloodstream infection at 3 academic medical centers from January 1, 2008, through December 31, 2014. Eligibility criteria included appropriate source control measures, appropriate clinical response by day 5, active antibiotic therapy from day 1 until discontinuation of therapy, availability of an active oral antibiotic option, and ability to consume other oral medications or feeding. Statistical analysis was performed from March 2, 2018, to June 2, 2018.

EXPOSURES

Oral step-down therapy within the first 5 days of treatment of Enterobacteriaceae bacteremia.

MAIN OUTCOMES AND MEASURES

The main outcome was 30-day all-cause mortality.

RESULTS

Of the 2161 eligible patients, 1185 (54.8%) were male and 1075 (49.7%) were white; the median (interquartile range [IQR]) age was 59 (48-68) years. One-to-one propensity-score matching yielded 1478 patients, with 739 in each study arm. Sources of bacteremia included urine (594 patients [40.2%]), gastrointestinal tract (297 [20.1%]), central line-associated (272 [18.4%]), pulmonary (58 [3.9%]), and skin and soft tissue (41 [2.8%]). There were 97 (13.1%) deaths in the oral step-down group and 99 (13.4%) in the intravenous (IV) group within 30 days (hazard ratio [HR], 1.03; 95% CI, 0.82-1.30). There were no differences in recurrence of bacteremia within 30 days between the groups (IV, 6 [0.8%]; oral, 4 [0.5%]; HR, 0.82 [0.33-2.01]). Patients transitioned to oral step-down therapy were discharged from the hospital an average of 2 days (IQR, 1-6) sooner than patients who continued to receive IV therapy (5 days [IQR, 3-8 days] vs 7 days [IQR, 4-14 days]; P < .001).

CONCLUSIONS AND RELEVANCE

In this study, 30-day mortality was not different among hospitalized patients who received oral step-down vs continued parenteral therapy for the treatment of Enterobacteriaceae bloodstream infections. The findings suggest that transitioning to oral step-down therapy may be an effective treatment approach for patients with Enterobacteriaceae bacteremia who have received source control and demonstrated an appropriate clinical response. Early transition to oral step-down therapy may be associated with a decrease in the duration of hospital stay for patients with Enterobacteriaceae bloodstream infections.

Abstract P3-03-05: Not presented

This abstract was not presented at the conference.

Citation Format: Jung S-Y, Han JH, Park SJ, Lee E-G, Lee MH, Lee ES, Kang H-S, Lee KS, Park IH, Sim SH, Jeong HJ, Kwon Y, Lee D-E, Joo J, Kim S-K, Lee S. Not presented [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 P3-03-05.

The role of extended-spectrum cephalosporin-resistance in recurrent community-onset Enterobacteriaceae urinary tract infections: a retrospective cohort study

Background

Bacterial resistance to first line antibiotics used to treat community-onset urinary tract infections (UTIs) continues to emerge. We sought to determine the association between extended-spectrum cephalosporin resistance (ESC-R) and recurrence among Enterobacteriaceae (EB) UTIs.

Methods

A retrospective cohort study was performed. All patients presenting to the Emergency Departments (EDs) or outpatient practices in a large health system with EB UTIs between 2010 and 2013 were included. Exposed patients had ESC-R EB UTIs. Unexposed patients had ESC-susceptible EB UTIs and were matched to exposed patients 1:1 on study year. Multivariable Cox proportional hazards regression analyses were performed to evaluate the association between ESC-R EB UTI and time to recurrent UTI within 12 months.

Results

A total of 302 patients with an index community-onset EB UTI were included, with 151 exposed and 151 unexposed. Overall, 163 (54%) patients experienced a recurrent UTI with a median time to recurrence of 69 days (interquartile range 25–183). On multivariable analyses, ESC-resistance was associated with an increased hazard of recurrent UTI (hazard ratio [HR] 1.39, 95% confidence interval [CI] 1.01–1.91, P = 0.04). Other variables that were independently associated with recurrence included a history of UTI prior to the index UTI and presence of a urinary catheter at the time of the index UTI. Secondarily, we found that when the treatment for the index UTI was adjusted for, there was no longer a significant association between ESC-R status and time to recurrent UTI (aHR 1.26, 95% CI 0.91–1.76, P = 0.17).

Conclusions

Community-onset UTI due to EB demonstrating ESC-resistance is associated with a significantly increased hazard of recurrent UTI within 12 months compared to ESC-susceptible EB, even after adjusting for baseline factors that predispose patients to UTI recurrence. This association appears to be driven primarily by delayed or inappropriate treatment for the index ESC-R EB UTI.

Inhibition of Cannabinoid Receptor 1 Can Influence the Lipid Metabolism in Mice with Diet-Induced Obesity

A growing number of evidences accumulated about critical metabolic role of cannabinoid type 1 receptor (CB1), carnitine palmitoyltransferase-1 (CPT1) and peroxisome proliferator-activated receptors (PPARs) in some peripheral tissues, including adipose tissue, liver, skeletal muscle and heart. To better understand the interactions of CB1, CPT1 and PPARs in these tissues, 30 diet-induced obese (DIO) C57BL/6J male mice were obtained, weight-matched and divided into two groups (15 in each group): (i) DIO/vehicle mice (D-Veh) and (ii) DIO/SR141716 mice (D-SR) treated with SR141716 (or rimonabant, a selective CB1 receptor blocker) administered orally (10 mg/kg daily). Another 15 mice fed standard diet (STD) formed the STD/vehicle group (S-Veh). At the end of 3-week treatment, mean body weight was 28.4 ± 0.5, 36.5 ± 0.8, and 30.3 ± 1.2 g for the S-Veh, D-Veh, and D-SR group, respectively (p < 0.05; D-Veh vs. D-SR). Liver weight in the D-SR group was also decreased significantly compared to the D-Veh group (p < 0.05). Serum levels of total cholesterol, high-density lipoprotein cholesterol, leptin and adiponectin in the D-SR group were ameliorated compared to the D-Veh group (p < 0.05). Both qRT-PCR and Western blot assay revealed that CB1 expression levels were efficiently blocked by SR141716 in subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), skeletal muscles and liver (D-SR vs. D-Veh; p < 0.05), whereas there was no significant difference between S-Veh and D-Veh mice (p > 0.05). Simultaneously with the reduction of CB1 expression in the D-SR group, the expression levels of CPT1A isoform (protein) in the liver and heart and CPT1B isoform (protein) in the SAT, VAT, liver and skeletal muscles were significantly increased (p < 0.05; D-SR vs. D-Veh). Interestingly, the CPT1A and CPT1B expression levels in heart were detected slightly. The expression levels of PPARα in the SAT, VAT, liver and skeletal muscles and PPARγ in the SAT and skeletal muscles in the D-SR group were significantly increased compared to the D-Veh mice (p < 0.05). However, the PPARβ expression level differed from that of PPARα and PPARγ. Taken together, these data indicate that the inhibition of CB1 could ameliorate lipid metabolism via the stimulation of the CPT1A and CPT1B expression in vivo. Simultaneously, the PPARα and PPARγ expression levels significantly differed compared to that of PPARβ in obesity and lipid metabolism-related disorders under blockade of CB1. Both the mechanism of the influence of CB1 inhibition on lipid metabolism in the examined tissues and the specific mechanism of PPARα, PPARγ and PPARβ involvement in lipid exchange under these conditions remain to be further elucidated.

1595. Impact of Levofloxacin for the Prophylaxis of Bloodstream Infection on the Gut Microbiome in Patients with Hematologic Malignancy

Background

Prophylactic antibiotics for the prevention of bloodstream infections (BSIs) during neutropenia (NTP) may reduce the incidence of BSIs, NTP fever, and mortality. However, antibiotics may also result in dysbiosis of the gut microbiome. We aimed to study the impact of levofloxacin prophylaxis compared with broad-spectrum β-lactam (BSBL) antibiotics used for the treatment of NTP fever on gut microbiome features in patients with hematologic malignancy.

Methods

Stool specimens from hematologic malignancy patients admitted for chemotherapy or stem cell transplant (SCT) in the setting of the evaluation of diarrhea were collected from September 2017 to November 2017. Levofloxacin prophylaxis was standard of care for patients undergoing autologous SCT or induction chemotherapy for acute myeloid leukemia (AML). 16S rRNA (V1–V2 amplicon) sequencing was performed using the Illumina HiSeq platform, formation of operational taxonomic units (OTUs) was performed using QIIME 1.9.1, and taxonomic assignment was performed via the GreenGenes database (13.8). Descriptive statistics were used to compare microbiome features.

Results

A total of 57 samples from 44 patients were included, most with AML (42%), multiple myeloma (33%), or non-Hodgkin’s lymphoma (12%). In the 7 days prior to sample collection, 28 (49%) patients received a BSBL and 17 (29%) received levofloxacin. The gut microbiome of patients with BSBL exposure had significantly reduced Shannon alpha diversity compared with those without: median 1.96 (IQR 1.08–2.57) vs. 2.58 (IQR 2.05–2.93); P < 0.01. However, those with and without levofloxacin exposure showed no difference: median 2.37 (IQR 2.19–2.75) vs. 2.22 (IQR 1.71–2.81), respectively; P = 0.48. Additionally, those with BSBL exposure trended toward increased dominance with non-Bacteroidetes taxa: 14 (60%) vs. 14 (41%); P = 0.14. In contrast, levofloxacin exposure was associated with a lower risk of dominance: 2 (8%) vs. 15 (55%); P < 0.01 and was associated with a greater proportion of Bacteroidetes taxa: 75% vs. 27% (P < 0.01).

Conclusion

Our findings suggest that the impact of antibiotics on the gut microbiome vary by class, and that levofloxacin may have limited impact on the gut microbiome in this patient population. Further studies are needed to investigate this potential differential impact of antibiotic classes.

Disclosures

D. Pegues, DaVita / Total Renal Care: Consultant, Consulting fee.

Fluoroquinolone Prophylaxis Is Highly Effective for the Prevention of Central Line-Associated Bloodstream Infections in Autologous Stem Cell Transplant Patients

Patients undergoing stem cell transplant (SCT) for the treatment of hematologic malignancy are at increased risk for central line-associated bloodstream infections (CLABSIs). The use of prophylactic antibiotics to prevent CLABSIs in the setting of autologous SCT is of unclear benefit. We aimed to evaluate the impact of levofloxacin prophylaxis on reducing CLABSIs in this high-risk population. Patients undergoing autologous SCT at a tertiary care hospital received levofloxacin prophylaxis from January 13, 2016 to January 12, 2017. Levofloxacin was administered from autologous SCT (day 0) until day 13, absolute neutrophil count > 500/mm³, or neutropenic fever, whichever occurred first. Clinical outcomes were compared with a baseline group who underwent autologous SCT but did not receive antibacterial prophylaxis during the previous year. The primary endpoint was incidence of CLABSIs assessed using Cox proportional hazards regression. A total of 324 patients underwent autologous SCT during the entire study period, with 150 receiving levofloxacin prophylaxis during the intervention period. The rate of CLABSIs was reduced from 18.4% during the baseline period to 6.0% during the intervention period. On multivariable analysis levofloxacin prophylaxis significantly reduced CLABSI incidence (hazard ratio, .33; 95% confidence interval [CI], .16 to .69; P = .003). There was also a reduction in the risk of neutropenic fever (odds ratio [OR], .23; 95% CI, .14 to .39; P < .001) and a trend toward a reduction in intensive care unit transfer for sepsis (OR, .33; 95% CI, .09 to 1.24; P = .10) in patients receiving levofloxacin prophylaxis. Notably, there was no increase in Clostridium difficile infection in the levofloxacin group (OR, .66; 95% CI, .29 to 1.49; P = .32). Levofloxacin prophylaxis was effective in reducing CLABSIs and neutropenic fever in patients undergoing autologous SCT. Further studies are needed to identify specific patient groups who will benefit most from antibiotic prophylaxis.

Implementation of a Pragmatic Biomarker-Driven Algorithm to Guide Antibiotic Use in the Pediatric Intensive Care Unit: the Optimizing Antibiotic Strategies in Sepsis (OASIS) II Study

BACKGROUND

Biomarkers can facilitate safe antibiotic discontinuation in critically ill patients without bacterial infection.

METHODS

We tested the ability of a biomarker-based algorithm to reduce excess antibiotic administration in patients with systemic inflammatory response syndrome (SIRS) without bacterial infections (uninfected) in our pediatric intensive care unit (PICU). The algorithm suggested that PICU clinicians stop antibiotics if (1) C-reactive protein <4 mg/dL and procalcitonin <1 ng/mL at SIRS onset and (2) no evidence of bacterial infection by exam/testing by 48 hours. We evaluated excess broad-spectrum antibiotic use, defined as administration on days 3-9 after SIRS onset in uninfected children. Incidence rate ratios (IRRs) compared unadjusted excess length of therapy (LOT) in the 34 months before (Period 1) and 12 months after (Period 2) implementation of this algorithm, stratified by biomarker values. Segmented linear regression evaluated excess LOT among all uninfected episodes over time and between the periods.

RESULTS

We identified 457 eligible SIRS episodes without bacterial infection, 333 in Period 1 and 124 in Period 2. When both biomarkers were below the algorithm's cut-points (n = 48 Period 1, n = 31 Period 2), unadjusted excess LOT was lower in Period 2 (IRR, 0.53; 95% confidence interval, 0.30-0.93). Among all 457 uninfected episodes, there were no significant differences in LOT (coefficient 0.9, P = .99) between the periods on segmented regression.

CONCLUSIONS

Implementation of a biomarker-based algorithm did not decrease overall antibiotic exposure among all uninfected patients in our PICU, although exposures were reduced in the subset of SIRS episodes where biomarkers were low.

Increased 30-Day Mortality Associated With Carbapenem-Resistant Enterobacteriaceae in Children

In this multicenter study, we identified an increased risk of 30-day mortality among hospitalized children with carbapenem-resistant Enterobacteriaceae (CRE) isolated from clinical cultures compared with those with carbapenem-susceptible Enterobacteriaceae. We additionally report significant variation in antibiotic treatment for children with CRE infections with infrequent use of combination therapy.

Can the Ceftriaxone Breakpoints Be Increased Without Compromising Patient Outcomes?

Background

In 2010, the Clinical Laboratory and Standards Institute recommended a 3-fold lowering of ceftriaxone breakpoints to 1 mcg/mL for Enterobacteriaceae. Supportive clinical data at the time were from fewer than 50 patients. We compared the clinical outcomes of adults with Enterobacteriaceae bloodstream infections treated with ceftriaxone compared with matched patients (with exact matching on ceftriaxone minimum inhibitory concentrations [MICs]) treated with extended-spectrum agents to determine if ceftriaxone breakpoints could be increased without negatively impacting patient outcomes.

Methods

A retrospective cohort study was conducted at 3 large academic medical centers and included patients with Enterobacteriaceae bacteremia with ceftriaxone MICs of 2 mcg/mL treated with ceftriaxone or extended-spectrum β-lactams (ie, cefepime, piperacillin/tazobactam, meropenem, or imipenem/cilastatin) between 2008 and 2014; 1:2 nearest neighbor propensity score matching was performed to estimate the odds of recurrent bacteremia and mortality within 30 days.

Results

Propensity score matching yielded 108 patients in the ceftriaxone group and 216 patients in the extended-spectrum β-lactam group, with both groups well-balanced on demographics, preexisting medical conditions, severity of illness, source of bacteremia, and source control interventions. No difference in recurrent bacteremia (odds ratio [OR], 1.16; 95% confidence interval [CI], 0.49–2.73) or mortality (OR, 1.27; 95% CI, 0.56–2.91) between the treatment groups was observed for patients with isolates with ceftriaxone MICs of 2 mcg/mL. Only 6 isolates (1.6%) with ceftriaxone MICs of 2 mcg/mL were extended-spectrum β-lactamase (ESBL)–producing.

Conclusions

Our findings suggest that patient outcomes are similar when receiving ceftriaxone vs extended-spectrum agents for the treatment of Enterobacteriaceae bloodstream infections with ceftriaxone MICs of 2 mcg/mL. This warrants consideration of adjusting the ceftriaxone susceptibility breakpoint from 1 to 2 mcg/mL, as a relatively small increase in the antibiotic breakpoint could have the potential to limit the use of large numbers of extended-spectrum antibiotic agents.

Using Patient Risk Factors to Identify Whether Carbapenem-Resistant Enterobacteriaceae Infections Are Caused by Carbapenemase-Producing Organisms

Evaluating all inpatient carbapenem-resistant Enterobacteriaceae (CRE) infections over a 1-year period, 47% were caused by carbapenemase-producing (CP) organisms. Compared with non-CP-CRE patients, patients with CP-CRE had an 18-fold greater odds of a recent stay in a foreign health care facility and a 3-fold greater odds of transfer from a post–acute care facility.

Abstract P4-06-12: Different patterns of risk reducing decisions in affected or unaffected BRCA mutation carriers

BACKGROUND

Risk-reducing (RR) management decreases the risk of breast cancer and BRCA related gynecologic cancer. However, there are fewer reports on the RR management in Asia compared to Western countries.The aim of this study is to identify risk reducing management patterns with BRCA1 or BRCA2 mutation carriers.

METHODS

The study group consisted of all consecutive 1104 breast cancer, ovarian patients and their families of high-risk patients who underwent BRCA gene testing in National Cancer Center, Korea from 2008 to 2016. A total 220 BRCA mutations (19.9%) were detected with 125(11.3%) of BRCA1 gene and 95 (8.6%) of BRCA2 gene.

RESULTS

Out of 220 BRCA mutations carriers, they were consisted of 83 breast cancers, 10 ovarian cancers, 7 both cancers, and 120 unaffected carriers. Among them, 42 were men and 178 were women. About 90 % (198/ 220) had the familial history of breast, ovarian or both malignancies (113 in BRCA1 and 85 in BRCA2 mutation (p=0.821)).

All 42 men chose surveillance. Among 178 female BRCA mutation carriers, 98(55.1%) underwent risk reducing management including 18(10.1%) of chemoprevention, and 80(49.9%) had risk-reducing surgeries (RRSs) (1 case of risk-reducing mastectomy, 76 of risk reducing bilateral salphingo-oophorectomy (RRSO), and 3 of both) and 80 (54.9%) chose only intensive surveillance for both of breast and ovary cancer.

In affected carriers with breast cancer, 59 (71.1%) underwent RR management (1 case of risk reducing mastectomy, 53 of RRSO, 3 of both surgery, and 2 of chemoprevention). There was no risk reducing management in affected carrier with ovarian cancer patients. In 78 unaffected women carriers, 39(50.0%) women received RR management (23(29.5%) cases of RRSO and 16(20.5%) cases of chemoprevention). The rates of RRSs have increased annually since the 2013 year, (prior to 2013 vs. since 2013, RRSs 28.6% (6 cases/21 carriers) vs. 37.2% (74/199), p&lt;0.01).

CONCLUSION

This study was conducted on the largest numbers of BRCA mutation carriers in Asian countries. RRSO is the more preferred management for affected carriers with breast cancer or unaffected carriers. The results might be explained by the severity of the illness and that RRSO was only reimbursed RR strategy from the Korean Government Insurance. Tailored genetic counseling and insurance policy may enhance overall levels of RR management.

Citation Format: Lee EG, Kang H, Park SJ, Han JH, Jung S-Y, Lee S, Kang H-S, Park B, Kong S-Y, Lim MC, Park S-Y, Lee ES. Different patterns of risk reducing decisions in affected or unaffected BRCA mutation carriers [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-06-12.

[Analysis of curative effect of transoral radiofrequency ablation microsurgery on glottic carcinoma with anterior commissure involvement at the early stage]

Objective: To explore the key technique and outcome of transoral radiofrequency ablation microsurgery for early stage of glottic carcinoma with anterior commissure involvement (ACI). Methods: A retrospective analysis was conducted on 31 patients, who were diagnosed as early stage glottic carcinoma during January 2010 to March 2016 in ENT Department. According to whether the anterior commissure was involved or not, two groups were divided. There were eleven cases with ACI (stages T1a, T1b, and T2). Twenty cases without ACI (stages Tis, T1a, and T2). All the patients received transoral radiofrequency ablation microsurgery and followed up closely.Only one case received radiotheraphy after surgery. SPSS19.0 software was used to analyze data. Results: The follow-up time was 12-67 months, and the median follow-up time was 30 months. Nine among 11 cases with ACI obtained good oncologic outcomes, initial local recurrence was identified in 2/11 cases, including 2 cases of T2. Two cases ultimately required salvage total laryngectomy. Meanwhile, initial local recurrence was identified in 2/20 cases without ACI, including 1 case of T1a and 1 case of T2. One case underwent elective neck dissection, and another one received salvage total laryngectomy.Compared to the patients without ACI, it seemed that the cases with ACI always accomponied with a little higher initial local recurrence and lower overall laryngealpreservation, but the difference had no significance (P>0.05). Conclusions: Transoral radiofrequency ablation microsurgery is an effective treatment for glottic carcinoma with ACI. Its advantages, such as more flexibility and deformability, make it more feasible to operate at the narrow space of anterior commissure assisted with laryngeal endoscopy.Good oncologic outcomes can be obtained by this technique with lower initial local recurrence as well as higher overall laryngeal preservation rate.

Dynamic re-immunization of off-treatment childhood cancer survivors: An implementation feasibility study

There are no universally approved re-vaccination guidelines for non-transplant pediatric cancer survivors. We hypothesized that by utilizing a response-based re-vaccination schedule, we could tailor vaccine schedules in off-treatment cancer survivors. Pre-vaccination antibody levels were obtained in 7 patients at an average of 20 days after the end of treatment date. In those without protective antibody levels, we administered vaccines 3 months after completion of treatment. Revaccinating patients 3 months after the end of treatment date resulted in protective antibody levels for most vaccines. We showed, on a preliminary basis, that vaccinating non-transplanted pediatric cancer survivors can be dynamically implemented in children with recovering immune function.

Comparing the Outcomes of Adults With Enterobacteriaceae Bacteremia Receiving Short-Course Versus Prolonged-Course Antibiotic Therapy in a Multicenter, Propensity Score-Matched Cohort

Background

The recommended duration of antibiotic treatment for Enterobacteriaceae bloodstream infections is 7-14 days. We compared the outcomes of patients receiving short-course (6-10 days) vs prolonged-course (11-16 days) antibiotic therapy for Enterobacteriaceae bacteremia.

Methods

A retrospective cohort study was conducted at 3 medical centers and included patients with monomicrobial Enterobacteriaceae bacteremia treated with in vitro active therapy in the range of 6-16 days between 2008 and 2014. 1:1 nearest neighbor propensity score matching without replacement was performed prior to regression analysis to estimate the risk of all-cause mortality within 30 days after the end of antibiotic treatment comparing patients in the 2 treatment groups. Secondary outcomes included recurrent bloodstream infections, Clostridium difficile infections (CDI), and the emergence of multidrug-resistant gram-negative (MDRGN) bacteria, all within 30 days after the end of antibiotic therapy.

Results

There were 385 well-balanced matched pairs. The median duration of therapy in the short-course group and prolonged-course group was 8 days (interquartile range [IQR], 7-9 days) and 15 days (IQR, 13-15 days), respectively. No difference in mortality between the treatment groups was observed (adjusted hazard ratio [aHR], 1.00; 95% confidence interval [CI], .62-1.63). The odds of recurrent bloodstream infections and CDI were also similar. There was a trend toward a protective effect of short-course antibiotic therapy on the emergence of MDRGN bacteria (odds ratio, 0.59; 95% CI, .32-1.09; P = .09).

Conclusions

Short courses of antibiotic therapy yield similar clinical outcomes as prolonged courses of antibiotic therapy for Enterobacteriaceae bacteremia, and may protect against subsequent MDRGN bacteria.

Epidemiology of Carbapenem-Resistant Klebsiella pneumoniae in a Network of Long-Term Acute Care Hospitals

Background

The rapid emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) represents a major public health threat, including in the long-term acute care hospital (LTACH) setting. Our objective in this study was to describe the epidemiologic characteristics of CRKP in a network of US LTACHs.

Methods

An observational study was performed among 64 LTACHs from January 2014 to March 2015. Clinical cultures were included, with the first CRKP isolate recovered from each patient per study quarter evaluated. LTACH and geographic area-based CRKP prevalence and clinical and microbiologic characteristics were described.

Results

A total of 3846 K. pneumoniae cultures were identified, with an overall carbapenem resistance rate of 24.6%. There were significant differences in CRKP rates across geographic regions, with the highest in the West (42.2%). Of 946 CRKP isolates, 507 (53.6%) were from a respiratory source, 350 (37.0%) from a urinary source, and 9 (9.4%) from blood. Among 821 unique patients with CRKP colonization or infection, the median age was 73 years. There was a high prevalence of respiratory failure (39.8%) and the presence of a central venous catheter (50.9%) or tracheostomy (64.8%). Resistance rates of CRKP isolates were high for amikacin (59.2%) and fluoroquinolones (>97%). The resistance rate to colistin/polymyxin B was 16.1%.

Conclusions

Nearly 25% of K. pneumoniae clinical isolates in a US network of LTACHs were CRKP. Expansion of national surveillance efforts and improved communication among LTACHs and acute care hospitals will be critical for reducing the continued emergence of CRKP across the healthcare continuum.

The Role of Stewardship in Addressing Antibacterial Resistance: Stewardship and Infection Control Committee of the Antibacterial Resistance Leadership Group

Antibacterial resistance is increasing globally and has been recognized as a major public health threat. Antibacterial stewardship is the coordinated effort to improve the appropriate use of antibiotics with the aim to decrease selective pressure for multidrug-resistant organisms in order to preserve the utility of antibacterial agents. This article describes the activities of the Antibacterial Resistance Leadership Group (ARLG) in the area of antibacterial stewardship. To date, the ARLG has focused intensely on development of rapid diagnostic tests, which (when coupled with educational and institutional initiatives) will enable the robust stewardship that is needed to address the current crisis of antibacterial resistance. In addition to exploring the effectiveness of stewardship techniques in community hospitals, the ARLG has also developed strategy trials to assess the feasibility of reducing antibacterial usage while preserving patient outcome.

[Complications analysis of adenoidectomy and tonsillectomy assisted with ablation on children]

Objective:To analyze the complications of adenotonsilectomy assisted with coblation in children. Method:Complications of 2 089 cases of children with adenoid and tonsil surgery assisted with coblation, in our hospital nearly 10 years, were analyzed by epidemiological methods through the method of retrospective analysis. Result:①the sex ratio of male to female was 2.08：1, average age (5.87±3.12) years old, and most of 2 089 cases 76.35% (1 595/2 089) were 3-7 years old; ②all cases underwent adenoidectomy. Different surgery methods of tonsil consisted of three groups as partial resection associated with ablation was 69.17% (1 445/2 089), ablation (channeling) alone was 22.26% (465/2 089) and total resection was 8.57% (179/208). The amount of bleeding in operation was (8.52±3.18)ml, average operation time was (30.15±8.26) minutes, the postoperative pain score was (3.77±1.61); ③The incidence of postoperative complications: postoperative bleeding (all were secondary bleeding cases) rate was 0.24% (5/2 089), recurrence rate was 0.14% (3/2 089), prevertebral lymphadenitis was 0.96% (20/2 089), the other was 0.29% (torus hyperplasia in 2 cases, dyspnea in 2 cases, 1 cases of angle of mouth burned, nasopharyngeal adhesion in 1 cases). Postoperative fever rate was 9.81% (205/2 089). Conclusion:coblation technique is a good method for the treatment of children's adenoids and tonsil diseases with high efficiency and low complications. But improving the operation procedure proficiency level and skills of operation is an important link to reduce complications.

Comparing the Outcomes of Adults with Enterobacteriaceae Bacteremia Receiving Short-Course vs Prolonged-Course Antibiotic Therapy

Background

The recommended duration of antibiotic treatment for Enterobacteriaceae bacteremia is between 7 and 14 days. We compared the clinical outcomes of patients receiving short-course (6–10 days) vs prolonged-course (11–15 days) antibiotic therapy for Enterobacteriaceae bacteremia.

Methods

A retrospective cohort study was conducted at The Johns Hopkins Hospital, The University of Maryland Medical Center, and The Hospital of the University of Pennsylvania including patients with monomicrobial Enterobacteriaceae bacteremia treated with in vitro active antibiotic therapy in the range of 6–15 days between 2008 and 2014. 1:1 nearest neighbor propensity score matching without replacement was performed, prior to regression analysis, to estimate the risk of all-cause mortality within 30 days after the end of antibiotic treatment for patients receiving short vs. prolonged durations of antibiotic therapy. Secondary outcomes included Clostridium difficile infection (CDI) and the emergence of multidrug-resistant Gram-negative (MDRGN) bacteria within 30 days after the end of antibiotic therapy.

Results

A total of 1,769 patients met eligibility criteria. There were 385 matched pairs who were well-balanced on baseline characteristics. The median duration of therapy in the short-course group and prolonged-course group was 8 days (interquartile range (IQR) 7–9 days) and 15 days (IQR 13–15 days), respectively. No difference in all-cause mortality between short- and prolonged-course treatment groups was observed (adjusted hazard ratio [aHR] 1.00; 95% CI 0.62–1.63). Rates of CDI were similar between the treatment groups (OR 1.17; 95% CI 0.39–3.51). There was a non-significant protective effect of short-course antibiotic therapy on the emergence of MDRGN bacteria (OR 0.59; 95% CI 0.32–1.09 P = 0.09).

Conclusion

Short courses of antibiotic therapy yields similar clinical outcomes to prolonged courses of antibiotic therapy for Enterobacteriaceae bacteremia, and may protect against subsequent MDRGN emergence.

Disclosures

All authors: No reported disclosures.

[The images of osteoarthrosis associated with anterior disc displacement without reduction detected by cone-beam CT]

Objective: To analyze the radiological characteristics of the condylar bone in patients with anterior disc displacement without reduction of temporomandibular joint using cone-beam CT (CBCT), and to further investigate the clinical factors possibly associated with the early-stage osteoarthritic changes. Methods: Two hundred and four individuals (≤30 years old) diagnosed as unilateral anterior disc displacement without reduction (disease duration≤1 year) were recruited. CBCT images of bilateral condyles were independently evaluated by two assessors and documented. Correlation between the early-stage osteoarthritic (OA) changes and gender, age, disease duration and mouth opening were analyzed using SPSS 21.0 software. Results: About sixty percent were presented with OA changes in the symptomatic joints, and most of them (47.1%) (96/204) were early-stage OA changes characterized by loss of continuity of articular cortex (Ⅰ) and/or surface erosion (Ⅱ). Logistics regression analyses indicated that disease duration (P =0.000) and mouth opening (P =0.002) were correlated significantly with early-stage OA changes. Conclusions: Disc displacement without reduction was closely related to OA occurrence. OA changes occurred in more than half of the patients after one month of the joint locked and more possibly in patients with increased mouth opening.