bluuebunny/crossref_metadata_2025_split huggingface dataset:
#76: Epidemiology of Cytomegalovirus (CMV) in Pediatric Solid-Organ Transplant Recipients (SOTR) at Texas Children’s Hospital (TCH)
Authors: Valencia Deray K , Hosek K , Moulton E , Munoz F , Demmler-Harrison G , Bocchini C 
Published: March 2021

Abstract

Background
Despite the widespread use of prevention strategies, CMV remains a common opportunistic infection in SOTR. Contemporary data regarding CMV in pediatric SOTR are limited. We sought to determine the frequency of and risk factors for CMV infection and disease in a large single-center cohort of pediatric SOTR.

Methods
A retrospective cohort study of patients &lt;22 years of age who received lung, heart, liver, kidney, or multi-organ transplants at TCH between 2010 and 2018 was completed. Universal CMV prophylaxis was used based on risk status (Figure 1). The primary outcome was quantifiable CMV DNAemia. Associations with CMV DNAemia were measured using Fisher exact, Kruskal–Wallis, and multivariate logistic regression. Survival analysis and time to CMV infection were assessed using Kaplan–Meier plots.

Results
Among 788 SOTR, 132 (17%) had quantifiable CMV DNAemia; this included 20/105 (19%) lung, 69/290 (24%) liver, 28/178 (16%) heart, 2/15 (13%) multi-organ, and 13/200 (7%) kidney recipients. Fifty-one (6%) SOTR had CMV DNAemia while on antiviral prophylaxis. Post-prophylaxis, 69 (9%) SOTR had CMV reactivation and 12 (2%) had primary infection. The median time to quantifiable DNAemia for patients that developed CMV was 290 days post-transplant for lung, 162 for liver, 186 for heart, and 294 for kidney (P &lt; 0.01), reflecting differences in prophylaxis strategies. High-risk CMV status (D+/R– for heart, liver, kidney, and D+ and/or R+ for lung) was associated with CMV DNAemia (P &lt; 0.01). Type of organ transplanted also showed an association with CMV DNAemia (P = 0.02) with liver transplant recipients more being more likely to have a positive CMV PCR. DNAemia was not associated with age at transplantation, type of organ, or the use of induction immunosuppression. There was no difference in survival during the study follow-up period (1–9 yr) for SOTR with vs. without DNAemia (P = 0.48). Overall, 22/788 (3%) SOTR had CMV disease, 3 (3%) lung, 4 (2%) heart, 8 (3%) liver, 1 (6%) multi-organ, and 6 (3%) kidney recipients. Twenty had CMV syndrome and 2 had tissue invasive disease. Median (range) maximum viral loads were 27700 IU/mL (233-3912694) for SOTR with vs. 900 IU/mL (26-112000) for SOTR without CMV disease (P &lt; 0.01).

Conclusion
This large contemporary cohort of pediatric SOTR on universal prophylaxis demonstrates low overall rates of CMV DNAemia and CMV disease. High-risk CMV status remains associated with CMV DNAemia, suggesting that further interventions targeting this group may be warranted.
#65: Characterization of Resistance Patterns Among Isolates of E. coli and Klebsiella sp. from Wastewater, and Clinical Samples in a Tertiary Care Children’s Hospital in Lima, Peru
Authors: Santillán Carlos F , Tsukayama Pablo , Calderón Maritza , Castillo Camila , Huancachoque Janet 
Published: March 2021

Abstract

Background
Environmental monitoring of enterobacteria in hospital wastewater could be a useful tool to understand the composition of the microbiota in patients, their visits, and healthcare personnel, but it also may be useful for monitoring antimicrobial resistance among healthcare-associated infections in hospitalized patients. The aim of this study was to characterize and describe the phenotypic and genotypic antimicrobial resistance of Escherichia coli and Klebsiella sp. strains from wastewater and from clinical isolates in a tertiary care children’s hospital in Lima, Perú.

Methods
We systematically collected 70 isolates of Escherichia coli and Klebsiella sp. from wastewater and 24 isolates of the same enterobacteria from blood and urine cultures at Instituto Nacional de Salud del Niño San Borja (INSN-SB) in Lima from December 2018 to May 2019. Susceptibility profiles were evaluated following CLSI criteria. We used the Jarlier method for the detection of extended-spectrum beta-lactamases (ESBL). For detection of AmpC beta-lactamases, we used discs of cefoxitin, ceftazidime, and ceftriaxone combined with cloxacillin and cefotaxime. For the detection of carbapenemase production, we used EDTA and phenylboronic acid inhibitors between meropenem and imipenem disks. We performed genomic sequencing for the detection of resistance genes and to perform a phylogenetic cluster analysis.

Results
We collected a total of 94 isolates (70 from wastewater and 24 from clinical samples). Among the total isolates, 19 (20.2%) were ESBL producers. The frequency of ESBL producers in wastewater was 7.1% (5/24), whereas the frequency of ESBL producers in clinical samples was 58.3% (14/70). The most frequent resistance genes were tet (variant 34 and A) and blaTEM-1. The frequency of tet(34) and tet(A) were 10% and 7%, respectively, in isolates from wastewater, whereas the frequency of these genes were 0% and 6%, respectively, in clinical isolates. The gene blaCTX-M-15 was present in isolates from wastewater (1%) and clinical samples (2%). Phylogenetic cluster analysis found no similarities between isolates from wastewater and to those from clinical samples, suggesting that the population of these enterobacteria were different in wastewater compared with clinical samples.

Conclusions
Enterobacteria from hospital wastewater may not reflect the profile of infections caused by these microorganisms. However, they may reflect the microbiological microbiota among patients, their visits, and hospital healthcare personnel. Further studies that compare the phenotypic and genotypic characteristics among isolates from wastewater and the enteric microbiota from these individuals would be necessary to assess this hypothesis.
#61: Antibiotic Use for Community-Acquired Pneumonia Among Hospitalized Children in Japan
Authors: Tao-Kidoguchi Chiaki , Ogawa Eiki , Shoji Kensuke , Miyairi Isao 
Published: March 2021

Abstract

Background
Judicious use of antimicrobials is the cornerstone of action against antimicrobial resistance. Respiratory tract infections account for over 80% of pediatric antibiotic use in Japan. Antibiotics are generally used empirically for most hospitalized patients with pneumonia although it is becoming clearer that viral etiologies account for approximately 70% of these cases. Defining the characteristics of patients who are managed with a short course of antibiotics and subsequently do well, may lead to setting clinical criteria for early termination of antibiotics.

Methods
We performed a retrospective descriptive analysis. Medical charts of patients aged 3 months to 18 years, who were admitted with a diagnosis of pneumonia, bronchitis, bronchiolitis, or asthma to the Department of Interdisciplinary medicine at the National Center for Child Health and Development from March 2018 through February 2019 were reviewed. Those who had respiratory symptoms and were started on antibiotics within 48 hours of hospitalization were included. Those who had a focus of infection elsewhere or were immunocompromised were excluded.

Results
Of the 556 candidates, 80 patients met the criteria. The median age was 1.5 years which included 42.5% (34/80) with comorbidities. Underlying conditions included 9 with trisomy 21, and 8 with perinatal issues. Rapid antigen testing was performed and 7 patients with RSV, 5 patients with influenza, 1 patient with human metapneumovirus were identified. The average duration of antibiotic therapy was 7.2 days (range 2–14 days). There were no statistical differences in the characteristics of patients who received antibiotics for more or less than 5 days. The positivity of the rapid antigen test tended to be higher in those who received antibiotics for a shorter period (25% vs. 15%). There were no differences in the rate of readmission or complications between the two groups.

Conclusion
We were unable to identify a clear characteristic of patients who received short courses of antibiotics for pneumonia. The trend observed for those who had a point of care testing may suggest that the use of a multiplex PCR testing covering a greater number of pathogens would influence physician behavior in antibiotic use.
#37: Clinical Characterization of the Cases Relating to the Outbreak of Clostridioides difficile, in a Third-level Hospital in Mexico City: Diagnosis, Treatment, and Relay
Authors: Samuel Ortiz , Elena Martínez María , Ramírez A Morayta 
Published: March 2021

Abstract

Background
Clostridioides difficile is an important cause of healthcare-associated infections. The epidemiology of C. difficile infection (CDI) in children has changed over the past few decades. There is now a higher incidence in hospitalized children, and there has been an emergence of community-onset infection. Neonates and young infants have high rates of colonization but rarely have symptoms. The well-known risk factor for CDI in children age 2 years or older is antibiotic use. Inflammatory bowel disease and cancer are associated with increased incidence and severity of CDI. Vancomycin or fidaxomicin is recommended for an initial episode of CDI. In environments where access to Vancomycin or Fidaxomycin is limited, it is suggested to use metronidazole for an initial episode of nonsevere CDI only.

Methods
A series of cases were carried out, in a study period from March to May 2018, total cases 8; the age group, sex, basic diagnosis, clinical findings, diagnostic method, and outcome in hospitalized patients in the Pediatric division of the “CMN 20 de Noviembre, ISSSTE” were described, where there is a total of 377 Sensitive beds, and 53 beds in the pediatric area of which 30 are not sensitive.

Results
We analyzed 8 cases of diarrhea with identification of C. difficile, in a period of 3 months, where there was a total of 148 admissions to the division of Pediatrics (100%) and presented a prevalence of 0.05% of the total income. Of those 8 cases reported, 37.5% were women and 62.5% men; The age fluctuated between 6 months and 18 years. All children had associated comorbidities. The frequency and type of comorbidities were Cancer 87.5% (Leukemias and Solid Tumors) and Neurological 12.5% ​​(Arterial Malformation and Neurological Sequelae). The main symptom that occurred was mucous diarrhea in 100% of patients, abdominal pain in 25% and evacuation with blood in 12.5% ​​of cases. All had a history of prior treatment with 100% broad-spectrum antibiotics, in a period of less than one month. All were treated with metronidazole (100%) and all presented clinical improvement, without complications; Similarly, all were diagnosed by PCR for toxin B (100%). The attributable risk of presenting Clostridioides disease in patients with Leukemia is 0.11.

Conclusions
Patients with Leukemia were the most affected during the C. difficile outbreak, of which 11 out of 100 of these patients are at risk of presenting C. difficile disease. The most important thing in these cases is prevention. Therefore, specific prevention measures were implemented to reduce the possibility of future outbreaks, such as handwashing with chlorexidine, contact isolation, handwashing every time there is contact with the patient, use of gloves when performing procedures, insulation of bedding in plastic bags and training of health personnel.
#49: Results of 10 Years of Peripherally Inserted Central Catheter Use and the Association with Infections in Pediatric Patients at a Tertiary Care Oncology Hospital
Authors: Acebo Jennia J , Costta María , Sánchez Gisella , Villanueva Erika , Montalvo E Erika , Sánchez Ivonne , Escobar Lizeth , Caniza Miguela 
Published: March 2021

Abstract

Introduction
Pediatric cancer patients merit the placement of central lines for the treatments they receive. Subcutaneous central ports (SCs) and peripherally inserted central catheters (PICCs) are the most frequently used lines. PICCs have gained popularity due to the ease of insertion, which can be invaluable in the pediatric oncology setting for administration of intravenous therapy, parenteral nutrition, and/or blood products. Since central-line-associated bloodstream infections increase the morbidity and mortality of cancer patients, as well as increase the cost generated by their treatment, active surveillance of these healthcare-associated infections is warranted.

Methods
This is a retrospective descriptive study of pediatric patients treated via PICCs at the Hospital SOLCA Núcleo Quito between 2009 and 2019.

Results
During the study period, 70 PICC lines were placed in 66 patients, totaling 1862 catheter-days. The majority of patients (75.7%) were diagnosed with leukemia or lymphoma. As of 2011, all PICCs were placed in the operating room by a surgeon. Ultrasound was used 39 times for the insertion of PICCs. Inadequate peripheral venous access was the most common indication (64.2%) for placement. Twenty-nine PICCs had complications, of which 13 were infectious complications and 16 were noninfectious. The most common infectious complication was PICC-related bloodstream infection (13), and the most frequent noninfectious complication was occlusion (10). The overall complication rate was 15.5 complications per 1000 catheter-days, and the overall infectious complication rate was 6.9 complications per 1000 catheter days. Annual complication rates fluctuated over the study period. The PICC line-associated infection rate per 1000 catheter-days was 13.1‰ in 2009, 12.4‰ in 2010, 5.0‰ in 2011, 7.9‰ in 2012, 0 in 2013, 13.4‰ in 2014, 4.8‰ in 2015, 16.2‰ in 2016, 8.2‰ in 2017, and 4.3‰ in 2018.

Conclusion
In general, complications related to PICC in pediatric patients at a tertiary care oncology hospital have fluctuated over the years. Our findings indicate the need for further efforts in staff education and training in the insertion, care, and maintenance of PICC lines. Best practice guidelines are also critical to reducing complications, especially occlusion and infection rates, to thereby improve patient outcomes.
#70: Comparing Prospectively Identified Etiologic Agents of Neonatal Sepsis in Southwest Ethiopia with WHO Empiric Antibiotic Guidelines
Authors: Gusland Daniele , Berhane Melkamu , Bekele Abinet , Woldegiorgis Yamrot , Siraj Dawd , Conway James 
Published: March 2021

Abstract

Background
Neonatal sepsis accounts for one third of global neonatal mortality. To improve access to treatment for neonatal sepsis, in 2015 the World Health Organization (WHO) released guidance for outpatient treatment (when referral is not possible or refused) of Possible Serious Bacterial Infection (PSBI).1 However, studies from low and middle-income countries suggest that bacteria causing neonatal infection differ from high-income countries, with higher rates of Staphylococcus aureus, Escherichia coli, and Klebsiella species and high rates of antimicrobial resistance. For this reason, local surveillance is vital to develop local antibiograms and tailor appropriate prescribing.

Methods
This is an analysis of the first 6 months of a prospective study of young infants admitted to Jimma University Hospital with PSBI. Young infants admitted to Jimma University Hospital with PSBI (defined by WHO danger signs: poor feeding, seizures, fever, lethargy, hypothermia, tachypnea, and increased work of breathing) are being recruited over a 12-month period. Blood cultures are obtained on admission, incubated in the BACTEC system and positive cultures evaluated for antibiotic susceptibility by Kirby-Bauer Disc diffusion. Primary outcomes are culture positivity, organism identification, and rates of antimicrobial resistance. Secondary outcomes include mortality rates and duration of hospital stay. The data included in this analysis were collected from March 21, 2019, through September 20, 2019. Data collection is ongoing.

Results
In total, 196 infants have been enrolled with a culture positivity rate of 58%. At this time, most frequently identified organisms are Klebsiella spp. (43.4%) and Staphylococcus aureus (12.2%). Gram-negative rods represent 67.8% of the isolates and gram-positive cocci 32.2%. Less than half the isolates (44.4%) were susceptible to either first-line antibiotic (ampicillin and gentamicin). Only 17.4% of the gram-positive cocci were sensitive to oxacillin. In-hospital mortality rates for those with positive cultures approached 15% (compared with 5% for culture negative). The average hospital stay for infants with positive cultures was 13.9 days compared with 10.1 for those with negative cultures.

Conclusion
Klebsiella spp. are responsible for a plurality of neonatal sepsis admissions at Jimma University Hospital. The organisms responsible for neonatal sepsis in southwest Ethiopia are highly resistant to the WHO recommended first-line antibiotics. It is possible that adoption of the WHO guidelines may be inappropriate in this population, which could be better served by tailoring empiric antibiotics to the identified organisms.

Reference
1. World Health Organization. Guideline: Managing possible serious bacterial infection in young infants when a referral is not feasible. (2015) Geneva, CH.
Cell wall thickness and composition are involved in photosynthetic limitation
Authors: Flexas Jaume , Clemente-Moreno María J , Bota Josefina , Brodribb Tim J , Gago Jorge , Mizokami Yusuke , Nadal Miquel , Perera-Castro Alicia V , Roig-Oliver Margalida , Sugiura Daisuke , Xiong Dongliang , Carriquí Marc 
Published: March 2021

AbstractThe key role of cell walls in setting mesophyll conductance to CO2 (gm) and, consequently, photosynthesis is reviewed. First, the theoretical properties of cell walls that can affect gm are presented. Then, we focus on cell wall thickness (Tcw) reviewing empirical evidence showing that Tcw varies strongly among species and phylogenetic groups in a way that correlates with gm and photosynthesis; that is, the thicker the mesophyll cell walls, the lower the gm and photosynthesis. Potential interplays of gm, Tcw, dehydration tolerance, and hydraulic properties of leaves are also discussed. Dynamic variations of Tcw in response to the environment and their implications in the regulation of photosynthesis are discussed, and recent evidence suggesting an influence of cell wall composition on gm is presented. We then propose a hypothetical mechanism for the influence of cell walls on photosynthesis, combining the effects of thickness and composition, particularly pectins. Finally, we discuss the prospects for using biotechnology for enhancing photosynthesis by altering cell wall-related genes.
Resolving discs and mergers in z ∼ 2 heavily reddened quasars and their companion galaxies with ALMA
Authors: Banerji Manda , Jones Gareth C , Carniani Stefano , DeGraf Colin , Wagg Jeff 
Published: March 2021

ABSTRACT
We present sub-arcsecond resolution Atacama Large Millimeter Array imaging of the CO(3–2) emission in two z ∼ 2.5 heavily reddened quasars (HRQs) – ULASJ1234+0907 and ULASJ2315+0143 – and their companion galaxies. Dynamical modelling of the resolved velocity fields enables us to constrain the molecular gas morphologies and host galaxy masses. Combining the new data with extensive multiwavelength observations, we are able to study the relative kinematics of different molecular emission lines, the molecular gas fractions, and the locations of the quasars on the MBH–Mgal relation. Despite having similar black hole properties, the two HRQs display markedly different host galaxy properties and local environments. J1234 has a very massive host – Mdyn ∼ 5 × 1011 M⊙ and two companion galaxies that are similarly massive located within 200 kpc of the quasar. The molecular gas fraction is low (∼6 per cent). The significant ongoing star formation in the host galaxy is entirely obscured at rest-frame ultraviolet (UV) and optical wavelengths. J2315 is resolved into a close-separation major merger (Δr = 15 kpc; Δv = 170 km s−1) with a ∼1:2 mass ratio. The total dynamical mass is estimated to be ≲1011 M⊙ and the molecular gas fraction is high (&gt;45 per cent). A new HSC image of the galaxy shows unobscured UV-luminous star-forming regions co-incident with the extended reservoir of cold molecular gas in the merger. We use the outputs from the Illustris simulations to track the growth of such massive black holes from z ∼ 6 to the present day. While J1234 is consistent with the simulated z ∼ 2 relation, J2315 has a black hole that is overmassive relative to its host galaxy.
Dips and eclipses in the X-ray binary Swift J1858.6–0814 observed with NICER
Authors: Buisson D J K , Altamirano D , Armas Padilla M , Arzoumanian Z , Bult P , Castro Segura N , Charles P A , Degenaar N , Díaz Trigo M , van den Eijnden J , Fogantini F , Gandhi P , Gendreau K , Hare J , Homan J , Knigge C , Malacaria C , Mendez M , Muñoz Darias T , Ng M , Özbey Arabacı M , Remillard R , Strohmayer T E , Tombesi F , Tomsick J A , Vincentelli F , Walton D J 
Published: March 2021

ABSTRACT
We present the discovery of eclipses in the X-ray light curves of the X-ray binary Swift J1858.6–0814. From these, we find an orbital period of $P=76841.3_{-1.4}^{+1.3}$ s (≈21.3 h) and an eclipse duration of $t_{\rm ec}=4098_{-18}^{+17}$ s (≈1.14 h). We also find several absorption dips during the pre-eclipse phase. From the eclipse duration to orbital period ratio, the inclination of the binary orbit is constrained to i &gt; 70°. The most likely range for the companion mass suggests that the inclination is likely to be closer to this value than 90. The eclipses are also consistent with earlier data, in which strong variability (‘flares’) and the long orbital period prevent clear detection of the period or eclipses. We also find that the bright flares occurred preferentially in the post-eclipse phase of the orbit, likely due to increased thickness at the disc-accretion stream interface preventing flares being visible during the pre-eclipse phase. This supports the notion that variable obscuration is responsible for the unusually strong variability in Swift J1858.6–0814.
3D simulations of oxygen shell burning with and without magnetic fields
Authors: Varma Vishnu , Müller Bernhard 
Published: March 2021

ABSTRACT
We present a first 3D magnetohydrodynamic (MHD) simulation of convective oxygen and neon shell burning in a non-rotating $18\, \mathrm{M}_\odot$ star shortly before core collapse to study the generation of magnetic fields in supernova progenitors. We also run a purely hydrodynamic control simulation to gauge the impact of the magnetic fields on the convective flow and on convective boundary mixing. After about 17 convective turnover times, the magnetic field is approaching saturation levels in the oxygen shell with an average field strength of $\mathord {\sim }10^{10}\, \mathrm{G}$, and does not reach kinetic equipartition. The field remains dominated by small-to-medium scales, and the dipole field strength at the base of the oxygen shell is only $10^{9}\, \mathrm{G}$. The angle-averaged diagonal components of the Maxwell stress tensor mirror those of the Reynolds stress tensor, but are about one order of magnitude smaller. The shear flow at the oxygen–neon shell interface creates relatively strong fields parallel to the convective boundary, which noticeably inhibit the turbulent entrainment of neon into the oxygen shell. The reduced ingestion of neon lowers the nuclear energy generation rate in the oxygen shell and thereby slightly slows down the convective flow. Aside from this indirect effect, we find that magnetic fields do not appreciably alter the flow inside the oxygen shell. We discuss the implications of our results for the subsequent core-collapse supernova and stress the need for longer simulations, resolution studies, and an investigation of non-ideal effects for a better understanding of magnetic fields in supernova progenitors.