bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-1093. In Vitro Activity of Eravacycline against Carbapenem-Resistant Acinetobacter baumannii as Evaluated by Broth Microdilution, MIC Test Strip and Disc Diffusion
Authors: Liu Qihui , Li Shirong , Jiang Haoqin , Wang Xuan , Li Ning 
Published: January 2025

Abstract

Background
Eravacycline is a new type of fully synthetic fluorocycline antibiotic. The Chinese Committee on Antimicrobial Susceptibility Testing (ChinaCAST) published the clinical breakpoints of eravacycline, including MIC breakpoints and their inhibition zone diameter correlates. MIC test strip (MTS) is a gradient diffusion method that represents a simple alternative to the broth microdilution (BMD) method for performing antimicrobial susceptibility testing (AST). The aim of this study was to compare the susceptible rate of carbapenem-resistant Acinetobacter baumannii (CRAB) to eravacycline by three different testing methods.

Methods
587 strains of CRAB were collected from the Huashan Hospital affiliated to Fudan University from 2019 to 2023. According to the antimicrobial susceptibility test recommended by the American Society for Clinical and Laboratory Standards 2023, the activity of eravacycline was determined. In this study, the BMD was used as the reference standard, and the clinical breakpoints standard published by ChinaCAST ( Acinetobacter baumannii susceptible MIC, ≤ 1 μg / mL or inhibition zone diameter , ≥ 15 mm ) was used to detect the susceptible rate of eravacycline to CRAB.

Results
The MIC50/90s were as follows: BMD, 0.5/1 mg/L; MTS, 0.38/0.75 mg/L. Based on the BMD method, the susceptible rate of CRAB to eravacycline was 98.13% (576/587) according to the ChinaCAST breakpoints, while 97.96% (575/587) was observed in MTS method. The results of DD method showed that the sensitivity rate was 97.61% (573/587). Compared with the results of BMD, the essential agreement (EA) rate of MTS was 94.55%. The categorical agreement (CA) rates of MTS and DD were 99.83% and 99.49%, respectively. The total major error (ME) rate and total very major error (VME) rate of MTS were 0.17% and 0%, respectively. The total ME rate and total VME rate of DD were 0.51% and 0%, respectively.

Conclusion
The susceptible rate of eravacycline to CRAB is high. CA, ME or VME all met the methodological evaluation indicators. The results of the sensitivity of CRAB to eravacycline determined by MTS and DD methods were similar, and the consistency with the BMD method was good. Both of them can be used as reliable AST methods for the determination of eravacycline antibacterial activity in clinical microbiology laboratories.

Disclosures
All Authors: No reported disclosures
P-1110. The Impact of Xeruborbactam on in vitro Activity of Cefiderocol against a Panel of Enterobacterales Enriched with Isolates with Reduced Cefiderocol Susceptibility
Authors: Hara Takafumi , Ishibashi Naoki , Miyagawa Dai , Onishi Motoyasu , Lomovskaya Olga , Yamano Yoshinori 
Published: January 2025

Abstract

Background
Cefiderocol (CFDC) is a siderophore cephalosporin with potent activity against resistant gram-negative bacteria. According to recent SIDERO-WT surveillance studies that involved testing of &gt; 30,000 Enterobacterales (ENT) isolates collected in North America and Europe, 99.8% of ENT were susceptible (S) to CFDC (by CLSI breakpoint) (MIC90=1 µg/mL). For carbapenem-resistant Enterobacterales (CRE), S to CFDC was as high as 96.5% (MIC90=4 µg/mL). In ENT, resistance to CFDC is multifactorial and seems to require production of either a serine (SBL) or metallo (MBL) carbapenemase. Xeruborbactam (XER) is a novel beta-lactamase inhibitor that inhibits multiple SBL and MBL enzymes. In this study, we evaluated the impact of XER on activity of CFDC against a challenge panel of β-lactamase-producing ENT (BL-ENT) enriched in CFDC-resistant isolates.
MIC50/90 of cefiderocol (CFDC) alone and with xeruborbactam (XER) against Enterobacterales

Methods
A challenge panel of 165 BL-ENT isolates that included 139 CRE was used for this study. 79 (56.8%) and 41 (24.8%) of isolates had CFDC MIC values &gt; 1 µg/mL and &gt; 4 µg/mL (non-S by CLSI/FDA breakpoint), respectively. The β-lactamase profile for each isolate was determined by PCR or whole genome sequencing. MICs were determined for CFDC alone and in combination with 1, 2 or 4 μg/mL of XER according to CLSI guidelines for CFDC using iron-depleted CAMHB.

Results
MIC50/MIC90 of CDFC alone and XER alone against 165 ENT were 2/16 and 16/ &gt; 16 μg/mL, respectively. Dose-dependent shifts of CFDC MICs to the more susceptible range in the presence of increasing concentrations of XER were observed. XER at ≥ 1 μg/mL reduced the MIC90 of CFDC to ≤ 1 μg/mL, which is below the MIC90 for CFDC alone for all ENT in surveillance studies. XER at ≥ 2 μg/mL reduced CFDC MIC90 of MBL producers to ≤ 1 μg/mL For isolates with CFDC MIC &gt; 4 μg/mL, 4 μg/mL of XER reduced the CFDC MIC90 from 32 to 1 μg/mL; the MIC50 for this subset of isolates were reduced from 16 to 0.25 µg/mL, the same MIC50 that were observed for all surveillance isolates.

Conclusion
XER significantly improved the activity of CFDC against rarely encountered isolates of Enterobacterales with elevated CFDC MICs. The potency of CFDC/XER against these isolates was as high as potency of CFDC alone against CFDC susceptible strains.

Disclosures
Takafumi Hara, MSc, SHIONOGI & CO., LTD.: Employee Naoki Ishibashi, MD, SHIONOGI & CO., LTD.: Employee Dai Miyagawa, n/a, SHIONOGI & CO., LTD.: Employee Motoyasu Onishi, PhD, Shionogi & Co., Ltd.: Employee Olga Lomovskaya, PhD, Qpex Biopharma Inc.: Board Member|SHIONOGI & CO., LTD.: Employee Yoshinori Yamano, PhD, Shionogi & Co., Ltd.: Employee
P-1123. Characterization of microbiological isolates in the newborn unit of the San Ignacio university hospital between 2018 and 2022
Authors: Perez Monica Maria , Bertolotto Ana Maria , Del Pilar Montealegre Adriana , Lopez Juan Carlos , Vargas Yaris Anzully , Suarez Maria Alejandra , Gomez Ingrid Mayerly , Cortes Gloria Cecilia 
Published: January 2025

Abstract

Background
Identifying local microbial profiles and antibiotic sensitivities is an important part of antimicrobial stewardship programs in order to prevent overuse of antibiotics. The purpose of this study was to characterize the microbiological isolates from patients hospitalized in the newborn care unit of the Hospital Universitario San Ignacio from January 1, 2018 to December 31, 2022.
Total number of microorganisms isolated
1

Methods
An observational, descriptive, historical single cohort study was conducted. Positive cultures of sterile samples (blood, urine, spinal fluid) from patients hospitalized. Demographic, clinical, and microbiological data of patients with positive cultures were also collected.

Results
A total of 207 positive cultures of sterile samples were identified (97 blood, 108 urines, 2 spinal fluid). The most frequent pathogens isolated were E. coli 28.9%, S. epidermidis 27%, Enterococcus faecalis 11.5%, Klebsiella pneumoniae 8.2% and Staphylococcus aureus 4.8%. E. coli and S. epidermidis being the main microorganisms isolated 28% each were the main pathogens associated with neonatal sepsis (NS). NS was predominantly late-onset &gt;72 hours 94.6%. Early-onset sepsis was less common 5.3% and was associated with E. coli 5.4% and S. agalactiae 18.1%.
Healthcare-associated infections (34.7%), and catheter-associated bloodstream infections (CLABSI) were the most common. Congenital heart disease (P = .000) was the main comorbidity related to CLABSI, as well as gastroschisis (P = 0.002) and intestinal atresia (P = 0.033)
Multidrug-resistant (MDR) microorganisms were isolated in 12 instances (5.8%). Extended Spectrum Beta-Lactamase (ESBL) was 50%. Congenital heart disease was the only comorbidity with a statistically significant relationship with infection by MDR microorganisms (P = 0.026).
Clinical and sociodemographic characteristics of the multidrug-resistant microorganism population.

Conclusion
This is the first study in our environment to know the basal factors of infections in a population at risk, the patterns of resistance and possible association with the most prevalent pathologies and, based on this, to define the strategies of antimicrobial stewardship.

Disclosures
All Authors: No reported disclosures
P-1128. Pilot Cross Sectional Demographic Study of Pediatric Patients with Reported Penicillin Allergy in a Tertiary Rural Regional Health Center
Authors: Feldhaus Kevin , Richter John , Lim Peter Paul , Sass Emily , Reedstrom Hannah , Meeissner Tobias , Deaton McKenna , Borgmann Michael 
Published: January 2025

Abstract

Background
Penicillins remain reliable agents and are considered drugs of choice for select infections.1-3 Approximately 10% of the US population report a penicillin allergy with majority of the labels placed in childhood.4,5 There is a paucity of data describing the role of socio-demographic factors to understand the epidemiology of pediatric penicillin allergy especially in the rural settings.6

Methods
This is a cross sectional retrospective demographic query of pediatric patients 0-18 years old with reported penicillin allergy in the electronic medical record from 2018-2023 in a rural tertiary health system in South Dakota.

Results
Of 350,847 patients, 10,077 (2.9%) were identified with penicillin allergy label. Of which 5,162 (51%) were male. The median age was 11(6,15). There were 8,499 (88%) Caucasians, 432 (4.5%) American Indian/Alaskan Native, 126 (1.3%) Black/African American, 49(0.5%) Asian, and 3(&lt; 0.1%)) Pacific Island/Native Hawaiian. Amoxicillin was the most common reported allergy in 6,738 (67%) patients, penicillin in 3,163 (31%) and Augmentin in 699 (6.9%). Severe reaction was reported in 2,921 (46%) patients with rash being the most common reported reaction in 5,566 (55%). Asthma was identified in 564 (5.6%) patients. Physicians are the primary providers for 5,778 (74%) among which family medicine physicians composed the majority (5,154, 66%). Penicillin allergy labels were recorded by APP/nursing in 7,202 (71.4). Majority of patients had commercial insurance 6,485 (71%) while 2,139 (23%) had government insurance. Patients’ home addresses that could be mapped using the RUCA classification, majority of patients belonged to rural (2,901,37%) and micropolitan (2,867, 37%) areas. Area Deprivation Index median was 66.

Conclusion
Penicillin allergy is most prevalent among Caucasian pediatric patients in our rural health system with Native Americans comprising the majority of other ethnic minorities. Amoxicillin is the most common reported allergy. Heterogeneous severity and characterization of reactions have been reported for these allergies. A small percentage of patients have identified co-morbidities. Socio-demographic factors differ across pediatric patients with penicillin allergies in our cohort with overall ADI suggesting above the national median.

Disclosures
Tobias Meeissner, PhD, BioNTech: Stocks/Bonds (Public Company)|Cellworks: Grant/Research Support|GeneDX: Stocks/Bonds (Public Company)|Labcorp: Grant/Research Support|Tempus: Grant/Research Support
P-1137. Decreasing Empiric Vancomycin use for Orbital Cellulitis in Children
Authors: Downey Rachel , Parihar Nisha , Weston Natalie , Khan Soman , Bhaduri. Hauger Sarmistha , Mincher Alan Wade , Kozak Travis 
Published: January 2025

Abstract

Background
Orbital cellulitis in children is often caused by Staphylococcus aureus, Streptococcus viridans group, and Streptococcus pyogenes. Oral, respiratory, and skin commensals are also considered in empiric antibiotic choice. MRSA is becoming less prevalent nationally.
In 2015, our hospital implemented an evidence-based orbital cellulitis guideline to standardize care and promote antibiotic and surgical stewardship. The guidance calls for empiric clindamycin and ceftriaxone, reserving vancomycin for cases with signs of optic nerve or CNS involvement. Here we evaluate results of this guidance and summarize isolated bacteria.Fig 1.Empiric use of vancomycin pre and post guideline

Methods
Cases were pulled from the hospital chart by diagnosis code and positive computed tomography scan for orbital cellulitis for 4 years pre-guideline and (2009-2013) 7 years post-guideline (2015-2021) implementation and were manually reviewed for clinical diagnosis of orbital cellulitis. Variables collected included demographics, empiric antibiotics, presence of abscess, surgical intervention, bacterial identification by blood or surgical culture, length of stay, and related readmission. Statistic analysis included chi square, fisher's exact test and Wilcoxon ranked sum.Fig 2.Bacteria isolated from blood or surgical culture in all cases*13 cases were polymicrobial

Results
134 cases were included in the analysis (46 pre and 88 post guideline). Median age was 7 in both groups; there was incidentally a significantly higher proportion of males in the post-guideline group (54% v 75%, p=0.025). Post guideline, empiric use of vancomycin significantly decreased from 54% to 23% (p&lt; 0.001) (fig 1). Among cases with vancomycin use post-guidance, 60% of use was concordant with the guideline. Length of stay was reduced from a median of 4 days to 3 days (p=0.001). Rate of abscesses and surgical intervention were nearly identical in pre and post populations (63% with abscess, and 24% with surgery in both groups). Overall, bacterial cultures from blood or abscess were positive in 26% of cases (10 (22%) pre, 25 (28%) post guideline); 13 (37%) were polymicrobial. All 3 MRSA cases were susceptible to clindamycin.

Conclusion
Implementation of a hospital-wide guideline can result in more judicious use of broad spectrum antibiotics. Reduction in vancomycin occurred without increased length of stay, need for surgical intervention, or readmission.

Disclosures
All Authors: No reported disclosures
P-1139. Surveying Antibiotic Treatment for Pediatric Patients with Suspected Urinary Tract Infections at Madigan Army Medical Center
Authors: Lonergan Samantha , Sainato Rebecca , Cirks Blake 
Published: January 2025

Abstract

Background
Urinary tract infections (UTIs) are one of the most common bacterial infections in pediatric patients presenting to the Emergency Department (ED). However, the gold standard for diagnosis is a urine culture which takes 24-48 hours to result leading to antibiotics started empirically while results are pending. This study was implemented with the primary aim of evaluating the antibiotic management of pediatric patients who were seen at a single medical center ED with suspected UTI.

Methods
Using the electronic medical record we identified pediatric cases (ages 2 months-18 years) where UTI was diagnosed in the ED during 2023 using the ICD-10 code. Data collected on each case included demographics, laboratory work-up, prescribed medications, and follow-up. Outcomes were categorized as confirmed, unknown, or negated. A confirmed UTI required an abnormal urinalysis and single species growth exceeding 50,000 cfu/mL; UTI was negated when growth was &lt; 10,000 cfu/mL. Descriptive statistics and comparison tests were used as appropriate.

Results
There were 80 UTI diagnoses in 70 patients. 18 (22.5%) cases were confirmed and 36 (45%) were negated (Table 1). We analyzed 54 cases with confirmed or negated UTIs: 15 (27.8%) had follow-up with primary care (PCM) within 96 hours of their ED visit. When UTI was negated, 4 cases (11%) had antibiotics discontinued and all had PCM follow-up within 96 hours (p=0.043) (Table 2). Enterococcus-UTI accounted for 75% of cases where empiric treatment was inadequate. Of those without confirmed UTI, 3 returned to the ED with adverse effects from antibiotics and 2 with multiple inconclusive evaluations were referred to urology. The ED providers notified families with positive urine culture results, but no one was notified if the urine culture was negative.

Conclusion
Many pediatric patients who are treated for UTI in our ED have inconclusive or negative workups resulting in unnecessary antibiotic use, ED visits for antibiotic complications, and subspecialty referrals. Our current system does not support the discontinuation or tailoring of unnecessary or inappropriate antibiotics unless patients have close follow-up. Antibiotic stewardship requires systematic support within the ED to limit unnecessary antibiotics and the inherent complications that follow.

Disclosures
All Authors: No reported disclosures
P-1150. Prospective case-control study to examine clinical, biochemical, and serological indicators to predict Staphylococcal scalded skin syndrome
Authors: Mitra Barnali , Mitra Debdeep 
Published: January 2025

Abstract

Background
Staphylococcal scalded skin syndrome (SSSS) typically affects infants & children, with rare occurrences in adults. There is no rapid tool or any scoring system to diagnose SSSS, where early diagnosis is the key to successful outcome.

Methods
This study evaluates specific clinical & serological indicators to distinguish between maculopapular eruption & SSSS upon initial presentation. Additionally, we investigate the correlation between serum levels of thymus and activation-regulated chemokine (TARC) & the severity of SSSS & the extent of organ involvement.
In this observational study conducted prospectively, 25 patients diagnosed with SSSS & 25 control subjects with maculopapular rash were enrolled.

Results
The diagnostic efficacy of various factors, including TARC level ( &gt;612.25 pg/ml), total body surface area (TBSA &gt;30%), hsCRP ( &gt;5mg/l), leucocytosis ( &gt;12X 109 cells/L), & aspartate transaminase ( &gt;90 U/L), showed statistical similarity to the diagnosis of SSSS. While baseline serum TARC levels proved to be a reliable screening tool, they did not predict the severity or outcome of SSSS. However neutrophil extracellular traps (NETs) level did correlate positively with disease severity & duration of hospital stay.
Through multivariable regression analysis, we have formulated a novel model that integrates TBSA at baseline, neutrophil percentage in leucocytosis, & hsCRP, surpassing the predictive capacity of these parameters when considered individually. The resulting equation with the highest odds for diagnosing SSSS is as follows:
Odds of SSSS (present) = Antilog [-11.26 + 0.3 x Total BSA + 0.30 x hsCRP – 0.1 x neutrophil (%)].
This composite model (incorporating TBSA at baseline, neutrophil percentage, and hsCRP) achieved a sensitivity of 96% and specificity of 100% at a cutoff point of 7.8.

Conclusion
The equation developed from our research is straightforward to apply and suitable for use in settings with limited resources. It facilitates the identification of patients who are more likely to have SSSS, enabling the early initiation of definitive treatment. Likewise, it helps in minimizing unnecessary extensive investigations for patients unlikely to have SSSS. Neutrophil extracellular traps (NET) can be definitely used as a prognostic marker in patients with severe SSSS.

Disclosures
All Authors: No reported disclosures
P-1166. Outcome of Fungemia Caused by Yeast in Children: Significance of Breakthrough Fungemia and Source Identification
Authors: Kasai Taketo , Yamada Masaki , Funaki Takanori , Ogimi Chikara 
Published: January 2025

Abstract

Background
Fungemia by yeast is a life-threatening infection that occurs in patients with special conditions. It is often identified by its morphology, triggering the empiric therapy. However, the management can be difficult as identification and susceptibility tests require several days, and evidence on management and outcomes in pediatric patients is limited. Thus, this study aimed to characterize pediatric fungemia by yeast and assess their outcomes to help optimize management.
Risk factor analysis for overall mortality following fungemia by yeast

Methods
This is a single-center, retrospective observational study at the largest tertiary children’s hospital in Japan. Electronic medical records of pediatric patients &lt; 18 years who developed fungemia by yeast from April 2014 to March 2024 were reviewed. To simplify, the data on the first fungemia by yeast was collected on patients with multiple episodes, along with patient characteristics, details of identified organisms, use of antifungals, and prognosis. Breakthrough fungemia was defined when it occurred during the use of systemic antifungals for ≥ 3 days. Descriptive data, the risk for overall mortality and survival following fungemia were analyzed using chi-square test and Kaplan-Meier curve analysis with a p-value &lt; 0.05 being considered significant.
Overall survival following fungemia by yeast according to prior use of antifungals

Results
Overall, 55 episodes of fungemia by yeast were identified in 43 patients. 28/43 (65%) patients were immunocompromised. Candida parapsilosis was the most frequently detected (20/43, 47%), followed by C. albicans (11/43, 26%). Breakthrough fungemia occurred in 17/43 (40%) cases. Mortality was significantly higher in patients with breakthrough fungemia compared to those without prior antifungals (8/17 (47%) vs. 2/26 (8%), p&lt; 0.01). In addition, when the source of fungemia was clinically undetermined, the overall mortality rate was high (8/17, 47%, p&lt; 0.01) (Table). Further, the survival curve after the onset of fungemia by yeast depicted the worse outcomes in patients with breakthrough fungemia (p&lt; 0.01) (Figure).

Conclusion
In pediatric patients with fungemia by yeast, the mortality rate was higher in breakthrough fungemia and fungemia with unknown sources. Therefore, it is crucial to recognize the importance of breakthrough fungemia and identifying the source of infection to pursue appropriate source control.

Disclosures
Chikara Ogimi, MD, PhD, AstraZeneca: Honoraria|bioMerieux Japan Ltd.: Honoraria|ELSEVIER: Honoraria|KYORIN: Honoraria|Miyarisan: Honoraria|MSD: Honoraria|NOVARTIS: Honoraria|Pfizer: Honoraria
P-1170. Impact of Healthcare-associated Respiratory Virus Infections in Children
Authors: Miyashita Aki , Horikoshi Yuho , Funakoshi Hanako , Shibata Meiwa , Nakamura Keiko , Miyokawa Shigeko 
Published: January 2025

Abstract

Background
Respiratory viruses can spread within healthcare facilities despite stringent infection prevention measures. Although healthcare-associated respiratory virus infections (HARVI) pose a significant risk to children, pediatric HARVI are understudied. The present study aimed to evaluate the impact of HARVI on children following the SARS-CoV-2 pandemic at a tertiary children’s hospital.

Methods
This retrospective study enrolled pediatric inpatients aged ≤18 years who were hospitalized at Tokyo Metropolitan Children's Medical Center between April 2020 and March 2024. HARVI was defined as a viral infection with a new onset of respiratory symptoms past the incubation period following hospitalization. The causative virus was detected using multiplex PCR (FilmArray Respiratory Panel 2.1, BioFire). Patients with other infections were excluded. The primary outcome was the 30-day mortality rate. The secondary outcomes included PICU admission, escalation of respiratory support, and the postponement of discharge, planned surgery or chemotherapy.

Results
In total, 265 patients with HARVI were enrolled. Male patients comprised 31% of the cohort, and the median age was 31 (IQR [interquartile range]: 12-77) months. Underlying neurologic, cardiac, and congenital or genetic disorders had in 42%, 28%, and 24% of the cohort, respectively. The respiratory viruses detected were the rhinovirus/enterovirus (44%), parainfluenza virus type 3 (15%), and HKU1, NL63, 229E and OC43 coronaviruses (8%). The 30-day mortality rate was 1% in three patients with parainfluenza virus type 3, RSV, and SARS-CoV-2. The PICU admission rate was 2%. The rate of respiratory support escalation was 17%. Postponement of discharge was required in 7% of the cohort for a median period of seven (IQR: 5-8) days. Postponement of surgery was required in 3% of the cohort for a median period of 46 (IQR: 21-82) days. There was no postponement of chemotherapy.

Conclusion
Pediatric HARVI was associated with mortality and additional medical care. Therefore, strict infection prevention measures are essential.

Disclosures
Hanako Funakoshi, MD, Pfizer Japan: Husband is an employee.